/**
 * 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.security;



import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;

import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.IOException;
import java.net.URI;
import java.security.PrivilegedExceptionAction;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.commons.logging.impl.Log4JLogger;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.DFSConfigKeys;
import org.apache.hadoop.hdfs.DFSTestUtil;
import org.apache.hadoop.hdfs.DistributedFileSystem;
import org.apache.hadoop.hdfs.HdfsConfiguration;
import org.apache.hadoop.hdfs.MiniDFSCluster;
import org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenIdentifier;
import org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenSecretManager;
import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.StartupOption;
import org.apache.hadoop.hdfs.server.namenode.NameNode;
import org.apache.hadoop.hdfs.server.namenode.NameNodeAdapter;
import org.apache.hadoop.hdfs.server.namenode.web.resources.NamenodeWebHdfsMethods;
import org.apache.hadoop.hdfs.web.WebHdfsConstants;
import org.apache.hadoop.hdfs.web.WebHdfsFileSystem;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.security.AccessControlException;
import org.apache.hadoop.security.Credentials;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.hadoop.security.token.SecretManager.InvalidToken;
import org.apache.hadoop.security.token.Token;
import org.apache.log4j.Level;
import org.junit.After;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;

public class TestDelegationToken {
  private MiniDFSCluster cluster;
  private DelegationTokenSecretManager dtSecretManager;
  private Configuration config;
  private static final Log LOG = LogFactory.getLog(TestDelegationToken.class);
  
  @Before
  public void setUp() throws Exception {
    config = new HdfsConfiguration();
    config.setLong(DFSConfigKeys.DFS_NAMENODE_DELEGATION_TOKEN_MAX_LIFETIME_KEY, 10000);
    config.setLong(DFSConfigKeys.DFS_NAMENODE_DELEGATION_TOKEN_RENEW_INTERVAL_KEY, 5000);
    config.setBoolean(DFSConfigKeys.DFS_NAMENODE_DELEGATION_TOKEN_ALWAYS_USE_KEY, true);
    config.set("hadoop.security.auth_to_local",
        "RULE:[2:$1@$0](JobTracker@.*FOO.COM)s/@.*//" + "DEFAULT");
    FileSystem.setDefaultUri(config, "hdfs://localhost:" + "0");
    cluster = new MiniDFSCluster.Builder(config).numDataNodes(0).build();
    cluster.waitActive();
    dtSecretManager = NameNodeAdapter.getDtSecretManager(
        cluster.getNamesystem());
  }

  @After
  public void tearDown() throws Exception {
    if(cluster!=null) {
      cluster.shutdown();
    }
  }

  private Token<DelegationTokenIdentifier> generateDelegationToken(
      String owner, String renewer) {
    DelegationTokenIdentifier dtId = new DelegationTokenIdentifier(new Text(
        owner), new Text(renewer), null);
    return new Token<DelegationTokenIdentifier>(dtId, dtSecretManager);
  }
  
  @Test
  public void testDelegationTokenSecretManager() throws Exception {
    Token<DelegationTokenIdentifier> token = generateDelegationToken(
        "SomeUser", "JobTracker");
    // Fake renewer should not be able to renew
    try {
  	  dtSecretManager.renewToken(token, "FakeRenewer");
  	  Assert.fail("should have failed");
    } catch (AccessControlException ace) {
      // PASS
    }
	  dtSecretManager.renewToken(token, "JobTracker");
    DelegationTokenIdentifier identifier = new DelegationTokenIdentifier();
    byte[] tokenId = token.getIdentifier();
    identifier.readFields(new DataInputStream(
             new ByteArrayInputStream(tokenId)));
    Assert.assertTrue(null != dtSecretManager.retrievePassword(identifier));
    LOG.info("Sleep to expire the token");
	  Thread.sleep(6000);
	  //Token should be expired
	  try {
	    dtSecretManager.retrievePassword(identifier);
	    //Should not come here
	    Assert.fail("Token should have expired");
	  } catch (InvalidToken e) {
	    //Success
	  }
	  dtSecretManager.renewToken(token, "JobTracker");
	  LOG.info("Sleep beyond the max lifetime");
	  Thread.sleep(5000);
	  try {
  	  dtSecretManager.renewToken(token, "JobTracker");
  	  Assert.fail("should have been expired");
	  } catch (InvalidToken it) {
	    // PASS
	  }
  }
  
