/**
 * 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;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.PrintStream;
import java.io.RandomAccessFile;
import java.io.StringReader;
import java.net.URI;
import java.security.PrivilegedExceptionAction;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;

import com.google.common.collect.Lists;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.crypto.CipherSuite;
import org.apache.hadoop.crypto.CryptoProtocolVersion;
import org.apache.hadoop.crypto.key.JavaKeyStoreProvider;
import org.apache.hadoop.crypto.key.KeyProvider;
import org.apache.hadoop.crypto.key.KeyProviderFactory;
import org.apache.hadoop.fs.CommonConfigurationKeysPublic;
import org.apache.hadoop.fs.CreateFlag;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FSTestWrapper;
import org.apache.hadoop.fs.FileContext;
import org.apache.hadoop.fs.FileContextTestWrapper;
import org.apache.hadoop.fs.FileEncryptionInfo;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.FileSystemTestHelper;
import org.apache.hadoop.fs.FileSystemTestWrapper;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.RemoteIterator;
import org.apache.hadoop.fs.permission.FsPermission;
import org.apache.hadoop.hdfs.client.HdfsAdmin;
import org.apache.hadoop.hdfs.protocol.ClientProtocol;
import org.apache.hadoop.hdfs.protocol.EncryptionZone;
import org.apache.hadoop.hdfs.protocol.HdfsFileStatus;
import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
import org.apache.hadoop.hdfs.protocol.HdfsConstants.SafeModeAction;
import org.apache.hadoop.hdfs.server.namenode.EncryptionFaultInjector;
import org.apache.hadoop.hdfs.server.namenode.EncryptionZoneManager;
import org.apache.hadoop.hdfs.server.namenode.FSImageTestUtil;
import org.apache.hadoop.hdfs.server.namenode.NamenodeFsck;
import org.apache.hadoop.hdfs.tools.DFSck;
import org.apache.hadoop.hdfs.tools.offlineImageViewer.PBImageXmlWriter;
import org.apache.hadoop.hdfs.web.WebHdfsConstants;
import org.apache.hadoop.hdfs.web.WebHdfsTestUtil;
import org.apache.hadoop.io.EnumSetWritable;
import org.apache.hadoop.security.AccessControlException;
import org.apache.hadoop.security.Credentials;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.hadoop.security.token.Token;
import org.apache.hadoop.util.ToolRunner;
import org.apache.hadoop.crypto.key.KeyProviderDelegationTokenExtension.DelegationTokenExtension;
import org.apache.hadoop.crypto.key.KeyProviderCryptoExtension.CryptoExtension;
import org.apache.hadoop.io.Text;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.junit.After;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.mockito.Mockito;

import static org.mockito.Matchers.anyBoolean;
import static org.mockito.Matchers.anyLong;
import static org.mockito.Matchers.anyObject;
import static org.mockito.Matchers.anyShort;
import static org.mockito.Mockito.withSettings;
import static org.mockito.Mockito.any;
import static org.mockito.Mockito.anyString;
import static org.apache.hadoop.hdfs.DFSTestUtil.verifyFilesEqual;
import static org.apache.hadoop.test.GenericTestUtils.assertExceptionContains;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNotEquals;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;

import org.xml.sax.InputSource;
import org.xml.sax.helpers.DefaultHandler;

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

public class TestEncryptionZones {

  private Configuration conf;
  private FileSystemTestHelper fsHelper;

  private MiniDFSCluster cluster;
  protected HdfsAdmin dfsAdmin;
  protected DistributedFileSystem fs;
  private File testRootDir;
  protected final String TEST_KEY = "test_key";

  protected FileSystemTestWrapper fsWrapper;
  protected FileContextTestWrapper fcWrapper;

  protected String getKeyProviderURI() {
    return JavaKeyStoreProvider.SCHEME_NAME + "://file" +
      new Path(testRootDir.toString(), "test.jks").toUri();
  }

  @Before
  public void setup() throws Exception {
    conf = new HdfsConfiguration();
    fsHelper = new FileSystemTestHelper();
    // Set up java key store
    String testRoot = fsHelper.getTestRootDir();
    testRootDir = new File(testRoot).getAbsoluteFile();
    conf.set(DFSConfigKeys.DFS_ENCRYPTION_KEY_PROVIDER_URI, getKeyProviderURI());
    conf.setBoolean(DFSConfigKeys.DFS_NAMENODE_DELEGATION_TOKEN_ALWAYS_USE_KEY, true);
    // Lower the batch size for testing
    conf.setInt(DFSConfigKeys.DFS_NAMENODE_LIST_ENCRYPTION_ZONES_NUM_RESPONSES,
        2);
    cluster = new MiniDFSCluster.Builder(conf).numDataNodes(1).build();
    Logger.getLogger(EncryptionZoneManager.class).setLevel(Level.TRACE);
    fs = cluster.getFileSystem();
    fsWrapper = new FileSystemTestWrapper(fs);
    fcWrapper = new FileContextTestWrapper(
        FileContext.getFileContext(cluster.getURI(), conf));
    dfsAdmin = new HdfsAdmin(cluster.getURI(), conf);
    setProvider();
    // Create a test key
    DFSTestUtil.createKey(TEST_KEY, cluster, conf);
  }
  
  protected void setProvider() {
    // Need to set the client's KeyProvider to the NN's for JKS,
    // else the updates do not get flushed properly
    fs.getClient().setKeyProvider(cluster.getNameNode().getNamesystem()
        .getProvider());
  }

  @After
  public void teardown() {
    if (cluster != null) {
      cluster.shutdown();
    }
    EncryptionFaultInjector.instance = new EncryptionFaultInjector();
  }

  public void assertNumZones(final int numZones) throws IOException {
    RemoteIterator<EncryptionZone> it = dfsAdmin.listEncryptionZones();
    int count = 0;
    while (it.hasNext()) {
      count++;
      it.next();
    }
    assertEquals("Unexpected number of encryption zones!", numZones, count);
  }

  /**
   * Checks that an encryption zone with the specified keyName and path (if not
   * null) is present.
   *
   * @throws IOException if a matching zone could not be found
   */
  public void assertZonePresent(String keyName, String path) throws IOException {
    final RemoteIterator<EncryptionZone> it = dfsAdmin.listEncryptionZones();
    boolean match = false;
    while (it.hasNext()) {
      EncryptionZone zone = it.next();
      boolean matchKey = (keyName == null);
      boolean matchPath = (path == null);
      if (keyName != null && zone.getKeyName().equals(keyName)) {
        matchKey = true;
      }
      if (path != null && zone.getPath().equals(path)) {
        matchPath = true;
      }
      if (matchKey && matchPath) {
        match = true;
        break;
      }
    }
    assertTrue("Did not find expected encryption zone with keyName " + keyName +
            " path " + path, match
    );
  }

  @Test(timeout = 60000)
  public void testBasicOperations() throws Exception {

    int numZones = 0;

