HDFS-2318. Provide authentication to webhdfs using SPNEGO and delegation tokens.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1171611 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -13,6 +13,8 @@ Trunk (unreleased changes)
     HDFS-2338. Add configuration option to enable/disable webhdfs.
     (jitendra via szetszwo)
 
+    HDFS-2318. Provide authentication to webhdfs using SPNEGO.  (szetszwo)
+
   IMPROVEMENTS
 
     HADOOP-7524 Change RPC to allow multiple protocols including multuple versions of the same protocol (sanjay Radia)

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/security/token/delegation/DelegationTokenSecretManager.java

@@ -21,14 +21,20 @@ package org.apache.hadoop.hdfs.security.token.delegation;
 import java.io.DataInputStream;
 import java.io.DataOutputStream;
 import java.io.IOException;
+import java.net.InetSocketAddress;
 import java.util.Iterator;
 
-import org.apache.hadoop.classification.InterfaceAudience;
-import org.apache.hadoop.hdfs.server.namenode.FSNamesystem;
-import org.apache.hadoop.security.token.delegation.AbstractDelegationTokenSecretManager;
-import org.apache.hadoop.security.token.delegation.DelegationKey;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.hdfs.server.namenode.FSNamesystem;
+import org.apache.hadoop.hdfs.server.namenode.NameNode;
+import org.apache.hadoop.io.Text;
+import org.apache.hadoop.security.Credentials;
+import org.apache.hadoop.security.UserGroupInformation;
+import org.apache.hadoop.security.token.Token;
+import org.apache.hadoop.security.token.delegation.AbstractDelegationTokenSecretManager;
+import org.apache.hadoop.security.token.delegation.DelegationKey;
 
 /**
  * A HDFS specific delegation token secret manager.
@@ -278,4 +284,22 @@ public class DelegationTokenSecretManager
       throws IOException {
     namesystem.logUpdateMasterKey(key);
   }
+
+  /** A utility method for creating credentials. */
+  public static Credentials createCredentials(final NameNode namenode,
+      final UserGroupInformation ugi, final String renewer) throws IOException {
+    final Token<DelegationTokenIdentifier> token = namenode.getRpcServer(
+        ).getDelegationToken(new Text(renewer));
+    if (token == null) {
+      throw new IOException("Failed to get the token for " + renewer
+          + ", user=" + ugi.getShortUserName());
+    }
+
+    final InetSocketAddress addr = namenode.getNameNodeAddress();
+    final String s = addr.getAddress().getHostAddress() + ":" + addr.getPort();
+    token.setService(new Text(s));
+    final Credentials c = new Credentials();
+    c.addToken(new Text(ugi.getShortUserName()), token);
+    return c;
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/common/JspHelper.java

@@ -54,6 +54,7 @@ import org.apache.hadoop.hdfs.security.token.block.BlockTokenIdentifier;
 import org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenIdentifier;
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeDescriptor;
 import org.apache.hadoop.hdfs.server.namenode.NameNodeHttpServer;
+import org.apache.hadoop.hdfs.web.resources.UserParam;
 import org.apache.hadoop.http.HtmlQuoting;
 import org.apache.hadoop.io.Text;
 import org.apache.hadoop.net.NetUtils;
@@ -501,29 +502,38 @@ public class JspHelper {
     return null;
   }
 
-  /**
-   * See
-   * {@link JspHelper#getUGI(ServletContext, HttpServletRequest, Configuration)}
-   * , ServletContext is passed as null.
-   */
+  /** Same as getUGI(null, request, conf). */
   public static UserGroupInformation getUGI(HttpServletRequest request,
       Configuration conf) throws IOException {
     return getUGI(null, request, conf);
   }
   
+  /** Same as getUGI(context, request, conf, KERBEROS_SSL, true). */
+  public static UserGroupInformation getUGI(ServletContext context,
+      HttpServletRequest request, Configuration conf) throws IOException {
+    return getUGI(context, request, conf, AuthenticationMethod.KERBEROS_SSL, true);
+  }
+
   /**
    * Get {@link UserGroupInformation} and possibly the delegation token out of
    * the request.
    * @param context the ServletContext that is serving this request.
    * @param request the http request
+   * @param conf configuration
+   * @param secureAuthMethod the AuthenticationMethod used in secure mode.
+   * @param tryUgiParameter Should it try the ugi parameter?
    * @return a new user from the request
    * @throws AccessControlException if the request has no token
    */
   public static UserGroupInformation getUGI(ServletContext context,
-      HttpServletRequest request, Configuration conf) throws IOException {
-    UserGroupInformation ugi = null;
+      HttpServletRequest request, Configuration conf,
+      final AuthenticationMethod secureAuthMethod,
+      final boolean tryUgiParameter) throws IOException {
+    final UserGroupInformation ugi;
+    final String usernameFromQuery = getUsernameFromQuery(request, tryUgiParameter);
+
     if(UserGroupInformation.isSecurityEnabled()) {
-      String user = request.getRemoteUser();
+      final String user = request.getRemoteUser();
       String tokenString = request.getParameter(DELEGATION_PARAMETER_NAME);
       if (tokenString != null) {
         Token<DelegationTokenIdentifier> token = 
@@ -541,6 +551,7 @@ public class JspHelper {
         DelegationTokenIdentifier id = new DelegationTokenIdentifier();
         id.readFields(in);
         ugi = id.getUser();
+        checkUsername(ugi.getUserName(), user);
         ugi.addToken(token);
         ugi.setAuthenticationMethod(AuthenticationMethod.TOKEN);
       } else {
@@ -551,16 +562,15 @@ public class JspHelper {
         ugi = UserGroupInformation.createRemoteUser(user);
         // This is not necessarily true, could have been auth'ed by user-facing
         // filter
-        ugi.setAuthenticationMethod(AuthenticationMethod.KERBEROS_SSL);
+        ugi.setAuthenticationMethod(secureAuthMethod);
       }
-    } else { // Security's not on, pull from url
-      String user = request.getParameter("ugi");
 
-      if(user == null) { // not specified in request
-        ugi = getDefaultWebUser(conf);
-      } else {
-        ugi = UserGroupInformation.createRemoteUser(user.split(",")[0]);
-      }
+      checkUsername(user, usernameFromQuery);
+
+    } else { // Security's not on, pull from url
+      ugi = usernameFromQuery == null?
+          getDefaultWebUser(conf) // not specified in request
+          : UserGroupInformation.createRemoteUser(usernameFromQuery);
       ugi.setAuthenticationMethod(AuthenticationMethod.SIMPLE);
     }
     
@@ -569,6 +579,27 @@ public class JspHelper {
     return ugi;
   }
 
+  private static void checkUsername(final String expected, final String name
+      ) throws IOException {
+    if (name != null && !name.equals(expected)) {
+      throw new IOException("Usernames not matched: name=" + name
+          + " != expected=" + expected);
+    }
+  }
+
+  private static String getUsernameFromQuery(final HttpServletRequest request,
+      final boolean tryUgiParameter) {
+    String username = request.getParameter(UserParam.NAME);
+    if (username == null && tryUgiParameter) {
+      //try ugi parameter
+      final String ugiStr = request.getParameter("ugi");
+      if (ugiStr != null) {
+        username = ugiStr.split(",")[0];
+      }
+    }
+    return username;
+  }
+
   /**
    * Returns the url parameter for the given token string.
    * @param tokenString

