From 73b195ecccddeec326e8e358569de56a78ebd71d Mon Sep 17 00:00:00 2001
From: Allen Wittenauer <aw@apache.org>
Date: Tue, 9 Feb 2016 14:15:21 -0800
Subject: [PATCH] HDFS-9760. WebHDFS AuthFilter cannot be configured with
 custom AltKerberos auth handler (Ryan Sasson via aw)

---
 hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt       |  3 +++
 .../hdfs/server/namenode/NameNodeHttpServer.java  | 11 +++++++++++
 .../org/apache/hadoop/hdfs/web/AuthFilter.java    | 10 ++++++----
 .../apache/hadoop/hdfs/web/TestAuthFilter.java    | 15 +++++++++++++++
 4 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
index 67f69fc38ad..71445d0c44f 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@@ -1808,6 +1808,9 @@ Release 2.8.0 - UNRELEASED
     HDFS-9713. DataXceiver#copyBlock should return if block is pinned.
     (umamahesh)
 
+    HDFS-9760. WebHDFS AuthFilter cannot be configured with custom AltKerberos
+    auth handler (Ryan Sasson via aw)
+
 Release 2.7.3 - UNRELEASED
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNodeHttpServer.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNodeHttpServer.java
index b8ddef9adad..5fa147e1d85 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNodeHttpServer.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNodeHttpServer.java
@@ -21,7 +21,9 @@ package org.apache.hadoop.hdfs.server.namenode;
 import java.io.IOException;
 import java.net.InetSocketAddress;
 import java.util.HashMap;
+import java.util.Iterator;
 import java.util.Map;
+import java.util.Map.Entry;
 
 import javax.servlet.ServletContext;
 
@@ -33,6 +35,7 @@ import org.apache.hadoop.hdfs.security.token.delegation.DelegationUtilsClient;
 import org.apache.hadoop.hdfs.server.common.JspHelper;
 import org.apache.hadoop.hdfs.server.namenode.startupprogress.StartupProgress;
 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.hdfs.web.resources.UserParam;
@@ -159,6 +162,14 @@ public class NameNodeHttpServer {
   private Map<String, String> getAuthFilterParams(Configuration conf)
       throws IOException {
     Map<String, String> params = new HashMap<String, String>();
+    // Select configs beginning with 'dfs.web.authentication.'
+    Iterator<Map.Entry<String, String>> iterator = conf.iterator();
+    while (iterator.hasNext()) {
+      Entry<String, String> kvPair = iterator.next();
+      if (kvPair.getKey().startsWith(AuthFilter.CONF_PREFIX)) {
+        params.put(kvPair.getKey(), kvPair.getValue());
+      }
+    }
     String principalInConf = conf
         .get(DFSConfigKeys.DFS_WEB_AUTHENTICATION_KERBEROS_PRINCIPAL_KEY);
     if (principalInConf != null && !principalInConf.isEmpty()) {
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/AuthFilter.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/AuthFilter.java
index 5ad1f2464ed..a8b7bd434b8 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/AuthFilter.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/AuthFilter.java
@@ -46,7 +46,7 @@ import org.apache.hadoop.util.StringUtils;
  * obtains Hadoop-Auth configuration for webhdfs.
  */
 public class AuthFilter extends AuthenticationFilter {
-  private static final String CONF_PREFIX = "dfs.web.authentication.";
+  public static final String CONF_PREFIX = "dfs.web.authentication.";
 
   /**
    * Returns the filter configuration properties,
@@ -62,9 +62,11 @@ public class AuthFilter extends AuthenticationFilter {
   protected Properties getConfiguration(String prefix, FilterConfig config)
       throws ServletException {
     final Properties p = super.getConfiguration(CONF_PREFIX, config);
-    // set authentication type
-    p.setProperty(AUTH_TYPE, UserGroupInformation.isSecurityEnabled()?
-        KerberosAuthenticationHandler.TYPE: PseudoAuthenticationHandler.TYPE);
+    // if not set, configure based on security enabled
+    if (p.getProperty(AUTH_TYPE) == null) {
+      p.setProperty(AUTH_TYPE, UserGroupInformation.isSecurityEnabled()?
+          KerberosAuthenticationHandler.TYPE: PseudoAuthenticationHandler.TYPE);
+    }
     // if not set, enable anonymous for pseudo authentication
     if (p.getProperty(PseudoAuthenticationHandler.ANONYMOUS_ALLOWED) == null) {
       p.setProperty(PseudoAuthenticationHandler.ANONYMOUS_ALLOWED, "true");
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/web/TestAuthFilter.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/web/TestAuthFilter.java
index b19a08a2d35..98184618088 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/web/TestAuthFilter.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/web/TestAuthFilter.java
@@ -98,4 +98,19 @@ public class TestAuthFilter {
     Assert.assertEquals("true",
         p.getProperty(PseudoAuthenticationHandler.ANONYMOUS_ALLOWED));
   }
+
+  @Test
+  public void testGetCustomAuthConfiguration() throws ServletException {
+    AuthFilter filter = new AuthFilter();
+    Map<String, String> m = new HashMap<String,String>();
+
+    m.put(AuthFilter.CONF_PREFIX + AuthFilter.AUTH_TYPE, "com.yourclass");
+    m.put(AuthFilter.CONF_PREFIX + "alt-kerberos.param", "value");
+    FilterConfig config = new DummyFilterConfig(m);
+
+    Properties p = filter.getConfiguration(AuthFilter.CONF_PREFIX, config);
+    Assert.assertEquals("com.yourclass", p.getProperty(AuthFilter.AUTH_TYPE));
+    Assert.assertEquals("value", p.getProperty("alt-kerberos.param"));
+  }
+
 }