    /* Test failure of create EZ on a directory that doesn't exist. */
    final Path zoneParent = new Path("/zones");
    final Path zone1 = new Path(zoneParent, "zone1");
    try {
      dfsAdmin.createEncryptionZone(zone1, TEST_KEY);
      fail("expected /test doesn't exist");
    } catch (IOException e) {
      assertExceptionContains("cannot find", e);
    }

    /* Normal creation of an EZ */
    fsWrapper.mkdir(zone1, FsPermission.getDirDefault(), true);
    dfsAdmin.createEncryptionZone(zone1, TEST_KEY);
    assertNumZones(++numZones);
    assertZonePresent(null, zone1.toString());

    /* Test failure of create EZ on a directory which is already an EZ. */
    try {
      dfsAdmin.createEncryptionZone(zone1, TEST_KEY);
    } catch (IOException e) {
      assertExceptionContains("already in an encryption zone", e);
    }

    /* Test failure of create EZ operation in an existing EZ. */
    final Path zone1Child = new Path(zone1, "child");
    fsWrapper.mkdir(zone1Child, FsPermission.getDirDefault(), false);
    try {
      dfsAdmin.createEncryptionZone(zone1Child, TEST_KEY);
      fail("EZ in an EZ");
    } catch (IOException e) {
      assertExceptionContains("already in an encryption zone", e);
    }

    /* create EZ on parent of an EZ should fail */
    try {
      dfsAdmin.createEncryptionZone(zoneParent, TEST_KEY);
      fail("EZ over an EZ");
    } catch (IOException e) {
      assertExceptionContains("encryption zone for a non-empty directory", e);
    }

    /* create EZ on a folder with a folder fails */
    final Path notEmpty = new Path("/notEmpty");
    final Path notEmptyChild = new Path(notEmpty, "child");
    fsWrapper.mkdir(notEmptyChild, FsPermission.getDirDefault(), true);
    try {
      dfsAdmin.createEncryptionZone(notEmpty, TEST_KEY);
      fail("Created EZ on an non-empty directory with folder");
    } catch (IOException e) {
      assertExceptionContains("create an encryption zone", e);
    }
    fsWrapper.delete(notEmptyChild, false);

    /* create EZ on a folder with a file fails */
    fsWrapper.createFile(notEmptyChild);
    try {
      dfsAdmin.createEncryptionZone(notEmpty, TEST_KEY);
      fail("Created EZ on an non-empty directory with file");
    } catch (IOException e) {
      assertExceptionContains("create an encryption zone", e);
    }

    /* Test failure of create EZ on a file. */
    try {
      dfsAdmin.createEncryptionZone(notEmptyChild, TEST_KEY);
      fail("Created EZ on a file");
    } catch (IOException e) {
      assertExceptionContains("create an encryption zone for a file.", e);
    }

    /* Test failure of creating an EZ passing a key that doesn't exist. */
    final Path zone2 = new Path("/zone2");
    fsWrapper.mkdir(zone2, FsPermission.getDirDefault(), false);
    final String myKeyName = "mykeyname";
    try {
      dfsAdmin.createEncryptionZone(zone2, myKeyName);
      fail("expected key doesn't exist");
    } catch (IOException e) {
      assertExceptionContains("doesn't exist.", e);
    }

    /* Test failure of empty and null key name */
    try {
      dfsAdmin.createEncryptionZone(zone2, "");
      fail("created a zone with empty key name");
    } catch (IOException e) {
      assertExceptionContains("Must specify a key name when creating", e);
    }
    try {
      dfsAdmin.createEncryptionZone(zone2, null);
      fail("created a zone with null key name");
    } catch (IOException e) {
      assertExceptionContains("Must specify a key name when creating", e);
    }

    assertNumZones(1);

    /* Test success of creating an EZ when they key exists. */
    DFSTestUtil.createKey(myKeyName, cluster, conf);
    dfsAdmin.createEncryptionZone(zone2, myKeyName);
    assertNumZones(++numZones);
    assertZonePresent(myKeyName, zone2.toString());

    /* Test failure of create encryption zones as a non super user. */
    final UserGroupInformation user = UserGroupInformation.
        createUserForTesting("user", new String[] { "mygroup" });
    final Path nonSuper = new Path("/nonSuper");
    fsWrapper.mkdir(nonSuper, FsPermission.getDirDefault(), false);

    user.doAs(new PrivilegedExceptionAction<Object>() {
      @Override
      public Object run() throws Exception {
        final HdfsAdmin userAdmin =
            new HdfsAdmin(FileSystem.getDefaultUri(conf), conf);
        try {
          userAdmin.createEncryptionZone(nonSuper, TEST_KEY);
          fail("createEncryptionZone is superuser-only operation");
        } catch (AccessControlException e) {
          assertExceptionContains("Superuser privilege is required", e);
        }
        return null;
      }
    });

    // Test success of creating an encryption zone a few levels down.
    Path deepZone = new Path("/d/e/e/p/zone");
    fsWrapper.mkdir(deepZone, FsPermission.getDirDefault(), true);
    dfsAdmin.createEncryptionZone(deepZone, TEST_KEY);
    assertNumZones(++numZones);
    assertZonePresent(null, deepZone.toString());

    // Create and list some zones to test batching of listEZ
    for (int i=1; i<6; i++) {
      final Path zonePath = new Path("/listZone" + i);
      fsWrapper.mkdir(zonePath, FsPermission.getDirDefault(), false);
      dfsAdmin.createEncryptionZone(zonePath, TEST_KEY);
      numZones++;
      assertNumZones(numZones);
      assertZonePresent(null, zonePath.toString());
    }

    fs.setSafeMode(SafeModeAction.SAFEMODE_ENTER);
    fs.saveNamespace();
    fs.setSafeMode(SafeModeAction.SAFEMODE_LEAVE);
    cluster.restartNameNode(true);
    assertNumZones(numZones);
    assertZonePresent(null, zone1.toString());

    // Verify newly added ez is present after restarting the NameNode
    // without persisting the namespace.
    Path nonpersistZone = new Path("/nonpersistZone");
    fsWrapper.mkdir(nonpersistZone, FsPermission.getDirDefault(), false);
    dfsAdmin.createEncryptionZone(nonpersistZone, TEST_KEY);
    numZones++;
    cluster.restartNameNode(true);
    assertNumZones(numZones);
    assertZonePresent(null, nonpersistZone.toString());
  }