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/web/resources/DatanodeWebHdfsMethods.java

@@ -23,6 +23,7 @@ import java.io.OutputStream;
 import java.net.InetSocketAddress;
 import java.net.URI;
 import java.net.URISyntaxException;
+import java.security.PrivilegedExceptionAction;
 import java.util.EnumSet;
 
 import javax.servlet.ServletContext;
@@ -63,6 +64,7 @@ import org.apache.hadoop.hdfs.web.resources.PutOpParam;
 import org.apache.hadoop.hdfs.web.resources.ReplicationParam;
 import org.apache.hadoop.hdfs.web.resources.UriFsPathParam;
 import org.apache.hadoop.io.IOUtils;
+import org.apache.hadoop.security.UserGroupInformation;
 
 /** Web-hdfs DataNode implementation. */
 @Path("")
@@ -78,6 +80,7 @@ public class DatanodeWebHdfsMethods {
   @Produces({MediaType.APPLICATION_JSON})
   public Response put(
       final InputStream in,
+      @Context final UserGroupInformation ugi,
       @PathParam(UriFsPathParam.NAME) final UriFsPathParam path,
       @QueryParam(PutOpParam.NAME) @DefaultValue(PutOpParam.DEFAULT)
           final PutOpParam op,
@@ -91,14 +94,18 @@ public class DatanodeWebHdfsMethods {
           final ReplicationParam replication,
       @QueryParam(BlockSizeParam.NAME) @DefaultValue(BlockSizeParam.DEFAULT)
           final BlockSizeParam blockSize
-      ) throws IOException, URISyntaxException {
+      ) throws IOException, URISyntaxException, InterruptedException {
 
     if (LOG.isTraceEnabled()) {
-      LOG.trace(op + ": " + path
-            + Param.toSortedString(", ", permission, overwrite, bufferSize,
-                replication, blockSize));
+      LOG.trace(op + ": " + path + ", ugi=" + ugi
+          + Param.toSortedString(", ", permission, overwrite, bufferSize,
+              replication, blockSize));
     }
 
+    return ugi.doAs(new PrivilegedExceptionAction<Response>() {
+      @Override
+      public Response run() throws IOException, URISyntaxException {
+
     final String fullpath = path.getAbsolutePath();
     final DataNode datanode = (DataNode)context.getAttribute("datanode");
 
@@ -108,14 +115,14 @@ public class DatanodeWebHdfsMethods {
       final Configuration conf = new Configuration(datanode.getConf());
       final InetSocketAddress nnRpcAddr = NameNode.getAddress(conf);
       final DFSClient dfsclient = new DFSClient(nnRpcAddr, conf);
+      final int b = bufferSize.getValue(conf);
       final FSDataOutputStream out = new FSDataOutputStream(dfsclient.create(
           fullpath, permission.getFsPermission(), 
           overwrite.getValue() ? EnumSet.of(CreateFlag.CREATE, CreateFlag.OVERWRITE)
               : EnumSet.of(CreateFlag.CREATE),
-          replication.getValue(), blockSize.getValue(), null,
-          bufferSize.getValue()), null);
+          replication.getValue(), blockSize.getValue(conf), null, b), null);
       try {
-        IOUtils.copyBytes(in, out, bufferSize.getValue());
+        IOUtils.copyBytes(in, out, b);
       } finally {
         out.close();
       }
@@ -127,6 +134,8 @@ public class DatanodeWebHdfsMethods {
     default:
       throw new UnsupportedOperationException(op + " is not supported");
     }
+      }
+    });
   }
 
   /** Handle HTTP POST request. */
@@ -136,18 +145,23 @@ public class DatanodeWebHdfsMethods {
   @Produces({MediaType.APPLICATION_JSON})
   public Response post(
       final InputStream in,
+      @Context final UserGroupInformation ugi,
       @PathParam(UriFsPathParam.NAME) final UriFsPathParam path,
       @QueryParam(PostOpParam.NAME) @DefaultValue(PostOpParam.DEFAULT)
           final PostOpParam op,
       @QueryParam(BufferSizeParam.NAME) @DefaultValue(BufferSizeParam.DEFAULT)
           final BufferSizeParam bufferSize
-      ) throws IOException, URISyntaxException {
+      ) throws IOException, URISyntaxException, InterruptedException {
 
     if (LOG.isTraceEnabled()) {
-      LOG.trace(op + ": " + path
-            + Param.toSortedString(", ", bufferSize));
+      LOG.trace(op + ": " + path + ", ugi=" + ugi
+          + Param.toSortedString(", ", bufferSize));
     }
 
+    return ugi.doAs(new PrivilegedExceptionAction<Response>() {
+      @Override
+      public Response run() throws IOException {
+
     final String fullpath = path.getAbsolutePath();
     final DataNode datanode = (DataNode)context.getAttribute("datanode");
 
@@ -157,10 +171,10 @@ public class DatanodeWebHdfsMethods {
       final Configuration conf = new Configuration(datanode.getConf());
       final InetSocketAddress nnRpcAddr = NameNode.getAddress(conf);
       final DFSClient dfsclient = new DFSClient(nnRpcAddr, conf);
-      final FSDataOutputStream out = dfsclient.append(fullpath,
-          bufferSize.getValue(), null, null);
+      final int b = bufferSize.getValue(conf);
+      final FSDataOutputStream out = dfsclient.append(fullpath, b, null, null);
       try {
-        IOUtils.copyBytes(in, out, bufferSize.getValue());
+        IOUtils.copyBytes(in, out, b);
       } finally {
         out.close();
       }
@@ -169,6 +183,8 @@ public class DatanodeWebHdfsMethods {
     default:
       throw new UnsupportedOperationException(op + " is not supported");
     }
+      }
+    });
   }
 
   /** Handle HTTP GET request. */
@@ -176,6 +192,7 @@ public class DatanodeWebHdfsMethods {
   @Path("{" + UriFsPathParam.NAME + ":.*}")
   @Produces({MediaType.APPLICATION_OCTET_STREAM, MediaType.APPLICATION_JSON})
   public Response get(
+      @Context final UserGroupInformation ugi,
       @PathParam(UriFsPathParam.NAME) final UriFsPathParam path,
       @QueryParam(GetOpParam.NAME) @DefaultValue(GetOpParam.DEFAULT)
           final GetOpParam op,
@@ -185,13 +202,17 @@ public class DatanodeWebHdfsMethods {
           final LengthParam length,
       @QueryParam(BufferSizeParam.NAME) @DefaultValue(BufferSizeParam.DEFAULT)
           final BufferSizeParam bufferSize
-      ) throws IOException, URISyntaxException {
+      ) throws IOException, URISyntaxException, InterruptedException {
 
     if (LOG.isTraceEnabled()) {
-      LOG.trace(op + ": " + path
-            + Param.toSortedString(", ", offset, length, bufferSize));
+      LOG.trace(op + ": " + path + ", ugi=" + ugi
+          + Param.toSortedString(", ", offset, length, bufferSize));
     }
 
