diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/LICENSE b/vendor/github.com/masterzen/azure-sdk-for-go/LICENSE
new file mode 100644
index 000000000..af39a91e7
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/LICENSE
@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
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+      direction or management of such entity, whether by contract or
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+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
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+      "Contributor" shall mean Licensor and any individual or Legal Entity
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+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
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+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
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+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
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+
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+      meet the following conditions:
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+          Derivative Works a copy of this License; and
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+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
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+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
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+      whether in tort (including negligence), contract, or otherwise,
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+      negligent acts) or agreed to in writing, shall any Contributor be
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+      defend, and hold each Contributor harmless for any liability
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+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
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+
+   Copyright 2016 Microsoft Corporation
+
+   Licensed under the Apache License, Version 2.0 (the "License");
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+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/http/chunked.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/chunked.go
new file mode 100644
index 000000000..749f29d32
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/chunked.go
@@ -0,0 +1,203 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// The wire protocol for HTTP's "chunked" Transfer-Encoding.
+
+// This code is duplicated in net/http and net/http/httputil.
+// Please make any changes in both files.
+
+package http
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+)
+
+const maxLineLength = 4096 // assumed <= bufio.defaultBufSize
+
+var ErrLineTooLong = errors.New("header line too long")
+
+// newChunkedReader returns a new chunkedReader that translates the data read from r
+// out of HTTP "chunked" format before returning it.
+// The chunkedReader returns io.EOF when the final 0-length chunk is read.
+//
+// newChunkedReader is not needed by normal applications. The http package
+// automatically decodes chunking when reading response bodies.
+func newChunkedReader(r io.Reader) io.Reader {
+	br, ok := r.(*bufio.Reader)
+	if !ok {
+		br = bufio.NewReader(r)
+	}
+	return &chunkedReader{r: br}
+}
+
+type chunkedReader struct {
+	r   *bufio.Reader
+	n   uint64 // unread bytes in chunk
+	err error
+	buf [2]byte
+}
+
+func (cr *chunkedReader) beginChunk() {
+	// chunk-size CRLF
+	var line []byte
+	line, cr.err = readLine(cr.r)
+	if cr.err != nil {
+		return
+	}
+	cr.n, cr.err = parseHexUint(line)
+	if cr.err != nil {
+		return
+	}
+	if cr.n == 0 {
+		cr.err = io.EOF
+	}
+}
+
+func (cr *chunkedReader) chunkHeaderAvailable() bool {
+	n := cr.r.Buffered()
+	if n > 0 {
+		peek, _ := cr.r.Peek(n)
+		return bytes.IndexByte(peek, '\n') >= 0
+	}
+	return false
+}
+
+func (cr *chunkedReader) Read(b []uint8) (n int, err error) {
+	for cr.err == nil {
+		if cr.n == 0 {
+			if n > 0 && !cr.chunkHeaderAvailable() {
+				// We've read enough. Don't potentially block
+				// reading a new chunk header.
+				break
+			}
+			cr.beginChunk()
+			continue
+		}
+		if len(b) == 0 {
+			break
+		}
+		rbuf := b
+		if uint64(len(rbuf)) > cr.n {
+			rbuf = rbuf[:cr.n]
+		}
+		var n0 int
+		n0, cr.err = cr.r.Read(rbuf)
+		n += n0
+		b = b[n0:]
+		cr.n -= uint64(n0)
+		// If we're at the end of a chunk, read the next two
+		// bytes to verify they are "\r\n".
+		if cr.n == 0 && cr.err == nil {
+			if _, cr.err = io.ReadFull(cr.r, cr.buf[:2]); cr.err == nil {
+				if cr.buf[0] != '\r' || cr.buf[1] != '\n' {
+					cr.err = errors.New("malformed chunked encoding")
+				}
+			}
+		}
+	}
+	return n, cr.err
+}
+
+// Read a line of bytes (up to \n) from b.
+// Give up if the line exceeds maxLineLength.
+// The returned bytes are a pointer into storage in
+// the bufio, so they are only valid until the next bufio read.
+func readLine(b *bufio.Reader) (p []byte, err error) {
+	if p, err = b.ReadSlice('\n'); err != nil {
+		// We always know when EOF is coming.
+		// If the caller asked for a line, there should be a line.
+		if err == io.EOF {
+			err = io.ErrUnexpectedEOF
+		} else if err == bufio.ErrBufferFull {
+			err = ErrLineTooLong
+		}
+		return nil, err
+	}
+	if len(p) >= maxLineLength {
+		return nil, ErrLineTooLong
+	}
+	return trimTrailingWhitespace(p), nil
+}
+
+func trimTrailingWhitespace(b []byte) []byte {
+	for len(b) > 0 && isASCIISpace(b[len(b)-1]) {
+		b = b[:len(b)-1]
+	}
+	return b
+}
+
+func isASCIISpace(b byte) bool {
+	return b == ' ' || b == '\t' || b == '\n' || b == '\r'
+}
+
+// newChunkedWriter returns a new chunkedWriter that translates writes into HTTP
+// "chunked" format before writing them to w. Closing the returned chunkedWriter
+// sends the final 0-length chunk that marks the end of the stream.
+//
+// newChunkedWriter is not needed by normal applications. The http
+// package adds chunking automatically if handlers don't set a
+// Content-Length header. Using newChunkedWriter inside a handler
+// would result in double chunking or chunking with a Content-Length
+// length, both of which are wrong.
+func newChunkedWriter(w io.Writer) io.WriteCloser {
+	return &chunkedWriter{w}
+}
+
+// Writing to chunkedWriter translates to writing in HTTP chunked Transfer
+// Encoding wire format to the underlying Wire chunkedWriter.
+type chunkedWriter struct {
+	Wire io.Writer
+}
+
+// Write the contents of data as one chunk to Wire.
+// NOTE: Note that the corresponding chunk-writing procedure in Conn.Write has
+// a bug since it does not check for success of io.WriteString
+func (cw *chunkedWriter) Write(data []byte) (n int, err error) {
+
+	// Don't send 0-length data. It looks like EOF for chunked encoding.
+	if len(data) == 0 {
+		return 0, nil
+	}
+
+	if _, err = fmt.Fprintf(cw.Wire, "%x\r\n", len(data)); err != nil {
+		return 0, err
+	}
+	if n, err = cw.Wire.Write(data); err != nil {
+		return
+	}
+	if n != len(data) {
+		err = io.ErrShortWrite
+		return
+	}
+	_, err = io.WriteString(cw.Wire, "\r\n")
+
+	return
+}
+
+func (cw *chunkedWriter) Close() error {
+	_, err := io.WriteString(cw.Wire, "0\r\n")
+	return err
+}
+
+func parseHexUint(v []byte) (n uint64, err error) {
+	for _, b := range v {
+		n <<= 4
+		switch {
+		case '0' <= b && b <= '9':
+			b = b - '0'
+		case 'a' <= b && b <= 'f':
+			b = b - 'a' + 10
+		case 'A' <= b && b <= 'F':
+			b = b - 'A' + 10
+		default:
+			return 0, errors.New("invalid byte in chunk length")
+		}
+		n |= uint64(b)
+	}
+	return
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/http/client.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/client.go
new file mode 100644
index 000000000..a5a3abe61
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/client.go
@@ -0,0 +1,487 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// HTTP client. See RFC 2616.
+//
+// This is the high-level Client interface.
+// The low-level implementation is in transport.go.
+
+package http
+
+import (
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"net/url"
+	"strings"
+	"sync"
+	"time"
+)
+
+// A Client is an HTTP client. Its zero value (DefaultClient) is a
+// usable client that uses DefaultTransport.
+//
+// The Client's Transport typically has internal state (cached TCP
+// connections), so Clients should be reused instead of created as
+// needed. Clients are safe for concurrent use by multiple goroutines.
+//
+// A Client is higher-level than a RoundTripper (such as Transport)
+// and additionally handles HTTP details such as cookies and
+// redirects.
+type Client struct {
+	// Transport specifies the mechanism by which individual
+	// HTTP requests are made.
+	// If nil, DefaultTransport is used.
+	Transport RoundTripper
+
+	// CheckRedirect specifies the policy for handling redirects.
+	// If CheckRedirect is not nil, the client calls it before
+	// following an HTTP redirect. The arguments req and via are
+	// the upcoming request and the requests made already, oldest
+	// first. If CheckRedirect returns an error, the Client's Get
+	// method returns both the previous Response and
+	// CheckRedirect's error (wrapped in a url.Error) instead of
+	// issuing the Request req.
+	//
+	// If CheckRedirect is nil, the Client uses its default policy,
+	// which is to stop after 10 consecutive requests.
+	CheckRedirect func(req *Request, via []*Request) error
+
+	// Jar specifies the cookie jar.
+	// If Jar is nil, cookies are not sent in requests and ignored
+	// in responses.
+	Jar CookieJar
+
+	// Timeout specifies a time limit for requests made by this
+	// Client. The timeout includes connection time, any
+	// redirects, and reading the response body. The timer remains
+	// running after Get, Head, Post, or Do return and will
+	// interrupt reading of the Response.Body.
+	//
+	// A Timeout of zero means no timeout.
+	//
+	// The Client's Transport must support the CancelRequest
+	// method or Client will return errors when attempting to make
+	// a request with Get, Head, Post, or Do. Client's default
+	// Transport (DefaultTransport) supports CancelRequest.
+	Timeout time.Duration
+}
+
+// DefaultClient is the default Client and is used by Get, Head, and Post.
+var DefaultClient = &Client{}
+
+// RoundTripper is an interface representing the ability to execute a
+// single HTTP transaction, obtaining the Response for a given Request.
+//
+// A RoundTripper must be safe for concurrent use by multiple
+// goroutines.
+type RoundTripper interface {
+	// RoundTrip executes a single HTTP transaction, returning
+	// the Response for the request req.  RoundTrip should not
+	// attempt to interpret the response.  In particular,
+	// RoundTrip must return err == nil if it obtained a response,
+	// regardless of the response's HTTP status code.  A non-nil
+	// err should be reserved for failure to obtain a response.
+	// Similarly, RoundTrip should not attempt to handle
+	// higher-level protocol details such as redirects,
+	// authentication, or cookies.
+	//
+	// RoundTrip should not modify the request, except for
+	// consuming and closing the Body, including on errors. The
+	// request's URL and Header fields are guaranteed to be
+	// initialized.
+	RoundTrip(*Request) (*Response, error)
+}
+
+// Given a string of the form "host", "host:port", or "[ipv6::address]:port",
+// return true if the string includes a port.
+func hasPort(s string) bool { return strings.LastIndex(s, ":") > strings.LastIndex(s, "]") }
+
+// Used in Send to implement io.ReadCloser by bundling together the
+// bufio.Reader through which we read the response, and the underlying
+// network connection.
+type readClose struct {
+	io.Reader
+	io.Closer
+}
+
+func (c *Client) send(req *Request) (*Response, error) {
+	if c.Jar != nil {
+		for _, cookie := range c.Jar.Cookies(req.URL) {
+			req.AddCookie(cookie)
+		}
+	}
+	resp, err := send(req, c.transport())
+	if err != nil {
+		return nil, err
+	}
+	if c.Jar != nil {
+		if rc := resp.Cookies(); len(rc) > 0 {
+			c.Jar.SetCookies(req.URL, rc)
+		}
+	}
+	return resp, err
+}
+
+// Do sends an HTTP request and returns an HTTP response, following
+// policy (e.g. redirects, cookies, auth) as configured on the client.
+//
+// An error is returned if caused by client policy (such as
+// CheckRedirect), or if there was an HTTP protocol error.
+// A non-2xx response doesn't cause an error.
+//
+// When err is nil, resp always contains a non-nil resp.Body.
+//
+// Callers should close resp.Body when done reading from it. If
+// resp.Body is not closed, the Client's underlying RoundTripper
+// (typically Transport) may not be able to re-use a persistent TCP
+// connection to the server for a subsequent "keep-alive" request.
+//
+// The request Body, if non-nil, will be closed by the underlying
+// Transport, even on errors.
+//
+// Generally Get, Post, or PostForm will be used instead of Do.
+func (c *Client) Do(req *Request) (resp *Response, err error) {
+	if req.Method == "GET" || req.Method == "HEAD" {
+		return c.doFollowingRedirects(req, shouldRedirectGet)
+	}
+	if req.Method == "POST" || req.Method == "PUT" {
+		return c.doFollowingRedirects(req, shouldRedirectPost)
+	}
+	return c.send(req)
+}
+
+func (c *Client) transport() RoundTripper {
+	if c.Transport != nil {
+		return c.Transport
+	}
+	return DefaultTransport
+}
+
+// send issues an HTTP request.
+// Caller should close resp.Body when done reading from it.
+func send(req *Request, t RoundTripper) (resp *Response, err error) {
+	if t == nil {
+		req.closeBody()
+		return nil, errors.New("http: no Client.Transport or DefaultTransport")
+	}
+
+	if req.URL == nil {
+		req.closeBody()
+		return nil, errors.New("http: nil Request.URL")
+	}
+
+	if req.RequestURI != "" {
+		req.closeBody()
+		return nil, errors.New("http: Request.RequestURI can't be set in client requests.")
+	}
+
+	// Most the callers of send (Get, Post, et al) don't need
+	// Headers, leaving it uninitialized.  We guarantee to the
+	// Transport that this has been initialized, though.
+	if req.Header == nil {
+		req.Header = make(Header)
+	}
+
+	if u := req.URL.User; u != nil {
+		username := u.Username()
+		password, _ := u.Password()
+		req.Header.Set("Authorization", "Basic "+basicAuth(username, password))
+	}
+	resp, err = t.RoundTrip(req)
+	if err != nil {
+		if resp != nil {
+			log.Printf("RoundTripper returned a response & error; ignoring response")
+		}
+		return nil, err
+	}
+	return resp, nil
+}
+
+// See 2 (end of page 4) http://www.ietf.org/rfc/rfc2617.txt
+// "To receive authorization, the client sends the userid and password,
+// separated by a single colon (":") character, within a base64
+// encoded string in the credentials."
+// It is not meant to be urlencoded.
+func basicAuth(username, password string) string {
+	auth := username + ":" + password
+	return base64.StdEncoding.EncodeToString([]byte(auth))
+}
+
+// True if the specified HTTP status code is one for which the Get utility should
+// automatically redirect.
+func shouldRedirectGet(statusCode int) bool {
+	switch statusCode {
+	case StatusMovedPermanently, StatusFound, StatusSeeOther, StatusTemporaryRedirect:
+		return true
+	}
+	return false
+}
+
+// True if the specified HTTP status code is one for which the Post utility should
+// automatically redirect.
+func shouldRedirectPost(statusCode int) bool {
+	switch statusCode {
+	case StatusFound, StatusSeeOther:
+		return true
+	}
+	return false
+}
+
+// Get issues a GET to the specified URL.  If the response is one of the following
+// redirect codes, Get follows the redirect, up to a maximum of 10 redirects:
+//
+//    301 (Moved Permanently)
+//    302 (Found)
+//    303 (See Other)
+//    307 (Temporary Redirect)
+//
+// An error is returned if there were too many redirects or if there
+// was an HTTP protocol error. A non-2xx response doesn't cause an
+// error.
+//
+// When err is nil, resp always contains a non-nil resp.Body.
+// Caller should close resp.Body when done reading from it.
+//
+// Get is a wrapper around DefaultClient.Get.
+func Get(url string) (resp *Response, err error) {
+	return DefaultClient.Get(url)
+}
+
+// Get issues a GET to the specified URL.  If the response is one of the
+// following redirect codes, Get follows the redirect after calling the
+// Client's CheckRedirect function.
+//
+//    301 (Moved Permanently)
+//    302 (Found)
+//    303 (See Other)
+//    307 (Temporary Redirect)
+//
+// An error is returned if the Client's CheckRedirect function fails
+// or if there was an HTTP protocol error. A non-2xx response doesn't
+// cause an error.
+//
+// When err is nil, resp always contains a non-nil resp.Body.
+// Caller should close resp.Body when done reading from it.
+func (c *Client) Get(url string) (resp *Response, err error) {
+	req, err := NewRequest("GET", url, nil)
+	if err != nil {
+		return nil, err
+	}
+	return c.doFollowingRedirects(req, shouldRedirectGet)
+}
+
+func (c *Client) doFollowingRedirects(ireq *Request, shouldRedirect func(int) bool) (resp *Response, err error) {
+	var base *url.URL
+	redirectChecker := c.CheckRedirect
+	if redirectChecker == nil {
+		redirectChecker = defaultCheckRedirect
+	}
+	var via []*Request
+
+	if ireq.URL == nil {
+		ireq.closeBody()
+		return nil, errors.New("http: nil Request.URL")
+	}
+
+	var reqmu sync.Mutex // guards req
+	req := ireq
+
+	var timer *time.Timer
+	if c.Timeout > 0 {
+		type canceler interface {
+			CancelRequest(*Request)
+		}
+		tr, ok := c.transport().(canceler)
+		if !ok {
+			return nil, fmt.Errorf("net/http: Client Transport of type %T doesn't support CancelRequest; Timeout not supported", c.transport())
+		}
+		timer = time.AfterFunc(c.Timeout, func() {
+			reqmu.Lock()
+			defer reqmu.Unlock()
+			tr.CancelRequest(req)
+		})
+	}
+
+	urlStr := "" // next relative or absolute URL to fetch (after first request)
+	redirectFailed := false
+	for redirect := 0; ; redirect++ {
+		if redirect != 0 {
+			nreq := new(Request)
+			nreq.Method = ireq.Method
+			if ireq.Method == "POST" || ireq.Method == "PUT" {
+				nreq.Method = "GET"
+			}
+			nreq.Header = make(Header)
+			nreq.URL, err = base.Parse(urlStr)
+			if err != nil {
+				break
+			}
+			if len(via) > 0 {
+				// Add the Referer header.
+				lastReq := via[len(via)-1]
+				if lastReq.URL.Scheme != "https" {
+					nreq.Header.Set("Referer", lastReq.URL.String())
+				}
+
+				err = redirectChecker(nreq, via)
+				if err != nil {
+					redirectFailed = true
+					break
+				}
+			}
+			reqmu.Lock()
+			req = nreq
+			reqmu.Unlock()
+		}
+
+		urlStr = req.URL.String()
+		if resp, err = c.send(req); err != nil {
+			break
+		}
+
+		if shouldRedirect(resp.StatusCode) {
+			// Read the body if small so underlying TCP connection will be re-used.
+			// No need to check for errors: if it fails, Transport won't reuse it anyway.
+			const maxBodySlurpSize = 2 << 10
+			if resp.ContentLength == -1 || resp.ContentLength <= maxBodySlurpSize {
+				io.CopyN(ioutil.Discard, resp.Body, maxBodySlurpSize)
+			}
+			resp.Body.Close()
+			if urlStr = resp.Header.Get("Location"); urlStr == "" {
+				err = errors.New(fmt.Sprintf("%d response missing Location header", resp.StatusCode))
+				break
+			}
+			base = req.URL
+			via = append(via, req)
+			continue
+		}
+		if timer != nil {
+			resp.Body = &cancelTimerBody{timer, resp.Body}
+		}
+		return resp, nil
+	}
+
+	method := ireq.Method
+	urlErr := &url.Error{
+		Op:  method[0:1] + strings.ToLower(method[1:]),
+		URL: urlStr,
+		Err: err,
+	}
+
+	if redirectFailed {
+		// Special case for Go 1 compatibility: return both the response
+		// and an error if the CheckRedirect function failed.
+		// See http://golang.org/issue/3795
+		return resp, urlErr
+	}
+
+	if resp != nil {
+		resp.Body.Close()
+	}
+	return nil, urlErr
+}
+
+func defaultCheckRedirect(req *Request, via []*Request) error {
+	if len(via) >= 10 {
+		return errors.New("stopped after 10 redirects")
+	}
+	return nil
+}
+
+// Post issues a POST to the specified URL.
+//
+// Caller should close resp.Body when done reading from it.
+//
+// Post is a wrapper around DefaultClient.Post
+func Post(url string, bodyType string, body io.Reader) (resp *Response, err error) {
+	return DefaultClient.Post(url, bodyType, body)
+}
+
+// Post issues a POST to the specified URL.
+//
+// Caller should close resp.Body when done reading from it.
+//
+// If the provided body is also an io.Closer, it is closed after the
+// request.
+func (c *Client) Post(url string, bodyType string, body io.Reader) (resp *Response, err error) {
+	req, err := NewRequest("POST", url, body)
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Content-Type", bodyType)
+	return c.doFollowingRedirects(req, shouldRedirectPost)
+}
+
+// PostForm issues a POST to the specified URL, with data's keys and
+// values URL-encoded as the request body.
+//
+// When err is nil, resp always contains a non-nil resp.Body.
+// Caller should close resp.Body when done reading from it.
+//
+// PostForm is a wrapper around DefaultClient.PostForm
+func PostForm(url string, data url.Values) (resp *Response, err error) {
+	return DefaultClient.PostForm(url, data)
+}
+
+// PostForm issues a POST to the specified URL,
+// with data's keys and values urlencoded as the request body.
+//
+// When err is nil, resp always contains a non-nil resp.Body.
+// Caller should close resp.Body when done reading from it.
+func (c *Client) PostForm(url string, data url.Values) (resp *Response, err error) {
+	return c.Post(url, "application/x-www-form-urlencoded", strings.NewReader(data.Encode()))
+}
+
+// Head issues a HEAD to the specified URL.  If the response is one of the
+// following redirect codes, Head follows the redirect after calling the
+// Client's CheckRedirect function.
+//
+//    301 (Moved Permanently)
+//    302 (Found)
+//    303 (See Other)
+//    307 (Temporary Redirect)
+//
+// Head is a wrapper around DefaultClient.Head
+func Head(url string) (resp *Response, err error) {
+	return DefaultClient.Head(url)
+}
+
+// Head issues a HEAD to the specified URL.  If the response is one of the
+// following redirect codes, Head follows the redirect after calling the
+// Client's CheckRedirect function.
+//
+//    301 (Moved Permanently)
+//    302 (Found)
+//    303 (See Other)
+//    307 (Temporary Redirect)
+func (c *Client) Head(url string) (resp *Response, err error) {
+	req, err := NewRequest("HEAD", url, nil)
+	if err != nil {
+		return nil, err
+	}
+	return c.doFollowingRedirects(req, shouldRedirectGet)
+}
+
+type cancelTimerBody struct {
+	t  *time.Timer
+	rc io.ReadCloser
+}
+
+func (b *cancelTimerBody) Read(p []byte) (n int, err error) {
+	n, err = b.rc.Read(p)
+	if err == io.EOF {
+		b.t.Stop()
+	}
+	return
+}
+
+func (b *cancelTimerBody) Close() error {
+	err := b.rc.Close()
+	b.t.Stop()
+	return err
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/http/cookie.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/cookie.go
new file mode 100644
index 000000000..dc60ba87f
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/cookie.go
@@ -0,0 +1,363 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package http
+
+import (
+	"bytes"
+	"fmt"
+	"log"
+	"net"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// This implementation is done according to RFC 6265:
+//
+//    http://tools.ietf.org/html/rfc6265
+
+// A Cookie represents an HTTP cookie as sent in the Set-Cookie header of an
+// HTTP response or the Cookie header of an HTTP request.
+type Cookie struct {
+	Name       string
+	Value      string
+	Path       string
+	Domain     string
+	Expires    time.Time
+	RawExpires string
+
+	// MaxAge=0 means no 'Max-Age' attribute specified.
+	// MaxAge<0 means delete cookie now, equivalently 'Max-Age: 0'
+	// MaxAge>0 means Max-Age attribute present and given in seconds
+	MaxAge   int
+	Secure   bool
+	HttpOnly bool
+	Raw      string
+	Unparsed []string // Raw text of unparsed attribute-value pairs
+}
+
+// readSetCookies parses all "Set-Cookie" values from
+// the header h and returns the successfully parsed Cookies.
+func readSetCookies(h Header) []*Cookie {
+	cookies := []*Cookie{}
+	for _, line := range h["Set-Cookie"] {
+		parts := strings.Split(strings.TrimSpace(line), ";")
+		if len(parts) == 1 && parts[0] == "" {
+			continue
+		}
+		parts[0] = strings.TrimSpace(parts[0])
+		j := strings.Index(parts[0], "=")
+		if j < 0 {
+			continue
+		}
+		name, value := parts[0][:j], parts[0][j+1:]
+		if !isCookieNameValid(name) {
+			continue
+		}
+		value, success := parseCookieValue(value)
+		if !success {
+			continue
+		}
+		c := &Cookie{
+			Name:  name,
+			Value: value,
+			Raw:   line,
+		}
+		for i := 1; i < len(parts); i++ {
+			parts[i] = strings.TrimSpace(parts[i])
+			if len(parts[i]) == 0 {
+				continue
+			}
+
+			attr, val := parts[i], ""
+			if j := strings.Index(attr, "="); j >= 0 {
+				attr, val = attr[:j], attr[j+1:]
+			}
+			lowerAttr := strings.ToLower(attr)
+			val, success = parseCookieValue(val)
+			if !success {
+				c.Unparsed = append(c.Unparsed, parts[i])
+				continue
+			}
+			switch lowerAttr {
+			case "secure":
+				c.Secure = true
+				continue
+			case "httponly":
+				c.HttpOnly = true
+				continue
+			case "domain":
+				c.Domain = val
+				continue
+			case "max-age":
+				secs, err := strconv.Atoi(val)
+				if err != nil || secs != 0 && val[0] == '0' {
+					break
+				}
+				if secs <= 0 {
+					c.MaxAge = -1
+				} else {
+					c.MaxAge = secs
+				}
+				continue
+			case "expires":
+				c.RawExpires = val
+				exptime, err := time.Parse(time.RFC1123, val)
+				if err != nil {
+					exptime, err = time.Parse("Mon, 02-Jan-2006 15:04:05 MST", val)
+					if err != nil {
+						c.Expires = time.Time{}
+						break
+					}
+				}
+				c.Expires = exptime.UTC()
+				continue
+			case "path":
+				c.Path = val
+				continue
+			}
+			c.Unparsed = append(c.Unparsed, parts[i])
+		}
+		cookies = append(cookies, c)
+	}
+	return cookies
+}
+
+// SetCookie adds a Set-Cookie header to the provided ResponseWriter's headers.
+func SetCookie(w ResponseWriter, cookie *Cookie) {
+	w.Header().Add("Set-Cookie", cookie.String())
+}
+
+// String returns the serialization of the cookie for use in a Cookie
+// header (if only Name and Value are set) or a Set-Cookie response
+// header (if other fields are set).
+func (c *Cookie) String() string {
+	var b bytes.Buffer
+	fmt.Fprintf(&b, "%s=%s", sanitizeCookieName(c.Name), sanitizeCookieValue(c.Value))
+	if len(c.Path) > 0 {
+		fmt.Fprintf(&b, "; Path=%s", sanitizeCookiePath(c.Path))
+	}
+	if len(c.Domain) > 0 {
+		if validCookieDomain(c.Domain) {
+			// A c.Domain containing illegal characters is not
+			// sanitized but simply dropped which turns the cookie
+			// into a host-only cookie. A leading dot is okay
+			// but won't be sent.
+			d := c.Domain
+			if d[0] == '.' {
+				d = d[1:]
+			}
+			fmt.Fprintf(&b, "; Domain=%s", d)
+		} else {
+			log.Printf("net/http: invalid Cookie.Domain %q; dropping domain attribute",
+				c.Domain)
+		}
+	}
+	if c.Expires.Unix() > 0 {
+		fmt.Fprintf(&b, "; Expires=%s", c.Expires.UTC().Format(time.RFC1123))
+	}
+	if c.MaxAge > 0 {
+		fmt.Fprintf(&b, "; Max-Age=%d", c.MaxAge)
+	} else if c.MaxAge < 0 {
+		fmt.Fprintf(&b, "; Max-Age=0")
+	}
+	if c.HttpOnly {
+		fmt.Fprintf(&b, "; HttpOnly")
+	}
+	if c.Secure {
+		fmt.Fprintf(&b, "; Secure")
+	}
+	return b.String()
+}
+
+// readCookies parses all "Cookie" values from the header h and
+// returns the successfully parsed Cookies.
+//
+// if filter isn't empty, only cookies of that name are returned
+func readCookies(h Header, filter string) []*Cookie {
+	cookies := []*Cookie{}
+	lines, ok := h["Cookie"]
+	if !ok {
+		return cookies
+	}
+
+	for _, line := range lines {
+		parts := strings.Split(strings.TrimSpace(line), ";")
+		if len(parts) == 1 && parts[0] == "" {
+			continue
+		}
+		// Per-line attributes
+		parsedPairs := 0
+		for i := 0; i < len(parts); i++ {
+			parts[i] = strings.TrimSpace(parts[i])
+			if len(parts[i]) == 0 {
+				continue
+			}
+			name, val := parts[i], ""
+			if j := strings.Index(name, "="); j >= 0 {
+				name, val = name[:j], name[j+1:]
+			}
+			if !isCookieNameValid(name) {
+				continue
+			}
+			if filter != "" && filter != name {
+				continue
+			}
+			val, success := parseCookieValue(val)
+			if !success {
+				continue
+			}
+			cookies = append(cookies, &Cookie{Name: name, Value: val})
+			parsedPairs++
+		}
+	}
+	return cookies
+}
+
+// validCookieDomain returns wheter v is a valid cookie domain-value.
+func validCookieDomain(v string) bool {
+	if isCookieDomainName(v) {
+		return true
+	}
+	if net.ParseIP(v) != nil && !strings.Contains(v, ":") {
+		return true
+	}
+	return false
+}
+
+// isCookieDomainName returns whether s is a valid domain name or a valid
+// domain name with a leading dot '.'.  It is almost a direct copy of
+// package net's isDomainName.
+func isCookieDomainName(s string) bool {
+	if len(s) == 0 {
+		return false
+	}
+	if len(s) > 255 {
+		return false
+	}
+
+	if s[0] == '.' {
+		// A cookie a domain attribute may start with a leading dot.
+		s = s[1:]
+	}
+	last := byte('.')
+	ok := false // Ok once we've seen a letter.
+	partlen := 0
+	for i := 0; i < len(s); i++ {
+		c := s[i]
+		switch {
+		default:
+			return false
+		case 'a' <= c && c <= 'z' || 'A' <= c && c <= 'Z':
+			// No '_' allowed here (in contrast to package net).
+			ok = true
+			partlen++
+		case '0' <= c && c <= '9':
+			// fine
+			partlen++
+		case c == '-':
+			// Byte before dash cannot be dot.
+			if last == '.' {
+				return false
+			}
+			partlen++
+		case c == '.':
+			// Byte before dot cannot be dot, dash.
+			if last == '.' || last == '-' {
+				return false
+			}
+			if partlen > 63 || partlen == 0 {
+				return false
+			}
+			partlen = 0
+		}
+		last = c
+	}
+	if last == '-' || partlen > 63 {
+		return false
+	}
+
+	return ok
+}
+
+var cookieNameSanitizer = strings.NewReplacer("\n", "-", "\r", "-")
+
+func sanitizeCookieName(n string) string {
+	return cookieNameSanitizer.Replace(n)
+}
+
+// http://tools.ietf.org/html/rfc6265#section-4.1.1
+// cookie-value      = *cookie-octet / ( DQUOTE *cookie-octet DQUOTE )
+// cookie-octet      = %x21 / %x23-2B / %x2D-3A / %x3C-5B / %x5D-7E
+//           ; US-ASCII characters excluding CTLs,
+//           ; whitespace DQUOTE, comma, semicolon,
+//           ; and backslash
+// We loosen this as spaces and commas are common in cookie values
+// but we produce a quoted cookie-value in when value starts or ends
+// with a comma or space.
+// See http://golang.org/issue/7243 for the discussion.
+func sanitizeCookieValue(v string) string {
+	v = sanitizeOrWarn("Cookie.Value", validCookieValueByte, v)
+	if len(v) == 0 {
+		return v
+	}
+	if v[0] == ' ' || v[0] == ',' || v[len(v)-1] == ' ' || v[len(v)-1] == ',' {
+		return `"` + v + `"`
+	}
+	return v
+}
+
+func validCookieValueByte(b byte) bool {
+	return 0x20 <= b && b < 0x7f && b != '"' && b != ';' && b != '\\'
+}
+
+// path-av           = "Path=" path-value
+// path-value        = <any CHAR except CTLs or ";">
+func sanitizeCookiePath(v string) string {
+	return sanitizeOrWarn("Cookie.Path", validCookiePathByte, v)
+}
+
+func validCookiePathByte(b byte) bool {
+	return 0x20 <= b && b < 0x7f && b != ';'
+}
+
+func sanitizeOrWarn(fieldName string, valid func(byte) bool, v string) string {
+	ok := true
+	for i := 0; i < len(v); i++ {
+		if valid(v[i]) {
+			continue
+		}
+		log.Printf("net/http: invalid byte %q in %s; dropping invalid bytes", v[i], fieldName)
+		ok = false
+		break
+	}
+	if ok {
+		return v
+	}
+	buf := make([]byte, 0, len(v))
+	for i := 0; i < len(v); i++ {
+		if b := v[i]; valid(b) {
+			buf = append(buf, b)
+		}
+	}
+	return string(buf)
+}
+
+func parseCookieValue(raw string) (string, bool) {
+	// Strip the quotes, if present.
+	if len(raw) > 1 && raw[0] == '"' && raw[len(raw)-1] == '"' {
+		raw = raw[1 : len(raw)-1]
+	}
+	for i := 0; i < len(raw); i++ {
+		if !validCookieValueByte(raw[i]) {
+			return "", false
+		}
+	}
+	return raw, true
+}
+
+func isCookieNameValid(raw string) bool {
+	return strings.IndexFunc(raw, isNotToken) < 0
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/http/doc.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/doc.go
new file mode 100644
index 000000000..b1216e8da
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/doc.go
@@ -0,0 +1,80 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+Package http provides HTTP client and server implementations.
+
+Get, Head, Post, and PostForm make HTTP (or HTTPS) requests:
+
+	resp, err := http.Get("http://example.com/")
+	...
+	resp, err := http.Post("http://example.com/upload", "image/jpeg", &buf)
+	...
+	resp, err := http.PostForm("http://example.com/form",
+		url.Values{"key": {"Value"}, "id": {"123"}})
+
+The client must close the response body when finished with it:
+
+	resp, err := http.Get("http://example.com/")
+	if err != nil {
+		// handle error
+	}
+	defer resp.Body.Close()
+	body, err := ioutil.ReadAll(resp.Body)
+	// ...
+
+For control over HTTP client headers, redirect policy, and other
+settings, create a Client:
+
+	client := &http.Client{
+		CheckRedirect: redirectPolicyFunc,
+	}
+
+	resp, err := client.Get("http://example.com")
+	// ...
+
+	req, err := http.NewRequest("GET", "http://example.com", nil)
+	// ...
+	req.Header.Add("If-None-Match", `W/"wyzzy"`)
+	resp, err := client.Do(req)
+	// ...
+
+For control over proxies, TLS configuration, keep-alives,
+compression, and other settings, create a Transport:
+
+	tr := &http.Transport{
+		TLSClientConfig:    &tls.Config{RootCAs: pool},
+		DisableCompression: true,
+	}
+	client := &http.Client{Transport: tr}
+	resp, err := client.Get("https://example.com")
+
+Clients and Transports are safe for concurrent use by multiple
+goroutines and for efficiency should only be created once and re-used.
+
+ListenAndServe starts an HTTP server with a given address and handler.
+The handler is usually nil, which means to use DefaultServeMux.
+Handle and HandleFunc add handlers to DefaultServeMux:
+
+	http.Handle("/foo", fooHandler)
+
+	http.HandleFunc("/bar", func(w http.ResponseWriter, r *http.Request) {
+		fmt.Fprintf(w, "Hello, %q", html.EscapeString(r.URL.Path))
+	})
+
+	log.Fatal(http.ListenAndServe(":8080", nil))
+
+More control over the server's behavior is available by creating a
+custom Server:
+
+	s := &http.Server{
+		Addr:           ":8080",
+		Handler:        myHandler,
+		ReadTimeout:    10 * time.Second,
+		WriteTimeout:   10 * time.Second,
+		MaxHeaderBytes: 1 << 20,
+	}
+	log.Fatal(s.ListenAndServe())
+*/
+package http
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/http/filetransport.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/filetransport.go
new file mode 100644
index 000000000..821787e0c
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/filetransport.go
@@ -0,0 +1,123 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package http
+
+import (
+	"fmt"
+	"io"
+)
+
+// fileTransport implements RoundTripper for the 'file' protocol.
+type fileTransport struct {
+	fh fileHandler
+}
+
+// NewFileTransport returns a new RoundTripper, serving the provided
+// FileSystem. The returned RoundTripper ignores the URL host in its
+// incoming requests, as well as most other properties of the
+// request.
+//
+// The typical use case for NewFileTransport is to register the "file"
+// protocol with a Transport, as in:
+//
+//   t := &http.Transport{}
+//   t.RegisterProtocol("file", http.NewFileTransport(http.Dir("/")))
+//   c := &http.Client{Transport: t}
+//   res, err := c.Get("file:///etc/passwd")
+//   ...
+func NewFileTransport(fs FileSystem) RoundTripper {
+	return fileTransport{fileHandler{fs}}
+}
+
+func (t fileTransport) RoundTrip(req *Request) (resp *Response, err error) {
+	// We start ServeHTTP in a goroutine, which may take a long
+	// time if the file is large.  The newPopulateResponseWriter
+	// call returns a channel which either ServeHTTP or finish()
+	// sends our *Response on, once the *Response itself has been
+	// populated (even if the body itself is still being
+	// written to the res.Body, a pipe)
+	rw, resc := newPopulateResponseWriter()
+	go func() {
+		t.fh.ServeHTTP(rw, req)
+		rw.finish()
+	}()
+	return <-resc, nil
+}
+
+func newPopulateResponseWriter() (*populateResponse, <-chan *Response) {
+	pr, pw := io.Pipe()
+	rw := &populateResponse{
+		ch: make(chan *Response),
+		pw: pw,
+		res: &Response{
+			Proto:      "HTTP/1.0",
+			ProtoMajor: 1,
+			Header:     make(Header),
+			Close:      true,
+			Body:       pr,
+		},
+	}
+	return rw, rw.ch
+}
+
+// populateResponse is a ResponseWriter that populates the *Response
+// in res, and writes its body to a pipe connected to the response
+// body. Once writes begin or finish() is called, the response is sent
+// on ch.
+type populateResponse struct {
+	res          *Response
+	ch           chan *Response
+	wroteHeader  bool
+	hasContent   bool
+	sentResponse bool
+	pw           *io.PipeWriter
+}
+
+func (pr *populateResponse) finish() {
+	if !pr.wroteHeader {
+		pr.WriteHeader(500)
+	}
+	if !pr.sentResponse {
+		pr.sendResponse()
+	}
+	pr.pw.Close()
+}
+
+func (pr *populateResponse) sendResponse() {
+	if pr.sentResponse {
+		return
+	}
+	pr.sentResponse = true
+
+	if pr.hasContent {
+		pr.res.ContentLength = -1
+	}
+	pr.ch <- pr.res
+}
+
+func (pr *populateResponse) Header() Header {
+	return pr.res.Header
+}
+
+func (pr *populateResponse) WriteHeader(code int) {
+	if pr.wroteHeader {
+		return
+	}
+	pr.wroteHeader = true
+
+	pr.res.StatusCode = code
+	pr.res.Status = fmt.Sprintf("%d %s", code, StatusText(code))
+}
+
+func (pr *populateResponse) Write(p []byte) (n int, err error) {
+	if !pr.wroteHeader {
+		pr.WriteHeader(StatusOK)
+	}
+	pr.hasContent = true
+	if !pr.sentResponse {
+		pr.sendResponse()
+	}
+	return pr.pw.Write(p)
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/http/fs.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/fs.go
new file mode 100644
index 000000000..8576cf844
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/fs.go
@@ -0,0 +1,549 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// HTTP file system request handler
+
+package http
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"mime"
+	"mime/multipart"
+	"net/textproto"
+	"net/url"
+	"os"
+	"path"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// A Dir implements http.FileSystem using the native file
+// system restricted to a specific directory tree.
+//
+// An empty Dir is treated as ".".
+type Dir string
+
+func (d Dir) Open(name string) (File, error) {
+	if filepath.Separator != '/' && strings.IndexRune(name, filepath.Separator) >= 0 ||
+		strings.Contains(name, "\x00") {
+		return nil, errors.New("http: invalid character in file path")
+	}
+	dir := string(d)
+	if dir == "" {
+		dir = "."
+	}
+	f, err := os.Open(filepath.Join(dir, filepath.FromSlash(path.Clean("/"+name))))
+	if err != nil {
+		return nil, err
+	}
+	return f, nil
+}
+
+// A FileSystem implements access to a collection of named files.
+// The elements in a file path are separated by slash ('/', U+002F)
+// characters, regardless of host operating system convention.
+type FileSystem interface {
+	Open(name string) (File, error)
+}
+
+// A File is returned by a FileSystem's Open method and can be
+// served by the FileServer implementation.
+//
+// The methods should behave the same as those on an *os.File.
+type File interface {
+	io.Closer
+	io.Reader
+	Readdir(count int) ([]os.FileInfo, error)
+	Seek(offset int64, whence int) (int64, error)
+	Stat() (os.FileInfo, error)
+}
+
+func dirList(w ResponseWriter, f File) {
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	fmt.Fprintf(w, "<pre>\n")
+	for {
+		dirs, err := f.Readdir(100)
+		if err != nil || len(dirs) == 0 {
+			break
+		}
+		for _, d := range dirs {
+			name := d.Name()
+			if d.IsDir() {
+				name += "/"
+			}
+			// name may contain '?' or '#', which must be escaped to remain
+			// part of the URL path, and not indicate the start of a query
+			// string or fragment.
+			url := url.URL{Path: name}
+			fmt.Fprintf(w, "<a href=\"%s\">%s</a>\n", url.String(), htmlReplacer.Replace(name))
+		}
+	}
+	fmt.Fprintf(w, "</pre>\n")
+}
+
+// ServeContent replies to the request using the content in the
+// provided ReadSeeker.  The main benefit of ServeContent over io.Copy
+// is that it handles Range requests properly, sets the MIME type, and
+// handles If-Modified-Since requests.
+//
+// If the response's Content-Type header is not set, ServeContent
+// first tries to deduce the type from name's file extension and,
+// if that fails, falls back to reading the first block of the content
+// and passing it to DetectContentType.
+// The name is otherwise unused; in particular it can be empty and is
+// never sent in the response.
+//
+// If modtime is not the zero time, ServeContent includes it in a
+// Last-Modified header in the response.  If the request includes an
+// If-Modified-Since header, ServeContent uses modtime to decide
+// whether the content needs to be sent at all.
+//
+// The content's Seek method must work: ServeContent uses
+// a seek to the end of the content to determine its size.
+//
+// If the caller has set w's ETag header, ServeContent uses it to
+// handle requests using If-Range and If-None-Match.
+//
+// Note that *os.File implements the io.ReadSeeker interface.
+func ServeContent(w ResponseWriter, req *Request, name string, modtime time.Time, content io.ReadSeeker) {
+	sizeFunc := func() (int64, error) {
+		size, err := content.Seek(0, os.SEEK_END)
+		if err != nil {
+			return 0, errSeeker
+		}
+		_, err = content.Seek(0, os.SEEK_SET)
+		if err != nil {
+			return 0, errSeeker
+		}
+		return size, nil
+	}
+	serveContent(w, req, name, modtime, sizeFunc, content)
+}
+
+// errSeeker is returned by ServeContent's sizeFunc when the content
+// doesn't seek properly. The underlying Seeker's error text isn't
+// included in the sizeFunc reply so it's not sent over HTTP to end
+// users.
+var errSeeker = errors.New("seeker can't seek")
+
+// if name is empty, filename is unknown. (used for mime type, before sniffing)
+// if modtime.IsZero(), modtime is unknown.
+// content must be seeked to the beginning of the file.
+// The sizeFunc is called at most once. Its error, if any, is sent in the HTTP response.
+func serveContent(w ResponseWriter, r *Request, name string, modtime time.Time, sizeFunc func() (int64, error), content io.ReadSeeker) {
+	if checkLastModified(w, r, modtime) {
+		return
+	}
+	rangeReq, done := checkETag(w, r)
+	if done {
+		return
+	}
+
+	code := StatusOK
+
+	// If Content-Type isn't set, use the file's extension to find it, but
+	// if the Content-Type is unset explicitly, do not sniff the type.
+	ctypes, haveType := w.Header()["Content-Type"]
+	var ctype string
+	if !haveType {
+		ctype = mime.TypeByExtension(filepath.Ext(name))
+		if ctype == "" {
+			// read a chunk to decide between utf-8 text and binary
+			var buf [sniffLen]byte
+			n, _ := io.ReadFull(content, buf[:])
+			ctype = DetectContentType(buf[:n])
+			_, err := content.Seek(0, os.SEEK_SET) // rewind to output whole file
+			if err != nil {
+				Error(w, "seeker can't seek", StatusInternalServerError)
+				return
+			}
+		}
+		w.Header().Set("Content-Type", ctype)
+	} else if len(ctypes) > 0 {
+		ctype = ctypes[0]
+	}
+
+	size, err := sizeFunc()
+	if err != nil {
+		Error(w, err.Error(), StatusInternalServerError)
+		return
+	}
+
+	// handle Content-Range header.
+	sendSize := size
+	var sendContent io.Reader = content
+	if size >= 0 {
+		ranges, err := parseRange(rangeReq, size)
+		if err != nil {
+			Error(w, err.Error(), StatusRequestedRangeNotSatisfiable)
+			return
+		}
+		if sumRangesSize(ranges) > size {
+			// The total number of bytes in all the ranges
+			// is larger than the size of the file by
+			// itself, so this is probably an attack, or a
+			// dumb client.  Ignore the range request.
+			ranges = nil
+		}
+		switch {
+		case len(ranges) == 1:
+			// RFC 2616, Section 14.16:
+			// "When an HTTP message includes the content of a single
+			// range (for example, a response to a request for a
+			// single range, or to a request for a set of ranges
+			// that overlap without any holes), this content is
+			// transmitted with a Content-Range header, and a
+			// Content-Length header showing the number of bytes
+			// actually transferred.
+			// ...
+			// A response to a request for a single range MUST NOT
+			// be sent using the multipart/byteranges media type."
+			ra := ranges[0]
+			if _, err := content.Seek(ra.start, os.SEEK_SET); err != nil {
+				Error(w, err.Error(), StatusRequestedRangeNotSatisfiable)
+				return
+			}
+			sendSize = ra.length
+			code = StatusPartialContent
+			w.Header().Set("Content-Range", ra.contentRange(size))
+		case len(ranges) > 1:
+			for _, ra := range ranges {
+				if ra.start > size {
+					Error(w, err.Error(), StatusRequestedRangeNotSatisfiable)
+					return
+				}
+			}
+			sendSize = rangesMIMESize(ranges, ctype, size)
+			code = StatusPartialContent
+
+			pr, pw := io.Pipe()
+			mw := multipart.NewWriter(pw)
+			w.Header().Set("Content-Type", "multipart/byteranges; boundary="+mw.Boundary())
+			sendContent = pr
+			defer pr.Close() // cause writing goroutine to fail and exit if CopyN doesn't finish.
+			go func() {
+				for _, ra := range ranges {
+					part, err := mw.CreatePart(ra.mimeHeader(ctype, size))
+					if err != nil {
+						pw.CloseWithError(err)
+						return
+					}
+					if _, err := content.Seek(ra.start, os.SEEK_SET); err != nil {
+						pw.CloseWithError(err)
+						return
+					}
+					if _, err := io.CopyN(part, content, ra.length); err != nil {
+						pw.CloseWithError(err)
+						return
+					}
+				}
+				mw.Close()
+				pw.Close()
+			}()
+		}
+
+		w.Header().Set("Accept-Ranges", "bytes")
+		if w.Header().Get("Content-Encoding") == "" {
+			w.Header().Set("Content-Length", strconv.FormatInt(sendSize, 10))
+		}
+	}
+
+	w.WriteHeader(code)
+
+	if r.Method != "HEAD" {
+		io.CopyN(w, sendContent, sendSize)
+	}
+}
+
+// modtime is the modification time of the resource to be served, or IsZero().
+// return value is whether this request is now complete.
+func checkLastModified(w ResponseWriter, r *Request, modtime time.Time) bool {
+	if modtime.IsZero() {
+		return false
+	}
+
+	// The Date-Modified header truncates sub-second precision, so
+	// use mtime < t+1s instead of mtime <= t to check for unmodified.
+	if t, err := time.Parse(TimeFormat, r.Header.Get("If-Modified-Since")); err == nil && modtime.Before(t.Add(1*time.Second)) {
+		h := w.Header()
+		delete(h, "Content-Type")
+		delete(h, "Content-Length")
+		w.WriteHeader(StatusNotModified)
+		return true
+	}
+	w.Header().Set("Last-Modified", modtime.UTC().Format(TimeFormat))
+	return false
+}
+
+// checkETag implements If-None-Match and If-Range checks.
+// The ETag must have been previously set in the ResponseWriter's headers.
+//
+// The return value is the effective request "Range" header to use and
+// whether this request is now considered done.
+func checkETag(w ResponseWriter, r *Request) (rangeReq string, done bool) {
+	etag := w.Header().get("Etag")
+	rangeReq = r.Header.get("Range")
+
+	// Invalidate the range request if the entity doesn't match the one
+	// the client was expecting.
+	// "If-Range: version" means "ignore the Range: header unless version matches the
+	// current file."
+	// We only support ETag versions.
+	// The caller must have set the ETag on the response already.
+	if ir := r.Header.get("If-Range"); ir != "" && ir != etag {
+		// TODO(bradfitz): handle If-Range requests with Last-Modified
+		// times instead of ETags? I'd rather not, at least for
+		// now. That seems like a bug/compromise in the RFC 2616, and
+		// I've never heard of anybody caring about that (yet).
+		rangeReq = ""
+	}
+
+	if inm := r.Header.get("If-None-Match"); inm != "" {
+		// Must know ETag.
+		if etag == "" {
+			return rangeReq, false
+		}
+
+		// TODO(bradfitz): non-GET/HEAD requests require more work:
+		// sending a different status code on matches, and
+		// also can't use weak cache validators (those with a "W/
+		// prefix).  But most users of ServeContent will be using
+		// it on GET or HEAD, so only support those for now.
+		if r.Method != "GET" && r.Method != "HEAD" {
+			return rangeReq, false
+		}
+
+		// TODO(bradfitz): deal with comma-separated or multiple-valued
+		// list of If-None-match values.  For now just handle the common
+		// case of a single item.
+		if inm == etag || inm == "*" {
+			h := w.Header()
+			delete(h, "Content-Type")
+			delete(h, "Content-Length")
+			w.WriteHeader(StatusNotModified)
+			return "", true
+		}
+	}
+	return rangeReq, false
+}
+
+// name is '/'-separated, not filepath.Separator.
+func serveFile(w ResponseWriter, r *Request, fs FileSystem, name string, redirect bool) {
+	const indexPage = "/index.html"
+
+	// redirect .../index.html to .../
+	// can't use Redirect() because that would make the path absolute,
+	// which would be a problem running under StripPrefix
+	if strings.HasSuffix(r.URL.Path, indexPage) {
+		localRedirect(w, r, "./")
+		return
+	}
+
+	f, err := fs.Open(name)
+	if err != nil {
+		// TODO expose actual error?
+		NotFound(w, r)
+		return
+	}
+	defer f.Close()
+
+	d, err1 := f.Stat()
+	if err1 != nil {
+		// TODO expose actual error?
+		NotFound(w, r)
+		return
+	}
+
+	if redirect {
+		// redirect to canonical path: / at end of directory url
+		// r.URL.Path always begins with /
+		url := r.URL.Path
+		if d.IsDir() {
+			if url[len(url)-1] != '/' {
+				localRedirect(w, r, path.Base(url)+"/")
+				return
+			}
+		} else {
+			if url[len(url)-1] == '/' {
+				localRedirect(w, r, "../"+path.Base(url))
+				return
+			}
+		}
+	}
+
+	// use contents of index.html for directory, if present
+	if d.IsDir() {
+		index := name + indexPage
+		ff, err := fs.Open(index)
+		if err == nil {
+			defer ff.Close()
+			dd, err := ff.Stat()
+			if err == nil {
+				name = index
+				d = dd
+				f = ff
+			}
+		}
+	}
+
+	// Still a directory? (we didn't find an index.html file)
+	if d.IsDir() {
+		if checkLastModified(w, r, d.ModTime()) {
+			return
+		}
+		dirList(w, f)
+		return
+	}
+
+	// serverContent will check modification time
+	sizeFunc := func() (int64, error) { return d.Size(), nil }
+	serveContent(w, r, d.Name(), d.ModTime(), sizeFunc, f)
+}
+
+// localRedirect gives a Moved Permanently response.
+// It does not convert relative paths to absolute paths like Redirect does.
+func localRedirect(w ResponseWriter, r *Request, newPath string) {
+	if q := r.URL.RawQuery; q != "" {
+		newPath += "?" + q
+	}
+	w.Header().Set("Location", newPath)
+	w.WriteHeader(StatusMovedPermanently)
+}
+
+// ServeFile replies to the request with the contents of the named file or directory.
+func ServeFile(w ResponseWriter, r *Request, name string) {
+	dir, file := filepath.Split(name)
+	serveFile(w, r, Dir(dir), file, false)
+}
+
+type fileHandler struct {
+	root FileSystem
+}
+
+// FileServer returns a handler that serves HTTP requests
+// with the contents of the file system rooted at root.
+//
+// To use the operating system's file system implementation,
+// use http.Dir:
+//
+//     http.Handle("/", http.FileServer(http.Dir("/tmp")))
+func FileServer(root FileSystem) Handler {
+	return &fileHandler{root}
+}
+
+func (f *fileHandler) ServeHTTP(w ResponseWriter, r *Request) {
+	upath := r.URL.Path
+	if !strings.HasPrefix(upath, "/") {
+		upath = "/" + upath
+		r.URL.Path = upath
+	}
+	serveFile(w, r, f.root, path.Clean(upath), true)
+}
+
+// httpRange specifies the byte range to be sent to the client.
+type httpRange struct {
+	start, length int64
+}
+
+func (r httpRange) contentRange(size int64) string {
+	return fmt.Sprintf("bytes %d-%d/%d", r.start, r.start+r.length-1, size)
+}
+
+func (r httpRange) mimeHeader(contentType string, size int64) textproto.MIMEHeader {
+	return textproto.MIMEHeader{
+		"Content-Range": {r.contentRange(size)},
+		"Content-Type":  {contentType},
+	}
+}
+
+// parseRange parses a Range header string as per RFC 2616.
+func parseRange(s string, size int64) ([]httpRange, error) {
+	if s == "" {
+		return nil, nil // header not present
+	}
+	const b = "bytes="
+	if !strings.HasPrefix(s, b) {
+		return nil, errors.New("invalid range")
+	}
+	var ranges []httpRange
+	for _, ra := range strings.Split(s[len(b):], ",") {
+		ra = strings.TrimSpace(ra)
+		if ra == "" {
+			continue
+		}
+		i := strings.Index(ra, "-")
+		if i < 0 {
+			return nil, errors.New("invalid range")
+		}
+		start, end := strings.TrimSpace(ra[:i]), strings.TrimSpace(ra[i+1:])
+		var r httpRange
+		if start == "" {
+			// If no start is specified, end specifies the
+			// range start relative to the end of the file.
+			i, err := strconv.ParseInt(end, 10, 64)
+			if err != nil {
+				return nil, errors.New("invalid range")
+			}
+			if i > size {
+				i = size
+			}
+			r.start = size - i
+			r.length = size - r.start
+		} else {
+			i, err := strconv.ParseInt(start, 10, 64)
+			if err != nil || i > size || i < 0 {
+				return nil, errors.New("invalid range")
+			}
+			r.start = i
+			if end == "" {
+				// If no end is specified, range extends to end of the file.
+				r.length = size - r.start
+			} else {
+				i, err := strconv.ParseInt(end, 10, 64)
+				if err != nil || r.start > i {
+					return nil, errors.New("invalid range")
+				}
+				if i >= size {
+					i = size - 1
+				}
+				r.length = i - r.start + 1
+			}
+		}
+		ranges = append(ranges, r)
+	}
+	return ranges, nil
+}
+
+// countingWriter counts how many bytes have been written to it.
+type countingWriter int64
+
+func (w *countingWriter) Write(p []byte) (n int, err error) {
+	*w += countingWriter(len(p))
+	return len(p), nil
+}
+
+// rangesMIMESize returns the number of bytes it takes to encode the
+// provided ranges as a multipart response.
+func rangesMIMESize(ranges []httpRange, contentType string, contentSize int64) (encSize int64) {