  /**
   * Test listing encryption zones as a non super user.
   */
  @Test(timeout = 60000)
  public void testListEncryptionZonesAsNonSuperUser() throws Exception {

    final UserGroupInformation user = UserGroupInformation.
        createUserForTesting("user", new String[] { "mygroup" });

    final Path testRoot = new Path("/tmp/TestEncryptionZones");
    final Path superPath = new Path(testRoot, "superuseronly");
    final Path allPath = new Path(testRoot, "accessall");

    fsWrapper.mkdir(superPath, new FsPermission((short) 0700), true);
    dfsAdmin.createEncryptionZone(superPath, TEST_KEY);

    fsWrapper.mkdir(allPath, new FsPermission((short) 0707), true);
    dfsAdmin.createEncryptionZone(allPath, TEST_KEY);

    user.doAs(new PrivilegedExceptionAction<Object>() {
      @Override
      public Object run() throws Exception {
        final HdfsAdmin userAdmin =
            new HdfsAdmin(FileSystem.getDefaultUri(conf), conf);
        try {
          userAdmin.listEncryptionZones();
        } catch (AccessControlException e) {
          assertExceptionContains("Superuser privilege is required", e);
        }
        return null;
      }
    });
  }

  /**
   * Test getEncryptionZoneForPath as a non super user.
   */
  @Test(timeout = 60000)
  public void testGetEZAsNonSuperUser() throws Exception {

    final UserGroupInformation user = UserGroupInformation.
            createUserForTesting("user", new String[] { "mygroup" });

    final Path testRoot = new Path("/tmp/TestEncryptionZones");
    final Path superPath = new Path(testRoot, "superuseronly");
    final Path superPathFile = new Path(superPath, "file1");
    final Path allPath = new Path(testRoot, "accessall");
    final Path allPathFile = new Path(allPath, "file1");
    final Path nonEZDir = new Path(testRoot, "nonEZDir");
    final Path nonEZFile = new Path(nonEZDir, "file1");
    final Path nonexistent = new Path("/nonexistent");
    final int len = 8192;

    fsWrapper.mkdir(testRoot, new FsPermission((short) 0777), true);
    fsWrapper.mkdir(superPath, new FsPermission((short) 0700), false);
    fsWrapper.mkdir(allPath, new FsPermission((short) 0777), false);
    fsWrapper.mkdir(nonEZDir, new FsPermission((short) 0777), false);
    dfsAdmin.createEncryptionZone(superPath, TEST_KEY);
    dfsAdmin.createEncryptionZone(allPath, TEST_KEY);
    dfsAdmin.allowSnapshot(new Path("/"));
    final Path newSnap = fs.createSnapshot(new Path("/"));
    DFSTestUtil.createFile(fs, superPathFile, len, (short) 1, 0xFEED);
    DFSTestUtil.createFile(fs, allPathFile, len, (short) 1, 0xFEED);
    DFSTestUtil.createFile(fs, nonEZFile, len, (short) 1, 0xFEED);

    user.doAs(new PrivilegedExceptionAction<Object>() {
      @Override
      public Object run() throws Exception {
        final HdfsAdmin userAdmin =
            new HdfsAdmin(FileSystem.getDefaultUri(conf), conf);

        // Check null arg
        try {
          userAdmin.getEncryptionZoneForPath(null);
          fail("should have thrown NPE");
        } catch (NullPointerException e) {
          /*
           * IWBNI we could use assertExceptionContains, but the NPE that is
           * thrown has no message text.
           */
        }

        // Check operation with accessible paths
        assertEquals("expected ez path", allPath.toString(),
            userAdmin.getEncryptionZoneForPath(allPath).getPath().
            toString());
        assertEquals("expected ez path", allPath.toString(),
            userAdmin.getEncryptionZoneForPath(allPathFile).getPath().
            toString());

        // Check operation with inaccessible (lack of permissions) path
        try {
          userAdmin.getEncryptionZoneForPath(superPathFile);
          fail("expected AccessControlException");
        } catch (AccessControlException e) {
          assertExceptionContains("Permission denied:", e);
        }

        assertNull("expected null for nonexistent path",
            userAdmin.getEncryptionZoneForPath(nonexistent));

        // Check operation with non-ez paths
        assertNull("expected null for non-ez path",
            userAdmin.getEncryptionZoneForPath(nonEZDir));
        assertNull("expected null for non-ez path",
            userAdmin.getEncryptionZoneForPath(nonEZFile));

        // Check operation with snapshots
        String snapshottedAllPath = newSnap.toString() + allPath.toString();
        assertEquals("expected ez path", allPath.toString(),
            userAdmin.getEncryptionZoneForPath(
                new Path(snapshottedAllPath)).getPath().toString());

        /*
         * Delete the file from the non-snapshot and test that it is still ok
         * in the ez.
         */
        fs.delete(allPathFile, false);
        assertEquals("expected ez path", allPath.toString(),
            userAdmin.getEncryptionZoneForPath(
                new Path(snapshottedAllPath)).getPath().toString());

        // Delete the ez and make sure ss's ez is still ok.
        fs.delete(allPath, true);
        assertEquals("expected ez path", allPath.toString(),
            userAdmin.getEncryptionZoneForPath(
                new Path(snapshottedAllPath)).getPath().toString());
        assertNull("expected null for deleted file path",
            userAdmin.getEncryptionZoneForPath(allPathFile));
        assertNull("expected null for deleted directory path",
            userAdmin.getEncryptionZoneForPath(allPath));
        return null;
      }
    });
  }

  /**
   * Test success of Rename EZ on a directory which is already an EZ.
   */
  private void doRenameEncryptionZone(FSTestWrapper wrapper) throws Exception {
    final Path testRoot = new Path("/tmp/TestEncryptionZones");
    final Path pathFoo = new Path(testRoot, "foo");
    final Path pathFooBaz = new Path(pathFoo, "baz");
    final Path pathFooBazFile = new Path(pathFooBaz, "file");
    final Path pathFooBar = new Path(pathFoo, "bar");
    final Path pathFooBarFile = new Path(pathFooBar, "file");
    final int len = 8192;
    wrapper.mkdir(pathFoo, FsPermission.getDirDefault(), true);
    dfsAdmin.createEncryptionZone(pathFoo, TEST_KEY);
    wrapper.mkdir(pathFooBaz, FsPermission.getDirDefault(), true);
    DFSTestUtil.createFile(fs, pathFooBazFile, len, (short) 1, 0xFEED);
    String contents = DFSTestUtil.readFile(fs, pathFooBazFile);
    try {
      wrapper.rename(pathFooBaz, testRoot);
    } catch (IOException e) {
      assertExceptionContains(pathFooBaz.toString() + " can't be moved from" +
              " an encryption zone.", e
      );
    }

    // Verify that we can rename dir and files within an encryption zone.
    assertTrue(fs.rename(pathFooBaz, pathFooBar));
    assertTrue("Rename of dir and file within ez failed",
        !wrapper.exists(pathFooBaz) && wrapper.exists(pathFooBar));
    assertEquals("Renamed file contents not the same",
        contents, DFSTestUtil.readFile(fs, pathFooBarFile));