+    return ugi.doAs(new PrivilegedExceptionAction<Response>() {
+      @Override
+      public Response run() throws IOException {
+
     final String fullpath = path.getAbsolutePath();
     final DataNode datanode = (DataNode)context.getAttribute("datanode");
 
@@ -201,8 +222,9 @@ public class DatanodeWebHdfsMethods {
       final Configuration conf = new Configuration(datanode.getConf());
       final InetSocketAddress nnRpcAddr = NameNode.getAddress(conf);
       final DFSClient dfsclient = new DFSClient(nnRpcAddr, conf);
+      final int b = bufferSize.getValue(conf);
       final DFSDataInputStream in = new DFSClient.DFSDataInputStream(
-          dfsclient.open(fullpath, bufferSize.getValue(), true));
+          dfsclient.open(fullpath, b, true));
       in.seek(offset.getValue());
 
       final StreamingOutput streaming = new StreamingOutput() {
@@ -210,7 +232,7 @@ public class DatanodeWebHdfsMethods {
         public void write(final OutputStream out) throws IOException {
           final Long n = length.getValue();
           if (n == null) {
-            IOUtils.copyBytes(in, out, bufferSize.getValue());
+            IOUtils.copyBytes(in, out, b);
           } else {
             IOUtils.copyBytes(in, out, n, false);
           }
@@ -221,5 +243,7 @@ public class DatanodeWebHdfsMethods {
     default:
       throw new UnsupportedOperationException(op + " is not supported");
     }
+      }
+    });
   }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/GetDelegationTokenServlet.java

@@ -28,11 +28,9 @@ import javax.servlet.http.HttpServletResponse;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenIdentifier;
-import org.apache.hadoop.io.Text;
+import org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenSecretManager;
 import org.apache.hadoop.security.Credentials;
 import org.apache.hadoop.security.UserGroupInformation;
-import org.apache.hadoop.security.token.Token;
 
 /**
  * Serve delegation tokens over http for use in hftp.
@@ -70,18 +68,9 @@ public class GetDelegationTokenServlet extends DfsServlet {
       final DataOutputStream dosFinal = dos; // for doAs block
       ugi.doAs(new PrivilegedExceptionAction<Void>() {
         @Override
-        public Void run() throws Exception {
-          String s = NameNode.getAddress(conf).getAddress().getHostAddress()
-          + ":" + NameNode.getAddress(conf).getPort();
-
-          Token<DelegationTokenIdentifier> token = 
-            nn.getRpcServer().getDelegationToken(new Text(renewerFinal));
-          if(token == null) {
-            throw new Exception("couldn't get the token for " +s);
-          }
-          token.setService(new Text(s));
-          Credentials ts = new Credentials();
-          ts.addToken(new Text(ugi.getShortUserName()), token);
+        public Void run() throws IOException {
+          final Credentials ts = DelegationTokenSecretManager.createCredentials(
+              nn, ugi, renewerFinal);
           ts.write(dosFinal);
           return null;
         }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNodeHttpServer.java

@@ -30,6 +30,7 @@ import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.HdfsConfiguration;
 import org.apache.hadoop.hdfs.server.common.JspHelper;
 import org.apache.hadoop.hdfs.server.namenode.web.resources.NamenodeWebHdfsMethods;
+import org.apache.hadoop.hdfs.web.AuthFilter;
 import org.apache.hadoop.hdfs.web.WebHdfsFileSystem;
 import org.apache.hadoop.hdfs.web.resources.Param;
 import org.apache.hadoop.http.HttpServer;
@@ -99,7 +100,25 @@ public class NameNodeHttpServer {
           int infoPort = bindAddress.getPort();
           httpServer = new HttpServer("hdfs", infoHost, infoPort,
               infoPort == 0, conf, 
-              new AccessControlList(conf.get(DFSConfigKeys.DFS_ADMIN, " ")));
+              new AccessControlList(conf.get(DFSConfigKeys.DFS_ADMIN, " "))) {
+            {
+              if (conf.getBoolean(DFSConfigKeys.DFS_WEBHDFS_ENABLED_KEY,
+                  DFSConfigKeys.DFS_WEBHDFS_ENABLED_DEFAULT)) {
+                //add SPNEGO authentication filter for webhdfs
+                final String name = "SPNEGO";
+                final String classname =  AuthFilter.class.getName();
+                final String pathSpec = "/" + WebHdfsFileSystem.PATH_PREFIX + "/*";
+                defineFilter(webAppContext, name, classname, null,
+                    new String[]{pathSpec});
+                LOG.info("Added filter '" + name + "' (class=" + classname + ")");
+
+                // add webhdfs packages
+                addJerseyResourcePackage(
+                    NamenodeWebHdfsMethods.class.getPackage().getName()
+                    + ";" + Param.class.getPackage().getName(), pathSpec);
+              }
+            }
+          };
 
           boolean certSSL = conf.getBoolean("dfs.https.enable", false);
           boolean useKrb = UserGroupInformation.isSecurityEnabled();
@@ -181,13 +200,6 @@ public class NameNodeHttpServer {
         FileChecksumServlets.RedirectServlet.class, false);
     httpServer.addInternalServlet("contentSummary", "/contentSummary/*",
         ContentSummaryServlet.class, false);
-
-    if (conf.getBoolean(DFSConfigKeys.DFS_WEBHDFS_ENABLED_KEY,
-        DFSConfigKeys.DFS_WEBHDFS_ENABLED_DEFAULT)) {
-      httpServer.addJerseyResourcePackage(NamenodeWebHdfsMethods.class
-          .getPackage().getName() + ";" + Param.class.getPackage().getName(),
-          "/" + WebHdfsFileSystem.PATH_PREFIX + "/*");
-    }
   }
 
   public static FSImage getFsImageFromContext(ServletContext context) {

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/web/resources/NamenodeWebHdfsMethods.java

@@ -24,9 +24,11 @@ import java.io.OutputStream;
 import java.io.PrintStream;
 import java.net.URI;
 import java.net.URISyntaxException;
+import java.security.PrivilegedExceptionAction;
 import java.util.EnumSet;
 
 import javax.servlet.ServletContext;
+import javax.servlet.http.HttpServletRequest;
 import javax.ws.rs.Consumes;
 import javax.ws.rs.DELETE;
 import javax.ws.rs.DefaultValue;
@@ -49,6 +51,7 @@ import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
 import org.apache.hadoop.hdfs.protocol.DirectoryListing;
 import org.apache.hadoop.hdfs.protocol.HdfsFileStatus;
 import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
+import org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenSecretManager;
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeDescriptor;
 import org.apache.hadoop.hdfs.server.common.JspHelper;
 import org.apache.hadoop.hdfs.server.namenode.NameNode;
@@ -58,6 +61,7 @@ import org.apache.hadoop.hdfs.web.WebHdfsFileSystem;
 import org.apache.hadoop.hdfs.web.resources.AccessTimeParam;
 import org.apache.hadoop.hdfs.web.resources.BlockSizeParam;
 import org.apache.hadoop.hdfs.web.resources.BufferSizeParam;
+import org.apache.hadoop.hdfs.web.resources.DelegationParam;
 import org.apache.hadoop.hdfs.web.resources.DeleteOpParam;
 import org.apache.hadoop.hdfs.web.resources.DstPathParam;
 import org.apache.hadoop.hdfs.web.resources.GetOpParam;
@@ -76,7 +80,14 @@ import org.apache.hadoop.hdfs.web.resources.RecursiveParam;
 import org.apache.hadoop.hdfs.web.resources.RenameOptionSetParam;
 import org.apache.hadoop.hdfs.web.resources.ReplicationParam;
 import org.apache.hadoop.hdfs.web.resources.UriFsPathParam;
+import org.apache.hadoop.hdfs.web.resources.UserParam;
+import org.apache.hadoop.io.Text;
 import org.apache.hadoop.net.NodeBase;
+import org.apache.hadoop.security.Credentials;
+import org.apache.hadoop.security.SecurityUtil;
+import org.apache.hadoop.security.UserGroupInformation;
+import org.apache.hadoop.security.token.Token;
+import org.apache.hadoop.security.token.TokenIdentifier;
 
