commit 4c8ff9967d58e9692e6f498c3324c551aa18251b

Author: Owen O'Malley <omalley@apache.org>
Date:   Fri Feb 26 11:28:36 2010 -0800

    HDFS-991. Use delegation token to authenticate to the hdfs servlets.
    
    +++ b/YAHOO-CHANGES.txt
    +    HDFS-991. Allow use of delegation tokens to authenticate to the
    +    HDFS servlets. (omalley)
    +


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.20-security-patches@1077236 13f79535-47bb-0310-9956-ffa450edef68

src/contrib/hdfsproxy/src/java/org/apache/hadoop/hdfsproxy/ProxyFileDataServlet.java

@@ -23,6 +23,7 @@ import java.net.URISyntaxException;
 
 import javax.servlet.http.HttpServletRequest;
 
+import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hdfs.protocol.ClientProtocol;
 import org.apache.hadoop.hdfs.protocol.HdfsFileStatus;
 import org.apache.hadoop.hdfs.server.namenode.FileDataServlet;
@@ -45,7 +46,8 @@ public class ProxyFileDataServlet extends FileDataServlet {
 
   /** {@inheritDoc} */
   @Override
-  protected UserGroupInformation getUGI(HttpServletRequest request) {
+  protected UserGroupInformation getUGI(HttpServletRequest request,
+                                        Configuration conf) {
     return (UserGroupInformation) request.getAttribute("authorized.ugi");
   }
 }

src/contrib/hdfsproxy/src/java/org/apache/hadoop/hdfsproxy/ProxyListPathsServlet.java

@@ -19,6 +19,7 @@ package org.apache.hadoop.hdfsproxy;
 
 import javax.servlet.http.HttpServletRequest;
 
+import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hdfs.server.namenode.ListPathsServlet;
 import org.apache.hadoop.security.UserGroupInformation;
 
@@ -29,7 +30,8 @@ public class ProxyListPathsServlet extends ListPathsServlet {
 
   /** {@inheritDoc} */
   @Override
-  protected UserGroupInformation getUGI(HttpServletRequest request) {
+  protected UserGroupInformation getUGI(HttpServletRequest request,
+                                        Configuration conf) {
     return (UserGroupInformation) request.getAttribute("authorized.ugi");
   }
 }

src/contrib/hdfsproxy/src/java/org/apache/hadoop/hdfsproxy/ProxyStreamFile.java

@@ -24,10 +24,10 @@ import java.security.PrivilegedExceptionAction;
 import javax.servlet.ServletContext;
 import javax.servlet.http.HttpServletRequest;
 
+import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hdfs.DFSClient;
 import org.apache.hadoop.hdfs.server.namenode.StreamFile;
 import org.apache.hadoop.security.UserGroupInformation;
-import org.apache.hadoop.conf.Configuration;
 
 /** {@inheritDoc} */
 public class ProxyStreamFile extends StreamFile {
@@ -36,27 +36,8 @@ public class ProxyStreamFile extends StreamFile {
 
   /** {@inheritDoc} */
   @Override
-  protected DFSClient getDFSClient(HttpServletRequest request)
-      throws IOException, InterruptedException {
-    ServletContext context = getServletContext();
-    final Configuration conf = new Configuration((Configuration) context
-        .getAttribute("name.conf"));
-    final InetSocketAddress nameNodeAddr = (InetSocketAddress) context
-        .getAttribute("name.node.address");
-    DFSClient client = 
-              getUGI(request).doAs(new PrivilegedExceptionAction<DFSClient>() {
-      @Override
-      public DFSClient run() throws IOException {
-        return new DFSClient(nameNodeAddr, conf);
-      }
-    });
-
-    return client;
-  }
-
-  /** {@inheritDoc} */
-  @Override
-  protected UserGroupInformation getUGI(HttpServletRequest request) {
+  protected UserGroupInformation getUGI(HttpServletRequest request,
+                                        Configuration conf) {
     return (UserGroupInformation) request.getAttribute("authorized.ugi");
   }
 }

src/hdfs/org/apache/hadoop/hdfs/server/datanode/DataNode.java

@@ -396,6 +396,7 @@ public class DataNode extends Configured
     this.infoServer.addInternalServlet(null, "/getFileChecksum/*",
         FileChecksumServlets.GetServlet.class);
     this.infoServer.setAttribute("datanode.blockScanner", blockScanner);
+    this.infoServer.setAttribute("datanode.conf", conf);
     this.infoServer.addServlet(null, "/blockScannerReport", 
                                DataBlockScanner.Servlet.class);
     this.infoServer.start();

src/hdfs/org/apache/hadoop/hdfs/server/namenode/ContentSummaryServlet.java

@@ -25,6 +25,7 @@ import javax.servlet.ServletException;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
+import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.ContentSummary;
 import org.apache.hadoop.hdfs.protocol.ClientProtocol;
 import org.apache.hadoop.ipc.RemoteException;
@@ -39,7 +40,9 @@ public class ContentSummaryServlet extends DfsServlet {
   /** {@inheritDoc} */
   public void doGet(final HttpServletRequest request,
       final HttpServletResponse response) throws ServletException, IOException {
-    final UserGroupInformation ugi = getUGI(request);
+    final Configuration conf = 
+      (Configuration) request.getAttribute("name.conf");
+    final UserGroupInformation ugi = getUGI(request, conf);
     try {
       ugi.doAs(new PrivilegedExceptionAction<Object>() {
         @Override