    // Verify that we can rename an EZ root
    final Path newFoo = new Path(testRoot, "newfoo");
    assertTrue("Rename of EZ root", fs.rename(pathFoo, newFoo));
    assertTrue("Rename of EZ root failed",
        !wrapper.exists(pathFoo) && wrapper.exists(newFoo));

    // Verify that we can't rename an EZ root onto itself
    try {
      wrapper.rename(newFoo, newFoo);
    } catch (IOException e) {
      assertExceptionContains("are the same", e);
    }
  }

  @Test(timeout = 60000)
  public void testRenameFileSystem() throws Exception {
    doRenameEncryptionZone(fsWrapper);
  }

  @Test(timeout = 60000)
  public void testRenameFileContext() throws Exception {
    doRenameEncryptionZone(fcWrapper);
  }

  private FileEncryptionInfo getFileEncryptionInfo(Path path) throws Exception {
    LocatedBlocks blocks = fs.getClient().getLocatedBlocks(path.toString(), 0);
    return blocks.getFileEncryptionInfo();
  }

  @Test(timeout = 120000)
  public void testReadWrite() throws Exception {
    final HdfsAdmin dfsAdmin =
        new HdfsAdmin(FileSystem.getDefaultUri(conf), conf);
    // Create a base file for comparison
    final Path baseFile = new Path("/base");
    final int len = 8192;
    DFSTestUtil.createFile(fs, baseFile, len, (short) 1, 0xFEED);
    // Create the first enc file
    final Path zone = new Path("/zone");
    fs.mkdirs(zone);
    dfsAdmin.createEncryptionZone(zone, TEST_KEY);
    final Path encFile1 = new Path(zone, "myfile");
    DFSTestUtil.createFile(fs, encFile1, len, (short) 1, 0xFEED);
    // Read them back in and compare byte-by-byte
    verifyFilesEqual(fs, baseFile, encFile1, len);
    // Roll the key of the encryption zone
    assertNumZones(1);
    String keyName = dfsAdmin.listEncryptionZones().next().getKeyName();
    cluster.getNamesystem().getProvider().rollNewVersion(keyName);
    // Read them back in and compare byte-by-byte
    verifyFilesEqual(fs, baseFile, encFile1, len);
    // Write a new enc file and validate
    final Path encFile2 = new Path(zone, "myfile2");
    DFSTestUtil.createFile(fs, encFile2, len, (short) 1, 0xFEED);
    // FEInfos should be different
    FileEncryptionInfo feInfo1 = getFileEncryptionInfo(encFile1);
    FileEncryptionInfo feInfo2 = getFileEncryptionInfo(encFile2);
    assertFalse("EDEKs should be different", Arrays
        .equals(feInfo1.getEncryptedDataEncryptionKey(),
            feInfo2.getEncryptedDataEncryptionKey()));
    assertNotEquals("Key was rolled, versions should be different",
        feInfo1.getEzKeyVersionName(), feInfo2.getEzKeyVersionName());
    // Contents still equal
    verifyFilesEqual(fs, encFile1, encFile2, len);
  }

  @Test(timeout = 120000)
  public void testReadWriteUsingWebHdfs() throws Exception {
    final HdfsAdmin dfsAdmin =
        new HdfsAdmin(FileSystem.getDefaultUri(conf), conf);
    final FileSystem webHdfsFs = WebHdfsTestUtil.getWebHdfsFileSystem(conf,
        WebHdfsConstants.WEBHDFS_SCHEME);

    final Path zone = new Path("/zone");
    fs.mkdirs(zone);
    dfsAdmin.createEncryptionZone(zone, TEST_KEY);

    /* Create an unencrypted file for comparison purposes. */
    final Path unencFile = new Path("/unenc");
    final int len = 8192;
    DFSTestUtil.createFile(webHdfsFs, unencFile, len, (short) 1, 0xFEED);

    /*
     * Create the same file via webhdfs, but this time encrypted. Compare it
     * using both webhdfs and DFS.
     */
    final Path encFile1 = new Path(zone, "myfile");
    DFSTestUtil.createFile(webHdfsFs, encFile1, len, (short) 1, 0xFEED);
    verifyFilesEqual(webHdfsFs, unencFile, encFile1, len);
    verifyFilesEqual(fs, unencFile, encFile1, len);

    /*
     * Same thing except this time create the encrypted file using DFS.
     */
    final Path encFile2 = new Path(zone, "myfile2");
    DFSTestUtil.createFile(fs, encFile2, len, (short) 1, 0xFEED);
    verifyFilesEqual(webHdfsFs, unencFile, encFile2, len);
    verifyFilesEqual(fs, unencFile, encFile2, len);

    /* Verify appending to files works correctly. */
    appendOneByte(fs, unencFile);
    appendOneByte(webHdfsFs, encFile1);
    appendOneByte(fs, encFile2);
    verifyFilesEqual(webHdfsFs, unencFile, encFile1, len);
    verifyFilesEqual(fs, unencFile, encFile1, len);
    verifyFilesEqual(webHdfsFs, unencFile, encFile2, len);
    verifyFilesEqual(fs, unencFile, encFile2, len);
  }

  private void appendOneByte(FileSystem fs, Path p) throws IOException {
    final FSDataOutputStream out = fs.append(p);
    out.write((byte) 0x123);
    out.close();
  }