 /** Web-hdfs NameNode implementation. */
 @Path("")
@@ -84,6 +95,7 @@ public class NamenodeWebHdfsMethods {
   private static final Log LOG = LogFactory.getLog(NamenodeWebHdfsMethods.class);
 
   private @Context ServletContext context;
+  private @Context HttpServletRequest request;
 
   private static DatanodeInfo chooseDatanode(final NameNode namenode,
       final String path, final HttpOpParam.Op op, final long openOffset
@@ -112,11 +124,40 @@ public class NamenodeWebHdfsMethods {
         NodeBase.ROOT);
   }
 
-  private static URI redirectURI(final NameNode namenode,
+  private Token<? extends TokenIdentifier> generateDelegationToken(
+      final NameNode namenode, final UserGroupInformation ugi,
+      final String renewer) throws IOException {
+    final Credentials c = DelegationTokenSecretManager.createCredentials(
+        namenode, ugi, request.getUserPrincipal().getName());
+    final Token<? extends TokenIdentifier> t = c.getAllTokens().iterator().next();
+    t.setService(new Text(SecurityUtil.buildDTServiceName(
+        NameNode.getUri(namenode.getNameNodeAddress()),
+        NameNode.DEFAULT_PORT)));
+    return t;
+  }
+
+  private URI redirectURI(final NameNode namenode,
+      final UserGroupInformation ugi, final DelegationParam delegation,
       final String path, final HttpOpParam.Op op, final long openOffset,
       final Param<?, ?>... parameters) throws URISyntaxException, IOException {
     final DatanodeInfo dn = chooseDatanode(namenode, path, op, openOffset);
-    final String query = op.toQueryString() + Param.toSortedString("&", parameters);
+
+    final String delegationQuery;
+    if (!UserGroupInformation.isSecurityEnabled()) {
+      //security disabled
+      delegationQuery = "";
+    } else if (delegation.getValue() != null) {
+      //client has provided a token
+      delegationQuery = "&" + delegation;
+    } else {
+      //generate a token
+      final Token<? extends TokenIdentifier> t = generateDelegationToken(
+          namenode, ugi, request.getUserPrincipal().getName());
+      delegationQuery = "&" + new DelegationParam(t.encodeToUrlString());
+    }
+    final String query = op.toQueryString()
+        + '&' + new UserParam(ugi) + delegationQuery
+        + Param.toSortedString("&", parameters);
     final String uripath = "/" + WebHdfsFileSystem.PATH_PREFIX + path;
 
     final URI uri = new URI("http", null, dn.getHostName(), dn.getInfoPort(),
@@ -134,6 +175,9 @@ public class NamenodeWebHdfsMethods {
   @Produces({MediaType.APPLICATION_JSON})
   public Response put(
       final InputStream in,
+      @Context final UserGroupInformation ugi,
+      @QueryParam(DelegationParam.NAME) @DefaultValue(DelegationParam.DEFAULT)
+          final DelegationParam delegation,
       @PathParam(UriFsPathParam.NAME) final UriFsPathParam path,
       @QueryParam(PutOpParam.NAME) @DefaultValue(PutOpParam.DEFAULT)
           final PutOpParam op,
@@ -159,15 +203,19 @@ public class NamenodeWebHdfsMethods {
           final AccessTimeParam accessTime,
       @QueryParam(RenameOptionSetParam.NAME) @DefaultValue(RenameOptionSetParam.DEFAULT)
           final RenameOptionSetParam renameOptions
-      ) throws IOException, URISyntaxException {
+      ) throws IOException, URISyntaxException, InterruptedException {
 
     if (LOG.isTraceEnabled()) {
-      LOG.trace(op + ": " + path
+      LOG.trace(op + ": " + path + ", ugi=" + ugi
           + Param.toSortedString(", ", dstPath, owner, group, permission,
               overwrite, bufferSize, replication, blockSize,
               modificationTime, accessTime, renameOptions));
     }
 
+    return ugi.doAs(new PrivilegedExceptionAction<Response>() {
+      @Override
+      public Response run() throws IOException, URISyntaxException {
+
     final String fullpath = path.getAbsolutePath();
     final NameNode namenode = (NameNode)context.getAttribute("name.node");
     final NamenodeProtocols np = namenode.getRpcServer();
@@ -175,7 +223,8 @@ public class NamenodeWebHdfsMethods {
     switch(op.getValue()) {
     case CREATE:
     {
-      final URI uri = redirectURI(namenode, fullpath, op.getValue(), -1L,
+      final URI uri = redirectURI(namenode, ugi, delegation, fullpath,
+          op.getValue(), -1L,
           permission, overwrite, bufferSize, replication, blockSize);
       return Response.temporaryRedirect(uri).build();
     } 
@@ -223,6 +272,8 @@ public class NamenodeWebHdfsMethods {
     default:
       throw new UnsupportedOperationException(op + " is not supported");
     }
+      }
+    });
   }
 
   /** Handle HTTP POST request. */
@@ -232,31 +283,40 @@ public class NamenodeWebHdfsMethods {
   @Produces({MediaType.APPLICATION_JSON})
   public Response post(
       final InputStream in,
+      @Context final UserGroupInformation ugi,
+      @QueryParam(DelegationParam.NAME) @DefaultValue(DelegationParam.DEFAULT)
+          final DelegationParam delegation,
       @PathParam(UriFsPathParam.NAME) final UriFsPathParam path,
       @QueryParam(PostOpParam.NAME) @DefaultValue(PostOpParam.DEFAULT)
           final PostOpParam op,
       @QueryParam(BufferSizeParam.NAME) @DefaultValue(BufferSizeParam.DEFAULT)
           final BufferSizeParam bufferSize
-      ) throws IOException, URISyntaxException {
+      ) throws IOException, URISyntaxException, InterruptedException {
 
     if (LOG.isTraceEnabled()) {
-      LOG.trace(op + ": " + path
-            + Param.toSortedString(", ", bufferSize));
+      LOG.trace(op + ": " + path + ", ugi=" + ugi
+          + Param.toSortedString(", ", bufferSize));
     }
 