+	var w countingWriter
+	mw := multipart.NewWriter(&w)
+	for _, ra := range ranges {
+		mw.CreatePart(ra.mimeHeader(contentType, contentSize))
+		encSize += ra.length
+	}
+	mw.Close()
+	encSize += int64(w)
+	return
+}
+
+func sumRangesSize(ranges []httpRange) (size int64) {
+	for _, ra := range ranges {
+		size += ra.length
+	}
+	return
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/http/header.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/header.go
new file mode 100644
index 000000000..153b94370
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/header.go
@@ -0,0 +1,211 @@
+// Copyright 2010 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package http
+
+import (
+	"io"
+	"net/textproto"
+	"sort"
+	"strings"
+	"sync"
+	"time"
+)
+
+var raceEnabled = false // set by race.go
+
+// A Header represents the key-value pairs in an HTTP header.
+type Header map[string][]string
+
+// Add adds the key, value pair to the header.
+// It appends to any existing values associated with key.
+func (h Header) Add(key, value string) {
+	textproto.MIMEHeader(h).Add(key, value)
+}
+
+// Set sets the header entries associated with key to
+// the single element value.  It replaces any existing
+// values associated with key.
+func (h Header) Set(key, value string) {
+	textproto.MIMEHeader(h).Set(key, value)
+}
+
+// Get gets the first value associated with the given key.
+// If there are no values associated with the key, Get returns "".
+// To access multiple values of a key, access the map directly
+// with CanonicalHeaderKey.
+func (h Header) Get(key string) string {
+	return textproto.MIMEHeader(h).Get(key)
+}
+
+// get is like Get, but key must already be in CanonicalHeaderKey form.
+func (h Header) get(key string) string {
+	if v := h[key]; len(v) > 0 {
+		return v[0]
+	}
+	return ""
+}
+
+// Del deletes the values associated with key.
+func (h Header) Del(key string) {
+	textproto.MIMEHeader(h).Del(key)
+}
+
+// Write writes a header in wire format.
+func (h Header) Write(w io.Writer) error {
+	return h.WriteSubset(w, nil)
+}
+
+func (h Header) clone() Header {
+	h2 := make(Header, len(h))
+	for k, vv := range h {
+		vv2 := make([]string, len(vv))
+		copy(vv2, vv)
+		h2[k] = vv2
+	}
+	return h2
+}
+
+var timeFormats = []string{
+	TimeFormat,
+	time.RFC850,
+	time.ANSIC,
+}
+
+// ParseTime parses a time header (such as the Date: header),
+// trying each of the three formats allowed by HTTP/1.1:
+// TimeFormat, time.RFC850, and time.ANSIC.
+func ParseTime(text string) (t time.Time, err error) {
+	for _, layout := range timeFormats {
+		t, err = time.Parse(layout, text)
+		if err == nil {
+			return
+		}
+	}
+	return
+}
+
+var headerNewlineToSpace = strings.NewReplacer("\n", " ", "\r", " ")
+
+type writeStringer interface {
+	WriteString(string) (int, error)
+}
+
+// stringWriter implements WriteString on a Writer.
+type stringWriter struct {
+	w io.Writer
+}
+
+func (w stringWriter) WriteString(s string) (n int, err error) {
+	return w.w.Write([]byte(s))
+}
+
+type keyValues struct {
+	key    string
+	values []string
+}
+
+// A headerSorter implements sort.Interface by sorting a []keyValues
+// by key. It's used as a pointer, so it can fit in a sort.Interface
+// interface value without allocation.
+type headerSorter struct {
+	kvs []keyValues
+}
+
+func (s *headerSorter) Len() int           { return len(s.kvs) }
+func (s *headerSorter) Swap(i, j int)      { s.kvs[i], s.kvs[j] = s.kvs[j], s.kvs[i] }
+func (s *headerSorter) Less(i, j int) bool { return s.kvs[i].key < s.kvs[j].key }
+
+var headerSorterPool = sync.Pool{
+	New: func() interface{} { return new(headerSorter) },
+}
+
+// sortedKeyValues returns h's keys sorted in the returned kvs
+// slice. The headerSorter used to sort is also returned, for possible
+// return to headerSorterCache.
+func (h Header) sortedKeyValues(exclude map[string]bool) (kvs []keyValues, hs *headerSorter) {
+	hs = headerSorterPool.Get().(*headerSorter)
+	if cap(hs.kvs) < len(h) {
+		hs.kvs = make([]keyValues, 0, len(h))
+	}
+	kvs = hs.kvs[:0]
+	for k, vv := range h {
+		if !exclude[k] {
+			kvs = append(kvs, keyValues{k, vv})
+		}
+	}
+	hs.kvs = kvs
+	sort.Sort(hs)
+	return kvs, hs
+}
+
+// WriteSubset writes a header in wire format.
+// If exclude is not nil, keys where exclude[key] == true are not written.
+func (h Header) WriteSubset(w io.Writer, exclude map[string]bool) error {
+	ws, ok := w.(writeStringer)
+	if !ok {
+		ws = stringWriter{w}
+	}
+	kvs, sorter := h.sortedKeyValues(exclude)
+	for _, kv := range kvs {
+		for _, v := range kv.values {
+			v = headerNewlineToSpace.Replace(v)
+			v = textproto.TrimString(v)
+			for _, s := range []string{kv.key, ": ", v, "\r\n"} {
+				if _, err := ws.WriteString(s); err != nil {
+					return err
+				}
+			}
+		}
+	}
+	headerSorterPool.Put(sorter)
+	return nil
+}
+
+// CanonicalHeaderKey returns the canonical format of the
+// header key s.  The canonicalization converts the first
+// letter and any letter following a hyphen to upper case;
+// the rest are converted to lowercase.  For example, the
+// canonical key for "accept-encoding" is "Accept-Encoding".
+func CanonicalHeaderKey(s string) string { return textproto.CanonicalMIMEHeaderKey(s) }
+
+// hasToken reports whether token appears with v, ASCII
+// case-insensitive, with space or comma boundaries.
+// token must be all lowercase.
+// v may contain mixed cased.
+func hasToken(v, token string) bool {
+	if len(token) > len(v) || token == "" {
+		return false
+	}
+	if v == token {
+		return true
+	}
+	for sp := 0; sp <= len(v)-len(token); sp++ {
+		// Check that first character is good.
+		// The token is ASCII, so checking only a single byte
+		// is sufficient.  We skip this potential starting
+		// position if both the first byte and its potential
+		// ASCII uppercase equivalent (b|0x20) don't match.
+		// False positives ('^' => '~') are caught by EqualFold.
+		if b := v[sp]; b != token[0] && b|0x20 != token[0] {
+			continue
+		}
+		// Check that start pos is on a valid token boundary.
+		if sp > 0 && !isTokenBoundary(v[sp-1]) {
+			continue
+		}
+		// Check that end pos is on a valid token boundary.
+		if endPos := sp + len(token); endPos != len(v) && !isTokenBoundary(v[endPos]) {
+			continue
+		}
+		if strings.EqualFold(v[sp:sp+len(token)], token) {
+			return true
+		}
+	}
+	return false
+}
+
+func isTokenBoundary(b byte) bool {
+	return b == ' ' || b == ',' || b == '\t'
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/http/jar.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/jar.go
new file mode 100644
index 000000000..5c3de0dad
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/jar.go
@@ -0,0 +1,27 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package http
+
+import (
+	"net/url"
+)
+
+// A CookieJar manages storage and use of cookies in HTTP requests.
+//
+// Implementations of CookieJar must be safe for concurrent use by multiple
+// goroutines.
+//
+// The net/http/cookiejar package provides a CookieJar implementation.
+type CookieJar interface {
+	// SetCookies handles the receipt of the cookies in a reply for the
+	// given URL.  It may or may not choose to save the cookies, depending
+	// on the jar's policy and implementation.
+	SetCookies(u *url.URL, cookies []*Cookie)
+
+	// Cookies returns the cookies to send in a request for the given URL.
+	// It is up to the implementation to honor the standard cookie use
+	// restrictions such as in RFC 6265.
+	Cookies(u *url.URL) []*Cookie
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/http/lex.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/lex.go
new file mode 100644
index 000000000..cb33318f4
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/lex.go
@@ -0,0 +1,96 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package http
+
+// This file deals with lexical matters of HTTP
+
+var isTokenTable = [127]bool{
+	'!':  true,
+	'#':  true,
+	'$':  true,
+	'%':  true,
+	'&':  true,
+	'\'': true,
+	'*':  true,
+	'+':  true,
+	'-':  true,
+	'.':  true,
+	'0':  true,
+	'1':  true,
+	'2':  true,
+	'3':  true,
+	'4':  true,
+	'5':  true,
+	'6':  true,
+	'7':  true,
+	'8':  true,
+	'9':  true,
+	'A':  true,
+	'B':  true,
+	'C':  true,
+	'D':  true,
+	'E':  true,
+	'F':  true,
+	'G':  true,
+	'H':  true,
+	'I':  true,
+	'J':  true,
+	'K':  true,
+	'L':  true,
+	'M':  true,
+	'N':  true,
+	'O':  true,
+	'P':  true,
+	'Q':  true,
+	'R':  true,
+	'S':  true,
+	'T':  true,
+	'U':  true,
+	'W':  true,
+	'V':  true,
+	'X':  true,
+	'Y':  true,
+	'Z':  true,
+	'^':  true,
+	'_':  true,
+	'`':  true,
+	'a':  true,
+	'b':  true,
+	'c':  true,
+	'd':  true,
+	'e':  true,
+	'f':  true,
+	'g':  true,
+	'h':  true,
+	'i':  true,
+	'j':  true,
+	'k':  true,
+	'l':  true,
+	'm':  true,
+	'n':  true,
+	'o':  true,
+	'p':  true,
+	'q':  true,
+	'r':  true,
+	's':  true,
+	't':  true,
+	'u':  true,
+	'v':  true,
+	'w':  true,
+	'x':  true,
+	'y':  true,
+	'z':  true,
+	'|':  true,
+	'~':  true,
+}
+
+func isToken(r rune) bool {
+	i := int(r)
+	return i < len(isTokenTable) && isTokenTable[i]
+}
+
+func isNotToken(r rune) bool {
+	return !isToken(r)
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/http/race.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/race.go
new file mode 100644
index 000000000..766503967
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/race.go
@@ -0,0 +1,11 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build race
+
+package http
+
+func init() {
+	raceEnabled = true
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/http/request.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/request.go
new file mode 100644
index 000000000..a67092066
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/request.go
@@ -0,0 +1,875 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// HTTP Request reading and parsing.
+
+package http
+
+import (
+	"bufio"
+	"bytes"
+	"crypto/tls"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"mime"
+	"mime/multipart"
+	"net/textproto"
+	"net/url"
+	"strconv"
+	"strings"
+	"sync"
+)
+
+const (
+	maxValueLength   = 4096
+	maxHeaderLines   = 1024
+	chunkSize        = 4 << 10  // 4 KB chunks
+	defaultMaxMemory = 32 << 20 // 32 MB
+)
+
+// ErrMissingFile is returned by FormFile when the provided file field name
+// is either not present in the request or not a file field.
+var ErrMissingFile = errors.New("http: no such file")
+
+// HTTP request parsing errors.
+type ProtocolError struct {
+	ErrorString string
+}
+
+func (err *ProtocolError) Error() string { return err.ErrorString }
+
+var (
+	ErrHeaderTooLong        = &ProtocolError{"header too long"}
+	ErrShortBody            = &ProtocolError{"entity body too short"}
+	ErrNotSupported         = &ProtocolError{"feature not supported"}
+	ErrUnexpectedTrailer    = &ProtocolError{"trailer header without chunked transfer encoding"}
+	ErrMissingContentLength = &ProtocolError{"missing ContentLength in HEAD response"}
+	ErrNotMultipart         = &ProtocolError{"request Content-Type isn't multipart/form-data"}
+	ErrMissingBoundary      = &ProtocolError{"no multipart boundary param in Content-Type"}
+)
+
+type badStringError struct {
+	what string
+	str  string
+}
+
+func (e *badStringError) Error() string { return fmt.Sprintf("%s %q", e.what, e.str) }
+
+// Headers that Request.Write handles itself and should be skipped.
+var reqWriteExcludeHeader = map[string]bool{
+	"Host":              true, // not in Header map anyway
+	"User-Agent":        true,
+	"Content-Length":    true,
+	"Transfer-Encoding": true,
+	"Trailer":           true,
+}
+
+// A Request represents an HTTP request received by a server
+// or to be sent by a client.
+//
+// The field semantics differ slightly between client and server
+// usage. In addition to the notes on the fields below, see the
+// documentation for Request.Write and RoundTripper.
+type Request struct {
+	// Method specifies the HTTP method (GET, POST, PUT, etc.).
+	// For client requests an empty string means GET.
+	Method string
+
+	// URL specifies either the URI being requested (for server
+	// requests) or the URL to access (for client requests).
+	//
+	// For server requests the URL is parsed from the URI
+	// supplied on the Request-Line as stored in RequestURI.  For
+	// most requests, fields other than Path and RawQuery will be
+	// empty. (See RFC 2616, Section 5.1.2)
+	//
+	// For client requests, the URL's Host specifies the server to
+	// connect to, while the Request's Host field optionally
+	// specifies the Host header value to send in the HTTP
+	// request.
+	URL *url.URL
+
+	// The protocol version for incoming requests.
+	// Client requests always use HTTP/1.1.
+	Proto      string // "HTTP/1.0"
+	ProtoMajor int    // 1
+	ProtoMinor int    // 0
+
+	// A header maps request lines to their values.
+	// If the header says
+	//
+	//	accept-encoding: gzip, deflate
+	//	Accept-Language: en-us
+	//	Connection: keep-alive
+	//
+	// then
+	//
+	//	Header = map[string][]string{
+	//		"Accept-Encoding": {"gzip, deflate"},
+	//		"Accept-Language": {"en-us"},
+	//		"Connection": {"keep-alive"},
+	//	}
+	//
+	// HTTP defines that header names are case-insensitive.
+	// The request parser implements this by canonicalizing the
+	// name, making the first character and any characters
+	// following a hyphen uppercase and the rest lowercase.
+	//
+	// For client requests certain headers are automatically
+	// added and may override values in Header.
+	//
+	// See the documentation for the Request.Write method.
+	Header Header
+
+	// Body is the request's body.
+	//
+	// For client requests a nil body means the request has no
+	// body, such as a GET request. The HTTP Client's Transport
+	// is responsible for calling the Close method.
+	//
+	// For server requests the Request Body is always non-nil
+	// but will return EOF immediately when no body is present.
+	// The Server will close the request body. The ServeHTTP
+	// Handler does not need to.
+	Body io.ReadCloser
+
+	// ContentLength records the length of the associated content.
+	// The value -1 indicates that the length is unknown.
+	// Values >= 0 indicate that the given number of bytes may
+	// be read from Body.
+	// For client requests, a value of 0 means unknown if Body is not nil.
+	ContentLength int64
+
+	// TransferEncoding lists the transfer encodings from outermost to
+	// innermost. An empty list denotes the "identity" encoding.
+	// TransferEncoding can usually be ignored; chunked encoding is
+	// automatically added and removed as necessary when sending and
+	// receiving requests.
+	TransferEncoding []string
+
+	// Close indicates whether to close the connection after
+	// replying to this request (for servers) or after sending
+	// the request (for clients).
+	Close bool
+
+	// For server requests Host specifies the host on which the
+	// URL is sought. Per RFC 2616, this is either the value of
+	// the "Host" header or the host name given in the URL itself.
+	// It may be of the form "host:port".
+	//
+	// For client requests Host optionally overrides the Host
+	// header to send. If empty, the Request.Write method uses
+	// the value of URL.Host.
+	Host string
+
+	// Form contains the parsed form data, including both the URL
+	// field's query parameters and the POST or PUT form data.
+	// This field is only available after ParseForm is called.
+	// The HTTP client ignores Form and uses Body instead.
+	Form url.Values
+
+	// PostForm contains the parsed form data from POST or PUT
+	// body parameters.
+	// This field is only available after ParseForm is called.
+	// The HTTP client ignores PostForm and uses Body instead.
+	PostForm url.Values
+
+	// MultipartForm is the parsed multipart form, including file uploads.
+	// This field is only available after ParseMultipartForm is called.
+	// The HTTP client ignores MultipartForm and uses Body instead.
+	MultipartForm *multipart.Form
+
+	// Trailer specifies additional headers that are sent after the request
+	// body.
+	//
+	// For server requests the Trailer map initially contains only the
+	// trailer keys, with nil values. (The client declares which trailers it
+	// will later send.)  While the handler is reading from Body, it must
+	// not reference Trailer. After reading from Body returns EOF, Trailer
+	// can be read again and will contain non-nil values, if they were sent
+	// by the client.
+	//
+	// For client requests Trailer must be initialized to a map containing
+	// the trailer keys to later send. The values may be nil or their final
+	// values. The ContentLength must be 0 or -1, to send a chunked request.
+	// After the HTTP request is sent the map values can be updated while
+	// the request body is read. Once the body returns EOF, the caller must
+	// not mutate Trailer.
+	//
+	// Few HTTP clients, servers, or proxies support HTTP trailers.
+	Trailer Header
+
+	// RemoteAddr allows HTTP servers and other software to record
+	// the network address that sent the request, usually for
+	// logging. This field is not filled in by ReadRequest and
+	// has no defined format. The HTTP server in this package
+	// sets RemoteAddr to an "IP:port" address before invoking a
+	// handler.
+	// This field is ignored by the HTTP client.
+	RemoteAddr string
+
+	// RequestURI is the unmodified Request-URI of the
+	// Request-Line (RFC 2616, Section 5.1) as sent by the client
+	// to a server. Usually the URL field should be used instead.
+	// It is an error to set this field in an HTTP client request.
+	RequestURI string
+
+	// TLS allows HTTP servers and other software to record
+	// information about the TLS connection on which the request
+	// was received. This field is not filled in by ReadRequest.
+	// The HTTP server in this package sets the field for
+	// TLS-enabled connections before invoking a handler;
+	// otherwise it leaves the field nil.
+	// This field is ignored by the HTTP client.
+	TLS *tls.ConnectionState
+}
+
+// ProtoAtLeast reports whether the HTTP protocol used
+// in the request is at least major.minor.
+func (r *Request) ProtoAtLeast(major, minor int) bool {
+	return r.ProtoMajor > major ||
+		r.ProtoMajor == major && r.ProtoMinor >= minor
+}
+
+// UserAgent returns the client's User-Agent, if sent in the request.
+func (r *Request) UserAgent() string {
+	return r.Header.Get("User-Agent")
+}
+
+// Cookies parses and returns the HTTP cookies sent with the request.
+func (r *Request) Cookies() []*Cookie {
+	return readCookies(r.Header, "")
+}
+
+var ErrNoCookie = errors.New("http: named cookie not present")
+
+// Cookie returns the named cookie provided in the request or
+// ErrNoCookie if not found.
+func (r *Request) Cookie(name string) (*Cookie, error) {
+	for _, c := range readCookies(r.Header, name) {
+		return c, nil
+	}
+	return nil, ErrNoCookie
+}
+
+// AddCookie adds a cookie to the request.  Per RFC 6265 section 5.4,
+// AddCookie does not attach more than one Cookie header field.  That
+// means all cookies, if any, are written into the same line,
+// separated by semicolon.
+func (r *Request) AddCookie(c *Cookie) {
+	s := fmt.Sprintf("%s=%s", sanitizeCookieName(c.Name), sanitizeCookieValue(c.Value))
+	if c := r.Header.Get("Cookie"); c != "" {
+		r.Header.Set("Cookie", c+"; "+s)
+	} else {
+		r.Header.Set("Cookie", s)
+	}
+}
+
+// Referer returns the referring URL, if sent in the request.
+//
+// Referer is misspelled as in the request itself, a mistake from the
+// earliest days of HTTP.  This value can also be fetched from the
+// Header map as Header["Referer"]; the benefit of making it available
+// as a method is that the compiler can diagnose programs that use the
+// alternate (correct English) spelling req.Referrer() but cannot
+// diagnose programs that use Header["Referrer"].
+func (r *Request) Referer() string {
+	return r.Header.Get("Referer")
+}
+
+// multipartByReader is a sentinel value.
+// Its presence in Request.MultipartForm indicates that parsing of the request
+// body has been handed off to a MultipartReader instead of ParseMultipartFrom.
+var multipartByReader = &multipart.Form{
+	Value: make(map[string][]string),
+	File:  make(map[string][]*multipart.FileHeader),
+}
+
+// MultipartReader returns a MIME multipart reader if this is a
+// multipart/form-data POST request, else returns nil and an error.
+// Use this function instead of ParseMultipartForm to
+// process the request body as a stream.
+func (r *Request) MultipartReader() (*multipart.Reader, error) {
+	if r.MultipartForm == multipartByReader {
+		return nil, errors.New("http: MultipartReader called twice")
+	}
+	if r.MultipartForm != nil {
+		return nil, errors.New("http: multipart handled by ParseMultipartForm")
+	}
+	r.MultipartForm = multipartByReader
+	return r.multipartReader()
+}
+
+func (r *Request) multipartReader() (*multipart.Reader, error) {
+	v := r.Header.Get("Content-Type")
+	if v == "" {
+		return nil, ErrNotMultipart
+	}
+	d, params, err := mime.ParseMediaType(v)
+	if err != nil || d != "multipart/form-data" {
+		return nil, ErrNotMultipart
+	}
+	boundary, ok := params["boundary"]
+	if !ok {
+		return nil, ErrMissingBoundary
+	}
+	return multipart.NewReader(r.Body, boundary), nil
+}
+
+// Return value if nonempty, def otherwise.
+func valueOrDefault(value, def string) string {
+	if value != "" {
+		return value
+	}
+	return def
+}
+
+// NOTE: This is not intended to reflect the actual Go version being used.
+// It was changed from "Go http package" to "Go 1.1 package http" at the
+// time of the Go 1.1 release because the former User-Agent had ended up
+// on a blacklist for some intrusion detection systems.
+// See https://codereview.appspot.com/7532043.
+const defaultUserAgent = "Go 1.1 package http"
+
+// Write writes an HTTP/1.1 request -- header and body -- in wire format.
+// This method consults the following fields of the request:
+//	Host
+//	URL
+//	Method (defaults to "GET")
+//	Header
+//	ContentLength
+//	TransferEncoding
+//	Body
+//
+// If Body is present, Content-Length is <= 0 and TransferEncoding
+// hasn't been set to "identity", Write adds "Transfer-Encoding:
+// chunked" to the header. Body is closed after it is sent.
+func (r *Request) Write(w io.Writer) error {
+	return r.write(w, false, nil)
+}
+
+// WriteProxy is like Write but writes the request in the form
+// expected by an HTTP proxy.  In particular, WriteProxy writes the
+// initial Request-URI line of the request with an absolute URI, per
+// section 5.1.2 of RFC 2616, including the scheme and host.
+// In either case, WriteProxy also writes a Host header, using
+// either r.Host or r.URL.Host.
+func (r *Request) WriteProxy(w io.Writer) error {
+	return r.write(w, true, nil)
+}
+
+// extraHeaders may be nil
+func (req *Request) write(w io.Writer, usingProxy bool, extraHeaders Header) error {
+	host := req.Host
+	if host == "" {
+		if req.URL == nil {
+			return errors.New("http: Request.Write on Request with no Host or URL set")
+		}
+		host = req.URL.Host
+	}
+
+	ruri := req.URL.RequestURI()
+	if usingProxy && req.URL.Scheme != "" && req.URL.Opaque == "" {
+		ruri = req.URL.Scheme + "://" + host + ruri
+	} else if req.Method == "CONNECT" && req.URL.Path == "" {
+		// CONNECT requests normally give just the host and port, not a full URL.
+		ruri = host
+	}
+	// TODO(bradfitz): escape at least newlines in ruri?
+
+	// Wrap the writer in a bufio Writer if it's not already buffered.
+	// Don't always call NewWriter, as that forces a bytes.Buffer
+	// and other small bufio Writers to have a minimum 4k buffer
+	// size.
+	var bw *bufio.Writer
+	if _, ok := w.(io.ByteWriter); !ok {
+		bw = bufio.NewWriter(w)
+		w = bw
+	}
+
+	fmt.Fprintf(w, "%s %s HTTP/1.1\r\n", valueOrDefault(req.Method, "GET"), ruri)
+
+	// Header lines
+	fmt.Fprintf(w, "Host: %s\r\n", host)
+
+	// Use the defaultUserAgent unless the Header contains one, which
+	// may be blank to not send the header.
+	userAgent := defaultUserAgent
+	if req.Header != nil {
+		if ua := req.Header["User-Agent"]; len(ua) > 0 {
+			userAgent = ua[0]
+		}
+	}
+	if userAgent != "" {
+		fmt.Fprintf(w, "User-Agent: %s\r\n", userAgent)
+	}
+
+	// Process Body,ContentLength,Close,Trailer
+	tw, err := newTransferWriter(req)
+	if err != nil {
+		return err
+	}
+	err = tw.WriteHeader(w)
+	if err != nil {
+		return err
+	}
+
+	err = req.Header.WriteSubset(w, reqWriteExcludeHeader)
+	if err != nil {
+		return err
+	}
+
+	if extraHeaders != nil {
+		err = extraHeaders.Write(w)
+		if err != nil {
+			return err
+		}
+	}
+
+	io.WriteString(w, "\r\n")
+
+	// Write body and trailer
+	err = tw.WriteBody(w)
+	if err != nil {
+		return err
+	}
+
+	if bw != nil {
+		return bw.Flush()
+	}
+	return nil
+}
+
+// ParseHTTPVersion parses a HTTP version string.
+// "HTTP/1.0" returns (1, 0, true).
+func ParseHTTPVersion(vers string) (major, minor int, ok bool) {
+	const Big = 1000000 // arbitrary upper bound
+	switch vers {
+	case "HTTP/1.1":
+		return 1, 1, true
+	case "HTTP/1.0":
+		return 1, 0, true
+	}
+	if !strings.HasPrefix(vers, "HTTP/") {
+		return 0, 0, false
+	}
+	dot := strings.Index(vers, ".")
+	if dot < 0 {
+		return 0, 0, false
+	}
+	major, err := strconv.Atoi(vers[5:dot])
+	if err != nil || major < 0 || major > Big {
+		return 0, 0, false
+	}
+	minor, err = strconv.Atoi(vers[dot+1:])
+	if err != nil || minor < 0 || minor > Big {
+		return 0, 0, false
+	}
+	return major, minor, true
+}
+
+// NewRequest returns a new Request given a method, URL, and optional body.
+//
+// If the provided body is also an io.Closer, the returned
+// Request.Body is set to body and will be closed by the Client
+// methods Do, Post, and PostForm, and Transport.RoundTrip.
+func NewRequest(method, urlStr string, body io.Reader) (*Request, error) {
+	u, err := url.Parse(urlStr)
+	if err != nil {
+		return nil, err
+	}
+	rc, ok := body.(io.ReadCloser)
+	if !ok && body != nil {
+		rc = ioutil.NopCloser(body)
+	}
+	req := &Request{
+		Method:     method,
+		URL:        u,
+		Proto:      "HTTP/1.1",
+		ProtoMajor: 1,
+		ProtoMinor: 1,
+		Header:     make(Header),
+		Body:       rc,
+		Host:       u.Host,
+	}
+	if body != nil {
+		switch v := body.(type) {
+		case *bytes.Buffer:
+			req.ContentLength = int64(v.Len())
+		case *bytes.Reader:
+			req.ContentLength = int64(v.Len())
+		case *strings.Reader:
+			req.ContentLength = int64(v.Len())
+		}
+	}
+
+	return req, nil
+}
+
+// SetBasicAuth sets the request's Authorization header to use HTTP
+// Basic Authentication with the provided username and password.
+//
+// With HTTP Basic Authentication the provided username and password
+// are not encrypted.
+func (r *Request) SetBasicAuth(username, password string) {
+	r.Header.Set("Authorization", "Basic "+basicAuth(username, password))
+}
+
+// parseRequestLine parses "GET /foo HTTP/1.1" into its three parts.
+func parseRequestLine(line string) (method, requestURI, proto string, ok bool) {
+	s1 := strings.Index(line, " ")
+	s2 := strings.Index(line[s1+1:], " ")
+	if s1 < 0 || s2 < 0 {
+		return
+	}
+	s2 += s1 + 1
+	return line[:s1], line[s1+1 : s2], line[s2+1:], true
+}
+
+var textprotoReaderPool sync.Pool
+
+func newTextprotoReader(br *bufio.Reader) *textproto.Reader {
+	if v := textprotoReaderPool.Get(); v != nil {
+		tr := v.(*textproto.Reader)
+		tr.R = br
+		return tr
+	}
+	return textproto.NewReader(br)
+}
+
+func putTextprotoReader(r *textproto.Reader) {
+	r.R = nil
+	textprotoReaderPool.Put(r)
+}
+
+// ReadRequest reads and parses a request from b.
+func ReadRequest(b *bufio.Reader) (req *Request, err error) {
+
+	tp := newTextprotoReader(b)
+	req = new(Request)
+
+	// First line: GET /index.html HTTP/1.0
+	var s string
+	if s, err = tp.ReadLine(); err != nil {
+		return nil, err
+	}
+	defer func() {
+		putTextprotoReader(tp)
+		if err == io.EOF {
+			err = io.ErrUnexpectedEOF
+		}
+	}()
+
+	var ok bool
+	req.Method, req.RequestURI, req.Proto, ok = parseRequestLine(s)
+	if !ok {
+		return nil, &badStringError{"malformed HTTP request", s}
+	}
+	rawurl := req.RequestURI
+	if req.ProtoMajor, req.ProtoMinor, ok = ParseHTTPVersion(req.Proto); !ok {
+		return nil, &badStringError{"malformed HTTP version", req.Proto}
+	}
+
+	// CONNECT requests are used two different ways, and neither uses a full URL:
+	// The standard use is to tunnel HTTPS through an HTTP proxy.
+	// It looks like "CONNECT www.google.com:443 HTTP/1.1", and the parameter is
+	// just the authority section of a URL. This information should go in req.URL.Host.
+	//
+	// The net/rpc package also uses CONNECT, but there the parameter is a path
+	// that starts with a slash. It can be parsed with the regular URL parser,
+	// and the path will end up in req.URL.Path, where it needs to be in order for
+	// RPC to work.
+	justAuthority := req.Method == "CONNECT" && !strings.HasPrefix(rawurl, "/")
+	if justAuthority {
+		rawurl = "http://" + rawurl
+	}
+
+	if req.URL, err = url.ParseRequestURI(rawurl); err != nil {
+		return nil, err
+	}
+
+	if justAuthority {
+		// Strip the bogus "http://" back off.
+		req.URL.Scheme = ""
+	}
+
+	// Subsequent lines: Key: value.
+	mimeHeader, err := tp.ReadMIMEHeader()
+	if err != nil {
+		return nil, err
+	}
+	req.Header = Header(mimeHeader)
+
+	// RFC2616: Must treat
+	//	GET /index.html HTTP/1.1
+	//	Host: www.google.com
+	// and
+	//	GET http://www.google.com/index.html HTTP/1.1
+	//	Host: doesntmatter
+	// the same.  In the second case, any Host line is ignored.
+	req.Host = req.URL.Host
+	if req.Host == "" {
+		req.Host = req.Header.get("Host")
+	}
+	delete(req.Header, "Host")
+
+	fixPragmaCacheControl(req.Header)
+
+	err = readTransfer(req, b)
+	if err != nil {
+		return nil, err
+	}
+
+	return req, nil
+}
+
+// MaxBytesReader is similar to io.LimitReader but is intended for
+// limiting the size of incoming request bodies. In contrast to
+// io.LimitReader, MaxBytesReader's result is a ReadCloser, returns a
+// non-EOF error for a Read beyond the limit, and Closes the
+// underlying reader when its Close method is called.
+//
+// MaxBytesReader prevents clients from accidentally or maliciously
+// sending a large request and wasting server resources.
+func MaxBytesReader(w ResponseWriter, r io.ReadCloser, n int64) io.ReadCloser {
+	return &maxBytesReader{w: w, r: r, n: n}
+}
+
+type maxBytesReader struct {
+	w       ResponseWriter
+	r       io.ReadCloser // underlying reader
+	n       int64         // max bytes remaining
+	stopped bool
+}
+
+func (l *maxBytesReader) Read(p []byte) (n int, err error) {
+	if l.n <= 0 {
+		if !l.stopped {
+			l.stopped = true
+			if res, ok := l.w.(*response); ok {
+				res.requestTooLarge()
+			}
+		}
+		return 0, errors.New("http: request body too large")
+	}
+	if int64(len(p)) > l.n {
+		p = p[:l.n]
+	}
+	n, err = l.r.Read(p)
+	l.n -= int64(n)
+	return
+}
+
+func (l *maxBytesReader) Close() error {
+	return l.r.Close()
+}
+
+func copyValues(dst, src url.Values) {
+	for k, vs := range src {
+		for _, value := range vs {
+			dst.Add(k, value)
+		}
+	}
+}
+
+func parsePostForm(r *Request) (vs url.Values, err error) {
+	if r.Body == nil {
+		err = errors.New("missing form body")
+		return
+	}
+	ct := r.Header.Get("Content-Type")
+	// RFC 2616, section 7.2.1 - empty type
+	//   SHOULD be treated as application/octet-stream
+	if ct == "" {
+		ct = "application/octet-stream"
+	}
+	ct, _, err = mime.ParseMediaType(ct)
+	switch {
+	case ct == "application/x-www-form-urlencoded":
+		var reader io.Reader = r.Body
+		maxFormSize := int64(1<<63 - 1)
+		if _, ok := r.Body.(*maxBytesReader); !ok {
+			maxFormSize = int64(10 << 20) // 10 MB is a lot of text.
+			reader = io.LimitReader(r.Body, maxFormSize+1)
+		}
+		b, e := ioutil.ReadAll(reader)
+		if e != nil {
+			if err == nil {
+				err = e
+			}
+			break
+		}
+		if int64(len(b)) > maxFormSize {
+			err = errors.New("http: POST too large")
+			return
+		}
+		vs, e = url.ParseQuery(string(b))
+		if err == nil {
+			err = e
+		}
+	case ct == "multipart/form-data":
+		// handled by ParseMultipartForm (which is calling us, or should be)
+		// TODO(bradfitz): there are too many possible
+		// orders to call too many functions here.
+		// Clean this up and write more tests.
+		// request_test.go contains the start of this,
+		// in TestParseMultipartFormOrder and others.
+	}
+	return
+}
+
+// ParseForm parses the raw query from the URL and updates r.Form.
+//
+// For POST or PUT requests, it also parses the request body as a form and
+// put the results into both r.PostForm and r.Form.
+// POST and PUT body parameters take precedence over URL query string values
+// in r.Form.
+//
+// If the request Body's size has not already been limited by MaxBytesReader,
+// the size is capped at 10MB.
+//
+// ParseMultipartForm calls ParseForm automatically.
+// It is idempotent.
+func (r *Request) ParseForm() error {
+	var err error
+	if r.PostForm == nil {
+		if r.Method == "POST" || r.Method == "PUT" || r.Method == "PATCH" {
+			r.PostForm, err = parsePostForm(r)
+		}
+		if r.PostForm == nil {
+			r.PostForm = make(url.Values)
+		}
+	}
+	if r.Form == nil {
+		if len(r.PostForm) > 0 {
+			r.Form = make(url.Values)
+			copyValues(r.Form, r.PostForm)
+		}
+		var newValues url.Values
+		if r.URL != nil {
+			var e error
+			newValues, e = url.ParseQuery(r.URL.RawQuery)
+			if err == nil {
+				err = e
+			}
+		}
+		if newValues == nil {
+			newValues = make(url.Values)
+		}
+		if r.Form == nil {
+			r.Form = newValues
+		} else {
+			copyValues(r.Form, newValues)
+		}
+	}
+	return err
+}
+
+// ParseMultipartForm parses a request body as multipart/form-data.
+// The whole request body is parsed and up to a total of maxMemory bytes of
+// its file parts are stored in memory, with the remainder stored on
+// disk in temporary files.
+// ParseMultipartForm calls ParseForm if necessary.
+// After one call to ParseMultipartForm, subsequent calls have no effect.
+func (r *Request) ParseMultipartForm(maxMemory int64) error {
+	if r.MultipartForm == multipartByReader {
+		return errors.New("http: multipart handled by MultipartReader")
+	}
+	if r.Form == nil {
+		err := r.ParseForm()
+		if err != nil {
+			return err
+		}
+	}
+	if r.MultipartForm != nil {
+		return nil
+	}
+
+	mr, err := r.multipartReader()
+	if err != nil {
+		return err
+	}
+
+	f, err := mr.ReadForm(maxMemory)
+	if err != nil {
+		return err
+	}
+	for k, v := range f.Value {
+		r.Form[k] = append(r.Form[k], v...)
+	}
+	r.MultipartForm = f
+
+	return nil
+}
+
+// FormValue returns the first value for the named component of the query.
+// POST and PUT body parameters take precedence over URL query string values.
+// FormValue calls ParseMultipartForm and ParseForm if necessary.
+// To access multiple values of the same key use ParseForm.
+func (r *Request) FormValue(key string) string {
+	if r.Form == nil {
+		r.ParseMultipartForm(defaultMaxMemory)
+	}
+	if vs := r.Form[key]; len(vs) > 0 {
+		return vs[0]
+	}
+	return ""
+}
+
+// PostFormValue returns the first value for the named component of the POST
+// or PUT request body. URL query parameters are ignored.
+// PostFormValue calls ParseMultipartForm and ParseForm if necessary.
+func (r *Request) PostFormValue(key string) string {
+	if r.PostForm == nil {
+		r.ParseMultipartForm(defaultMaxMemory)
+	}
+	if vs := r.PostForm[key]; len(vs) > 0 {
+		return vs[0]
+	}
+	return ""
+}
+
+// FormFile returns the first file for the provided form key.
+// FormFile calls ParseMultipartForm and ParseForm if necessary.
+func (r *Request) FormFile(key string) (multipart.File, *multipart.FileHeader, error) {
+	if r.MultipartForm == multipartByReader {
+		return nil, nil, errors.New("http: multipart handled by MultipartReader")
+	}
+	if r.MultipartForm == nil {
+		err := r.ParseMultipartForm(defaultMaxMemory)
+		if err != nil {
+			return nil, nil, err
+		}
+	}
+	if r.MultipartForm != nil && r.MultipartForm.File != nil {
+		if fhs := r.MultipartForm.File[key]; len(fhs) > 0 {
+			f, err := fhs[0].Open()
+			return f, fhs[0], err
+		}
+	}
+	return nil, nil, ErrMissingFile
+}
+
+func (r *Request) expectsContinue() bool {
+	return hasToken(r.Header.get("Expect"), "100-continue")
+}
+
+func (r *Request) wantsHttp10KeepAlive() bool {
+	if r.ProtoMajor != 1 || r.ProtoMinor != 0 {
+		return false
+	}
+	return hasToken(r.Header.get("Connection"), "keep-alive")
+}
+
+func (r *Request) wantsClose() bool {
+	return hasToken(r.Header.get("Connection"), "close")
+}
+
+func (r *Request) closeBody() {
+	if r.Body != nil {
+		r.Body.Close()
+	}
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/http/response.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/response.go
new file mode 100644
index 000000000..e1209a237
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/response.go
@@ -0,0 +1,291 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// HTTP Response reading and parsing.
+
+package http
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"github.com/masterzen/azure-sdk-for-go/core/tls"
+	"io"
+	"net/textproto"
+	"net/url"
+	"strconv"
+	"strings"
+)
+
+var respExcludeHeader = map[string]bool{
+	"Content-Length":    true,
+	"Transfer-Encoding": true,
+	"Trailer":           true,
+}
+
+// Response represents the response from an HTTP request.
+//
+type Response struct {
+	Status     string // e.g. "200 OK"
+	StatusCode int    // e.g. 200
+	Proto      string // e.g. "HTTP/1.0"
+	ProtoMajor int    // e.g. 1
+	ProtoMinor int    // e.g. 0
+
+	// Header maps header keys to values.  If the response had multiple
+	// headers with the same key, they may be concatenated, with comma
+	// delimiters.  (Section 4.2 of RFC 2616 requires that multiple headers
+	// be semantically equivalent to a comma-delimited sequence.) Values
+	// duplicated by other fields in this struct (e.g., ContentLength) are
+	// omitted from Header.
+	//
+	// Keys in the map are canonicalized (see CanonicalHeaderKey).
+	Header Header
+
+	// Body represents the response body.
+	//
+	// The http Client and Transport guarantee that Body is always
+	// non-nil, even on responses without a body or responses with
+	// a zero-length body. It is the caller's responsibility to
+	// close Body.
+	//
+	// The Body is automatically dechunked if the server replied
+	// with a "chunked" Transfer-Encoding.
+	Body io.ReadCloser
+
+	// ContentLength records the length of the associated content.  The
+	// value -1 indicates that the length is unknown.  Unless Request.Method
+	// is "HEAD", values >= 0 indicate that the given number of bytes may
+	// be read from Body.
+	ContentLength int64
+
+	// Contains transfer encodings from outer-most to inner-most. Value is
+	// nil, means that "identity" encoding is used.
+	TransferEncoding []string
+
+	// Close records whether the header directed that the connection be
+	// closed after reading Body.  The value is advice for clients: neither
+	// ReadResponse nor Response.Write ever closes a connection.
+	Close bool
+
+	// Trailer maps trailer keys to values, in the same
+	// format as the header.
+	Trailer Header
+
+	// The Request that was sent to obtain this Response.
+	// Request's Body is nil (having already been consumed).
+	// This is only populated for Client requests.
+	Request *Request
+
+	// TLS contains information about the TLS connection on which the
+	// response was received. It is nil for unencrypted responses.
+	// The pointer is shared between responses and should not be
+	// modified.
+	TLS *tls.ConnectionState
+}
+
+// Cookies parses and returns the cookies set in the Set-Cookie headers.
+func (r *Response) Cookies() []*Cookie {
+	return readSetCookies(r.Header)
+}
+
+var ErrNoLocation = errors.New("http: no Location header in response")
+
+// Location returns the URL of the response's "Location" header,
+// if present.  Relative redirects are resolved relative to
+// the Response's Request.  ErrNoLocation is returned if no
+// Location header is present.
+func (r *Response) Location() (*url.URL, error) {
+	lv := r.Header.Get("Location")
+	if lv == "" {
+		return nil, ErrNoLocation
+	}
+	if r.Request != nil && r.Request.URL != nil {
+		return r.Request.URL.Parse(lv)
+	}
+	return url.Parse(lv)
+}
+
+// ReadResponse reads and returns an HTTP response from r.
+// The req parameter optionally specifies the Request that corresponds
+// to this Response. If nil, a GET request is assumed.
+// Clients must call resp.Body.Close when finished reading resp.Body.
+// After that call, clients can inspect resp.Trailer to find key/value
+// pairs included in the response trailer.
+func ReadResponse(r *bufio.Reader, req *Request) (*Response, error) {
+	tp := textproto.NewReader(r)
+	resp := &Response{
+		Request: req,
+	}
+
+	// Parse the first line of the response.
+	line, err := tp.ReadLine()
+	if err != nil {
+		if err == io.EOF {
+			err = io.ErrUnexpectedEOF
+		}
+		return nil, err
+	}
+	f := strings.SplitN(line, " ", 3)
+	if len(f) < 2 {
+		return nil, &badStringError{"malformed HTTP response", line}
+	}
+	reasonPhrase := ""
+	if len(f) > 2 {
+		reasonPhrase = f[2]
+	}
+	resp.Status = f[1] + " " + reasonPhrase
+	resp.StatusCode, err = strconv.Atoi(f[1])
+	if err != nil {
+		return nil, &badStringError{"malformed HTTP status code", f[1]}
+	}
+
+	resp.Proto = f[0]
+	var ok bool
+	if resp.ProtoMajor, resp.ProtoMinor, ok = ParseHTTPVersion(resp.Proto); !ok {
+		return nil, &badStringError{"malformed HTTP version", resp.Proto}
+	}
+
+	// Parse the response headers.
+	mimeHeader, err := tp.ReadMIMEHeader()
+	if err != nil {
+		if err == io.EOF {
+			err = io.ErrUnexpectedEOF
+		}
+		return nil, err
+	}
+	resp.Header = Header(mimeHeader)
+
+	fixPragmaCacheControl(resp.Header)
+
+	err = readTransfer(resp, r)
+	if err != nil {
+		return nil, err
+	}
+
+	return resp, nil
+}
+
+// RFC2616: Should treat
+//	Pragma: no-cache
+// like
+//	Cache-Control: no-cache
+func fixPragmaCacheControl(header Header) {
+	if hp, ok := header["Pragma"]; ok && len(hp) > 0 && hp[0] == "no-cache" {
+		if _, presentcc := header["Cache-Control"]; !presentcc {
+			header["Cache-Control"] = []string{"no-cache"}
+		}
+	}
+}
+
+// ProtoAtLeast reports whether the HTTP protocol used
+// in the response is at least major.minor.
+func (r *Response) ProtoAtLeast(major, minor int) bool {
+	return r.ProtoMajor > major ||
+		r.ProtoMajor == major && r.ProtoMinor >= minor
+}
+
+// Writes the response (header, body and trailer) in wire format. This method
+// consults the following fields of the response:
+//
+//  StatusCode
+//  ProtoMajor
+//  ProtoMinor
+//  Request.Method
+//  TransferEncoding
+//  Trailer
+//  Body
+//  ContentLength
+//  Header, values for non-canonical keys will have unpredictable behavior
+//
+// Body is closed after it is sent.
+func (r *Response) Write(w io.Writer) error {
+	// Status line
+	text := r.Status
+	if text == "" {
+		var ok bool
+		text, ok = statusText[r.StatusCode]
+		if !ok {
+			text = "status code " + strconv.Itoa(r.StatusCode)
+		}
+	}
+	protoMajor, protoMinor := strconv.Itoa(r.ProtoMajor), strconv.Itoa(r.ProtoMinor)
+	statusCode := strconv.Itoa(r.StatusCode) + " "
+	text = strings.TrimPrefix(text, statusCode)
+	if _, err := io.WriteString(w, "HTTP/"+protoMajor+"."+protoMinor+" "+statusCode+text+"\r\n"); err != nil {
+		return err
+	}
+
+	// Clone it, so we can modify r1 as needed.
+	r1 := new(Response)
+	*r1 = *r
+	if r1.ContentLength == 0 && r1.Body != nil {
+		// Is it actually 0 length? Or just unknown?
+		var buf [1]byte
+		n, err := r1.Body.Read(buf[:])
+		if err != nil && err != io.EOF {
+			return err
+		}
+		if n == 0 {
+			// Reset it to a known zero reader, in case underlying one
+			// is unhappy being read repeatedly.
+			r1.Body = eofReader
+		} else {
+			r1.ContentLength = -1
+			r1.Body = struct {
+				io.Reader
+				io.Closer
+			}{
+				io.MultiReader(bytes.NewReader(buf[:1]), r.Body),
+				r.Body,
+			}
+		}
+	}
+	// If we're sending a non-chunked HTTP/1.1 response without a
+	// content-length, the only way to do that is the old HTTP/1.0
+	// way, by noting the EOF with a connection close, so we need
+	// to set Close.
+	if r1.ContentLength == -1 && !r1.Close && r1.ProtoAtLeast(1, 1) && !chunked(r1.TransferEncoding) {
+		r1.Close = true
+	}
+
+	// Process Body,ContentLength,Close,Trailer
+	tw, err := newTransferWriter(r1)
+	if err != nil {
+		return err
+	}
+	err = tw.WriteHeader(w)
+	if err != nil {
+		return err
+	}
+
+	// Rest of header
+	err = r.Header.WriteSubset(w, respExcludeHeader)
+	if err != nil {
+		return err
+	}
+
+	// contentLengthAlreadySent may have been already sent for
+	// POST/PUT requests, even if zero length. See Issue 8180.
+	contentLengthAlreadySent := tw.shouldSendContentLength()
+	if r1.ContentLength == 0 && !chunked(r1.TransferEncoding) && !contentLengthAlreadySent {
+		if _, err := io.WriteString(w, "Content-Length: 0\r\n"); err != nil {
+			return err
+		}
+	}
+
+	// End-of-header
+	if _, err := io.WriteString(w, "\r\n"); err != nil {
+		return err
+	}
+
+	// Write body and trailer
+	err = tw.WriteBody(w)
+	if err != nil {
+		return err
+	}
+
+	// Success
+	return nil
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/http/server.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/server.go
new file mode 100644
index 000000000..eae097eb8
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/server.go
@@ -0,0 +1,2052 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// HTTP server.  See RFC 2616.
+
+package http
+
+import (
+	"bufio"
+	"crypto/tls"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"net"
+	"net/url"
+	"os"
+	"path"
+	"runtime"
+	"strconv"
+	"strings"
+	"sync"
+	"sync/atomic"
+	"time"
+)
+
+// Errors introduced by the HTTP server.
+var (
+	ErrWriteAfterFlush = errors.New("Conn.Write called after Flush")
+	ErrBodyNotAllowed  = errors.New("http: request method or response status code does not allow body")
+	ErrHijacked        = errors.New("Conn has been hijacked")
+	ErrContentLength   = errors.New("Conn.Write wrote more than the declared Content-Length")
+)
+
+// Objects implementing the Handler interface can be
+// registered to serve a particular path or subtree
+// in the HTTP server.
+//
+// ServeHTTP should write reply headers and data to the ResponseWriter
+// and then return.  Returning signals that the request is finished
+// and that the HTTP server can move on to the next request on
+// the connection.
+type Handler interface {
+	ServeHTTP(ResponseWriter, *Request)
+}
+
+// A ResponseWriter interface is used by an HTTP handler to
+// construct an HTTP response.
+type ResponseWriter interface {
+	// Header returns the header map that will be sent by WriteHeader.
+	// Changing the header after a call to WriteHeader (or Write) has
+	// no effect.
+	Header() Header
+
+	// Write writes the data to the connection as part of an HTTP reply.
+	// If WriteHeader has not yet been called, Write calls WriteHeader(http.StatusOK)
+	// before writing the data.  If the Header does not contain a
+	// Content-Type line, Write adds a Content-Type set to the result of passing
+	// the initial 512 bytes of written data to DetectContentType.
+	Write([]byte) (int, error)
+
+	// WriteHeader sends an HTTP response header with status code.
+	// If WriteHeader is not called explicitly, the first call to Write
+	// will trigger an implicit WriteHeader(http.StatusOK).
+	// Thus explicit calls to WriteHeader are mainly used to
+	// send error codes.
+	WriteHeader(int)
+}
+
+// The Flusher interface is implemented by ResponseWriters that allow
+// an HTTP handler to flush buffered data to the client.
+//
+// Note that even for ResponseWriters that support Flush,
+// if the client is connected through an HTTP proxy,
+// the buffered data may not reach the client until the response
+// completes.
+type Flusher interface {
+	// Flush sends any buffered data to the client.
+	Flush()
+}
+
+// The Hijacker interface is implemented by ResponseWriters that allow
+// an HTTP handler to take over the connection.
+type Hijacker interface {
+	// Hijack lets the caller take over the connection.
+	// After a call to Hijack(), the HTTP server library
+	// will not do anything else with the connection.
+	// It becomes the caller's responsibility to manage
+	// and close the connection.
+	Hijack() (net.Conn, *bufio.ReadWriter, error)
+}
+
+// The CloseNotifier interface is implemented by ResponseWriters which
+// allow detecting when the underlying connection has gone away.
+//
+// This mechanism can be used to cancel long operations on the server
+// if the client has disconnected before the response is ready.
+type CloseNotifier interface {
+	// CloseNotify returns a channel that receives a single value
+	// when the client connection has gone away.
+	CloseNotify() <-chan bool
+}
+
+// A conn represents the server side of an HTTP connection.
+type conn struct {
+	remoteAddr string               // network address of remote side
+	server     *Server              // the Server on which the connection arrived
+	rwc        net.Conn             // i/o connection
+	sr         liveSwitchReader     // where the LimitReader reads from; usually the rwc
+	lr         *io.LimitedReader    // io.LimitReader(sr)
+	buf        *bufio.ReadWriter    // buffered(lr,rwc), reading from bufio->limitReader->sr->rwc
+	tlsState   *tls.ConnectionState // or nil when not using TLS
+
+	mu           sync.Mutex // guards the following
+	clientGone   bool       // if client has disconnected mid-request
+	closeNotifyc chan bool  // made lazily
+	hijackedv    bool       // connection has been hijacked by handler
+}
+
+func (c *conn) hijacked() bool {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	return c.hijackedv
+}
+
+func (c *conn) hijack() (rwc net.Conn, buf *bufio.ReadWriter, err error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.hijackedv {
+		return nil, nil, ErrHijacked
+	}
+	if c.closeNotifyc != nil {
+		return nil, nil, errors.New("http: Hijack is incompatible with use of CloseNotifier")
+	}
+	c.hijackedv = true
+	rwc = c.rwc
+	buf = c.buf
+	c.rwc = nil
+	c.buf = nil
+	c.setState(rwc, StateHijacked)
+	return
+}
+
+func (c *conn) closeNotify() <-chan bool {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.closeNotifyc == nil {
+		c.closeNotifyc = make(chan bool, 1)
+		if c.hijackedv {
+			// to obey the function signature, even though
+			// it'll never receive a value.
+			return c.closeNotifyc
+		}
+		pr, pw := io.Pipe()
+
+		readSource := c.sr.r
+		c.sr.Lock()
+		c.sr.r = pr
+		c.sr.Unlock()
+		go func() {
+			_, err := io.Copy(pw, readSource)
+			if err == nil {
+				err = io.EOF
+			}
+			pw.CloseWithError(err)
+			c.noteClientGone()
+		}()
+	}
+	return c.closeNotifyc
+}
+
+func (c *conn) noteClientGone() {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.closeNotifyc != nil && !c.clientGone {
+		c.closeNotifyc <- true
+	}
+	c.clientGone = true
+}
+
+// A switchReader can have its Reader changed at runtime.
+// It's not safe for concurrent Reads and switches.
+type switchReader struct {
+	io.Reader
+}
+
+// A switchWriter can have its Writer changed at runtime.
+// It's not safe for concurrent Writes and switches.
+type switchWriter struct {
+	io.Writer
+}
+
+// A liveSwitchReader is a switchReader that's safe for concurrent
+// reads and switches, if its mutex is held.
+type liveSwitchReader struct {
+	sync.Mutex
+	r io.Reader
+}
+
+func (sr *liveSwitchReader) Read(p []byte) (n int, err error) {
+	sr.Lock()
+	r := sr.r
+	sr.Unlock()
+	return r.Read(p)
+}
+
+// This should be >= 512 bytes for DetectContentType,
+// but otherwise it's somewhat arbitrary.
+const bufferBeforeChunkingSize = 2048
+
+// chunkWriter writes to a response's conn buffer, and is the writer
+// wrapped by the response.bufw buffered writer.
+//
+// chunkWriter also is responsible for finalizing the Header, including
+// conditionally setting the Content-Type and setting a Content-Length
+// in cases where the handler's final output is smaller than the buffer
+// size. It also conditionally adds chunk headers, when in chunking mode.
+//
+// See the comment above (*response).Write for the entire write flow.
+type chunkWriter struct {
+	res *response
+
+	// header is either nil or a deep clone of res.handlerHeader
+	// at the time of res.WriteHeader, if res.WriteHeader is
+	// called and extra buffering is being done to calculate
+	// Content-Type and/or Content-Length.
+	header Header
+
+	// wroteHeader tells whether the header's been written to "the
+	// wire" (or rather: w.conn.buf). this is unlike
+	// (*response).wroteHeader, which tells only whether it was
+	// logically written.
+	wroteHeader bool
+
+	// set by the writeHeader method:
+	chunking bool // using chunked transfer encoding for reply body
+}
+
+var (
+	crlf       = []byte("\r\n")
+	colonSpace = []byte(": ")
+)
+
+func (cw *chunkWriter) Write(p []byte) (n int, err error) {
+	if !cw.wroteHeader {
+		cw.writeHeader(p)
+	}
+	if cw.res.req.Method == "HEAD" {
+		// Eat writes.
+		return len(p), nil
+	}
+	if cw.chunking {
+		_, err = fmt.Fprintf(cw.res.conn.buf, "%x\r\n", len(p))
+		if err != nil {
+			cw.res.conn.rwc.Close()
+			return
+		}
+	}
+	n, err = cw.res.conn.buf.Write(p)
+	if cw.chunking && err == nil {
+		_, err = cw.res.conn.buf.Write(crlf)
+	}
+	if err != nil {
+		cw.res.conn.rwc.Close()
+	}
+	return
+}
+
+func (cw *chunkWriter) flush() {
+	if !cw.wroteHeader {
+		cw.writeHeader(nil)
+	}
+	cw.res.conn.buf.Flush()
+}
+
+func (cw *chunkWriter) close() {
+	if !cw.wroteHeader {
+		cw.writeHeader(nil)
+	}
+	if cw.chunking {
+		// zero EOF chunk, trailer key/value pairs (currently
+		// unsupported in Go's server), followed by a blank
+		// line.
+		cw.res.conn.buf.WriteString("0\r\n\r\n")
+	}
+}
+
+// A response represents the server side of an HTTP response.
+type response struct {
+	conn          *conn
+	req           *Request // request for this response
+	wroteHeader   bool     // reply header has been (logically) written
+	wroteContinue bool     // 100 Continue response was written
+
+	w  *bufio.Writer // buffers output in chunks to chunkWriter
+	cw chunkWriter
+	sw *switchWriter // of the bufio.Writer, for return to putBufioWriter