  @Test(timeout = 60000)
  public void testVersionAndSuiteNegotiation() throws Exception {
    final HdfsAdmin dfsAdmin =
        new HdfsAdmin(FileSystem.getDefaultUri(conf), conf);
    final Path zone = new Path("/zone");
    fs.mkdirs(zone);
    dfsAdmin.createEncryptionZone(zone, TEST_KEY);
    // Create a file in an EZ, which should succeed
    DFSTestUtil
        .createFile(fs, new Path(zone, "success1"), 0, (short) 1, 0xFEED);
    // Pass no supported versions, fail
    DFSOutputStream.SUPPORTED_CRYPTO_VERSIONS = new CryptoProtocolVersion[] {};
    try {
      DFSTestUtil.createFile(fs, new Path(zone, "fail"), 0, (short) 1, 0xFEED);
      fail("Created a file without specifying a crypto protocol version");
    } catch (UnknownCryptoProtocolVersionException e) {
      assertExceptionContains("No crypto protocol versions", e);
    }
    // Pass some unknown versions, fail
    DFSOutputStream.SUPPORTED_CRYPTO_VERSIONS = new CryptoProtocolVersion[]
        { CryptoProtocolVersion.UNKNOWN, CryptoProtocolVersion.UNKNOWN };
    try {
      DFSTestUtil.createFile(fs, new Path(zone, "fail"), 0, (short) 1, 0xFEED);
      fail("Created a file without specifying a known crypto protocol version");
    } catch (UnknownCryptoProtocolVersionException e) {
      assertExceptionContains("No crypto protocol versions", e);
    }
    // Pass some unknown and a good cipherSuites, success
    DFSOutputStream.SUPPORTED_CRYPTO_VERSIONS =
        new CryptoProtocolVersion[] {
            CryptoProtocolVersion.UNKNOWN,
            CryptoProtocolVersion.UNKNOWN,
            CryptoProtocolVersion.ENCRYPTION_ZONES };
    DFSTestUtil
        .createFile(fs, new Path(zone, "success2"), 0, (short) 1, 0xFEED);
    DFSOutputStream.SUPPORTED_CRYPTO_VERSIONS =
        new CryptoProtocolVersion[] {
            CryptoProtocolVersion.ENCRYPTION_ZONES,
            CryptoProtocolVersion.UNKNOWN,
            CryptoProtocolVersion.UNKNOWN} ;
    DFSTestUtil
        .createFile(fs, new Path(zone, "success3"), 4096, (short) 1, 0xFEED);
    // Check KeyProvider state
    // Flushing the KP on the NN, since it caches, and init a test one
    cluster.getNamesystem().getProvider().flush();
    KeyProvider provider = KeyProviderFactory
        .get(new URI(conf.get(DFSConfigKeys.DFS_ENCRYPTION_KEY_PROVIDER_URI)),
            conf);
    List<String> keys = provider.getKeys();
    assertEquals("Expected NN to have created one key per zone", 1,
        keys.size());
    List<KeyProvider.KeyVersion> allVersions = Lists.newArrayList();
    for (String key : keys) {
      List<KeyProvider.KeyVersion> versions = provider.getKeyVersions(key);
      assertEquals("Should only have one key version per key", 1,
          versions.size());
      allVersions.addAll(versions);
    }
    // Check that the specified CipherSuite was correctly saved on the NN
    for (int i = 2; i <= 3; i++) {
      FileEncryptionInfo feInfo =
          getFileEncryptionInfo(new Path(zone.toString() +
              "/success" + i));
      assertEquals(feInfo.getCipherSuite(), CipherSuite.AES_CTR_NOPADDING);
    }

    DFSClient old = fs.dfs;
    try {
      testCipherSuiteNegotiation(fs, conf);
    } finally {
      fs.dfs = old;
    }
  }

  @SuppressWarnings("unchecked")
  private static void mockCreate(ClientProtocol mcp,
      CipherSuite suite, CryptoProtocolVersion version) throws Exception {
    Mockito.doReturn(
        new HdfsFileStatus(0, false, 1, 1024, 0, 0, new FsPermission(
            (short) 777), "owner", "group", new byte[0], new byte[0],
            1010, 0, new FileEncryptionInfo(suite,
            version, new byte[suite.getAlgorithmBlockSize()],
            new byte[suite.getAlgorithmBlockSize()],
            "fakeKey", "fakeVersion"),
            (byte) 0))
        .when(mcp)
        .create(anyString(), (FsPermission) anyObject(), anyString(),
            (EnumSetWritable<CreateFlag>) anyObject(), anyBoolean(),
            anyShort(), anyLong(), (CryptoProtocolVersion[]) anyObject());
  }

  // This test only uses mocks. Called from the end of an existing test to
  // avoid an extra mini cluster.
  private static void testCipherSuiteNegotiation(DistributedFileSystem fs,
      Configuration conf) throws Exception {
    // Set up mock ClientProtocol to test client-side CipherSuite negotiation
    final ClientProtocol mcp = Mockito.mock(ClientProtocol.class);

    // Try with an empty conf
    final Configuration noCodecConf = new Configuration(conf);
    final CipherSuite suite = CipherSuite.AES_CTR_NOPADDING;
    final String confKey = CommonConfigurationKeysPublic
        .HADOOP_SECURITY_CRYPTO_CODEC_CLASSES_KEY_PREFIX + suite
        .getConfigSuffix();
    noCodecConf.set(confKey, "");
    fs.dfs = new DFSClient(null, mcp, noCodecConf, null);
    mockCreate(mcp, suite, CryptoProtocolVersion.ENCRYPTION_ZONES);
    try {
      fs.create(new Path("/mock"));
      fail("Created with no configured codecs!");
    } catch (UnknownCipherSuiteException e) {
      assertExceptionContains("No configuration found for the cipher", e);
    }

    // Try create with an UNKNOWN CipherSuite
    fs.dfs = new DFSClient(null, mcp, conf, null);
    CipherSuite unknown = CipherSuite.UNKNOWN;
    unknown.setUnknownValue(989);
    mockCreate(mcp, unknown, CryptoProtocolVersion.ENCRYPTION_ZONES);
    try {
      fs.create(new Path("/mock"));
      fail("Created with unknown cipher!");
    } catch (IOException e) {
      assertExceptionContains("unknown CipherSuite with ID 989", e);
    }
  }

  @Test(timeout = 120000)
  public void testCreateEZWithNoProvider() throws Exception {
    // Unset the key provider and make sure EZ ops don't work
    final Configuration clusterConf = cluster.getConfiguration(0);
    clusterConf.unset(DFSConfigKeys.DFS_ENCRYPTION_KEY_PROVIDER_URI);
    cluster.restartNameNode(true);
    cluster.waitActive();
    final Path zone1 = new Path("/zone1");
    fsWrapper.mkdir(zone1, FsPermission.getDirDefault(), true);
    try {
      dfsAdmin.createEncryptionZone(zone1, TEST_KEY);
      fail("expected exception");
    } catch (IOException e) {
      assertExceptionContains("since no key provider is available", e);
    }
    final Path jksPath = new Path(testRootDir.toString(), "test.jks");
    clusterConf.set(DFSConfigKeys.DFS_ENCRYPTION_KEY_PROVIDER_URI,
        JavaKeyStoreProvider.SCHEME_NAME + "://file" + jksPath.toUri()
    );
    // Try listing EZs as well
    assertNumZones(0);
  }

  @Test(timeout = 120000)
  public void testIsEncryptedMethod() throws Exception {
    doTestIsEncryptedMethod(new Path("/"));
    doTestIsEncryptedMethod(new Path("/.reserved/raw"));
  }

  private void doTestIsEncryptedMethod(Path prefix) throws Exception {
    try {
      dTIEM(prefix);
    } finally {
      for (FileStatus s : fsWrapper.listStatus(prefix)) {
        fsWrapper.delete(s.getPath(), true);
      }
    }
  }

  private void dTIEM(Path prefix) throws Exception {
    final HdfsAdmin dfsAdmin =
      new HdfsAdmin(FileSystem.getDefaultUri(conf), conf);
    // Create an unencrypted file to check isEncrypted returns false
    final Path baseFile = new Path(prefix, "base");
    fsWrapper.createFile(baseFile);
    FileStatus stat = fsWrapper.getFileStatus(baseFile);
    assertFalse("Expected isEncrypted to return false for " + baseFile,
        stat.isEncrypted());

