HDFS-6474. Namenode needs to get the actual keys and iv from the KeyProvider. (wang)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/fs-encryption@1609833 13f79535-47bb-0310-9956-ffa450edef68

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FileEncryptionInfo.java

@@ -32,20 +32,33 @@
 public class FileEncryptionInfo {
 
   private final CipherSuite cipherSuite;
-  private final byte[] key;
+  private final byte[] edek;
   private final byte[] iv;
+  private final String ezKeyVersionName;
 
-  public FileEncryptionInfo(CipherSuite suite, byte[] key, byte[] iv) {
+  /**
+   * Create a FileEncryptionInfo.
+   *
+   * @param suite CipherSuite used to encrypt the file
+   * @param edek encrypted data encryption key (EDEK) of the file
+   * @param iv initialization vector (IV) used to encrypt the file
+   * @param ezKeyVersionName name of the KeyVersion used to encrypt the
+   *                         encrypted data encryption key.
+   */
+  public FileEncryptionInfo(final CipherSuite suite, final byte[] edek,
+      final byte[] iv, final String ezKeyVersionName) {
     checkNotNull(suite);
-    checkNotNull(key);
+    checkNotNull(edek);
     checkNotNull(iv);
-    checkArgument(key.length == suite.getAlgorithmBlockSize(),
+    checkNotNull(ezKeyVersionName);
+    checkArgument(edek.length == suite.getAlgorithmBlockSize(),
         "Unexpected key length");
     checkArgument(iv.length == suite.getAlgorithmBlockSize(),
         "Unexpected IV length");
     this.cipherSuite = suite;
-    this.key = key;
+    this.edek = edek;
     this.iv = iv;
+    this.ezKeyVersionName = ezKeyVersionName;
   }
 
   /**
@@ -57,25 +70,32 @@ public CipherSuite getCipherSuite() {
   }
 
   /**
-   * @return encrypted data encryption key for the file
+   * @return encrypted data encryption key (EDEK) for the file
    */
   public byte[] getEncryptedDataEncryptionKey() {
-    return key;
+    return edek;
   }
 
   /**
-   * @return initialization vector for the cipher used to encrypt the file
+   * @return initialization vector (IV) for the cipher used to encrypt the file
    */
   public byte[] getIV() {
     return iv;
   }
 
+  /**
+   * @return name of the encryption zone KeyVersion used to encrypt the
+   * encrypted data encryption key (EDEK).
+   */
+  public String getEzKeyVersionName() { return ezKeyVersionName; }
+
   @Override
   public String toString() {
     StringBuilder builder = new StringBuilder("{");
     builder.append("cipherSuite: " + cipherSuite);
-    builder.append(", key: " + Hex.encodeHexString(key));
+    builder.append(", edek: " + Hex.encodeHexString(edek));
     builder.append(", iv: " + Hex.encodeHexString(iv));
+    builder.append(", ezKeyVersionName: " + ezKeyVersionName);
     builder.append("}");
     return builder.toString();
   }

hadoop-hdfs-project/hadoop-hdfs/CHANGES-fs-encryption.txt

@@ -39,6 +39,9 @@ fs-encryption (Unreleased)
     HDFS-6635. Refactor encryption zone functionality into new
     EncryptionZoneManager class. (wang)
 
+    HDFS-6474. Namenode needs to get the actual keys and iv from the
+    KeyProvider. (wang)
+
   OPTIMIZATIONS
 
   BUG FIXES

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSConfigKeys.java

@@ -561,6 +561,8 @@ public class DFSConfigKeys extends CommonConfigurationKeys {
   public static final boolean DFS_ENCRYPT_DATA_TRANSFER_DEFAULT = false;
   public static final String DFS_DATA_ENCRYPTION_ALGORITHM_KEY = "dfs.encrypt.data.transfer.algorithm";
   public static final String DFS_TRUSTEDCHANNEL_RESOLVER_CLASS = "dfs.trustedchannel.resolver.class";
+  public static final String DFS_NAMENODE_KEY_VERSION_REFRESH_INTERVAL_MS_KEY = "dfs.namenode.key.version.refresh.interval.ms";
+  public static final int DFS_NAMENODE_KEY_VERSION_REFRESH_INTERVAL_MS_DEFAULT = 5*60*1000;
   
   // Journal-node related configs. These are read on the JN side.
   public static final String  DFS_JOURNALNODE_EDITS_DIR_KEY = "dfs.journalnode.edits.dir";

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/PBHelper.java

@@ -2335,6 +2335,7 @@ public static HdfsProtos.FileEncryptionInfoProto convert(
         .setSuite(convert(info.getCipherSuite()))
         .setKey(getByteString(info.getEncryptedDataEncryptionKey()))
         .setIv(getByteString(info.getIV()))
+        .setEzKeyVersionName(info.getEzKeyVersionName())
         .build();
   }
 
