builder/virtualbox: support generic hash types [GH-175]

builder/common/download.go

@@ -2,6 +2,7 @@ package common
 
 import (
 	"bytes"
+	"crypto/md5"
 	"encoding/hex"
 	"errors"
 	"fmt"
@@ -46,6 +47,17 @@ type DownloadClient struct {
 	downloader Downloader
 }
 
+// HashForType returns the Hash implementation for the given string
+// type, or nil if the type is not supported.
+func HashForType(t string) hash.Hash {
+	switch t {
+	case "md5":
+		return md5.New()
+	default:
+		return nil
+	}
+}
+
 // NewDownloadClient returns a new DownloadClient for the given
 // configuration.
 func NewDownloadClient(c *DownloadConfig) *DownloadClient {

builder/common/download_test.go

@@ -40,3 +40,22 @@ func TestDownloadClient_VerifyChecksum(t *testing.T) {
 		t.Fatal("didn't verify")
 	}
 }
+
+func TestHashForType(t *testing.T) {
+	if h := HashForType("md5"); h == nil {
+		t.Fatalf("md5 hash is nil")
+	} else {
+		h.Write([]byte("foo"))
+		result := h.Sum(nil)
+
+		expected := "acbd18db4cc2f85cedef654fccc4a4d8"
+		actual := hex.EncodeToString(result)
+		if actual != expected {
+			t.Fatalf("bad hash: %s", actual)
+		}
+	}
+
+	if HashForType("fake") != nil {
+		t.Fatalf("fake hash is not nil")
+	}
+}

builder/virtualbox/builder.go

@@ -38,7 +38,8 @@ type config struct {
 	HTTPDir              string        `mapstructure:"http_directory"`
 	HTTPPortMin          uint          `mapstructure:"http_port_min"`
 	HTTPPortMax          uint          `mapstructure:"http_port_max"`
-	ISOMD5               string        `mapstructure:"iso_md5"`
+	ISOChecksum          string        `mapstructure:"iso_checksum"`
+	ISOChecksumType      string        `mapstructure:"iso_checksum_type"`
 	ISOUrl               string        `mapstructure:"iso_url"`
 	OutputDir            string        `mapstructure:"output_directory"`
 	ShutdownCommand      string        `mapstructure:"shutdown_command"`
@@ -155,10 +156,21 @@ func (b *Builder) Prepare(raws ...interface{}) error {
 		errs = append(errs, errors.New("http_port_min must be less than http_port_max"))
 	}
 
-	if b.config.ISOMD5 == "" {
-		errs = append(errs, errors.New("Due to large file sizes, an iso_md5 is required"))
+	if b.config.ISOChecksum == "" {
+		errs = append(errs, errors.New("Due to large file sizes, an iso_checksum is required"))
 	} else {
-		b.config.ISOMD5 = strings.ToLower(b.config.ISOMD5)
+		b.config.ISOChecksum = strings.ToLower(b.config.ISOChecksum)
+	}
+
+	if b.config.ISOChecksumType == "" {
+		errs = append(errs, errors.New("The iso_checksum_type must be specified."))
+	} else {
+		b.config.ISOChecksumType = strings.ToLower(b.config.ISOChecksumType)
+		if h := common.HashForType(b.config.ISOChecksumType); h == nil {
+			errs = append(
+				errs,
+				fmt.Errorf("Unsupported checksum type: %s", b.config.ISOChecksumType))
+		}
 	}
 
 	if b.config.ISOUrl == "" {

builder/virtualbox/builder_test.go

@@ -10,9 +10,10 @@ import (
 
 func testConfig() map[string]interface{} {
 	return map[string]interface{}{
-		"iso_md5":      "foo",
-		"iso_url":      "http://www.google.com/",
-		"ssh_username": "foo",
+		"iso_checksum":      "foo",
+		"iso_checksum_type": "md5",
+		"iso_url":           "http://www.google.com/",
+		"ssh_username":      "foo",
 
 		packer.BuildNameConfigKey: "foo",
 	}
@@ -283,26 +284,56 @@ func TestBuilderPrepare_InvalidKey(t *testing.T) {
 	}
 }
 
-func TestBuilderPrepare_ISOMD5(t *testing.T) {
+func TestBuilderPrepare_ISOChecksum(t *testing.T) {
 	var b Builder
 	config := testConfig()
 
 	// Test bad
-	config["iso_md5"] = ""
+	config["iso_checksum"] = ""
 	err := b.Prepare(config)
 	if err == nil {
 		t.Fatal("should have error")
 	}
 
 	// Test good
-	config["iso_md5"] = "FOo"
+	config["iso_checksum"] = "FOo"
 	err = b.Prepare(config)
 	if err != nil {
 		t.Fatalf("should not have error: %s", err)
 	}
 
-	if b.config.ISOMD5 != "foo" {
-		t.Fatalf("should've lowercased: %s", b.config.ISOMD5)
+	if b.config.ISOChecksum != "foo" {
+		t.Fatalf("should've lowercased: %s", b.config.ISOChecksum)
+	}
+}
+
+func TestBuilderPrepare_ISOChecksumType(t *testing.T) {
+	var b Builder
+	config := testConfig()
+
+	// Test bad
+	config["iso_checksum_type"] = ""
+	err := b.Prepare(config)
+	if err == nil {
+		t.Fatal("should have error")
+	}
+
+	// Test good
+	config["iso_checksum_type"] = "mD5"
+	err = b.Prepare(config)
+	if err != nil {
+		t.Fatalf("should not have error: %s", err)
+	}
+
+	if b.config.ISOChecksumType != "md5" {
+		t.Fatalf("should've lowercased: %s", b.config.ISOChecksumType)
+	}
+
+	// Test unknown
+	config["iso_checksum_type"] = "fake"
+	err = b.Prepare(config)
+	if err == nil {
+		t.Fatal("should have error")
 	}
 }
 

builder/virtualbox/step_download_iso.go

@@ -1,7 +1,6 @@
 package virtualbox
 
 import (
-	"crypto/md5"
 	"encoding/hex"
 	"fmt"
 	"github.com/mitchellh/multistep"
@@ -33,7 +32,7 @@ func (s *stepDownloadISO) Run(state map[string]interface{}) multistep.StepAction
 	config := state["config"].(*config)
 	ui := state["ui"].(packer.Ui)
 
-	checksum, err := hex.DecodeString(config.ISOMD5)
+	checksum, err := hex.DecodeString(config.ISOChecksum)
 	if err != nil {
 		state["error"] = fmt.Errorf("Error parsing checksum: %s", err)
 		return multistep.ActionHalt
@@ -47,7 +46,7 @@ func (s *stepDownloadISO) Run(state map[string]interface{}) multistep.StepAction
 		Url:        config.ISOUrl,
 		TargetPath: cachePath,
 		CopyFile:   false,
-		Hash:       md5.New(),
+		Hash:       common.HashForType(config.ISOChecksumType),
 		Checksum:   checksum,
 	}