src/hdfs/org/apache/hadoop/hdfs/server/namenode/DfsServlet.java

@@ -47,31 +47,10 @@ abstract class DfsServlet extends HttpServlet {
 
   /** Get {@link UserGroupInformation} from request 
    *    * @throws IOException */
-  protected UserGroupInformation getUGI(HttpServletRequest request) 
-    throws IOException {
-    UserGroupInformation u = null;
-    if(UserGroupInformation.isSecurityEnabled()) {
-      String user = request.getRemoteUser();
-      if(user != null)
-        throw new IOException("Security enabled but user not " +
-            "authenticated by filter");
-
-      u = UserGroupInformation.createRemoteUser(user);
-    } else { // Security's not on, pull from url
-      String ugi = request.getParameter("ugi");
-
-      if(ugi == null) // not specified in request
-        ugi = new Configuration().get(JspHelper.WEB_UGI_PROPERTY_NAME);
-
-      if(ugi == null) // not specified in conf either
-        throw new IOException("Cannot determine UGI from request or conf");
-
-      u = UserGroupInformation.createRemoteUser(ugi);
-    }
-
-    if(LOG.isDebugEnabled())
-      LOG.debug("getUGI is returning: " + u.getShortUserName());
-    return u;
+  protected UserGroupInformation getUGI(HttpServletRequest request,
+                                        Configuration conf
+					) throws IOException {
+    return JspHelper.getUGI(request, conf);
   }
 
   /**

src/hdfs/org/apache/hadoop/hdfs/server/namenode/FileChecksumServlets.java

@@ -52,8 +52,9 @@ public class FileChecksumServlets {
     /** {@inheritDoc} */
     public void doGet(HttpServletRequest request, HttpServletResponse response
         ) throws ServletException, IOException {
-      final UserGroupInformation ugi = getUGI(request);
       final ServletContext context = getServletContext();
+      Configuration conf = (Configuration) context.getAttribute("name.conf");
+      final UserGroupInformation ugi = getUGI(request, conf);
       final NameNode namenode = (NameNode)context.getAttribute("name.node");
       final DatanodeID datanode = namenode.namesystem.getRandomDatanode();
       try {
@@ -86,7 +87,8 @@ public class FileChecksumServlets {
       final SocketFactory socketFactory = NetUtils.getSocketFactory(conf, ClientProtocol.class);
 
       try {
-        ClientProtocol nnproxy = getUGI(request).doAs(new PrivilegedExceptionAction<ClientProtocol>() {
+        ClientProtocol nnproxy = getUGI(request, conf).doAs
+        (new PrivilegedExceptionAction<ClientProtocol>() {
           @Override
           public ClientProtocol run() throws IOException {
             return DFSClient.createNamenode(conf);

src/hdfs/org/apache/hadoop/hdfs/server/namenode/FileDataServlet.java

@@ -24,6 +24,8 @@ import java.security.PrivilegedExceptionAction;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileStatus;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hdfs.protocol.ClientProtocol;
 import org.apache.hadoop.hdfs.protocol.DatanodeID;
@@ -88,7 +90,9 @@ public class FileDataServlet extends DfsServlet {
    */
   public void doGet(HttpServletRequest request, HttpServletResponse response)
     throws IOException {
-    final UserGroupInformation ugi = getUGI(request);
+    Configuration conf =
+	(Configuration) getServletContext().getAttribute("name.conf");
+    final UserGroupInformation ugi = getUGI(request, conf);
 
     try {
       final ClientProtocol nnproxy = ugi

src/hdfs/org/apache/hadoop/hdfs/server/namenode/FsckServlet.java

@@ -43,15 +43,14 @@ public class FsckServlet extends DfsServlet {
     @SuppressWarnings("unchecked")
     final Map<String,String[]> pmap = request.getParameterMap();
     final PrintWriter out = response.getWriter();
-
-    final UserGroupInformation ugi = getUGI(request);
+    final ServletContext context = getServletContext();
+    final Configuration conf = 
+      (Configuration) context.getAttribute("name.conf");
+    final UserGroupInformation ugi = getUGI(request, conf);
     try {
       ugi.doAs(new PrivilegedExceptionAction<Object>() {
         @Override
         public Object run() throws Exception {
-          final ServletContext context = getServletContext();
-          final Configuration conf = new Configuration((Configuration) context.getAttribute("name.conf"));
-
           final NameNode nn = (NameNode) context.getAttribute("name.node");
           final int totalDatanodes = nn.namesystem.getNumberOfDatanodes(DatanodeReportType.LIVE); 
           final short minReplication = nn.namesystem.getMinReplication();

src/hdfs/org/apache/hadoop/hdfs/server/namenode/JspHelper.java

@@ -22,6 +22,7 @@ import java.io.IOException;
 import java.io.UnsupportedEncodingException;
 import java.net.InetSocketAddress;
 import java.net.Socket;
+import java.security.PrivilegedExceptionAction;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Comparator;
@@ -31,30 +32,39 @@ import java.util.TreeSet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.jsp.JspWriter;
 