    // Create an encrypted file to check isEncrypted returns true
    final Path zone = new Path(prefix, "zone");
    fsWrapper.mkdir(zone, FsPermission.getDirDefault(), true);
    dfsAdmin.createEncryptionZone(zone, TEST_KEY);
    final Path encFile = new Path(zone, "encfile");
    fsWrapper.createFile(encFile);
    stat = fsWrapper.getFileStatus(encFile);
    assertTrue("Expected isEncrypted to return true for enc file" + encFile,
        stat.isEncrypted());

    // check that it returns true for an ez root
    stat = fsWrapper.getFileStatus(zone);
    assertTrue("Expected isEncrypted to return true for ezroot",
        stat.isEncrypted());

    // check that it returns true for a dir in the ez
    final Path zoneSubdir = new Path(zone, "subdir");
    fsWrapper.mkdir(zoneSubdir, FsPermission.getDirDefault(), true);
    stat = fsWrapper.getFileStatus(zoneSubdir);
    assertTrue(
        "Expected isEncrypted to return true for ez subdir " + zoneSubdir,
        stat.isEncrypted());

    // check that it returns false for a non ez dir
    final Path nonEzDirPath = new Path(prefix, "nonzone");
    fsWrapper.mkdir(nonEzDirPath, FsPermission.getDirDefault(), true);
    stat = fsWrapper.getFileStatus(nonEzDirPath);
    assertFalse(
        "Expected isEncrypted to return false for directory " + nonEzDirPath,
        stat.isEncrypted());

    // check that it returns true for listings within an ez
    FileStatus[] statuses = fsWrapper.listStatus(zone);
    for (FileStatus s : statuses) {
      assertTrue("Expected isEncrypted to return true for ez stat " + zone,
          s.isEncrypted());
    }

    statuses = fsWrapper.listStatus(encFile);
    for (FileStatus s : statuses) {
      assertTrue(
          "Expected isEncrypted to return true for ez file stat " + encFile,
          s.isEncrypted());
    }

    // check that it returns false for listings outside an ez
    statuses = fsWrapper.listStatus(nonEzDirPath);
    for (FileStatus s : statuses) {
      assertFalse(
          "Expected isEncrypted to return false for nonez stat " + nonEzDirPath,
          s.isEncrypted());
    }

    statuses = fsWrapper.listStatus(baseFile);
    for (FileStatus s : statuses) {
      assertFalse(
          "Expected isEncrypted to return false for non ez stat " + baseFile,
          s.isEncrypted());
    }
  }

  private class MyInjector extends EncryptionFaultInjector {
    int generateCount;
    CountDownLatch ready;
    CountDownLatch wait;

    public MyInjector() {
      this.ready = new CountDownLatch(1);
      this.wait = new CountDownLatch(1);
    }

    @Override
    public void startFileAfterGenerateKey() throws IOException {
      ready.countDown();
      try {
        wait.await();
      } catch (InterruptedException e) {
        throw new IOException(e);
      }
      generateCount++;
    }
  }

  private class CreateFileTask implements Callable<Void> {
    private FileSystemTestWrapper fsWrapper;
    private Path name;

    CreateFileTask(FileSystemTestWrapper fsWrapper, Path name) {
      this.fsWrapper = fsWrapper;
      this.name = name;
    }

    @Override
    public Void call() throws Exception {
      fsWrapper.createFile(name);
      return null;
    }
  }

  private class InjectFaultTask implements Callable<Void> {
    final Path zone1 = new Path("/zone1");
    final Path file = new Path(zone1, "file1");
    final ExecutorService executor = Executors.newSingleThreadExecutor();

    MyInjector injector;

    @Override
    public Void call() throws Exception {
      // Set up the injector
      injector = new MyInjector();
      EncryptionFaultInjector.instance = injector;
      Future<Void> future =
          executor.submit(new CreateFileTask(fsWrapper, file));
      injector.ready.await();
      // Do the fault
      doFault();
      // Allow create to proceed
      injector.wait.countDown();
      future.get();
      // Cleanup and postconditions
      doCleanup();
      return null;
    }

    public void doFault() throws Exception {}

    public void doCleanup() throws Exception {}
  }

  /**
   * Tests the retry logic in startFile. We release the lock while generating
   * an EDEK, so tricky things can happen in the intervening time.
   */
  @Test(timeout = 120000)
  public void testStartFileRetry() throws Exception {
    final Path zone1 = new Path("/zone1");
    final Path file = new Path(zone1, "file1");
    fsWrapper.mkdir(zone1, FsPermission.getDirDefault(), true);
    ExecutorService executor = Executors.newSingleThreadExecutor();

    // Test when the parent directory becomes an EZ
    executor.submit(new InjectFaultTask() {
      @Override
      public void doFault() throws Exception {
        dfsAdmin.createEncryptionZone(zone1, TEST_KEY);
      }
      @Override
      public void doCleanup() throws Exception {
        assertEquals("Expected a startFile retry", 2, injector.generateCount);
        fsWrapper.delete(file, false);
      }
    }).get();

    // Test when the parent directory unbecomes an EZ
    executor.submit(new InjectFaultTask() {
      @Override
      public void doFault() throws Exception {
        fsWrapper.delete(zone1, true);
      }
      @Override
      public void doCleanup() throws Exception {
        assertEquals("Expected no startFile retries", 1, injector.generateCount);
        fsWrapper.delete(file, false);
      }
    }).get();

    // Test when the parent directory becomes a different EZ
    fsWrapper.mkdir(zone1, FsPermission.getDirDefault(), true);
    final String otherKey = "other_key";
    DFSTestUtil.createKey(otherKey, cluster, conf);
    dfsAdmin.createEncryptionZone(zone1, TEST_KEY);

    executor.submit(new InjectFaultTask() {
      @Override
      public void doFault() throws Exception {
        fsWrapper.delete(zone1, true);
        fsWrapper.mkdir(zone1, FsPermission.getDirDefault(), true);
        dfsAdmin.createEncryptionZone(zone1, otherKey);
      }
      @Override
      public void doCleanup() throws Exception {
        assertEquals("Expected a startFile retry", 2, injector.generateCount);
        fsWrapper.delete(zone1, true);
      }
    }).get();

    // Test that the retry limit leads to an error
    fsWrapper.mkdir(zone1, FsPermission.getDirDefault(), true);
    final String anotherKey = "another_key";
    DFSTestUtil.createKey(anotherKey, cluster, conf);
    dfsAdmin.createEncryptionZone(zone1, anotherKey);
    String keyToUse = otherKey;

    MyInjector injector = new MyInjector();
    EncryptionFaultInjector.instance = injector;
    Future<?> future = executor.submit(new CreateFileTask(fsWrapper, file));