@@ -2346,7 +2347,8 @@ public static FileEncryptionInfo convert(
     CipherSuite suite = convert(proto.getSuite());
     byte[] key = proto.getKey().toByteArray();
     byte[] iv = proto.getIv().toByteArray();
-    return new FileEncryptionInfo(suite, key, iv);
+    String ezKeyVersionName = proto.getEzKeyVersionName();
+    return new FileEncryptionInfo(suite, key, iv, ezKeyVersionName);
   }
 
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/EncryptionZoneManager.java

@@ -3,28 +3,50 @@
 import java.io.IOException;
 import java.util.EnumSet;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
 
+import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
+import com.google.common.collect.Sets;
+import com.google.common.util.concurrent.ThreadFactoryBuilder;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.crypto.key.KeyProvider;
 import org.apache.hadoop.fs.UnresolvedLinkException;
 import org.apache.hadoop.fs.XAttr;
 import org.apache.hadoop.fs.XAttrSetFlag;
+import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.XAttrHelper;
 import org.apache.hadoop.hdfs.protocol.EncryptionZone;
 import org.apache.hadoop.hdfs.protocol.SnapshotAccessControlException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 
+import static org.apache.hadoop.crypto.key.KeyProvider.KeyVersion;
 import static org.apache.hadoop.hdfs.server.common.HdfsServerConstants
     .CRYPTO_XATTR_ENCRYPTION_ZONE;
 
 /**
- * Manages the list of encryption zones in the filesystem. Relies on the
+ * Manages the list of encryption zones in the filesystem.
- * FSDirectory lock for synchronization.
+ * <p/>
+ * The EncryptionZoneManager has its own lock, but relies on the FSDirectory
+ * lock being held for many operations. The FSDirectory lock should not be
+ * taken if the manager lock is already held.
  */
 public class EncryptionZoneManager {
 
+  public static Logger LOG = LoggerFactory.getLogger(EncryptionZoneManager
+      .class);
+
   /**
    * EncryptionZoneInt is the internal representation of an encryption zone. The
    * external representation of an EZ is embodied in an EncryptionZone and
@@ -34,9 +56,30 @@ private class EncryptionZoneInt {
     private final String keyId;
     private final long inodeId;
 
+    private final HashSet<KeyVersion> keyVersions;
+    private KeyVersion latestVersion;
+
     EncryptionZoneInt(long inodeId, String keyId) {
       this.keyId = keyId;
       this.inodeId = inodeId;
+      keyVersions = Sets.newHashSet();
+      latestVersion = null;
+    }
+
+    KeyVersion getLatestKeyVersion() {
+      return latestVersion;
+    }
+
+    void addKeyVersion(KeyVersion version) {
+      Preconditions.checkNotNull(version);
+      if (!keyVersions.contains(version)) {
+        LOG.debug("Key {} has new key version {}", keyId, version);
+        keyVersions.add(version);
+      }
+      // Always set the latestVersion to not get stuck on an old version in
+      // racy situations. Should eventually converge thanks to the
+      // monitor.
+      latestVersion = version;
     }
 
     String getKeyId() {
@@ -47,49 +90,265 @@ long getINodeId() {
       return inodeId;
     }
 
-    String getFullPathName() {
+  }
-      return dir.getInode(inodeId).getFullPathName();
+
-    }
+  /**
+   * Protects the <tt>encryptionZones</tt> map and its contents.
+   */
+  private final ReentrantReadWriteLock lock;
+
+  private void readLock() {
+    lock.readLock().lock();
+  }
+
+  private void readUnlock() {
+    lock.readLock().unlock();
+  }
+
+  private void writeLock() {
+    lock.writeLock().lock();
+  }
+
+  private void writeUnlock() {
+    lock.writeLock().unlock();
+  }
+
+  public boolean hasWriteLock() {
+    return lock.isWriteLockedByCurrentThread();
+  }
+
+  public boolean hasReadLock() {
+    return lock.getReadHoldCount() > 0 || hasWriteLock();
   }
 
   private final Map<Long, EncryptionZoneInt> encryptionZones;
-
   private final FSDirectory dir;
+  private final ScheduledExecutorService monitor;
+  private final KeyProvider provider;
 