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hdfs.DFSClient;
 import org.apache.hadoop.hdfs.protocol.DatanodeID;
 import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
 import org.apache.hadoop.hdfs.protocol.LocatedBlock;
 import org.apache.hadoop.hdfs.protocol.FSConstants.UpgradeAction;
+import org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenIdentifier;
 import org.apache.hadoop.hdfs.server.common.HdfsConstants;
 import org.apache.hadoop.hdfs.server.common.UpgradeStatusReport;
 import org.apache.hadoop.hdfs.server.datanode.DataNode;
+import org.apache.hadoop.hdfs.server.namenode.DatanodeDescriptor;
+import org.apache.hadoop.hdfs.server.namenode.FSNamesystem;
 import org.apache.hadoop.http.HtmlQuoting;
 import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.security.AccessControlException;
+import org.apache.hadoop.security.UserGroupInformation;
+import org.apache.hadoop.security.token.Token;
 import org.apache.hadoop.util.StringUtils;
 import org.apache.hadoop.net.NetUtils;
 import org.apache.hadoop.hdfs.security.BlockAccessToken;
 
 public class JspHelper {
   final static public String WEB_UGI_PROPERTY_NAME = "dfs.web.ugi";
+  public static final String DELEGATION_PARAMETER_NAME = "delegation";
+  public static final String SET_DELEGATION = "&" + DELEGATION_PARAMETER_NAME +
+                                              "=";
+  private static final Log LOG = LogFactory.getLog(JspHelper.class);
 
   static FSNamesystem fsn = null;
   public static InetSocketAddress nameNodeAddr;
-  public static final Configuration conf = new Configuration();
   
-  public static final int defaultChunkSizeToView = 
-    conf.getInt("dfs.default.chunk.view.size", 32 * 1024);
   static Random rand = new Random();
 
   public JspHelper() {
@@ -111,8 +121,11 @@ public class JspHelper {
     return chosenNode;
   }
   public void streamBlockInAscii(InetSocketAddress addr, long blockId, 
-                                 BlockAccessToken accessToken, long genStamp, long blockSize, 
-                                 long offsetIntoBlock, long chunkSizeToView, JspWriter out) 
+                                 BlockAccessToken accessToken, long genStamp, 
+                                 long blockSize, 
+                                 long offsetIntoBlock, long chunkSizeToView, 
+                                 JspWriter out,
+                                 Configuration conf) 
     throws IOException {
     if (chunkSizeToView == 0) return;
     Socket s = new Socket();
@@ -332,7 +345,10 @@ public class JspHelper {
     Collections.sort(nodes, new NodeComapare(field, order));
   }
 
-  public static void printPathWithLinks(String dir, JspWriter out, int namenodeInfoPort ) throws IOException {
+  public static void printPathWithLinks(String dir, JspWriter out, 
+                                        int namenodeInfoPort,
+                                        String tokenString
+                                       ) throws IOException {
     try {
       String[] parts = dir.split(Path.SEPARATOR);
       StringBuilder tempPath = new StringBuilder(dir.length());
@@ -344,7 +360,8 @@ public class JspHelper {
         if (!parts[i].equals("")) {
           tempPath.append(parts[i]);
           out.print("<a href=\"browseDirectory.jsp" + "?dir="
-              + tempPath.toString() + "&namenodeInfoPort=" + namenodeInfoPort);
+              + tempPath.toString() + "&namenodeInfoPort=" + namenodeInfoPort
+              + SET_DELEGATION + tokenString);
           out.print("\">" + parts[i] + "</a>" + Path.SEPARATOR);
           tempPath.append(Path.SEPARATOR);
         }
@@ -358,22 +375,113 @@ public class JspHelper {
     }
   }
 
-  public static void printGotoForm(JspWriter out, int namenodeInfoPort, String file) throws IOException {
+  public static void printGotoForm(JspWriter out,
+                                   int namenodeInfoPort,
+                                   String tokenString,
+                                   String file) throws IOException {
     out.print("<form action=\"browseDirectory.jsp\" method=\"get\" name=\"goto\">");
     out.print("Goto : ");
     out.print("<input name=\"dir\" type=\"text\" width=\"50\" id\"dir\" value=\""+ file+"\">");
     out.print("<input name=\"go\" type=\"submit\" value=\"go\">");
     out.print("<input name=\"namenodeInfoPort\" type=\"hidden\" "
         + "value=\"" + namenodeInfoPort  + "\">");
+    out.print("<input name=\"" + DELEGATION_PARAMETER_NAME +
+              "\" type=\"hidden\" value=\"" + tokenString + "\">");
     out.print("</form>");
   }
   