    // Flip-flop between two EZs to repeatedly fail
    for (int i=0; i<DFSOutputStream.CREATE_RETRY_COUNT+1; i++) {
      injector.ready.await();
      fsWrapper.delete(zone1, true);
      fsWrapper.mkdir(zone1, FsPermission.getDirDefault(), true);
      dfsAdmin.createEncryptionZone(zone1, keyToUse);
      if (keyToUse == otherKey) {
        keyToUse = anotherKey;
      } else {
        keyToUse = otherKey;
      }
      injector.wait.countDown();
      injector = new MyInjector();
      EncryptionFaultInjector.instance = injector;
    }
    try {
      future.get();
      fail("Expected exception from too many retries");
    } catch (ExecutionException e) {
      assertExceptionContains(
          "Too many retries because of encryption zone operations",
          e.getCause());
    }
  }

  /**
   * Tests obtaining delegation token from stored key
   */
  @Test(timeout = 120000)
  public void testDelegationToken() throws Exception {
    UserGroupInformation.createRemoteUser("JobTracker");
    DistributedFileSystem dfs = cluster.getFileSystem();
    KeyProvider keyProvider = Mockito.mock(KeyProvider.class,
        withSettings().extraInterfaces(
            DelegationTokenExtension.class,
            CryptoExtension.class));
    Mockito.when(keyProvider.getConf()).thenReturn(conf);
    byte[] testIdentifier = "Test identifier for delegation token".getBytes();

    Token<?> testToken = new Token(testIdentifier, new byte[0],
        new Text(), new Text());
    Mockito.when(((DelegationTokenExtension)keyProvider).
        addDelegationTokens(anyString(), (Credentials)any())).
        thenReturn(new Token<?>[] { testToken });

    dfs.getClient().setKeyProvider(keyProvider);

    Credentials creds = new Credentials();
    final Token<?> tokens[] = dfs.addDelegationTokens("JobTracker", creds);
    DistributedFileSystem.LOG.debug("Delegation tokens: " +
        Arrays.asList(tokens));
    Assert.assertEquals(2, tokens.length);
    Assert.assertEquals(tokens[1], testToken);
    Assert.assertEquals(1, creds.numberOfTokens());
  }

  /**
   * Test running fsck on a system with encryption zones.
   */
  @Test(timeout = 60000)
  public void testFsckOnEncryptionZones() throws Exception {
    final int len = 8196;
    final Path zoneParent = new Path("/zones");
    final Path zone1 = new Path(zoneParent, "zone1");
    final Path zone1File = new Path(zone1, "file");
    fsWrapper.mkdir(zone1, FsPermission.getDirDefault(), true);
    dfsAdmin.createEncryptionZone(zone1, TEST_KEY);
    DFSTestUtil.createFile(fs, zone1File, len, (short) 1, 0xFEED);
    ByteArrayOutputStream bStream = new ByteArrayOutputStream();
    PrintStream out = new PrintStream(bStream, true);
    int errCode = ToolRunner.run(new DFSck(conf, out),
        new String[]{ "/" });
    assertEquals("Fsck ran with non-zero error code", 0, errCode);
    String result = bStream.toString();
    assertTrue("Fsck did not return HEALTHY status",
        result.contains(NamenodeFsck.HEALTHY_STATUS));

    // Run fsck directly on the encryption zone instead of root
    errCode = ToolRunner.run(new DFSck(conf, out),
        new String[]{ zoneParent.toString() });
    assertEquals("Fsck ran with non-zero error code", 0, errCode);
    result = bStream.toString();
    assertTrue("Fsck did not return HEALTHY status",
        result.contains(NamenodeFsck.HEALTHY_STATUS));
  }

  /**
   * Test correctness of successive snapshot creation and deletion
   * on a system with encryption zones.
   */
  @Test(timeout = 60000)
  public void testSnapshotsOnEncryptionZones() throws Exception {
    final String TEST_KEY2 = "testkey2";
    DFSTestUtil.createKey(TEST_KEY2, cluster, conf);

    final int len = 8196;
    final Path zoneParent = new Path("/zones");
    final Path zone = new Path(zoneParent, "zone");
    final Path zoneFile = new Path(zone, "zoneFile");
    fsWrapper.mkdir(zone, FsPermission.getDirDefault(), true);
    dfsAdmin.allowSnapshot(zoneParent);
    dfsAdmin.createEncryptionZone(zone, TEST_KEY);
    DFSTestUtil.createFile(fs, zoneFile, len, (short) 1, 0xFEED);
    String contents = DFSTestUtil.readFile(fs, zoneFile);
    final Path snap1 = fs.createSnapshot(zoneParent, "snap1");
    final Path snap1Zone = new Path(snap1, zone.getName());
    assertEquals("Got unexpected ez path", zone.toString(),
        dfsAdmin.getEncryptionZoneForPath(snap1Zone).getPath().toString());

    // Now delete the encryption zone, recreate the dir, and take another
    // snapshot
    fsWrapper.delete(zone, true);
    fsWrapper.mkdir(zone, FsPermission.getDirDefault(), true);
    final Path snap2 = fs.createSnapshot(zoneParent, "snap2");
    final Path snap2Zone = new Path(snap2, zone.getName());
    assertNull("Expected null ez path",
        dfsAdmin.getEncryptionZoneForPath(snap2Zone));

    // Create the encryption zone again
    dfsAdmin.createEncryptionZone(zone, TEST_KEY2);
    final Path snap3 = fs.createSnapshot(zoneParent, "snap3");
    final Path snap3Zone = new Path(snap3, zone.getName());
    // Check that snap3's EZ has the correct settings
    EncryptionZone ezSnap3 = dfsAdmin.getEncryptionZoneForPath(snap3Zone);
    assertEquals("Got unexpected ez path", zone.toString(),
        ezSnap3.getPath().toString());
    assertEquals("Unexpected ez key", TEST_KEY2, ezSnap3.getKeyName());
    // Check that older snapshots still have the old EZ settings
    EncryptionZone ezSnap1 = dfsAdmin.getEncryptionZoneForPath(snap1Zone);
    assertEquals("Got unexpected ez path", zone.toString(),
        ezSnap1.getPath().toString());
    assertEquals("Unexpected ez key", TEST_KEY, ezSnap1.getKeyName());

    // Check that listEZs only shows the current filesystem state
    ArrayList<EncryptionZone> listZones = Lists.newArrayList();
    RemoteIterator<EncryptionZone> it = dfsAdmin.listEncryptionZones();
    while (it.hasNext()) {
      listZones.add(it.next());
    }
    for (EncryptionZone z: listZones) {
      System.out.println(z);
    }
    assertEquals("Did not expect additional encryption zones!", 1,
        listZones.size());
    EncryptionZone listZone = listZones.get(0);
    assertEquals("Got unexpected ez path", zone.toString(),
        listZone.getPath().toString());
    assertEquals("Unexpected ez key", TEST_KEY2, listZone.getKeyName());