   /**
    * Construct a new EncryptionZoneManager.
    *
    * @param dir Enclosing FSDirectory
    */
-  public EncryptionZoneManager(FSDirectory dir) {
+  public EncryptionZoneManager(FSDirectory dir, Configuration conf,
+      KeyProvider provider) {
+
     this.dir = dir;
+    this.provider = provider;
+    lock = new ReentrantReadWriteLock();
     encryptionZones = new HashMap<Long, EncryptionZoneInt>();
+
+    monitor = Executors.newScheduledThreadPool(1,
+        new ThreadFactoryBuilder()
+            .setDaemon(true)
+            .setNameFormat(EncryptionZoneMonitor.class.getSimpleName() + "-%d")
+            .build());
+    final int refreshMs = conf.getInt(
+        DFSConfigKeys.DFS_NAMENODE_KEY_VERSION_REFRESH_INTERVAL_MS_KEY,
+        DFSConfigKeys.DFS_NAMENODE_KEY_VERSION_REFRESH_INTERVAL_MS_DEFAULT
+    );
+    Preconditions.checkArgument(refreshMs >= 0, "%s cannot be negative",
+        DFSConfigKeys.DFS_NAMENODE_KEY_VERSION_REFRESH_INTERVAL_MS_KEY);
+    monitor.scheduleAtFixedRate(new EncryptionZoneMonitor(), 0, refreshMs,
+        TimeUnit.MILLISECONDS);
+  }
+
+  /**
+   * Periodically wakes up to fetch the latest version of each encryption
+   * zone key.
+   */
+  private class EncryptionZoneMonitor implements Runnable {
+    @Override
+    public void run() {
+      LOG.debug("Monitor waking up to refresh encryption zone key versions");
+      HashMap<Long, String> toFetch = Maps.newHashMap();
+      HashMap<Long, KeyVersion> toUpdate =
+          Maps.newHashMap();
+      // Determine the keyIds to fetch
+      readLock();
+      try {
+        for (EncryptionZoneInt ezi : encryptionZones.values()) {
+          toFetch.put(ezi.getINodeId(), ezi.getKeyId());
+        }
+      } finally {
+        readUnlock();
+      }
+      LOG.trace("Found {} keys to check", toFetch.size());
+      // Fetch the key versions while not holding the lock
+      for (Map.Entry<Long, String> entry : toFetch.entrySet()) {
+        try {
+          KeyVersion version = provider.getCurrentKey(entry.getValue());
+          toUpdate.put(entry.getKey(), version);
+        } catch (IOException e) {
+          LOG.warn("Error while getting the current key for {} {}",
+              entry.getValue(), e);
+        }
+      }
+      LOG.trace("Fetched {} key versions from KeyProvider", toUpdate.size());
+      // Update the key versions for each encryption zone
+      writeLock();
+      try {
+        for (Map.Entry<Long, KeyVersion> entry : toUpdate.entrySet()) {
+          EncryptionZoneInt ezi = encryptionZones.get(entry.getKey());
+          // zone might have been removed in the intervening time
+          if (ezi == null) {
+            continue;
+          }
+          ezi.addKeyVersion(entry.getValue());
+        }
+      } finally {
+        writeUnlock();
+      }
+    }
+  }
+
+  /**
+   * Forces the EncryptionZoneMonitor to run, waiting until completion.
+   */
+  @VisibleForTesting
+  public void kickMonitor() throws Exception {
+    Future future = monitor.submit(new EncryptionZoneMonitor());
+    future.get();
+  }
+
+  /**
+   * Immediately fetches the latest KeyVersion for an encryption zone,
+   * also updating the encryption zone.
+   *
+   * @param iip of the encryption zone
+   * @return latest KeyVersion
+   * @throws IOException on KeyProvider error
+   */
+  KeyVersion updateLatestKeyVersion(INodesInPath iip) throws IOException {
+    EncryptionZoneInt ezi;
+    readLock();
+    try {
+      ezi = getEncryptionZoneForPath(iip);
+    } finally {
+      readUnlock();
+    }
+    if (ezi == null) {
+      throw new IOException("Cannot update KeyVersion since iip is not within" +
+          " an encryption zone");
+    }
+
+    // Do not hold the lock while doing KeyProvider operations
+    KeyVersion version = provider.getCurrentKey(ezi.getKeyId());
+
+    writeLock();
+    try {
+      ezi.addKeyVersion(version);
+      return version;
+    } finally {
+      writeUnlock();
+    }
   }
 
   /**
    * Add a new encryption zone.
+   * <p/>
+   * Called while holding the FSDirectory lock.
    *
    * @param inodeId of the encryption zone
    * @param keyId   encryption zone key id
    */
   void addEncryptionZone(Long inodeId, String keyId) {
+    assert dir.hasWriteLock();
     final EncryptionZoneInt ez = new EncryptionZoneInt(inodeId, keyId);
-    encryptionZones.put(inodeId, ez);
+    writeLock();
+    try {
+      encryptionZones.put(inodeId, ez);
+    } finally {
+      writeUnlock();
+    }
   }
 