+
+	// handlerHeader is the Header that Handlers get access to,
+	// which may be retained and mutated even after WriteHeader.
+	// handlerHeader is copied into cw.header at WriteHeader
+	// time, and privately mutated thereafter.
+	handlerHeader Header
+	calledHeader  bool // handler accessed handlerHeader via Header
+
+	written       int64 // number of bytes written in body
+	contentLength int64 // explicitly-declared Content-Length; or -1
+	status        int   // status code passed to WriteHeader
+
+	// close connection after this reply.  set on request and
+	// updated after response from handler if there's a
+	// "Connection: keep-alive" response header and a
+	// Content-Length.
+	closeAfterReply bool
+
+	// requestBodyLimitHit is set by requestTooLarge when
+	// maxBytesReader hits its max size. It is checked in
+	// WriteHeader, to make sure we don't consume the
+	// remaining request body to try to advance to the next HTTP
+	// request. Instead, when this is set, we stop reading
+	// subsequent requests on this connection and stop reading
+	// input from it.
+	requestBodyLimitHit bool
+
+	handlerDone bool // set true when the handler exits
+
+	// Buffers for Date and Content-Length
+	dateBuf [len(TimeFormat)]byte
+	clenBuf [10]byte
+}
+
+// requestTooLarge is called by maxBytesReader when too much input has
+// been read from the client.
+func (w *response) requestTooLarge() {
+	w.closeAfterReply = true
+	w.requestBodyLimitHit = true
+	if !w.wroteHeader {
+		w.Header().Set("Connection", "close")
+	}
+}
+
+// needsSniff reports whether a Content-Type still needs to be sniffed.
+func (w *response) needsSniff() bool {
+	_, haveType := w.handlerHeader["Content-Type"]
+	return !w.cw.wroteHeader && !haveType && w.written < sniffLen
+}
+
+// writerOnly hides an io.Writer value's optional ReadFrom method
+// from io.Copy.
+type writerOnly struct {
+	io.Writer
+}
+
+func srcIsRegularFile(src io.Reader) (isRegular bool, err error) {
+	switch v := src.(type) {
+	case *os.File:
+		fi, err := v.Stat()
+		if err != nil {
+			return false, err
+		}
+		return fi.Mode().IsRegular(), nil
+	case *io.LimitedReader:
+		return srcIsRegularFile(v.R)
+	default:
+		return
+	}
+}
+
+// ReadFrom is here to optimize copying from an *os.File regular file
+// to a *net.TCPConn with sendfile.
+func (w *response) ReadFrom(src io.Reader) (n int64, err error) {
+	// Our underlying w.conn.rwc is usually a *TCPConn (with its
+	// own ReadFrom method). If not, or if our src isn't a regular
+	// file, just fall back to the normal copy method.
+	rf, ok := w.conn.rwc.(io.ReaderFrom)
+	regFile, err := srcIsRegularFile(src)
+	if err != nil {
+		return 0, err
+	}
+	if !ok || !regFile {
+		return io.Copy(writerOnly{w}, src)
+	}
+
+	// sendfile path:
+
+	if !w.wroteHeader {
+		w.WriteHeader(StatusOK)
+	}
+
+	if w.needsSniff() {
+		n0, err := io.Copy(writerOnly{w}, io.LimitReader(src, sniffLen))
+		n += n0
+		if err != nil {
+			return n, err
+		}
+	}
+
+	w.w.Flush()  // get rid of any previous writes
+	w.cw.flush() // make sure Header is written; flush data to rwc
+
+	// Now that cw has been flushed, its chunking field is guaranteed initialized.
+	if !w.cw.chunking && w.bodyAllowed() {
+		n0, err := rf.ReadFrom(src)
+		n += n0
+		w.written += n0
+		return n, err
+	}
+
+	n0, err := io.Copy(writerOnly{w}, src)
+	n += n0
+	return n, err
+}
+
+// noLimit is an effective infinite upper bound for io.LimitedReader
+const noLimit int64 = (1 << 63) - 1
+
+// debugServerConnections controls whether all server connections are wrapped
+// with a verbose logging wrapper.
+const debugServerConnections = false
+
+// Create new connection from rwc.
+func (srv *Server) newConn(rwc net.Conn) (c *conn, err error) {
+	c = new(conn)
+	c.remoteAddr = rwc.RemoteAddr().String()
+	c.server = srv
+	c.rwc = rwc
+	if debugServerConnections {
+		c.rwc = newLoggingConn("server", c.rwc)
+	}
+	c.sr = liveSwitchReader{r: c.rwc}
+	c.lr = io.LimitReader(&c.sr, noLimit).(*io.LimitedReader)
+	br := newBufioReader(c.lr)
+	bw := newBufioWriterSize(c.rwc, 4<<10)
+	c.buf = bufio.NewReadWriter(br, bw)
+	return c, nil
+}
+
+var (
+	bufioReaderPool   sync.Pool
+	bufioWriter2kPool sync.Pool
+	bufioWriter4kPool sync.Pool
+)
+
+func bufioWriterPool(size int) *sync.Pool {
+	switch size {
+	case 2 << 10:
+		return &bufioWriter2kPool
+	case 4 << 10:
+		return &bufioWriter4kPool
+	}
+	return nil
+}
+
+func newBufioReader(r io.Reader) *bufio.Reader {
+	if v := bufioReaderPool.Get(); v != nil {
+		br := v.(*bufio.Reader)
+		br.Reset(r)
+		return br
+	}
+	return bufio.NewReader(r)
+}
+
+func putBufioReader(br *bufio.Reader) {
+	br.Reset(nil)
+	bufioReaderPool.Put(br)
+}
+
+func newBufioWriterSize(w io.Writer, size int) *bufio.Writer {
+	pool := bufioWriterPool(size)
+	if pool != nil {
+		if v := pool.Get(); v != nil {
+			bw := v.(*bufio.Writer)
+			bw.Reset(w)
+			return bw
+		}
+	}
+	return bufio.NewWriterSize(w, size)
+}
+
+func putBufioWriter(bw *bufio.Writer) {
+	bw.Reset(nil)
+	if pool := bufioWriterPool(bw.Available()); pool != nil {
+		pool.Put(bw)
+	}
+}
+
+// DefaultMaxHeaderBytes is the maximum permitted size of the headers
+// in an HTTP request.
+// This can be overridden by setting Server.MaxHeaderBytes.
+const DefaultMaxHeaderBytes = 1 << 20 // 1 MB
+
+func (srv *Server) maxHeaderBytes() int {
+	if srv.MaxHeaderBytes > 0 {
+		return srv.MaxHeaderBytes
+	}
+	return DefaultMaxHeaderBytes
+}
+
+func (srv *Server) initialLimitedReaderSize() int64 {
+	return int64(srv.maxHeaderBytes()) + 4096 // bufio slop
+}
+
+// wrapper around io.ReaderCloser which on first read, sends an
+// HTTP/1.1 100 Continue header
+type expectContinueReader struct {
+	resp       *response
+	readCloser io.ReadCloser
+	closed     bool
+}
+
+func (ecr *expectContinueReader) Read(p []byte) (n int, err error) {
+	if ecr.closed {
+		return 0, ErrBodyReadAfterClose
+	}
+	if !ecr.resp.wroteContinue && !ecr.resp.conn.hijacked() {
+		ecr.resp.wroteContinue = true
+		ecr.resp.conn.buf.WriteString("HTTP/1.1 100 Continue\r\n\r\n")
+		ecr.resp.conn.buf.Flush()
+	}
+	return ecr.readCloser.Read(p)
+}
+
+func (ecr *expectContinueReader) Close() error {
+	ecr.closed = true
+	return ecr.readCloser.Close()
+}
+
+// TimeFormat is the time format to use with
+// time.Parse and time.Time.Format when parsing
+// or generating times in HTTP headers.
+// It is like time.RFC1123 but hard codes GMT as the time zone.
+const TimeFormat = "Mon, 02 Jan 2006 15:04:05 GMT"
+
+// appendTime is a non-allocating version of []byte(t.UTC().Format(TimeFormat))
+func appendTime(b []byte, t time.Time) []byte {
+	const days = "SunMonTueWedThuFriSat"
+	const months = "JanFebMarAprMayJunJulAugSepOctNovDec"
+
+	t = t.UTC()
+	yy, mm, dd := t.Date()
+	hh, mn, ss := t.Clock()
+	day := days[3*t.Weekday():]
+	mon := months[3*(mm-1):]
+
+	return append(b,
+		day[0], day[1], day[2], ',', ' ',
+		byte('0'+dd/10), byte('0'+dd%10), ' ',
+		mon[0], mon[1], mon[2], ' ',
+		byte('0'+yy/1000), byte('0'+(yy/100)%10), byte('0'+(yy/10)%10), byte('0'+yy%10), ' ',
+		byte('0'+hh/10), byte('0'+hh%10), ':',
+		byte('0'+mn/10), byte('0'+mn%10), ':',
+		byte('0'+ss/10), byte('0'+ss%10), ' ',
+		'G', 'M', 'T')
+}
+
+var errTooLarge = errors.New("http: request too large")
+
+// Read next request from connection.
+func (c *conn) readRequest() (w *response, err error) {
+	if c.hijacked() {
+		return nil, ErrHijacked
+	}
+
+	if d := c.server.ReadTimeout; d != 0 {
+		c.rwc.SetReadDeadline(time.Now().Add(d))
+	}
+	if d := c.server.WriteTimeout; d != 0 {
+		defer func() {
+			c.rwc.SetWriteDeadline(time.Now().Add(d))
+		}()
+	}
+
+	c.lr.N = c.server.initialLimitedReaderSize()
+	var req *Request
+	if req, err = ReadRequest(c.buf.Reader); err != nil {
+		if c.lr.N == 0 {
+			return nil, errTooLarge
+		}
+		return nil, err
+	}
+	c.lr.N = noLimit
+
+	req.RemoteAddr = c.remoteAddr
+	req.TLS = c.tlsState
+
+	w = &response{
+		conn:          c,
+		req:           req,
+		handlerHeader: make(Header),
+		contentLength: -1,
+	}
+	w.cw.res = w
+	w.w = newBufioWriterSize(&w.cw, bufferBeforeChunkingSize)
+	return w, nil
+}
+
+func (w *response) Header() Header {
+	if w.cw.header == nil && w.wroteHeader && !w.cw.wroteHeader {
+		// Accessing the header between logically writing it
+		// and physically writing it means we need to allocate
+		// a clone to snapshot the logically written state.
+		w.cw.header = w.handlerHeader.clone()
+	}
+	w.calledHeader = true
+	return w.handlerHeader
+}
+
+// maxPostHandlerReadBytes is the max number of Request.Body bytes not
+// consumed by a handler that the server will read from the client
+// in order to keep a connection alive.  If there are more bytes than
+// this then the server to be paranoid instead sends a "Connection:
+// close" response.
+//
+// This number is approximately what a typical machine's TCP buffer
+// size is anyway.  (if we have the bytes on the machine, we might as
+// well read them)
+const maxPostHandlerReadBytes = 256 << 10
+
+func (w *response) WriteHeader(code int) {
+	if w.conn.hijacked() {
+		w.conn.server.logf("http: response.WriteHeader on hijacked connection")
+		return
+	}
+	if w.wroteHeader {
+		w.conn.server.logf("http: multiple response.WriteHeader calls")
+		return
+	}
+	w.wroteHeader = true
+	w.status = code
+
+	if w.calledHeader && w.cw.header == nil {
+		w.cw.header = w.handlerHeader.clone()
+	}
+
+	if cl := w.handlerHeader.get("Content-Length"); cl != "" {
+		v, err := strconv.ParseInt(cl, 10, 64)
+		if err == nil && v >= 0 {
+			w.contentLength = v
+		} else {
+			w.conn.server.logf("http: invalid Content-Length of %q", cl)
+			w.handlerHeader.Del("Content-Length")
+		}
+	}
+}
+
+// extraHeader is the set of headers sometimes added by chunkWriter.writeHeader.
+// This type is used to avoid extra allocations from cloning and/or populating
+// the response Header map and all its 1-element slices.
+type extraHeader struct {
+	contentType      string
+	connection       string
+	transferEncoding string
+	date             []byte // written if not nil
+	contentLength    []byte // written if not nil
+}
+
+// Sorted the same as extraHeader.Write's loop.
+var extraHeaderKeys = [][]byte{
+	[]byte("Content-Type"),
+	[]byte("Connection"),
+	[]byte("Transfer-Encoding"),
+}
+
+var (
+	headerContentLength = []byte("Content-Length: ")
+	headerDate          = []byte("Date: ")
+)
+
+// Write writes the headers described in h to w.
+//
+// This method has a value receiver, despite the somewhat large size
+// of h, because it prevents an allocation. The escape analysis isn't
+// smart enough to realize this function doesn't mutate h.
+func (h extraHeader) Write(w *bufio.Writer) {
+	if h.date != nil {
+		w.Write(headerDate)
+		w.Write(h.date)
+		w.Write(crlf)
+	}
+	if h.contentLength != nil {
+		w.Write(headerContentLength)
+		w.Write(h.contentLength)
+		w.Write(crlf)
+	}
+	for i, v := range []string{h.contentType, h.connection, h.transferEncoding} {
+		if v != "" {
+			w.Write(extraHeaderKeys[i])
+			w.Write(colonSpace)
+			w.WriteString(v)
+			w.Write(crlf)
+		}
+	}
+}
+
+// writeHeader finalizes the header sent to the client and writes it
+// to cw.res.conn.buf.
+//
+// p is not written by writeHeader, but is the first chunk of the body
+// that will be written.  It is sniffed for a Content-Type if none is
+// set explicitly.  It's also used to set the Content-Length, if the
+// total body size was small and the handler has already finished
+// running.
+func (cw *chunkWriter) writeHeader(p []byte) {
+	if cw.wroteHeader {
+		return
+	}
+	cw.wroteHeader = true
+
+	w := cw.res
+	keepAlivesEnabled := w.conn.server.doKeepAlives()
+	isHEAD := w.req.Method == "HEAD"
+
+	// header is written out to w.conn.buf below. Depending on the
+	// state of the handler, we either own the map or not. If we
+	// don't own it, the exclude map is created lazily for
+	// WriteSubset to remove headers. The setHeader struct holds
+	// headers we need to add.
+	header := cw.header
+	owned := header != nil
+	if !owned {
+		header = w.handlerHeader
+	}
+	var excludeHeader map[string]bool
+	delHeader := func(key string) {
+		if owned {
+			header.Del(key)
+			return
+		}
+		if _, ok := header[key]; !ok {
+			return
+		}
+		if excludeHeader == nil {
+			excludeHeader = make(map[string]bool)
+		}
+		excludeHeader[key] = true
+	}
+	var setHeader extraHeader
+
+	// If the handler is done but never sent a Content-Length
+	// response header and this is our first (and last) write, set
+	// it, even to zero. This helps HTTP/1.0 clients keep their
+	// "keep-alive" connections alive.
+	// Exceptions: 304/204/1xx responses never get Content-Length, and if
+	// it was a HEAD request, we don't know the difference between
+	// 0 actual bytes and 0 bytes because the handler noticed it
+	// was a HEAD request and chose not to write anything.  So for
+	// HEAD, the handler should either write the Content-Length or
+	// write non-zero bytes.  If it's actually 0 bytes and the
+	// handler never looked at the Request.Method, we just don't
+	// send a Content-Length header.
+	if w.handlerDone && bodyAllowedForStatus(w.status) && header.get("Content-Length") == "" && (!isHEAD || len(p) > 0) {
+		w.contentLength = int64(len(p))
+		setHeader.contentLength = strconv.AppendInt(cw.res.clenBuf[:0], int64(len(p)), 10)
+	}
+
+	// If this was an HTTP/1.0 request with keep-alive and we sent a
+	// Content-Length back, we can make this a keep-alive response ...
+	if w.req.wantsHttp10KeepAlive() && keepAlivesEnabled {
+		sentLength := header.get("Content-Length") != ""
+		if sentLength && header.get("Connection") == "keep-alive" {
+			w.closeAfterReply = false
+		}
+	}
+
+	// Check for a explicit (and valid) Content-Length header.
+	hasCL := w.contentLength != -1
+
+	if w.req.wantsHttp10KeepAlive() && (isHEAD || hasCL) {
+		_, connectionHeaderSet := header["Connection"]
+		if !connectionHeaderSet {
+			setHeader.connection = "keep-alive"
+		}
+	} else if !w.req.ProtoAtLeast(1, 1) || w.req.wantsClose() {
+		w.closeAfterReply = true
+	}
+
+	if header.get("Connection") == "close" || !keepAlivesEnabled {
+		w.closeAfterReply = true
+	}
+
+	// Per RFC 2616, we should consume the request body before
+	// replying, if the handler hasn't already done so.  But we
+	// don't want to do an unbounded amount of reading here for
+	// DoS reasons, so we only try up to a threshold.
+	if w.req.ContentLength != 0 && !w.closeAfterReply {
+		ecr, isExpecter := w.req.Body.(*expectContinueReader)
+		if !isExpecter || ecr.resp.wroteContinue {
+			n, _ := io.CopyN(ioutil.Discard, w.req.Body, maxPostHandlerReadBytes+1)
+			if n >= maxPostHandlerReadBytes {
+				w.requestTooLarge()
+				delHeader("Connection")
+				setHeader.connection = "close"
+			} else {
+				w.req.Body.Close()
+			}
+		}
+	}
+
+	code := w.status
+	if bodyAllowedForStatus(code) {
+		// If no content type, apply sniffing algorithm to body.
+		_, haveType := header["Content-Type"]
+		if !haveType {
+			setHeader.contentType = DetectContentType(p)
+		}
+	} else {
+		for _, k := range suppressedHeaders(code) {
+			delHeader(k)
+		}
+	}
+
+	if _, ok := header["Date"]; !ok {
+		setHeader.date = appendTime(cw.res.dateBuf[:0], time.Now())
+	}
+
+	te := header.get("Transfer-Encoding")
+	hasTE := te != ""
+	if hasCL && hasTE && te != "identity" {
+		// TODO: return an error if WriteHeader gets a return parameter
+		// For now just ignore the Content-Length.
+		w.conn.server.logf("http: WriteHeader called with both Transfer-Encoding of %q and a Content-Length of %d",
+			te, w.contentLength)
+		delHeader("Content-Length")
+		hasCL = false
+	}
+
+	if w.req.Method == "HEAD" || !bodyAllowedForStatus(code) {
+		// do nothing
+	} else if code == StatusNoContent {
+		delHeader("Transfer-Encoding")
+	} else if hasCL {
+		delHeader("Transfer-Encoding")
+	} else if w.req.ProtoAtLeast(1, 1) {
+		// HTTP/1.1 or greater: use chunked transfer encoding
+		// to avoid closing the connection at EOF.
+		// TODO: this blows away any custom or stacked Transfer-Encoding they
+		// might have set.  Deal with that as need arises once we have a valid
+		// use case.
+		cw.chunking = true
+		setHeader.transferEncoding = "chunked"
+	} else {
+		// HTTP version < 1.1: cannot do chunked transfer
+		// encoding and we don't know the Content-Length so
+		// signal EOF by closing connection.
+		w.closeAfterReply = true
+		delHeader("Transfer-Encoding") // in case already set
+	}
+
+	// Cannot use Content-Length with non-identity Transfer-Encoding.
+	if cw.chunking {
+		delHeader("Content-Length")
+	}
+	if !w.req.ProtoAtLeast(1, 0) {
+		return
+	}
+
+	if w.closeAfterReply && (!keepAlivesEnabled || !hasToken(cw.header.get("Connection"), "close")) {
+		delHeader("Connection")
+		if w.req.ProtoAtLeast(1, 1) {
+			setHeader.connection = "close"
+		}
+	}
+
+	w.conn.buf.WriteString(statusLine(w.req, code))
+	cw.header.WriteSubset(w.conn.buf, excludeHeader)
+	setHeader.Write(w.conn.buf.Writer)
+	w.conn.buf.Write(crlf)
+}
+
+// statusLines is a cache of Status-Line strings, keyed by code (for
+// HTTP/1.1) or negative code (for HTTP/1.0). This is faster than a
+// map keyed by struct of two fields. This map's max size is bounded
+// by 2*len(statusText), two protocol types for each known official
+// status code in the statusText map.
+var (
+	statusMu    sync.RWMutex
+	statusLines = make(map[int]string)
+)
+
+// statusLine returns a response Status-Line (RFC 2616 Section 6.1)
+// for the given request and response status code.
+func statusLine(req *Request, code int) string {
+	// Fast path:
+	key := code
+	proto11 := req.ProtoAtLeast(1, 1)
+	if !proto11 {
+		key = -key
+	}
+	statusMu.RLock()
+	line, ok := statusLines[key]
+	statusMu.RUnlock()
+	if ok {
+		return line
+	}
+
+	// Slow path:
+	proto := "HTTP/1.0"
+	if proto11 {
+		proto = "HTTP/1.1"
+	}
+	codestring := strconv.Itoa(code)
+	text, ok := statusText[code]
+	if !ok {
+		text = "status code " + codestring
+	}
+	line = proto + " " + codestring + " " + text + "\r\n"
+	if ok {
+		statusMu.Lock()
+		defer statusMu.Unlock()
+		statusLines[key] = line
+	}
+	return line
+}
+
+// bodyAllowed returns true if a Write is allowed for this response type.
+// It's illegal to call this before the header has been flushed.
+func (w *response) bodyAllowed() bool {
+	if !w.wroteHeader {
+		panic("")
+	}
+	return bodyAllowedForStatus(w.status)
+}
+
+// The Life Of A Write is like this:
+//
+// Handler starts. No header has been sent. The handler can either
+// write a header, or just start writing.  Writing before sending a header
+// sends an implicitly empty 200 OK header.
+//
+// If the handler didn't declare a Content-Length up front, we either
+// go into chunking mode or, if the handler finishes running before
+// the chunking buffer size, we compute a Content-Length and send that
+// in the header instead.
+//
+// Likewise, if the handler didn't set a Content-Type, we sniff that
+// from the initial chunk of output.
+//
+// The Writers are wired together like:
+//
+// 1. *response (the ResponseWriter) ->
+// 2. (*response).w, a *bufio.Writer of bufferBeforeChunkingSize bytes
+// 3. chunkWriter.Writer (whose writeHeader finalizes Content-Length/Type)
+//    and which writes the chunk headers, if needed.
+// 4. conn.buf, a bufio.Writer of default (4kB) bytes
+// 5. the rwc, the net.Conn.
+//
+// TODO(bradfitz): short-circuit some of the buffering when the
+// initial header contains both a Content-Type and Content-Length.
+// Also short-circuit in (1) when the header's been sent and not in
+// chunking mode, writing directly to (4) instead, if (2) has no
+// buffered data.  More generally, we could short-circuit from (1) to
+// (3) even in chunking mode if the write size from (1) is over some
+// threshold and nothing is in (2).  The answer might be mostly making
+// bufferBeforeChunkingSize smaller and having bufio's fast-paths deal
+// with this instead.
+func (w *response) Write(data []byte) (n int, err error) {
+	return w.write(len(data), data, "")
+}
+
+func (w *response) WriteString(data string) (n int, err error) {
+	return w.write(len(data), nil, data)
+}
+
+// either dataB or dataS is non-zero.
+func (w *response) write(lenData int, dataB []byte, dataS string) (n int, err error) {
+	if w.conn.hijacked() {
+		w.conn.server.logf("http: response.Write on hijacked connection")
+		return 0, ErrHijacked
+	}
+	if !w.wroteHeader {
+		w.WriteHeader(StatusOK)
+	}
+	if lenData == 0 {
+		return 0, nil
+	}
+	if !w.bodyAllowed() {
+		return 0, ErrBodyNotAllowed
+	}
+
+	w.written += int64(lenData) // ignoring errors, for errorKludge
+	if w.contentLength != -1 && w.written > w.contentLength {
+		return 0, ErrContentLength
+	}
+	if dataB != nil {
+		return w.w.Write(dataB)
+	} else {
+		return w.w.WriteString(dataS)
+	}
+}
+
+func (w *response) finishRequest() {
+	w.handlerDone = true
+
+	if !w.wroteHeader {
+		w.WriteHeader(StatusOK)
+	}
+
+	w.w.Flush()
+	putBufioWriter(w.w)
+	w.cw.close()
+	w.conn.buf.Flush()
+
+	// Close the body (regardless of w.closeAfterReply) so we can
+	// re-use its bufio.Reader later safely.
+	w.req.Body.Close()
+
+	if w.req.MultipartForm != nil {
+		w.req.MultipartForm.RemoveAll()
+	}
+
+	if w.req.Method != "HEAD" && w.contentLength != -1 && w.bodyAllowed() && w.contentLength != w.written {
+		// Did not write enough. Avoid getting out of sync.
+		w.closeAfterReply = true
+	}
+}
+
+func (w *response) Flush() {
+	if !w.wroteHeader {
+		w.WriteHeader(StatusOK)
+	}
+	w.w.Flush()
+	w.cw.flush()
+}
+
+func (c *conn) finalFlush() {
+	if c.buf != nil {
+		c.buf.Flush()
+
+		// Steal the bufio.Reader (~4KB worth of memory) and its associated
+		// reader for a future connection.
+		putBufioReader(c.buf.Reader)
+
+		// Steal the bufio.Writer (~4KB worth of memory) and its associated
+		// writer for a future connection.
+		putBufioWriter(c.buf.Writer)
+
+		c.buf = nil
+	}
+}
+
+// Close the connection.
+func (c *conn) close() {
+	c.finalFlush()
+	if c.rwc != nil {
+		c.rwc.Close()
+		c.rwc = nil
+	}
+}
+
+// rstAvoidanceDelay is the amount of time we sleep after closing the
+// write side of a TCP connection before closing the entire socket.
+// By sleeping, we increase the chances that the client sees our FIN
+// and processes its final data before they process the subsequent RST
+// from closing a connection with known unread data.
+// This RST seems to occur mostly on BSD systems. (And Windows?)
+// This timeout is somewhat arbitrary (~latency around the planet).
+const rstAvoidanceDelay = 500 * time.Millisecond
+
+// closeWrite flushes any outstanding data and sends a FIN packet (if
+// client is connected via TCP), signalling that we're done.  We then
+// pause for a bit, hoping the client processes it before `any
+// subsequent RST.
+//
+// See http://golang.org/issue/3595
+func (c *conn) closeWriteAndWait() {
+	c.finalFlush()
+	if tcp, ok := c.rwc.(*net.TCPConn); ok {
+		tcp.CloseWrite()
+	}
+	time.Sleep(rstAvoidanceDelay)
+}
+
+// validNPN reports whether the proto is not a blacklisted Next
+// Protocol Negotiation protocol.  Empty and built-in protocol types
+// are blacklisted and can't be overridden with alternate
+// implementations.
+func validNPN(proto string) bool {
+	switch proto {
+	case "", "http/1.1", "http/1.0":
+		return false
+	}
+	return true
+}
+
+func (c *conn) setState(nc net.Conn, state ConnState) {
+	if hook := c.server.ConnState; hook != nil {
+		hook(nc, state)
+	}
+}
+
+// Serve a new connection.
+func (c *conn) serve() {
+	origConn := c.rwc // copy it before it's set nil on Close or Hijack
+	defer func() {
+		if err := recover(); err != nil {
+			const size = 64 << 10
+			buf := make([]byte, size)
+			buf = buf[:runtime.Stack(buf, false)]
+			c.server.logf("http: panic serving %v: %v\n%s", c.remoteAddr, err, buf)
+		}
+		if !c.hijacked() {
+			c.close()
+			c.setState(origConn, StateClosed)
+		}
+	}()
+
+	if tlsConn, ok := c.rwc.(*tls.Conn); ok {
+		if d := c.server.ReadTimeout; d != 0 {
+			c.rwc.SetReadDeadline(time.Now().Add(d))
+		}
+		if d := c.server.WriteTimeout; d != 0 {
+			c.rwc.SetWriteDeadline(time.Now().Add(d))
+		}
+		if err := tlsConn.Handshake(); err != nil {
+			c.server.logf("http: TLS handshake error from %s: %v", c.rwc.RemoteAddr(), err)
+			return
+		}
+		c.tlsState = new(tls.ConnectionState)
+		*c.tlsState = tlsConn.ConnectionState()
+		if proto := c.tlsState.NegotiatedProtocol; validNPN(proto) {
+			if fn := c.server.TLSNextProto[proto]; fn != nil {
+				h := initNPNRequest{tlsConn, serverHandler{c.server}}
+				fn(c.server, tlsConn, h)
+			}
+			return
+		}
+	}
+
+	for {
+		w, err := c.readRequest()
+		if c.lr.N != c.server.initialLimitedReaderSize() {
+			// If we read any bytes off the wire, we're active.
+			c.setState(c.rwc, StateActive)
+		}
+		if err != nil {
+			if err == errTooLarge {
+				// Their HTTP client may or may not be
+				// able to read this if we're
+				// responding to them and hanging up
+				// while they're still writing their
+				// request.  Undefined behavior.
+				io.WriteString(c.rwc, "HTTP/1.1 413 Request Entity Too Large\r\n\r\n")
+				c.closeWriteAndWait()
+				break
+			} else if err == io.EOF {
+				break // Don't reply
+			} else if neterr, ok := err.(net.Error); ok && neterr.Timeout() {
+				break // Don't reply
+			}
+			io.WriteString(c.rwc, "HTTP/1.1 400 Bad Request\r\n\r\n")
+			break
+		}
+
+		// Expect 100 Continue support
+		req := w.req
+		if req.expectsContinue() {
+			if req.ProtoAtLeast(1, 1) && req.ContentLength != 0 {
+				// Wrap the Body reader with one that replies on the connection
+				req.Body = &expectContinueReader{readCloser: req.Body, resp: w}
+			}
+			req.Header.Del("Expect")
+		} else if req.Header.get("Expect") != "" {
+			w.sendExpectationFailed()
+			break
+		}
+
+		// HTTP cannot have multiple simultaneous active requests.[*]
+		// Until the server replies to this request, it can't read another,
+		// so we might as well run the handler in this goroutine.
+		// [*] Not strictly true: HTTP pipelining.  We could let them all process
+		// in parallel even if their responses need to be serialized.
+		serverHandler{c.server}.ServeHTTP(w, w.req)
+		if c.hijacked() {
+			return
+		}
+		w.finishRequest()
+		if w.closeAfterReply {
+			if w.requestBodyLimitHit {
+				c.closeWriteAndWait()
+			}
+			break
+		}
+		c.setState(c.rwc, StateIdle)
+	}
+}
+
+func (w *response) sendExpectationFailed() {
+	// TODO(bradfitz): let ServeHTTP handlers handle
+	// requests with non-standard expectation[s]? Seems
+	// theoretical at best, and doesn't fit into the
+	// current ServeHTTP model anyway.  We'd need to
+	// make the ResponseWriter an optional
+	// "ExpectReplier" interface or something.
+	//
+	// For now we'll just obey RFC 2616 14.20 which says
+	// "If a server receives a request containing an
+	// Expect field that includes an expectation-
+	// extension that it does not support, it MUST
+	// respond with a 417 (Expectation Failed) status."
+	w.Header().Set("Connection", "close")
+	w.WriteHeader(StatusExpectationFailed)
+	w.finishRequest()
+}
+
+// Hijack implements the Hijacker.Hijack method. Our response is both a ResponseWriter
+// and a Hijacker.
+func (w *response) Hijack() (rwc net.Conn, buf *bufio.ReadWriter, err error) {
+	if w.wroteHeader {
+		w.cw.flush()
+	}
+	// Release the bufioWriter that writes to the chunk writer, it is not
+	// used after a connection has been hijacked.
+	rwc, buf, err = w.conn.hijack()
+	if err == nil {
+		putBufioWriter(w.w)
+		w.w = nil
+	}
+	return rwc, buf, err
+}
+
+func (w *response) CloseNotify() <-chan bool {
+	return w.conn.closeNotify()
+}
+
+// The HandlerFunc type is an adapter to allow the use of
+// ordinary functions as HTTP handlers.  If f is a function
+// with the appropriate signature, HandlerFunc(f) is a
+// Handler object that calls f.
+type HandlerFunc func(ResponseWriter, *Request)
+
+// ServeHTTP calls f(w, r).
+func (f HandlerFunc) ServeHTTP(w ResponseWriter, r *Request) {
+	f(w, r)
+}
+
+// Helper handlers
+
+// Error replies to the request with the specified error message and HTTP code.
+// The error message should be plain text.
+func Error(w ResponseWriter, error string, code int) {
+	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+	w.WriteHeader(code)
+	fmt.Fprintln(w, error)
+}
+
+// NotFound replies to the request with an HTTP 404 not found error.
+func NotFound(w ResponseWriter, r *Request) { Error(w, "404 page not found", StatusNotFound) }
+
+// NotFoundHandler returns a simple request handler
+// that replies to each request with a ``404 page not found'' reply.
+func NotFoundHandler() Handler { return HandlerFunc(NotFound) }
+
+// StripPrefix returns a handler that serves HTTP requests
+// by removing the given prefix from the request URL's Path
+// and invoking the handler h. StripPrefix handles a
+// request for a path that doesn't begin with prefix by
+// replying with an HTTP 404 not found error.
+func StripPrefix(prefix string, h Handler) Handler {
+	if prefix == "" {
+		return h
+	}
+	return HandlerFunc(func(w ResponseWriter, r *Request) {
+		if p := strings.TrimPrefix(r.URL.Path, prefix); len(p) < len(r.URL.Path) {
+			r.URL.Path = p
+			h.ServeHTTP(w, r)
+		} else {
+			NotFound(w, r)
+		}
+	})
+}
+
+// Redirect replies to the request with a redirect to url,
+// which may be a path relative to the request path.
+func Redirect(w ResponseWriter, r *Request, urlStr string, code int) {
+	if u, err := url.Parse(urlStr); err == nil {
+		// If url was relative, make absolute by
+		// combining with request path.
+		// The browser would probably do this for us,
+		// but doing it ourselves is more reliable.
+
+		// NOTE(rsc): RFC 2616 says that the Location
+		// line must be an absolute URI, like
+		// "http://www.google.com/redirect/",
+		// not a path like "/redirect/".
+		// Unfortunately, we don't know what to
+		// put in the host name section to get the
+		// client to connect to us again, so we can't
+		// know the right absolute URI to send back.
+		// Because of this problem, no one pays attention
+		// to the RFC; they all send back just a new path.
+		// So do we.
+		oldpath := r.URL.Path
+		if oldpath == "" { // should not happen, but avoid a crash if it does
+			oldpath = "/"
+		}
+		if u.Scheme == "" {
+			// no leading http://server
+			if urlStr == "" || urlStr[0] != '/' {
+				// make relative path absolute
+				olddir, _ := path.Split(oldpath)
+				urlStr = olddir + urlStr
+			}
+
+			var query string
+			if i := strings.Index(urlStr, "?"); i != -1 {
+				urlStr, query = urlStr[:i], urlStr[i:]
+			}
+
+			// clean up but preserve trailing slash
+			trailing := strings.HasSuffix(urlStr, "/")
+			urlStr = path.Clean(urlStr)
+			if trailing && !strings.HasSuffix(urlStr, "/") {
+				urlStr += "/"
+			}
+			urlStr += query
+		}
+	}
+
+	w.Header().Set("Location", urlStr)
+	w.WriteHeader(code)
+
+	// RFC2616 recommends that a short note "SHOULD" be included in the
+	// response because older user agents may not understand 301/307.
+	// Shouldn't send the response for POST or HEAD; that leaves GET.
+	if r.Method == "GET" {
+		note := "<a href=\"" + htmlEscape(urlStr) + "\">" + statusText[code] + "</a>.\n"
+		fmt.Fprintln(w, note)
+	}
+}
+
+var htmlReplacer = strings.NewReplacer(
+	"&", "&amp;",
+	"<", "&lt;",
+	">", "&gt;",
+	// "&#34;" is shorter than "&quot;".
+	`"`, "&#34;",
+	// "&#39;" is shorter than "&apos;" and apos was not in HTML until HTML5.
+	"'", "&#39;",
+)
+
+func htmlEscape(s string) string {
+	return htmlReplacer.Replace(s)
+}
+
+// Redirect to a fixed URL
+type redirectHandler struct {
+	url  string
+	code int
+}
+
+func (rh *redirectHandler) ServeHTTP(w ResponseWriter, r *Request) {
+	Redirect(w, r, rh.url, rh.code)
+}
+
+// RedirectHandler returns a request handler that redirects
+// each request it receives to the given url using the given
+// status code.
+func RedirectHandler(url string, code int) Handler {
+	return &redirectHandler{url, code}
+}
+
+// ServeMux is an HTTP request multiplexer.
+// It matches the URL of each incoming request against a list of registered
+// patterns and calls the handler for the pattern that
+// most closely matches the URL.
+//
+// Patterns name fixed, rooted paths, like "/favicon.ico",
+// or rooted subtrees, like "/images/" (note the trailing slash).
+// Longer patterns take precedence over shorter ones, so that
+// if there are handlers registered for both "/images/"
+// and "/images/thumbnails/", the latter handler will be
+// called for paths beginning "/images/thumbnails/" and the
+// former will receive requests for any other paths in the
+// "/images/" subtree.
+//
+// Note that since a pattern ending in a slash names a rooted subtree,
+// the pattern "/" matches all paths not matched by other registered
+// patterns, not just the URL with Path == "/".
+//
+// Patterns may optionally begin with a host name, restricting matches to
+// URLs on that host only.  Host-specific patterns take precedence over
+// general patterns, so that a handler might register for the two patterns
+// "/codesearch" and "codesearch.google.com/" without also taking over
+// requests for "http://www.google.com/".
+//
+// ServeMux also takes care of sanitizing the URL request path,
+// redirecting any request containing . or .. elements to an
+// equivalent .- and ..-free URL.
+type ServeMux struct {
+	mu    sync.RWMutex
+	m     map[string]muxEntry
+	hosts bool // whether any patterns contain hostnames
+}
+
+type muxEntry struct {
+	explicit bool
+	h        Handler
+	pattern  string
+}
+
+// NewServeMux allocates and returns a new ServeMux.
+func NewServeMux() *ServeMux { return &ServeMux{m: make(map[string]muxEntry)} }
+
+// DefaultServeMux is the default ServeMux used by Serve.
+var DefaultServeMux = NewServeMux()
+
+// Does path match pattern?
+func pathMatch(pattern, path string) bool {
+	if len(pattern) == 0 {
+		// should not happen
+		return false
+	}
+	n := len(pattern)
+	if pattern[n-1] != '/' {
+		return pattern == path
+	}
+	return len(path) >= n && path[0:n] == pattern
+}
+
+// Return the canonical path for p, eliminating . and .. elements.
+func cleanPath(p string) string {
+	if p == "" {
+		return "/"
+	}
+	if p[0] != '/' {
+		p = "/" + p
+	}
+	np := path.Clean(p)
+	// path.Clean removes trailing slash except for root;
+	// put the trailing slash back if necessary.
+	if p[len(p)-1] == '/' && np != "/" {
+		np += "/"
+	}
+	return np
+}
+
+// Find a handler on a handler map given a path string
+// Most-specific (longest) pattern wins
+func (mux *ServeMux) match(path string) (h Handler, pattern string) {
+	var n = 0
+	for k, v := range mux.m {
+		if !pathMatch(k, path) {
+			continue
+		}
+		if h == nil || len(k) > n {
+			n = len(k)
+			h = v.h
+			pattern = v.pattern
+		}
+	}
+	return
+}
+
+// Handler returns the handler to use for the given request,
+// consulting r.Method, r.Host, and r.URL.Path. It always returns
+// a non-nil handler. If the path is not in its canonical form, the
+// handler will be an internally-generated handler that redirects
+// to the canonical path.
+//
+// Handler also returns the registered pattern that matches the
+// request or, in the case of internally-generated redirects,
+// the pattern that will match after following the redirect.
+//
+// If there is no registered handler that applies to the request,
+// Handler returns a ``page not found'' handler and an empty pattern.
+func (mux *ServeMux) Handler(r *Request) (h Handler, pattern string) {
+	if r.Method != "CONNECT" {
+		if p := cleanPath(r.URL.Path); p != r.URL.Path {
+			_, pattern = mux.handler(r.Host, p)
+			url := *r.URL
+			url.Path = p
+			return RedirectHandler(url.String(), StatusMovedPermanently), pattern
+		}
+	}
+
+	return mux.handler(r.Host, r.URL.Path)
+}
+
+// handler is the main implementation of Handler.
+// The path is known to be in canonical form, except for CONNECT methods.
+func (mux *ServeMux) handler(host, path string) (h Handler, pattern string) {
+	mux.mu.RLock()
+	defer mux.mu.RUnlock()
+
+	// Host-specific pattern takes precedence over generic ones
+	if mux.hosts {
+		h, pattern = mux.match(host + path)
+	}
+	if h == nil {
+		h, pattern = mux.match(path)
+	}
+	if h == nil {
+		h, pattern = NotFoundHandler(), ""
+	}
+	return
+}
+
+// ServeHTTP dispatches the request to the handler whose
+// pattern most closely matches the request URL.
+func (mux *ServeMux) ServeHTTP(w ResponseWriter, r *Request) {
+	if r.RequestURI == "*" {
+		if r.ProtoAtLeast(1, 1) {
+			w.Header().Set("Connection", "close")
+		}
+		w.WriteHeader(StatusBadRequest)
+		return
+	}
+	h, _ := mux.Handler(r)
+	h.ServeHTTP(w, r)
+}
+
+// Handle registers the handler for the given pattern.
+// If a handler already exists for pattern, Handle panics.
+func (mux *ServeMux) Handle(pattern string, handler Handler) {
+	mux.mu.Lock()
+	defer mux.mu.Unlock()
+
+	if pattern == "" {
+		panic("http: invalid pattern " + pattern)
+	}
+	if handler == nil {
+		panic("http: nil handler")
+	}
+	if mux.m[pattern].explicit {
+		panic("http: multiple registrations for " + pattern)
+	}
+
+	mux.m[pattern] = muxEntry{explicit: true, h: handler, pattern: pattern}
+
+	if pattern[0] != '/' {
+		mux.hosts = true
+	}
+
+	// Helpful behavior:
+	// If pattern is /tree/, insert an implicit permanent redirect for /tree.
+	// It can be overridden by an explicit registration.
+	n := len(pattern)
+	if n > 0 && pattern[n-1] == '/' && !mux.m[pattern[0:n-1]].explicit {
+		// If pattern contains a host name, strip it and use remaining
+		// path for redirect.
+		path := pattern
+		if pattern[0] != '/' {
+			// In pattern, at least the last character is a '/', so
+			// strings.Index can't be -1.
+			path = pattern[strings.Index(pattern, "/"):]
+		}
+		mux.m[pattern[0:n-1]] = muxEntry{h: RedirectHandler(path, StatusMovedPermanently), pattern: pattern}
+	}
+}
+
+// HandleFunc registers the handler function for the given pattern.
+func (mux *ServeMux) HandleFunc(pattern string, handler func(ResponseWriter, *Request)) {
+	mux.Handle(pattern, HandlerFunc(handler))
+}
+
+// Handle registers the handler for the given pattern
+// in the DefaultServeMux.
+// The documentation for ServeMux explains how patterns are matched.
+func Handle(pattern string, handler Handler) { DefaultServeMux.Handle(pattern, handler) }
+
+// HandleFunc registers the handler function for the given pattern
+// in the DefaultServeMux.
+// The documentation for ServeMux explains how patterns are matched.
+func HandleFunc(pattern string, handler func(ResponseWriter, *Request)) {
+	DefaultServeMux.HandleFunc(pattern, handler)
+}
+
+// Serve accepts incoming HTTP connections on the listener l,
+// creating a new service goroutine for each.  The service goroutines
+// read requests and then call handler to reply to them.
+// Handler is typically nil, in which case the DefaultServeMux is used.
+func Serve(l net.Listener, handler Handler) error {
+	srv := &Server{Handler: handler}
+	return srv.Serve(l)
+}
+
+// A Server defines parameters for running an HTTP server.
+// The zero value for Server is a valid configuration.
+type Server struct {
+	Addr           string        // TCP address to listen on, ":http" if empty
+	Handler        Handler       // handler to invoke, http.DefaultServeMux if nil
+	ReadTimeout    time.Duration // maximum duration before timing out read of the request
+	WriteTimeout   time.Duration // maximum duration before timing out write of the response
+	MaxHeaderBytes int           // maximum size of request headers, DefaultMaxHeaderBytes if 0
+	TLSConfig      *tls.Config   // optional TLS config, used by ListenAndServeTLS
+
+	// TLSNextProto optionally specifies a function to take over
+	// ownership of the provided TLS connection when an NPN
+	// protocol upgrade has occurred.  The map key is the protocol
+	// name negotiated. The Handler argument should be used to
+	// handle HTTP requests and will initialize the Request's TLS
+	// and RemoteAddr if not already set.  The connection is
+	// automatically closed when the function returns.
+	TLSNextProto map[string]func(*Server, *tls.Conn, Handler)
+
+	// ConnState specifies an optional callback function that is
+	// called when a client connection changes state. See the
+	// ConnState type and associated constants for details.
+	ConnState func(net.Conn, ConnState)
+
+	// ErrorLog specifies an optional logger for errors accepting
+	// connections and unexpected behavior from handlers.
+	// If nil, logging goes to os.Stderr via the log package's
+	// standard logger.
+	ErrorLog *log.Logger
+
+	disableKeepAlives int32 // accessed atomically.
+}
+
+// A ConnState represents the state of a client connection to a server.
+// It's used by the optional Server.ConnState hook.
+type ConnState int
+
+const (
+	// StateNew represents a new connection that is expected to
+	// send a request immediately. Connections begin at this
+	// state and then transition to either StateActive or
+	// StateClosed.
+	StateNew ConnState = iota
+
+	// StateActive represents a connection that has read 1 or more
+	// bytes of a request. The Server.ConnState hook for
+	// StateActive fires before the request has entered a handler
+	// and doesn't fire again until the request has been
+	// handled. After the request is handled, the state
+	// transitions to StateClosed, StateHijacked, or StateIdle.
+	StateActive
+
+	// StateIdle represents a connection that has finished
+	// handling a request and is in the keep-alive state, waiting
+	// for a new request. Connections transition from StateIdle
+	// to either StateActive or StateClosed.
+	StateIdle
+
+	// StateHijacked represents a hijacked connection.
+	// This is a terminal state. It does not transition to StateClosed.
+	StateHijacked
+
+	// StateClosed represents a closed connection.
+	// This is a terminal state. Hijacked connections do not
+	// transition to StateClosed.
+	StateClosed
+)
+
+var stateName = map[ConnState]string{
+	StateNew:      "new",
+	StateActive:   "active",
+	StateIdle:     "idle",
+	StateHijacked: "hijacked",
+	StateClosed:   "closed",
+}
+
+func (c ConnState) String() string {
+	return stateName[c]
+}
+
+// serverHandler delegates to either the server's Handler or
+// DefaultServeMux and also handles "OPTIONS *" requests.
+type serverHandler struct {
+	srv *Server
+}
+
+func (sh serverHandler) ServeHTTP(rw ResponseWriter, req *Request) {
+	handler := sh.srv.Handler
+	if handler == nil {
+		handler = DefaultServeMux
+	}
+	if req.RequestURI == "*" && req.Method == "OPTIONS" {
+		handler = globalOptionsHandler{}
+	}
+	handler.ServeHTTP(rw, req)
+}
+
+// ListenAndServe listens on the TCP network address srv.Addr and then
+// calls Serve to handle requests on incoming connections.  If
+// srv.Addr is blank, ":http" is used.
+func (srv *Server) ListenAndServe() error {
+	addr := srv.Addr
+	if addr == "" {
+		addr = ":http"
+	}
+	ln, err := net.Listen("tcp", addr)
+	if err != nil {
+		return err
+	}
+	return srv.Serve(tcpKeepAliveListener{ln.(*net.TCPListener)})
+}
+
+// Serve accepts incoming connections on the Listener l, creating a
+// new service goroutine for each.  The service goroutines read requests and
+// then call srv.Handler to reply to them.
+func (srv *Server) Serve(l net.Listener) error {
+	defer l.Close()
+	var tempDelay time.Duration // how long to sleep on accept failure
+	for {
+		rw, e := l.Accept()
+		if e != nil {
+			if ne, ok := e.(net.Error); ok && ne.Temporary() {
+				if tempDelay == 0 {
+					tempDelay = 5 * time.Millisecond
+				} else {
+					tempDelay *= 2
+				}
+				if max := 1 * time.Second; tempDelay > max {
+					tempDelay = max
+				}
+				srv.logf("http: Accept error: %v; retrying in %v", e, tempDelay)
+				time.Sleep(tempDelay)
+				continue
+			}
+			return e
+		}
+		tempDelay = 0
+		c, err := srv.newConn(rw)
+		if err != nil {
+			continue
+		}
+		c.setState(c.rwc, StateNew) // before Serve can return
+		go c.serve()
+	}
+}
+
+func (s *Server) doKeepAlives() bool {
+	return atomic.LoadInt32(&s.disableKeepAlives) == 0
+}
+
+// SetKeepAlivesEnabled controls whether HTTP keep-alives are enabled.
+// By default, keep-alives are always enabled. Only very
+// resource-constrained environments or servers in the process of
+// shutting down should disable them.
+func (s *Server) SetKeepAlivesEnabled(v bool) {
+	if v {
+		atomic.StoreInt32(&s.disableKeepAlives, 0)
+	} else {
+		atomic.StoreInt32(&s.disableKeepAlives, 1)
+	}
+}
+
+func (s *Server) logf(format string, args ...interface{}) {
+	if s.ErrorLog != nil {
+		s.ErrorLog.Printf(format, args...)
+	} else {
+		log.Printf(format, args...)
+	}
+}
+
+// ListenAndServe listens on the TCP network address addr
+// and then calls Serve with handler to handle requests
+// on incoming connections.  Handler is typically nil,
+// in which case the DefaultServeMux is used.
+//
+// A trivial example server is:
+//
+//	package main
+//
+//	import (
+//		"io"
+//		"net/http"
+//		"log"
+//	)
+//
+//	// hello world, the web server
+//	func HelloServer(w http.ResponseWriter, req *http.Request) {
+//		io.WriteString(w, "hello, world!\n")
+//	}
+//
+//	func main() {
+//		http.HandleFunc("/hello", HelloServer)
+//		err := http.ListenAndServe(":12345", nil)
+//		if err != nil {
+//			log.Fatal("ListenAndServe: ", err)
+//		}
+//	}
+func ListenAndServe(addr string, handler Handler) error {
+	server := &Server{Addr: addr, Handler: handler}
+	return server.ListenAndServe()
+}
+
+// ListenAndServeTLS acts identically to ListenAndServe, except that it
+// expects HTTPS connections. Additionally, files containing a certificate and
+// matching private key for the server must be provided. If the certificate
+// is signed by a certificate authority, the certFile should be the concatenation
+// of the server's certificate followed by the CA's certificate.
+//
+// A trivial example server is:
+//
+//	import (
+//		"log"
+//		"net/http"
+//	)
+//
+//	func handler(w http.ResponseWriter, req *http.Request) {
+//		w.Header().Set("Content-Type", "text/plain")
+//		w.Write([]byte("This is an example server.\n"))
+//	}
+//
+//	func main() {
+//		http.HandleFunc("/", handler)
+//		log.Printf("About to listen on 10443. Go to https://127.0.0.1:10443/")
+//		err := http.ListenAndServeTLS(":10443", "cert.pem", "key.pem", nil)
+//		if err != nil {
+//			log.Fatal(err)
+//		}
+//	}
+//
+// One can use generate_cert.go in crypto/tls to generate cert.pem and key.pem.
+func ListenAndServeTLS(addr string, certFile string, keyFile string, handler Handler) error {
+	server := &Server{Addr: addr, Handler: handler}
+	return server.ListenAndServeTLS(certFile, keyFile)
+}
+
+// ListenAndServeTLS listens on the TCP network address srv.Addr and
+// then calls Serve to handle requests on incoming TLS connections.
+//
+// Filenames containing a certificate and matching private key for
+// the server must be provided. If the certificate is signed by a
+// certificate authority, the certFile should be the concatenation
+// of the server's certificate followed by the CA's certificate.
+//
+// If srv.Addr is blank, ":https" is used.
+func (srv *Server) ListenAndServeTLS(certFile, keyFile string) error {
+	addr := srv.Addr
+	if addr == "" {
+		addr = ":https"
+	}
+	config := &tls.Config{}
+	if srv.TLSConfig != nil {
+		*config = *srv.TLSConfig
+	}
+	if config.NextProtos == nil {
+		config.NextProtos = []string{"http/1.1"}
+	}
+
+	var err error
+	config.Certificates = make([]tls.Certificate, 1)
+	config.Certificates[0], err = tls.LoadX509KeyPair(certFile, keyFile)
+	if err != nil {
+		return err
+	}
+
+	ln, err := net.Listen("tcp", addr)
+	if err != nil {
+		return err
+	}
+
+	tlsListener := tls.NewListener(tcpKeepAliveListener{ln.(*net.TCPListener)}, config)
+	return srv.Serve(tlsListener)
+}
+
+// TimeoutHandler returns a Handler that runs h with the given time limit.
+//
+// The new Handler calls h.ServeHTTP to handle each request, but if a
+// call runs for longer than its time limit, the handler responds with
+// a 503 Service Unavailable error and the given message in its body.
+// (If msg is empty, a suitable default message will be sent.)
+// After such a timeout, writes by h to its ResponseWriter will return
+// ErrHandlerTimeout.
+func TimeoutHandler(h Handler, dt time.Duration, msg string) Handler {
+	f := func() <-chan time.Time {
+		return time.After(dt)
+	}
+	return &timeoutHandler{h, f, msg}
+}
+
+// ErrHandlerTimeout is returned on ResponseWriter Write calls
+// in handlers which have timed out.
+var ErrHandlerTimeout = errors.New("http: Handler timeout")
+
+type timeoutHandler struct {
+	handler Handler
+	timeout func() <-chan time.Time // returns channel producing a timeout
+	body    string
+}
+
+func (h *timeoutHandler) errorBody() string {
+	if h.body != "" {
+		return h.body
+	}
+	return "<html><head><title>Timeout</title></head><body><h1>Timeout</h1></body></html>"
+}
+
+func (h *timeoutHandler) ServeHTTP(w ResponseWriter, r *Request) {
+	done := make(chan bool, 1)
+	tw := &timeoutWriter{w: w}
+	go func() {
+		h.handler.ServeHTTP(tw, r)
+		done <- true
+	}()
+	select {
+	case <-done:
+		return
+	case <-h.timeout():
+		tw.mu.Lock()
+		defer tw.mu.Unlock()
+		if !tw.wroteHeader {
+			tw.w.WriteHeader(StatusServiceUnavailable)
+			tw.w.Write([]byte(h.errorBody()))
+		}
+		tw.timedOut = true
+	}
+}
+
+type timeoutWriter struct {
+	w ResponseWriter
+
+	mu          sync.Mutex
+	timedOut    bool
+	wroteHeader bool
+}
+
+func (tw *timeoutWriter) Header() Header {
+	return tw.w.Header()
+}
+
+func (tw *timeoutWriter) Write(p []byte) (int, error) {
+	tw.mu.Lock()
+	timedOut := tw.timedOut
+	tw.mu.Unlock()
+	if timedOut {
+		return 0, ErrHandlerTimeout
+	}
+	return tw.w.Write(p)
+}
+
+func (tw *timeoutWriter) WriteHeader(code int) {
+	tw.mu.Lock()
+	if tw.timedOut || tw.wroteHeader {
+		tw.mu.Unlock()
+		return
+	}
+	tw.wroteHeader = true
+	tw.mu.Unlock()
+	tw.w.WriteHeader(code)
+}
+
+// tcpKeepAliveListener sets TCP keep-alive timeouts on accepted
+// connections. It's used by ListenAndServe and ListenAndServeTLS so
+// dead TCP connections (e.g. closing laptop mid-download) eventually
+// go away.
+type tcpKeepAliveListener struct {
+	*net.TCPListener
+}
+
+func (ln tcpKeepAliveListener) Accept() (c net.Conn, err error) {
+	tc, err := ln.AcceptTCP()
+	if err != nil {
+		return
+	}
+	tc.SetKeepAlive(true)
+	tc.SetKeepAlivePeriod(3 * time.Minute)
+	return tc, nil
+}
+
+// globalOptionsHandler responds to "OPTIONS *" requests.
+type globalOptionsHandler struct{}
+
+func (globalOptionsHandler) ServeHTTP(w ResponseWriter, r *Request) {
+	w.Header().Set("Content-Length", "0")
+	if r.ContentLength != 0 {
+		// Read up to 4KB of OPTIONS body (as mentioned in the
+		// spec as being reserved for future use), but anything
+		// over that is considered a waste of server resources
+		// (or an attack) and we abort and close the connection,
+		// courtesy of MaxBytesReader's EOF behavior.
+		mb := MaxBytesReader(w, r.Body, 4<<10)
+		io.Copy(ioutil.Discard, mb)
+	}
+}
+
+type eofReaderWithWriteTo struct{}
+
+func (eofReaderWithWriteTo) WriteTo(io.Writer) (int64, error) { return 0, nil }
+func (eofReaderWithWriteTo) Read([]byte) (int, error)         { return 0, io.EOF }
+
+// eofReader is a non-nil io.ReadCloser that always returns EOF.
+// It has a WriteTo method so io.Copy won't need a buffer.
+var eofReader = &struct {
+	eofReaderWithWriteTo
+	io.Closer
+}{
+	eofReaderWithWriteTo{},
+	ioutil.NopCloser(nil),
+}
+
+// Verify that an io.Copy from an eofReader won't require a buffer.
+var _ io.WriterTo = eofReader
+
+// initNPNRequest is an HTTP handler that initializes certain
+// uninitialized fields in its *Request. Such partially-initialized
+// Requests come from NPN protocol handlers.
+type initNPNRequest struct {
+	c *tls.Conn
+	h serverHandler
+}
+
+func (h initNPNRequest) ServeHTTP(rw ResponseWriter, req *Request) {
+	if req.TLS == nil {
+		req.TLS = &tls.ConnectionState{}
+		*req.TLS = h.c.ConnectionState()
+	}
+	if req.Body == nil {
+		req.Body = eofReader
+	}
+	if req.RemoteAddr == "" {
+		req.RemoteAddr = h.c.RemoteAddr().String()
+	}
+	h.h.ServeHTTP(rw, req)
+}
+
+// loggingConn is used for debugging.
+type loggingConn struct {
+	name string
+	net.Conn
+}
+
+var (
+	uniqNameMu   sync.Mutex
+	uniqNameNext = make(map[string]int)
+)
+
+func newLoggingConn(baseName string, c net.Conn) net.Conn {
+	uniqNameMu.Lock()
+	defer uniqNameMu.Unlock()
+	uniqNameNext[baseName]++
+	return &loggingConn{
+		name: fmt.Sprintf("%s-%d", baseName, uniqNameNext[baseName]),
+		Conn: c,
+	}
+}
+
+func (c *loggingConn) Write(p []byte) (n int, err error) {
+	log.Printf("%s.Write(%d) = ....", c.name, len(p))
+	n, err = c.Conn.Write(p)
+	log.Printf("%s.Write(%d) = %d, %v", c.name, len(p), n, err)
+	return
+}
+
+func (c *loggingConn) Read(p []byte) (n int, err error) {
+	log.Printf("%s.Read(%d) = ....", c.name, len(p))
+	n, err = c.Conn.Read(p)
+	log.Printf("%s.Read(%d) = %d, %v", c.name, len(p), n, err)
+	return
+}
+
+func (c *loggingConn) Close() (err error) {
+	log.Printf("%s.Close() = ...", c.name)
+	err = c.Conn.Close()
+	log.Printf("%s.Close() = %v", c.name, err)
+	return
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/http/sniff.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/sniff.go
new file mode 100644
index 000000000..68f519b05
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/sniff.go
@@ -0,0 +1,214 @@
+// Copyright 2011 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package http
+
+import (
+	"bytes"
+	"encoding/binary"
+)
+
+// The algorithm uses at most sniffLen bytes to make its decision.
+const sniffLen = 512
+
+// DetectContentType implements the algorithm described
+// at http://mimesniff.spec.whatwg.org/ to determine the
+// Content-Type of the given data.  It considers at most the
+// first 512 bytes of data.  DetectContentType always returns
+// a valid MIME type: if it cannot determine a more specific one, it
+// returns "application/octet-stream".
+func DetectContentType(data []byte) string {
+	if len(data) > sniffLen {
+		data = data[:sniffLen]
+	}
+