+    return ugi.doAs(new PrivilegedExceptionAction<Response>() {
+      @Override
+      public Response run() throws IOException, URISyntaxException {
+
     final String fullpath = path.getAbsolutePath();
     final NameNode namenode = (NameNode)context.getAttribute("name.node");
 
     switch(op.getValue()) {
     case APPEND:
     {
-      final URI uri = redirectURI(namenode, fullpath, op.getValue(), -1L,
-          bufferSize);
+      final URI uri = redirectURI(namenode, ugi, delegation, fullpath,
+          op.getValue(), -1L, bufferSize);
       return Response.temporaryRedirect(uri).build();
     }
     default:
       throw new UnsupportedOperationException(op + " is not supported");
     }
+      }
+    });
   }
 
   private static final UriFsPathParam ROOT = new UriFsPathParam("");
@@ -266,6 +326,9 @@ public class NamenodeWebHdfsMethods {
   @Path("/")
   @Produces({MediaType.APPLICATION_OCTET_STREAM, MediaType.APPLICATION_JSON})
   public Response root(
+      @Context final UserGroupInformation ugi,
+      @QueryParam(DelegationParam.NAME) @DefaultValue(DelegationParam.DEFAULT)
+          final DelegationParam delegation,
       @QueryParam(GetOpParam.NAME) @DefaultValue(GetOpParam.DEFAULT)
           final GetOpParam op,
       @QueryParam(OffsetParam.NAME) @DefaultValue(OffsetParam.DEFAULT)
@@ -274,8 +337,8 @@ public class NamenodeWebHdfsMethods {
           final LengthParam length,
       @QueryParam(BufferSizeParam.NAME) @DefaultValue(BufferSizeParam.DEFAULT)
           final BufferSizeParam bufferSize
-      ) throws IOException, URISyntaxException {
-    return get(ROOT, op, offset, length, bufferSize);
+      ) throws IOException, URISyntaxException, InterruptedException {
+    return get(ugi, delegation, ROOT, op, offset, length, bufferSize);
   }
 
   /** Handle HTTP GET request. */
@@ -283,6 +346,9 @@ public class NamenodeWebHdfsMethods {
   @Path("{" + UriFsPathParam.NAME + ":.*}")
   @Produces({MediaType.APPLICATION_OCTET_STREAM, MediaType.APPLICATION_JSON})
   public Response get(
+      @Context final UserGroupInformation ugi,
+      @QueryParam(DelegationParam.NAME) @DefaultValue(DelegationParam.DEFAULT)
+          final DelegationParam delegation,
       @PathParam(UriFsPathParam.NAME) final UriFsPathParam path,
       @QueryParam(GetOpParam.NAME) @DefaultValue(GetOpParam.DEFAULT)
           final GetOpParam op,
@@ -292,13 +358,18 @@ public class NamenodeWebHdfsMethods {
           final LengthParam length,
       @QueryParam(BufferSizeParam.NAME) @DefaultValue(BufferSizeParam.DEFAULT)
           final BufferSizeParam bufferSize
-      ) throws IOException, URISyntaxException {
+      ) throws IOException, URISyntaxException, InterruptedException {
 
     if (LOG.isTraceEnabled()) {
-      LOG.trace(op + ", " + path
+      LOG.trace(op + ": " + path + ", ugi=" + ugi
           + Param.toSortedString(", ", offset, length, bufferSize));
     }
 
+
+    return ugi.doAs(new PrivilegedExceptionAction<Response>() {
+      @Override
+      public Response run() throws IOException, URISyntaxException {
+
     final NameNode namenode = (NameNode)context.getAttribute("name.node");
     final String fullpath = path.getAbsolutePath();
     final NamenodeProtocols np = namenode.getRpcServer();
@@ -306,8 +377,8 @@ public class NamenodeWebHdfsMethods {
     switch(op.getValue()) {
     case OPEN:
     {
-      final URI uri = redirectURI(namenode, fullpath, op.getValue(),
-          offset.getValue(), offset, length, bufferSize);
+      final URI uri = redirectURI(namenode, ugi, delegation, fullpath,
+          op.getValue(), offset.getValue(), offset, length, bufferSize);
       return Response.temporaryRedirect(uri).build();
     }
     case GETFILESTATUS:
@@ -324,6 +395,8 @@ public class NamenodeWebHdfsMethods {
     default:
       throw new UnsupportedOperationException(op + " is not supported");
     }    
+      }
+    });
   }
 
   private static DirectoryListing getDirectoryListing(final NamenodeProtocols np,
@@ -373,28 +446,36 @@ public class NamenodeWebHdfsMethods {
   @Path("{path:.*}")
   @Produces(MediaType.APPLICATION_JSON)
   public Response delete(
+      @Context final UserGroupInformation ugi,
       @PathParam(UriFsPathParam.NAME) final UriFsPathParam path,
       @QueryParam(DeleteOpParam.NAME) @DefaultValue(DeleteOpParam.DEFAULT)
           final DeleteOpParam op,
       @QueryParam(RecursiveParam.NAME) @DefaultValue(RecursiveParam.DEFAULT)
           final RecursiveParam recursive
-      ) throws IOException {
+      ) throws IOException, InterruptedException {
 
     if (LOG.isTraceEnabled()) {
-      LOG.trace(op + ", " + path
-        + Param.toSortedString(", ", recursive));
+      LOG.trace(op + ": " + path + ", ugi=" + ugi
+          + Param.toSortedString(", ", recursive));
     }
 
-    switch(op.getValue()) {
-    case DELETE:
-      final NameNode namenode = (NameNode)context.getAttribute("name.node");
-      final String fullpath = path.getAbsolutePath();
-      final boolean b = namenode.getRpcServer().delete(fullpath, recursive.getValue());
-      final String js = JsonUtil.toJsonString(DeleteOpParam.Op.DELETE, b);
-      return Response.ok(js).type(MediaType.APPLICATION_JSON).build();
+    return ugi.doAs(new PrivilegedExceptionAction<Response>() {
+      @Override
+      public Response run() throws IOException {
+        final NameNode namenode = (NameNode)context.getAttribute("name.node");
+        final String fullpath = path.getAbsolutePath();
 
-    default:
-      throw new UnsupportedOperationException(op + " is not supported");
-    }    
+        switch(op.getValue()) {
+        case DELETE:
+        {
+          final boolean b = namenode.getRpcServer().delete(fullpath, recursive.getValue());
+          final String js = JsonUtil.toJsonString(DeleteOpParam.Op.DELETE, b);
+          return Response.ok(js).type(MediaType.APPLICATION_JSON).build();
+        }
+        default:
+          throw new UnsupportedOperationException(op + " is not supported");
+        }
+      }
+    });
   }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/AuthFilter.java