+  /**
+   * Remove an encryption zone.
+   * <p/>
+   * Called while holding the FSDirectory lock.
+   */
   void removeEncryptionZone(Long inodeId) {
-    encryptionZones.remove(inodeId);
+    assert dir.hasWriteLock();
+    writeLock();
+    try {
+      encryptionZones.remove(inodeId);
+    } finally {
+      writeUnlock();
+    }
   }
 
   /**
    * Returns true if an IIP is within an encryption zone.
+   * <p/>
+   * Called while holding the FSDirectory lock.
    */
   boolean isInAnEZ(INodesInPath iip)
       throws UnresolvedLinkException, SnapshotAccessControlException {
-    return (getEncryptionZoneForPath(iip) != null);
+    assert dir.hasReadLock();
+    readLock();
+    try {
+      return (getEncryptionZoneForPath(iip) != null);
+    } finally {
+      readUnlock();
+    }
   }
 
+  /**
+   * Returns the path of the EncryptionZoneInt.
+   * <p/>
+   * Called while holding the FSDirectory lock.
+   */
+  private String getFullPathName(EncryptionZoneInt ezi) {
+    assert dir.hasReadLock();
+    return dir.getInode(ezi.getINodeId()).getFullPathName();
+  }
+
+  KeyVersion getLatestKeyVersion(final INodesInPath iip) {
+    readLock();
+    try {
+      EncryptionZoneInt ezi = getEncryptionZoneForPath(iip);
+      if (ezi == null) {
+        return null;
+      }
+      return ezi.getLatestKeyVersion();
+    } finally {
+      readUnlock();
+    }
+  }
+
+  /**
+   * @return true if the provided <tt>keyVersionName</tt> is the name of a
+   * valid KeyVersion for the encryption zone of <tt>iip</tt>,
+   * and <tt>iip</tt> is within an encryption zone.
+   */
+  boolean isValidKeyVersion(final INodesInPath iip, String keyVersionName) {
+    readLock();
+    try {
+      EncryptionZoneInt ezi = getEncryptionZoneForPath(iip);
+      if (ezi == null) {
+        return false;
+      }
+      for (KeyVersion ezVersion : ezi.keyVersions) {
+        if (keyVersionName.equals(ezVersion.getVersionName())) {
+          return true;
+        }
+      }
+      return false;
+    } finally {
+      readUnlock();
+    }
+  }
+
+  /**
+   * Looks up the EncryptionZoneInt for a path within an encryption zone.
+   * Returns null if path is not within an EZ.
+   * <p/>
+   * Must be called while holding the manager lock.
+   */
   private EncryptionZoneInt getEncryptionZoneForPath(INodesInPath iip) {
+    assert hasReadLock();
     Preconditions.checkNotNull(iip);
     final INode[] inodes = iip.getINodes();
     for (int i = inodes.length - 1; i >= 0; i--) {
@@ -105,8 +364,10 @@ private EncryptionZoneInt getEncryptionZoneForPath(INodesInPath iip) {
   }
 
   /**
-   * Throws an exception if the provided inode cannot be renamed into the
+   * Throws an exception if the provided path cannot be renamed into the
    * destination because of differing encryption zones.
+   * <p/>
+   * Called while holding the FSDirectory lock.
    *
    * @param srcIIP source IIP
    * @param dstIIP destination IIP
@@ -115,66 +376,101 @@ private EncryptionZoneInt getEncryptionZoneForPath(INodesInPath iip) {
    */
   void checkMoveValidity(INodesInPath srcIIP, INodesInPath dstIIP, String src)
       throws IOException {
-    final boolean srcInEZ = (getEncryptionZoneForPath(srcIIP) != null);
+    assert dir.hasReadLock();
-    final boolean dstInEZ = (getEncryptionZoneForPath(dstIIP) != null);
+    readLock();
-    if (srcInEZ) {
+    try {
-      if (!dstInEZ) {
-        throw new IOException(src + " can't be moved from an encryption zone.");
-      }
-    } else {
-      if (dstInEZ) {
-        throw new IOException(src + " can't be moved into an encryption zone.");
-      }
-    }
-
-    if (srcInEZ || dstInEZ) {
       final EncryptionZoneInt srcEZI = getEncryptionZoneForPath(srcIIP);
       final EncryptionZoneInt dstEZI = getEncryptionZoneForPath(dstIIP);
-      Preconditions.checkArgument(srcEZI != null, "couldn't find src EZ?");
+      final boolean srcInEZ = (srcEZI != null);
-      Preconditions.checkArgument(dstEZI != null, "couldn't find dst EZ?");
+      final boolean dstInEZ = (dstEZI != null);
-      if (srcEZI != dstEZI) {
+      if (srcInEZ) {
-        final String srcEZPath = srcEZI.getFullPathName();
+        if (!dstInEZ) {
-        final String dstEZPath = dstEZI.getFullPathName();
+          throw new IOException(
-        final StringBuilder sb = new StringBuilder(src);
+              src + " can't be moved from an encryption zone.");
-        sb.append(" can't be moved from encryption zone ");
+        }
-        sb.append(srcEZPath);
+      } else {
-        sb.append(" to encryption zone ");
+        if (dstInEZ) {
-        sb.append(dstEZPath);
+          throw new IOException(
-        sb.append(".");
+              src + " can't be moved into an encryption zone.");
-        throw new IOException(sb.toString());
+        }
       }
+
+      if (srcInEZ || dstInEZ) {
+        Preconditions.checkState(srcEZI != null, "couldn't find src EZ?");
+        Preconditions.checkState(dstEZI != null, "couldn't find dst EZ?");
+        if (srcEZI != dstEZI) {
+          final String srcEZPath = getFullPathName(srcEZI);
+          final String dstEZPath = getFullPathName(dstEZI);
+          final StringBuilder sb = new StringBuilder(src);
+          sb.append(" can't be moved from encryption zone ");
+          sb.append(srcEZPath);
+          sb.append(" to encryption zone ");
+          sb.append(dstEZPath);
+          sb.append(".");
+          throw new IOException(sb.toString());
+        }
+      }
+    } finally {
+      readUnlock();
     }
   }
 