+	// Index of the first non-whitespace byte in data.
+	firstNonWS := 0
+	for ; firstNonWS < len(data) && isWS(data[firstNonWS]); firstNonWS++ {
+	}
+
+	for _, sig := range sniffSignatures {
+		if ct := sig.match(data, firstNonWS); ct != "" {
+			return ct
+		}
+	}
+
+	return "application/octet-stream" // fallback
+}
+
+func isWS(b byte) bool {
+	return bytes.IndexByte([]byte("\t\n\x0C\r "), b) != -1
+}
+
+type sniffSig interface {
+	// match returns the MIME type of the data, or "" if unknown.
+	match(data []byte, firstNonWS int) string
+}
+
+// Data matching the table in section 6.
+var sniffSignatures = []sniffSig{
+	htmlSig("<!DOCTYPE HTML"),
+	htmlSig("<HTML"),
+	htmlSig("<HEAD"),
+	htmlSig("<SCRIPT"),
+	htmlSig("<IFRAME"),
+	htmlSig("<H1"),
+	htmlSig("<DIV"),
+	htmlSig("<FONT"),
+	htmlSig("<TABLE"),
+	htmlSig("<A"),
+	htmlSig("<STYLE"),
+	htmlSig("<TITLE"),
+	htmlSig("<B"),
+	htmlSig("<BODY"),
+	htmlSig("<BR"),
+	htmlSig("<P"),
+	htmlSig("<!--"),
+
+	&maskedSig{mask: []byte("\xFF\xFF\xFF\xFF\xFF"), pat: []byte("<?xml"), skipWS: true, ct: "text/xml; charset=utf-8"},
+
+	&exactSig{[]byte("%PDF-"), "application/pdf"},
+	&exactSig{[]byte("%!PS-Adobe-"), "application/postscript"},
+
+	// UTF BOMs.
+	&maskedSig{mask: []byte("\xFF\xFF\x00\x00"), pat: []byte("\xFE\xFF\x00\x00"), ct: "text/plain; charset=utf-16be"},
+	&maskedSig{mask: []byte("\xFF\xFF\x00\x00"), pat: []byte("\xFF\xFE\x00\x00"), ct: "text/plain; charset=utf-16le"},
+	&maskedSig{mask: []byte("\xFF\xFF\xFF\x00"), pat: []byte("\xEF\xBB\xBF\x00"), ct: "text/plain; charset=utf-8"},
+
+	&exactSig{[]byte("GIF87a"), "image/gif"},
+	&exactSig{[]byte("GIF89a"), "image/gif"},
+	&exactSig{[]byte("\x89\x50\x4E\x47\x0D\x0A\x1A\x0A"), "image/png"},
+	&exactSig{[]byte("\xFF\xD8\xFF"), "image/jpeg"},
+	&exactSig{[]byte("BM"), "image/bmp"},
+	&maskedSig{
+		mask: []byte("\xFF\xFF\xFF\xFF\x00\x00\x00\x00\xFF\xFF\xFF\xFF\xFF\xFF"),
+		pat:  []byte("RIFF\x00\x00\x00\x00WEBPVP"),
+		ct:   "image/webp",
+	},
+	&exactSig{[]byte("\x00\x00\x01\x00"), "image/vnd.microsoft.icon"},
+	&exactSig{[]byte("\x4F\x67\x67\x53\x00"), "application/ogg"},
+	&maskedSig{
+		mask: []byte("\xFF\xFF\xFF\xFF\x00\x00\x00\x00\xFF\xFF\xFF\xFF"),
+		pat:  []byte("RIFF\x00\x00\x00\x00WAVE"),
+		ct:   "audio/wave",
+	},
+	&exactSig{[]byte("\x1A\x45\xDF\xA3"), "video/webm"},
+	&exactSig{[]byte("\x52\x61\x72\x20\x1A\x07\x00"), "application/x-rar-compressed"},
+	&exactSig{[]byte("\x50\x4B\x03\x04"), "application/zip"},
+	&exactSig{[]byte("\x1F\x8B\x08"), "application/x-gzip"},
+
+	// TODO(dsymonds): Re-enable this when the spec is sorted w.r.t. MP4.
+	//mp4Sig(0),
+
+	textSig(0), // should be last
+}
+
+type exactSig struct {
+	sig []byte
+	ct  string
+}
+
+func (e *exactSig) match(data []byte, firstNonWS int) string {
+	if bytes.HasPrefix(data, e.sig) {
+		return e.ct
+	}
+	return ""
+}
+
+type maskedSig struct {
+	mask, pat []byte
+	skipWS    bool
+	ct        string
+}
+
+func (m *maskedSig) match(data []byte, firstNonWS int) string {
+	if m.skipWS {
+		data = data[firstNonWS:]
+	}
+	if len(data) < len(m.mask) {
+		return ""
+	}
+	for i, mask := range m.mask {
+		db := data[i] & mask
+		if db != m.pat[i] {
+			return ""
+		}
+	}
+	return m.ct
+}
+
+type htmlSig []byte
+
+func (h htmlSig) match(data []byte, firstNonWS int) string {
+	data = data[firstNonWS:]
+	if len(data) < len(h)+1 {
+		return ""
+	}
+	for i, b := range h {
+		db := data[i]
+		if 'A' <= b && b <= 'Z' {
+			db &= 0xDF
+		}
+		if b != db {
+			return ""
+		}
+	}
+	// Next byte must be space or right angle bracket.
+	if db := data[len(h)]; db != ' ' && db != '>' {
+		return ""
+	}
+	return "text/html; charset=utf-8"
+}
+
+type mp4Sig int
+
+func (mp4Sig) match(data []byte, firstNonWS int) string {
+	// c.f. section 6.1.
+	if len(data) < 8 {
+		return ""
+	}
+	boxSize := int(binary.BigEndian.Uint32(data[:4]))
+	if boxSize%4 != 0 || len(data) < boxSize {
+		return ""
+	}
+	if !bytes.Equal(data[4:8], []byte("ftyp")) {
+		return ""
+	}
+	for st := 8; st < boxSize; st += 4 {
+		if st == 12 {
+			// minor version number
+			continue
+		}
+		seg := string(data[st : st+3])
+		switch seg {
+		case "mp4", "iso", "M4V", "M4P", "M4B":
+			return "video/mp4"
+			/* The remainder are not in the spec.
+			case "M4A":
+				return "audio/mp4"
+			case "3gp":
+				return "video/3gpp"
+			case "jp2":
+				return "image/jp2" // JPEG 2000
+			*/
+		}
+	}
+	return ""
+}
+
+type textSig int
+
+func (textSig) match(data []byte, firstNonWS int) string {
+	// c.f. section 5, step 4.
+	for _, b := range data[firstNonWS:] {
+		switch {
+		case 0x00 <= b && b <= 0x08,
+			b == 0x0B,
+			0x0E <= b && b <= 0x1A,
+			0x1C <= b && b <= 0x1F:
+			return ""
+		}
+	}
+	return "text/plain; charset=utf-8"
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/http/status.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/status.go
new file mode 100644
index 000000000..d253bd5cb
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/status.go
@@ -0,0 +1,120 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package http
+
+// HTTP status codes, defined in RFC 2616.
+const (
+	StatusContinue           = 100
+	StatusSwitchingProtocols = 101
+
+	StatusOK                   = 200
+	StatusCreated              = 201
+	StatusAccepted             = 202
+	StatusNonAuthoritativeInfo = 203
+	StatusNoContent            = 204
+	StatusResetContent         = 205
+	StatusPartialContent       = 206
+
+	StatusMultipleChoices   = 300
+	StatusMovedPermanently  = 301
+	StatusFound             = 302
+	StatusSeeOther          = 303
+	StatusNotModified       = 304
+	StatusUseProxy          = 305
+	StatusTemporaryRedirect = 307
+
+	StatusBadRequest                   = 400
+	StatusUnauthorized                 = 401
+	StatusPaymentRequired              = 402
+	StatusForbidden                    = 403
+	StatusNotFound                     = 404
+	StatusMethodNotAllowed             = 405
+	StatusNotAcceptable                = 406
+	StatusProxyAuthRequired            = 407
+	StatusRequestTimeout               = 408
+	StatusConflict                     = 409
+	StatusGone                         = 410
+	StatusLengthRequired               = 411
+	StatusPreconditionFailed           = 412
+	StatusRequestEntityTooLarge        = 413
+	StatusRequestURITooLong            = 414
+	StatusUnsupportedMediaType         = 415
+	StatusRequestedRangeNotSatisfiable = 416
+	StatusExpectationFailed            = 417
+	StatusTeapot                       = 418
+
+	StatusInternalServerError     = 500
+	StatusNotImplemented          = 501
+	StatusBadGateway              = 502
+	StatusServiceUnavailable      = 503
+	StatusGatewayTimeout          = 504
+	StatusHTTPVersionNotSupported = 505
+
+	// New HTTP status codes from RFC 6585. Not exported yet in Go 1.1.
+	// See discussion at https://codereview.appspot.com/7678043/
+	statusPreconditionRequired          = 428
+	statusTooManyRequests               = 429
+	statusRequestHeaderFieldsTooLarge   = 431
+	statusNetworkAuthenticationRequired = 511
+)
+
+var statusText = map[int]string{
+	StatusContinue:           "Continue",
+	StatusSwitchingProtocols: "Switching Protocols",
+
+	StatusOK:                   "OK",
+	StatusCreated:              "Created",
+	StatusAccepted:             "Accepted",
+	StatusNonAuthoritativeInfo: "Non-Authoritative Information",
+	StatusNoContent:            "No Content",
+	StatusResetContent:         "Reset Content",
+	StatusPartialContent:       "Partial Content",
+
+	StatusMultipleChoices:   "Multiple Choices",
+	StatusMovedPermanently:  "Moved Permanently",
+	StatusFound:             "Found",
+	StatusSeeOther:          "See Other",
+	StatusNotModified:       "Not Modified",
+	StatusUseProxy:          "Use Proxy",
+	StatusTemporaryRedirect: "Temporary Redirect",
+
+	StatusBadRequest:                   "Bad Request",
+	StatusUnauthorized:                 "Unauthorized",
+	StatusPaymentRequired:              "Payment Required",
+	StatusForbidden:                    "Forbidden",
+	StatusNotFound:                     "Not Found",
+	StatusMethodNotAllowed:             "Method Not Allowed",
+	StatusNotAcceptable:                "Not Acceptable",
+	StatusProxyAuthRequired:            "Proxy Authentication Required",
+	StatusRequestTimeout:               "Request Timeout",
+	StatusConflict:                     "Conflict",
+	StatusGone:                         "Gone",
+	StatusLengthRequired:               "Length Required",
+	StatusPreconditionFailed:           "Precondition Failed",
+	StatusRequestEntityTooLarge:        "Request Entity Too Large",
+	StatusRequestURITooLong:            "Request URI Too Long",
+	StatusUnsupportedMediaType:         "Unsupported Media Type",
+	StatusRequestedRangeNotSatisfiable: "Requested Range Not Satisfiable",
+	StatusExpectationFailed:            "Expectation Failed",
+	StatusTeapot:                       "I'm a teapot",
+
+	StatusInternalServerError:     "Internal Server Error",
+	StatusNotImplemented:          "Not Implemented",
+	StatusBadGateway:              "Bad Gateway",
+	StatusServiceUnavailable:      "Service Unavailable",
+	StatusGatewayTimeout:          "Gateway Timeout",
+	StatusHTTPVersionNotSupported: "HTTP Version Not Supported",
+
+	statusPreconditionRequired:          "Precondition Required",
+	statusTooManyRequests:               "Too Many Requests",
+	statusRequestHeaderFieldsTooLarge:   "Request Header Fields Too Large",
+	statusNetworkAuthenticationRequired: "Network Authentication Required",
+}
+
+// StatusText returns a text for the HTTP status code. It returns the empty
+// string if the code is unknown.
+func StatusText(code int) string {
+	return statusText[code]
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/http/transfer.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/transfer.go
new file mode 100644
index 000000000..7f6368652
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/transfer.go
@@ -0,0 +1,730 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package http
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/textproto"
+	"sort"
+	"strconv"
+	"strings"
+	"sync"
+)
+
+type errorReader struct {
+	err error
+}
+
+func (r *errorReader) Read(p []byte) (n int, err error) {
+	return 0, r.err
+}
+
+// transferWriter inspects the fields of a user-supplied Request or Response,
+// sanitizes them without changing the user object and provides methods for
+// writing the respective header, body and trailer in wire format.
+type transferWriter struct {
+	Method           string
+	Body             io.Reader
+	BodyCloser       io.Closer
+	ResponseToHEAD   bool
+	ContentLength    int64 // -1 means unknown, 0 means exactly none
+	Close            bool
+	TransferEncoding []string
+	Trailer          Header
+}
+
+func newTransferWriter(r interface{}) (t *transferWriter, err error) {
+	t = &transferWriter{}
+
+	// Extract relevant fields
+	atLeastHTTP11 := false
+	switch rr := r.(type) {
+	case *Request:
+		if rr.ContentLength != 0 && rr.Body == nil {
+			return nil, fmt.Errorf("http: Request.ContentLength=%d with nil Body", rr.ContentLength)
+		}
+		t.Method = rr.Method
+		t.Body = rr.Body
+		t.BodyCloser = rr.Body
+		t.ContentLength = rr.ContentLength
+		t.Close = rr.Close
+		t.TransferEncoding = rr.TransferEncoding
+		t.Trailer = rr.Trailer
+		atLeastHTTP11 = rr.ProtoAtLeast(1, 1)
+		if t.Body != nil && len(t.TransferEncoding) == 0 && atLeastHTTP11 {
+			if t.ContentLength == 0 {
+				// Test to see if it's actually zero or just unset.
+				var buf [1]byte
+				n, rerr := io.ReadFull(t.Body, buf[:])
+				if rerr != nil && rerr != io.EOF {
+					t.ContentLength = -1
+					t.Body = &errorReader{rerr}
+				} else if n == 1 {
+					// Oh, guess there is data in this Body Reader after all.
+					// The ContentLength field just wasn't set.
+					// Stich the Body back together again, re-attaching our
+					// consumed byte.
+					t.ContentLength = -1
+					t.Body = io.MultiReader(bytes.NewReader(buf[:]), t.Body)
+				} else {
+					// Body is actually empty.
+					t.Body = nil
+					t.BodyCloser = nil
+				}
+			}
+			if t.ContentLength < 0 {
+				t.TransferEncoding = []string{"chunked"}
+			}
+		}
+	case *Response:
+		if rr.Request != nil {
+			t.Method = rr.Request.Method
+		}
+		t.Body = rr.Body
+		t.BodyCloser = rr.Body
+		t.ContentLength = rr.ContentLength
+		t.Close = rr.Close
+		t.TransferEncoding = rr.TransferEncoding
+		t.Trailer = rr.Trailer
+		atLeastHTTP11 = rr.ProtoAtLeast(1, 1)
+		t.ResponseToHEAD = noBodyExpected(t.Method)
+	}
+
+	// Sanitize Body,ContentLength,TransferEncoding
+	if t.ResponseToHEAD {
+		t.Body = nil
+		if chunked(t.TransferEncoding) {
+			t.ContentLength = -1
+		}
+	} else {
+		if !atLeastHTTP11 || t.Body == nil {
+			t.TransferEncoding = nil
+		}
+		if chunked(t.TransferEncoding) {
+			t.ContentLength = -1
+		} else if t.Body == nil { // no chunking, no body
+			t.ContentLength = 0
+		}
+	}
+
+	// Sanitize Trailer
+	if !chunked(t.TransferEncoding) {
+		t.Trailer = nil
+	}
+
+	return t, nil
+}
+
+func noBodyExpected(requestMethod string) bool {
+	return requestMethod == "HEAD"
+}
+
+func (t *transferWriter) shouldSendContentLength() bool {
+	if chunked(t.TransferEncoding) {
+		return false
+	}
+	if t.ContentLength > 0 {
+		return true
+	}
+	// Many servers expect a Content-Length for these methods
+	if t.Method == "POST" || t.Method == "PUT" {
+		return true
+	}
+	if t.ContentLength == 0 && isIdentity(t.TransferEncoding) {
+		return true
+	}
+
+	return false
+}
+
+func (t *transferWriter) WriteHeader(w io.Writer) error {
+	if t.Close {
+		if _, err := io.WriteString(w, "Connection: close\r\n"); err != nil {
+			return err
+		}
+	}
+
+	// Write Content-Length and/or Transfer-Encoding whose values are a
+	// function of the sanitized field triple (Body, ContentLength,
+	// TransferEncoding)
+	if t.shouldSendContentLength() {
+		if _, err := io.WriteString(w, "Content-Length: "); err != nil {
+			return err
+		}
+		if _, err := io.WriteString(w, strconv.FormatInt(t.ContentLength, 10)+"\r\n"); err != nil {
+			return err
+		}
+	} else if chunked(t.TransferEncoding) {
+		if _, err := io.WriteString(w, "Transfer-Encoding: chunked\r\n"); err != nil {
+			return err
+		}
+	}
+
+	// Write Trailer header
+	if t.Trailer != nil {
+		keys := make([]string, 0, len(t.Trailer))
+		for k := range t.Trailer {
+			k = CanonicalHeaderKey(k)
+			switch k {
+			case "Transfer-Encoding", "Trailer", "Content-Length":
+				return &badStringError{"invalid Trailer key", k}
+			}
+			keys = append(keys, k)
+		}
+		if len(keys) > 0 {
+			sort.Strings(keys)
+			// TODO: could do better allocation-wise here, but trailers are rare,
+			// so being lazy for now.
+			if _, err := io.WriteString(w, "Trailer: "+strings.Join(keys, ",")+"\r\n"); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+func (t *transferWriter) WriteBody(w io.Writer) error {
+	var err error
+	var ncopy int64
+
+	// Write body
+	if t.Body != nil {
+		if chunked(t.TransferEncoding) {
+			cw := newChunkedWriter(w)
+			_, err = io.Copy(cw, t.Body)
+			if err == nil {
+				err = cw.Close()
+			}
+		} else if t.ContentLength == -1 {
+			ncopy, err = io.Copy(w, t.Body)
+		} else {
+			ncopy, err = io.Copy(w, io.LimitReader(t.Body, t.ContentLength))
+			if err != nil {
+				return err
+			}
+			var nextra int64
+			nextra, err = io.Copy(ioutil.Discard, t.Body)
+			ncopy += nextra
+		}
+		if err != nil {
+			return err
+		}
+		if err = t.BodyCloser.Close(); err != nil {
+			return err
+		}
+	}
+
+	if !t.ResponseToHEAD && t.ContentLength != -1 && t.ContentLength != ncopy {
+		return fmt.Errorf("http: Request.ContentLength=%d with Body length %d",
+			t.ContentLength, ncopy)
+	}
+
+	// TODO(petar): Place trailer writer code here.
+	if chunked(t.TransferEncoding) {
+		// Write Trailer header
+		if t.Trailer != nil {
+			if err := t.Trailer.Write(w); err != nil {
+				return err
+			}
+		}
+		// Last chunk, empty trailer
+		_, err = io.WriteString(w, "\r\n")
+	}
+	return err
+}
+
+type transferReader struct {
+	// Input
+	Header        Header
+	StatusCode    int
+	RequestMethod string
+	ProtoMajor    int
+	ProtoMinor    int
+	// Output
+	Body             io.ReadCloser
+	ContentLength    int64
+	TransferEncoding []string
+	Close            bool
+	Trailer          Header
+}
+
+// bodyAllowedForStatus reports whether a given response status code
+// permits a body.  See RFC2616, section 4.4.
+func bodyAllowedForStatus(status int) bool {
+	switch {
+	case status >= 100 && status <= 199:
+		return false
+	case status == 204:
+		return false
+	case status == 304:
+		return false
+	}
+	return true
+}
+
+var (
+	suppressedHeaders304    = []string{"Content-Type", "Content-Length", "Transfer-Encoding"}
+	suppressedHeadersNoBody = []string{"Content-Length", "Transfer-Encoding"}
+)
+
+func suppressedHeaders(status int) []string {
+	switch {
+	case status == 304:
+		// RFC 2616 section 10.3.5: "the response MUST NOT include other entity-headers"
+		return suppressedHeaders304
+	case !bodyAllowedForStatus(status):
+		return suppressedHeadersNoBody
+	}
+	return nil
+}
+
+// msg is *Request or *Response.
+func readTransfer(msg interface{}, r *bufio.Reader) (err error) {
+	t := &transferReader{RequestMethod: "GET"}
+
+	// Unify input
+	isResponse := false
+	switch rr := msg.(type) {
+	case *Response:
+		t.Header = rr.Header
+		t.StatusCode = rr.StatusCode
+		t.ProtoMajor = rr.ProtoMajor
+		t.ProtoMinor = rr.ProtoMinor
+		t.Close = shouldClose(t.ProtoMajor, t.ProtoMinor, t.Header)
+		isResponse = true
+		if rr.Request != nil {
+			t.RequestMethod = rr.Request.Method
+		}
+	case *Request:
+		t.Header = rr.Header
+		t.ProtoMajor = rr.ProtoMajor
+		t.ProtoMinor = rr.ProtoMinor
+		// Transfer semantics for Requests are exactly like those for
+		// Responses with status code 200, responding to a GET method
+		t.StatusCode = 200
+	default:
+		panic("unexpected type")
+	}
+
+	// Default to HTTP/1.1
+	if t.ProtoMajor == 0 && t.ProtoMinor == 0 {
+		t.ProtoMajor, t.ProtoMinor = 1, 1
+	}
+
+	// Transfer encoding, content length
+	t.TransferEncoding, err = fixTransferEncoding(t.RequestMethod, t.Header)
+	if err != nil {
+		return err
+	}
+
+	realLength, err := fixLength(isResponse, t.StatusCode, t.RequestMethod, t.Header, t.TransferEncoding)
+	if err != nil {
+		return err
+	}
+	if isResponse && t.RequestMethod == "HEAD" {
+		if n, err := parseContentLength(t.Header.get("Content-Length")); err != nil {
+			return err
+		} else {
+			t.ContentLength = n
+		}
+	} else {
+		t.ContentLength = realLength
+	}
+
+	// Trailer
+	t.Trailer, err = fixTrailer(t.Header, t.TransferEncoding)
+	if err != nil {
+		return err
+	}
+
+	// If there is no Content-Length or chunked Transfer-Encoding on a *Response
+	// and the status is not 1xx, 204 or 304, then the body is unbounded.
+	// See RFC2616, section 4.4.
+	switch msg.(type) {
+	case *Response:
+		if realLength == -1 &&
+			!chunked(t.TransferEncoding) &&
+			bodyAllowedForStatus(t.StatusCode) {
+			// Unbounded body.
+			t.Close = true
+		}
+	}
+
+	// Prepare body reader.  ContentLength < 0 means chunked encoding
+	// or close connection when finished, since multipart is not supported yet
+	switch {
+	case chunked(t.TransferEncoding):
+		if noBodyExpected(t.RequestMethod) {
+			t.Body = eofReader
+		} else {
+			t.Body = &body{src: newChunkedReader(r), hdr: msg, r: r, closing: t.Close}
+		}
+	case realLength == 0:
+		t.Body = eofReader
+	case realLength > 0:
+		t.Body = &body{src: io.LimitReader(r, realLength), closing: t.Close}
+	default:
+		// realLength < 0, i.e. "Content-Length" not mentioned in header
+		if t.Close {
+			// Close semantics (i.e. HTTP/1.0)
+			t.Body = &body{src: r, closing: t.Close}
+		} else {
+			// Persistent connection (i.e. HTTP/1.1)
+			t.Body = eofReader
+		}
+	}
+
+	// Unify output
+	switch rr := msg.(type) {
+	case *Request:
+		rr.Body = t.Body
+		rr.ContentLength = t.ContentLength
+		rr.TransferEncoding = t.TransferEncoding
+		rr.Close = t.Close
+		rr.Trailer = t.Trailer
+	case *Response:
+		rr.Body = t.Body
+		rr.ContentLength = t.ContentLength
+		rr.TransferEncoding = t.TransferEncoding
+		rr.Close = t.Close
+		rr.Trailer = t.Trailer
+	}
+
+	return nil
+}
+
+// Checks whether chunked is part of the encodings stack
+func chunked(te []string) bool { return len(te) > 0 && te[0] == "chunked" }
+
+// Checks whether the encoding is explicitly "identity".
+func isIdentity(te []string) bool { return len(te) == 1 && te[0] == "identity" }
+
+// Sanitize transfer encoding
+func fixTransferEncoding(requestMethod string, header Header) ([]string, error) {
+	raw, present := header["Transfer-Encoding"]
+	if !present {
+		return nil, nil
+	}
+
+	delete(header, "Transfer-Encoding")
+
+	encodings := strings.Split(raw[0], ",")
+	te := make([]string, 0, len(encodings))
+	// TODO: Even though we only support "identity" and "chunked"
+	// encodings, the loop below is designed with foresight. One
+	// invariant that must be maintained is that, if present,
+	// chunked encoding must always come first.
+	for _, encoding := range encodings {
+		encoding = strings.ToLower(strings.TrimSpace(encoding))
+		// "identity" encoding is not recorded
+		if encoding == "identity" {
+			break
+		}
+		if encoding != "chunked" {
+			return nil, &badStringError{"unsupported transfer encoding", encoding}
+		}
+		te = te[0 : len(te)+1]
+		te[len(te)-1] = encoding
+	}
+	if len(te) > 1 {
+		return nil, &badStringError{"too many transfer encodings", strings.Join(te, ",")}
+	}
+	if len(te) > 0 {
+		// Chunked encoding trumps Content-Length. See RFC 2616
+		// Section 4.4. Currently len(te) > 0 implies chunked
+		// encoding.
+		delete(header, "Content-Length")
+		return te, nil
+	}
+
+	return nil, nil
+}
+
+// Determine the expected body length, using RFC 2616 Section 4.4. This
+// function is not a method, because ultimately it should be shared by
+// ReadResponse and ReadRequest.
+func fixLength(isResponse bool, status int, requestMethod string, header Header, te []string) (int64, error) {
+
+	// Logic based on response type or status
+	if noBodyExpected(requestMethod) {
+		return 0, nil
+	}
+	if status/100 == 1 {
+		return 0, nil
+	}
+	switch status {
+	case 204, 304:
+		return 0, nil
+	}
+
+	// Logic based on Transfer-Encoding
+	if chunked(te) {
+		return -1, nil
+	}
+
+	// Logic based on Content-Length
+	cl := strings.TrimSpace(header.get("Content-Length"))
+	if cl != "" {
+		n, err := parseContentLength(cl)
+		if err != nil {
+			return -1, err
+		}
+		return n, nil
+	} else {
+		header.Del("Content-Length")
+	}
+
+	if !isResponse && requestMethod == "GET" {
+		// RFC 2616 doesn't explicitly permit nor forbid an
+		// entity-body on a GET request so we permit one if
+		// declared, but we default to 0 here (not -1 below)
+		// if there's no mention of a body.
+		return 0, nil
+	}
+
+	// Body-EOF logic based on other methods (like closing, or chunked coding)
+	return -1, nil
+}
+
+// Determine whether to hang up after sending a request and body, or
+// receiving a response and body
+// 'header' is the request headers
+func shouldClose(major, minor int, header Header) bool {
+	if major < 1 {
+		return true
+	} else if major == 1 && minor == 0 {
+		if !strings.Contains(strings.ToLower(header.get("Connection")), "keep-alive") {
+			return true
+		}
+		return false
+	} else {
+		// TODO: Should split on commas, toss surrounding white space,
+		// and check each field.
+		if strings.ToLower(header.get("Connection")) == "close" {
+			header.Del("Connection")
+			return true
+		}
+	}
+	return false
+}
+
+// Parse the trailer header
+func fixTrailer(header Header, te []string) (Header, error) {
+	raw := header.get("Trailer")
+	if raw == "" {
+		return nil, nil
+	}
+
+	header.Del("Trailer")
+	trailer := make(Header)
+	keys := strings.Split(raw, ",")
+	for _, key := range keys {
+		key = CanonicalHeaderKey(strings.TrimSpace(key))
+		switch key {
+		case "Transfer-Encoding", "Trailer", "Content-Length":
+			return nil, &badStringError{"bad trailer key", key}
+		}
+		trailer[key] = nil
+	}
+	if len(trailer) == 0 {
+		return nil, nil
+	}
+	if !chunked(te) {
+		// Trailer and no chunking
+		return nil, ErrUnexpectedTrailer
+	}
+	return trailer, nil
+}
+
+// body turns a Reader into a ReadCloser.
+// Close ensures that the body has been fully read
+// and then reads the trailer if necessary.
+type body struct {
+	src     io.Reader
+	hdr     interface{}   // non-nil (Response or Request) value means read trailer
+	r       *bufio.Reader // underlying wire-format reader for the trailer
+	closing bool          // is the connection to be closed after reading body?
+
+	mu     sync.Mutex // guards closed, and calls to Read and Close
+	closed bool
+}
+
+// ErrBodyReadAfterClose is returned when reading a Request or Response
+// Body after the body has been closed. This typically happens when the body is
+// read after an HTTP Handler calls WriteHeader or Write on its
+// ResponseWriter.
+var ErrBodyReadAfterClose = errors.New("http: invalid Read on closed Body")
+
+func (b *body) Read(p []byte) (n int, err error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	if b.closed {
+		return 0, ErrBodyReadAfterClose
+	}
+	return b.readLocked(p)
+}
+
+// Must hold b.mu.
+func (b *body) readLocked(p []byte) (n int, err error) {
+	n, err = b.src.Read(p)
+
+	if err == io.EOF {
+		// Chunked case. Read the trailer.
+		if b.hdr != nil {
+			if e := b.readTrailer(); e != nil {
+				err = e
+			}
+			b.hdr = nil
+		} else {
+			// If the server declared the Content-Length, our body is a LimitedReader
+			// and we need to check whether this EOF arrived early.
+			if lr, ok := b.src.(*io.LimitedReader); ok && lr.N > 0 {
+				err = io.ErrUnexpectedEOF
+			}
+		}
+	}
+
+	// If we can return an EOF here along with the read data, do
+	// so. This is optional per the io.Reader contract, but doing
+	// so helps the HTTP transport code recycle its connection
+	// earlier (since it will see this EOF itself), even if the
+	// client doesn't do future reads or Close.
+	if err == nil && n > 0 {
+		if lr, ok := b.src.(*io.LimitedReader); ok && lr.N == 0 {
+			err = io.EOF
+		}
+	}
+
+	return n, err
+}
+
+var (
+	singleCRLF = []byte("\r\n")
+	doubleCRLF = []byte("\r\n\r\n")
+)
+
+func seeUpcomingDoubleCRLF(r *bufio.Reader) bool {
+	for peekSize := 4; ; peekSize++ {
+		// This loop stops when Peek returns an error,
+		// which it does when r's buffer has been filled.
+		buf, err := r.Peek(peekSize)
+		if bytes.HasSuffix(buf, doubleCRLF) {
+			return true
+		}
+		if err != nil {
+			break
+		}
+	}
+	return false
+}
+
+var errTrailerEOF = errors.New("http: unexpected EOF reading trailer")
+
+func (b *body) readTrailer() error {
+	// The common case, since nobody uses trailers.
+	buf, err := b.r.Peek(2)
+	if bytes.Equal(buf, singleCRLF) {
+		b.r.ReadByte()
+		b.r.ReadByte()
+		return nil
+	}
+	if len(buf) < 2 {
+		return errTrailerEOF
+	}
+	if err != nil {
+		return err
+	}
+
+	// Make sure there's a header terminator coming up, to prevent
+	// a DoS with an unbounded size Trailer.  It's not easy to
+	// slip in a LimitReader here, as textproto.NewReader requires
+	// a concrete *bufio.Reader.  Also, we can't get all the way
+	// back up to our conn's LimitedReader that *might* be backing
+	// this bufio.Reader.  Instead, a hack: we iteratively Peek up
+	// to the bufio.Reader's max size, looking for a double CRLF.
+	// This limits the trailer to the underlying buffer size, typically 4kB.
+	if !seeUpcomingDoubleCRLF(b.r) {
+		return errors.New("http: suspiciously long trailer after chunked body")
+	}
+
+	hdr, err := textproto.NewReader(b.r).ReadMIMEHeader()
+	if err != nil {
+		if err == io.EOF {
+			return errTrailerEOF
+		}
+		return err
+	}
+	switch rr := b.hdr.(type) {
+	case *Request:
+		mergeSetHeader(&rr.Trailer, Header(hdr))
+	case *Response:
+		mergeSetHeader(&rr.Trailer, Header(hdr))
+	}
+	return nil
+}
+
+func mergeSetHeader(dst *Header, src Header) {
+	if *dst == nil {
+		*dst = src
+		return
+	}
+	for k, vv := range src {
+		(*dst)[k] = vv
+	}
+}
+
+func (b *body) Close() error {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	if b.closed {
+		return nil
+	}
+	var err error
+	switch {
+	case b.hdr == nil && b.closing:
+		// no trailer and closing the connection next.
+		// no point in reading to EOF.
+	default:
+		// Fully consume the body, which will also lead to us reading
+		// the trailer headers after the body, if present.
+		_, err = io.Copy(ioutil.Discard, bodyLocked{b})
+	}
+	b.closed = true
+	return err
+}
+
+// bodyLocked is a io.Reader reading from a *body when its mutex is
+// already held.
+type bodyLocked struct {
+	b *body
+}
+
+func (bl bodyLocked) Read(p []byte) (n int, err error) {
+	if bl.b.closed {
+		return 0, ErrBodyReadAfterClose
+	}
+	return bl.b.readLocked(p)
+}
+
+// parseContentLength trims whitespace from s and returns -1 if no value
+// is set, or the value if it's >= 0.
+func parseContentLength(cl string) (int64, error) {
+	cl = strings.TrimSpace(cl)
+	if cl == "" {
+		return -1, nil
+	}
+	n, err := strconv.ParseInt(cl, 10, 64)
+	if err != nil || n < 0 {
+		return 0, &badStringError{"bad Content-Length", cl}
+	}
+	return n, nil
+
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/http/transport.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/transport.go
new file mode 100644
index 000000000..c58e2dc35
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/transport.go
@@ -0,0 +1,1208 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// HTTP client implementation. See RFC 2616.
+//
+// This is the low-level Transport implementation of RoundTripper.
+// The high-level interface is in client.go.
+
+package http
+
+import (
+	"bufio"
+	"compress/gzip"
+	"errors"
+	"fmt"
+	"github.com/masterzen/azure-sdk-for-go/core/tls"
+	"io"
+	"log"
+	"net"
+	"net/url"
+	"os"
+	"strings"
+	"sync"
+	"time"
+)
+
+// DefaultTransport is the default implementation of Transport and is
+// used by DefaultClient. It establishes network connections as needed
+// and caches them for reuse by subsequent calls. It uses HTTP proxies
+// as directed by the $HTTP_PROXY and $NO_PROXY (or $http_proxy and
+// $no_proxy) environment variables.
+var DefaultTransport RoundTripper = &Transport{
+	Proxy: ProxyFromEnvironment,
+	Dial: (&net.Dialer{
+		Timeout:   30 * time.Second,
+		KeepAlive: 30 * time.Second,
+	}).Dial,
+	TLSHandshakeTimeout: 10 * time.Second,
+}
+
+// DefaultMaxIdleConnsPerHost is the default value of Transport's
+// MaxIdleConnsPerHost.
+const DefaultMaxIdleConnsPerHost = 2
+
+// Transport is an implementation of RoundTripper that supports http,
+// https, and http proxies (for either http or https with CONNECT).
+// Transport can also cache connections for future re-use.
+type Transport struct {
+	idleMu      sync.Mutex
+	idleConn    map[connectMethodKey][]*persistConn
+	idleConnCh  map[connectMethodKey]chan *persistConn
+	reqMu       sync.Mutex
+	reqCanceler map[*Request]func()
+	altMu       sync.RWMutex
+	altProto    map[string]RoundTripper // nil or map of URI scheme => RoundTripper
+
+	// Proxy specifies a function to return a proxy for a given
+	// Request. If the function returns a non-nil error, the
+	// request is aborted with the provided error.
+	// If Proxy is nil or returns a nil *URL, no proxy is used.
+	Proxy func(*Request) (*url.URL, error)
+
+	// Dial specifies the dial function for creating TCP
+	// connections.
+	// If Dial is nil, net.Dial is used.
+	Dial func(network, addr string) (net.Conn, error)
+
+	// TLSClientConfig specifies the TLS configuration to use with
+	// tls.Client. If nil, the default configuration is used.
+	TLSClientConfig *tls.Config
+
+	// TLSHandshakeTimeout specifies the maximum amount of time waiting to
+	// wait for a TLS handshake. Zero means no timeout.
+	TLSHandshakeTimeout time.Duration
+
+	// DisableKeepAlives, if true, prevents re-use of TCP connections
+	// between different HTTP requests.
+	DisableKeepAlives bool
+
+	// DisableCompression, if true, prevents the Transport from
+	// requesting compression with an "Accept-Encoding: gzip"
+	// request header when the Request contains no existing
+	// Accept-Encoding value. If the Transport requests gzip on
+	// its own and gets a gzipped response, it's transparently
+	// decoded in the Response.Body. However, if the user
+	// explicitly requested gzip it is not automatically
+	// uncompressed.
+	DisableCompression bool
+
+	// MaxIdleConnsPerHost, if non-zero, controls the maximum idle
+	// (keep-alive) to keep per-host.  If zero,
+	// DefaultMaxIdleConnsPerHost is used.
+	MaxIdleConnsPerHost int
+
+	// ResponseHeaderTimeout, if non-zero, specifies the amount of
+	// time to wait for a server's response headers after fully
+	// writing the request (including its body, if any). This
+	// time does not include the time to read the response body.
+	ResponseHeaderTimeout time.Duration
+
+	// TODO: tunable on global max cached connections
+	// TODO: tunable on timeout on cached connections
+}
+
+// ProxyFromEnvironment returns the URL of the proxy to use for a
+// given request, as indicated by the environment variables
+// $HTTP_PROXY and $NO_PROXY (or $http_proxy and $no_proxy).
+// An error is returned if the proxy environment is invalid.
+// A nil URL and nil error are returned if no proxy is defined in the
+// environment, or a proxy should not be used for the given request.
+//
+// As a special case, if req.URL.Host is "localhost" (with or without
+// a port number), then a nil URL and nil error will be returned.
+func ProxyFromEnvironment(req *Request) (*url.URL, error) {
+	proxy := httpProxyEnv.Get()
+	if proxy == "" {
+		return nil, nil
+	}
+	if !useProxy(canonicalAddr(req.URL)) {
+		return nil, nil
+	}
+	proxyURL, err := url.Parse(proxy)
+	if err != nil || !strings.HasPrefix(proxyURL.Scheme, "http") {
+		// proxy was bogus. Try prepending "http://" to it and
+		// see if that parses correctly. If not, we fall
+		// through and complain about the original one.
+		if proxyURL, err := url.Parse("http://" + proxy); err == nil {
+			return proxyURL, nil
+		}
+	}
+	if err != nil {
+		return nil, fmt.Errorf("invalid proxy address %q: %v", proxy, err)
+	}
+	return proxyURL, nil
+}
+
+// ProxyURL returns a proxy function (for use in a Transport)
+// that always returns the same URL.
+func ProxyURL(fixedURL *url.URL) func(*Request) (*url.URL, error) {
+	return func(*Request) (*url.URL, error) {
+		return fixedURL, nil
+	}
+}
+
+// transportRequest is a wrapper around a *Request that adds
+// optional extra headers to write.
+type transportRequest struct {
+	*Request        // original request, not to be mutated
+	extra    Header // extra headers to write, or nil
+}
+
+func (tr *transportRequest) extraHeaders() Header {
+	if tr.extra == nil {
+		tr.extra = make(Header)
+	}
+	return tr.extra
+}
+
+// RoundTrip implements the RoundTripper interface.
+//
+// For higher-level HTTP client support (such as handling of cookies
+// and redirects), see Get, Post, and the Client type.
+func (t *Transport) RoundTrip(req *Request) (resp *Response, err error) {
+	if req.URL == nil {
+		req.closeBody()
+		return nil, errors.New("http: nil Request.URL")
+	}
+	if req.Header == nil {
+		req.closeBody()
+		return nil, errors.New("http: nil Request.Header")
+	}
+	if req.URL.Scheme != "http" && req.URL.Scheme != "https" {
+		t.altMu.RLock()
+		var rt RoundTripper
+		if t.altProto != nil {
+			rt = t.altProto[req.URL.Scheme]
+		}
+		t.altMu.RUnlock()
+		if rt == nil {
+			req.closeBody()
+			return nil, &badStringError{"unsupported protocol scheme", req.URL.Scheme}
+		}
+		return rt.RoundTrip(req)
+	}
+	if req.URL.Host == "" {
+		req.closeBody()
+		return nil, errors.New("http: no Host in request URL")
+	}
+	treq := &transportRequest{Request: req}
+	cm, err := t.connectMethodForRequest(treq)
+	if err != nil {
+		req.closeBody()
+		return nil, err
+	}
+
+	// Get the cached or newly-created connection to either the
+	// host (for http or https), the http proxy, or the http proxy
+	// pre-CONNECTed to https server.  In any case, we'll be ready
+	// to send it requests.
+	pconn, err := t.getConn(req, cm)
+	if err != nil {
+		t.setReqCanceler(req, nil)
+		req.closeBody()
+		return nil, err
+	}
+
+	return pconn.roundTrip(treq)
+}
+
+// RegisterProtocol registers a new protocol with scheme.
+// The Transport will pass requests using the given scheme to rt.
+// It is rt's responsibility to simulate HTTP request semantics.
+//
+// RegisterProtocol can be used by other packages to provide
+// implementations of protocol schemes like "ftp" or "file".
+func (t *Transport) RegisterProtocol(scheme string, rt RoundTripper) {
+	if scheme == "http" || scheme == "https" {
+		panic("protocol " + scheme + " already registered")
+	}
+	t.altMu.Lock()
+	defer t.altMu.Unlock()
+	if t.altProto == nil {
+		t.altProto = make(map[string]RoundTripper)
+	}
+	if _, exists := t.altProto[scheme]; exists {
+		panic("protocol " + scheme + " already registered")
+	}
+	t.altProto[scheme] = rt
+}
+
+// CloseIdleConnections closes any connections which were previously
+// connected from previous requests but are now sitting idle in
+// a "keep-alive" state. It does not interrupt any connections currently
+// in use.
+func (t *Transport) CloseIdleConnections() {
+	t.idleMu.Lock()
+	m := t.idleConn
+	t.idleConn = nil
+	t.idleConnCh = nil
+	t.idleMu.Unlock()
+	for _, conns := range m {
+		for _, pconn := range conns {
+			pconn.close()
+		}
+	}
+}
+
+// CancelRequest cancels an in-flight request by closing its
+// connection.
+func (t *Transport) CancelRequest(req *Request) {
+	t.reqMu.Lock()
+	cancel := t.reqCanceler[req]
+	t.reqMu.Unlock()
+	if cancel != nil {
+		cancel()
+	}
+}
+
+//
+// Private implementation past this point.
+//
+
+var (
+	httpProxyEnv = &envOnce{
+		names: []string{"HTTP_PROXY", "http_proxy"},
+	}
+	noProxyEnv = &envOnce{
+		names: []string{"NO_PROXY", "no_proxy"},
+	}
+)
+
+// envOnce looks up an environment variable (optionally by multiple
+// names) once. It mitigates expensive lookups on some platforms
+// (e.g. Windows).
+type envOnce struct {
+	names []string
+	once  sync.Once
+	val   string
+}
+
+func (e *envOnce) Get() string {
+	e.once.Do(e.init)
+	return e.val
+}
+
+func (e *envOnce) init() {
+	for _, n := range e.names {
+		e.val = os.Getenv(n)
+		if e.val != "" {
+			return
+		}
+	}
+}
+
+// reset is used by tests
+func (e *envOnce) reset() {
+	e.once = sync.Once{}
+	e.val = ""
+}
+
+func (t *Transport) connectMethodForRequest(treq *transportRequest) (cm connectMethod, err error) {
+	cm.targetScheme = treq.URL.Scheme
+	cm.targetAddr = canonicalAddr(treq.URL)
+	if t.Proxy != nil {
+		cm.proxyURL, err = t.Proxy(treq.Request)
+	}
+	return cm, nil
+}
+
+// proxyAuth returns the Proxy-Authorization header to set
+// on requests, if applicable.
+func (cm *connectMethod) proxyAuth() string {
+	if cm.proxyURL == nil {
+		return ""
+	}
+	if u := cm.proxyURL.User; u != nil {
+		username := u.Username()
+		password, _ := u.Password()
+		return "Basic " + basicAuth(username, password)
+	}
+	return ""
+}
+
+// putIdleConn adds pconn to the list of idle persistent connections awaiting
+// a new request.
+// If pconn is no longer needed or not in a good state, putIdleConn
+// returns false.
+func (t *Transport) putIdleConn(pconn *persistConn) bool {
+	if t.DisableKeepAlives || t.MaxIdleConnsPerHost < 0 {
+		pconn.close()
+		return false
+	}
+	if pconn.isBroken() {
+		return false
+	}
+	key := pconn.cacheKey
+	max := t.MaxIdleConnsPerHost
+	if max == 0 {
+		max = DefaultMaxIdleConnsPerHost
+	}
+	t.idleMu.Lock()
+
+	waitingDialer := t.idleConnCh[key]
+	select {
+	case waitingDialer <- pconn:
+		// We're done with this pconn and somebody else is
+		// currently waiting for a conn of this type (they're
+		// actively dialing, but this conn is ready
+		// first). Chrome calls this socket late binding.  See
+		// https://insouciant.org/tech/connection-management-in-chromium/
+		t.idleMu.Unlock()
+		return true
+	default:
+		if waitingDialer != nil {
+			// They had populated this, but their dial won
+			// first, so we can clean up this map entry.
+			delete(t.idleConnCh, key)
+		}
+	}
+	if t.idleConn == nil {
+		t.idleConn = make(map[connectMethodKey][]*persistConn)
+	}
+	if len(t.idleConn[key]) >= max {
+		t.idleMu.Unlock()
+		pconn.close()
+		return false
+	}
+	for _, exist := range t.idleConn[key] {
+		if exist == pconn {
+			log.Fatalf("dup idle pconn %p in freelist", pconn)
+		}
+	}
+	t.idleConn[key] = append(t.idleConn[key], pconn)
+	t.idleMu.Unlock()
+	return true
+}
+
+// getIdleConnCh returns a channel to receive and return idle
+// persistent connection for the given connectMethod.
+// It may return nil, if persistent connections are not being used.
+func (t *Transport) getIdleConnCh(cm connectMethod) chan *persistConn {
+	if t.DisableKeepAlives {
+		return nil
+	}
+	key := cm.key()
+	t.idleMu.Lock()
+	defer t.idleMu.Unlock()
+	if t.idleConnCh == nil {
+		t.idleConnCh = make(map[connectMethodKey]chan *persistConn)
+	}
+	ch, ok := t.idleConnCh[key]
+	if !ok {
+		ch = make(chan *persistConn)
+		t.idleConnCh[key] = ch
+	}
+	return ch
+}
+
+func (t *Transport) getIdleConn(cm connectMethod) (pconn *persistConn) {
+	key := cm.key()
+	t.idleMu.Lock()
+	defer t.idleMu.Unlock()
+	if t.idleConn == nil {
+		return nil
+	}
+	for {
+		pconns, ok := t.idleConn[key]
+		if !ok {
+			return nil
+		}
+		if len(pconns) == 1 {
+			pconn = pconns[0]
+			delete(t.idleConn, key)
+		} else {
+			// 2 or more cached connections; pop last
+			// TODO: queue?
+			pconn = pconns[len(pconns)-1]
+			t.idleConn[key] = pconns[:len(pconns)-1]
+		}
+		if !pconn.isBroken() {
+			return
+		}
+	}
+}
+
+func (t *Transport) setReqCanceler(r *Request, fn func()) {
+	t.reqMu.Lock()
+	defer t.reqMu.Unlock()
+	if t.reqCanceler == nil {
+		t.reqCanceler = make(map[*Request]func())
+	}
+	if fn != nil {
+		t.reqCanceler[r] = fn
+	} else {
+		delete(t.reqCanceler, r)
+	}
+}
+
+func (t *Transport) dial(network, addr string) (c net.Conn, err error) {
+	if t.Dial != nil {
+		return t.Dial(network, addr)
+	}
+	return net.Dial(network, addr)
+}
+
+// getConn dials and creates a new persistConn to the target as
+// specified in the connectMethod.  This includes doing a proxy CONNECT
+// and/or setting up TLS.  If this doesn't return an error, the persistConn
+// is ready to write requests to.
+func (t *Transport) getConn(req *Request, cm connectMethod) (*persistConn, error) {
+	if pc := t.getIdleConn(cm); pc != nil {
+		return pc, nil
+	}
+
+	type dialRes struct {
+		pc  *persistConn
+		err error
+	}
+	dialc := make(chan dialRes)
+
+	handlePendingDial := func() {
+		if v := <-dialc; v.err == nil {
+			t.putIdleConn(v.pc)
+		}
+	}
+
+	cancelc := make(chan struct{})
+	t.setReqCanceler(req, func() { close(cancelc) })
+
+	go func() {
+		pc, err := t.dialConn(cm)
+		dialc <- dialRes{pc, err}
+	}()
+
+	idleConnCh := t.getIdleConnCh(cm)
+	select {
+	case v := <-dialc:
+		// Our dial finished.
+		return v.pc, v.err
+	case pc := <-idleConnCh:
+		// Another request finished first and its net.Conn
+		// became available before our dial. Or somebody
+		// else's dial that they didn't use.
+		// But our dial is still going, so give it away
+		// when it finishes:
+		go handlePendingDial()
+		return pc, nil
+	case <-cancelc:
+		go handlePendingDial()
+		return nil, errors.New("net/http: request canceled while waiting for connection")
+	}
+}
+
+func (t *Transport) dialConn(cm connectMethod) (*persistConn, error) {
+	conn, err := t.dial("tcp", cm.addr())
+	if err != nil {
+		if cm.proxyURL != nil {
+			err = fmt.Errorf("http: error connecting to proxy %s: %v", cm.proxyURL, err)
+		}
+		return nil, err
+	}
+
+	pa := cm.proxyAuth()
+
+	pconn := &persistConn{
+		t:          t,
+		cacheKey:   cm.key(),
+		conn:       conn,
+		reqch:      make(chan requestAndChan, 1),
+		writech:    make(chan writeRequest, 1),
+		closech:    make(chan struct{}),
+		writeErrCh: make(chan error, 1),
+	}
+
+	switch {
+	case cm.proxyURL == nil:
+		// Do nothing.
+	case cm.targetScheme == "http":
+		pconn.isProxy = true
+		if pa != "" {
+			pconn.mutateHeaderFunc = func(h Header) {
+				h.Set("Proxy-Authorization", pa)
+			}
+		}
+	case cm.targetScheme == "https":
+		connectReq := &Request{
+			Method: "CONNECT",
+			URL:    &url.URL{Opaque: cm.targetAddr},
+			Host:   cm.targetAddr,
+			Header: make(Header),
+		}
+		if pa != "" {
+			connectReq.Header.Set("Proxy-Authorization", pa)
+		}
+		connectReq.Write(conn)
+
+		// Read response.
+		// Okay to use and discard buffered reader here, because
+		// TLS server will not speak until spoken to.
+		br := bufio.NewReader(conn)
+		resp, err := ReadResponse(br, connectReq)
+		if err != nil {
+			conn.Close()
+			return nil, err
+		}
+		if resp.StatusCode != 200 {
+			f := strings.SplitN(resp.Status, " ", 2)
+			conn.Close()
+			return nil, errors.New(f[1])
+		}
+	}
+
+	if cm.targetScheme == "https" {
+		// Initiate TLS and check remote host name against certificate.
+		cfg := t.TLSClientConfig
+		if cfg == nil || cfg.ServerName == "" {
+			host := cm.tlsHost()
+			if cfg == nil {
+				cfg = &tls.Config{ServerName: host}
+			} else {
+				clone := *cfg // shallow clone
+				clone.ServerName = host
+				cfg = &clone
+			}
+		}
+		plainConn := conn
+		tlsConn := tls.Client(plainConn, cfg)
+		errc := make(chan error, 2)
+		var timer *time.Timer // for canceling TLS handshake
+		if d := t.TLSHandshakeTimeout; d != 0 {
+			timer = time.AfterFunc(d, func() {
+				errc <- tlsHandshakeTimeoutError{}
+			})
+		}
+		go func() {
+			err := tlsConn.Handshake()
+			if timer != nil {
+				timer.Stop()
+			}
+			errc <- err
+		}()
+		if err := <-errc; err != nil {
+			plainConn.Close()
+			return nil, err
+		}
+		if !cfg.InsecureSkipVerify {
+			if err := tlsConn.VerifyHostname(cfg.ServerName); err != nil {
+				plainConn.Close()
+				return nil, err
+			}
+		}
+		cs := tlsConn.ConnectionState()
+		pconn.tlsState = &cs
+		pconn.conn = tlsConn
+	}
+
+	pconn.br = bufio.NewReader(noteEOFReader{pconn.conn, &pconn.sawEOF})
+	pconn.bw = bufio.NewWriter(pconn.conn)
+	go pconn.readLoop()
+	go pconn.writeLoop()
+	return pconn, nil
+}
+
+// useProxy returns true if requests to addr should use a proxy,
+// according to the NO_PROXY or no_proxy environment variable.
+// addr is always a canonicalAddr with a host and port.
+func useProxy(addr string) bool {
+	if len(addr) == 0 {
+		return true
+	}
+	host, _, err := net.SplitHostPort(addr)
+	if err != nil {
+		return false
+	}
+	if host == "localhost" {
+		return false
+	}
+	if ip := net.ParseIP(host); ip != nil {
+		if ip.IsLoopback() {
+			return false
+		}
+	}
+
+	no_proxy := noProxyEnv.Get()
+	if no_proxy == "*" {
+		return false
+	}
+
+	addr = strings.ToLower(strings.TrimSpace(addr))
+	if hasPort(addr) {
+		addr = addr[:strings.LastIndex(addr, ":")]
+	}
+
+	for _, p := range strings.Split(no_proxy, ",") {
+		p = strings.ToLower(strings.TrimSpace(p))
+		if len(p) == 0 {
+			continue
+		}
+		if hasPort(p) {
+			p = p[:strings.LastIndex(p, ":")]
+		}
+		if addr == p {
+			return false
+		}
+		if p[0] == '.' && (strings.HasSuffix(addr, p) || addr == p[1:]) {
+			// no_proxy ".foo.com" matches "bar.foo.com" or "foo.com"
+			return false
+		}
+		if p[0] != '.' && strings.HasSuffix(addr, p) && addr[len(addr)-len(p)-1] == '.' {
+			// no_proxy "foo.com" matches "bar.foo.com"
+			return false
+		}
+	}
+	return true
+}
+
+// connectMethod is the map key (in its String form) for keeping persistent
+// TCP connections alive for subsequent HTTP requests.
+//
+// A connect method may be of the following types:
+//
+// Cache key form                Description
+// -----------------             -------------------------
+// |http|foo.com                 http directly to server, no proxy
+// |https|foo.com                https directly to server, no proxy
+// http://proxy.com|https|foo.com  http to proxy, then CONNECT to foo.com
+// http://proxy.com|http           http to proxy, http to anywhere after that
+//
+// Note: no support to https to the proxy yet.
+//
+type connectMethod struct {
+	proxyURL     *url.URL // nil for no proxy, else full proxy URL
+	targetScheme string   // "http" or "https"
+	targetAddr   string   // Not used if proxy + http targetScheme (4th example in table)
+}
+
+func (cm *connectMethod) key() connectMethodKey {
+	proxyStr := ""
+	targetAddr := cm.targetAddr
+	if cm.proxyURL != nil {
+		proxyStr = cm.proxyURL.String()
+		if cm.targetScheme == "http" {
+			targetAddr = ""
+		}
+	}
+	return connectMethodKey{
+		proxy:  proxyStr,
+		scheme: cm.targetScheme,
+		addr:   targetAddr,
+	}
+}
+
+// addr returns the first hop "host:port" to which we need to TCP connect.
+func (cm *connectMethod) addr() string {
+	if cm.proxyURL != nil {
+		return canonicalAddr(cm.proxyURL)
+	}
+	return cm.targetAddr
+}
+
+// tlsHost returns the host name to match against the peer's
+// TLS certificate.
+func (cm *connectMethod) tlsHost() string {
+	h := cm.targetAddr
+	if hasPort(h) {
+		h = h[:strings.LastIndex(h, ":")]
+	}
+	return h
+}
+
+// connectMethodKey is the map key version of connectMethod, with a
+// stringified proxy URL (or the empty string) instead of a pointer to
+// a URL.
+type connectMethodKey struct {
+	proxy, scheme, addr string
+}
+
+func (k connectMethodKey) String() string {
+	// Only used by tests.
+	return fmt.Sprintf("%s|%s|%s", k.proxy, k.scheme, k.addr)
+}
+
+// persistConn wraps a connection, usually a persistent one
+// (but may be used for non-keep-alive requests as well)
+type persistConn struct {
+	t        *Transport
+	cacheKey connectMethodKey
+	conn     net.Conn
+	tlsState *tls.ConnectionState
+	br       *bufio.Reader       // from conn
+	sawEOF   bool                // whether we've seen EOF from conn; owned by readLoop
+	bw       *bufio.Writer       // to conn
+	reqch    chan requestAndChan // written by roundTrip; read by readLoop
+	writech  chan writeRequest   // written by roundTrip; read by writeLoop
+	closech  chan struct{}       // closed when conn closed
+	isProxy  bool
+	// writeErrCh passes the request write error (usually nil)
+	// from the writeLoop goroutine to the readLoop which passes
+	// it off to the res.Body reader, which then uses it to decide
+	// whether or not a connection can be reused. Issue 7569.
+	writeErrCh chan error
+
+	lk                   sync.Mutex // guards following fields
+	numExpectedResponses int
+	closed               bool // whether conn has been closed
+	broken               bool // an error has happened on this connection; marked broken so it's not reused.
+	// mutateHeaderFunc is an optional func to modify extra
+	// headers on each outbound request before it's written. (the
+	// original Request given to RoundTrip is not modified)
+	mutateHeaderFunc func(Header)
+}
+
+// isBroken reports whether this connection is in a known broken state.
+func (pc *persistConn) isBroken() bool {
+	pc.lk.Lock()
+	b := pc.broken
+	pc.lk.Unlock()
+	return b
+}
+
+func (pc *persistConn) cancelRequest() {
+	pc.conn.Close()
+}
+
+var remoteSideClosedFunc func(error) bool // or nil to use default
+
+func remoteSideClosed(err error) bool {
+	if err == io.EOF {
+		return true
+	}
+	if remoteSideClosedFunc != nil {
+		return remoteSideClosedFunc(err)
+	}
+	return false
+}
+
+func (pc *persistConn) readLoop() {
+	alive := true
+
+	for alive {
+		pb, err := pc.br.Peek(1)
+
+		pc.lk.Lock()
+		if pc.numExpectedResponses == 0 {
+			if !pc.closed {
+				pc.closeLocked()
+				if len(pb) > 0 {
+					log.Printf("Unsolicited response received on idle HTTP channel starting with %q; err=%v",
+						string(pb), err)
+				}
+			}
+			pc.lk.Unlock()
+			return
+		}
+		pc.lk.Unlock()
+
+		rc := <-pc.reqch
+
+		var resp *Response
+		if err == nil {
+			resp, err = ReadResponse(pc.br, rc.req)
+			if err == nil && resp.StatusCode == 100 {
+				// Skip any 100-continue for now.
+				// TODO(bradfitz): if rc.req had "Expect: 100-continue",
+				// actually block the request body write and signal the
+				// writeLoop now to begin sending it. (Issue 2184) For now we
+				// eat it, since we're never expecting one.
+				resp, err = ReadResponse(pc.br, rc.req)
+			}
+		}
+
+		if resp != nil {
+			resp.TLS = pc.tlsState
+		}
+
+		hasBody := resp != nil && rc.req.Method != "HEAD" && resp.ContentLength != 0
+
+		if err != nil {
+			pc.close()
+		} else {
+			if rc.addedGzip && hasBody && resp.Header.Get("Content-Encoding") == "gzip" {
+				resp.Header.Del("Content-Encoding")
+				resp.Header.Del("Content-Length")
+				resp.ContentLength = -1
+				resp.Body = &gzipReader{body: resp.Body}
+			}
+			resp.Body = &bodyEOFSignal{body: resp.Body}
+		}
+
+		if err != nil || resp.Close || rc.req.Close || resp.StatusCode <= 199 {
+			// Don't do keep-alive on error if either party requested a close
+			// or we get an unexpected informational (1xx) response.
+			// StatusCode 100 is already handled above.
+			alive = false
+		}
+
+		var waitForBodyRead chan bool
+		if hasBody {
+			waitForBodyRead = make(chan bool, 2)
+			resp.Body.(*bodyEOFSignal).earlyCloseFn = func() error {
+				// Sending false here sets alive to
+				// false and closes the connection
+				// below.
+				waitForBodyRead <- false
+				return nil
+			}
+			resp.Body.(*bodyEOFSignal).fn = func(err error) {
+				waitForBodyRead <- alive &&
+					err == nil &&
+					!pc.sawEOF &&
+					pc.wroteRequest() &&
+					pc.t.putIdleConn(pc)
+			}
+		}
+
+		if alive && !hasBody {
+			alive = !pc.sawEOF &&
+				pc.wroteRequest() &&
+				pc.t.putIdleConn(pc)
+		}
+
+		rc.ch <- responseAndError{resp, err}
+
+		// Wait for the just-returned response body to be fully consumed
+		// before we race and peek on the underlying bufio reader.
+		if waitForBodyRead != nil {
+			select {
+			case alive = <-waitForBodyRead:
+			case <-pc.closech:
+				alive = false
+			}
+		}
+
+		pc.t.setReqCanceler(rc.req, nil)
+
+		if !alive {
+			pc.close()
+		}
+	}
+}
+
+func (pc *persistConn) writeLoop() {
+	for {
+		select {
+		case wr := <-pc.writech:
+			if pc.isBroken() {
+				wr.ch <- errors.New("http: can't write HTTP request on broken connection")