@@ -0,0 +1,70 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     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.
+ */
+package org.apache.hadoop.hdfs.web;
+
+import java.util.Map;
+import java.util.Properties;
+
+import javax.servlet.FilterConfig;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.security.UserGroupInformation;
+import org.apache.hadoop.security.authentication.server.AuthenticationFilter;
+import org.apache.hadoop.security.authentication.server.KerberosAuthenticationHandler;
+import org.apache.hadoop.security.authentication.server.PseudoAuthenticationHandler;
+
+/**
+ * Subclass of {@link AuthenticationFilter} that
+ * obtains Hadoop-Auth configuration for webhdfs.
+ */
+public class AuthFilter extends AuthenticationFilter {
+  private static final String CONF_PREFIX = "dfs.web.authentication.";
+
+  /**
+   * Returns the filter configuration properties,
+   * including the ones prefixed with {@link #CONF_PREFIX}.
+   * The prefix is removed from the returned property names.
+   *
+   * @param prefix parameter not used.
+   * @param config parameter not used.
+   * @return Hadoop-Auth configuration properties.
+   */
+  @Override
+  protected Properties getConfiguration(String prefix, FilterConfig config) {
+    final Configuration conf = new Configuration();
+    final Properties p = new Properties();
+
+    //set authentication type
+    p.setProperty(AUTH_TYPE, UserGroupInformation.isSecurityEnabled()?
+        KerberosAuthenticationHandler.TYPE: PseudoAuthenticationHandler.TYPE);
+    //For Pseudo Authentication, allow anonymous.
+    p.setProperty(PseudoAuthenticationHandler.ANONYMOUS_ALLOWED, "true");
+    //set cookie path
+    p.setProperty(COOKIE_PATH, "/");
+
+    //set other configurations with CONF_PREFIX
+    for (Map.Entry<String, String> entry : conf) {
+      final String key = entry.getKey();
+      if (key.startsWith(CONF_PREFIX)) {
+        //remove prefix from the key and set property
+        p.setProperty(key.substring(CONF_PREFIX.length()), conf.get(key));
+      }
+    }
+    return p;
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/KerberosUgiAuthenticator.java

@@ -0,0 +1,45 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     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.
+ */
+package org.apache.hadoop.hdfs.web;
+
+import java.io.IOException;
+
+import org.apache.hadoop.security.UserGroupInformation;
+import org.apache.hadoop.security.authentication.client.Authenticator;
+import org.apache.hadoop.security.authentication.client.KerberosAuthenticator;
+import org.apache.hadoop.security.authentication.client.PseudoAuthenticator;
+
+/**
+ * Use UserGroupInformation as a fallback authenticator
+ * if the server does not use Kerberos SPNEGO HTTP authentication.
+ */
+public class KerberosUgiAuthenticator extends KerberosAuthenticator {
+  @Override
+  protected Authenticator getFallBackAuthenticator() {
+    return new PseudoAuthenticator() {
+      @Override
+      protected String getUserName() {
+        try {
+          return UserGroupInformation.getLoginUser().getUserName();
+        } catch (IOException e) {
+          throw new SecurityException("Failed to obtain current username", e);
+        }
+      }
+    };
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/WebHdfsFileSystem.java

@@ -64,9 +64,12 @@ import org.apache.hadoop.hdfs.web.resources.PutOpParam;
 import org.apache.hadoop.hdfs.web.resources.RecursiveParam;
 import org.apache.hadoop.hdfs.web.resources.RenameOptionSetParam;
 import org.apache.hadoop.hdfs.web.resources.ReplicationParam;
+import org.apache.hadoop.hdfs.web.resources.UserParam;
 import org.apache.hadoop.ipc.RemoteException;
 import org.apache.hadoop.security.AccessControlException;
 import org.apache.hadoop.security.UserGroupInformation;
+import org.apache.hadoop.security.authentication.client.AuthenticatedURL;
+import org.apache.hadoop.security.authentication.client.AuthenticationException;
 import org.apache.hadoop.util.Progressable;
 import org.mortbay.util.ajax.JSON;
 
@@ -77,11 +80,15 @@ public class WebHdfsFileSystem extends HftpFileSystem {
   /** Http URI: http://namenode:port/{PATH_PREFIX}/path/to/file */
   public static final String PATH_PREFIX = SCHEME;
 
+  private static final KerberosUgiAuthenticator AUTH = new KerberosUgiAuthenticator();
+
   private UserGroupInformation ugi;
+  private final AuthenticatedURL.Token authToken = new AuthenticatedURL.Token();
   protected Path workingDir;
 
   @Override
-  public void initialize(URI uri, Configuration conf) throws IOException {
+  public synchronized void initialize(URI uri, Configuration conf
+      ) throws IOException {
     super.initialize(uri, conf);
     setConf(conf);
 
@@ -162,8 +169,9 @@ public class WebHdfsFileSystem extends HftpFileSystem {
     final String path = "/" + PATH_PREFIX
         + makeQualified(fspath).toUri().getPath();
     final String query = op.toQueryString()
+        + '&' + new UserParam(ugi)
         + Param.toSortedString("&", parameters);
-    final URL url = getNamenodeURL(path, query);
+    final URL url = getNamenodeURL(path, addDelegationTokenParam(query));
     if (LOG.isTraceEnabled()) {
       LOG.trace("url=" + url);
     }
@@ -175,7 +183,12 @@ public class WebHdfsFileSystem extends HftpFileSystem {
     final URL url = toUrl(op, fspath, parameters);
 
     //connect and get response
-    final HttpURLConnection conn = (HttpURLConnection)url.openConnection();
+    final HttpURLConnection conn;
+    try {
+      conn = new AuthenticatedURL(AUTH).openConnection(url, authToken);
+    } catch(AuthenticationException e) {
+      throw new IOException("Authentication failed, url=" + url, e);
+    }
     try {
       conn.setRequestMethod(op.getType().toString());
       conn.setDoOutput(op.getDoOutput());

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/resources/BlockSizeParam.java

@@ -17,6 +17,11 @@
  */
 package org.apache.hadoop.hdfs.web.resources;
 
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_BLOCK_SIZE_DEFAULT;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_BLOCK_SIZE_KEY;
+
+import org.apache.hadoop.conf.Configuration;
+
 /** Block size parameter. */
 public class BlockSizeParam extends LongParam {
   /** Parameter name. */
@@ -46,4 +51,10 @@ public class BlockSizeParam extends LongParam {
   public String getName() {
     return NAME;
   }
+
+  /** @return the value or, if it is null, return the default from conf. */
+  public long getValue(final Configuration conf) {
+    return getValue() != null? getValue()
+        : conf.getLong(DFS_BLOCK_SIZE_KEY, DFS_BLOCK_SIZE_DEFAULT);
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/resources/BufferSizeParam.java

@@ -17,6 +17,9 @@
  */
 package org.apache.hadoop.hdfs.web.resources;
 
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.CommonConfigurationKeysPublic;
+
 /** Buffer size parameter. */
 public class BufferSizeParam extends IntegerParam {
   /** Parameter name. */
@@ -46,4 +49,12 @@ public class BufferSizeParam extends IntegerParam {
   public String getName() {
     return NAME;
   }
+
+  /** @return the value or, if it is null, return the default from conf. */
+  public int getValue(final Configuration conf) {
+    return getValue() != null? getValue()
+        : conf.getInt(
+            CommonConfigurationKeysPublic.IO_FILE_BUFFER_SIZE_KEY,
+            CommonConfigurationKeysPublic.IO_FILE_BUFFER_SIZE_DEFAULT);
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/resources/DelegationParam.java