   public static void createTitle(JspWriter out, 
-      HttpServletRequest req, String  file) throws IOException{
+                                 HttpServletRequest req, 
+                                 String  file) throws IOException{
     if(file == null) file = "";
     int start = Math.max(0,file.length() - 100);
     if(start != 0)
       file = "..." + file.substring(start, file.length());
     out.print("<title>HDFS:" + file + "</title>");
   }
+
+  
+  /**
+   * If security is turned off, what is the default web user?
+   * @param conf the configuration to look in
+   * @return the remote user that was configuration
+   */
+  public static UserGroupInformation getDefaultWebUser(Configuration conf
+                                                       ) throws IOException {
+    String[] strings = conf.getStrings(JspHelper.WEB_UGI_PROPERTY_NAME);
+    if (strings == null || strings.length == 0) {
+      throw new IOException("Cannot determine UGI from request or conf");
+    }
+    return UserGroupInformation.createRemoteUser(strings[0]);
+  }
+
+  /**
+   * Get {@link UserGroupInformation} and possibly the delegation token out of
+   * the request.
+   * @param request the http request
+   * @return a new user from the request
+   * @throws AccessControlException if the request has no token
+   */
+  public static UserGroupInformation getUGI(HttpServletRequest request,
+                                            Configuration conf
+                                           ) throws IOException {
+    UserGroupInformation ugi = null;
+    if(UserGroupInformation.isSecurityEnabled()) {
+      String user = request.getRemoteUser();
+      String tokenString = request.getParameter(DELEGATION_PARAMETER_NAME);
+      if (tokenString != null) {
+        Token<DelegationTokenIdentifier> token = 
+          new Token<DelegationTokenIdentifier>();
+        token.decodeFromUrlString(tokenString);
+        ugi = UserGroupInformation.createRemoteUser(user);
+        ugi.addToken(token);        
+      } else {
+        if(user == null) {
+          throw new IOException("Security enabled but user not " +
+                                "authenticated by filter");
+        }
+        ugi = UserGroupInformation.createRemoteUser(user);
+      }
+    } 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);
+      }
+    }
+    
+    if(LOG.isDebugEnabled())
+      LOG.debug("getUGI is returning: " + ugi.getShortUserName());
+    return ugi;
+  }
+
+  public static DFSClient getDFSClient(final UserGroupInformation user,
+                                       final InetSocketAddress addr,
+                                       final Configuration conf
+                                       ) throws IOException,
+                                                InterruptedException {
+    return
+      user.doAs(new PrivilegedExceptionAction<DFSClient>() {
+        public DFSClient run() throws IOException {
+          return new DFSClient(addr, conf);
+        }
+      });
+  }
+
+   /** Convert a String to chunk-size-to-view. */
+   public static int string2ChunkSizeToView(String s, int defaultValue) {
+     int n = s == null? 0: Integer.parseInt(s);
+     return n > 0? n: defaultValue;
+   }
+
+  /**
+   * Get the default chunk size.
+   * @param conf the configuration
+   * @return the number of bytes to chunk in
+   */
+  public static int getDefaultChunkSize(Configuration conf) {
+    return conf.getInt("dfs.default.chunk.view.size", 32 * 1024);
+  }
 }

src/hdfs/org/apache/hadoop/hdfs/server/namenode/ListPathsServlet.java

@@ -17,6 +17,7 @@
  */
 package org.apache.hadoop.hdfs.server.namenode;
 
+import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hdfs.HftpFileSystem;
 import org.apache.hadoop.hdfs.protocol.ClientProtocol;
@@ -134,9 +135,11 @@ public class ListPathsServlet extends DfsServlet {
       final boolean recur = "yes".equals(root.get("recursive"));
       final Pattern filter = Pattern.compile(root.get("filter"));
       final Pattern exclude = Pattern.compile(root.get("exclude"));
+      final Configuration conf = 
+        (Configuration) request.getAttribute("name.conf");
       
-      ClientProtocol nnproxy = 
-        getUGI(request).doAs(new PrivilegedExceptionAction<ClientProtocol>() {
+      ClientProtocol nnproxy = getUGI(request, conf).doAs
+        (new PrivilegedExceptionAction<ClientProtocol>() {
         @Override
         public ClientProtocol run() throws IOException {
           return createNameNodeProxy();

src/hdfs/org/apache/hadoop/hdfs/server/namenode/StreamFile.java

@@ -31,31 +31,16 @@ import org.apache.hadoop.conf.*;
 public class StreamFile extends DfsServlet {
   static InetSocketAddress nameNodeAddr;
   static DataNode datanode = null;
-  private static final Configuration masterConf = new Configuration();
   static {
     if ((datanode = DataNode.getDataNode()) != null) {
       nameNodeAddr = datanode.getNameNodeAddr();
     }
   }
   
-  /** getting a client for connecting to dfs */
-  protected DFSClient getDFSClient(HttpServletRequest request)
-      throws IOException, InterruptedException {
-    final Configuration conf = new Configuration(masterConf);
-
-    DFSClient client = 
-      getUGI(request).doAs(new PrivilegedExceptionAction<DFSClient>() {
-      @Override
-      public DFSClient run() throws IOException {
-        return new DFSClient(nameNodeAddr, conf);
-      }
-    });
-
-    return client;
-  }
-  
   public void doGet(HttpServletRequest request, HttpServletResponse response)
     throws ServletException, IOException {
+    Configuration conf = 
+      (Configuration) getServletContext().getAttribute("name.conf");
     String filename = request.getParameter("filename");
     if (filename == null || filename.length() == 0) {
       response.setContentType("text/plain");
@@ -65,8 +50,9 @@ public class StreamFile extends DfsServlet {
     }
     
     DFSClient dfs;
+    UserGroupInformation ugi = getUGI(request, conf);
     try {
-      dfs = getDFSClient(request);
+	dfs = JspHelper.getDFSClient(ugi, nameNodeAddr, conf);
     } catch (InterruptedException e) {
       response.sendError(400, e.getMessage());
       return;

src/test/findbugsExcludeFile.xml

@@ -32,6 +32,16 @@
        <Field name="out" />
        <Bug pattern="IS2_INCONSISTENT_SYNC" />
      </Match>
+     <!-- 
+       Ignore Cross Scripting Vulnerabilities
+       We have an input quoting filter that protects us.
+     -->
+     <Match>
+       <Bug code="XSS" />
+     </Match>
+     <Match>
+       <Bug code="HRS" />
+     </Match>
      <!-- 
        Accesses to Client.Connection.saslRpcClient are in fact
        synchronized (inside synchronized methods).