-  XAttr createEncryptionZone(String src, String keyId) throws IOException {
+  /**
-    if (dir.isNonEmptyDirectory(src)) {
+   * Create a new encryption zone.
-      throw new IOException(
+   * <p/>
-          "Attempt to create an encryption zone for a non-empty directory.");
+   * Called while holding the FSDirectory lock.
-    }
+   */
+  XAttr createEncryptionZone(String src, String keyId, KeyVersion keyVersion)
+      throws IOException {
+    assert dir.hasWriteLock();
+    writeLock();
+    try {
+      if (dir.isNonEmptyDirectory(src)) {
+        throw new IOException(
+            "Attempt to create an encryption zone for a non-empty directory.");
+      }
 
-    final INodesInPath srcIIP = dir.getINodesInPath4Write(src, false);
+      final INodesInPath srcIIP = dir.getINodesInPath4Write(src, false);
-    final EncryptionZoneInt ezi = getEncryptionZoneForPath(srcIIP);
+      EncryptionZoneInt ezi = getEncryptionZoneForPath(srcIIP);
-    if (ezi != null) {
+      if (ezi != null) {
-      throw new IOException("Directory " + src +
+        throw new IOException("Directory " + src + " is already in an " +
-          " is already in an encryption zone. (" + ezi.getFullPathName() + ")");
+            "encryption zone. (" + getFullPathName(ezi) + ")");
-    }
+      }
 
-    final XAttr keyIdXAttr =
+      final XAttr keyIdXAttr = XAttrHelper
-        XAttrHelper.buildXAttr(CRYPTO_XATTR_ENCRYPTION_ZONE, keyId.getBytes());
+          .buildXAttr(CRYPTO_XATTR_ENCRYPTION_ZONE, keyId.getBytes());
-    final List<XAttr> xattrs = Lists.newArrayListWithCapacity(1);
+
-    xattrs.add(keyIdXAttr);
+      final List<XAttr> xattrs = Lists.newArrayListWithCapacity(1);
-    final INode inode =
+      xattrs.add(keyIdXAttr);
-        dir.unprotectedSetXAttrs(src, xattrs, EnumSet.of(XAttrSetFlag.CREATE));
+      // updating the xattr will call addEncryptionZone,
-    addEncryptionZone(inode.getId(), keyId);
+      // done this way to handle edit log loading
-    return keyIdXAttr;
+      dir.unprotectedSetXAttrs(src, xattrs, EnumSet.of(XAttrSetFlag.CREATE));
+      // Re-get the new encryption zone add the latest key version
+      ezi = getEncryptionZoneForPath(srcIIP);
+      ezi.addKeyVersion(keyVersion);
+      return keyIdXAttr;
+    } finally {
+      writeUnlock();
+    }
   }
 
+  /**
+   * Return the current list of encryption zones.
+   * <p/>
+   * Called while holding the FSDirectory lock.
+   */
   List<EncryptionZone> listEncryptionZones() throws IOException {
-    final List<EncryptionZone> ret =
+    assert dir.hasReadLock();
-        Lists.newArrayListWithExpectedSize(encryptionZones.size());
+    readLock();
-    for (EncryptionZoneInt ezi : encryptionZones.values()) {
+    try {
-      ret.add(new EncryptionZone(ezi.getFullPathName(), ezi.getKeyId()));
+      final List<EncryptionZone> ret =
+          Lists.newArrayListWithExpectedSize(encryptionZones.size());
+      for (EncryptionZoneInt ezi : encryptionZones.values()) {
+        ret.add(new EncryptionZone(getFullPathName(ezi), ezi.getKeyId()));
+      }
+      return ret;
+    } finally {
+      readUnlock();
     }
-    return ret;
   }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirectory.java