@@ -0,0 +1,45 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     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.
+ */
+package org.apache.hadoop.hdfs.web.resources;
+
+import org.apache.hadoop.hdfs.server.common.JspHelper;
+import org.apache.hadoop.security.UserGroupInformation;
+
+/** Delegation token parameter. */
+public class DelegationParam extends StringParam {
+  /** Parameter name. */
+  public static final String NAME = JspHelper.DELEGATION_PARAMETER_NAME;
+  /** Default parameter value. */
+  public static final String DEFAULT = "";
+
+  private static final Domain DOMAIN = new Domain(NAME, null);
+
+  /**
+   * Constructor.
+   * @param str a string representation of the parameter value.
+   */
+  public DelegationParam(final String str) {
+    super(DOMAIN, UserGroupInformation.isSecurityEnabled()
+        && str != null && !str.equals(DEFAULT)? str: null);
+  }
+
+  @Override
+  public String getName() {
+    return NAME;
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/resources/HttpOpParam.java

@@ -18,7 +18,8 @@
 package org.apache.hadoop.hdfs.web.resources;
 
 /** Http operation parameter. */
-public abstract class HttpOpParam<E extends Enum<E> & HttpOpParam.Op> extends EnumParam<E> {
+public abstract class HttpOpParam<E extends Enum<E> & HttpOpParam.Op>
+    extends EnumParam<E> {
   /** Default parameter value. */
   public static final String DEFAULT = NULL;
 
@@ -32,20 +33,16 @@ public abstract class HttpOpParam<E extends Enum<E> & HttpOpParam.Op> extends En
     /** @return the Http operation type. */
     public Type getType();
 
-    /** @return true if the operation has output. */
+    /** @return true if the operation will do output. */
     public boolean getDoOutput();
 
-    /** @return true if the operation has output. */
+    /** @return true the expected http response code. */
     public int getExpectedHttpResponseCode();
 
     /** @return a URI query string. */
     public String toQueryString();
   }
 
-  /**
-   * Constructor.
-   * @param str a string representation of the parameter value.
-   */
   HttpOpParam(final Domain<E> domain, final E value) {
     super(domain, value);
   }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/resources/UserParam.java

@@ -17,6 +17,8 @@
  */
 package org.apache.hadoop.hdfs.web.resources;
 
+import org.apache.hadoop.security.UserGroupInformation;
+
 /** User parameter. */
 public class UserParam extends StringParam {
   /** Parameter name. */
@@ -34,6 +36,13 @@ public class UserParam extends StringParam {
     super(DOMAIN, str == null || str.equals(DEFAULT)? null: str);
   }
 
+  /**
+   * Construct an object from a UGI.
+   */
+  public UserParam(final UserGroupInformation ugi) {
+    this(ugi.getShortUserName());
+  }
+
   @Override
   public String getName() {
     return NAME;

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/resources/UserProvider.java

@@ -17,12 +17,18 @@
  */
 package org.apache.hadoop.hdfs.web.resources;
 
+import java.io.IOException;
 import java.lang.reflect.Type;
-import java.security.Principal;
 
+import javax.servlet.http.HttpServletRequest;
 import javax.ws.rs.core.Context;
 import javax.ws.rs.ext.Provider;
 
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hdfs.server.common.JspHelper;
+import org.apache.hadoop.security.UserGroupInformation;
+import org.apache.hadoop.security.UserGroupInformation.AuthenticationMethod;
+
 import com.sun.jersey.api.core.HttpContext;
 import com.sun.jersey.core.spi.component.ComponentContext;
 import com.sun.jersey.core.spi.component.ComponentScope;
@@ -30,33 +36,23 @@ import com.sun.jersey.server.impl.inject.AbstractHttpContextInjectable;
 import com.sun.jersey.spi.inject.Injectable;
 import com.sun.jersey.spi.inject.InjectableProvider;
 
+/** Inject user information to http operations. */
 @Provider
-public class UserProvider extends AbstractHttpContextInjectable<Principal>
+public class UserProvider
+    extends AbstractHttpContextInjectable<UserGroupInformation>
     implements InjectableProvider<Context, Type> {
+  @Context HttpServletRequest request;
 
   @Override
-  public Principal getValue(final HttpContext context) {
-    //get principal from the request
-    final Principal principal = context.getRequest().getUserPrincipal();
-    if (principal != null) {
-      return principal;
+  public UserGroupInformation getValue(final HttpContext context) {
+    final Configuration conf = (Configuration)context.getProperties().get(
+        JspHelper.CURRENT_CONF);
+    try {
+      return JspHelper.getUGI(null, request, conf,
+          AuthenticationMethod.KERBEROS, false);
+    } catch (IOException e) {
+      throw new RuntimeException(e);
     }
-
-    //get username from the parameter
-    final String username = context.getRequest().getQueryParameters().getFirst(
-        UserParam.NAME);
-    if (username != null) {
-      final UserParam userparam = new UserParam(username);
-      return new Principal() {
-        @Override
-        public String getName() {
-          return userparam.getValue();
-        }
-      };
-    }
-
-    //user not found
-    return null;
   }
 
   @Override
@@ -65,9 +61,9 @@ public class UserProvider extends AbstractHttpContextInjectable<Principal>
   }
 
   @Override
-  public Injectable<Principal> getInjectable(
+  public Injectable<UserGroupInformation> getInjectable(
       final ComponentContext componentContext, final Context context,
       final Type type) {
-    return type.equals(Principal.class)? this : null;
+    return type.equals(UserGroupInformation.class)? this : null;
   }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml

@@ -683,4 +683,24 @@ creations/deletions), or "all".</description>
   </description>
 </property>
 
+<property>
+  <name>dfs.web.authentication.kerberos.principal</name>
+  <value>HTTP/${dfs.web.hostname}@${kerberos.realm}</value>
+  <description>
+    The HTTP Kerberos principal used by Hadoop-Auth in the HTTP endpoint.
+
+    The HTTP Kerberos principal MUST start with 'HTTP/' per Kerberos
+    HTTP SPENGO specification.
+  </description>
+</property>
+
+<property>
+  <name>dfs.web.authentication.kerberos.keytab</name>
+  <value>${user.home}/dfs.web.keytab</value>
+  <description>
+    The Kerberos keytab file with the credentials for the
+    HTTP Kerberos principal used by Hadoop-Auth in the HTTP endpoint.
+  </description>
+</property>
+
 </configuration>

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/web/TestFSMainOperationsWebHdfs.java

@@ -17,19 +17,28 @@
  */
 package org.apache.hadoop.hdfs.web;
 
+import static org.apache.hadoop.fs.FileSystemTestHelper.exists;
+import static org.apache.hadoop.fs.FileSystemTestHelper.getTestRootPath;
+
+import java.io.IOException;
 import java.net.URI;
+import java.security.PrivilegedExceptionAction;
 
 import org.apache.commons.logging.impl.Log4JLogger;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FSMainOperationsBaseTest;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.fs.permission.FsPermission;
 import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.MiniDFSCluster;
 import org.apache.hadoop.hdfs.server.datanode.web.resources.DatanodeWebHdfsMethods;
 import org.apache.hadoop.hdfs.web.resources.ExceptionHandler;
+import org.apache.hadoop.security.AccessControlException;
+import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.log4j.Level;
 import org.junit.AfterClass;
+import org.junit.Assert;
 import org.junit.BeforeClass;
 import org.junit.Test;
 