+				continue
+			}
+			err := wr.req.Request.write(pc.bw, pc.isProxy, wr.req.extra)
+			if err == nil {
+				err = pc.bw.Flush()
+			}
+			if err != nil {
+				pc.markBroken()
+				wr.req.Request.closeBody()
+			}
+			pc.writeErrCh <- err // to the body reader, which might recycle us
+			wr.ch <- err         // to the roundTrip function
+		case <-pc.closech:
+			return
+		}
+	}
+}
+
+// wroteRequest is a check before recycling a connection that the previous write
+// (from writeLoop above) happened and was successful.
+func (pc *persistConn) wroteRequest() bool {
+	select {
+	case err := <-pc.writeErrCh:
+		// Common case: the write happened well before the response, so
+		// avoid creating a timer.
+		return err == nil
+	default:
+		// Rare case: the request was written in writeLoop above but
+		// before it could send to pc.writeErrCh, the reader read it
+		// all, processed it, and called us here. In this case, give the
+		// write goroutine a bit of time to finish its send.
+		//
+		// Less rare case: We also get here in the legitimate case of
+		// Issue 7569, where the writer is still writing (or stalled),
+		// but the server has already replied. In this case, we don't
+		// want to wait too long, and we want to return false so this
+		// connection isn't re-used.
+		select {
+		case err := <-pc.writeErrCh:
+			return err == nil
+		case <-time.After(50 * time.Millisecond):
+			return false
+		}
+	}
+}
+
+type responseAndError struct {
+	res *Response
+	err error
+}
+
+type requestAndChan struct {
+	req *Request
+	ch  chan responseAndError
+
+	// did the Transport (as opposed to the client code) add an
+	// Accept-Encoding gzip header? only if it we set it do
+	// we transparently decode the gzip.
+	addedGzip bool
+}
+
+// A writeRequest is sent by the readLoop's goroutine to the
+// writeLoop's goroutine to write a request while the read loop
+// concurrently waits on both the write response and the server's
+// reply.
+type writeRequest struct {
+	req *transportRequest
+	ch  chan<- error
+}
+
+type httpError struct {
+	err     string
+	timeout bool
+}
+
+func (e *httpError) Error() string   { return e.err }
+func (e *httpError) Timeout() bool   { return e.timeout }
+func (e *httpError) Temporary() bool { return true }
+
+var errTimeout error = &httpError{err: "net/http: timeout awaiting response headers", timeout: true}
+var errClosed error = &httpError{err: "net/http: transport closed before response was received"}
+
+func (pc *persistConn) roundTrip(req *transportRequest) (resp *Response, err error) {
+	pc.t.setReqCanceler(req.Request, pc.cancelRequest)
+	pc.lk.Lock()
+	pc.numExpectedResponses++
+	headerFn := pc.mutateHeaderFunc
+	pc.lk.Unlock()
+
+	if headerFn != nil {
+		headerFn(req.extraHeaders())
+	}
+
+	// Ask for a compressed version if the caller didn't set their
+	// own value for Accept-Encoding. We only attempted to
+	// uncompress the gzip stream if we were the layer that
+	// requested it.
+	requestedGzip := false
+	if !pc.t.DisableCompression && req.Header.Get("Accept-Encoding") == "" && req.Method != "HEAD" {
+		// Request gzip only, not deflate. Deflate is ambiguous and
+		// not as universally supported anyway.
+		// See: http://www.gzip.org/zlib/zlib_faq.html#faq38
+		//
+		// Note that we don't request this for HEAD requests,
+		// due to a bug in nginx:
+		//   http://trac.nginx.org/nginx/ticket/358
+		//   http://golang.org/issue/5522
+		requestedGzip = true
+		req.extraHeaders().Set("Accept-Encoding", "gzip")
+	}
+
+	// Write the request concurrently with waiting for a response,
+	// in case the server decides to reply before reading our full
+	// request body.
+	writeErrCh := make(chan error, 1)
+	pc.writech <- writeRequest{req, writeErrCh}
+
+	resc := make(chan responseAndError, 1)
+	pc.reqch <- requestAndChan{req.Request, resc, requestedGzip}
+
+	var re responseAndError
+	var pconnDeadCh = pc.closech
+	var failTicker <-chan time.Time
+	var respHeaderTimer <-chan time.Time
+WaitResponse:
+	for {
+		select {
+		case err := <-writeErrCh:
+			if err != nil {
+				re = responseAndError{nil, err}
+				pc.close()
+				break WaitResponse
+			}
+			if d := pc.t.ResponseHeaderTimeout; d > 0 {
+				respHeaderTimer = time.After(d)
+			}
+		case <-pconnDeadCh:
+			// The persist connection is dead. This shouldn't
+			// usually happen (only with Connection: close responses
+			// with no response bodies), but if it does happen it
+			// means either a) the remote server hung up on us
+			// prematurely, or b) the readLoop sent us a response &
+			// closed its closech at roughly the same time, and we
+			// selected this case first, in which case a response
+			// might still be coming soon.
+			//
+			// We can't avoid the select race in b) by using a unbuffered
+			// resc channel instead, because then goroutines can
+			// leak if we exit due to other errors.
+			pconnDeadCh = nil                               // avoid spinning
+			failTicker = time.After(100 * time.Millisecond) // arbitrary time to wait for resc
+		case <-failTicker:
+			re = responseAndError{err: errClosed}
+			break WaitResponse
+		case <-respHeaderTimer:
+			pc.close()
+			re = responseAndError{err: errTimeout}
+			break WaitResponse
+		case re = <-resc:
+			break WaitResponse
+		}
+	}
+
+	pc.lk.Lock()
+	pc.numExpectedResponses--
+	pc.lk.Unlock()
+
+	if re.err != nil {
+		pc.t.setReqCanceler(req.Request, nil)
+	}
+	return re.res, re.err
+}
+
+// markBroken marks a connection as broken (so it's not reused).
+// It differs from close in that it doesn't close the underlying
+// connection for use when it's still being read.
+func (pc *persistConn) markBroken() {
+	pc.lk.Lock()
+	defer pc.lk.Unlock()
+	pc.broken = true
+}
+
+func (pc *persistConn) close() {
+	pc.lk.Lock()
+	defer pc.lk.Unlock()
+	pc.closeLocked()
+}
+
+func (pc *persistConn) closeLocked() {
+	pc.broken = true
+	if !pc.closed {
+		pc.conn.Close()
+		pc.closed = true
+		close(pc.closech)
+	}
+	pc.mutateHeaderFunc = nil
+}
+
+var portMap = map[string]string{
+	"http":  "80",
+	"https": "443",
+}
+
+// canonicalAddr returns url.Host but always with a ":port" suffix
+func canonicalAddr(url *url.URL) string {
+	addr := url.Host
+	if !hasPort(addr) {
+		return addr + ":" + portMap[url.Scheme]
+	}
+	return addr
+}
+
+// bodyEOFSignal wraps a ReadCloser but runs fn (if non-nil) at most
+// once, right before its final (error-producing) Read or Close call
+// returns. If earlyCloseFn is non-nil and Close is called before
+// io.EOF is seen, earlyCloseFn is called instead of fn, and its
+// return value is the return value from Close.
+type bodyEOFSignal struct {
+	body         io.ReadCloser
+	mu           sync.Mutex   // guards following 4 fields
+	closed       bool         // whether Close has been called
+	rerr         error        // sticky Read error
+	fn           func(error)  // error will be nil on Read io.EOF
+	earlyCloseFn func() error // optional alt Close func used if io.EOF not seen
+}
+
+func (es *bodyEOFSignal) Read(p []byte) (n int, err error) {
+	es.mu.Lock()
+	closed, rerr := es.closed, es.rerr
+	es.mu.Unlock()
+	if closed {
+		return 0, errors.New("http: read on closed response body")
+	}
+	if rerr != nil {
+		return 0, rerr
+	}
+
+	n, err = es.body.Read(p)
+	if err != nil {
+		es.mu.Lock()
+		defer es.mu.Unlock()
+		if es.rerr == nil {
+			es.rerr = err
+		}
+		es.condfn(err)
+	}
+	return
+}
+
+func (es *bodyEOFSignal) Close() error {
+	es.mu.Lock()
+	defer es.mu.Unlock()
+	if es.closed {
+		return nil
+	}
+	es.closed = true
+	if es.earlyCloseFn != nil && es.rerr != io.EOF {
+		return es.earlyCloseFn()
+	}
+	err := es.body.Close()
+	es.condfn(err)
+	return err
+}
+
+// caller must hold es.mu.
+func (es *bodyEOFSignal) condfn(err error) {
+	if es.fn == nil {
+		return
+	}
+	if err == io.EOF {
+		err = nil
+	}
+	es.fn(err)
+	es.fn = nil
+}
+
+// gzipReader wraps a response body so it can lazily
+// call gzip.NewReader on the first call to Read
+type gzipReader struct {
+	body io.ReadCloser // underlying Response.Body
+	zr   io.Reader     // lazily-initialized gzip reader
+}
+
+func (gz *gzipReader) Read(p []byte) (n int, err error) {
+	if gz.zr == nil {
+		gz.zr, err = gzip.NewReader(gz.body)
+		if err != nil {
+			return 0, err
+		}
+	}
+	return gz.zr.Read(p)
+}
+
+func (gz *gzipReader) Close() error {
+	return gz.body.Close()
+}
+
+type readerAndCloser struct {
+	io.Reader
+	io.Closer
+}
+
+type tlsHandshakeTimeoutError struct{}
+
+func (tlsHandshakeTimeoutError) Timeout() bool   { return true }
+func (tlsHandshakeTimeoutError) Temporary() bool { return true }
+func (tlsHandshakeTimeoutError) Error() string   { return "net/http: TLS handshake timeout" }
+
+type noteEOFReader struct {
+	r      io.Reader
+	sawEOF *bool
+}
+
+func (nr noteEOFReader) Read(p []byte) (n int, err error) {
+	n, err = nr.r.Read(p)
+	if err == io.EOF {
+		*nr.sawEOF = true
+	}
+	return
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/http/triv.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/triv.go
new file mode 100644
index 000000000..232d65089
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/http/triv.go
@@ -0,0 +1,141 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build ignore
+
+package main
+
+import (
+	"bytes"
+	"expvar"
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"os"
+	"os/exec"
+	"strconv"
+	"sync"
+)
+
+// hello world, the web server
+var helloRequests = expvar.NewInt("hello-requests")
+
+func HelloServer(w http.ResponseWriter, req *http.Request) {
+	helloRequests.Add(1)
+	io.WriteString(w, "hello, world!\n")
+}
+
+// Simple counter server. POSTing to it will set the value.
+type Counter struct {
+	mu sync.Mutex // protects n
+	n  int
+}
+
+// This makes Counter satisfy the expvar.Var interface, so we can export
+// it directly.
+func (ctr *Counter) String() string {
+	ctr.mu.Lock()
+	defer ctr.mu.Unlock()
+	return fmt.Sprintf("%d", ctr.n)
+}
+
+func (ctr *Counter) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	ctr.mu.Lock()
+	defer ctr.mu.Unlock()
+	switch req.Method {
+	case "GET":
+		ctr.n++
+	case "POST":
+		buf := new(bytes.Buffer)
+		io.Copy(buf, req.Body)
+		body := buf.String()
+		if n, err := strconv.Atoi(body); err != nil {
+			fmt.Fprintf(w, "bad POST: %v\nbody: [%v]\n", err, body)
+		} else {
+			ctr.n = n
+			fmt.Fprint(w, "counter reset\n")
+		}
+	}
+	fmt.Fprintf(w, "counter = %d\n", ctr.n)
+}
+
+// simple flag server
+var booleanflag = flag.Bool("boolean", true, "another flag for testing")
+
+func FlagServer(w http.ResponseWriter, req *http.Request) {
+	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+	fmt.Fprint(w, "Flags:\n")
+	flag.VisitAll(func(f *flag.Flag) {
+		if f.Value.String() != f.DefValue {
+			fmt.Fprintf(w, "%s = %s [default = %s]\n", f.Name, f.Value.String(), f.DefValue)
+		} else {
+			fmt.Fprintf(w, "%s = %s\n", f.Name, f.Value.String())
+		}
+	})
+}
+
+// simple argument server
+func ArgServer(w http.ResponseWriter, req *http.Request) {
+	for _, s := range os.Args {
+		fmt.Fprint(w, s, " ")
+	}
+}
+
+// a channel (just for the fun of it)
+type Chan chan int
+
+func ChanCreate() Chan {
+	c := make(Chan)
+	go func(c Chan) {
+		for x := 0; ; x++ {
+			c <- x
+		}
+	}(c)
+	return c
+}
+
+func (ch Chan) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	io.WriteString(w, fmt.Sprintf("channel send #%d\n", <-ch))
+}
+
+// exec a program, redirecting output
+func DateServer(rw http.ResponseWriter, req *http.Request) {
+	rw.Header().Set("Content-Type", "text/plain; charset=utf-8")
+
+	date, err := exec.Command("/bin/date").Output()
+	if err != nil {
+		http.Error(rw, err.Error(), 500)
+		return
+	}
+	rw.Write(date)
+}
+
+func Logger(w http.ResponseWriter, req *http.Request) {
+	log.Print(req.URL)
+	http.Error(w, "oops", 404)
+}
+
+var webroot = flag.String("root", os.Getenv("HOME"), "web root directory")
+
+func main() {
+	flag.Parse()
+
+	// The counter is published as a variable directly.
+	ctr := new(Counter)
+	expvar.Publish("counter", ctr)
+	http.Handle("/counter", ctr)
+	http.Handle("/", http.HandlerFunc(Logger))
+	http.Handle("/go/", http.StripPrefix("/go/", http.FileServer(http.Dir(*webroot))))
+	http.Handle("/chan", ChanCreate())
+	http.HandleFunc("/flags", FlagServer)
+	http.HandleFunc("/args", ArgServer)
+	http.HandleFunc("/go/hello", HelloServer)
+	http.HandleFunc("/date", DateServer)
+	err := http.ListenAndServe(":12345", nil)
+	if err != nil {
+		log.Panicln("ListenAndServe:", err)
+	}
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/alert.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/alert.go
new file mode 100644
index 000000000..0856311e4
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/alert.go
@@ -0,0 +1,77 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package tls
+
+import "strconv"
+
+type alert uint8
+
+const (
+	// alert level
+	alertLevelWarning = 1
+	alertLevelError   = 2
+)
+
+const (
+	alertCloseNotify            alert = 0
+	alertUnexpectedMessage      alert = 10
+	alertBadRecordMAC           alert = 20
+	alertDecryptionFailed       alert = 21
+	alertRecordOverflow         alert = 22
+	alertDecompressionFailure   alert = 30
+	alertHandshakeFailure       alert = 40
+	alertBadCertificate         alert = 42
+	alertUnsupportedCertificate alert = 43
+	alertCertificateRevoked     alert = 44
+	alertCertificateExpired     alert = 45
+	alertCertificateUnknown     alert = 46
+	alertIllegalParameter       alert = 47
+	alertUnknownCA              alert = 48
+	alertAccessDenied           alert = 49
+	alertDecodeError            alert = 50
+	alertDecryptError           alert = 51
+	alertProtocolVersion        alert = 70
+	alertInsufficientSecurity   alert = 71
+	alertInternalError          alert = 80
+	alertUserCanceled           alert = 90
+	alertNoRenegotiation        alert = 100
+)
+
+var alertText = map[alert]string{
+	alertCloseNotify:            "close notify",
+	alertUnexpectedMessage:      "unexpected message",
+	alertBadRecordMAC:           "bad record MAC",
+	alertDecryptionFailed:       "decryption failed",
+	alertRecordOverflow:         "record overflow",
+	alertDecompressionFailure:   "decompression failure",
+	alertHandshakeFailure:       "handshake failure",
+	alertBadCertificate:         "bad certificate",
+	alertUnsupportedCertificate: "unsupported certificate",
+	alertCertificateRevoked:     "revoked certificate",
+	alertCertificateExpired:     "expired certificate",
+	alertCertificateUnknown:     "unknown certificate",
+	alertIllegalParameter:       "illegal parameter",
+	alertUnknownCA:              "unknown certificate authority",
+	alertAccessDenied:           "access denied",
+	alertDecodeError:            "error decoding message",
+	alertDecryptError:           "error decrypting message",
+	alertProtocolVersion:        "protocol version not supported",
+	alertInsufficientSecurity:   "insufficient security level",
+	alertInternalError:          "internal error",
+	alertUserCanceled:           "user canceled",
+	alertNoRenegotiation:        "no renegotiation",
+}
+
+func (e alert) String() string {
+	s, ok := alertText[e]
+	if ok {
+		return s
+	}
+	return "alert(" + strconv.Itoa(int(e)) + ")"
+}
+
+func (e alert) Error() string {
+	return e.String()
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/cipher_suites.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/cipher_suites.go
new file mode 100644
index 000000000..39a51459d
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/cipher_suites.go
@@ -0,0 +1,270 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package tls
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/des"
+	"crypto/hmac"
+	"crypto/rc4"
+	"crypto/sha1"
+	"crypto/x509"
+	"hash"
+)
+
+// a keyAgreement implements the client and server side of a TLS key agreement
+// protocol by generating and processing key exchange messages.
+type keyAgreement interface {
+	// On the server side, the first two methods are called in order.
+
+	// In the case that the key agreement protocol doesn't use a
+	// ServerKeyExchange message, generateServerKeyExchange can return nil,
+	// nil.
+	generateServerKeyExchange(*Config, *Certificate, *clientHelloMsg, *serverHelloMsg) (*serverKeyExchangeMsg, error)
+	processClientKeyExchange(*Config, *Certificate, *clientKeyExchangeMsg, uint16) ([]byte, error)
+
+	// On the client side, the next two methods are called in order.
+
+	// This method may not be called if the server doesn't send a
+	// ServerKeyExchange message.
+	processServerKeyExchange(*Config, *clientHelloMsg, *serverHelloMsg, *x509.Certificate, *serverKeyExchangeMsg) error
+	generateClientKeyExchange(*Config, *clientHelloMsg, *x509.Certificate) ([]byte, *clientKeyExchangeMsg, error)
+}
+
+const (
+	// suiteECDH indicates that the cipher suite involves elliptic curve
+	// Diffie-Hellman. This means that it should only be selected when the
+	// client indicates that it supports ECC with a curve and point format
+	// that we're happy with.
+	suiteECDHE = 1 << iota
+	// suiteECDSA indicates that the cipher suite involves an ECDSA
+	// signature and therefore may only be selected when the server's
+	// certificate is ECDSA. If this is not set then the cipher suite is
+	// RSA based.
+	suiteECDSA
+	// suiteTLS12 indicates that the cipher suite should only be advertised
+	// and accepted when using TLS 1.2.
+	suiteTLS12
+)
+
+// A cipherSuite is a specific combination of key agreement, cipher and MAC
+// function. All cipher suites currently assume RSA key agreement.
+type cipherSuite struct {
+	id uint16
+	// the lengths, in bytes, of the key material needed for each component.
+	keyLen int
+	macLen int
+	ivLen  int
+	ka     func(version uint16) keyAgreement
+	// flags is a bitmask of the suite* values, above.
+	flags  int
+	cipher func(key, iv []byte, isRead bool) interface{}
+	mac    func(version uint16, macKey []byte) macFunction
+	aead   func(key, fixedNonce []byte) cipher.AEAD
+}
+
+var cipherSuites = []*cipherSuite{
+	// Ciphersuite order is chosen so that ECDHE comes before plain RSA
+	// and RC4 comes before AES (because of the Lucky13 attack).
+	{TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, 16, 0, 4, ecdheRSAKA, suiteECDHE | suiteTLS12, nil, nil, aeadAESGCM},
+	{TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, 16, 0, 4, ecdheECDSAKA, suiteECDHE | suiteECDSA | suiteTLS12, nil, nil, aeadAESGCM},
+	{TLS_ECDHE_RSA_WITH_RC4_128_SHA, 16, 20, 0, ecdheRSAKA, suiteECDHE, cipherRC4, macSHA1, nil},
+	{TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, 16, 20, 0, ecdheECDSAKA, suiteECDHE | suiteECDSA, cipherRC4, macSHA1, nil},
+	{TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, 16, 20, 16, ecdheRSAKA, suiteECDHE, cipherAES, macSHA1, nil},
+	{TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, 16, 20, 16, ecdheECDSAKA, suiteECDHE | suiteECDSA, cipherAES, macSHA1, nil},
+	{TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA, 32, 20, 16, ecdheRSAKA, suiteECDHE, cipherAES, macSHA1, nil},
+	{TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA, 32, 20, 16, ecdheECDSAKA, suiteECDHE | suiteECDSA, cipherAES, macSHA1, nil},
+	{TLS_RSA_WITH_RC4_128_SHA, 16, 20, 0, rsaKA, 0, cipherRC4, macSHA1, nil},
+	{TLS_RSA_WITH_AES_128_CBC_SHA, 16, 20, 16, rsaKA, 0, cipherAES, macSHA1, nil},
+	{TLS_RSA_WITH_AES_256_CBC_SHA, 32, 20, 16, rsaKA, 0, cipherAES, macSHA1, nil},
+	{TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA, 24, 20, 8, ecdheRSAKA, suiteECDHE, cipher3DES, macSHA1, nil},
+	{TLS_RSA_WITH_3DES_EDE_CBC_SHA, 24, 20, 8, rsaKA, 0, cipher3DES, macSHA1, nil},
+}
+
+func cipherRC4(key, iv []byte, isRead bool) interface{} {
+	cipher, _ := rc4.NewCipher(key)
+	return cipher
+}
+
+func cipher3DES(key, iv []byte, isRead bool) interface{} {
+	block, _ := des.NewTripleDESCipher(key)
+	if isRead {
+		return cipher.NewCBCDecrypter(block, iv)
+	}
+	return cipher.NewCBCEncrypter(block, iv)
+}
+
+func cipherAES(key, iv []byte, isRead bool) interface{} {
+	block, _ := aes.NewCipher(key)
+	if isRead {
+		return cipher.NewCBCDecrypter(block, iv)
+	}
+	return cipher.NewCBCEncrypter(block, iv)
+}
+
+// macSHA1 returns a macFunction for the given protocol version.
+func macSHA1(version uint16, key []byte) macFunction {
+	if version == VersionSSL30 {
+		mac := ssl30MAC{
+			h:   sha1.New(),
+			key: make([]byte, len(key)),
+		}
+		copy(mac.key, key)
+		return mac
+	}
+	return tls10MAC{hmac.New(sha1.New, key)}
+}
+
+type macFunction interface {
+	Size() int
+	MAC(digestBuf, seq, header, data []byte) []byte
+}
+
+// fixedNonceAEAD wraps an AEAD and prefixes a fixed portion of the nonce to
+// each call.
+type fixedNonceAEAD struct {
+	// sealNonce and openNonce are buffers where the larger nonce will be
+	// constructed. Since a seal and open operation may be running
+	// concurrently, there is a separate buffer for each.
+	sealNonce, openNonce []byte
+	aead                 cipher.AEAD
+}
+
+func (f *fixedNonceAEAD) NonceSize() int { return 8 }
+func (f *fixedNonceAEAD) Overhead() int  { return f.aead.Overhead() }
+
+func (f *fixedNonceAEAD) Seal(out, nonce, plaintext, additionalData []byte) []byte {
+	copy(f.sealNonce[len(f.sealNonce)-8:], nonce)
+	return f.aead.Seal(out, f.sealNonce, plaintext, additionalData)
+}
+
+func (f *fixedNonceAEAD) Open(out, nonce, plaintext, additionalData []byte) ([]byte, error) {
+	copy(f.openNonce[len(f.openNonce)-8:], nonce)
+	return f.aead.Open(out, f.openNonce, plaintext, additionalData)
+}
+
+func aeadAESGCM(key, fixedNonce []byte) cipher.AEAD {
+	aes, err := aes.NewCipher(key)
+	if err != nil {
+		panic(err)
+	}
+	aead, err := cipher.NewGCM(aes)
+	if err != nil {
+		panic(err)
+	}
+
+	nonce1, nonce2 := make([]byte, 12), make([]byte, 12)
+	copy(nonce1, fixedNonce)
+	copy(nonce2, fixedNonce)
+
+	return &fixedNonceAEAD{nonce1, nonce2, aead}
+}
+
+// ssl30MAC implements the SSLv3 MAC function, as defined in
+// www.mozilla.org/projects/security/pki/nss/ssl/draft302.txt section 5.2.3.1
+type ssl30MAC struct {
+	h   hash.Hash
+	key []byte
+}
+
+func (s ssl30MAC) Size() int {
+	return s.h.Size()
+}
+
+var ssl30Pad1 = [48]byte{0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36}
+
+var ssl30Pad2 = [48]byte{0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c}
+
+func (s ssl30MAC) MAC(digestBuf, seq, header, data []byte) []byte {
+	padLength := 48
+	if s.h.Size() == 20 {
+		padLength = 40
+	}
+
+	s.h.Reset()
+	s.h.Write(s.key)
+	s.h.Write(ssl30Pad1[:padLength])
+	s.h.Write(seq)
+	s.h.Write(header[:1])
+	s.h.Write(header[3:5])
+	s.h.Write(data)
+	digestBuf = s.h.Sum(digestBuf[:0])
+
+	s.h.Reset()
+	s.h.Write(s.key)
+	s.h.Write(ssl30Pad2[:padLength])
+	s.h.Write(digestBuf)
+	return s.h.Sum(digestBuf[:0])
+}
+
+// tls10MAC implements the TLS 1.0 MAC function. RFC 2246, section 6.2.3.
+type tls10MAC struct {
+	h hash.Hash
+}
+
+func (s tls10MAC) Size() int {
+	return s.h.Size()
+}
+
+func (s tls10MAC) MAC(digestBuf, seq, header, data []byte) []byte {
+	s.h.Reset()
+	s.h.Write(seq)
+	s.h.Write(header)
+	s.h.Write(data)
+	return s.h.Sum(digestBuf[:0])
+}
+
+func rsaKA(version uint16) keyAgreement {
+	return rsaKeyAgreement{}
+}
+
+func ecdheECDSAKA(version uint16) keyAgreement {
+	return &ecdheKeyAgreement{
+		sigType: signatureECDSA,
+		version: version,
+	}
+}
+
+func ecdheRSAKA(version uint16) keyAgreement {
+	return &ecdheKeyAgreement{
+		sigType: signatureRSA,
+		version: version,
+	}
+}
+
+// mutualCipherSuite returns a cipherSuite given a list of supported
+// ciphersuites and the id requested by the peer.
+func mutualCipherSuite(have []uint16, want uint16) *cipherSuite {
+	for _, id := range have {
+		if id == want {
+			for _, suite := range cipherSuites {
+				if suite.id == want {
+					return suite
+				}
+			}
+			return nil
+		}
+	}
+	return nil
+}
+
+// A list of the possible cipher suite ids. Taken from
+// http://www.iana.org/assignments/tls-parameters/tls-parameters.xml
+const (
+	TLS_RSA_WITH_RC4_128_SHA                uint16 = 0x0005
+	TLS_RSA_WITH_3DES_EDE_CBC_SHA           uint16 = 0x000a
+	TLS_RSA_WITH_AES_128_CBC_SHA            uint16 = 0x002f
+	TLS_RSA_WITH_AES_256_CBC_SHA            uint16 = 0x0035
+	TLS_ECDHE_ECDSA_WITH_RC4_128_SHA        uint16 = 0xc007
+	TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA    uint16 = 0xc009
+	TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA    uint16 = 0xc00a
+	TLS_ECDHE_RSA_WITH_RC4_128_SHA          uint16 = 0xc011
+	TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA     uint16 = 0xc012
+	TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA      uint16 = 0xc013
+	TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA      uint16 = 0xc014
+	TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256   uint16 = 0xc02f
+	TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 uint16 = 0xc02b
+)
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/common.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/common.go
new file mode 100644
index 000000000..7eb283c5a
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/common.go
@@ -0,0 +1,438 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package tls
+
+import (
+	"crypto"
+	"crypto/rand"
+	"crypto/x509"
+	"io"
+	"math/big"
+	"strings"
+	"sync"
+	"time"
+)
+
+const (
+	VersionSSL30 = 0x0300
+	VersionTLS10 = 0x0301
+	VersionTLS11 = 0x0302
+	VersionTLS12 = 0x0303
+)
+
+const (
+	maxPlaintext    = 16384        // maximum plaintext payload length
+	maxCiphertext   = 16384 + 2048 // maximum ciphertext payload length
+	recordHeaderLen = 5            // record header length
+	maxHandshake    = 65536        // maximum handshake we support (protocol max is 16 MB)
+
+	minVersion = VersionSSL30
+	maxVersion = VersionTLS12
+)
+
+// TLS record types.
+type recordType uint8
+
+const (
+	recordTypeChangeCipherSpec recordType = 20
+	recordTypeAlert            recordType = 21
+	recordTypeHandshake        recordType = 22
+	recordTypeApplicationData  recordType = 23
+)
+
+// TLS handshake message types.
+const (
+	typeHelloRequest       uint8 = 0
+	typeClientHello        uint8 = 1
+	typeServerHello        uint8 = 2
+	typeNewSessionTicket   uint8 = 4
+	typeCertificate        uint8 = 11
+	typeServerKeyExchange  uint8 = 12
+	typeCertificateRequest uint8 = 13
+	typeServerHelloDone    uint8 = 14
+	typeCertificateVerify  uint8 = 15
+	typeClientKeyExchange  uint8 = 16
+	typeFinished           uint8 = 20
+	typeCertificateStatus  uint8 = 22
+	typeNextProtocol       uint8 = 67 // Not IANA assigned
+)
+
+// TLS compression types.
+const (
+	compressionNone uint8 = 0
+)
+
+// TLS extension numbers
+var (
+	extensionServerName          uint16 = 0
+	extensionStatusRequest       uint16 = 5
+	extensionSupportedCurves     uint16 = 10
+	extensionSupportedPoints     uint16 = 11
+	extensionSignatureAlgorithms uint16 = 13
+	extensionSessionTicket       uint16 = 35
+	extensionNextProtoNeg        uint16 = 13172 // not IANA assigned
+)
+
+// TLS Elliptic Curves
+// http://www.iana.org/assignments/tls-parameters/tls-parameters.xml#tls-parameters-8
+var (
+	curveP256 uint16 = 23
+	curveP384 uint16 = 24
+	curveP521 uint16 = 25
+)
+
+// TLS Elliptic Curve Point Formats
+// http://www.iana.org/assignments/tls-parameters/tls-parameters.xml#tls-parameters-9
+var (
+	pointFormatUncompressed uint8 = 0
+)
+
+// TLS CertificateStatusType (RFC 3546)
+const (
+	statusTypeOCSP uint8 = 1
+)
+
+// Certificate types (for certificateRequestMsg)
+const (
+	certTypeRSASign    = 1 // A certificate containing an RSA key
+	certTypeDSSSign    = 2 // A certificate containing a DSA key
+	certTypeRSAFixedDH = 3 // A certificate containing a static DH key
+	certTypeDSSFixedDH = 4 // A certificate containing a static DH key
+
+	// See RFC4492 sections 3 and 5.5.
+	certTypeECDSASign      = 64 // A certificate containing an ECDSA-capable public key, signed with ECDSA.
+	certTypeRSAFixedECDH   = 65 // A certificate containing an ECDH-capable public key, signed with RSA.
+	certTypeECDSAFixedECDH = 66 // A certificate containing an ECDH-capable public key, signed with ECDSA.
+
+	// Rest of these are reserved by the TLS spec
+)
+
+// Hash functions for TLS 1.2 (See RFC 5246, section A.4.1)
+const (
+	hashSHA1   uint8 = 2
+	hashSHA256 uint8 = 4
+)
+
+// Signature algorithms for TLS 1.2 (See RFC 5246, section A.4.1)
+const (
+	signatureRSA   uint8 = 1
+	signatureECDSA uint8 = 3
+)
+
+// signatureAndHash mirrors the TLS 1.2, SignatureAndHashAlgorithm struct. See
+// RFC 5246, section A.4.1.
+type signatureAndHash struct {
+	hash, signature uint8
+}
+
+// supportedSKXSignatureAlgorithms contains the signature and hash algorithms
+// that the code advertises as supported in a TLS 1.2 ClientHello.
+var supportedSKXSignatureAlgorithms = []signatureAndHash{
+	{hashSHA256, signatureRSA},
+	{hashSHA256, signatureECDSA},
+	{hashSHA1, signatureRSA},
+	{hashSHA1, signatureECDSA},
+}
+
+// supportedClientCertSignatureAlgorithms contains the signature and hash
+// algorithms that the code advertises as supported in a TLS 1.2
+// CertificateRequest.
+var supportedClientCertSignatureAlgorithms = []signatureAndHash{
+	{hashSHA256, signatureRSA},
+	{hashSHA256, signatureECDSA},
+}
+
+// ConnectionState records basic TLS details about the connection.
+type ConnectionState struct {
+	HandshakeComplete          bool                  // TLS handshake is complete
+	DidResume                  bool                  // connection resumes a previous TLS connection
+	CipherSuite                uint16                // cipher suite in use (TLS_RSA_WITH_RC4_128_SHA, ...)
+	NegotiatedProtocol         string                // negotiated next protocol (from Config.NextProtos)
+	NegotiatedProtocolIsMutual bool                  // negotiated protocol was advertised by server
+	ServerName                 string                // server name requested by client, if any (server side only)
+	PeerCertificates           []*x509.Certificate   // certificate chain presented by remote peer
+	VerifiedChains             [][]*x509.Certificate // verified chains built from PeerCertificates
+}
+
+// ClientAuthType declares the policy the server will follow for
+// TLS Client Authentication.
+type ClientAuthType int
+
+const (
+	NoClientCert ClientAuthType = iota
+	RequestClientCert
+	RequireAnyClientCert
+	VerifyClientCertIfGiven
+	RequireAndVerifyClientCert
+)
+
+// A Config structure is used to configure a TLS client or server. After one
+// has been passed to a TLS function it must not be modified.
+type Config struct {
+	// Rand provides the source of entropy for nonces and RSA blinding.
+	// If Rand is nil, TLS uses the cryptographic random reader in package
+	// crypto/rand.
+	Rand io.Reader
+
+	// Time returns the current time as the number of seconds since the epoch.
+	// If Time is nil, TLS uses time.Now.
+	Time func() time.Time
+
+	// Certificates contains one or more certificate chains
+	// to present to the other side of the connection.
+	// Server configurations must include at least one certificate.
+	Certificates []Certificate
+
+	// NameToCertificate maps from a certificate name to an element of
+	// Certificates. Note that a certificate name can be of the form
+	// '*.example.com' and so doesn't have to be a domain name as such.
+	// See Config.BuildNameToCertificate
+	// The nil value causes the first element of Certificates to be used
+	// for all connections.
+	NameToCertificate map[string]*Certificate
+
+	// RootCAs defines the set of root certificate authorities
+	// that clients use when verifying server certificates.
+	// If RootCAs is nil, TLS uses the host's root CA set.
+	RootCAs *x509.CertPool
+
+	// NextProtos is a list of supported, application level protocols.
+	NextProtos []string
+
+	// ServerName is included in the client's handshake to support virtual
+	// hosting.
+	ServerName string
+
+	// ClientAuth determines the server's policy for
+	// TLS Client Authentication. The default is NoClientCert.
+	ClientAuth ClientAuthType
+
+	// ClientCAs defines the set of root certificate authorities
+	// that servers use if required to verify a client certificate
+	// by the policy in ClientAuth.
+	ClientCAs *x509.CertPool
+
+	// InsecureSkipVerify controls whether a client verifies the
+	// server's certificate chain and host name.
+	// If InsecureSkipVerify is true, TLS accepts any certificate
+	// presented by the server and any host name in that certificate.
+	// In this mode, TLS is susceptible to man-in-the-middle attacks.
+	// This should be used only for testing.
+	InsecureSkipVerify bool
+
+	// CipherSuites is a list of supported cipher suites. If CipherSuites
+	// is nil, TLS uses a list of suites supported by the implementation.
+	CipherSuites []uint16
+
+	// PreferServerCipherSuites controls whether the server selects the
+	// client's most preferred ciphersuite, or the server's most preferred
+	// ciphersuite. If true then the server's preference, as expressed in
+	// the order of elements in CipherSuites, is used.
+	PreferServerCipherSuites bool
+
+	// SessionTicketsDisabled may be set to true to disable session ticket
+	// (resumption) support.
+	SessionTicketsDisabled bool
+
+	// SessionTicketKey is used by TLS servers to provide session
+	// resumption. See RFC 5077. If zero, it will be filled with
+	// random data before the first server handshake.
+	//
+	// If multiple servers are terminating connections for the same host
+	// they should all have the same SessionTicketKey. If the
+	// SessionTicketKey leaks, previously recorded and future TLS
+	// connections using that key are compromised.
+	SessionTicketKey [32]byte
+
+	// MinVersion contains the minimum SSL/TLS version that is acceptable.
+	// If zero, then SSLv3 is taken as the minimum.
+	MinVersion uint16
+
+	// MaxVersion contains the maximum SSL/TLS version that is acceptable.
+	// If zero, then the maximum version supported by this package is used,
+	// which is currently TLS 1.2.
+	MaxVersion uint16
+
+	serverInitOnce sync.Once // guards calling (*Config).serverInit
+}
+
+func (c *Config) serverInit() {
+	if c.SessionTicketsDisabled {
+		return
+	}
+
+	// If the key has already been set then we have nothing to do.
+	for _, b := range c.SessionTicketKey {
+		if b != 0 {
+			return
+		}
+	}
+
+	if _, err := io.ReadFull(c.rand(), c.SessionTicketKey[:]); err != nil {
+		c.SessionTicketsDisabled = true
+	}
+}
+
+func (c *Config) rand() io.Reader {
+	r := c.Rand
+	if r == nil {
+		return rand.Reader
+	}
+	return r
+}
+
+func (c *Config) time() time.Time {
+	t := c.Time
+	if t == nil {
+		t = time.Now
+	}
+	return t()
+}
+
+func (c *Config) cipherSuites() []uint16 {
+	s := c.CipherSuites
+	if s == nil {
+		s = defaultCipherSuites()
+	}
+	return s
+}
+
+func (c *Config) minVersion() uint16 {
+	if c == nil || c.MinVersion == 0 {
+		return minVersion
+	}
+	return c.MinVersion
+}
+
+func (c *Config) maxVersion() uint16 {
+	if c == nil || c.MaxVersion == 0 {
+		return maxVersion
+	}
+	return c.MaxVersion
+}
+
+// mutualVersion returns the protocol version to use given the advertised
+// version of the peer.
+func (c *Config) mutualVersion(vers uint16) (uint16, bool) {
+	minVersion := c.minVersion()
+	maxVersion := c.maxVersion()
+
+	if vers < minVersion {
+		return 0, false
+	}
+	if vers > maxVersion {
+		vers = maxVersion
+	}
+	return vers, true
+}
+
+// getCertificateForName returns the best certificate for the given name,
+// defaulting to the first element of c.Certificates if there are no good
+// options.
+func (c *Config) getCertificateForName(name string) *Certificate {
+	if len(c.Certificates) == 1 || c.NameToCertificate == nil {
+		// There's only one choice, so no point doing any work.
+		return &c.Certificates[0]
+	}
+
+	name = strings.ToLower(name)
+	for len(name) > 0 && name[len(name)-1] == '.' {
+		name = name[:len(name)-1]
+	}
+
+	if cert, ok := c.NameToCertificate[name]; ok {
+		return cert
+	}
+
+	// try replacing labels in the name with wildcards until we get a
+	// match.
+	labels := strings.Split(name, ".")
+	for i := range labels {
+		labels[i] = "*"
+		candidate := strings.Join(labels, ".")
+		if cert, ok := c.NameToCertificate[candidate]; ok {
+			return cert
+		}
+	}
+
+	// If nothing matches, return the first certificate.
+	return &c.Certificates[0]
+}
+
+// BuildNameToCertificate parses c.Certificates and builds c.NameToCertificate
+// from the CommonName and SubjectAlternateName fields of each of the leaf
+// certificates.
+func (c *Config) BuildNameToCertificate() {
+	c.NameToCertificate = make(map[string]*Certificate)
+	for i := range c.Certificates {
+		cert := &c.Certificates[i]
+		x509Cert, err := x509.ParseCertificate(cert.Certificate[0])
+		if err != nil {
+			continue
+		}
+		if len(x509Cert.Subject.CommonName) > 0 {
+			c.NameToCertificate[x509Cert.Subject.CommonName] = cert
+		}
+		for _, san := range x509Cert.DNSNames {
+			c.NameToCertificate[san] = cert
+		}
+	}
+}
+
+// A Certificate is a chain of one or more certificates, leaf first.
+type Certificate struct {
+	Certificate [][]byte
+	PrivateKey  crypto.PrivateKey // supported types: *rsa.PrivateKey, *ecdsa.PrivateKey
+	// OCSPStaple contains an optional OCSP response which will be served
+	// to clients that request it.
+	OCSPStaple []byte
+	// Leaf is the parsed form of the leaf certificate, which may be
+	// initialized using x509.ParseCertificate to reduce per-handshake
+	// processing for TLS clients doing client authentication. If nil, the
+	// leaf certificate will be parsed as needed.
+	Leaf *x509.Certificate
+}
+
+// A TLS record.
+type record struct {
+	contentType  recordType
+	major, minor uint8
+	payload      []byte
+}
+
+type handshakeMessage interface {
+	marshal() []byte
+	unmarshal([]byte) bool
+}
+
+// TODO(jsing): Make these available to both crypto/x509 and crypto/tls.
+type dsaSignature struct {
+	R, S *big.Int
+}
+
+type ecdsaSignature dsaSignature
+
+var emptyConfig Config
+
+func defaultConfig() *Config {
+	return &emptyConfig
+}
+
+var (
+	once                   sync.Once
+	varDefaultCipherSuites []uint16
+)
+
+func defaultCipherSuites() []uint16 {
+	once.Do(initDefaultCipherSuites)
+	return varDefaultCipherSuites
+}
+
+func initDefaultCipherSuites() {
+	varDefaultCipherSuites = make([]uint16, len(cipherSuites))
+	for i, suite := range cipherSuites {
+		varDefaultCipherSuites[i] = suite.id
+	}
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/conn.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/conn.go
new file mode 100644
index 000000000..db036f967
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/conn.go
@@ -0,0 +1,1026 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// TLS low level connection and record layer
+
+package tls
+
+import (
+	"bytes"
+	"crypto/cipher"
+	"crypto/subtle"
+	"crypto/x509"
+	"errors"
+	"io"
+	"net"
+	"sync"
+	"time"
+)
+
+// A Conn represents a secured connection.
+// It implements the net.Conn interface.
+type Conn struct {
+	// constant
+	conn     net.Conn
+	isClient bool
+
+	// constant after handshake; protected by handshakeMutex
+	handshakeMutex    sync.Mutex // handshakeMutex < in.Mutex, out.Mutex, errMutex
+	vers              uint16     // TLS version
+	haveVers          bool       // version has been negotiated
+	config            *Config    // configuration passed to constructor
+	handshakeComplete bool
+	didResume         bool // whether this connection was a session resumption
+	cipherSuite       uint16
+	ocspResponse      []byte // stapled OCSP response
+	peerCertificates  []*x509.Certificate
+	// verifiedChains contains the certificate chains that we built, as
+	// opposed to the ones presented by the server.
+	verifiedChains [][]*x509.Certificate
+	// serverName contains the server name indicated by the client, if any.
+	serverName string
+
+	clientProtocol         string
+	clientProtocolFallback bool
+
+	// first permanent error
+	connErr
+
+	// input/output
+	in, out  halfConn     // in.Mutex < out.Mutex
+	rawInput *block       // raw input, right off the wire
+	input    *block       // application data waiting to be read
+	hand     bytes.Buffer // handshake data waiting to be read
+
+	tmp [16]byte
+}
+
+type connErr struct {
+	mu    sync.Mutex
+	value error
+}
+
+func (e *connErr) setError(err error) error {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+
+	if e.value == nil {
+		e.value = err
+	}
+	return err
+}
+
+func (e *connErr) error() error {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+	return e.value
+}
+
+// Access to net.Conn methods.
+// Cannot just embed net.Conn because that would
+// export the struct field too.
+
+// LocalAddr returns the local network address.
+func (c *Conn) LocalAddr() net.Addr {
+	return c.conn.LocalAddr()
+}
+
+// RemoteAddr returns the remote network address.
+func (c *Conn) RemoteAddr() net.Addr {
+	return c.conn.RemoteAddr()
+}
+
+// SetDeadline sets the read and write deadlines associated with the connection.
+// A zero value for t means Read and Write will not time out.
+// After a Write has timed out, the TLS state is corrupt and all future writes will return the same error.
+func (c *Conn) SetDeadline(t time.Time) error {
+	return c.conn.SetDeadline(t)
+}
+
+// SetReadDeadline sets the read deadline on the underlying connection.
+// A zero value for t means Read will not time out.
+func (c *Conn) SetReadDeadline(t time.Time) error {
+	return c.conn.SetReadDeadline(t)
+}
+
+// SetWriteDeadline sets the write deadline on the underlying conneciton.
+// A zero value for t means Write will not time out.
+// After a Write has timed out, the TLS state is corrupt and all future writes will return the same error.
+func (c *Conn) SetWriteDeadline(t time.Time) error {
+	return c.conn.SetWriteDeadline(t)
+}
+
+// A halfConn represents one direction of the record layer
+// connection, either sending or receiving.
+type halfConn struct {
+	sync.Mutex
+	version uint16      // protocol version
+	cipher  interface{} // cipher algorithm
+	mac     macFunction
+	seq     [8]byte // 64-bit sequence number
+	bfree   *block  // list of free blocks
+
+	nextCipher interface{} // next encryption state
+	nextMac    macFunction // next MAC algorithm
+
+	// used to save allocating a new buffer for each MAC.
+	inDigestBuf, outDigestBuf []byte
+}
+
+// prepareCipherSpec sets the encryption and MAC states
+// that a subsequent changeCipherSpec will use.
+func (hc *halfConn) prepareCipherSpec(version uint16, cipher interface{}, mac macFunction) {
+	hc.version = version
+	hc.nextCipher = cipher
+	hc.nextMac = mac
+}
+
+// changeCipherSpec changes the encryption and MAC states
+// to the ones previously passed to prepareCipherSpec.
+func (hc *halfConn) changeCipherSpec() error {
+	if hc.nextCipher == nil {
+		return alertInternalError
+	}
+	hc.cipher = hc.nextCipher
+	hc.mac = hc.nextMac
+	hc.nextCipher = nil
+	hc.nextMac = nil
+	for i := range hc.seq {
+		hc.seq[i] = 0
+	}
+	return nil
+}
+
+// incSeq increments the sequence number.
+func (hc *halfConn) incSeq() {
+	for i := 7; i >= 0; i-- {
+		hc.seq[i]++
+		if hc.seq[i] != 0 {
+			return
+		}
+	}
+
+	// Not allowed to let sequence number wrap.
+	// Instead, must renegotiate before it does.
+	// Not likely enough to bother.
+	panic("TLS: sequence number wraparound")
+}
+
+// resetSeq resets the sequence number to zero.
+func (hc *halfConn) resetSeq() {
+	for i := range hc.seq {
+		hc.seq[i] = 0
+	}
+}
+
+// removePadding returns an unpadded slice, in constant time, which is a prefix
+// of the input. It also returns a byte which is equal to 255 if the padding
+// was valid and 0 otherwise. See RFC 2246, section 6.2.3.2
+func removePadding(payload []byte) ([]byte, byte) {
+	if len(payload) < 1 {
+		return payload, 0
+	}
+
+	paddingLen := payload[len(payload)-1]
+	t := uint(len(payload)-1) - uint(paddingLen)
+	// if len(payload) >= (paddingLen - 1) then the MSB of t is zero
+	good := byte(int32(^t) >> 31)
+
+	toCheck := 255 // the maximum possible padding length
+	// The length of the padded data is public, so we can use an if here
+	if toCheck+1 > len(payload) {
+		toCheck = len(payload) - 1
+	}
+
+	for i := 0; i < toCheck; i++ {
+		t := uint(paddingLen) - uint(i)
+		// if i <= paddingLen then the MSB of t is zero
+		mask := byte(int32(^t) >> 31)
+		b := payload[len(payload)-1-i]
+		good &^= mask&paddingLen ^ mask&b
+	}
+
+	// We AND together the bits of good and replicate the result across
+	// all the bits.
+	good &= good << 4
+	good &= good << 2
+	good &= good << 1
+	good = uint8(int8(good) >> 7)
+
+	toRemove := good&paddingLen + 1
+	return payload[:len(payload)-int(toRemove)], good
+}
+
+// removePaddingSSL30 is a replacement for removePadding in the case that the
+// protocol version is SSLv3. In this version, the contents of the padding
+// are random and cannot be checked.
+func removePaddingSSL30(payload []byte) ([]byte, byte) {
+	if len(payload) < 1 {
+		return payload, 0
+	}
+
+	paddingLen := int(payload[len(payload)-1]) + 1
+	if paddingLen > len(payload) {
+		return payload, 0
+	}
+
+	return payload[:len(payload)-paddingLen], 255
+}
+
+func roundUp(a, b int) int {
+	return a + (b-a%b)%b
+}
+
+// cbcMode is an interface for block ciphers using cipher block chaining.
+type cbcMode interface {
+	cipher.BlockMode
+	SetIV([]byte)
+}
+
+// decrypt checks and strips the mac and decrypts the data in b. Returns a
+// success boolean, the number of bytes to skip from the start of the record in
+// order to get the application payload, and an optional alert value.
+func (hc *halfConn) decrypt(b *block) (ok bool, prefixLen int, alertValue alert) {
+	// pull out payload
+	payload := b.data[recordHeaderLen:]
+
+	macSize := 0
+	if hc.mac != nil {
+		macSize = hc.mac.Size()
+	}
+
+	paddingGood := byte(255)
+	explicitIVLen := 0
+
+	// decrypt
+	if hc.cipher != nil {
+		switch c := hc.cipher.(type) {
+		case cipher.Stream:
+			c.XORKeyStream(payload, payload)
+		case cipher.AEAD:
+			explicitIVLen = 8
+			if len(payload) < explicitIVLen {
+				return false, 0, alertBadRecordMAC
+			}
+			nonce := payload[:8]
+			payload = payload[8:]
+
+			var additionalData [13]byte
+			copy(additionalData[:], hc.seq[:])
+			copy(additionalData[8:], b.data[:3])
+			n := len(payload) - c.Overhead()
+			additionalData[11] = byte(n >> 8)
+			additionalData[12] = byte(n)
+			var err error
+			payload, err = c.Open(payload[:0], nonce, payload, additionalData[:])
+			if err != nil {
+				return false, 0, alertBadRecordMAC
+			}
+			b.resize(recordHeaderLen + explicitIVLen + len(payload))
+		case cbcMode:
+			blockSize := c.BlockSize()
+			if hc.version >= VersionTLS11 {
+				explicitIVLen = blockSize
+			}
+
+			if len(payload)%blockSize != 0 || len(payload) < roundUp(explicitIVLen+macSize+1, blockSize) {
+				return false, 0, alertBadRecordMAC
+			}
+
+			if explicitIVLen > 0 {
+				c.SetIV(payload[:explicitIVLen])
+				payload = payload[explicitIVLen:]
+			}
+			c.CryptBlocks(payload, payload)
+			if hc.version == VersionSSL30 {
+				payload, paddingGood = removePaddingSSL30(payload)
+			} else {
+				payload, paddingGood = removePadding(payload)
+			}
+			b.resize(recordHeaderLen + explicitIVLen + len(payload))
+
+			// note that we still have a timing side-channel in the
+			// MAC check, below. An attacker can align the record
+			// so that a correct padding will cause one less hash
+			// block to be calculated. Then they can iteratively
+			// decrypt a record by breaking each byte. See
+			// "Password Interception in a SSL/TLS Channel", Brice
+			// Canvel et al.
+			//
+			// However, our behavior matches OpenSSL, so we leak
+			// only as much as they do.
+		default:
+			panic("unknown cipher type")
+		}
+	}
+
+	// check, strip mac
+	if hc.mac != nil {
+		if len(payload) < macSize {
+			return false, 0, alertBadRecordMAC
+		}
+
+		// strip mac off payload, b.data
+		n := len(payload) - macSize
+		b.data[3] = byte(n >> 8)
+		b.data[4] = byte(n)
+		b.resize(recordHeaderLen + explicitIVLen + n)
+		remoteMAC := payload[n:]
+		localMAC := hc.mac.MAC(hc.inDigestBuf, hc.seq[0:], b.data[:recordHeaderLen], payload[:n])
+
+		if subtle.ConstantTimeCompare(localMAC, remoteMAC) != 1 || paddingGood != 255 {
+			return false, 0, alertBadRecordMAC
+		}
+		hc.inDigestBuf = localMAC
+	}
+	hc.incSeq()
+
+	return true, recordHeaderLen + explicitIVLen, 0
+}
+
+// padToBlockSize calculates the needed padding block, if any, for a payload.
+// On exit, prefix aliases payload and extends to the end of the last full
+// block of payload. finalBlock is a fresh slice which contains the contents of
+// any suffix of payload as well as the needed padding to make finalBlock a
+// full block.
+func padToBlockSize(payload []byte, blockSize int) (prefix, finalBlock []byte) {
+	overrun := len(payload) % blockSize
+	paddingLen := blockSize - overrun
+	prefix = payload[:len(payload)-overrun]
+	finalBlock = make([]byte, blockSize)
+	copy(finalBlock, payload[len(payload)-overrun:])
+	for i := overrun; i < blockSize; i++ {
+		finalBlock[i] = byte(paddingLen - 1)
+	}
+	return
+}
+
+// encrypt encrypts and macs the data in b.
+func (hc *halfConn) encrypt(b *block, explicitIVLen int) (bool, alert) {
+	// mac
+	if hc.mac != nil {
+		mac := hc.mac.MAC(hc.outDigestBuf, hc.seq[0:], b.data[:recordHeaderLen], b.data[recordHeaderLen+explicitIVLen:])
+
+		n := len(b.data)
+		b.resize(n + len(mac))
+		copy(b.data[n:], mac)
+		hc.outDigestBuf = mac
+	}
+
+	payload := b.data[recordHeaderLen:]
+
+	// encrypt
+	if hc.cipher != nil {
+		switch c := hc.cipher.(type) {
+		case cipher.Stream:
+			c.XORKeyStream(payload, payload)
+		case cipher.AEAD:
+			payloadLen := len(b.data) - recordHeaderLen - explicitIVLen
+			b.resize(len(b.data) + c.Overhead())
+			nonce := b.data[recordHeaderLen : recordHeaderLen+explicitIVLen]
+			payload := b.data[recordHeaderLen+explicitIVLen:]
+			payload = payload[:payloadLen]
+
+			var additionalData [13]byte
+			copy(additionalData[:], hc.seq[:])
+			copy(additionalData[8:], b.data[:3])
+			additionalData[11] = byte(payloadLen >> 8)
+			additionalData[12] = byte(payloadLen)
+
+			c.Seal(payload[:0], nonce, payload, additionalData[:])
+		case cbcMode:
+			blockSize := c.BlockSize()
+			if explicitIVLen > 0 {
+				c.SetIV(payload[:explicitIVLen])
+				payload = payload[explicitIVLen:]
+			}
+			prefix, finalBlock := padToBlockSize(payload, blockSize)
+			b.resize(recordHeaderLen + explicitIVLen + len(prefix) + len(finalBlock))
+			c.CryptBlocks(b.data[recordHeaderLen+explicitIVLen:], prefix)
+			c.CryptBlocks(b.data[recordHeaderLen+explicitIVLen+len(prefix):], finalBlock)
+		default:
+			panic("unknown cipher type")
+		}
+	}
+
+	// update length to include MAC and any block padding needed.
+	n := len(b.data) - recordHeaderLen
+	b.data[3] = byte(n >> 8)
+	b.data[4] = byte(n)
+	hc.incSeq()
+
+	return true, 0
+}
+
+// A block is a simple data buffer.
+type block struct {
+	data []byte
+	off  int // index for Read
+	link *block
+}
+
+// resize resizes block to be n bytes, growing if necessary.
+func (b *block) resize(n int) {
+	if n > cap(b.data) {
+		b.reserve(n)
+	}
+	b.data = b.data[0:n]
+}
+
+// reserve makes sure that block contains a capacity of at least n bytes.
+func (b *block) reserve(n int) {
+	if cap(b.data) >= n {
+		return
+	}
+	m := cap(b.data)
+	if m == 0 {
+		m = 1024
+	}
+	for m < n {
+		m *= 2
+	}
+	data := make([]byte, len(b.data), m)
+	copy(data, b.data)
+	b.data = data
+}
+
+// readFromUntil reads from r into b until b contains at least n bytes
+// or else returns an error.
+func (b *block) readFromUntil(r io.Reader, n int) error {
+	// quick case
+	if len(b.data) >= n {
+		return nil
+	}
+
+	// read until have enough.
+	b.reserve(n)
+	for {
+		m, err := r.Read(b.data[len(b.data):cap(b.data)])
+		b.data = b.data[0 : len(b.data)+m]
+		if len(b.data) >= n {
+			break
+		}
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (b *block) Read(p []byte) (n int, err error) {
+	n = copy(p, b.data[b.off:])
+	b.off += n
+	return
+}
+
+// newBlock allocates a new block, from hc's free list if possible.
+func (hc *halfConn) newBlock() *block {
+	b := hc.bfree
+	if b == nil {
+		return new(block)
+	}
+	hc.bfree = b.link
+	b.link = nil
+	b.resize(0)
+	return b
+}
+
+// freeBlock returns a block to hc's free list.
+// The protocol is such that each side only has a block or two on
+// its free list at a time, so there's no need to worry about
+// trimming the list, etc.
+func (hc *halfConn) freeBlock(b *block) {
+	b.link = hc.bfree
+	hc.bfree = b
+}
+
+// splitBlock splits a block after the first n bytes,
+// returning a block with those n bytes and a
+// block with the remainder.  the latter may be nil.
+func (hc *halfConn) splitBlock(b *block, n int) (*block, *block) {
+	if len(b.data) <= n {
+		return b, nil
+	}
+	bb := hc.newBlock()
+	bb.resize(len(b.data) - n)
+	copy(bb.data, b.data[n:])
+	b.data = b.data[0:n]
+	return b, bb
+}
+
+// readRecord reads the next TLS record from the connection
+// and updates the record layer state.
+// c.in.Mutex <= L; c.input == nil.
+func (c *Conn) readRecord(want recordType) error {
+	// Caller must be in sync with connection:
+	// handshake data if handshake not yet completed,
+	// else application data.  (We don't support renegotiation.)
+	switch want {
+	default:
+		return c.sendAlert(alertInternalError)
+	case recordTypeHandshake, recordTypeChangeCipherSpec:
+		if c.handshakeComplete {
+			return c.sendAlert(alertInternalError)
+		}
+	case recordTypeApplicationData:
+		if !c.handshakeComplete {
+			return c.sendAlert(alertInternalError)
+		}
+	}
+
+Again:
+	if c.rawInput == nil {
+		c.rawInput = c.in.newBlock()
+	}
+	b := c.rawInput
+
+	// Read header, payload.
+	if err := b.readFromUntil(c.conn, recordHeaderLen); err != nil {
+		// RFC suggests that EOF without an alertCloseNotify is
+		// an error, but popular web sites seem to do this,
+		// so we can't make it an error.
+		// if err == io.EOF {
+		// 	err = io.ErrUnexpectedEOF
+		// }
+		if e, ok := err.(net.Error); !ok || !e.Temporary() {
+			c.setError(err)
+		}
+		return err
+	}
+	typ := recordType(b.data[0])
+
+	// No valid TLS record has a type of 0x80, however SSLv2 handshakes
+	// start with a uint16 length where the MSB is set and the first record
