HADOOP-11482. Use correct UGI when KMSClientProvider is called by a proxy user. Contributed by Arun Suresh.

(cherry picked from commit 4b00935643f6c3656ccbd7eeb54884738bc12c2e)
(cherry picked from commit 7b69719455a1a374c9417417ef0c8d7ba6bf593f)

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -33,6 +33,9 @@ Release 2.6.1 - UNRELEASED
     HADOOP-11350. The size of header buffer of HttpServer is too small when
     HTTPS is enabled. (Benoy Antony via wheat9)
 
+    HADOOP-11482. Use correct UGI when KMSClientProvider is called by a proxy
+    user. Contributed by Arun Suresh.
+
 Release 2.6.0 - 2014-11-18
 
   INCOMPATIBLE CHANGES

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/crypto/key/kms/KMSClientProvider.java

@@ -773,25 +773,44 @@ public class KMSClientProvider extends KeyProvider implements CryptoExtension,
   }
 
   @Override
-  public Token<?>[] addDelegationTokens(String renewer,
+  public Token<?>[] addDelegationTokens(final String renewer,
       Credentials credentials) throws IOException {
     Token<?>[] tokens = null;
     Text dtService = getDelegationTokenService();
     Token<?> token = credentials.getToken(dtService);
     if (token == null) {
-      URL url = createURL(null, null, null, null);
-      DelegationTokenAuthenticatedURL authUrl =
+      final URL url = createURL(null, null, null, null);
+      final DelegationTokenAuthenticatedURL authUrl =
           new DelegationTokenAuthenticatedURL(configurator);
       try {
-        token = authUrl.getDelegationToken(url, authToken, renewer);
+        // 'actualUGI' is the UGI of the user creating the client 
+        // It is possible that the creator of the KMSClientProvier
+        // calls this method on behalf of a proxyUser (the doAsUser).
+        // In which case this call has to be made as the proxy user.
+        UserGroupInformation currentUgi = UserGroupInformation.getCurrentUser();
+        final String doAsUser = (currentUgi.getAuthenticationMethod() ==
+            UserGroupInformation.AuthenticationMethod.PROXY)
+                                ? currentUgi.getShortUserName() : null;
+
+        token = actualUgi.doAs(new PrivilegedExceptionAction<Token<?>>() {
+          @Override
+          public Token<?> run() throws Exception {
+            // Not using the cached token here.. Creating a new token here
+            // everytime.
+            return authUrl.getDelegationToken(url,
+                new DelegationTokenAuthenticatedURL.Token(), renewer, doAsUser);
+          }
+        });
         if (token != null) {
           credentials.addToken(token.getService(), token);
           tokens = new Token<?>[] { token };
         } else {
           throw new IOException("Got NULL as delegation token");
         }
-      } catch (AuthenticationException ex) {
-        throw new IOException(ex);
+      } catch (InterruptedException e) {
+        Thread.currentThread().interrupt();
+      } catch (Exception e) {
+        throw new IOException(e);
       }
     }
     return tokens;

hadoop-common-project/hadoop-kms/src/test/java/org/apache/hadoop/crypto/key/kms/server/TestKMS.java

@@ -287,6 +287,7 @@ public class TestKMS {
       password = null;
     }
 
+    conf.set("hadoop.kms.authentication.token.validity", "1");
     if (kerberos) {
       conf.set("hadoop.kms.authentication.type", "kerberos");
       conf.set("hadoop.kms.authentication.kerberos.keytab",
@@ -340,6 +341,11 @@ public class TestKMS {
                 final KeyProvider kp = new KMSClientProvider(uri, conf);
                 // getKeys() empty
                 Assert.assertTrue(kp.getKeys().isEmpty());
+
+                Thread.sleep(4000);
+                Token<?>[] tokens = ((KMSClientProvider)kp).addDelegationTokens("myuser", new Credentials());
+                Assert.assertEquals(1, tokens.length);
+                Assert.assertEquals("kms-dt", tokens[0].getKind().toString());
                 return null;
               }
             });
@@ -349,6 +355,7 @@ public class TestKMS {
           // getKeys() empty
           Assert.assertTrue(kp.getKeys().isEmpty());
 
+          Thread.sleep(4000);
           Token<?>[] tokens = ((KMSClientProvider)kp).addDelegationTokens("myuser", new Credentials());
           Assert.assertEquals(1, tokens.length);
           Assert.assertEquals("kms-dt", tokens[0].getKind().toString());