src/webapps/datanode/browseBlock.jsp

@@ -8,12 +8,14 @@
   import="org.apache.hadoop.hdfs.*"
   import="org.apache.hadoop.hdfs.server.namenode.*"
   import="org.apache.hadoop.hdfs.server.datanode.*"
+  import="org.apache.hadoop.hdfs.server.common.*"
   import="org.apache.hadoop.hdfs.protocol.*"
   import="org.apache.hadoop.io.*"
   import="org.apache.hadoop.conf.*"
   import="org.apache.hadoop.net.DNS"
   import="org.apache.hadoop.hdfs.security.BlockAccessToken"
   import="org.apache.hadoop.hdfs.security.AccessTokenHandler"
+  import="org.apache.hadoop.security.UserGroupInformation"
   import="org.apache.hadoop.util.*"
   import="java.text.DateFormat"
 %>
@@ -21,8 +23,9 @@
 <%!
   static JspHelper jspHelper = new JspHelper();
 
-  public void generateFileDetails(JspWriter out, HttpServletRequest req) 
-    throws IOException {
+  public void generateFileDetails(JspWriter out, HttpServletRequest req,
+                                  Configuration conf
+                                 ) throws IOException, InterruptedException {
 
     int chunkSizeToView = 0;
     long startOffset = 0;
@@ -50,9 +53,12 @@
       namenodeInfoPort = Integer.parseInt(namenodeInfoPortStr);
 
     String chunkSizeToViewStr = req.getParameter("chunkSizeToView");
-    if (chunkSizeToViewStr != null && Integer.parseInt(chunkSizeToViewStr) > 0)
-      chunkSizeToView = Integer.parseInt(chunkSizeToViewStr);
-    else chunkSizeToView = jspHelper.defaultChunkSizeToView;
+    if (chunkSizeToViewStr != null && 
+        Integer.parseInt(chunkSizeToViewStr) > 0) {
+     chunkSizeToView = Integer.parseInt(chunkSizeToViewStr);
+    } else {
+     chunkSizeToView = JspHelper.getDefaultChunkSize(conf);
+    }
 
     String startOffsetStr = req.getParameter("startOffset");
     if (startOffsetStr == null || Long.parseLong(startOffsetStr) < 0)
@@ -73,14 +79,17 @@
     } 
     blockSize = Long.parseLong(blockSizeStr);
 
-    DFSClient dfs = new DFSClient(jspHelper.nameNodeAddr, jspHelper.conf);
+    String tokenString = req.getParameter(JspHelper.DELEGATION_PARAMETER_NAME);
+    UserGroupInformation ugi = JspHelper.getUGI(req, conf);
+    DFSClient dfs = JspHelper.getDFSClient(ugi, jspHelper.nameNodeAddr, conf);
     List<LocatedBlock> blocks = 
       dfs.namenode.getBlockLocations(filename, 0, Long.MAX_VALUE).getLocatedBlocks();
     //Add the various links for looking at the file contents
     //URL for downloading the full file
     String downloadUrl = "http://" + req.getServerName() + ":" +
-                         + req.getServerPort() + "/streamFile?" + "filename=" +
-                         URLEncoder.encode(filename, "UTF-8");
+                         + req.getServerPort() + "/streamFile?" + "filename="
+                         + URLEncoder.encode(filename, "UTF-8")
+                         + JspHelper.SET_DELEGATION + tokenString;
     out.print("<a name=\"viewOptions\"></a>");
     out.print("<a href=\"" + downloadUrl + "\">Download this file</a><br>");
     
@@ -104,7 +113,8 @@
                  "&chunkSizeToView=" + chunkSizeToView +
                  "&referrer=" + 
           URLEncoder.encode(req.getRequestURL() + "?" + req.getQueryString(),
-                            "UTF-8");
+                            "UTF-8") +
+                 JspHelper.SET_DELEGATION + tokenString;
     out.print("<a href=\"" + tailUrl + "\">Tail this file</a><br>");
 
     out.print("<form action=\"/browseBlock.jsp\" method=GET>");
@@ -166,8 +176,9 @@
     dfs.close();
   }
 
-  public void generateFileChunks(JspWriter out, HttpServletRequest req) 
-    throws IOException {
+  public void generateFileChunks(JspWriter out, HttpServletRequest req,
+                                 Configuration conf
+                                ) throws IOException, InterruptedException {
     long startOffset = 0;
     int datanodePort = 0; 
     int chunkSizeToView = 0;
@@ -192,11 +203,13 @@
     }
     blockId = Long.parseLong(blockIdStr);
 
-    final DFSClient dfs = new DFSClient(jspHelper.nameNodeAddr, jspHelper.conf);
+    String tokenString = req.getParameter(JspHelper.DELEGATION_PARAMETER_NAME);
+    UserGroupInformation ugi = JspHelper.getUGI(req, conf);
+    final DFSClient dfs = JspHelper.getDFSClient(ugi, jspHelper.nameNodeAddr,
+                                                 conf);
     