+	// is always < 256 bytes long. Therefore typ == 0x80 strongly suggests
+	// an SSLv2 client.
+	if want == recordTypeHandshake && typ == 0x80 {
+		c.sendAlert(alertProtocolVersion)
+		return errors.New("tls: unsupported SSLv2 handshake received")
+	}
+
+	vers := uint16(b.data[1])<<8 | uint16(b.data[2])
+	n := int(b.data[3])<<8 | int(b.data[4])
+	if c.haveVers && vers != c.vers {
+		return c.sendAlert(alertProtocolVersion)
+	}
+	if n > maxCiphertext {
+		return c.sendAlert(alertRecordOverflow)
+	}
+	if !c.haveVers {
+		// First message, be extra suspicious:
+		// this might not be a TLS client.
+		// Bail out before reading a full 'body', if possible.
+		// The current max version is 3.1.
+		// If the version is >= 16.0, it's probably not real.
+		// Similarly, a clientHello message encodes in
+		// well under a kilobyte.  If the length is >= 12 kB,
+		// it's probably not real.
+		if (typ != recordTypeAlert && typ != want) || vers >= 0x1000 || n >= 0x3000 {
+			return c.sendAlert(alertUnexpectedMessage)
+		}
+	}
+	if err := b.readFromUntil(c.conn, recordHeaderLen+n); err != nil {
+		if err == io.EOF {
+			err = io.ErrUnexpectedEOF
+		}
+		if e, ok := err.(net.Error); !ok || !e.Temporary() {
+			c.setError(err)
+		}
+		return err
+	}
+
+	// Process message.
+	b, c.rawInput = c.in.splitBlock(b, recordHeaderLen+n)
+	ok, off, err := c.in.decrypt(b)
+	if !ok {
+		return c.sendAlert(err)
+	}
+	b.off = off
+	data := b.data[b.off:]
+	if len(data) > maxPlaintext {
+		c.sendAlert(alertRecordOverflow)
+		c.in.freeBlock(b)
+		return c.error()
+	}
+
+	switch typ {
+	default:
+		c.sendAlert(alertUnexpectedMessage)
+
+	case recordTypeAlert:
+		if len(data) != 2 {
+			c.sendAlert(alertUnexpectedMessage)
+			break
+		}
+		if alert(data[1]) == alertCloseNotify {
+			c.setError(io.EOF)
+			break
+		}
+		switch data[0] {
+		case alertLevelWarning:
+			// drop on the floor
+			c.in.freeBlock(b)
+			goto Again
+		case alertLevelError:
+			c.setError(&net.OpError{Op: "remote error", Err: alert(data[1])})
+		default:
+			c.sendAlert(alertUnexpectedMessage)
+		}
+
+	case recordTypeChangeCipherSpec:
+		if typ != want || len(data) != 1 || data[0] != 1 {
+			c.sendAlert(alertUnexpectedMessage)
+			break
+		}
+		err := c.in.changeCipherSpec()
+		if err != nil {
+			c.sendAlert(err.(alert))
+		}
+
+	case recordTypeApplicationData:
+		if typ != want {
+			c.sendAlert(alertUnexpectedMessage)
+			break
+		}
+		c.input = b
+		b = nil
+
+	case recordTypeHandshake:
+		// TODO(rsc): Should at least pick off connection close.
+		if typ != want && !c.isClient {
+			return c.sendAlert(alertNoRenegotiation)
+		}
+		c.hand.Write(data)
+	}
+
+	if b != nil {
+		c.in.freeBlock(b)
+	}
+	return c.error()
+}
+
+// sendAlert sends a TLS alert message.
+// c.out.Mutex <= L.
+func (c *Conn) sendAlertLocked(err alert) error {
+	switch err {
+	case alertNoRenegotiation, alertCloseNotify:
+		c.tmp[0] = alertLevelWarning
+	default:
+		c.tmp[0] = alertLevelError
+	}
+	c.tmp[1] = byte(err)
+	c.writeRecord(recordTypeAlert, c.tmp[0:2])
+	// closeNotify is a special case in that it isn't an error:
+	if err != alertCloseNotify {
+		return c.setError(&net.OpError{Op: "local error", Err: err})
+	}
+	return nil
+}
+
+// sendAlert sends a TLS alert message.
+// L < c.out.Mutex.
+func (c *Conn) sendAlert(err alert) error {
+	c.out.Lock()
+	defer c.out.Unlock()
+	return c.sendAlertLocked(err)
+}
+
+// writeRecord writes a TLS record with the given type and payload
+// to the connection and updates the record layer state.
+// c.out.Mutex <= L.
+func (c *Conn) writeRecord(typ recordType, data []byte) (n int, err error) {
+	b := c.out.newBlock()
+	for len(data) > 0 {
+		m := len(data)
+		if m > maxPlaintext {
+			m = maxPlaintext
+		}
+		explicitIVLen := 0
+		explicitIVIsSeq := false
+
+		var cbc cbcMode
+		if c.out.version >= VersionTLS11 {
+			var ok bool
+			if cbc, ok = c.out.cipher.(cbcMode); ok {
+				explicitIVLen = cbc.BlockSize()
+			}
+		}
+		if explicitIVLen == 0 {
+			if _, ok := c.out.cipher.(cipher.AEAD); ok {
+				explicitIVLen = 8
+				// The AES-GCM construction in TLS has an
+				// explicit nonce so that the nonce can be
+				// random. However, the nonce is only 8 bytes
+				// which is too small for a secure, random
+				// nonce. Therefore we use the sequence number
+				// as the nonce.
+				explicitIVIsSeq = true
+			}
+		}
+		b.resize(recordHeaderLen + explicitIVLen + m)
+		b.data[0] = byte(typ)
+		vers := c.vers
+		if vers == 0 {
+			// Some TLS servers fail if the record version is
+			// greater than TLS 1.0 for the initial ClientHello.
+			vers = VersionTLS10
+		}
+		b.data[1] = byte(vers >> 8)
+		b.data[2] = byte(vers)
+		b.data[3] = byte(m >> 8)
+		b.data[4] = byte(m)
+		if explicitIVLen > 0 {
+			explicitIV := b.data[recordHeaderLen : recordHeaderLen+explicitIVLen]
+			if explicitIVIsSeq {
+				copy(explicitIV, c.out.seq[:])
+			} else {
+				if _, err = io.ReadFull(c.config.rand(), explicitIV); err != nil {
+					break
+				}
+			}
+		}
+		copy(b.data[recordHeaderLen+explicitIVLen:], data)
+		c.out.encrypt(b, explicitIVLen)
+		_, err = c.conn.Write(b.data)
+		if err != nil {
+			break
+		}
+		n += m
+		data = data[m:]
+	}
+	c.out.freeBlock(b)
+
+	if typ == recordTypeChangeCipherSpec {
+		err = c.out.changeCipherSpec()
+		if err != nil {
+			// Cannot call sendAlert directly,
+			// because we already hold c.out.Mutex.
+			c.tmp[0] = alertLevelError
+			c.tmp[1] = byte(err.(alert))
+			c.writeRecord(recordTypeAlert, c.tmp[0:2])
+			return n, c.setError(&net.OpError{Op: "local error", Err: err})
+		}
+	}
+	return
+}
+
+// readHandshake reads the next handshake message from
+// the record layer.
+// c.in.Mutex < L; c.out.Mutex < L.
+func (c *Conn) readHandshake() (interface{}, error) {
+	for c.hand.Len() < 4 {
+		if err := c.error(); err != nil {
+			return nil, err
+		}
+		if err := c.readRecord(recordTypeHandshake); err != nil {
+			return nil, err
+		}
+	}
+
+	data := c.hand.Bytes()
+	n := int(data[1])<<16 | int(data[2])<<8 | int(data[3])
+	if n > maxHandshake {
+		c.sendAlert(alertInternalError)
+		return nil, c.error()
+	}
+	for c.hand.Len() < 4+n {
+		if err := c.error(); err != nil {
+			return nil, err
+		}
+		if err := c.readRecord(recordTypeHandshake); err != nil {
+			return nil, err
+		}
+	}
+	data = c.hand.Next(4 + n)
+	var m handshakeMessage
+	switch data[0] {
+	case typeHelloRequest:
+		m = new(helloRequestMsg)
+	case typeClientHello:
+		m = new(clientHelloMsg)
+	case typeServerHello:
+		m = new(serverHelloMsg)
+	case typeCertificate:
+		m = new(certificateMsg)
+	case typeCertificateRequest:
+		m = &certificateRequestMsg{
+			hasSignatureAndHash: c.vers >= VersionTLS12,
+		}
+	case typeCertificateStatus:
+		m = new(certificateStatusMsg)
+	case typeServerKeyExchange:
+		m = new(serverKeyExchangeMsg)
+	case typeServerHelloDone:
+		m = new(serverHelloDoneMsg)
+	case typeClientKeyExchange:
+		m = new(clientKeyExchangeMsg)
+	case typeCertificateVerify:
+		m = &certificateVerifyMsg{
+			hasSignatureAndHash: c.vers >= VersionTLS12,
+		}
+	case typeNextProtocol:
+		m = new(nextProtoMsg)
+	case typeFinished:
+		m = new(finishedMsg)
+	default:
+		c.sendAlert(alertUnexpectedMessage)
+		return nil, alertUnexpectedMessage
+	}
+
+	// The handshake message unmarshallers
+	// expect to be able to keep references to data,
+	// so pass in a fresh copy that won't be overwritten.
+	data = append([]byte(nil), data...)
+
+	if !m.unmarshal(data) {
+		c.sendAlert(alertUnexpectedMessage)
+		return nil, alertUnexpectedMessage
+	}
+	return m, nil
+}
+
+// Write writes data to the connection.
+func (c *Conn) Write(b []byte) (int, error) {
+	if err := c.error(); err != nil {
+		return 0, err
+	}
+
+	if err := c.Handshake(); err != nil {
+		return 0, c.setError(err)
+	}
+
+	c.out.Lock()
+	defer c.out.Unlock()
+
+	if !c.handshakeComplete {
+		return 0, alertInternalError
+	}
+
+	// SSL 3.0 and TLS 1.0 are susceptible to a chosen-plaintext
+	// attack when using block mode ciphers due to predictable IVs.
+	// This can be prevented by splitting each Application Data
+	// record into two records, effectively randomizing the IV.
+	//
+	// http://www.openssl.org/~bodo/tls-cbc.txt
+	// https://bugzilla.mozilla.org/show_bug.cgi?id=665814
+	// http://www.imperialviolet.org/2012/01/15/beastfollowup.html
+
+	var m int
+	if len(b) > 1 && c.vers <= VersionTLS10 {
+		if _, ok := c.out.cipher.(cipher.BlockMode); ok {
+			n, err := c.writeRecord(recordTypeApplicationData, b[:1])
+			if err != nil {
+				return n, c.setError(err)
+			}
+			m, b = 1, b[1:]
+		}
+	}
+
+	n, err := c.writeRecord(recordTypeApplicationData, b)
+	return n + m, c.setError(err)
+}
+
+func (c *Conn) handleRenegotiation() error {
+	c.handshakeComplete = false
+	if !c.isClient {
+		panic("renegotiation should only happen for a client")
+	}
+
+	msg, err := c.readHandshake()
+	if err != nil {
+		return err
+	}
+	_, ok := msg.(*helloRequestMsg)
+	if !ok {
+		c.sendAlert(alertUnexpectedMessage)
+		return alertUnexpectedMessage
+	}
+
+	return c.Handshake()
+}
+
+// Read can be made to time out and return a net.Error with Timeout() == true
+// after a fixed time limit; see SetDeadline and SetReadDeadline.
+func (c *Conn) Read(b []byte) (n int, err error) {
+	if err = c.Handshake(); err != nil {
+		return
+	}
+
+	c.in.Lock()
+	defer c.in.Unlock()
+
+	// Some OpenSSL servers send empty records in order to randomize the
+	// CBC IV. So this loop ignores a limited number of empty records.
+	const maxConsecutiveEmptyRecords = 100
+	for emptyRecordCount := 0; emptyRecordCount <= maxConsecutiveEmptyRecords; emptyRecordCount++ {
+		for c.input == nil && c.error() == nil {
+			if err := c.readRecord(recordTypeApplicationData); err != nil {
+				// Soft error, like EAGAIN
+				return 0, err
+			}
+			if c.hand.Len() > 0 {
+				// We received handshake bytes, indicating the start of
+				// a renegotiation.
+				if err := c.handleRenegotiation(); err != nil {
+					return 0, err
+				}
+				continue
+			}
+		}
+		if err := c.error(); err != nil {
+			return 0, err
+		}
+
+		n, err = c.input.Read(b)
+		if c.input.off >= len(c.input.data) {
+			c.in.freeBlock(c.input)
+			c.input = nil
+		}
+
+		if n != 0 || err != nil {
+			return n, err
+		}
+	}
+
+	return 0, io.ErrNoProgress
+}
+
+// Close closes the connection.
+func (c *Conn) Close() error {
+	var alertErr error
+
+	c.handshakeMutex.Lock()
+	defer c.handshakeMutex.Unlock()
+	if c.handshakeComplete {
+		alertErr = c.sendAlert(alertCloseNotify)
+	}
+
+	if err := c.conn.Close(); err != nil {
+		return err
+	}
+	return alertErr
+}
+
+// Handshake runs the client or server handshake
+// protocol if it has not yet been run.
+// Most uses of this package need not call Handshake
+// explicitly: the first Read or Write will call it automatically.
+func (c *Conn) Handshake() error {
+	c.handshakeMutex.Lock()
+	defer c.handshakeMutex.Unlock()
+	if err := c.error(); err != nil {
+		return err
+	}
+	if c.handshakeComplete {
+		return nil
+	}
+	if c.isClient {
+		return c.clientHandshake()
+	}
+	return c.serverHandshake()
+}
+
+// ConnectionState returns basic TLS details about the connection.
+func (c *Conn) ConnectionState() ConnectionState {
+	c.handshakeMutex.Lock()
+	defer c.handshakeMutex.Unlock()
+
+	var state ConnectionState
+	state.HandshakeComplete = c.handshakeComplete
+	if c.handshakeComplete {
+		state.NegotiatedProtocol = c.clientProtocol
+		state.DidResume = c.didResume
+		state.NegotiatedProtocolIsMutual = !c.clientProtocolFallback
+		state.CipherSuite = c.cipherSuite
+		state.PeerCertificates = c.peerCertificates
+		state.VerifiedChains = c.verifiedChains
+		state.ServerName = c.serverName
+	}
+
+	return state
+}
+
+// OCSPResponse returns the stapled OCSP response from the TLS server, if
+// any. (Only valid for client connections.)
+func (c *Conn) OCSPResponse() []byte {
+	c.handshakeMutex.Lock()
+	defer c.handshakeMutex.Unlock()
+
+	return c.ocspResponse
+}
+
+// VerifyHostname checks that the peer certificate chain is valid for
+// connecting to host.  If so, it returns nil; if not, it returns an error
+// describing the problem.
+func (c *Conn) VerifyHostname(host string) error {
+	c.handshakeMutex.Lock()
+	defer c.handshakeMutex.Unlock()
+	if !c.isClient {
+		return errors.New("VerifyHostname called on TLS server connection")
+	}
+	if !c.handshakeComplete {
+		return errors.New("TLS handshake has not yet been performed")
+	}
+	return c.peerCertificates[0].VerifyHostname(host)
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/generate_cert.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/generate_cert.go
new file mode 100644
index 000000000..b417ea464
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/generate_cert.go
@@ -0,0 +1,118 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build ignore
+
+// Generate a self-signed X.509 certificate for a TLS server. Outputs to
+// 'cert.pem' and 'key.pem' and will overwrite existing files.
+
+package main
+
+import (
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"encoding/pem"
+	"flag"
+	"fmt"
+	"log"
+	"math/big"
+	"net"
+	"os"
+	"strings"
+	"time"
+)
+
+var (
+	host      = flag.String("host", "", "Comma-separated hostnames and IPs to generate a certificate for")
+	validFrom = flag.String("start-date", "", "Creation date formatted as Jan 1 15:04:05 2011")
+	validFor  = flag.Duration("duration", 365*24*time.Hour, "Duration that certificate is valid for")
+	isCA      = flag.Bool("ca", false, "whether this cert should be its own Certificate Authority")
+	rsaBits   = flag.Int("rsa-bits", 2048, "Size of RSA key to generate")
+)
+
+func main() {
+	flag.Parse()
+
+	if len(*host) == 0 {
+		log.Fatalf("Missing required --host parameter")
+	}
+
+	priv, err := rsa.GenerateKey(rand.Reader, *rsaBits)
+	if err != nil {
+		log.Fatalf("failed to generate private key: %s", err)
+		return
+	}
+
+	var notBefore time.Time
+	if len(*validFrom) == 0 {
+		notBefore = time.Now()
+	} else {
+		notBefore, err = time.Parse("Jan 2 15:04:05 2006", *validFrom)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Failed to parse creation date: %s\n", err)
+			os.Exit(1)
+		}
+	}
+
+	notAfter := notBefore.Add(*validFor)
+
+	// end of ASN.1 time
+	endOfTime := time.Date(2049, 12, 31, 23, 59, 59, 0, time.UTC)
+	if notAfter.After(endOfTime) {
+		notAfter = endOfTime
+	}
+
+	template := x509.Certificate{
+		SerialNumber: new(big.Int).SetInt64(0),
+		Subject: pkix.Name{
+			Organization: []string{"Acme Co"},
+		},
+		NotBefore: notBefore,
+		NotAfter:  notAfter,
+
+		KeyUsage:              x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
+		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
+		BasicConstraintsValid: true,
+	}
+
+	hosts := strings.Split(*host, ",")
+	for _, h := range hosts {
+		if ip := net.ParseIP(h); ip != nil {
+			template.IPAddresses = append(template.IPAddresses, ip)
+		} else {
+			template.DNSNames = append(template.DNSNames, h)
+		}
+	}
+
+	if *isCA {
+		template.IsCA = true
+		template.KeyUsage |= x509.KeyUsageCertSign
+	}
+
+	derBytes, err := x509.CreateCertificate(rand.Reader, &template, &template, &priv.PublicKey, priv)
+	if err != nil {
+		log.Fatalf("Failed to create certificate: %s", err)
+		return
+	}
+
+	certOut, err := os.Create("cert.pem")
+	if err != nil {
+		log.Fatalf("failed to open cert.pem for writing: %s", err)
+		return
+	}
+	pem.Encode(certOut, &pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
+	certOut.Close()
+	log.Print("written cert.pem\n")
+
+	keyOut, err := os.OpenFile("key.pem", os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
+	if err != nil {
+		log.Print("failed to open key.pem for writing:", err)
+		return
+	}
+	pem.Encode(keyOut, &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(priv)})
+	keyOut.Close()
+	log.Print("written key.pem\n")
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/handshake_client.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/handshake_client.go
new file mode 100644
index 000000000..85e4adefc
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/handshake_client.go
@@ -0,0 +1,411 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package tls
+
+import (
+	"bytes"
+	"crypto/ecdsa"
+	"crypto/rsa"
+	"crypto/subtle"
+	"crypto/x509"
+	"encoding/asn1"
+	"errors"
+	"io"
+	"strconv"
+)
+
+func (c *Conn) clientHandshake() error {
+	if c.config == nil {
+		c.config = defaultConfig()
+	}
+
+	hello := &clientHelloMsg{
+		vers:               c.config.maxVersion(),
+		compressionMethods: []uint8{compressionNone},
+		random:             make([]byte, 32),
+		ocspStapling:       true,
+		serverName:         c.config.ServerName,
+		supportedCurves:    []uint16{curveP256, curveP384, curveP521},
+		supportedPoints:    []uint8{pointFormatUncompressed},
+		nextProtoNeg:       len(c.config.NextProtos) > 0,
+	}
+
+	possibleCipherSuites := c.config.cipherSuites()
+	hello.cipherSuites = make([]uint16, 0, len(possibleCipherSuites))
+
+NextCipherSuite:
+	for _, suiteId := range possibleCipherSuites {
+		for _, suite := range cipherSuites {
+			if suite.id != suiteId {
+				continue
+			}
+			// Don't advertise TLS 1.2-only cipher suites unless
+			// we're attempting TLS 1.2.
+			if hello.vers < VersionTLS12 && suite.flags&suiteTLS12 != 0 {
+				continue
+			}
+			hello.cipherSuites = append(hello.cipherSuites, suiteId)
+			continue NextCipherSuite
+		}
+	}
+
+	t := uint32(c.config.time().Unix())
+	hello.random[0] = byte(t >> 24)
+	hello.random[1] = byte(t >> 16)
+	hello.random[2] = byte(t >> 8)
+	hello.random[3] = byte(t)
+	_, err := io.ReadFull(c.config.rand(), hello.random[4:])
+	if err != nil {
+		c.sendAlert(alertInternalError)
+		return errors.New("short read from Rand")
+	}
+
+	if hello.vers >= VersionTLS12 {
+		hello.signatureAndHashes = supportedSKXSignatureAlgorithms
+	}
+
+	c.writeRecord(recordTypeHandshake, hello.marshal())
+
+	msg, err := c.readHandshake()
+	if err != nil {
+		return err
+	}
+	serverHello, ok := msg.(*serverHelloMsg)
+	if !ok {
+		return c.sendAlert(alertUnexpectedMessage)
+	}
+
+	vers, ok := c.config.mutualVersion(serverHello.vers)
+	if !ok || vers < VersionTLS10 {
+		// TLS 1.0 is the minimum version supported as a client.
+		return c.sendAlert(alertProtocolVersion)
+	}
+	c.vers = vers
+	c.haveVers = true
+
+	finishedHash := newFinishedHash(c.vers)
+	finishedHash.Write(hello.marshal())
+	finishedHash.Write(serverHello.marshal())
+
+	if serverHello.compressionMethod != compressionNone {
+		return c.sendAlert(alertUnexpectedMessage)
+	}
+
+	if !hello.nextProtoNeg && serverHello.nextProtoNeg {
+		c.sendAlert(alertHandshakeFailure)
+		return errors.New("server advertised unrequested NPN")
+	}
+
+	suite := mutualCipherSuite(c.config.cipherSuites(), serverHello.cipherSuite)
+	if suite == nil {
+		return c.sendAlert(alertHandshakeFailure)
+	}
+
+	msg, err = c.readHandshake()
+	if err != nil {
+		return err
+	}
+	certMsg, ok := msg.(*certificateMsg)
+	if !ok || len(certMsg.certificates) == 0 {
+		return c.sendAlert(alertUnexpectedMessage)
+	}
+	finishedHash.Write(certMsg.marshal())
+
+	certs := make([]*x509.Certificate, len(certMsg.certificates))
+	for i, asn1Data := range certMsg.certificates {
+		cert, err := x509.ParseCertificate(asn1Data)
+		if err != nil {
+			c.sendAlert(alertBadCertificate)
+			return errors.New("failed to parse certificate from server: " + err.Error())
+		}
+		certs[i] = cert
+	}
+
+	if !c.config.InsecureSkipVerify {
+		opts := x509.VerifyOptions{
+			Roots:         c.config.RootCAs,
+			CurrentTime:   c.config.time(),
+			DNSName:       c.config.ServerName,
+			Intermediates: x509.NewCertPool(),
+		}
+
+		for i, cert := range certs {
+			if i == 0 {
+				continue
+			}
+			opts.Intermediates.AddCert(cert)
+		}
+		c.verifiedChains, err = certs[0].Verify(opts)
+		if err != nil {
+			c.sendAlert(alertBadCertificate)
+			return err
+		}
+	}
+
+	switch certs[0].PublicKey.(type) {
+	case *rsa.PublicKey, *ecdsa.PublicKey:
+		break
+	default:
+		return c.sendAlert(alertUnsupportedCertificate)
+	}
+
+	c.peerCertificates = certs
+
+	if serverHello.ocspStapling {
+		msg, err = c.readHandshake()
+		if err != nil {
+			return err
+		}
+		cs, ok := msg.(*certificateStatusMsg)
+		if !ok {
+			return c.sendAlert(alertUnexpectedMessage)
+		}
+		finishedHash.Write(cs.marshal())
+
+		if cs.statusType == statusTypeOCSP {
+			c.ocspResponse = cs.response
+		}
+	}
+
+	msg, err = c.readHandshake()
+	if err != nil {
+		return err
+	}
+
+	keyAgreement := suite.ka(c.vers)
+
+	skx, ok := msg.(*serverKeyExchangeMsg)
+	if ok {
+		finishedHash.Write(skx.marshal())
+		err = keyAgreement.processServerKeyExchange(c.config, hello, serverHello, certs[0], skx)
+		if err != nil {
+			c.sendAlert(alertUnexpectedMessage)
+			return err
+		}
+
+		msg, err = c.readHandshake()
+		if err != nil {
+			return err
+		}
+	}
+
+	var chainToSend *Certificate
+	var certRequested bool
+	certReq, ok := msg.(*certificateRequestMsg)
+	if ok {
+		certRequested = true
+
+		// RFC 4346 on the certificateAuthorities field:
+		// A list of the distinguished names of acceptable certificate
+		// authorities. These distinguished names may specify a desired
+		// distinguished name for a root CA or for a subordinate CA;
+		// thus, this message can be used to describe both known roots
+		// and a desired authorization space. If the
+		// certificate_authorities list is empty then the client MAY
+		// send any certificate of the appropriate
+		// ClientCertificateType, unless there is some external
+		// arrangement to the contrary.
+
+		finishedHash.Write(certReq.marshal())
+
+		var rsaAvail, ecdsaAvail bool
+		for _, certType := range certReq.certificateTypes {
+			switch certType {
+			case certTypeRSASign:
+				rsaAvail = true
+			case certTypeECDSASign:
+				ecdsaAvail = true
+			}
+		}
+
+		// We need to search our list of client certs for one
+		// where SignatureAlgorithm is RSA and the Issuer is in
+		// certReq.certificateAuthorities
+	findCert:
+		for i, chain := range c.config.Certificates {
+			if !rsaAvail && !ecdsaAvail {
+				continue
+			}
+
+			for j, cert := range chain.Certificate {
+				x509Cert := chain.Leaf
+				// parse the certificate if this isn't the leaf
+				// node, or if chain.Leaf was nil
+				if j != 0 || x509Cert == nil {
+					if x509Cert, err = x509.ParseCertificate(cert); err != nil {
+						c.sendAlert(alertInternalError)
+						return errors.New("tls: failed to parse client certificate #" + strconv.Itoa(i) + ": " + err.Error())
+					}
+				}
+
+				switch {
+				case rsaAvail && x509Cert.PublicKeyAlgorithm == x509.RSA:
+				case ecdsaAvail && x509Cert.PublicKeyAlgorithm == x509.ECDSA:
+				default:
+					continue findCert
+				}
+
+				if len(certReq.certificateAuthorities) == 0 {
+					// they gave us an empty list, so just take the
+					// first RSA cert from c.config.Certificates
+					chainToSend = &chain
+					break findCert
+				}
+
+				for _, ca := range certReq.certificateAuthorities {
+					if bytes.Equal(x509Cert.RawIssuer, ca) {
+						chainToSend = &chain
+						break findCert
+					}
+				}
+			}
+		}
+
+		msg, err = c.readHandshake()
+		if err != nil {
+			return err
+		}
+	}
+
+	shd, ok := msg.(*serverHelloDoneMsg)
+	if !ok {
+		return c.sendAlert(alertUnexpectedMessage)
+	}
+	finishedHash.Write(shd.marshal())
+
+	// If the server requested a certificate then we have to send a
+	// Certificate message, even if it's empty because we don't have a
+	// certificate to send.
+	if certRequested {
+		certMsg = new(certificateMsg)
+		if chainToSend != nil {
+			certMsg.certificates = chainToSend.Certificate
+		}
+		finishedHash.Write(certMsg.marshal())
+		c.writeRecord(recordTypeHandshake, certMsg.marshal())
+	}
+
+	preMasterSecret, ckx, err := keyAgreement.generateClientKeyExchange(c.config, hello, certs[0])
+	if err != nil {
+		c.sendAlert(alertInternalError)
+		return err
+	}
+	if ckx != nil {
+		finishedHash.Write(ckx.marshal())
+		c.writeRecord(recordTypeHandshake, ckx.marshal())
+	}
+
+	if chainToSend != nil {
+		var signed []byte
+		certVerify := &certificateVerifyMsg{
+			hasSignatureAndHash: c.vers >= VersionTLS12,
+		}
+
+		switch key := c.config.Certificates[0].PrivateKey.(type) {
+		case *ecdsa.PrivateKey:
+			digest, _, hashId := finishedHash.hashForClientCertificate(signatureECDSA)
+			r, s, err := ecdsa.Sign(c.config.rand(), key, digest)
+			if err == nil {
+				signed, err = asn1.Marshal(ecdsaSignature{r, s})
+			}
+			certVerify.signatureAndHash.signature = signatureECDSA
+			certVerify.signatureAndHash.hash = hashId
+		case *rsa.PrivateKey:
+			digest, hashFunc, hashId := finishedHash.hashForClientCertificate(signatureRSA)
+			signed, err = rsa.SignPKCS1v15(c.config.rand(), key, hashFunc, digest)
+			certVerify.signatureAndHash.signature = signatureRSA
+			certVerify.signatureAndHash.hash = hashId
+		default:
+			err = errors.New("unknown private key type")
+		}
+		if err != nil {
+			return c.sendAlert(alertInternalError)
+		}
+		certVerify.signature = signed
+
+		finishedHash.Write(certVerify.marshal())
+		c.writeRecord(recordTypeHandshake, certVerify.marshal())
+	}
+
+	masterSecret := masterFromPreMasterSecret(c.vers, preMasterSecret, hello.random, serverHello.random)
+	clientMAC, serverMAC, clientKey, serverKey, clientIV, serverIV :=
+		keysFromMasterSecret(c.vers, masterSecret, hello.random, serverHello.random, suite.macLen, suite.keyLen, suite.ivLen)
+
+	var clientCipher interface{}
+	var clientHash macFunction
+	if suite.cipher != nil {
+		clientCipher = suite.cipher(clientKey, clientIV, false /* not for reading */)
+		clientHash = suite.mac(c.vers, clientMAC)
+	} else {
+		clientCipher = suite.aead(clientKey, clientIV)
+	}
+	c.out.prepareCipherSpec(c.vers, clientCipher, clientHash)
+	c.writeRecord(recordTypeChangeCipherSpec, []byte{1})
+
+	if serverHello.nextProtoNeg {
+		nextProto := new(nextProtoMsg)
+		proto, fallback := mutualProtocol(c.config.NextProtos, serverHello.nextProtos)
+		nextProto.proto = proto
+		c.clientProtocol = proto
+		c.clientProtocolFallback = fallback
+
+		finishedHash.Write(nextProto.marshal())
+		c.writeRecord(recordTypeHandshake, nextProto.marshal())
+	}
+
+	finished := new(finishedMsg)
+	finished.verifyData = finishedHash.clientSum(masterSecret)
+	finishedHash.Write(finished.marshal())
+	c.writeRecord(recordTypeHandshake, finished.marshal())
+
+	var serverCipher interface{}
+	var serverHash macFunction
+	if suite.cipher != nil {
+		serverCipher = suite.cipher(serverKey, serverIV, true /* for reading */)
+		serverHash = suite.mac(c.vers, serverMAC)
+	} else {
+		serverCipher = suite.aead(serverKey, serverIV)
+	}
+	c.in.prepareCipherSpec(c.vers, serverCipher, serverHash)
+	c.readRecord(recordTypeChangeCipherSpec)
+	if err := c.error(); err != nil {
+		return err
+	}
+
+	msg, err = c.readHandshake()
+	if err != nil {
+		return err
+	}
+	serverFinished, ok := msg.(*finishedMsg)
+	if !ok {
+		return c.sendAlert(alertUnexpectedMessage)
+	}
+
+	verify := finishedHash.serverSum(masterSecret)
+	if len(verify) != len(serverFinished.verifyData) ||
+		subtle.ConstantTimeCompare(verify, serverFinished.verifyData) != 1 {
+		return c.sendAlert(alertHandshakeFailure)
+	}
+
+	c.handshakeComplete = true
+	c.cipherSuite = suite.id
+	return nil
+}
+
+// mutualProtocol finds the mutual Next Protocol Negotiation protocol given the
+// set of client and server supported protocols. The set of client supported
+// protocols must not be empty. It returns the resulting protocol and flag
+// indicating if the fallback case was reached.
+func mutualProtocol(clientProtos, serverProtos []string) (string, bool) {
+	for _, s := range serverProtos {
+		for _, c := range clientProtos {
+			if s == c {
+				return s, false
+			}
+		}
+	}
+
+	return clientProtos[0], true
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/handshake_messages.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/handshake_messages.go
new file mode 100644
index 000000000..8197391e3
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/handshake_messages.go
@@ -0,0 +1,1304 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package tls
+
+import "bytes"
+
+type clientHelloMsg struct {
+	raw                []byte
+	vers               uint16
+	random             []byte
+	sessionId          []byte
+	cipherSuites       []uint16
+	compressionMethods []uint8
+	nextProtoNeg       bool
+	serverName         string
+	ocspStapling       bool
+	supportedCurves    []uint16
+	supportedPoints    []uint8
+	ticketSupported    bool
+	sessionTicket      []uint8
+	signatureAndHashes []signatureAndHash
+}
+
+func (m *clientHelloMsg) equal(i interface{}) bool {
+	m1, ok := i.(*clientHelloMsg)
+	if !ok {
+		return false
+	}
+
+	return bytes.Equal(m.raw, m1.raw) &&
+		m.vers == m1.vers &&
+		bytes.Equal(m.random, m1.random) &&
+		bytes.Equal(m.sessionId, m1.sessionId) &&
+		eqUint16s(m.cipherSuites, m1.cipherSuites) &&
+		bytes.Equal(m.compressionMethods, m1.compressionMethods) &&
+		m.nextProtoNeg == m1.nextProtoNeg &&
+		m.serverName == m1.serverName &&
+		m.ocspStapling == m1.ocspStapling &&
+		eqUint16s(m.supportedCurves, m1.supportedCurves) &&
+		bytes.Equal(m.supportedPoints, m1.supportedPoints) &&
+		m.ticketSupported == m1.ticketSupported &&
+		bytes.Equal(m.sessionTicket, m1.sessionTicket) &&
+		eqSignatureAndHashes(m.signatureAndHashes, m1.signatureAndHashes)
+}
+
+func (m *clientHelloMsg) marshal() []byte {
+	if m.raw != nil {
+		return m.raw
+	}
+
+	length := 2 + 32 + 1 + len(m.sessionId) + 2 + len(m.cipherSuites)*2 + 1 + len(m.compressionMethods)
+	numExtensions := 0
+	extensionsLength := 0
+	if m.nextProtoNeg {
+		numExtensions++
+	}
+	if m.ocspStapling {
+		extensionsLength += 1 + 2 + 2
+		numExtensions++
+	}
+	if len(m.serverName) > 0 {
+		extensionsLength += 5 + len(m.serverName)
+		numExtensions++
+	}
+	if len(m.supportedCurves) > 0 {
+		extensionsLength += 2 + 2*len(m.supportedCurves)
+		numExtensions++
+	}
+	if len(m.supportedPoints) > 0 {
+		extensionsLength += 1 + len(m.supportedPoints)
+		numExtensions++
+	}
+	if m.ticketSupported {
+		extensionsLength += len(m.sessionTicket)
+		numExtensions++
+	}
+	if len(m.signatureAndHashes) > 0 {
+		extensionsLength += 2 + 2*len(m.signatureAndHashes)
+		numExtensions++
+	}
+	if numExtensions > 0 {
+		extensionsLength += 4 * numExtensions
+		length += 2 + extensionsLength
+	}
+
+	x := make([]byte, 4+length)
+	x[0] = typeClientHello
+	x[1] = uint8(length >> 16)
+	x[2] = uint8(length >> 8)
+	x[3] = uint8(length)
+	x[4] = uint8(m.vers >> 8)
+	x[5] = uint8(m.vers)
+	copy(x[6:38], m.random)
+	x[38] = uint8(len(m.sessionId))
+	copy(x[39:39+len(m.sessionId)], m.sessionId)
+	y := x[39+len(m.sessionId):]
+	y[0] = uint8(len(m.cipherSuites) >> 7)
+	y[1] = uint8(len(m.cipherSuites) << 1)
+	for i, suite := range m.cipherSuites {
+		y[2+i*2] = uint8(suite >> 8)
+		y[3+i*2] = uint8(suite)
+	}
+	z := y[2+len(m.cipherSuites)*2:]
+	z[0] = uint8(len(m.compressionMethods))
+	copy(z[1:], m.compressionMethods)
+
+	z = z[1+len(m.compressionMethods):]
+	if numExtensions > 0 {
+		z[0] = byte(extensionsLength >> 8)
+		z[1] = byte(extensionsLength)
+		z = z[2:]
+	}
+	if m.nextProtoNeg {
+		z[0] = byte(extensionNextProtoNeg >> 8)
+		z[1] = byte(extensionNextProtoNeg)
+		// The length is always 0
+		z = z[4:]
+	}
+	if len(m.serverName) > 0 {
+		z[0] = byte(extensionServerName >> 8)
+		z[1] = byte(extensionServerName)
+		l := len(m.serverName) + 5
+		z[2] = byte(l >> 8)
+		z[3] = byte(l)
+		z = z[4:]
+
+		// RFC 3546, section 3.1
+		//
+		// struct {
+		//     NameType name_type;
+		//     select (name_type) {
+		//         case host_name: HostName;
+		//     } name;
+		// } ServerName;
+		//
+		// enum {
+		//     host_name(0), (255)
+		// } NameType;
+		//
+		// opaque HostName<1..2^16-1>;
+		//
+		// struct {
+		//     ServerName server_name_list<1..2^16-1>
+		// } ServerNameList;
+
+		z[0] = byte((len(m.serverName) + 3) >> 8)
+		z[1] = byte(len(m.serverName) + 3)
+		z[3] = byte(len(m.serverName) >> 8)
+		z[4] = byte(len(m.serverName))
+		copy(z[5:], []byte(m.serverName))
+		z = z[l:]
+	}
+	if m.ocspStapling {
+		// RFC 4366, section 3.6
+		z[0] = byte(extensionStatusRequest >> 8)
+		z[1] = byte(extensionStatusRequest)
+		z[2] = 0
+		z[3] = 5
+		z[4] = 1 // OCSP type
+		// Two zero valued uint16s for the two lengths.
+		z = z[9:]
+	}
+	if len(m.supportedCurves) > 0 {
+		// http://tools.ietf.org/html/rfc4492#section-5.5.1
+		z[0] = byte(extensionSupportedCurves >> 8)
+		z[1] = byte(extensionSupportedCurves)
+		l := 2 + 2*len(m.supportedCurves)
+		z[2] = byte(l >> 8)
+		z[3] = byte(l)
+		l -= 2
+		z[4] = byte(l >> 8)
+		z[5] = byte(l)
+		z = z[6:]
+		for _, curve := range m.supportedCurves {
+			z[0] = byte(curve >> 8)
+			z[1] = byte(curve)
+			z = z[2:]
+		}
+	}
+	if len(m.supportedPoints) > 0 {
+		// http://tools.ietf.org/html/rfc4492#section-5.5.2
+		z[0] = byte(extensionSupportedPoints >> 8)
+		z[1] = byte(extensionSupportedPoints)
+		l := 1 + len(m.supportedPoints)
+		z[2] = byte(l >> 8)
+		z[3] = byte(l)
+		l--
+		z[4] = byte(l)
+		z = z[5:]
+		for _, pointFormat := range m.supportedPoints {
+			z[0] = byte(pointFormat)
+			z = z[1:]
+		}
+	}
+	if m.ticketSupported {
+		// http://tools.ietf.org/html/rfc5077#section-3.2
+		z[0] = byte(extensionSessionTicket >> 8)
+		z[1] = byte(extensionSessionTicket)
+		l := len(m.sessionTicket)
+		z[2] = byte(l >> 8)
+		z[3] = byte(l)
+		z = z[4:]
+		copy(z, m.sessionTicket)
+		z = z[len(m.sessionTicket):]
+	}
+	if len(m.signatureAndHashes) > 0 {
+		// https://tools.ietf.org/html/rfc5246#section-7.4.1.4.1
+		z[0] = byte(extensionSignatureAlgorithms >> 8)
+		z[1] = byte(extensionSignatureAlgorithms)
+		l := 2 + 2*len(m.signatureAndHashes)
+		z[2] = byte(l >> 8)
+		z[3] = byte(l)
+		z = z[4:]
+
+		l -= 2
+		z[0] = byte(l >> 8)
+		z[1] = byte(l)
+		z = z[2:]
+		for _, sigAndHash := range m.signatureAndHashes {
+			z[0] = sigAndHash.hash
+			z[1] = sigAndHash.signature
+			z = z[2:]
+		}
+	}
+
+	m.raw = x
+
+	return x
+}
+
+func (m *clientHelloMsg) unmarshal(data []byte) bool {
+	if len(data) < 42 {
+		return false
+	}
+	m.raw = data
+	m.vers = uint16(data[4])<<8 | uint16(data[5])
+	m.random = data[6:38]
+	sessionIdLen := int(data[38])
+	if sessionIdLen > 32 || len(data) < 39+sessionIdLen {
+		return false
+	}
+	m.sessionId = data[39 : 39+sessionIdLen]
+	data = data[39+sessionIdLen:]
+	if len(data) < 2 {
+		return false
+	}
+	// cipherSuiteLen is the number of bytes of cipher suite numbers. Since
+	// they are uint16s, the number must be even.
+	cipherSuiteLen := int(data[0])<<8 | int(data[1])
+	if cipherSuiteLen%2 == 1 || len(data) < 2+cipherSuiteLen {
+		return false
+	}
+	numCipherSuites := cipherSuiteLen / 2
+	m.cipherSuites = make([]uint16, numCipherSuites)
+	for i := 0; i < numCipherSuites; i++ {
+		m.cipherSuites[i] = uint16(data[2+2*i])<<8 | uint16(data[3+2*i])
+	}
+	data = data[2+cipherSuiteLen:]
+	if len(data) < 1 {
+		return false
+	}
+	compressionMethodsLen := int(data[0])
+	if len(data) < 1+compressionMethodsLen {
+		return false
+	}
+	m.compressionMethods = data[1 : 1+compressionMethodsLen]
+
+	data = data[1+compressionMethodsLen:]
+
+	m.nextProtoNeg = false
+	m.serverName = ""
+	m.ocspStapling = false
+	m.ticketSupported = false
+	m.sessionTicket = nil
+	m.signatureAndHashes = nil
+
+	if len(data) == 0 {
+		// ClientHello is optionally followed by extension data
+		return true
+	}
+	if len(data) < 2 {
+		return false
+	}
+
+	extensionsLength := int(data[0])<<8 | int(data[1])
+	data = data[2:]
+	if extensionsLength != len(data) {
+		return false
+	}
+
+	for len(data) != 0 {
+		if len(data) < 4 {
+			return false
+		}
+		extension := uint16(data[0])<<8 | uint16(data[1])
+		length := int(data[2])<<8 | int(data[3])
+		data = data[4:]
+		if len(data) < length {
+			return false
+		}
+
+		switch extension {
+		case extensionServerName:
+			if length < 2 {
+				return false
+			}
+			numNames := int(data[0])<<8 | int(data[1])
+			d := data[2:]
+			for i := 0; i < numNames; i++ {
+				if len(d) < 3 {
+					return false
+				}
+				nameType := d[0]
+				nameLen := int(d[1])<<8 | int(d[2])
+				d = d[3:]
+				if len(d) < nameLen {
+					return false
+				}
+				if nameType == 0 {
+					m.serverName = string(d[0:nameLen])
+					break
+				}
+				d = d[nameLen:]
+			}
+		case extensionNextProtoNeg:
+			if length > 0 {
+				return false
+			}
+			m.nextProtoNeg = true
+		case extensionStatusRequest:
+			m.ocspStapling = length > 0 && data[0] == statusTypeOCSP
+		case extensionSupportedCurves:
+			// http://tools.ietf.org/html/rfc4492#section-5.5.1
+			if length < 2 {
+				return false
+			}
+			l := int(data[0])<<8 | int(data[1])
+			if l%2 == 1 || length != l+2 {
+				return false
+			}
+			numCurves := l / 2
+			m.supportedCurves = make([]uint16, numCurves)
+			d := data[2:]
+			for i := 0; i < numCurves; i++ {
+				m.supportedCurves[i] = uint16(d[0])<<8 | uint16(d[1])
+				d = d[2:]
+			}
+		case extensionSupportedPoints:
+			// http://tools.ietf.org/html/rfc4492#section-5.5.2
+			if length < 1 {
+				return false
+			}
+			l := int(data[0])
+			if length != l+1 {
+				return false
+			}
+			m.supportedPoints = make([]uint8, l)
+			copy(m.supportedPoints, data[1:])
+		case extensionSessionTicket:
+			// http://tools.ietf.org/html/rfc5077#section-3.2
+			m.ticketSupported = true
+			m.sessionTicket = data[:length]
+		case extensionSignatureAlgorithms:
+			// https://tools.ietf.org/html/rfc5246#section-7.4.1.4.1
+			if length < 2 || length&1 != 0 {
+				return false
+			}
+			l := int(data[0])<<8 | int(data[1])
+			if l != length-2 {
+				return false
+			}
+			n := l / 2
+			d := data[2:]
+			m.signatureAndHashes = make([]signatureAndHash, n)
+			for i := range m.signatureAndHashes {
+				m.signatureAndHashes[i].hash = d[0]
+				m.signatureAndHashes[i].signature = d[1]
+				d = d[2:]
+			}
+		}
+		data = data[length:]
+	}
+
+	return true
+}
+
+type serverHelloMsg struct {
+	raw               []byte
+	vers              uint16
+	random            []byte
+	sessionId         []byte
+	cipherSuite       uint16
+	compressionMethod uint8
+	nextProtoNeg      bool
+	nextProtos        []string
+	ocspStapling      bool
+	ticketSupported   bool
+}
+
+func (m *serverHelloMsg) equal(i interface{}) bool {
+	m1, ok := i.(*serverHelloMsg)
+	if !ok {
+		return false
+	}
+
+	return bytes.Equal(m.raw, m1.raw) &&
+		m.vers == m1.vers &&
+		bytes.Equal(m.random, m1.random) &&
+		bytes.Equal(m.sessionId, m1.sessionId) &&
+		m.cipherSuite == m1.cipherSuite &&
+		m.compressionMethod == m1.compressionMethod &&
+		m.nextProtoNeg == m1.nextProtoNeg &&
+		eqStrings(m.nextProtos, m1.nextProtos) &&
+		m.ocspStapling == m1.ocspStapling &&
+		m.ticketSupported == m1.ticketSupported
+}
+
+func (m *serverHelloMsg) marshal() []byte {
+	if m.raw != nil {
+		return m.raw
+	}
+
+	length := 38 + len(m.sessionId)
+	numExtensions := 0
+	extensionsLength := 0
+
+	nextProtoLen := 0
+	if m.nextProtoNeg {
+		numExtensions++
+		for _, v := range m.nextProtos {
+			nextProtoLen += len(v)
+		}
+		nextProtoLen += len(m.nextProtos)
+		extensionsLength += nextProtoLen
+	}
+	if m.ocspStapling {
+		numExtensions++
+	}
+	if m.ticketSupported {
+		numExtensions++
+	}
+	if numExtensions > 0 {
+		extensionsLength += 4 * numExtensions
+		length += 2 + extensionsLength
+	}
+
+	x := make([]byte, 4+length)
+	x[0] = typeServerHello
+	x[1] = uint8(length >> 16)
+	x[2] = uint8(length >> 8)
+	x[3] = uint8(length)
+	x[4] = uint8(m.vers >> 8)
+	x[5] = uint8(m.vers)
+	copy(x[6:38], m.random)
+	x[38] = uint8(len(m.sessionId))
+	copy(x[39:39+len(m.sessionId)], m.sessionId)
+	z := x[39+len(m.sessionId):]
+	z[0] = uint8(m.cipherSuite >> 8)
+	z[1] = uint8(m.cipherSuite)
+	z[2] = uint8(m.compressionMethod)
+
+	z = z[3:]
+	if numExtensions > 0 {
+		z[0] = byte(extensionsLength >> 8)
+		z[1] = byte(extensionsLength)
+		z = z[2:]
+	}
+	if m.nextProtoNeg {
+		z[0] = byte(extensionNextProtoNeg >> 8)
+		z[1] = byte(extensionNextProtoNeg)
+		z[2] = byte(nextProtoLen >> 8)
+		z[3] = byte(nextProtoLen)
+		z = z[4:]
+
+		for _, v := range m.nextProtos {
+			l := len(v)
+			if l > 255 {
+				l = 255
+			}
+			z[0] = byte(l)
+			copy(z[1:], []byte(v[0:l]))
+			z = z[1+l:]
+		}
+	}
+	if m.ocspStapling {
+		z[0] = byte(extensionStatusRequest >> 8)
+		z[1] = byte(extensionStatusRequest)
+		z = z[4:]
+	}
+	if m.ticketSupported {
+		z[0] = byte(extensionSessionTicket >> 8)
+		z[1] = byte(extensionSessionTicket)
+		z = z[4:]
+	}
+
+	m.raw = x
+
+	return x
+}
+
+func (m *serverHelloMsg) unmarshal(data []byte) bool {
+	if len(data) < 42 {
+		return false
+	}
+	m.raw = data
+	m.vers = uint16(data[4])<<8 | uint16(data[5])
+	m.random = data[6:38]
+	sessionIdLen := int(data[38])
+	if sessionIdLen > 32 || len(data) < 39+sessionIdLen {
+		return false
+	}
+	m.sessionId = data[39 : 39+sessionIdLen]
+	data = data[39+sessionIdLen:]
+	if len(data) < 3 {
+		return false
+	}
+	m.cipherSuite = uint16(data[0])<<8 | uint16(data[1])
+	m.compressionMethod = data[2]
+	data = data[3:]
+
+	m.nextProtoNeg = false
+	m.nextProtos = nil
+	m.ocspStapling = false
+	m.ticketSupported = false
+
+	if len(data) == 0 {
+		// ServerHello is optionally followed by extension data
+		return true
+	}
+	if len(data) < 2 {
+		return false
+	}
+
+	extensionsLength := int(data[0])<<8 | int(data[1])
+	data = data[2:]
+	if len(data) != extensionsLength {
+		return false
+	}
+
+	for len(data) != 0 {
+		if len(data) < 4 {
+			return false
+		}
+		extension := uint16(data[0])<<8 | uint16(data[1])
+		length := int(data[2])<<8 | int(data[3])
+		data = data[4:]
+		if len(data) < length {
+			return false
+		}
+
+		switch extension {
+		case extensionNextProtoNeg:
+			m.nextProtoNeg = true
+			d := data[:length]
+			for len(d) > 0 {
+				l := int(d[0])
+				d = d[1:]
+				if l == 0 || l > len(d) {
+					return false
+				}
+				m.nextProtos = append(m.nextProtos, string(d[:l]))
+				d = d[l:]
+			}
+		case extensionStatusRequest:
+			if length > 0 {
+				return false
+			}
+			m.ocspStapling = true
+		case extensionSessionTicket:
+			if length > 0 {
+				return false
+			}
+			m.ticketSupported = true
+		}
+		data = data[length:]
+	}
+
+	return true
+}
+
+type certificateMsg struct {
+	raw          []byte
+	certificates [][]byte
+}
+
+func (m *certificateMsg) equal(i interface{}) bool {
+	m1, ok := i.(*certificateMsg)
+	if !ok {
+		return false
+	}
+
+	return bytes.Equal(m.raw, m1.raw) &&
+		eqByteSlices(m.certificates, m1.certificates)
+}
+
+func (m *certificateMsg) marshal() (x []byte) {
+	if m.raw != nil {
+		return m.raw
+	}
+
+	var i int
+	for _, slice := range m.certificates {
+		i += len(slice)
+	}
+
+	length := 3 + 3*len(m.certificates) + i
+	x = make([]byte, 4+length)
+	x[0] = typeCertificate
+	x[1] = uint8(length >> 16)
+	x[2] = uint8(length >> 8)
+	x[3] = uint8(length)
+
+	certificateOctets := length - 3
+	x[4] = uint8(certificateOctets >> 16)
+	x[5] = uint8(certificateOctets >> 8)
+	x[6] = uint8(certificateOctets)
+
+	y := x[7:]
+	for _, slice := range m.certificates {
+		y[0] = uint8(len(slice) >> 16)
+		y[1] = uint8(len(slice) >> 8)
+		y[2] = uint8(len(slice))
+		copy(y[3:], slice)
+		y = y[3+len(slice):]
+	}
+
+	m.raw = x
+	return
+}
+
+func (m *certificateMsg) unmarshal(data []byte) bool {
+	if len(data) < 7 {
+		return false
+	}
+
+	m.raw = data
+	certsLen := uint32(data[4])<<16 | uint32(data[5])<<8 | uint32(data[6])
+	if uint32(len(data)) != certsLen+7 {
+		return false
+	}
+
+	numCerts := 0
+	d := data[7:]
+	for certsLen > 0 {
+		if len(d) < 4 {
+			return false
+		}
+		certLen := uint32(d[0])<<16 | uint32(d[1])<<8 | uint32(d[2])
+		if uint32(len(d)) < 3+certLen {
+			return false
+		}
+		d = d[3+certLen:]
+		certsLen -= 3 + certLen
+		numCerts++
+	}
+
+	m.certificates = make([][]byte, numCerts)
+	d = data[7:]
+	for i := 0; i < numCerts; i++ {
+		certLen := uint32(d[0])<<16 | uint32(d[1])<<8 | uint32(d[2])
+		m.certificates[i] = d[3 : 3+certLen]
+		d = d[3+certLen:]
+	}
+
+	return true
+}
+
+type serverKeyExchangeMsg struct {
+	raw []byte
+	key []byte
+}
+
+func (m *serverKeyExchangeMsg) equal(i interface{}) bool {
+	m1, ok := i.(*serverKeyExchangeMsg)
+	if !ok {
+		return false
+	}
+
+	return bytes.Equal(m.raw, m1.raw) &&
+		bytes.Equal(m.key, m1.key)
+}
+
+func (m *serverKeyExchangeMsg) marshal() []byte {
+	if m.raw != nil {
+		return m.raw
+	}
+	length := len(m.key)
+	x := make([]byte, length+4)
+	x[0] = typeServerKeyExchange
+	x[1] = uint8(length >> 16)
+	x[2] = uint8(length >> 8)
+	x[3] = uint8(length)
+	copy(x[4:], m.key)
+
+	m.raw = x
+	return x
+}
+
+func (m *serverKeyExchangeMsg) unmarshal(data []byte) bool {
+	m.raw = data
+	if len(data) < 4 {
+		return false
+	}
+	m.key = data[4:]
+	return true
+}
+
+type certificateStatusMsg struct {
+	raw        []byte
+	statusType uint8
+	response   []byte
+}
+
+func (m *certificateStatusMsg) equal(i interface{}) bool {
+	m1, ok := i.(*certificateStatusMsg)
+	if !ok {
+		return false
+	}
+
+	return bytes.Equal(m.raw, m1.raw) &&
+		m.statusType == m1.statusType &&
+		bytes.Equal(m.response, m1.response)
+}
+
+func (m *certificateStatusMsg) marshal() []byte {
+	if m.raw != nil {
+		return m.raw
+	}
+
+	var x []byte
+	if m.statusType == statusTypeOCSP {
+		x = make([]byte, 4+4+len(m.response))
+		x[0] = typeCertificateStatus
+		l := len(m.response) + 4
+		x[1] = byte(l >> 16)
+		x[2] = byte(l >> 8)
+		x[3] = byte(l)
+		x[4] = statusTypeOCSP
+
+		l -= 4
+		x[5] = byte(l >> 16)
+		x[6] = byte(l >> 8)
+		x[7] = byte(l)
+		copy(x[8:], m.response)
+	} else {
+		x = []byte{typeCertificateStatus, 0, 0, 1, m.statusType}
+	}
+
+	m.raw = x
+	return x
+}
+
+func (m *certificateStatusMsg) unmarshal(data []byte) bool {
+	m.raw = data
+	if len(data) < 5 {
+		return false
+	}
+	m.statusType = data[4]
+
+	m.response = nil
+	if m.statusType == statusTypeOCSP {
+		if len(data) < 8 {
+			return false
+		}
+		respLen := uint32(data[5])<<16 | uint32(data[6])<<8 | uint32(data[7])
+		if uint32(len(data)) != 4+4+respLen {
+			return false
+		}
+		m.response = data[8:]
+	}
+	return true
+}
+
+type serverHelloDoneMsg struct{}
+
+func (m *serverHelloDoneMsg) equal(i interface{}) bool {
+	_, ok := i.(*serverHelloDoneMsg)
+	return ok
+}
+
+func (m *serverHelloDoneMsg) marshal() []byte {
+	x := make([]byte, 4)
+	x[0] = typeServerHelloDone
+	return x
+}
+
+func (m *serverHelloDoneMsg) unmarshal(data []byte) bool {
+	return len(data) == 4
+}
+
+type clientKeyExchangeMsg struct {
+	raw        []byte
+	ciphertext []byte
+}
+
+func (m *clientKeyExchangeMsg) equal(i interface{}) bool {
+	m1, ok := i.(*clientKeyExchangeMsg)
+	if !ok {
+		return false
+	}
+
+	return bytes.Equal(m.raw, m1.raw) &&
+		bytes.Equal(m.ciphertext, m1.ciphertext)
+}
+
+func (m *clientKeyExchangeMsg) marshal() []byte {
+	if m.raw != nil {
+		return m.raw
+	}
+	length := len(m.ciphertext)
+	x := make([]byte, length+4)
+	x[0] = typeClientKeyExchange
+	x[1] = uint8(length >> 16)
+	x[2] = uint8(length >> 8)
+	x[3] = uint8(length)
+	copy(x[4:], m.ciphertext)
+
+	m.raw = x
+	return x
+}
+
+func (m *clientKeyExchangeMsg) unmarshal(data []byte) bool {
+	m.raw = data
+	if len(data) < 4 {
+		return false
+	}
+	l := int(data[1])<<16 | int(data[2])<<8 | int(data[3])
+	if l != len(data)-4 {
+		return false
+	}
+	m.ciphertext = data[4:]
+	return true
+}
+
+type finishedMsg struct {
+	raw        []byte
+	verifyData []byte
+}
+
+func (m *finishedMsg) equal(i interface{}) bool {
+	m1, ok := i.(*finishedMsg)
+	if !ok {
+		return false
+	}
+
+	return bytes.Equal(m.raw, m1.raw) &&
+		bytes.Equal(m.verifyData, m1.verifyData)
+}
+
+func (m *finishedMsg) marshal() (x []byte) {
+	if m.raw != nil {
+		return m.raw
+	}
+
+	x = make([]byte, 4+len(m.verifyData))
+	x[0] = typeFinished
+	x[3] = byte(len(m.verifyData))
+	copy(x[4:], m.verifyData)
+	m.raw = x
+	return
+}
+
+func (m *finishedMsg) unmarshal(data []byte) bool {
+	m.raw = data
+	if len(data) < 4 {
+		return false
+	}
+	m.verifyData = data[4:]
+	return true
+}
+
+type nextProtoMsg struct {
+	raw   []byte
+	proto string
+}
+
+func (m *nextProtoMsg) equal(i interface{}) bool {
+	m1, ok := i.(*nextProtoMsg)
+	if !ok {
+		return false
+	}
+
+	return bytes.Equal(m.raw, m1.raw) &&
+		m.proto == m1.proto
+}
+
+func (m *nextProtoMsg) marshal() []byte {
+	if m.raw != nil {
+		return m.raw
+	}
+	l := len(m.proto)
+	if l > 255 {
+		l = 255
+	}
+
+	padding := 32 - (l+2)%32
+	length := l + padding + 2
+	x := make([]byte, length+4)
+	x[0] = typeNextProtocol
+	x[1] = uint8(length >> 16)
+	x[2] = uint8(length >> 8)
+	x[3] = uint8(length)
+
+	y := x[4:]
+	y[0] = byte(l)
+	copy(y[1:], []byte(m.proto[0:l]))
+	y = y[1+l:]
+	y[0] = byte(padding)
+
+	m.raw = x
+
+	return x
+}
+
+func (m *nextProtoMsg) unmarshal(data []byte) bool {
+	m.raw = data
+
+	if len(data) < 5 {
+		return false
+	}
+	data = data[4:]
+	protoLen := int(data[0])
+	data = data[1:]
+	if len(data) < protoLen {
+		return false
+	}
+	m.proto = string(data[0:protoLen])
+	data = data[protoLen:]
+
+	if len(data) < 1 {
+		return false
+	}
+	paddingLen := int(data[0])
+	data = data[1:]
+	if len(data) != paddingLen {
+		return false
+	}
+
+	return true
+}
+
+type certificateRequestMsg struct {
+	raw []byte
+	// hasSignatureAndHash indicates whether this message includes a list
+	// of signature and hash functions. This change was introduced with TLS
+	// 1.2.
+	hasSignatureAndHash bool
+
+	certificateTypes       []byte
+	signatureAndHashes     []signatureAndHash
+	certificateAuthorities [][]byte
+}
+
+func (m *certificateRequestMsg) equal(i interface{}) bool {
+	m1, ok := i.(*certificateRequestMsg)
+	if !ok {
+		return false
+	}
+
+	return bytes.Equal(m.raw, m1.raw) &&
+		bytes.Equal(m.certificateTypes, m1.certificateTypes) &&
+		eqByteSlices(m.certificateAuthorities, m1.certificateAuthorities) &&
+		eqSignatureAndHashes(m.signatureAndHashes, m1.signatureAndHashes)
+}
+
+func (m *certificateRequestMsg) marshal() (x []byte) {
+	if m.raw != nil {
+		return m.raw
+	}
+
+	// See http://tools.ietf.org/html/rfc4346#section-7.4.4
+	length := 1 + len(m.certificateTypes) + 2
+	casLength := 0
+	for _, ca := range m.certificateAuthorities {
+		casLength += 2 + len(ca)
+	}
+	length += casLength
+
+	if m.hasSignatureAndHash {
+		length += 2 + 2*len(m.signatureAndHashes)
+	}
+
+	x = make([]byte, 4+length)
+	x[0] = typeCertificateRequest
+	x[1] = uint8(length >> 16)
+	x[2] = uint8(length >> 8)
+	x[3] = uint8(length)
+
+	x[4] = uint8(len(m.certificateTypes))
+
+	copy(x[5:], m.certificateTypes)
+	y := x[5+len(m.certificateTypes):]
+
+	if m.hasSignatureAndHash {
+		n := len(m.signatureAndHashes) * 2
+		y[0] = uint8(n >> 8)
+		y[1] = uint8(n)
+		y = y[2:]
+		for _, sigAndHash := range m.signatureAndHashes {
+			y[0] = sigAndHash.hash
+			y[1] = sigAndHash.signature
+			y = y[2:]
+		}
+	}
+
+	y[0] = uint8(casLength >> 8)
+	y[1] = uint8(casLength)
+	y = y[2:]
+	for _, ca := range m.certificateAuthorities {
+		y[0] = uint8(len(ca) >> 8)
+		y[1] = uint8(len(ca))
+		y = y[2:]
+		copy(y, ca)
+		y = y[len(ca):]
+	}
+
+	m.raw = x
+	return
+}
+
+func (m *certificateRequestMsg) unmarshal(data []byte) bool {
+	m.raw = data
+
+	if len(data) < 5 {
+		return false
+	}
+
+	length := uint32(data[1])<<16 | uint32(data[2])<<8 | uint32(data[3])
+	if uint32(len(data))-4 != length {
+		return false
+	}
+
+	numCertTypes := int(data[4])
+	data = data[5:]
+	if numCertTypes == 0 || len(data) <= numCertTypes {
+		return false
+	}
+
+	m.certificateTypes = make([]byte, numCertTypes)
+	if copy(m.certificateTypes, data) != numCertTypes {
+		return false
+	}
+
+	data = data[numCertTypes:]
+
+	if m.hasSignatureAndHash {
+		if len(data) < 2 {
+			return false
+		}
+		sigAndHashLen := uint16(data[0])<<8 | uint16(data[1])
+		data = data[2:]
+		if sigAndHashLen&1 != 0 {
+			return false
+		}
+		if len(data) < int(sigAndHashLen) {
+			return false
+		}
+		numSigAndHash := sigAndHashLen / 2
+		m.signatureAndHashes = make([]signatureAndHash, numSigAndHash)
+		for i := range m.signatureAndHashes {
+			m.signatureAndHashes[i].hash = data[0]
+			m.signatureAndHashes[i].signature = data[1]
+			data = data[2:]
+		}
+	}
+
+	if len(data) < 2 {
+		return false
+	}
+	casLength := uint16(data[0])<<8 | uint16(data[1])
+	data = data[2:]
+	if len(data) < int(casLength) {
+		return false
+	}
+	cas := make([]byte, casLength)
+	copy(cas, data)
+	data = data[casLength:]
+
+	m.certificateAuthorities = nil
+	for len(cas) > 0 {
+		if len(cas) < 2 {
+			return false
+		}
+		caLen := uint16(cas[0])<<8 | uint16(cas[1])
+		cas = cas[2:]
+
+		if len(cas) < int(caLen) {
+			return false
+		}
+
+		m.certificateAuthorities = append(m.certificateAuthorities, cas[:caLen])
+		cas = cas[caLen:]
+	}
+	if len(data) > 0 {
+		return false
+	}
+
+	return true
+}
+
+type certificateVerifyMsg struct {
+	raw                 []byte
+	hasSignatureAndHash bool
+	signatureAndHash    signatureAndHash
+	signature           []byte
+}
+
+func (m *certificateVerifyMsg) equal(i interface{}) bool {
+	m1, ok := i.(*certificateVerifyMsg)
+	if !ok {
+		return false
+	}
+
+	return bytes.Equal(m.raw, m1.raw) &&
+		m.hasSignatureAndHash == m1.hasSignatureAndHash &&
+		m.signatureAndHash.hash == m1.signatureAndHash.hash &&
+		m.signatureAndHash.signature == m1.signatureAndHash.signature &&
+		bytes.Equal(m.signature, m1.signature)
+}
+
+func (m *certificateVerifyMsg) marshal() (x []byte) {
+	if m.raw != nil {
+		return m.raw
+	}
+
+	// See http://tools.ietf.org/html/rfc4346#section-7.4.8
+	siglength := len(m.signature)
+	length := 2 + siglength
+	if m.hasSignatureAndHash {
+		length += 2
+	}
+	x = make([]byte, 4+length)
+	x[0] = typeCertificateVerify
+	x[1] = uint8(length >> 16)
+	x[2] = uint8(length >> 8)
+	x[3] = uint8(length)
+	y := x[4:]
+	if m.hasSignatureAndHash {
+		y[0] = m.signatureAndHash.hash
+		y[1] = m.signatureAndHash.signature
+		y = y[2:]
+	}
+	y[0] = uint8(siglength >> 8)
+	y[1] = uint8(siglength)
+	copy(y[2:], m.signature)
+
+	m.raw = x
+
+	return
+}
+
+func (m *certificateVerifyMsg) unmarshal(data []byte) bool {
+	m.raw = data
+
+	if len(data) < 6 {
+		return false
+	}
+
+	length := uint32(data[1])<<16 | uint32(data[2])<<8 | uint32(data[3])
+	if uint32(len(data))-4 != length {
+		return false
+	}
+
+	data = data[4:]
+	if m.hasSignatureAndHash {