@@ -17,6 +17,7 @@
  */
 package org.apache.hadoop.hdfs.server.namenode;
 
+import static org.apache.hadoop.crypto.key.KeyProvider.KeyVersion;
 import static org.apache.hadoop.hdfs.server.common.HdfsServerConstants.CRYPTO_XATTR_ENCRYPTION_ZONE;
 import static org.apache.hadoop.hdfs.server.common.HdfsServerConstants.CRYPTO_XATTR_FILE_ENCRYPTION_INFO;
 import static org.apache.hadoop.util.Time.now;
@@ -35,6 +36,7 @@
 import org.apache.hadoop.HadoopIllegalArgumentException;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.crypto.key.KeyProvider;
 import org.apache.hadoop.fs.ContentSummary;
 import org.apache.hadoop.fs.FileAlreadyExistsException;
 import org.apache.hadoop.fs.FileEncryptionInfo;
@@ -162,7 +164,7 @@ boolean hasWriteLock() {
   }
 
   boolean hasReadLock() {
-    return this.dirLock.getReadHoldCount() > 0;
+    return this.dirLock.getReadHoldCount() > 0 || hasWriteLock();
   }
 
   public int getReadHoldCount() {
@@ -173,7 +175,8 @@ public int getWriteHoldCount() {
     return this.dirLock.getWriteHoldCount();
   }
 
-  final EncryptionZoneManager ezManager;
+  @VisibleForTesting
+  public final EncryptionZoneManager ezManager;
 
   /**
    * Caches frequently used file names used in {@link INode} to reuse 
@@ -224,7 +227,7 @@ public int getWriteHoldCount() {
     nameCache = new NameCache<ByteArray>(threshold);
     namesystem = ns;
 
-    ezManager = new EncryptionZoneManager(this);
+    ezManager = new EncryptionZoneManager(this, conf, ns.getProvider());
   }
     
   private FSNamesystem getFSNamesystem() {
@@ -905,16 +908,6 @@ void updateQuotasInSourceTree() throws QuotaExceededException {
     }
   }
 
-  boolean isInAnEZ(INodesInPath iip)
-    throws UnresolvedLinkException, SnapshotAccessControlException {
-    readLock();
-    try {
-      return ezManager.isInAnEZ(iip);
-    } finally {
-      readUnlock();
-    }
-  }
-
   /**
    * Set file replication
    * 
@@ -2618,12 +2611,46 @@ List<XAttr> filterINodeXAttrs(final List<XAttr> existingXAttrs,
 
     return newXAttrs;
   }
-  
+
-  XAttr createEncryptionZone(String src, String keyId)
+  boolean isInAnEZ(INodesInPath iip)
+      throws UnresolvedLinkException, SnapshotAccessControlException {
+    readLock();
+    try {
+      return ezManager.isInAnEZ(iip);
+    } finally {
+      readUnlock();
+    }
+  }
+
+  KeyVersion getLatestKeyVersion(INodesInPath iip) {
+    readLock();
+    try {
+      return ezManager.getLatestKeyVersion(iip);
+    } finally {
+      readUnlock();
+    }
+  }
+
+  KeyVersion updateLatestKeyVersion(INodesInPath iip) throws
+      IOException {
+    // No locking, this operation does not involve any FSDirectory operations
+    return ezManager.updateLatestKeyVersion(iip);
+  }
+
+  boolean isValidKeyVersion(INodesInPath iip, String keyVersionName) {
+    readLock();
+    try {
+      return ezManager.isValidKeyVersion(iip, keyVersionName);
+    } finally {
+      readUnlock();
+    }
+  }
+
+  XAttr createEncryptionZone(String src, String keyId, KeyVersion keyVersion)
     throws IOException {
     writeLock();
     try {
-      return ezManager.createEncryptionZone(src, keyId);
+      return ezManager.createEncryptionZone(src, keyId, keyVersion);
     } finally {
       writeUnlock();
     }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java

@@ -17,6 +17,7 @@
  */
 package org.apache.hadoop.hdfs.server.namenode;
 