     BlockAccessToken accessToken = BlockAccessToken.DUMMY_TOKEN;
-    if (JspHelper.conf
-        .getBoolean(AccessTokenHandler.STRING_ENABLE_ACCESS_TOKEN, false)) {
+    if (conf.getBoolean(AccessTokenHandler.STRING_ENABLE_ACCESS_TOKEN, false)){
       List<LocatedBlock> blks = dfs.namenode.getBlockLocations(filename, 0,
           Long.MAX_VALUE).getLocatedBlocks();
       if (blks == null || blks.size() == 0) {
@@ -233,7 +246,7 @@
     String chunkSizeToViewStr = req.getParameter("chunkSizeToView");
     if (chunkSizeToViewStr != null && Integer.parseInt(chunkSizeToViewStr) > 0)
       chunkSizeToView = Integer.parseInt(chunkSizeToViewStr);
-    else chunkSizeToView = jspHelper.defaultChunkSizeToView;
+    else chunkSizeToView = JspHelper.getDefaultChunkSize(conf);
 
     String startOffsetStr = req.getParameter("startOffset");
     if (startOffsetStr == null || Long.parseLong(startOffsetStr) < 0)
@@ -247,10 +260,11 @@
     }
     datanodePort = Integer.parseInt(datanodePortStr);
     out.print("<h3>File: ");
-    JspHelper.printPathWithLinks(filename, out, namenodeInfoPort);
+    JspHelper.printPathWithLinks(filename, out, namenodeInfoPort,
+                                 tokenString);
     out.print("</h3><hr>");
     String parent = new File(filename).getParent();
-    JspHelper.printGotoForm(out, namenodeInfoPort, parent);
+    JspHelper.printGotoForm(out, namenodeInfoPort, tokenString, parent);
     out.print("<hr>");
     out.print("<a href=\"http://" + req.getServerName() + ":" + 
               req.getServerPort() + 
@@ -312,7 +326,8 @@
                 "&filename=" + URLEncoder.encode(filename, "UTF-8") +
                 "&chunkSizeToView=" + chunkSizeToView + 
                 "&datanodePort=" + nextDatanodePort +
-                "&namenodeInfoPort=" + namenodeInfoPort;
+                "&namenodeInfoPort=" + namenodeInfoPort +
+                JspHelper.SET_DELEGATION + tokenString;
       out.print("<a href=\"" + nextUrl + "\">View Next chunk</a>&nbsp;&nbsp;");        
     }
     //determine data for the prev link
@@ -368,7 +383,8 @@
                 "&chunkSizeToView=" + chunkSizeToView +
                 "&genstamp=" + prevGenStamp +
                 "&datanodePort=" + prevDatanodePort +
-                "&namenodeInfoPort=" + namenodeInfoPort;
+                "&namenodeInfoPort=" + namenodeInfoPort +
+                JspHelper.SET_DELEGATION + tokenString;
       out.print("<a href=\"" + prevUrl + "\">View Prev chunk</a>&nbsp;&nbsp;");
     }
     out.print("<hr>");
@@ -376,7 +392,8 @@
     try {
     jspHelper.streamBlockInAscii(
             new InetSocketAddress(req.getServerName(), datanodePort), blockId, 
-            accessToken, genStamp, blockSize, startOffset, chunkSizeToView, out);
+            accessToken, genStamp, blockSize, startOffset, chunkSizeToView, 
+            out, conf);
     } catch (Exception e){
         out.print(e);
     }
@@ -391,11 +408,13 @@
 </head>
 <body onload="document.goto.dir.focus()">
 <% 
-   generateFileChunks(out,request);
+   Configuration conf = 
+     (Configuration) getServletContext().getAttribute("datanode.conf");
+   generateFileChunks(out, request, conf);
 %>
 <hr>
 <% 
-   generateFileDetails(out,request);
+   generateFileDetails(out, request, conf);
 %>
 
 <h2>Local logs</h2>

src/webapps/datanode/browseDirectory.jsp

@@ -5,14 +5,17 @@
   import="java.io.*"
   import="java.util.*"
   import="java.net.*"
+  import="org.apache.hadoop.conf.Configuration"
   import="org.apache.hadoop.fs.*"
   import="org.apache.hadoop.hdfs.*"
   import="org.apache.hadoop.hdfs.server.namenode.*"
   import="org.apache.hadoop.hdfs.server.datanode.*"
+  import="org.apache.hadoop.hdfs.server.common.*"
   import="org.apache.hadoop.hdfs.protocol.*"
   import="org.apache.hadoop.io.*"
   import="org.apache.hadoop.conf.*"
   import="org.apache.hadoop.net.DNS"
+  import="org.apache.hadoop.security.UserGroupInformation"
   import="org.apache.hadoop.util.*"
   import="java.text.DateFormat"
 %>
@@ -21,24 +24,29 @@
   
   public void generateDirectoryStructure( JspWriter out, 
                                           HttpServletRequest req,
-                                          HttpServletResponse resp) 
-    throws IOException {
+                                          HttpServletResponse resp,
+                                          Configuration conf
+                                         ) throws IOException, 
+                                                  InterruptedException {
     String dir = req.getParameter("dir");
     if (dir == null || dir.length() == 0) {
       out.print("Invalid input");
       return;
     }
     