@@ -44,14 +53,30 @@ public class TestFSMainOperationsWebHdfs extends FSMainOperationsBaseTest {
 
   @BeforeClass
   public static void setupCluster() {
-    Configuration conf = new Configuration();
+    final Configuration conf = new Configuration();
+    conf.setBoolean(DFSConfigKeys.DFS_WEBHDFS_ENABLED_KEY, true);
     try {
       cluster = new MiniDFSCluster.Builder(conf).numDataNodes(2).build();
       cluster.waitActive();
 
+      //change root permission to 777
+      cluster.getFileSystem().setPermission(
+          new Path("/"), new FsPermission((short)0777));
+
       final String uri = WebHdfsFileSystem.SCHEME  + "://"
           + conf.get(DFSConfigKeys.DFS_NAMENODE_HTTP_ADDRESS_KEY);
-      fSys = FileSystem.get(new URI(uri), conf); 
+
+      //get file system as a non-superuser
+      final UserGroupInformation current = UserGroupInformation.getCurrentUser();
+      final UserGroupInformation ugi = UserGroupInformation.createUserForTesting(
+          current.getShortUserName() + "x", new String[]{"user"});
+      fSys = ugi.doAs(new PrivilegedExceptionAction<FileSystem>() {
+        @Override
+        public FileSystem run() throws Exception {
+          return FileSystem.get(new URI(uri), conf);
+        }
+      });
+
       defaultWorkingDirectory = fSys.getWorkingDirectory();
     } catch (Exception e) {
       throw new RuntimeException(e);
@@ -71,9 +96,39 @@ public class TestFSMainOperationsWebHdfs extends FSMainOperationsBaseTest {
     return defaultWorkingDirectory;
   }
 
-  //The following test failed since WebHdfsFileSystem did not support
-  //authentication.
-  //Disable it.
   @Test
-  public void testListStatusThrowsExceptionForUnreadableDir() {}
+  public void testMkdirsFailsForSubdirectoryOfExistingFile() throws Exception {
+    Path testDir = getTestRootPath(fSys, "test/hadoop");
+    Assert.assertFalse(exists(fSys, testDir));
+    fSys.mkdirs(testDir);
+    Assert.assertTrue(exists(fSys, testDir));
+    
+    createFile(getTestRootPath(fSys, "test/hadoop/file"));
+    
+    Path testSubDir = getTestRootPath(fSys, "test/hadoop/file/subdir");
+    try {
+      fSys.mkdirs(testSubDir);
+      Assert.fail("Should throw IOException.");
+    } catch (IOException e) {
+      // expected
+    }
+    try {
+      Assert.assertFalse(exists(fSys, testSubDir));
+    } catch(AccessControlException e) {
+      // also okay for HDFS.
+    }
+    
+    Path testDeepSubDir = getTestRootPath(fSys, "test/hadoop/file/deep/sub/dir");
+    try {
+      fSys.mkdirs(testDeepSubDir);
+      Assert.fail("Should throw IOException.");
+    } catch (IOException e) {
+      // expected
+    }
+    try {
+      Assert.assertFalse(exists(fSys, testDeepSubDir));
+    } catch(AccessControlException e) {
+      // also okay for HDFS.
+    }    
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/web/TestWebHdfsFileSystemContract.java

@@ -20,12 +20,17 @@ package org.apache.hadoop.hdfs.web;
 
 import java.io.IOException;
 import java.net.URI;
+import java.security.PrivilegedExceptionAction;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.FileSystemContractBaseTest;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.fs.permission.FsPermission;
 import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.MiniDFSCluster;
+import org.apache.hadoop.security.AccessControlException;
+import org.apache.hadoop.security.UserGroupInformation;
 
 public class TestWebHdfsFileSystemContract extends FileSystemContractBaseTest {
   private static final Configuration conf = new Configuration();
@@ -33,9 +38,14 @@ public class TestWebHdfsFileSystemContract extends FileSystemContractBaseTest {
   private String defaultWorkingDirectory;
 
   static {
+    conf.setBoolean(DFSConfigKeys.DFS_WEBHDFS_ENABLED_KEY, true);
     try {
       cluster = new MiniDFSCluster.Builder(conf).numDataNodes(2).build();
       cluster.waitActive();
+
+      //change root permission to 777
+      cluster.getFileSystem().setPermission(
+          new Path("/"), new FsPermission((short)0777));
     } catch (IOException e) {
       throw new RuntimeException(e);
     }
@@ -45,7 +55,18 @@ public class TestWebHdfsFileSystemContract extends FileSystemContractBaseTest {
   protected void setUp() throws Exception {
     final String uri = WebHdfsFileSystem.SCHEME  + "://"
         + conf.get(DFSConfigKeys.DFS_NAMENODE_HTTP_ADDRESS_KEY);
-    fs = FileSystem.get(new URI(uri), conf); 
+
+    //get file system as a non-superuser
+    final UserGroupInformation current = UserGroupInformation.getCurrentUser();
+    final UserGroupInformation ugi = UserGroupInformation.createUserForTesting(
+        current.getShortUserName() + "x", new String[]{"user"});
+    fs = ugi.doAs(new PrivilegedExceptionAction<FileSystem>() {
+      @Override
+      public FileSystem run() throws Exception {
+        return FileSystem.get(new URI(uri), conf);
+      }
+    });
+
     defaultWorkingDirectory = fs.getWorkingDirectory().toUri().getPath();
   }
 
@@ -53,4 +74,44 @@ public class TestWebHdfsFileSystemContract extends FileSystemContractBaseTest {
   protected String getDefaultWorkingDirectory() {
     return defaultWorkingDirectory;
   }
+
+  /** HDFS throws AccessControlException
+   * when calling exist(..) on a path /foo/bar/file
+   * but /foo/bar is indeed a file in HDFS.
+   */
+  @Override
+  public void testMkdirsFailsForSubdirectoryOfExistingFile() throws Exception {
+    Path testDir = path("/test/hadoop");
+    assertFalse(fs.exists(testDir));
+    assertTrue(fs.mkdirs(testDir));
+    assertTrue(fs.exists(testDir));
+    
+    createFile(path("/test/hadoop/file"));
+    
+    Path testSubDir = path("/test/hadoop/file/subdir");
+    try {
+      fs.mkdirs(testSubDir);
+      fail("Should throw IOException.");
+    } catch (IOException e) {
+      // expected
+    }
+    try {
+      assertFalse(fs.exists(testSubDir));
+    } catch(AccessControlException e) {
+      // also okay for HDFS.
+    }    
+    
+    Path testDeepSubDir = path("/test/hadoop/file/deep/sub/dir");
+    try {
+      fs.mkdirs(testDeepSubDir);
+      fail("Should throw IOException.");
+    } catch (IOException e) {
+      // expected
+    }
+    try {
+      assertFalse(fs.exists(testDeepSubDir));
+    } catch(AccessControlException e) {
+      // also okay for HDFS.
+    }    
+  }
 }