+import static org.apache.hadoop.crypto.key.KeyProvider.KeyVersion;
 import static org.apache.hadoop.fs.CommonConfigurationKeysPublic.FS_TRASH_INTERVAL_DEFAULT;
 import static org.apache.hadoop.fs.CommonConfigurationKeysPublic.FS_TRASH_INTERVAL_KEY;
 import static org.apache.hadoop.fs.CommonConfigurationKeysPublic.IO_FILE_BUFFER_SIZE_DEFAULT;
@@ -100,6 +101,7 @@
 import java.lang.management.ManagementFactory;
 import java.net.InetAddress;
 import java.net.URI;
+import java.security.GeneralSecurityException;
 import java.security.NoSuchAlgorithmException;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -133,6 +135,7 @@
 import org.apache.hadoop.crypto.CipherSuite;
 import org.apache.hadoop.crypto.CryptoCodec;
 import org.apache.hadoop.crypto.key.KeyProvider;
+import org.apache.hadoop.crypto.key.KeyProviderCryptoExtension;
 import org.apache.hadoop.crypto.key.KeyProviderFactory;
 import org.apache.hadoop.fs.BatchedRemoteIterator.BatchedListEntries;
 import org.apache.hadoop.fs.CacheFlag;
@@ -533,7 +536,7 @@ private void logAuditEvent(boolean succeeded,
 
   private final NNConf nnConf;
 
-  private KeyProvider provider = null;
+  private KeyProviderCryptoExtension provider = null;
   private KeyProvider.Options providerOptions = null;
 
   private final CryptoCodec codec;
@@ -929,7 +932,8 @@ private void initializeKeyProvider(final Configuration conf) {
         LOG.error(err);
         throw new RuntimeException(err);
       }
-      provider = providers.get(0);
+      provider = KeyProviderCryptoExtension
+          .createKeyProviderCryptoExtension(providers.get(0));
       if (provider.isTransient()) {
         final String err =
             "A KeyProvider was found but it is a transient provider.";
@@ -2310,7 +2314,7 @@ private void verifyParentDir(String src) throws FileNotFoundException,
    * CipherSuite from the list provided by the client. Since the client may 
    * be newer, need to handle unknown CipherSuites.
    *
-   * @param src path of the file
+   * @param srcIIP path of the file
    * @param cipherSuites client-provided list of supported CipherSuites, 
    *                     in desired order.
    * @return chosen CipherSuite, or null if file is not in an EncryptionZone
@@ -2349,6 +2353,62 @@ private CipherSuite chooseCipherSuite(INodesInPath srcIIP, List<CipherSuite>
     return chosen;
   }
 
+  /**
+   * Create a new FileEncryptionInfo for a path. Also chooses an
+   * appropriate CipherSuite to use from the list provided by the
+   * client.
+   *
+   * @param src Target path
+   * @param pathComponents Target path split up into path components
+   * @param cipherSuites List of CipherSuites provided by the client
+   * @return a new FileEncryptionInfo, or null if path is not within an
+   * encryption
+   * zone.
+   * @throws IOException
+   */
+  private FileEncryptionInfo newFileEncryptionInfo(String src,
+      byte[][] pathComponents, List<CipherSuite> cipherSuites)
+      throws IOException {
+    INodesInPath iip = null;
+    CipherSuite suite = null;
+    KeyVersion latestEZKeyVersion = null;
+    readLock();
+    try {
+      src = FSDirectory.resolvePath(src, pathComponents, dir);
+      iip = dir.getINodesInPath4Write(src);
+      // Nothing to do if the path is not within an EZ
+      if (!dir.isInAnEZ(iip)) {
+        return null;
+      }
+      suite = chooseCipherSuite(iip, cipherSuites);
+      if (suite != null) {
+        Preconditions.checkArgument(!suite.equals(CipherSuite.UNKNOWN),
+            "Chose an UNKNOWN CipherSuite!");
+      }
+      latestEZKeyVersion = dir.getLatestKeyVersion(iip);
+    } finally {
+      readUnlock();
+    }
+
+    // If the latest key version is null, need to fetch it and update
+    if (latestEZKeyVersion == null) {
+      latestEZKeyVersion = dir.updateLatestKeyVersion(iip);
+    }
+    Preconditions.checkState(latestEZKeyVersion != null);
+
+    // Generate the EDEK while not holding the lock
+    KeyProviderCryptoExtension.EncryptedKeyVersion edek = null;
+    try {
+      edek = provider.generateEncryptedKey(latestEZKeyVersion);
+    } catch (GeneralSecurityException e) {
+      throw new IOException(e);
+    }
+    Preconditions.checkNotNull(edek);
+
+    return new FileEncryptionInfo(suite, edek.getEncryptedKey().getMaterial(),
+        edek.getIv(), edek.getKeyVersionName());
+  }
+
   /**
    * Create a new file entry in the namespace.
    * 
@@ -2426,26 +2486,62 @@ private HdfsFileStatus startFileInt(String src, PermissionStatus permissions,
     boolean overwrite = flag.contains(CreateFlag.OVERWRITE);
 