+    String tokenString = req.getParameter(JspHelper.DELEGATION_PARAMETER_NAME);
+    UserGroupInformation ugi = JspHelper.getUGI(req, conf);
     String namenodeInfoPortStr = req.getParameter("namenodeInfoPort");
     int namenodeInfoPort = -1;
     if (namenodeInfoPortStr != null)
       namenodeInfoPort = Integer.parseInt(namenodeInfoPortStr);
     
-    DFSClient dfs = new DFSClient(jspHelper.nameNodeAddr, jspHelper.conf);
+    DFSClient dfs = JspHelper.getDFSClient(ugi, jspHelper.nameNodeAddr, 
+                                           conf);
     String target = dir;
     if (!dfs.exists(target)) {
       out.print("<h3>File or directory : " + target + " does not exist</h3>");
-      JspHelper.printGotoForm(out, namenodeInfoPort, target);
+      JspHelper.printGotoForm(out, namenodeInfoPort, tokenString, target);
     }
     else {
       if( !dfs.isDirectory(target) ) { // a file
@@ -69,8 +77,9 @@
             "&blockSize=" + firstBlock.getBlock().getNumBytes() +
             "&genstamp=" + firstBlock.getBlock().getGenerationStamp() +
             "&filename=" + URLEncoder.encode(dir, "UTF-8") + 
-            "&datanodePort=" + datanodePort + 
-            "&namenodeInfoPort=" + namenodeInfoPort;
+            "&datanodePort="
+            + datanodePort + "&namenodeInfoPort=" + namenodeInfoPort
+            + JspHelper.SET_DELEGATION + tokenString;
           resp.sendRedirect(redirectLocation);
         }
         return;
@@ -81,9 +90,9 @@
                               "Block Size", "Modification Time",
                               "Permission", "Owner", "Group" };
       out.print("<h3>Contents of directory ");
-      JspHelper.printPathWithLinks(dir, out, namenodeInfoPort);
+      JspHelper.printPathWithLinks(dir, out, namenodeInfoPort, tokenString);
       out.print("</h3><hr>");
-      JspHelper.printGotoForm(out, namenodeInfoPort, dir);
+      JspHelper.printGotoForm(out, namenodeInfoPort, tokenString, dir);
       out.print("<hr>");
 	
       File f = new File(dir);
@@ -91,6 +100,7 @@
       if ((parent = f.getParent()) != null)
         out.print("<a href=\"" + req.getRequestURL() + "?dir=" + parent +
                   "&namenodeInfoPort=" + namenodeInfoPort +
+                  JspHelper.SET_DELEGATION + tokenString +
                   "\">Go to parent directory</a><br>");
 
       DirectoryListing thisListing;
@@ -165,8 +175,10 @@ body
 
 <body onload="document.goto.dir.focus()">
 <% 
+  Configuration conf = 
+    (Configuration) getServletContext().getAttribute("datanode.conf");
   try {
-    generateDirectoryStructure(out,request,response);
+    generateDirectoryStructure(out,request,response,conf);
   }
   catch(IOException ioe) {
     String msg = ioe.getLocalizedMessage();

src/webapps/datanode/tail.jsp

@@ -8,6 +8,7 @@
   import="org.apache.hadoop.hdfs.*"
   import="org.apache.hadoop.hdfs.server.namenode.*"
   import="org.apache.hadoop.hdfs.server.datanode.*"
+  import="org.apache.hadoop.hdfs.server.common.*"
   import="org.apache.hadoop.hdfs.protocol.*"
   import="org.apache.hadoop.io.*"
   import="org.apache.hadoop.conf.*"
@@ -15,18 +16,20 @@
   import="org.apache.hadoop.hdfs.security.BlockAccessToken"
   import="org.apache.hadoop.util.*"
   import="org.apache.hadoop.net.NetUtils"
+  import="org.apache.hadoop.security.UserGroupInformation"
   import="java.text.DateFormat"
 %>
 
 <%!
-  static JspHelper jspHelper = new JspHelper();
+  JspHelper jspHelper = new JspHelper();
 
-  public void generateFileChunks(JspWriter out, HttpServletRequest req) 
-    throws IOException {
+  public void generateFileChunks(JspWriter out, HttpServletRequest req,
+                                 Configuration conf
+                                ) throws IOException, InterruptedException {
     long startOffset = 0;
     
     int chunkSizeToView = 0;
-
+    String tokenString = req.getParameter(JspHelper.DELEGATION_PARAMETER_NAME);
     String referrer = req.getParameter("referrer");
     boolean noLink = false;
     if (referrer == null) {
@@ -47,11 +50,12 @@
     String chunkSizeToViewStr = req.getParameter("chunkSizeToView");
     if (chunkSizeToViewStr != null && Integer.parseInt(chunkSizeToViewStr) > 0)
       chunkSizeToView = Integer.parseInt(chunkSizeToViewStr);
-    else chunkSizeToView = jspHelper.defaultChunkSizeToView;
+    else chunkSizeToView = JspHelper.getDefaultChunkSize(conf);
 
     if (!noLink) {
       out.print("<h3>Tail of File: ");
-      JspHelper.printPathWithLinks(filename, out, namenodeInfoPort);
+      JspHelper.printPathWithLinks(filename, out, namenodeInfoPort, 
+                                   tokenString);
 	    out.print("</h3><hr>");
       out.print("<a href=\"" + referrer + "\">Go Back to File View</a><hr>");
     }
@@ -71,10 +75,11 @@
                 referrer+ "\">");
 