  @Test 
  public void testCancelDelegationToken() throws Exception {
    Token<DelegationTokenIdentifier> token = generateDelegationToken(
        "SomeUser", "JobTracker");
    //Fake renewer should not be able to renew
    try {
      dtSecretManager.cancelToken(token, "FakeCanceller");
      Assert.fail("should have failed");
    } catch (AccessControlException ace) {
      // PASS
    }
    dtSecretManager.cancelToken(token, "JobTracker");
    try {
      dtSecretManager.renewToken(token, "JobTracker");
      Assert.fail("should have failed");
    } catch (InvalidToken it) {
      // PASS
    }
  }
  
  @Test
  public void testAddDelegationTokensDFSApi() throws Exception {
    UserGroupInformation ugi = UserGroupInformation.createRemoteUser("JobTracker");
    DistributedFileSystem dfs = cluster.getFileSystem();
    Credentials creds = new Credentials();
    final Token<?> tokens[] = dfs.addDelegationTokens("JobTracker", creds);
    Assert.assertEquals(1, tokens.length);
    Assert.assertEquals(1, creds.numberOfTokens());
    checkTokenIdentifier(ugi, tokens[0]);

    final Token<?> tokens2[] = dfs.addDelegationTokens("JobTracker", creds);
    Assert.assertEquals(0, tokens2.length); // already have token
    Assert.assertEquals(1, creds.numberOfTokens());
  }
  
  @Test
  public void testDelegationTokenWebHdfsApi() throws Exception {
    ((Log4JLogger)NamenodeWebHdfsMethods.LOG).getLogger().setLevel(Level.ALL);
    final String uri = WebHdfsConstants.WEBHDFS_SCHEME + "://"
        + config.get(DFSConfigKeys.DFS_NAMENODE_HTTP_ADDRESS_KEY);
    //get file system as JobTracker
    final UserGroupInformation ugi = UserGroupInformation.createUserForTesting(
        "JobTracker", new String[]{"user"});
    final WebHdfsFileSystem webhdfs = ugi.doAs(
        new PrivilegedExceptionAction<WebHdfsFileSystem>() {
      @Override
      public WebHdfsFileSystem run() throws Exception {
        return (WebHdfsFileSystem)FileSystem.get(new URI(uri), config);
      }
    });

    { //test addDelegationTokens(..)
      Credentials creds = new Credentials();
      final Token<?> tokens[] = webhdfs.addDelegationTokens("JobTracker", creds);
      Assert.assertEquals(1, tokens.length);
      Assert.assertEquals(1, creds.numberOfTokens());
      Assert.assertSame(tokens[0], creds.getAllTokens().iterator().next());
      checkTokenIdentifier(ugi, tokens[0]);
      final Token<?> tokens2[] = webhdfs.addDelegationTokens("JobTracker", creds);
      Assert.assertEquals(0, tokens2.length);
    }
  }

  @Test
  public void testDelegationTokenWithDoAs() throws Exception {
    final DistributedFileSystem dfs = cluster.getFileSystem();
    final Credentials creds = new Credentials();
    final Token<?> tokens[] = dfs.addDelegationTokens("JobTracker", creds);
    Assert.assertEquals(1, tokens.length);
    @SuppressWarnings("unchecked")
    final Token<DelegationTokenIdentifier> token =
        (Token<DelegationTokenIdentifier>) tokens[0];
    final UserGroupInformation longUgi = UserGroupInformation
        .createRemoteUser("JobTracker/foo.com@FOO.COM");
    final UserGroupInformation shortUgi = UserGroupInformation
        .createRemoteUser("JobTracker");
    longUgi.doAs(new PrivilegedExceptionAction<Object>() {
      @Override
      public Object run() throws IOException {
        try {
          token.renew(config);
        } catch (Exception e) {
          Assert.fail("Could not renew delegation token for user "+longUgi);
        }
        return null;
      }
    });
    shortUgi.doAs(new PrivilegedExceptionAction<Object>() {
      @Override
      public Object run() throws Exception {
        token.renew(config);
        return null;
      }
    });
    longUgi.doAs(new PrivilegedExceptionAction<Object>() {
      @Override
      public Object run() throws IOException {
        try {
          token.cancel(config);
        } catch (Exception e) {
          Assert.fail("Could not cancel delegation token for user "+longUgi);
        }
        return null;
      }
    });
  }
  