+		m.signatureAndHash.hash = data[0]
+		m.signatureAndHash.signature = data[1]
+		data = data[2:]
+	}
+
+	if len(data) < 2 {
+		return false
+	}
+	siglength := int(data[0])<<8 + int(data[1])
+	data = data[2:]
+	if len(data) != siglength {
+		return false
+	}
+
+	m.signature = data
+
+	return true
+}
+
+type newSessionTicketMsg struct {
+	raw    []byte
+	ticket []byte
+}
+
+func (m *newSessionTicketMsg) equal(i interface{}) bool {
+	m1, ok := i.(*newSessionTicketMsg)
+	if !ok {
+		return false
+	}
+
+	return bytes.Equal(m.raw, m1.raw) &&
+		bytes.Equal(m.ticket, m1.ticket)
+}
+
+func (m *newSessionTicketMsg) marshal() (x []byte) {
+	if m.raw != nil {
+		return m.raw
+	}
+
+	// See http://tools.ietf.org/html/rfc5077#section-3.3
+	ticketLen := len(m.ticket)
+	length := 2 + 4 + ticketLen
+	x = make([]byte, 4+length)
+	x[0] = typeNewSessionTicket
+	x[1] = uint8(length >> 16)
+	x[2] = uint8(length >> 8)
+	x[3] = uint8(length)
+	x[8] = uint8(ticketLen >> 8)
+	x[9] = uint8(ticketLen)
+	copy(x[10:], m.ticket)
+
+	m.raw = x
+
+	return
+}
+
+func (m *newSessionTicketMsg) unmarshal(data []byte) bool {
+	m.raw = data
+
+	if len(data) < 10 {
+		return false
+	}
+
+	length := uint32(data[1])<<16 | uint32(data[2])<<8 | uint32(data[3])
+	if uint32(len(data))-4 != length {
+		return false
+	}
+
+	ticketLen := int(data[8])<<8 + int(data[9])
+	if len(data)-10 != ticketLen {
+		return false
+	}
+
+	m.ticket = data[10:]
+
+	return true
+}
+
+type helloRequestMsg struct {
+}
+
+func (*helloRequestMsg) marshal() []byte {
+	return []byte{typeHelloRequest, 0, 0, 0}
+}
+
+func (*helloRequestMsg) unmarshal(data []byte) bool {
+	return len(data) == 4
+}
+
+func eqUint16s(x, y []uint16) bool {
+	if len(x) != len(y) {
+		return false
+	}
+	for i, v := range x {
+		if y[i] != v {
+			return false
+		}
+	}
+	return true
+}
+
+func eqStrings(x, y []string) bool {
+	if len(x) != len(y) {
+		return false
+	}
+	for i, v := range x {
+		if y[i] != v {
+			return false
+		}
+	}
+	return true
+}
+
+func eqByteSlices(x, y [][]byte) bool {
+	if len(x) != len(y) {
+		return false
+	}
+	for i, v := range x {
+		if !bytes.Equal(v, y[i]) {
+			return false
+		}
+	}
+	return true
+}
+
+func eqSignatureAndHashes(x, y []signatureAndHash) bool {
+	if len(x) != len(y) {
+		return false
+	}
+	for i, v := range x {
+		v2 := y[i]
+		if v.hash != v2.hash || v.signature != v2.signature {
+			return false
+		}
+	}
+	return true
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/handshake_server.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/handshake_server.go
new file mode 100644
index 000000000..c9ccf675c
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/handshake_server.go
@@ -0,0 +1,638 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package tls
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/rsa"
+	"crypto/subtle"
+	"crypto/x509"
+	"encoding/asn1"
+	"errors"
+	"io"
+)
+
+// serverHandshakeState contains details of a server handshake in progress.
+// It's discarded once the handshake has completed.
+type serverHandshakeState struct {
+	c               *Conn
+	clientHello     *clientHelloMsg
+	hello           *serverHelloMsg
+	suite           *cipherSuite
+	ellipticOk      bool
+	ecdsaOk         bool
+	sessionState    *sessionState
+	finishedHash    finishedHash
+	masterSecret    []byte
+	certsFromClient [][]byte
+	cert            *Certificate
+}
+
+// serverHandshake performs a TLS handshake as a server.
+func (c *Conn) serverHandshake() error {
+	config := c.config
+
+	// If this is the first server handshake, we generate a random key to
+	// encrypt the tickets with.
+	config.serverInitOnce.Do(config.serverInit)
+
+	hs := serverHandshakeState{
+		c: c,
+	}
+	isResume, err := hs.readClientHello()
+	if err != nil {
+		return err
+	}
+
+	// For an overview of TLS handshaking, see https://tools.ietf.org/html/rfc5246#section-7.3
+	if isResume {
+		// The client has included a session ticket and so we do an abbreviated handshake.
+		if err := hs.doResumeHandshake(); err != nil {
+			return err
+		}
+		if err := hs.establishKeys(); err != nil {
+			return err
+		}
+		if err := hs.sendFinished(); err != nil {
+			return err
+		}
+		if err := hs.readFinished(); err != nil {
+			return err
+		}
+		c.didResume = true
+	} else {
+		// The client didn't include a session ticket, or it wasn't
+		// valid so we do a full handshake.
+		if err := hs.doFullHandshake(); err != nil {
+			return err
+		}
+		if err := hs.establishKeys(); err != nil {
+			return err
+		}
+		if err := hs.readFinished(); err != nil {
+			return err
+		}
+		if err := hs.sendSessionTicket(); err != nil {
+			return err
+		}
+		if err := hs.sendFinished(); err != nil {
+			return err
+		}
+	}
+	c.handshakeComplete = true
+
+	return nil
+}
+
+// readClientHello reads a ClientHello message from the client and decides
+// whether we will perform session resumption.
+func (hs *serverHandshakeState) readClientHello() (isResume bool, err error) {
+	config := hs.c.config
+	c := hs.c
+
+	msg, err := c.readHandshake()
+	if err != nil {
+		return false, err
+	}
+	var ok bool
+	hs.clientHello, ok = msg.(*clientHelloMsg)
+	if !ok {
+		return false, c.sendAlert(alertUnexpectedMessage)
+	}
+	c.vers, ok = config.mutualVersion(hs.clientHello.vers)
+	if !ok {
+		return false, c.sendAlert(alertProtocolVersion)
+	}
+	c.haveVers = true
+
+	hs.finishedHash = newFinishedHash(c.vers)
+	hs.finishedHash.Write(hs.clientHello.marshal())
+
+	hs.hello = new(serverHelloMsg)
+
+	supportedCurve := false
+Curves:
+	for _, curve := range hs.clientHello.supportedCurves {
+		switch curve {
+		case curveP256, curveP384, curveP521:
+			supportedCurve = true
+			break Curves
+		}
+	}
+
+	supportedPointFormat := false
+	for _, pointFormat := range hs.clientHello.supportedPoints {
+		if pointFormat == pointFormatUncompressed {
+			supportedPointFormat = true
+			break
+		}
+	}
+	hs.ellipticOk = supportedCurve && supportedPointFormat
+
+	foundCompression := false
+	// We only support null compression, so check that the client offered it.
+	for _, compression := range hs.clientHello.compressionMethods {
+		if compression == compressionNone {
+			foundCompression = true
+			break
+		}
+	}
+
+	if !foundCompression {
+		return false, c.sendAlert(alertHandshakeFailure)
+	}
+
+	hs.hello.vers = c.vers
+	t := uint32(config.time().Unix())
+	hs.hello.random = make([]byte, 32)
+	hs.hello.random[0] = byte(t >> 24)
+	hs.hello.random[1] = byte(t >> 16)
+	hs.hello.random[2] = byte(t >> 8)
+	hs.hello.random[3] = byte(t)
+	_, err = io.ReadFull(config.rand(), hs.hello.random[4:])
+	if err != nil {
+		return false, c.sendAlert(alertInternalError)
+	}
+	hs.hello.compressionMethod = compressionNone
+	if len(hs.clientHello.serverName) > 0 {
+		c.serverName = hs.clientHello.serverName
+	}
+	// Although sending an empty NPN extension is reasonable, Firefox has
+	// had a bug around this. Best to send nothing at all if
+	// config.NextProtos is empty. See
+	// https://code.google.com/p/go/issues/detail?id=5445.
+	if hs.clientHello.nextProtoNeg && len(config.NextProtos) > 0 {
+		hs.hello.nextProtoNeg = true
+		hs.hello.nextProtos = config.NextProtos
+	}
+
+	if len(config.Certificates) == 0 {
+		return false, c.sendAlert(alertInternalError)
+	}
+	hs.cert = &config.Certificates[0]
+	if len(hs.clientHello.serverName) > 0 {
+		hs.cert = config.getCertificateForName(hs.clientHello.serverName)
+	}
+
+	_, hs.ecdsaOk = hs.cert.PrivateKey.(*ecdsa.PrivateKey)
+
+	if hs.checkForResumption() {
+		return true, nil
+	}
+
+	var preferenceList, supportedList []uint16
+	if c.config.PreferServerCipherSuites {
+		preferenceList = c.config.cipherSuites()
+		supportedList = hs.clientHello.cipherSuites
+	} else {
+		preferenceList = hs.clientHello.cipherSuites
+		supportedList = c.config.cipherSuites()
+	}
+
+	for _, id := range preferenceList {
+		if hs.suite = c.tryCipherSuite(id, supportedList, c.vers, hs.ellipticOk, hs.ecdsaOk); hs.suite != nil {
+			break
+		}
+	}
+
+	if hs.suite == nil {
+		return false, c.sendAlert(alertHandshakeFailure)
+	}
+
+	return false, nil
+}
+
+// checkForResumption returns true if we should perform resumption on this connection.
+func (hs *serverHandshakeState) checkForResumption() bool {
+	c := hs.c
+
+	var ok bool
+	if hs.sessionState, ok = c.decryptTicket(hs.clientHello.sessionTicket); !ok {
+		return false
+	}
+
+	if hs.sessionState.vers > hs.clientHello.vers {
+		return false
+	}
+	if vers, ok := c.config.mutualVersion(hs.sessionState.vers); !ok || vers != hs.sessionState.vers {
+		return false
+	}
+
+	cipherSuiteOk := false
+	// Check that the client is still offering the ciphersuite in the session.
+	for _, id := range hs.clientHello.cipherSuites {
+		if id == hs.sessionState.cipherSuite {
+			cipherSuiteOk = true
+			break
+		}
+	}
+	if !cipherSuiteOk {
+		return false
+	}
+
+	// Check that we also support the ciphersuite from the session.
+	hs.suite = c.tryCipherSuite(hs.sessionState.cipherSuite, c.config.cipherSuites(), hs.sessionState.vers, hs.ellipticOk, hs.ecdsaOk)
+	if hs.suite == nil {
+		return false
+	}
+
+	sessionHasClientCerts := len(hs.sessionState.certificates) != 0
+	needClientCerts := c.config.ClientAuth == RequireAnyClientCert || c.config.ClientAuth == RequireAndVerifyClientCert
+	if needClientCerts && !sessionHasClientCerts {
+		return false
+	}
+	if sessionHasClientCerts && c.config.ClientAuth == NoClientCert {
+		return false
+	}
+
+	return true
+}
+
+func (hs *serverHandshakeState) doResumeHandshake() error {
+	c := hs.c
+
+	hs.hello.cipherSuite = hs.suite.id
+	// We echo the client's session ID in the ServerHello to let it know
+	// that we're doing a resumption.
+	hs.hello.sessionId = hs.clientHello.sessionId
+	hs.finishedHash.Write(hs.hello.marshal())
+	c.writeRecord(recordTypeHandshake, hs.hello.marshal())
+
+	if len(hs.sessionState.certificates) > 0 {
+		if _, err := hs.processCertsFromClient(hs.sessionState.certificates); err != nil {
+			return err
+		}
+	}
+
+	hs.masterSecret = hs.sessionState.masterSecret
+
+	return nil
+}
+
+func (hs *serverHandshakeState) doFullHandshake() error {
+	config := hs.c.config
+	c := hs.c
+
+	if hs.clientHello.ocspStapling && len(hs.cert.OCSPStaple) > 0 {
+		hs.hello.ocspStapling = true
+	}
+
+	hs.hello.ticketSupported = hs.clientHello.ticketSupported && !config.SessionTicketsDisabled
+	hs.hello.cipherSuite = hs.suite.id
+	hs.finishedHash.Write(hs.hello.marshal())
+	c.writeRecord(recordTypeHandshake, hs.hello.marshal())
+
+	certMsg := new(certificateMsg)
+	certMsg.certificates = hs.cert.Certificate
+	hs.finishedHash.Write(certMsg.marshal())
+	c.writeRecord(recordTypeHandshake, certMsg.marshal())
+
+	if hs.hello.ocspStapling {
+		certStatus := new(certificateStatusMsg)
+		certStatus.statusType = statusTypeOCSP
+		certStatus.response = hs.cert.OCSPStaple
+		hs.finishedHash.Write(certStatus.marshal())
+		c.writeRecord(recordTypeHandshake, certStatus.marshal())
+	}
+
+	keyAgreement := hs.suite.ka(c.vers)
+	skx, err := keyAgreement.generateServerKeyExchange(config, hs.cert, hs.clientHello, hs.hello)
+	if err != nil {
+		c.sendAlert(alertHandshakeFailure)
+		return err
+	}
+	if skx != nil {
+		hs.finishedHash.Write(skx.marshal())
+		c.writeRecord(recordTypeHandshake, skx.marshal())
+	}
+
+	if config.ClientAuth >= RequestClientCert {
+		// Request a client certificate
+		certReq := new(certificateRequestMsg)
+		certReq.certificateTypes = []byte{
+			byte(certTypeRSASign),
+			byte(certTypeECDSASign),
+		}
+		if c.vers >= VersionTLS12 {
+			certReq.hasSignatureAndHash = true
+			certReq.signatureAndHashes = supportedClientCertSignatureAlgorithms
+		}
+
+		// An empty list of certificateAuthorities signals to
+		// the client that it may send any certificate in response
+		// to our request. When we know the CAs we trust, then
+		// we can send them down, so that the client can choose
+		// an appropriate certificate to give to us.
+		if config.ClientCAs != nil {
+			certReq.certificateAuthorities = config.ClientCAs.Subjects()
+		}
+		hs.finishedHash.Write(certReq.marshal())
+		c.writeRecord(recordTypeHandshake, certReq.marshal())
+	}
+
+	helloDone := new(serverHelloDoneMsg)
+	hs.finishedHash.Write(helloDone.marshal())
+	c.writeRecord(recordTypeHandshake, helloDone.marshal())
+
+	var pub crypto.PublicKey // public key for client auth, if any
+
+	msg, err := c.readHandshake()
+	if err != nil {
+		return err
+	}
+
+	var ok bool
+	// If we requested a client certificate, then the client must send a
+	// certificate message, even if it's empty.
+	if config.ClientAuth >= RequestClientCert {
+		if certMsg, ok = msg.(*certificateMsg); !ok {
+			return c.sendAlert(alertHandshakeFailure)
+		}
+		hs.finishedHash.Write(certMsg.marshal())
+
+		if len(certMsg.certificates) == 0 {
+			// The client didn't actually send a certificate
+			switch config.ClientAuth {
+			case RequireAnyClientCert, RequireAndVerifyClientCert:
+				c.sendAlert(alertBadCertificate)
+				return errors.New("tls: client didn't provide a certificate")
+			}
+		}
+
+		pub, err = hs.processCertsFromClient(certMsg.certificates)
+		if err != nil {
+			return err
+		}
+
+		msg, err = c.readHandshake()
+		if err != nil {
+			return err
+		}
+	}
+
+	// Get client key exchange
+	ckx, ok := msg.(*clientKeyExchangeMsg)
+	if !ok {
+		return c.sendAlert(alertUnexpectedMessage)
+	}
+	hs.finishedHash.Write(ckx.marshal())
+
+	// If we received a client cert in response to our certificate request message,
+	// the client will send us a certificateVerifyMsg immediately after the
+	// clientKeyExchangeMsg.  This message is a digest of all preceding
+	// handshake-layer messages that is signed using the private key corresponding
+	// to the client's certificate. This allows us to verify that the client is in
+	// possession of the private key of the certificate.
+	if len(c.peerCertificates) > 0 {
+		msg, err = c.readHandshake()
+		if err != nil {
+			return err
+		}
+		certVerify, ok := msg.(*certificateVerifyMsg)
+		if !ok {
+			return c.sendAlert(alertUnexpectedMessage)
+		}
+
+		switch key := pub.(type) {
+		case *ecdsa.PublicKey:
+			ecdsaSig := new(ecdsaSignature)
+			if _, err = asn1.Unmarshal(certVerify.signature, ecdsaSig); err != nil {
+				break
+			}
+			if ecdsaSig.R.Sign() <= 0 || ecdsaSig.S.Sign() <= 0 {
+				err = errors.New("ECDSA signature contained zero or negative values")
+				break
+			}
+			digest, _, _ := hs.finishedHash.hashForClientCertificate(signatureECDSA)
+			if !ecdsa.Verify(key, digest, ecdsaSig.R, ecdsaSig.S) {
+				err = errors.New("ECDSA verification failure")
+				break
+			}
+		case *rsa.PublicKey:
+			digest, hashFunc, _ := hs.finishedHash.hashForClientCertificate(signatureRSA)
+			err = rsa.VerifyPKCS1v15(key, hashFunc, digest, certVerify.signature)
+		}
+		if err != nil {
+			c.sendAlert(alertBadCertificate)
+			return errors.New("could not validate signature of connection nonces: " + err.Error())
+		}
+
+		hs.finishedHash.Write(certVerify.marshal())
+	}
+
+	preMasterSecret, err := keyAgreement.processClientKeyExchange(config, hs.cert, ckx, c.vers)
+	if err != nil {
+		c.sendAlert(alertHandshakeFailure)
+		return err
+	}
+	hs.masterSecret = masterFromPreMasterSecret(c.vers, preMasterSecret, hs.clientHello.random, hs.hello.random)
+
+	return nil
+}
+
+func (hs *serverHandshakeState) establishKeys() error {
+	c := hs.c
+
+	clientMAC, serverMAC, clientKey, serverKey, clientIV, serverIV :=
+		keysFromMasterSecret(c.vers, hs.masterSecret, hs.clientHello.random, hs.hello.random, hs.suite.macLen, hs.suite.keyLen, hs.suite.ivLen)
+
+	var clientCipher, serverCipher interface{}
+	var clientHash, serverHash macFunction
+
+	if hs.suite.aead == nil {
+		clientCipher = hs.suite.cipher(clientKey, clientIV, true /* for reading */)
+		clientHash = hs.suite.mac(c.vers, clientMAC)
+		serverCipher = hs.suite.cipher(serverKey, serverIV, false /* not for reading */)
+		serverHash = hs.suite.mac(c.vers, serverMAC)
+	} else {
+		clientCipher = hs.suite.aead(clientKey, clientIV)
+		serverCipher = hs.suite.aead(serverKey, serverIV)
+	}
+
+	c.in.prepareCipherSpec(c.vers, clientCipher, clientHash)
+	c.out.prepareCipherSpec(c.vers, serverCipher, serverHash)
+
+	return nil
+}
+
+func (hs *serverHandshakeState) readFinished() error {
+	c := hs.c
+
+	c.readRecord(recordTypeChangeCipherSpec)
+	if err := c.error(); err != nil {
+		return err
+	}
+
+	if hs.hello.nextProtoNeg {
+		msg, err := c.readHandshake()
+		if err != nil {
+			return err
+		}
+		nextProto, ok := msg.(*nextProtoMsg)
+		if !ok {
+			return c.sendAlert(alertUnexpectedMessage)
+		}
+		hs.finishedHash.Write(nextProto.marshal())
+		c.clientProtocol = nextProto.proto
+	}
+
+	msg, err := c.readHandshake()
+	if err != nil {
+		return err
+	}
+	clientFinished, ok := msg.(*finishedMsg)
+	if !ok {
+		return c.sendAlert(alertUnexpectedMessage)
+	}
+
+	verify := hs.finishedHash.clientSum(hs.masterSecret)
+	if len(verify) != len(clientFinished.verifyData) ||
+		subtle.ConstantTimeCompare(verify, clientFinished.verifyData) != 1 {
+		return c.sendAlert(alertHandshakeFailure)
+	}
+
+	hs.finishedHash.Write(clientFinished.marshal())
+	return nil
+}
+
+func (hs *serverHandshakeState) sendSessionTicket() error {
+	if !hs.hello.ticketSupported {
+		return nil
+	}
+
+	c := hs.c
+	m := new(newSessionTicketMsg)
+
+	var err error
+	state := sessionState{
+		vers:         c.vers,
+		cipherSuite:  hs.suite.id,
+		masterSecret: hs.masterSecret,
+		certificates: hs.certsFromClient,
+	}
+	m.ticket, err = c.encryptTicket(&state)
+	if err != nil {
+		return err
+	}
+
+	hs.finishedHash.Write(m.marshal())
+	c.writeRecord(recordTypeHandshake, m.marshal())
+
+	return nil
+}
+
+func (hs *serverHandshakeState) sendFinished() error {
+	c := hs.c
+
+	c.writeRecord(recordTypeChangeCipherSpec, []byte{1})
+
+	finished := new(finishedMsg)
+	finished.verifyData = hs.finishedHash.serverSum(hs.masterSecret)
+	hs.finishedHash.Write(finished.marshal())
+	c.writeRecord(recordTypeHandshake, finished.marshal())
+
+	c.cipherSuite = hs.suite.id
+
+	return nil
+}
+
+// processCertsFromClient takes a chain of client certificates either from a
+// Certificates message or from a sessionState and verifies them. It returns
+// the public key of the leaf certificate.
+func (hs *serverHandshakeState) processCertsFromClient(certificates [][]byte) (crypto.PublicKey, error) {
+	c := hs.c
+
+	hs.certsFromClient = certificates
+	certs := make([]*x509.Certificate, len(certificates))
+	var err error
+	for i, asn1Data := range certificates {
+		if certs[i], err = x509.ParseCertificate(asn1Data); err != nil {
+			c.sendAlert(alertBadCertificate)
+			return nil, errors.New("tls: failed to parse client certificate: " + err.Error())
+		}
+	}
+
+	if c.config.ClientAuth >= VerifyClientCertIfGiven && len(certs) > 0 {
+		opts := x509.VerifyOptions{
+			Roots:         c.config.ClientCAs,
+			CurrentTime:   c.config.time(),
+			Intermediates: x509.NewCertPool(),
+			KeyUsages:     []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth},
+		}
+
+		for _, cert := range certs[1:] {
+			opts.Intermediates.AddCert(cert)
+		}
+
+		chains, err := certs[0].Verify(opts)
+		if err != nil {
+			c.sendAlert(alertBadCertificate)
+			return nil, errors.New("tls: failed to verify client's certificate: " + err.Error())
+		}
+
+		ok := false
+		for _, ku := range certs[0].ExtKeyUsage {
+			if ku == x509.ExtKeyUsageClientAuth {
+				ok = true
+				break
+			}
+		}
+		if !ok {
+			c.sendAlert(alertHandshakeFailure)
+			return nil, errors.New("tls: client's certificate's extended key usage doesn't permit it to be used for client authentication")
+		}
+
+		c.verifiedChains = chains
+	}
+
+	if len(certs) > 0 {
+		var pub crypto.PublicKey
+		switch key := certs[0].PublicKey.(type) {
+		case *ecdsa.PublicKey, *rsa.PublicKey:
+			pub = key
+		default:
+			return nil, c.sendAlert(alertUnsupportedCertificate)
+		}
+		c.peerCertificates = certs
+		return pub, nil
+	}
+
+	return nil, nil
+}
+
+// tryCipherSuite returns a cipherSuite with the given id if that cipher suite
+// is acceptable to use.
+func (c *Conn) tryCipherSuite(id uint16, supportedCipherSuites []uint16, version uint16, ellipticOk, ecdsaOk bool) *cipherSuite {
+	for _, supported := range supportedCipherSuites {
+		if id == supported {
+			var candidate *cipherSuite
+
+			for _, s := range cipherSuites {
+				if s.id == id {
+					candidate = s
+					break
+				}
+			}
+			if candidate == nil {
+				continue
+			}
+			// Don't select a ciphersuite which we can't
+			// support for this client.
+			if (candidate.flags&suiteECDHE != 0) && !ellipticOk {
+				continue
+			}
+			if (candidate.flags&suiteECDSA != 0) != ecdsaOk {
+				continue
+			}
+			if version < VersionTLS12 && candidate.flags&suiteTLS12 != 0 {
+				continue
+			}
+			return candidate
+		}
+	}
+
+	return nil
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/key_agreement.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/key_agreement.go
new file mode 100644
index 000000000..7e820c1e7
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/key_agreement.go
@@ -0,0 +1,400 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package tls
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/md5"
+	"crypto/rsa"
+	"crypto/sha1"
+	"crypto/sha256"
+	"crypto/x509"
+	"encoding/asn1"
+	"errors"
+	"io"
+	"math/big"
+)
+
+// rsaKeyAgreement implements the standard TLS key agreement where the client
+// encrypts the pre-master secret to the server's public key.
+type rsaKeyAgreement struct{}
+
+func (ka rsaKeyAgreement) generateServerKeyExchange(config *Config, cert *Certificate, clientHello *clientHelloMsg, hello *serverHelloMsg) (*serverKeyExchangeMsg, error) {
+	return nil, nil
+}
+
+func (ka rsaKeyAgreement) processClientKeyExchange(config *Config, cert *Certificate, ckx *clientKeyExchangeMsg, version uint16) ([]byte, error) {
+	preMasterSecret := make([]byte, 48)
+	_, err := io.ReadFull(config.rand(), preMasterSecret[2:])
+	if err != nil {
+		return nil, err
+	}
+
+	if len(ckx.ciphertext) < 2 {
+		return nil, errors.New("bad ClientKeyExchange")
+	}
+
+	ciphertext := ckx.ciphertext
+	if version != VersionSSL30 {
+		ciphertextLen := int(ckx.ciphertext[0])<<8 | int(ckx.ciphertext[1])
+		if ciphertextLen != len(ckx.ciphertext)-2 {
+			return nil, errors.New("bad ClientKeyExchange")
+		}
+		ciphertext = ckx.ciphertext[2:]
+	}
+
+	err = rsa.DecryptPKCS1v15SessionKey(config.rand(), cert.PrivateKey.(*rsa.PrivateKey), ciphertext, preMasterSecret)
+	if err != nil {
+		return nil, err
+	}
+	// We don't check the version number in the premaster secret.  For one,
+	// by checking it, we would leak information about the validity of the
+	// encrypted pre-master secret. Secondly, it provides only a small
+	// benefit against a downgrade attack and some implementations send the
+	// wrong version anyway. See the discussion at the end of section
+	// 7.4.7.1 of RFC 4346.
+	return preMasterSecret, nil
+}
+
+func (ka rsaKeyAgreement) processServerKeyExchange(config *Config, clientHello *clientHelloMsg, serverHello *serverHelloMsg, cert *x509.Certificate, skx *serverKeyExchangeMsg) error {
+	return errors.New("unexpected ServerKeyExchange")
+}
+
+func (ka rsaKeyAgreement) generateClientKeyExchange(config *Config, clientHello *clientHelloMsg, cert *x509.Certificate) ([]byte, *clientKeyExchangeMsg, error) {
+	preMasterSecret := make([]byte, 48)
+	preMasterSecret[0] = byte(clientHello.vers >> 8)
+	preMasterSecret[1] = byte(clientHello.vers)
+	_, err := io.ReadFull(config.rand(), preMasterSecret[2:])
+	if err != nil {
+		return nil, nil, err
+	}
+
+	encrypted, err := rsa.EncryptPKCS1v15(config.rand(), cert.PublicKey.(*rsa.PublicKey), preMasterSecret)
+	if err != nil {
+		return nil, nil, err
+	}
+	ckx := new(clientKeyExchangeMsg)
+	ckx.ciphertext = make([]byte, len(encrypted)+2)
+	ckx.ciphertext[0] = byte(len(encrypted) >> 8)
+	ckx.ciphertext[1] = byte(len(encrypted))
+	copy(ckx.ciphertext[2:], encrypted)
+	return preMasterSecret, ckx, nil
+}
+
+// sha1Hash calculates a SHA1 hash over the given byte slices.
+func sha1Hash(slices [][]byte) []byte {
+	hsha1 := sha1.New()
+	for _, slice := range slices {
+		hsha1.Write(slice)
+	}
+	return hsha1.Sum(nil)
+}
+
+// md5SHA1Hash implements TLS 1.0's hybrid hash function which consists of the
+// concatenation of an MD5 and SHA1 hash.
+func md5SHA1Hash(slices [][]byte) []byte {
+	md5sha1 := make([]byte, md5.Size+sha1.Size)
+	hmd5 := md5.New()
+	for _, slice := range slices {
+		hmd5.Write(slice)
+	}
+	copy(md5sha1, hmd5.Sum(nil))
+	copy(md5sha1[md5.Size:], sha1Hash(slices))
+	return md5sha1
+}
+
+// sha256Hash implements TLS 1.2's hash function.
+func sha256Hash(slices [][]byte) []byte {
+	h := sha256.New()
+	for _, slice := range slices {
+		h.Write(slice)
+	}
+	return h.Sum(nil)
+}
+
+// hashForServerKeyExchange hashes the given slices and returns their digest
+// and the identifier of the hash function used. The hashFunc argument is only
+// used for >= TLS 1.2 and precisely identifies the hash function to use.
+func hashForServerKeyExchange(sigType, hashFunc uint8, version uint16, slices ...[]byte) ([]byte, crypto.Hash, error) {
+	if version >= VersionTLS12 {
+		switch hashFunc {
+		case hashSHA256:
+			return sha256Hash(slices), crypto.SHA256, nil
+		case hashSHA1:
+			return sha1Hash(slices), crypto.SHA1, nil
+		default:
+			return nil, crypto.Hash(0), errors.New("tls: unknown hash function used by peer")
+		}
+	}
+	if sigType == signatureECDSA {
+		return sha1Hash(slices), crypto.SHA1, nil
+	}
+	return md5SHA1Hash(slices), crypto.MD5SHA1, nil
+}
+
+// pickTLS12HashForSignature returns a TLS 1.2 hash identifier for signing a
+// ServerKeyExchange given the signature type being used and the client's
+// advertized list of supported signature and hash combinations.
+func pickTLS12HashForSignature(sigType uint8, clientSignatureAndHashes []signatureAndHash) (uint8, error) {
+	if len(clientSignatureAndHashes) == 0 {
+		// If the client didn't specify any signature_algorithms
+		// extension then we can assume that it supports SHA1. See
+		// http://tools.ietf.org/html/rfc5246#section-7.4.1.4.1
+		return hashSHA1, nil
+	}
+
+	for _, sigAndHash := range clientSignatureAndHashes {
+		if sigAndHash.signature != sigType {
+			continue
+		}
+		switch sigAndHash.hash {
+		case hashSHA1, hashSHA256:
+			return sigAndHash.hash, nil
+		}
+	}
+
+	return 0, errors.New("tls: client doesn't support any common hash functions")
+}
+
+// ecdheRSAKeyAgreement implements a TLS key agreement where the server
+// generates a ephemeral EC public/private key pair and signs it. The
+// pre-master secret is then calculated using ECDH. The signature may
+// either be ECDSA or RSA.
+type ecdheKeyAgreement struct {
+	version    uint16
+	sigType    uint8
+	privateKey []byte
+	curve      elliptic.Curve
+	x, y       *big.Int
+}
+
+func (ka *ecdheKeyAgreement) generateServerKeyExchange(config *Config, cert *Certificate, clientHello *clientHelloMsg, hello *serverHelloMsg) (*serverKeyExchangeMsg, error) {
+	var curveid uint16
+
+Curve:
+	for _, c := range clientHello.supportedCurves {
+		switch c {
+		case curveP256:
+			ka.curve = elliptic.P256()
+			curveid = c
+			break Curve
+		case curveP384:
+			ka.curve = elliptic.P384()
+			curveid = c
+			break Curve
+		case curveP521:
+			ka.curve = elliptic.P521()
+			curveid = c
+			break Curve
+		}
+	}
+
+	if curveid == 0 {
+		return nil, errors.New("tls: no supported elliptic curves offered")
+	}
+
+	var x, y *big.Int
+	var err error
+	ka.privateKey, x, y, err = elliptic.GenerateKey(ka.curve, config.rand())
+	if err != nil {
+		return nil, err
+	}
+	ecdhePublic := elliptic.Marshal(ka.curve, x, y)
+
+	// http://tools.ietf.org/html/rfc4492#section-5.4
+	serverECDHParams := make([]byte, 1+2+1+len(ecdhePublic))
+	serverECDHParams[0] = 3 // named curve
+	serverECDHParams[1] = byte(curveid >> 8)
+	serverECDHParams[2] = byte(curveid)
+	serverECDHParams[3] = byte(len(ecdhePublic))
+	copy(serverECDHParams[4:], ecdhePublic)
+
+	var tls12HashId uint8
+	if ka.version >= VersionTLS12 {
+		if tls12HashId, err = pickTLS12HashForSignature(ka.sigType, clientHello.signatureAndHashes); err != nil {
+			return nil, err
+		}
+	}
+
+	digest, hashFunc, err := hashForServerKeyExchange(ka.sigType, tls12HashId, ka.version, clientHello.random, hello.random, serverECDHParams)
+	if err != nil {
+		return nil, err
+	}
+	var sig []byte
+	switch ka.sigType {
+	case signatureECDSA:
+		privKey, ok := cert.PrivateKey.(*ecdsa.PrivateKey)
+		if !ok {
+			return nil, errors.New("ECDHE ECDSA requires an ECDSA server private key")
+		}
+		r, s, err := ecdsa.Sign(config.rand(), privKey, digest)
+		if err != nil {
+			return nil, errors.New("failed to sign ECDHE parameters: " + err.Error())
+		}
+		sig, err = asn1.Marshal(ecdsaSignature{r, s})
+	case signatureRSA:
+		privKey, ok := cert.PrivateKey.(*rsa.PrivateKey)
+		if !ok {
+			return nil, errors.New("ECDHE RSA requires a RSA server private key")
+		}
+		sig, err = rsa.SignPKCS1v15(config.rand(), privKey, hashFunc, digest)
+		if err != nil {
+			return nil, errors.New("failed to sign ECDHE parameters: " + err.Error())
+		}
+	default:
+		return nil, errors.New("unknown ECDHE signature algorithm")
+	}
+
+	skx := new(serverKeyExchangeMsg)
+	sigAndHashLen := 0
+	if ka.version >= VersionTLS12 {
+		sigAndHashLen = 2
+	}
+	skx.key = make([]byte, len(serverECDHParams)+sigAndHashLen+2+len(sig))
+	copy(skx.key, serverECDHParams)
+	k := skx.key[len(serverECDHParams):]
+	if ka.version >= VersionTLS12 {
+		k[0] = tls12HashId
+		k[1] = ka.sigType
+		k = k[2:]
+	}
+	k[0] = byte(len(sig) >> 8)
+	k[1] = byte(len(sig))
+	copy(k[2:], sig)
+
+	return skx, nil
+}
+
+func (ka *ecdheKeyAgreement) processClientKeyExchange(config *Config, cert *Certificate, ckx *clientKeyExchangeMsg, version uint16) ([]byte, error) {
+	if len(ckx.ciphertext) == 0 || int(ckx.ciphertext[0]) != len(ckx.ciphertext)-1 {
+		return nil, errors.New("bad ClientKeyExchange")
+	}
+	x, y := elliptic.Unmarshal(ka.curve, ckx.ciphertext[1:])
+	if x == nil {
+		return nil, errors.New("bad ClientKeyExchange")
+	}
+	x, _ = ka.curve.ScalarMult(x, y, ka.privateKey)
+	preMasterSecret := make([]byte, (ka.curve.Params().BitSize+7)>>3)
+	xBytes := x.Bytes()
+	copy(preMasterSecret[len(preMasterSecret)-len(xBytes):], xBytes)
+
+	return preMasterSecret, nil
+}
+
+var errServerKeyExchange = errors.New("invalid ServerKeyExchange")
+
+func (ka *ecdheKeyAgreement) processServerKeyExchange(config *Config, clientHello *clientHelloMsg, serverHello *serverHelloMsg, cert *x509.Certificate, skx *serverKeyExchangeMsg) error {
+	if len(skx.key) < 4 {
+		return errServerKeyExchange
+	}
+	if skx.key[0] != 3 { // named curve
+		return errors.New("server selected unsupported curve")
+	}
+	curveid := uint16(skx.key[1])<<8 | uint16(skx.key[2])
+
+	switch curveid {
+	case curveP256:
+		ka.curve = elliptic.P256()
+	case curveP384:
+		ka.curve = elliptic.P384()
+	case curveP521:
+		ka.curve = elliptic.P521()
+	default:
+		return errors.New("server selected unsupported curve")
+	}
+
+	publicLen := int(skx.key[3])
+	if publicLen+4 > len(skx.key) {
+		return errServerKeyExchange
+	}
+	ka.x, ka.y = elliptic.Unmarshal(ka.curve, skx.key[4:4+publicLen])
+	if ka.x == nil {
+		return errServerKeyExchange
+	}
+	serverECDHParams := skx.key[:4+publicLen]
+
+	sig := skx.key[4+publicLen:]
+	if len(sig) < 2 {
+		return errServerKeyExchange
+	}
+
+	var tls12HashId uint8
+	if ka.version >= VersionTLS12 {
+		// handle SignatureAndHashAlgorithm
+		var sigAndHash []uint8
+		sigAndHash, sig = sig[:2], sig[2:]
+		if sigAndHash[1] != ka.sigType {
+			return errServerKeyExchange
+		}
+		tls12HashId = sigAndHash[0]
+		if len(sig) < 2 {
+			return errServerKeyExchange
+		}
+	}
+	sigLen := int(sig[0])<<8 | int(sig[1])
+	if sigLen+2 != len(sig) {
+		return errServerKeyExchange
+	}
+	sig = sig[2:]
+
+	digest, hashFunc, err := hashForServerKeyExchange(ka.sigType, tls12HashId, ka.version, clientHello.random, serverHello.random, serverECDHParams)
+	if err != nil {
+		return err
+	}
+	switch ka.sigType {
+	case signatureECDSA:
+		pubKey, ok := cert.PublicKey.(*ecdsa.PublicKey)
+		if !ok {
+			return errors.New("ECDHE ECDSA requires a ECDSA server public key")
+		}
+		ecdsaSig := new(ecdsaSignature)
+		if _, err := asn1.Unmarshal(sig, ecdsaSig); err != nil {
+			return err
+		}
+		if ecdsaSig.R.Sign() <= 0 || ecdsaSig.S.Sign() <= 0 {
+			return errors.New("ECDSA signature contained zero or negative values")
+		}
+		if !ecdsa.Verify(pubKey, digest, ecdsaSig.R, ecdsaSig.S) {
+			return errors.New("ECDSA verification failure")
+		}
+	case signatureRSA:
+		pubKey, ok := cert.PublicKey.(*rsa.PublicKey)
+		if !ok {
+			return errors.New("ECDHE RSA requires a RSA server public key")
+		}
+		if err := rsa.VerifyPKCS1v15(pubKey, hashFunc, digest, sig); err != nil {
+			return err
+		}
+	default:
+		return errors.New("unknown ECDHE signature algorithm")
+	}
+
+	return nil
+}
+
+func (ka *ecdheKeyAgreement) generateClientKeyExchange(config *Config, clientHello *clientHelloMsg, cert *x509.Certificate) ([]byte, *clientKeyExchangeMsg, error) {
+	if ka.curve == nil {
+		return nil, nil, errors.New("missing ServerKeyExchange message")
+	}
+	priv, mx, my, err := elliptic.GenerateKey(ka.curve, config.rand())
+	if err != nil {
+		return nil, nil, err
+	}
+	x, _ := ka.curve.ScalarMult(ka.x, ka.y, priv)
+	preMasterSecret := make([]byte, (ka.curve.Params().BitSize+7)>>3)
+	xBytes := x.Bytes()
+	copy(preMasterSecret[len(preMasterSecret)-len(xBytes):], xBytes)
+
+	serialized := elliptic.Marshal(ka.curve, mx, my)
+
+	ckx := new(clientKeyExchangeMsg)
+	ckx.ciphertext = make([]byte, 1+len(serialized))
+	ckx.ciphertext[0] = byte(len(serialized))
+	copy(ckx.ciphertext[1:], serialized)
+
+	return preMasterSecret, ckx, nil
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/prf.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/prf.go
new file mode 100644
index 000000000..fb8b3ab4d
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/prf.go
@@ -0,0 +1,291 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package tls
+
+import (
+	"crypto"
+	"crypto/hmac"
+	"crypto/md5"
+	"crypto/sha1"
+	"crypto/sha256"
+	"hash"
+)
+
+// Split a premaster secret in two as specified in RFC 4346, section 5.
+func splitPreMasterSecret(secret []byte) (s1, s2 []byte) {
+	s1 = secret[0 : (len(secret)+1)/2]
+	s2 = secret[len(secret)/2:]
+	return
+}
+
+// pHash implements the P_hash function, as defined in RFC 4346, section 5.
+func pHash(result, secret, seed []byte, hash func() hash.Hash) {
+	h := hmac.New(hash, secret)
+	h.Write(seed)
+	a := h.Sum(nil)
+
+	j := 0
+	for j < len(result) {
+		h.Reset()
+		h.Write(a)
+		h.Write(seed)
+		b := h.Sum(nil)
+		todo := len(b)
+		if j+todo > len(result) {
+			todo = len(result) - j
+		}
+		copy(result[j:j+todo], b)
+		j += todo
+
+		h.Reset()
+		h.Write(a)
+		a = h.Sum(nil)
+	}
+}
+
+// prf10 implements the TLS 1.0 pseudo-random function, as defined in RFC 2246, section 5.
+func prf10(result, secret, label, seed []byte) {
+	hashSHA1 := sha1.New
+	hashMD5 := md5.New
+
+	labelAndSeed := make([]byte, len(label)+len(seed))
+	copy(labelAndSeed, label)
+	copy(labelAndSeed[len(label):], seed)
+
+	s1, s2 := splitPreMasterSecret(secret)
+	pHash(result, s1, labelAndSeed, hashMD5)
+	result2 := make([]byte, len(result))
+	pHash(result2, s2, labelAndSeed, hashSHA1)
+
+	for i, b := range result2 {
+		result[i] ^= b
+	}
+}
+
+// prf12 implements the TLS 1.2 pseudo-random function, as defined in RFC 5246, section 5.
+func prf12(result, secret, label, seed []byte) {
+	labelAndSeed := make([]byte, len(label)+len(seed))
+	copy(labelAndSeed, label)
+	copy(labelAndSeed[len(label):], seed)
+
+	pHash(result, secret, labelAndSeed, sha256.New)
+}
+
+// prf30 implements the SSL 3.0 pseudo-random function, as defined in
+// www.mozilla.org/projects/security/pki/nss/ssl/draft302.txt section 6.
+func prf30(result, secret, label, seed []byte) {
+	hashSHA1 := sha1.New()
+	hashMD5 := md5.New()
+
+	done := 0
+	i := 0
+	// RFC5246 section 6.3 says that the largest PRF output needed is 128
+	// bytes. Since no more ciphersuites will be added to SSLv3, this will
+	// remain true. Each iteration gives us 16 bytes so 10 iterations will
+	// be sufficient.
+	var b [11]byte
+	for done < len(result) {
+		for j := 0; j <= i; j++ {
+			b[j] = 'A' + byte(i)
+		}
+
+		hashSHA1.Reset()
+		hashSHA1.Write(b[:i+1])
+		hashSHA1.Write(secret)
+		hashSHA1.Write(seed)
+		digest := hashSHA1.Sum(nil)
+
+		hashMD5.Reset()
+		hashMD5.Write(secret)
+		hashMD5.Write(digest)
+
+		done += copy(result[done:], hashMD5.Sum(nil))
+		i++
+	}
+}
+
+const (
+	tlsRandomLength      = 32 // Length of a random nonce in TLS 1.1.
+	masterSecretLength   = 48 // Length of a master secret in TLS 1.1.
+	finishedVerifyLength = 12 // Length of verify_data in a Finished message.
+)
+
+var masterSecretLabel = []byte("master secret")
+var keyExpansionLabel = []byte("key expansion")
+var clientFinishedLabel = []byte("client finished")
+var serverFinishedLabel = []byte("server finished")
+
+func prfForVersion(version uint16) func(result, secret, label, seed []byte) {
+	switch version {
+	case VersionSSL30:
+		return prf30
+	case VersionTLS10, VersionTLS11:
+		return prf10
+	case VersionTLS12:
+		return prf12
+	default:
+		panic("unknown version")
+	}
+}
+
+// masterFromPreMasterSecret generates the master secret from the pre-master
+// secret. See http://tools.ietf.org/html/rfc5246#section-8.1
+func masterFromPreMasterSecret(version uint16, preMasterSecret, clientRandom, serverRandom []byte) []byte {
+	var seed [tlsRandomLength * 2]byte
+	copy(seed[0:len(clientRandom)], clientRandom)
+	copy(seed[len(clientRandom):], serverRandom)
+	masterSecret := make([]byte, masterSecretLength)
+	prfForVersion(version)(masterSecret, preMasterSecret, masterSecretLabel, seed[0:])
+	return masterSecret
+}
+
+// keysFromMasterSecret generates the connection keys from the master
+// secret, given the lengths of the MAC key, cipher key and IV, as defined in
+// RFC 2246, section 6.3.
+func keysFromMasterSecret(version uint16, masterSecret, clientRandom, serverRandom []byte, macLen, keyLen, ivLen int) (clientMAC, serverMAC, clientKey, serverKey, clientIV, serverIV []byte) {
+	var seed [tlsRandomLength * 2]byte
+	copy(seed[0:len(clientRandom)], serverRandom)
+	copy(seed[len(serverRandom):], clientRandom)
+
+	n := 2*macLen + 2*keyLen + 2*ivLen
+	keyMaterial := make([]byte, n)
+	prfForVersion(version)(keyMaterial, masterSecret, keyExpansionLabel, seed[0:])
+	clientMAC = keyMaterial[:macLen]
+	keyMaterial = keyMaterial[macLen:]
+	serverMAC = keyMaterial[:macLen]
+	keyMaterial = keyMaterial[macLen:]
+	clientKey = keyMaterial[:keyLen]
+	keyMaterial = keyMaterial[keyLen:]
+	serverKey = keyMaterial[:keyLen]
+	keyMaterial = keyMaterial[keyLen:]
+	clientIV = keyMaterial[:ivLen]
+	keyMaterial = keyMaterial[ivLen:]
+	serverIV = keyMaterial[:ivLen]
+	return
+}
+
+func newFinishedHash(version uint16) finishedHash {
+	if version >= VersionTLS12 {
+		return finishedHash{sha256.New(), sha256.New(), nil, nil, version}
+	}
+	return finishedHash{sha1.New(), sha1.New(), md5.New(), md5.New(), version}
+}
+
+// A finishedHash calculates the hash of a set of handshake messages suitable
+// for including in a Finished message.
+type finishedHash struct {
+	client hash.Hash
+	server hash.Hash
+
+	// Prior to TLS 1.2, an additional MD5 hash is required.
+	clientMD5 hash.Hash
+	serverMD5 hash.Hash
+
+	version uint16
+}
+
+func (h finishedHash) Write(msg []byte) (n int, err error) {
+	h.client.Write(msg)
+	h.server.Write(msg)
+
+	if h.version < VersionTLS12 {
+		h.clientMD5.Write(msg)
+		h.serverMD5.Write(msg)
+	}
+	return len(msg), nil
+}
+
+// finishedSum30 calculates the contents of the verify_data member of a SSLv3
+// Finished message given the MD5 and SHA1 hashes of a set of handshake
+// messages.
+func finishedSum30(md5, sha1 hash.Hash, masterSecret []byte, magic [4]byte) []byte {
+	md5.Write(magic[:])
+	md5.Write(masterSecret)
+	md5.Write(ssl30Pad1[:])
+	md5Digest := md5.Sum(nil)
+
+	md5.Reset()
+	md5.Write(masterSecret)
+	md5.Write(ssl30Pad2[:])
+	md5.Write(md5Digest)
+	md5Digest = md5.Sum(nil)
+
+	sha1.Write(magic[:])
+	sha1.Write(masterSecret)
+	sha1.Write(ssl30Pad1[:40])
+	sha1Digest := sha1.Sum(nil)
+
+	sha1.Reset()
+	sha1.Write(masterSecret)
+	sha1.Write(ssl30Pad2[:40])
+	sha1.Write(sha1Digest)
+	sha1Digest = sha1.Sum(nil)
+
+	ret := make([]byte, len(md5Digest)+len(sha1Digest))
+	copy(ret, md5Digest)
+	copy(ret[len(md5Digest):], sha1Digest)
+	return ret
+}
+
+var ssl3ClientFinishedMagic = [4]byte{0x43, 0x4c, 0x4e, 0x54}
+var ssl3ServerFinishedMagic = [4]byte{0x53, 0x52, 0x56, 0x52}
+
+// clientSum returns the contents of the verify_data member of a client's
+// Finished message.
+func (h finishedHash) clientSum(masterSecret []byte) []byte {
+	if h.version == VersionSSL30 {
+		return finishedSum30(h.clientMD5, h.client, masterSecret, ssl3ClientFinishedMagic)
+	}
+
+	out := make([]byte, finishedVerifyLength)
+	if h.version >= VersionTLS12 {
+		seed := h.client.Sum(nil)
+		prf12(out, masterSecret, clientFinishedLabel, seed)
+	} else {
+		seed := make([]byte, 0, md5.Size+sha1.Size)
+		seed = h.clientMD5.Sum(seed)
+		seed = h.client.Sum(seed)
+		prf10(out, masterSecret, clientFinishedLabel, seed)
+	}
+	return out
+}
+
+// serverSum returns the contents of the verify_data member of a server's
+// Finished message.
+func (h finishedHash) serverSum(masterSecret []byte) []byte {
+	if h.version == VersionSSL30 {
+		return finishedSum30(h.serverMD5, h.server, masterSecret, ssl3ServerFinishedMagic)
+	}
+
+	out := make([]byte, finishedVerifyLength)
+	if h.version >= VersionTLS12 {
+		seed := h.server.Sum(nil)
+		prf12(out, masterSecret, serverFinishedLabel, seed)
+	} else {
+		seed := make([]byte, 0, md5.Size+sha1.Size)
+		seed = h.serverMD5.Sum(seed)
+		seed = h.server.Sum(seed)
+		prf10(out, masterSecret, serverFinishedLabel, seed)
+	}
+	return out
+}
+
+// hashForClientCertificate returns a digest, hash function, and TLS 1.2 hash
+// id suitable for signing by a TLS client certificate.
+func (h finishedHash) hashForClientCertificate(sigType uint8) ([]byte, crypto.Hash, uint8) {
+	if h.version >= VersionTLS12 {
+		digest := h.server.Sum(nil)
+		return digest, crypto.SHA256, hashSHA256
+	}
+	if sigType == signatureECDSA {
+		digest := h.server.Sum(nil)
+		return digest, crypto.SHA1, hashSHA1
+	}
+
+	digest := make([]byte, 0, 36)
+	digest = h.serverMD5.Sum(digest)
+	digest = h.server.Sum(digest)
+	return digest, crypto.MD5SHA1, 0 /* not specified in TLS 1.2. */
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/ticket.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/ticket.go
new file mode 100644
index 000000000..4cfc5a53f
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/ticket.go
@@ -0,0 +1,182 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package tls
+
+import (
+	"bytes"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/hmac"
+	"crypto/sha256"
+	"crypto/subtle"
+	"errors"
+	"io"
+)
+
+// sessionState contains the information that is serialized into a session
+// ticket in order to later resume a connection.
+type sessionState struct {
+	vers         uint16
+	cipherSuite  uint16
+	masterSecret []byte
+	certificates [][]byte
+}
+
+func (s *sessionState) equal(i interface{}) bool {
+	s1, ok := i.(*sessionState)
+	if !ok {
+		return false
+	}
+
+	if s.vers != s1.vers ||
+		s.cipherSuite != s1.cipherSuite ||
+		!bytes.Equal(s.masterSecret, s1.masterSecret) {
+		return false
+	}
+
+	if len(s.certificates) != len(s1.certificates) {
+		return false
+	}
+
+	for i := range s.certificates {
+		if !bytes.Equal(s.certificates[i], s1.certificates[i]) {
+			return false
+		}
+	}
+
+	return true
+}
+
+func (s *sessionState) marshal() []byte {
+	length := 2 + 2 + 2 + len(s.masterSecret) + 2
+	for _, cert := range s.certificates {
+		length += 4 + len(cert)
+	}
+
+	ret := make([]byte, length)
+	x := ret
+	x[0] = byte(s.vers >> 8)
+	x[1] = byte(s.vers)
+	x[2] = byte(s.cipherSuite >> 8)
+	x[3] = byte(s.cipherSuite)
+	x[4] = byte(len(s.masterSecret) >> 8)
+	x[5] = byte(len(s.masterSecret))
+	x = x[6:]
+	copy(x, s.masterSecret)
+	x = x[len(s.masterSecret):]
+
+	x[0] = byte(len(s.certificates) >> 8)
+	x[1] = byte(len(s.certificates))
+	x = x[2:]
+
+	for _, cert := range s.certificates {
+		x[0] = byte(len(cert) >> 24)
+		x[1] = byte(len(cert) >> 16)
+		x[2] = byte(len(cert) >> 8)
+		x[3] = byte(len(cert))
+		copy(x[4:], cert)
+		x = x[4+len(cert):]
+	}
+
+	return ret
+}
+
+func (s *sessionState) unmarshal(data []byte) bool {
+	if len(data) < 8 {
+		return false
+	}
+
+	s.vers = uint16(data[0])<<8 | uint16(data[1])
+	s.cipherSuite = uint16(data[2])<<8 | uint16(data[3])
+	masterSecretLen := int(data[4])<<8 | int(data[5])
+	data = data[6:]
+	if len(data) < masterSecretLen {
+		return false
+	}
+
+	s.masterSecret = data[:masterSecretLen]
+	data = data[masterSecretLen:]
+
+	if len(data) < 2 {
+		return false
+	}
+
+	numCerts := int(data[0])<<8 | int(data[1])
+	data = data[2:]
+
+	s.certificates = make([][]byte, numCerts)
+	for i := range s.certificates {
+		if len(data) < 4 {
+			return false
+		}
+		certLen := int(data[0])<<24 | int(data[1])<<16 | int(data[2])<<8 | int(data[3])
+		data = data[4:]
+		if certLen < 0 {
+			return false
+		}
+		if len(data) < certLen {
+			return false
+		}
+		s.certificates[i] = data[:certLen]
+		data = data[certLen:]
+	}
+
+	if len(data) > 0 {
+		return false
+	}
+
+	return true
+}
+
+func (c *Conn) encryptTicket(state *sessionState) ([]byte, error) {
+	serialized := state.marshal()
+	encrypted := make([]byte, aes.BlockSize+len(serialized)+sha256.Size)
+	iv := encrypted[:aes.BlockSize]
+	macBytes := encrypted[len(encrypted)-sha256.Size:]
+
+	if _, err := io.ReadFull(c.config.rand(), iv); err != nil {
+		return nil, err
+	}
+	block, err := aes.NewCipher(c.config.SessionTicketKey[:16])
+	if err != nil {
+		return nil, errors.New("tls: failed to create cipher while encrypting ticket: " + err.Error())
+	}
+	cipher.NewCTR(block, iv).XORKeyStream(encrypted[aes.BlockSize:], serialized)
+
+	mac := hmac.New(sha256.New, c.config.SessionTicketKey[16:32])
+	mac.Write(encrypted[:len(encrypted)-sha256.Size])
+	mac.Sum(macBytes[:0])
+
+	return encrypted, nil
+}
+
+func (c *Conn) decryptTicket(encrypted []byte) (*sessionState, bool) {
+	if len(encrypted) < aes.BlockSize+sha256.Size {
+		return nil, false
+	}
+
+	iv := encrypted[:aes.BlockSize]
+	macBytes := encrypted[len(encrypted)-sha256.Size:]
+
+	mac := hmac.New(sha256.New, c.config.SessionTicketKey[16:32])
+	mac.Write(encrypted[:len(encrypted)-sha256.Size])
+	expected := mac.Sum(nil)
+
+	if subtle.ConstantTimeCompare(macBytes, expected) != 1 {
+		return nil, false
+	}
+
+	block, err := aes.NewCipher(c.config.SessionTicketKey[:16])
+	if err != nil {
+		return nil, false
+	}
+	ciphertext := encrypted[aes.BlockSize : len(encrypted)-sha256.Size]
+	plaintext := ciphertext
+	cipher.NewCTR(block, iv).XORKeyStream(plaintext, ciphertext)
+
+	state := new(sessionState)
+	ok := state.unmarshal(plaintext)
+	return state, ok
+}
diff --git a/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/tls.go b/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/tls.go
new file mode 100644
index 000000000..6c67506fc
--- /dev/null
+++ b/vendor/github.com/masterzen/azure-sdk-for-go/core/tls/tls.go
@@ -0,0 +1,225 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package tls partially implements TLS 1.2, as specified in RFC 5246.
+package tls
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/rsa"
+	"crypto/x509"
+	"encoding/pem"
+	"errors"
+	"io/ioutil"
+	"net"
+	"strings"
+)
+
+// Server returns a new TLS server side connection
+// using conn as the underlying transport.
+// The configuration config must be non-nil and must have
+// at least one certificate.
+func Server(conn net.Conn, config *Config) *Conn {
+	return &Conn{conn: conn, config: config}
+}
+
+// Client returns a new TLS client side connection
+// using conn as the underlying transport.
+// Client interprets a nil configuration as equivalent to
+// the zero configuration; see the documentation of Config
+// for the defaults.
+func Client(conn net.Conn, config *Config) *Conn {
+	return &Conn{conn: conn, config: config, isClient: true}
+}
+
+// A listener implements a network listener (net.Listener) for TLS connections.
+type listener struct {
+	net.Listener
+	config *Config
+}
+
+// Accept waits for and returns the next incoming TLS connection.
+// The returned connection c is a *tls.Conn.
+func (l *listener) Accept() (c net.Conn, err error) {
+	c, err = l.Listener.Accept()
+	if err != nil {
+		return
+	}
+	c = Server(c, l.config)
+	return
+}
+
+// NewListener creates a Listener which accepts connections from an inner
+// Listener and wraps each connection with Server.
+// The configuration config must be non-nil and must have
+// at least one certificate.
+func NewListener(inner net.Listener, config *Config) net.Listener {
+	l := new(listener)
+	l.Listener = inner
+	l.config = config
+	return l
+}
+
+// Listen creates a TLS listener accepting connections on the
+// given network address using net.Listen.
+// The configuration config must be non-nil and must have
+// at least one certificate.
+func Listen(network, laddr string, config *Config) (net.Listener, error) {
+	if config == nil || len(config.Certificates) == 0 {
+		return nil, errors.New("tls.Listen: no certificates in configuration")
+	}
+	l, err := net.Listen(network, laddr)
+	if err != nil {
+		return nil, err
+	}
+	return NewListener(l, config), nil
+}
+
+// Dial connects to the given network address using net.Dial
+// and then initiates a TLS handshake, returning the resulting
+// TLS connection.
+// Dial interprets a nil configuration as equivalent to
+// the zero configuration; see the documentation of Config
+// for the defaults.
+func Dial(network, addr string, config *Config) (*Conn, error) {
+	raddr := addr
+	c, err := net.Dial(network, raddr)
+	if err != nil {
+		return nil, err
+	}
+
+	colonPos := strings.LastIndex(raddr, ":")
+	if colonPos == -1 {
+		colonPos = len(raddr)
+	}
+	hostname := raddr[:colonPos]
+
+	if config == nil {
+		config = defaultConfig()
+	}
+	// If no ServerName is set, infer the ServerName
+	// from the hostname we're connecting to.
+	if config.ServerName == "" {
+		// Make a copy to avoid polluting argument or default.
+		c := *config
+		c.ServerName = hostname
+		config = &c
+	}
+	conn := Client(c, config)
+	if err = conn.Handshake(); err != nil {
+		c.Close()
+		return nil, err
+	}
+	return conn, nil
+}
+
+// LoadX509KeyPair reads and parses a public/private key pair from a pair of
+// files. The files must contain PEM encoded data.
+func LoadX509KeyPair(certFile, keyFile string) (cert Certificate, err error) {
+	certPEMBlock, err := ioutil.ReadFile(certFile)
+	if err != nil {
+		return
+	}
+	keyPEMBlock, err := ioutil.ReadFile(keyFile)
+	if err != nil {
+		return
+	}
+	return X509KeyPair(certPEMBlock, keyPEMBlock)
+}
+
+// X509KeyPair parses a public/private key pair from a pair of
+// PEM encoded data.
+func X509KeyPair(certPEMBlock, keyPEMBlock []byte) (cert Certificate, err error) {
+	var certDERBlock *pem.Block
+	for {
+		certDERBlock, certPEMBlock = pem.Decode(certPEMBlock)
+		if certDERBlock == nil {
+			break
+		}
+		if certDERBlock.Type == "CERTIFICATE" {
+			cert.Certificate = append(cert.Certificate, certDERBlock.Bytes)
+		}
+	}
+
+	if len(cert.Certificate) == 0 {
+		err = errors.New("crypto/tls: failed to parse certificate PEM data")
+		return
+	}
+
+	var keyDERBlock *pem.Block
+	for {
+		keyDERBlock, keyPEMBlock = pem.Decode(keyPEMBlock)
+		if keyDERBlock == nil {
+			err = errors.New("crypto/tls: failed to parse key PEM data")
+			return
+		}
+		if keyDERBlock.Type == "PRIVATE KEY" || strings.HasSuffix(keyDERBlock.Type, " PRIVATE KEY") {
+			break
+		}
+	}
+
+	cert.PrivateKey, err = parsePrivateKey(keyDERBlock.Bytes)
+	if err != nil {
+		return
+	}
+
+	// We don't need to parse the public key for TLS, but we so do anyway
+	// to check that it looks sane and matches the private key.
+	x509Cert, err := x509.ParseCertificate(cert.Certificate[0])
+	if err != nil {
+		return
+	}
+
+	switch pub := x509Cert.PublicKey.(type) {
+	case *rsa.PublicKey:
+		priv, ok := cert.PrivateKey.(*rsa.PrivateKey)
+		if !ok {
+			err = errors.New("crypto/tls: private key type does not match public key type")
+			return
+		}
+		if pub.N.Cmp(priv.N) != 0 {
+			err = errors.New("crypto/tls: private key does not match public key")
+			return
+		}
+	case *ecdsa.PublicKey:
+		priv, ok := cert.PrivateKey.(*ecdsa.PrivateKey)
+		if !ok {
+			err = errors.New("crypto/tls: private key type does not match public key type")
+			return
+
+		}
+		if pub.X.Cmp(priv.X) != 0 || pub.Y.Cmp(priv.Y) != 0 {
+			err = errors.New("crypto/tls: private key does not match public key")
+			return
+		}
+	default:
+		err = errors.New("crypto/tls: unknown public key algorithm")
+		return
+	}
+
+	return
+}
+
+// Attempt to parse the given private key DER block. OpenSSL 0.9.8 generates
+// PKCS#1 private keys by default, while OpenSSL 1.0.0 generates PKCS#8 keys.
+// OpenSSL ecparam generates SEC1 EC private keys for ECDSA. We try all three.
+func parsePrivateKey(der []byte) (crypto.PrivateKey, error) {
+	if key, err := x509.ParsePKCS1PrivateKey(der); err == nil {
+		return key, nil
+	}
+	if key, err := x509.ParsePKCS8PrivateKey(der); err == nil {
+		switch key := key.(type) {
+		case *rsa.PrivateKey, *ecdsa.PrivateKey:
+			return key, nil
+		default:
+			return nil, errors.New("crypto/tls: found unknown private key type in PKCS#8 wrapping")
+		}
+	}
+	if key, err := x509.ParseECPrivateKey(der); err == nil {
+		return key, nil
+	}
+
+	return nil, errors.New("crypto/tls: failed to parse private key")
+}
diff --git a/vendor/github.com/masterzen/winrm/README.md b/vendor/github.com/masterzen/winrm/README.md
index e2ca879fe..2f1d0ad5c 100644
--- a/vendor/github.com/masterzen/winrm/README.md
+++ b/vendor/github.com/masterzen/winrm/README.md
@@ -65,24 +65,34 @@ For command-line usage check the [winrm-cli project](https://github.com/masterze
 