     //fetch the block from the datanode that has the last block for this file
-    DFSClient dfs = new DFSClient(jspHelper.nameNodeAddr, 
-                                         jspHelper.conf);
+    UserGroupInformation ugi = JspHelper.getUGI(req, conf);
+    DFSClient dfs = JspHelper.getDFSClient(ugi, jspHelper.nameNodeAddr, conf);
     List<LocatedBlock> blocks = 
-      dfs.namenode.getBlockLocations(filename, 0, Long.MAX_VALUE).getLocatedBlocks();
+      dfs.namenode.getBlockLocations(filename, 0, Long.MAX_VALUE
+                                     ).getLocatedBlocks();
     if (blocks == null || blocks.size() == 0) {
       out.print("No datanodes contain blocks of file "+filename);
       dfs.close();
@@ -100,7 +105,9 @@
     else startOffset = 0;
 
     out.print("<textarea cols=\"100\" rows=\"25\" wrap=\"virtual\" style=\"width:100%\" READONLY>");
-    jspHelper.streamBlockInAscii(addr, blockId, accessToken, genStamp, blockSize, startOffset, chunkSizeToView, out);
+    jspHelper.streamBlockInAscii(addr, blockId, accessToken, genStamp, 
+                                 blockSize, startOffset, chunkSizeToView, 
+                                 out, conf);
     out.print("</textarea>");
     dfs.close();
   }
@@ -116,7 +123,9 @@
 <body>
 <form action="/tail.jsp" method="GET">
 <% 
-   generateFileChunks(out,request);
+   Configuration conf = 
+     (Configuration) application.getAttribute("datanode.conf");
+   generateFileChunks(out, request, conf);
 %>
 </form>
 <hr>

src/webapps/hdfs/nn_browsedfscontent.jsp

@@ -1,29 +1,56 @@
 <%@ page
   contentType="text/html; charset=UTF-8"
-  import="javax.servlet.*"
-  import="javax.servlet.http.*"
   import="java.io.*"
+  import="java.security.PrivilegedExceptionAction"
   import="java.util.*"
+  import="javax.servlet.*"
+  import="javax.servlet.http.*"
+  import="org.apache.hadoop.conf.Configuration"
   import="org.apache.hadoop.hdfs.*"
   import="org.apache.hadoop.hdfs.server.namenode.*"
   import="org.apache.hadoop.hdfs.server.datanode.*"
   import="org.apache.hadoop.hdfs.protocol.*"
+  import="org.apache.hadoop.hdfs.security.token.delegation.*"
+  import="org.apache.hadoop.io.Text"
+  import="org.apache.hadoop.security.UserGroupInformation"
+  import="org.apache.hadoop.security.token.Token"
   import="org.apache.hadoop.util.*"
   import="java.text.DateFormat"
   import="java.net.InetAddress"
   import="java.net.URLEncoder"
 %>
 <%!
+  static String getDelegationToken(final NameNode nn, final String user
+                                   ) throws IOException, InterruptedException {
+    if (user == null) {
+      return null;
+    }
+    UserGroupInformation ugi = UserGroupInformation.createRemoteUser(user);
+    Token<DelegationTokenIdentifier> token =
+      ugi.doAs(
+              new PrivilegedExceptionAction<Token<DelegationTokenIdentifier>>()
+          {
+            public Token<DelegationTokenIdentifier> run() throws IOException {
+              return nn.getDelegationToken(new Text(user));
+            }
+          });
+    return token.encodeToUrlString();
+  }
+
   public void redirectToRandomDataNode(
                             NameNode nn, 
-                            HttpServletResponse resp) throws IOException {
+                            HttpServletRequest request,
+                            HttpServletResponse resp
+                           ) throws IOException, InterruptedException {
+    String tokenString = getDelegationToken(nn, request.getRemoteUser());
     FSNamesystem fsn = nn.getNamesystem();
     String datanode = fsn.randomDataNode();
     String redirectLocation;
     String nodeToRedirect;
     int redirectPort;
     if (datanode != null) {
-      redirectPort = Integer.parseInt(datanode.substring(datanode.indexOf(':') + 1));
+      redirectPort = Integer.parseInt(datanode.substring(datanode.indexOf(':')
+                     + 1));
       nodeToRedirect = datanode.substring(0, datanode.indexOf(':'));
     }
     else {
@@ -34,7 +61,9 @@
     redirectLocation = "http://" + fqdn + ":" + redirectPort + 
                        "/browseDirectory.jsp?namenodeInfoPort=" + 
                        nn.getHttpAddress().getPort() +
-                       "&dir=" + URLEncoder.encode("/", "UTF-8");
+                       "&dir=/" + 
+                       (tokenString == null ? "" :
+                        JspHelper.SET_DELEGATION + tokenString);
     resp.sendRedirect(redirectLocation);
   }
 %>
@@ -46,7 +75,8 @@
 <body>
 <% 
   NameNode nn = (NameNode)application.getAttribute("name.node");
-  redirectToRandomDataNode(nn, response); 
+  Configuration conf = (Configuration) application.getAttribute("name.conf");
+  redirectToRandomDataNode(nn, request, response); 
 %>
 <hr>