Revert "HADOOP-13081. add the ability to create multiple UGIs/subjects from one kerberos login. Contributed by Sergey Shelukhin."

This reverts commit 06df0cd87f5517e778cf0d97614035e126e2fb80.

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/UserGroupInformation.java

@@ -35,7 +35,6 @@ import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
-import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
@@ -628,33 +627,7 @@ public class UserGroupInformation {
     }
     this.isKrbTkt = KerberosUtil.hasKerberosTicket(subject);
   }
-
-  /**
-   * Copies the Subject of this UGI and creates a new UGI with the new subject.
-   * This can be used to add credentials (e.g. tokens) to different copies of
-   * the same UGI, allowing multiple users with different tokens to reuse the
-   * UGI without re-authenticating with Kerberos.
-   * @return clone of the UGI with a new subject.
-   */
-  @InterfaceAudience.Public
-  @InterfaceStability.Evolving
-  public UserGroupInformation copySubjectAndUgi() {
-    Subject subj = getSubject();
-    // The ctor will set other fields automatically from the principals.
-    return new UserGroupInformation(new Subject(false, subj.getPrincipals(),
-        cloneCredentials(subj.getPublicCredentials()),
-        cloneCredentials(subj.getPrivateCredentials())));
-  }
-
-  private static Set<Object> cloneCredentials(Set<Object> old) {
-    Set<Object> set = new HashSet<>();
-    // Make sure Hadoop credentials objects do not reuse the maps.
-    for (Object o : old) {
-      set.add(o instanceof Credentials ? new Credentials((Credentials)o) : o);
-    }
-    return set;
-  }
-
+  
   /**
    * checks if logged in using kerberos
    * @return true if the subject logged via keytab or has a Kerberos TGT

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/security/TestUserGroupInformation.java

@@ -42,7 +42,6 @@ import java.security.PrivilegedExceptionAction;
 import java.util.Collection;
 import java.util.ConcurrentModificationException;
 import java.util.LinkedHashSet;
-import java.util.List;
 import java.util.Set;
 
 import static org.apache.hadoop.fs.CommonConfigurationKeys.HADOOP_USER_GROUP_METRICS_PERCENTILES_INTERVALS;
@@ -841,32 +840,6 @@ public class TestUserGroupInformation {
     assertEquals(1, tokens.size());
   }
 
-  @Test(timeout = 30000)
-  public void testCopySubjectAndUgi() throws IOException {
-    SecurityUtil.setAuthenticationMethod(AuthenticationMethod.SIMPLE, conf);
-    UserGroupInformation.setConfiguration(conf);
-    UserGroupInformation u1 = UserGroupInformation.getLoginUser();
-    assertNotNull(u1);
-    @SuppressWarnings("unchecked")
-    Token<? extends TokenIdentifier> tmpToken = mock(Token.class);
-    u1.addToken(tmpToken);
-
-    UserGroupInformation u2 = u1.copySubjectAndUgi();
-    assertEquals(u1.getAuthenticationMethod(), u2.getAuthenticationMethod());
-    assertNotSame(u1.getSubject(), u2.getSubject());
-    Credentials c1 = u1.getCredentials(), c2 = u2.getCredentials();
-    List<Text> sc1 = c1.getAllSecretKeys(), sc2 = c2.getAllSecretKeys();
-    assertArrayEquals(sc1.toArray(new Text[0]), sc2.toArray(new Text[0]));
-    Collection<Token<? extends TokenIdentifier>> ts1 = c1.getAllTokens(),
-        ts2 = c2.getAllTokens();
-    assertArrayEquals(ts1.toArray(new Token[0]), ts2.toArray(new Token[0]));
-    @SuppressWarnings("unchecked")
-    Token<? extends TokenIdentifier> token = mock(Token.class);
-    u2.addToken(token);
-    assertTrue(u2.getCredentials().getAllTokens().contains(token));
-    assertFalse(u1.getCredentials().getAllTokens().contains(token));
-  }
-
   /**
    * This test checks a race condition between getting and adding tokens for
    * the current user.  Calling UserGroupInformation.getCurrentUser() returns