  /**
   * Test that the delegation token secret manager only runs when the
   * NN is out of safe mode. This is because the secret manager
   * has to log to the edit log, which should not be written in
   * safe mode. Regression test for HDFS-2579.
   */
  @Test
  public void testDTManagerInSafeMode() throws Exception {
    cluster.startDataNodes(config, 1, true, StartupOption.REGULAR, null);
    FileSystem fs = cluster.getFileSystem();
    for (int i = 0; i < 5; i++) {
      DFSTestUtil.createFile(fs, new Path("/test-" + i), 100, (short)1, 1L);
    }
    cluster.getConfiguration(0).setInt(
        DFSConfigKeys.DFS_NAMENODE_DELEGATION_KEY_UPDATE_INTERVAL_KEY, 500); 
    cluster.getConfiguration(0).setInt(
        DFSConfigKeys.DFS_NAMENODE_SAFEMODE_EXTENSION_KEY, 30000);
    cluster.setWaitSafeMode(false);
    cluster.restartNameNode();
    NameNode nn = cluster.getNameNode();
    assertTrue(nn.isInSafeMode());
    DelegationTokenSecretManager sm =
      NameNodeAdapter.getDtSecretManager(nn.getNamesystem());
    assertFalse("Secret manager should not run in safe mode", sm.isRunning());
    
    NameNodeAdapter.leaveSafeMode(nn);
    assertTrue("Secret manager should start when safe mode is exited",
        sm.isRunning());
    
    LOG.info("========= entering safemode again");
    
    NameNodeAdapter.enterSafeMode(nn, false);
    assertFalse("Secret manager should stop again when safe mode " +
        "is manually entered", sm.isRunning());
    
    // Set the cluster to leave safemode quickly on its own.
    cluster.getConfiguration(0).setInt(
        DFSConfigKeys.DFS_NAMENODE_SAFEMODE_EXTENSION_KEY, 0);
    cluster.setWaitSafeMode(true);
    cluster.restartNameNode();
    nn = cluster.getNameNode();
    sm = NameNodeAdapter.getDtSecretManager(nn.getNamesystem());

    assertFalse(nn.isInSafeMode());
    assertTrue(sm.isRunning());
  }
  
  @SuppressWarnings("unchecked")
  private void checkTokenIdentifier(UserGroupInformation ugi, final Token<?> token)
      throws Exception {
    Assert.assertNotNull(token);
    // should be able to use token.decodeIdentifier() but webhdfs isn't
    // registered with the service loader for token decoding
    DelegationTokenIdentifier identifier = new DelegationTokenIdentifier();
    byte[] tokenId = token.getIdentifier();
    DataInputStream in = new DataInputStream(new ByteArrayInputStream(tokenId));
    try {
      identifier.readFields(in);
    } finally {
      in.close();
    }
    Assert.assertNotNull(identifier);
    LOG.info("A valid token should have non-null password, and should be renewed successfully");
    Assert.assertTrue(null != dtSecretManager.retrievePassword(identifier));
    dtSecretManager.renewToken((Token<DelegationTokenIdentifier>) token, "JobTracker");
    ugi.doAs(
        new PrivilegedExceptionAction<Object>() {
          @Override
          public Object run() throws Exception {
            token.renew(config);
            token.cancel(config);
            return null;
          }
        });
  }
}