 **Warning the API might be subject to change.**
 
-For the fast version (this doesn't allow to send input to the command):
+For the fast version (this doesn't allow to send input to the command) and it's using HTTP as the transport:
 
 ```go
-import "github.com/masterzen/winrm/winrm"
+package main
 
-client ,_:= winrm.NewClient(&EndPoint{Host:"localhost",Port:5985,HTTPS:false,Insecure:false,CACert:nil}, "Administrator", "secret")
+import (
+	"github.com/masterzen/winrm"
+	"os"
+)
+
+endpoint := winrm.NewEndpoint(host, 5986, false, false, nil, nil, nil, 0)
+client, err := winrm.NewClient(endpoint, "Administrator", "secret")
+if err != nil {
+	panic(err)
+}
 client.Run("ipconfig /all", os.Stdout, os.Stderr)
 ```
 
 or
 ```go
+package main
 import (
-  "github.com/masterzen/winrm/winrm"
+  "github.com/masterzen/winrm"
   "fmt"
   "os"
 )
 
-endpoint := winrm.NewEndpoint("localhost", 5985, false, false, nil)
+endpoint := winrm.NewEndpoint("localhost", 5985, false, false, nil, nil, nil, 0)
 client, err := winrm.NewClient(endpoint,"Administrator", "secret")
 if err != nil {
 	panic(err)
@@ -95,18 +105,47 @@ if err != nil {
 
 ```
 
+By passing a TransportDecorator in the Parameters struct it is possible to use different Transports (e.g. NTLM)
+
+```go
+package main
+import (
+  "github.com/masterzen/winrm"
+  "fmt"
+  "os"
+)
+
+endpoint := winrm.NewEndpoint("localhost", 5985, false, false, nil, nil, nil, 0)
+
+params := DefaultParameters
+params.TransportDecorator = func() Transporter { return &ClientNTLM{} }
+
+client, err := NewClientWithParameters(endpoint, "test", "test", params)
+if err != nil {
+	panic(err)
+}
+
+_, err := client.RunWithInput("ipconfig", os.Stdout, os.Stderr, os.Stdin)
+if err != nil {
+	panic(err)
+}
+
+```
+
 For a more complex example, it is possible to call the various functions directly:
 
 ```go
+package main
+
 import (
-  "github.com/masterzen/winrm/winrm"
+  "github.com/masterzen/winrm"
   "fmt"
   "bytes"
   "os"
 )
 
 stdin := bytes.NewBufferString("ipconfig /all")
-endpoint := winrm.NewEndpoint("localhost",5985,false,false,nil)
+endpoint := winrm.NewEndpoint("localhost", 5985, false, false,nil, nil, nil, 0)
 client , err := winrm.NewClient(endpoint, "Administrator", "secret")
 if err != nil {
 	panic(err)
@@ -129,18 +168,37 @@ cmd.Wait()
 shell.Close()
 ```
 
-### Pluggable authentication example: Negotiate/NTLM authentication
-Using the winrm.Parameters.TransportDecorator, it is possible to wrap or completely replace the outgoing http.RoundTripper. For example, use github.com/Azure/go-ntlmssp to plug in Negotiate/NTLM authentication :
-
+For using HTTPS authentication with x 509 cert without checking the CA
 ```go
-import (
-  "github.com/masterzen/winrm/winrm"
-  "github.com/Azure/go-ntlmssp"
-)
+	package main
 
-params := winrm.DefaultParameters()
-params.TransportDecorator = func(t *http.Transport) http.RoundTripper { return ntlmssp.Negotiator{t} }
-client, err := winrm.NewClientWithParameters(..., params)
+	import (
+		"github.com/masterzen/winrm"
+		"os"
+		"io/ioutil"
+	)
+
+	clientCert, err := ioutil.ReadFile("path/to/cert")
+	if err != nil {
+		panic(err)
+	}
+
+	clientKey, err := ioutil.ReadFile("path/to/key")
+	if err != nil {
+		panic(err)
+	}
+
+	winrm.DefaultParameters.TransportDecorator = func() winrm.Transporter {
+		// winrm https module
+		return &winrm.ClientAuthRequest{}
+	}
+
+	endpoint := winrm.NewEndpoint(host, 5986, false, false, clientCert, clientKey, nil, 0)
+	client, err := winrm.NewClient(endpoint, "Administrator", ""
+	if err != nil {
+		panic(err)
+	}
+	client.Run("ipconfig /all", os.Stdout, os.Stderr)
 ```
 
 ## Developing on WinRM
@@ -154,7 +212,7 @@ and [Bazaar](http://bazaar.canonical.com/en/) to be installed.
 Winrm itself doesn't require these, but a dependency of a dependency does.
 
 Next, clone this repository into `$GOPATH/src/github.com/masterzen/winrm` and
-then just type `make`. 
+then just type `make`.
 
 You can run tests by typing `make test`.
 
diff --git a/vendor/github.com/masterzen/winrm/auth.go b/vendor/github.com/masterzen/winrm/auth.go
new file mode 100644
index 000000000..93f607631
--- /dev/null
+++ b/vendor/github.com/masterzen/winrm/auth.go
@@ -0,0 +1,99 @@
+package winrm
+
+import (
+	"fmt"
+	"io/ioutil"
+	"strings"
+
+	"github.com/masterzen/azure-sdk-for-go/core/http"
+	"github.com/masterzen/azure-sdk-for-go/core/tls"
+
+	"github.com/masterzen/winrm/soap"
+)
+
+type ClientAuthRequest struct {
+	transport http.RoundTripper
+}
+
+func (c *ClientAuthRequest) Transport(endpoint *Endpoint) error {
+	cert, err := tls.X509KeyPair(endpoint.Cert, endpoint.Key)
+	if err != nil {
+		return err
+	}
+
+	transport := &http.Transport{
+		TLSClientConfig: &tls.Config{
+			InsecureSkipVerify: endpoint.Insecure,
+			Certificates:       []tls.Certificate{cert},
+		},
+		ResponseHeaderTimeout: endpoint.Timeout,
+	}
+
+	if endpoint.CACert != nil && len(endpoint.CACert) > 0 {
+		certPool, err := readCACerts(endpoint.CACert)
+		if err != nil {
+			return err
+		}
+
+		transport.TLSClientConfig.RootCAs = certPool
+	}
+
+	c.transport = transport
+
+	return nil
+}
+
+// parse func reads the response body and return it as a string
+func parse(response *http.Response) (string, error) {
+
+	// if we recived the content we expected
+	if strings.Contains(response.Header.Get("Content-Type"), "application/soap+xml") {
+		body, err := ioutil.ReadAll(response.Body)
+		defer func() {
+			// defer can modify the returned value before
+			// it is actually passed to the calling statement
+			if errClose := response.Body.Close(); errClose != nil && err == nil {
+				err = errClose
+			}
+		}()
+		if err != nil {
+			return "", fmt.Errorf("error while reading request body %s", err)
+		}
+
+		return string(body), nil
+	}
+
+	return "", fmt.Errorf("invalid content type")
+}
+
+func (c ClientAuthRequest) Post(client *Client, request *soap.SoapMessage) (string, error) {
+	httpClient := &http.Client{Transport: c.transport}
+
+	req, err := http.NewRequest("POST", client.url, strings.NewReader(request.String()))
+	if err != nil {
+		return "", fmt.Errorf("impossible to create http request %s", err)
+	}
+
+	req.Header.Set("Content-Type", soapXML+";charset=UTF-8")
+	req.Header.Set("Authorization", "http://schemas.dmtf.org/wbem/wsman/1/wsman/secprofile/https/mutual")
+
+	resp, err := httpClient.Do(req)
+	if err != nil {
+		return "", fmt.Errorf("unknown error %s", err)
+	}
+
+	body, err := parse(resp)
+	if err != nil {
+		return "", fmt.Errorf("http response error: %d - %s", resp.StatusCode, err.Error())
+	}
+
+	// if we have different 200 http status code
+	// we must replace the error
+	defer func() {
+		if resp.StatusCode != 200 {
+			body, err = "", fmt.Errorf("http error %d: %s", resp.StatusCode, body)
+		}
+	}()
+
+	return body, err
+}
diff --git a/vendor/github.com/masterzen/winrm/client.go b/vendor/github.com/masterzen/winrm/client.go
index cbc833c20..03755ff4e 100644
--- a/vendor/github.com/masterzen/winrm/client.go
+++ b/vendor/github.com/masterzen/winrm/client.go
@@ -2,11 +2,9 @@ package winrm
 
 import (
 	"bytes"
-	"crypto/tls"
 	"crypto/x509"
 	"fmt"
 	"io"
-	"net/http"
 
 	"github.com/masterzen/winrm/soap"
 )
@@ -14,12 +12,19 @@ import (
 // Client struct
 type Client struct {
 	Parameters
-	username  string
-	password  string
-	useHTTPS  bool
-	url       string
-	http      HttpPost
-	transport http.RoundTripper
+	username string
+	password string
+	useHTTPS bool
+	url      string
+	http     Transporter
+}
+
+// Transporter does different transporters
+// and init a Post request based on them
+type Transporter interface {
+	// init request baset on the transport configurations
+	Post(*Client, *soap.SoapMessage) (string, error)
+	Transport(*Endpoint) error
 }
 
 // NewClient will create a new remote client on url, connecting with user and password
@@ -31,46 +36,29 @@ func NewClient(endpoint *Endpoint, user, password string) (*Client, error) {
 // NewClientWithParameters will create a new remote client on url, connecting with user and password
 // This function doesn't connect (connection happens only when CreateShell is called)
 func NewClientWithParameters(endpoint *Endpoint, user, password string, params *Parameters) (*Client, error) {
-	transport, err := newTransport(endpoint)
 
+	// alloc a new client
 	client := &Client{
 		Parameters: *params,
 		username:   user,
 		password:   password,
 		url:        endpoint.url(),
-		http:       PostRequest,
 		useHTTPS:   endpoint.HTTPS,
-		transport:  transport,
+		// default transport
+		http: &clientRequest{},
 	}
 
+	// switch to other transport if provided
 	if params.TransportDecorator != nil {
-		client.transport = params.TransportDecorator(transport)
+		client.http = params.TransportDecorator()
 	}
 
-	return client, err
-}
-
-// newTransport will create a new HTTP Transport,
-// with options specified within the endpoint configuration
-func newTransport(endpoint *Endpoint) (*http.Transport, error) {
-
-	transport := &http.Transport{
-		TLSClientConfig: &tls.Config{
-			InsecureSkipVerify: endpoint.Insecure,
-		},
-		ResponseHeaderTimeout: endpoint.Timeout,
+	// set the transport to some endpoint configuration
+	if err := client.http.Transport(endpoint); err != nil {
+		return nil, fmt.Errorf("Can't parse this key and certs: %s", err)
 	}
 
-	if endpoint.CACert != nil && len(endpoint.CACert) > 0 {
-		certPool, err := readCACerts(endpoint.CACert)
-		if err != nil {
-			return nil, err
-		}
-
-		transport.TLSClientConfig.RootCAs = certPool
-	}
-
-	return transport, nil
+	return client, nil
 }
 
 func readCACerts(certs []byte) (*x509.CertPool, error) {
@@ -110,7 +98,7 @@ func (c *Client) NewShell(id string) *Shell {
 
 // sendRequest exec the custom http func from the client
 func (c *Client) sendRequest(request *soap.SoapMessage) (string, error) {
-	return c.http(c, request)
+	return c.http.Post(c, request)
 }
 
 // Run will run command on the the remote host, writing the process stdout and stderr to
@@ -183,4 +171,5 @@ func (c Client) RunWithInput(command string, stdout, stderr io.Writer, stdin io.
 	cmd.Wait()
 
 	return cmd.ExitCode(), cmd.err
+
 }
diff --git a/vendor/github.com/masterzen/winrm/http.go b/vendor/github.com/masterzen/winrm/http.go
index 8b3355cfd..f21871f35 100644
--- a/vendor/github.com/masterzen/winrm/http.go
+++ b/vendor/github.com/masterzen/winrm/http.go
@@ -1,6 +1,7 @@
 package winrm
 
 import (
+	"crypto/tls"
 	"fmt"
 	"io/ioutil"
 	"net/http"
@@ -11,16 +12,19 @@ import (
 
 var soapXML = "application/soap+xml"
 
-// HttpPost type func for handling http requests
-type HttpPost func(*Client, *soap.SoapMessage) (string, error)
-
 // body func reads the response body and return it as a string
 func body(response *http.Response) (string, error) {
 
 	// if we recived the content we expected
 	if strings.Contains(response.Header.Get("Content-Type"), "application/soap+xml") {
 		body, err := ioutil.ReadAll(response.Body)
-		defer response.Body.Close()
+		defer func() {
+			// defer can modify the returned value before
+			// it is actually passed to the calling statement
+			if errClose := response.Body.Close(); errClose != nil && err == nil {
+				err = errClose
+			}
+		}()
 		if err != nil {
 			return "", fmt.Errorf("error while reading request body %s", err)
 		}
@@ -31,9 +35,35 @@ func body(response *http.Response) (string, error) {
 	return "", fmt.Errorf("invalid content type")
 }
 
-// PostRequest make post to the winrm soap service
-func PostRequest(client *Client, request *soap.SoapMessage) (string, error) {
-	httpClient := &http.Client{Transport: client.transport}
+type clientRequest struct {
+	transport http.RoundTripper
+}
+
+func (c *clientRequest) Transport(endpoint *Endpoint) error {
+	transport := &http.Transport{
+		TLSClientConfig: &tls.Config{
+			InsecureSkipVerify: endpoint.Insecure,
+		},
+		ResponseHeaderTimeout: endpoint.Timeout,
+	}
+
+	if endpoint.CACert != nil && len(endpoint.CACert) > 0 {
+		certPool, err := readCACerts(endpoint.CACert)
+		if err != nil {
+			return err
+		}
+
+		transport.TLSClientConfig.RootCAs = certPool
+	}
+
+	c.transport = transport
+
+	return nil
+}
+
+// Post make post to the winrm soap service
+func (c clientRequest) Post(client *Client, request *soap.SoapMessage) (string, error) {
+	httpClient := &http.Client{Transport: c.transport}
 
 	req, err := http.NewRequest("POST", client.url, strings.NewReader(request.String()))
 	if err != nil {
@@ -50,9 +80,14 @@ func PostRequest(client *Client, request *soap.SoapMessage) (string, error) {
 	if err != nil {
 		return "", fmt.Errorf("http response error: %d - %s", resp.StatusCode, err.Error())
 	}
-	if resp.StatusCode != 200 {
-		return "", fmt.Errorf("http error: %d - %s", resp.StatusCode, body)
-	}
+
+	// if we have different 200 http status code
+	// we must replace the error
+	defer func() {
+		if resp.StatusCode != 200 {
+			body, err = "", fmt.Errorf("http error %d: %s", resp.StatusCode, body)
+		}
+	}()
 
 	return body, err
 }
diff --git a/vendor/github.com/masterzen/winrm/ntlm.go b/vendor/github.com/masterzen/winrm/ntlm.go
new file mode 100644
index 000000000..f2ac707a4
--- /dev/null
+++ b/vendor/github.com/masterzen/winrm/ntlm.go
@@ -0,0 +1,23 @@
+package winrm
+
+import (
+	ntlmssp "github.com/Azure/go-ntlmssp"
+	"github.com/masterzen/winrm/soap"
+)
+
+// ClientNTLM provides a transport via NTLMv2
+type ClientNTLM struct {
+	clientRequest
+}
+
+// Transport creates the wrapped NTLM transport
+func (c *ClientNTLM) Transport(endpoint *Endpoint) error {
+	c.clientRequest.Transport(endpoint)
+	c.clientRequest.transport = &ntlmssp.Negotiator{RoundTripper: c.clientRequest.transport}
+	return nil
+}
+
+// Post make post to the winrm soap service (forwarded to clientRequest implementation)
+func (c ClientNTLM) Post(client *Client, request *soap.SoapMessage) (string, error) {
+	return c.clientRequest.Post(client, request)
+}
diff --git a/vendor/github.com/masterzen/winrm/parameters.go b/vendor/github.com/masterzen/winrm/parameters.go
index a9bbf2a9b..eb3771be1 100644
--- a/vendor/github.com/masterzen/winrm/parameters.go
+++ b/vendor/github.com/masterzen/winrm/parameters.go
@@ -1,16 +1,12 @@
 package winrm
 
-import (
-	"net/http"
-)
-
 // Parameters struct defines
 // metadata information and http transport config
 type Parameters struct {
 	Timeout            string
 	Locale             string
 	EnvelopeSize       int
-	TransportDecorator func(*http.Transport) http.RoundTripper
+	TransportDecorator func() Transporter
 }
 
 // DefaultParameters return constant config
diff --git a/vendor/github.com/packer-community/winrmcp/winrmcp/cp.go b/vendor/github.com/packer-community/winrmcp/winrmcp/cp.go
index 18d77c322..3d6a7f5d2 100644
--- a/vendor/github.com/packer-community/winrmcp/winrmcp/cp.go
+++ b/vendor/github.com/packer-community/winrmcp/winrmcp/cp.go
@@ -2,7 +2,6 @@ package winrmcp
 
 import (
 	"encoding/base64"
-	"errors"
 	"fmt"
 	"io"
 	"log"
@@ -16,7 +15,7 @@ import (
 func doCopy(client *winrm.Client, config *Config, in io.Reader, toPath string) error {
 	tempFile, err := tempFileName()
 	if err != nil {
-		return errors.New(fmt.Sprintf("Error generating unique filename: %v", err))
+		return fmt.Errorf("Error generating unique filename: %v", err)
 	}
 	tempPath := "$env:TEMP\\" + tempFile
 
@@ -26,7 +25,7 @@ func doCopy(client *winrm.Client, config *Config, in io.Reader, toPath string) e
 
 	err = uploadContent(client, config.MaxOperationsPerShell, "%TEMP%\\"+tempFile, in)
 	if err != nil {
-		return errors.New(fmt.Sprintf("Error uploading file to %s: %v", tempPath, err))
+		return fmt.Errorf("Error uploading file to %s: %v", tempPath, err)
 	}
 
 	if os.Getenv("WINRMCP_DEBUG") != "" {
@@ -35,7 +34,7 @@ func doCopy(client *winrm.Client, config *Config, in io.Reader, toPath string) e
 
 	err = restoreContent(client, tempPath, toPath)
 	if err != nil {
-		return errors.New(fmt.Sprintf("Error restoring file from %s to %s: %v", tempPath, toPath, err))
+		return fmt.Errorf("Error restoring file from %s to %s: %v", tempPath, toPath, err)
 	}
 
 	if os.Getenv("WINRMCP_DEBUG") != "" {
@@ -44,7 +43,7 @@ func doCopy(client *winrm.Client, config *Config, in io.Reader, toPath string) e
 
 	err = cleanupContent(client, tempPath)
 	if err != nil {
-		return errors.New(fmt.Sprintf("Error removing temporary file %s: %v", tempPath, err))
+		return fmt.Errorf("Error removing temporary file %s: %v", tempPath, err)
 	}
 
 	return nil
@@ -66,7 +65,7 @@ func uploadContent(client *winrm.Client, maxChunks int, filePath string, reader
 func uploadChunks(client *winrm.Client, filePath string, maxChunks int, reader io.Reader) (bool, error) {
 	shell, err := client.CreateShell()
 	if err != nil {
-		return false, errors.New(fmt.Sprintf("Couldn't create shell: %v", err))
+		return false, fmt.Errorf("Couldn't create shell: %v", err)
 	}
 	defer shell.Close()
 
@@ -126,10 +125,20 @@ func restoreContent(client *winrm.Client, fromPath, toPath string) error {
 		}
 
 		if (Test-Path $tmp_file_path) {
-			$base64_lines = Get-Content $tmp_file_path
-			$base64_string = [string]::join("",$base64_lines)
-			$bytes = [System.Convert]::FromBase64String($base64_string) 
-			[System.IO.File]::WriteAllBytes($dest_file_path, $bytes)
+			$reader = [System.IO.File]::OpenText($tmp_file_path)
+			$writer = [System.IO.File]::OpenWrite($dest_file_path)
+			try {
+				for(;;) {
+					$base64_line = $reader.ReadLine()
+					if ($base64_line -eq $null) { break }
+					$bytes = [System.Convert]::FromBase64String($base64_line)
+					$writer.write($bytes, 0, $bytes.Length)
+				}
+			}
+			finally {
+				$reader.Close()
+				$writer.Close()
+			}
 		} else {
 			echo $null > $dest_file_path
 		}
@@ -155,7 +164,7 @@ func restoreContent(client *winrm.Client, fromPath, toPath string) error {
 	wg.Wait()
 
 	if cmd.ExitCode() != 0 {
-		return errors.New(fmt.Sprintf("restore operation returned code=%d", cmd.ExitCode()))
+		return fmt.Errorf("restore operation returned code=%d", cmd.ExitCode())
 	}
 	return nil
 }
@@ -167,7 +176,10 @@ func cleanupContent(client *winrm.Client, filePath string) error {
 	}
 
 	defer shell.Close()
-	cmd, _ := shell.Execute("powershell", "Remove-Item", filePath, "-ErrorAction SilentlyContinue")
+	cmd, err := shell.Execute("powershell", "Remove-Item", filePath, "-ErrorAction SilentlyContinue")
+	if err != nil {
+		return err
+	}
 
 	cmd.Wait()
 	cmd.Close()
@@ -196,7 +208,7 @@ func appendContent(shell *winrm.Shell, filePath, content string) error {
 	wg.Wait()
 
 	if cmd.ExitCode() != 0 {
-		return errors.New(fmt.Sprintf("upload operation returned code=%d", cmd.ExitCode()))
+		return fmt.Errorf("upload operation returned code=%d", cmd.ExitCode())
 	}
 
 	return nil
diff --git a/vendor/github.com/packer-community/winrmcp/winrmcp/endpoint.go b/vendor/github.com/packer-community/winrmcp/winrmcp/endpoint.go
index d26004f39..a39d32159 100644
--- a/vendor/github.com/packer-community/winrmcp/winrmcp/endpoint.go
+++ b/vendor/github.com/packer-community/winrmcp/winrmcp/endpoint.go
@@ -24,7 +24,7 @@ func parseEndpoint(addr string, https bool, insecure bool, caCert []byte, timeou
 	} else {
 		shost, sport, err := net.SplitHostPort(addr)
 		if err != nil {
-			return nil, errors.New(fmt.Sprintf("Couldn't convert \"%s\" to an address.", addr))
+			return nil, fmt.Errorf("Couldn't convert \"%s\" to an address.", addr)
 		}
 		host = shost
 		port, err = strconv.Atoi(sport)
diff --git a/vendor/github.com/packer-community/winrmcp/winrmcp/ls.go b/vendor/github.com/packer-community/winrmcp/winrmcp/ls.go
index 72dcc0423..60dcc0b79 100644
--- a/vendor/github.com/packer-community/winrmcp/winrmcp/ls.go
+++ b/vendor/github.com/packer-community/winrmcp/winrmcp/ls.go
@@ -2,7 +2,6 @@ package winrmcp
 
 import (
 	"encoding/xml"
-	"errors"
 	"fmt"
 	"log"
 	"os"
@@ -23,7 +22,7 @@ func fetchList(client *winrm.Client, remotePath string) ([]FileItem, error) {
 	script := fmt.Sprintf("Get-ChildItem %s", remotePath)
 	stdout, stderr, _, err := client.RunWithString("powershell -Command \""+script+" | ConvertTo-Xml -NoTypeInformation -As String\"", "")
 	if err != nil {
-		return nil, errors.New(fmt.Sprintf("Couldn't execute script %s: %v", script, err))
+		return nil, fmt.Errorf("Couldn't execute script %s: %v", script, err)
 	}
 
 	if stderr != "" {
@@ -36,7 +35,7 @@ func fetchList(client *winrm.Client, remotePath string) ([]FileItem, error) {
 		doc := pslist{}
 		err := xml.Unmarshal([]byte(stdout), &doc)
 		if err != nil {
-			return nil, errors.New(fmt.Sprintf("Couldn't parse results: %v", err))
+			return nil, fmt.Errorf("Couldn't parse results: %v", err)
 		}
 
 		return convertFileItems(doc.Objects), nil
diff --git a/vendor/github.com/packer-community/winrmcp/winrmcp/winrmcp.go b/vendor/github.com/packer-community/winrmcp/winrmcp/winrmcp.go
index a53d3b915..1a5241851 100644
--- a/vendor/github.com/packer-community/winrmcp/winrmcp/winrmcp.go
+++ b/vendor/github.com/packer-community/winrmcp/winrmcp/winrmcp.go
@@ -1,10 +1,8 @@
 package winrmcp
 
 import (
-	"errors"
 	"fmt"
 	"io"
-	"net/http"
 	"os"
 	"path/filepath"
 	"time"
@@ -26,7 +24,7 @@ type Config struct {
 	ConnectTimeout        time.Duration
 	OperationTimeout      time.Duration
 	MaxOperationsPerShell int
-	TransportDecorator    func(*http.Transport) http.RoundTripper
+	TransportDecorator    func() winrm.Transporter
 }
 
 type Auth struct {
@@ -64,13 +62,13 @@ func New(addr string, config *Config) (*Winrmcp, error) {
 func (fs *Winrmcp) Copy(fromPath, toPath string) error {
 	f, err := os.Open(fromPath)
 	if err != nil {
-		return errors.New(fmt.Sprintf("Couldn't read file %s: %v", fromPath, err))
+		return fmt.Errorf("Couldn't read file %s: %v", fromPath, err)
 	}
 
 	defer f.Close()
 	fi, err := f.Stat()
 	if err != nil {
-		return errors.New(fmt.Sprintf("Couldn't stat file %s: %v", fromPath, err))
+		return fmt.Errorf("Couldn't stat file %s: %v", fromPath, err)
 	}
 
 	if !fi.IsDir() {
@@ -117,7 +115,7 @@ func (fw *fileWalker) copyFile(fromPath string, fi os.FileInfo, err error) error
 
 	f, err := os.Open(hostPath)
 	if err != nil {
-		return errors.New(fmt.Sprintf("Couldn't read file %s: %v", fromPath, err))
+		return fmt.Errorf("Couldn't read file %s: %v", fromPath, err)
 	}
 
 	return doCopy(fw.client, fw.config, f, winPath(toPath))
diff --git a/vendor/vendor.json b/vendor/vendor.json
index fe4f36f6b..d0e47b4e2 100644
--- a/vendor/vendor.json
+++ b/vendor/vendor.json
@@ -557,15 +557,28 @@
 			"path": "github.com/kr/fs",
 			"revision": "2788f0dbd16903de03cb8186e5c7d97b69ad387b"
 		},
+		{
+			"checksumSHA1": "t7hEeujQesCSzjZIPcE80XgQ9M0=",
+			"path": "github.com/masterzen/azure-sdk-for-go/core/http",
+			"revision": "ee4f0065d00cd12b542f18f5bc45799e88163b12",
+			"revisionTime": "2016-10-14T13:56:28Z"
+		},
+		{
+			"checksumSHA1": "xJVMikTtYbfI2KqKeUXaO4292JU=",
+			"path": "github.com/masterzen/azure-sdk-for-go/core/tls",
+			"revision": "ee4f0065d00cd12b542f18f5bc45799e88163b12",
+			"revisionTime": "2016-10-14T13:56:28Z"
+		},
 		{
 			"checksumSHA1": "yg57Q4J8Ob0LoYvqDxsWZ6AHffE=",
 			"path": "github.com/masterzen/simplexml/dom",
 			"revision": "95ba30457eb1121fa27753627c774c7cd4e90083"
 		},
 		{
-			"checksumSHA1": "BL8FA9MJQmmQBH5s9wYvhDWFk0Q=",
+			"checksumSHA1": "24M48du3803/HG1uZTo5aQxmPNk=",
 			"path": "github.com/masterzen/winrm",
-			"revision": "ef3efbb97f99fc204bd9c7edf778a0dbd9781baf"
+			"revision": "a6cd420bebdc21d10c97296556295fcb99dd9635",
+			"revisionTime": "2017-01-16T07:57:11Z"
 		},
 		{
 			"checksumSHA1": "KTsgWipT3ennAAtaKxEZairxero=",
@@ -645,9 +658,10 @@
 			"revision": "179d4d0c4d8d407a32af483c2354df1d2c91e6c3"
 		},
 		{
-			"checksumSHA1": "Cfe+Uaa7inbFKsaRuUSaUVh8KJs=",
+			"checksumSHA1": "CeruhvOoHGjNlO+8M7WSUUz1oXA=",
 			"path": "github.com/packer-community/winrmcp/winrmcp",
-			"revision": "7f50d16167d327698b91ccd5363d8691865e2580"
+			"revision": "eda77c146d051992c737322f60a4f690c9538aa1",
+			"revisionTime": "2017-01-17T09:42:35Z"
 		},
 		{
 			"checksumSHA1": "oaXvjFg802gS/wx1bx2gAQwa7XQ=",