    // Verify contents of the snapshotted file
    final Path snapshottedZoneFile = new Path(
        snap1.toString() + "/" + zone.getName() + "/" + zoneFile.getName());
    assertEquals("Contents of snapshotted file have changed unexpectedly",
        contents, DFSTestUtil.readFile(fs, snapshottedZoneFile));

    // Now delete the snapshots out of order and verify the zones are still
    // correct
    fs.deleteSnapshot(zoneParent, snap2.getName());
    assertEquals("Got unexpected ez path", zone.toString(),
        dfsAdmin.getEncryptionZoneForPath(snap1Zone).getPath().toString());
    assertEquals("Got unexpected ez path", zone.toString(),
        dfsAdmin.getEncryptionZoneForPath(snap3Zone).getPath().toString());
    fs.deleteSnapshot(zoneParent, snap1.getName());
    assertEquals("Got unexpected ez path", zone.toString(),
        dfsAdmin.getEncryptionZoneForPath(snap3Zone).getPath().toString());
  }

  /**
   * Verify symlinks can be created in encryption zones and that
   * they function properly when the target is in the same
   * or different ez.
   */
  @Test(timeout = 60000)
  public void testEncryptionZonesWithSymlinks() throws Exception {
    // Verify we can create an encryption zone over both link and target
    final int len = 8192;
    final Path parent = new Path("/parent");
    final Path linkParent = new Path(parent, "symdir1");
    final Path targetParent = new Path(parent, "symdir2");
    final Path link = new Path(linkParent, "link");
    final Path target = new Path(targetParent, "target");
    fs.mkdirs(parent);
    dfsAdmin.createEncryptionZone(parent, TEST_KEY);
    fs.mkdirs(linkParent);
    fs.mkdirs(targetParent);
    DFSTestUtil.createFile(fs, target, len, (short)1, 0xFEED);
    String content = DFSTestUtil.readFile(fs, target);
    fs.createSymlink(target, link, false);
    assertEquals("Contents read from link are not the same as target",
        content, DFSTestUtil.readFile(fs, link));
    fs.delete(parent, true);

    // Now let's test when the symlink and target are in different
    // encryption zones
    fs.mkdirs(linkParent);
    fs.mkdirs(targetParent);
    dfsAdmin.createEncryptionZone(linkParent, TEST_KEY);
    dfsAdmin.createEncryptionZone(targetParent, TEST_KEY);
    DFSTestUtil.createFile(fs, target, len, (short)1, 0xFEED);
    content = DFSTestUtil.readFile(fs, target);
    fs.createSymlink(target, link, false);
    assertEquals("Contents read from link are not the same as target",
        content, DFSTestUtil.readFile(fs, link));
    fs.delete(link, true);
    fs.delete(target, true);
  }

  @Test(timeout = 60000)
  public void testConcatFailsInEncryptionZones() throws Exception {
    final int len = 8192;
    final Path ez = new Path("/ez");
    fs.mkdirs(ez);
    dfsAdmin.createEncryptionZone(ez, TEST_KEY);
    final Path src1 = new Path(ez, "src1");
    final Path src2 = new Path(ez, "src2");
    final Path target = new Path(ez, "target");
    DFSTestUtil.createFile(fs, src1, len, (short)1, 0xFEED);
    DFSTestUtil.createFile(fs, src2, len, (short)1, 0xFEED);
    DFSTestUtil.createFile(fs, target, len, (short)1, 0xFEED);
    try {
      fs.concat(target, new Path[] { src1, src2 });
      fail("expected concat to throw en exception for files in an ez");
    } catch (IOException e) {
      assertExceptionContains(
          "concat can not be called for files in an encryption zone", e);
    }
    fs.delete(ez, true);
  }

  /**
   * Test running the OfflineImageViewer on a system with encryption zones.
   */
  @Test(timeout = 60000)
  public void testOfflineImageViewerOnEncryptionZones() throws Exception {
    final int len = 8196;
    final Path zoneParent = new Path("/zones");
    final Path zone1 = new Path(zoneParent, "zone1");
    final Path zone1File = new Path(zone1, "file");
    fsWrapper.mkdir(zone1, FsPermission.getDirDefault(), true);
    dfsAdmin.createEncryptionZone(zone1, TEST_KEY);
    DFSTestUtil.createFile(fs, zone1File, len, (short) 1, 0xFEED);
    fs.setSafeMode(SafeModeAction.SAFEMODE_ENTER, false);
    fs.saveNamespace();

    File originalFsimage = FSImageTestUtil.findLatestImageFile(FSImageTestUtil
        .getFSImage(cluster.getNameNode()).getStorage().getStorageDir(0));
    if (originalFsimage == null) {
      throw new RuntimeException("Didn't generate or can't find fsimage");
    }

    // Run the XML OIV processor
    ByteArrayOutputStream output = new ByteArrayOutputStream();
    PrintStream pw = new PrintStream(output);
    PBImageXmlWriter v = new PBImageXmlWriter(new Configuration(), pw);
    v.visit(new RandomAccessFile(originalFsimage, "r"));
    final String xml = output.toString();
    SAXParser parser = SAXParserFactory.newInstance().newSAXParser();
    parser.parse(new InputSource(new StringReader(xml)), new DefaultHandler());
  }

  /**
   * Test creating encryption zone on the root path
   */
  @Test(timeout = 60000)
  public void testEncryptionZonesOnRootPath() throws Exception {
    final int len = 8196;
    final Path rootDir = new Path("/");
    final Path zoneFile = new Path(rootDir, "file");
    final Path rawFile = new Path("/.reserved/raw/file");
    dfsAdmin.createEncryptionZone(rootDir, TEST_KEY);
    DFSTestUtil.createFile(fs, zoneFile, len, (short) 1, 0xFEED);

    assertEquals("File can be created on the root encryption zone " +
            "with correct length",
        len, fs.getFileStatus(zoneFile).getLen());
    assertEquals("Root dir is encrypted",
        true, fs.getFileStatus(rootDir).isEncrypted());
    assertEquals("File is encrypted",
        true, fs.getFileStatus(zoneFile).isEncrypted());
    DFSTestUtil.verifyFilesNotEqual(fs, zoneFile, rawFile, len);
  }

  @Test(timeout = 60000)
  public void testEncryptionZonesOnRelativePath() throws Exception {
    final int len = 8196;
    final Path baseDir = new Path("/somewhere/base");
    final Path zoneDir = new Path("zone");
    final Path zoneFile = new Path("file");
    fs.setWorkingDirectory(baseDir);
    fs.mkdirs(zoneDir);
    dfsAdmin.createEncryptionZone(zoneDir, TEST_KEY);
    DFSTestUtil.createFile(fs, zoneFile, len, (short) 1, 0xFEED);

    assertNumZones(1);
    assertZonePresent(TEST_KEY, "/somewhere/base/zone");

    assertEquals("Got unexpected ez path", "/somewhere/base/zone", dfsAdmin
        .getEncryptionZoneForPath(zoneDir).getPath().toString());
  }
}