     waitForLoadingFSImage();
-    writeLock();
+
+    /*
+     * We want to avoid holding any locks while creating a new
+     * FileEncryptionInfo, since this can be very slow. Since the path can
+     * flip flop between being in an encryption zone and not in the meantime,
+     * we need to recheck the preconditions and generate a new
+     * FileEncryptionInfo in some circumstances.
+     *
+     * A special RetryStartFileException is used to indicate that we should
+     * retry creation of a FileEncryptionInfo.
+     */
     try {
-      checkOperation(OperationCategory.WRITE);
+      boolean shouldContinue = true;
-      checkNameNodeSafeMode("Cannot create file" + src);
+      int iters = 0;
-      src = FSDirectory.resolvePath(src, pathComponents, dir);
+      while (shouldContinue) {
-      startFileInternal(pc, src, permissions, holder, clientMachine, create,
+        skipSync = false;
-          overwrite, createParent, replication, blockSize, cipherSuites,
+        if (iters >= 10) {
-          logRetryCache);
+          throw new IOException("Too many retries because of encryption zone " +
-      stat = dir.getFileInfo(src, false);
+              "operations, something might be broken!");
-    } catch (StandbyException se) {
+        }
-      skipSync = true;
+        shouldContinue = false;
-      throw se;
+        iters++;
+        // Optimistically generate a FileEncryptionInfo for this path.
+        FileEncryptionInfo feInfo =
+            newFileEncryptionInfo(src, pathComponents, cipherSuites);
+
+        // Try to create the file with this feInfo
+        writeLock();
+        try {
+          checkOperation(OperationCategory.WRITE);
+          checkNameNodeSafeMode("Cannot create file" + src);
+          src = FSDirectory.resolvePath(src, pathComponents, dir);
+          startFileInternal(pc, src, permissions, holder, clientMachine, create,
+              overwrite, createParent, replication, blockSize, feInfo,
+              logRetryCache);
+          stat = dir.getFileInfo(src, false);
+        } catch (StandbyException se) {
+          skipSync = true;
+          throw se;
+        } catch (RetryStartFileException e) {
+          shouldContinue = true;
+          if (LOG.isTraceEnabled()) {
+            LOG.trace("Preconditions failed, retrying creation of " +
+                    "FileEncryptionInfo", e);
+          }
+        } finally {
+          writeUnlock();
+        }
+      }
     } finally {
-      writeUnlock();
       // There might be transactions logged while trying to recover the lease.
       // They need to be sync'ed even when an exception was thrown.
       if (!skipSync) {
         getEditLog().logSync();
       }
-    } 
+    }
 
     logAuditEvent(true, "create", src, null, stat);
     return stat;
@@ -2463,11 +2559,11 @@ private HdfsFileStatus startFileInt(String src, PermissionStatus permissions,
   private void startFileInternal(FSPermissionChecker pc, String src,
       PermissionStatus permissions, String holder, String clientMachine,
       boolean create, boolean overwrite, boolean createParent,
-      short replication, long blockSize, List<CipherSuite> cipherSuites,
+      short replication, long blockSize, FileEncryptionInfo feInfo,
       boolean logRetryEntry)
       throws FileAlreadyExistsException, AccessControlException,
       UnresolvedLinkException, FileNotFoundException,
-      ParentNotDirectoryException, IOException {
+      ParentNotDirectoryException, RetryStartFileException, IOException {
     assert hasWriteLock();
     // Verify that the destination does not exist as a directory already.
     final INodesInPath iip = dir.getINodesInPath4Write(src);
@@ -2477,22 +2573,21 @@ private void startFileInternal(FSPermissionChecker pc, String src,
           " already exists as a directory");
     }
 
-    FileEncryptionInfo feInfo = null;
+    if (!dir.isInAnEZ(iip)) {
-    CipherSuite suite = chooseCipherSuite(iip, cipherSuites);
+      // If the path is not in an EZ, we don't need an feInfo.
-    if (suite != null) {
+      // Null it out in case one was already generated.
-      Preconditions.checkArgument(!suite.equals(CipherSuite.UNKNOWN), 
+      feInfo = null;
-          "Chose an UNKNOWN CipherSuite!");
+    } else {
-      // TODO: fill in actual key/iv in HDFS-6474
+      // The path is now within an EZ, but no feInfo. Retry.
-      // For now, populate with dummy data
+      if (feInfo == null) {
-      byte[] key = new byte[suite.getAlgorithmBlockSize()];
+        throw new RetryStartFileException();
-      for (int i = 0; i < key.length; i++) {
-        key[i] = (byte)i;
       }
-      byte[] iv = new byte[suite.getAlgorithmBlockSize()];
+      // It's in an EZ and we have a provided feInfo. Make sure the
-      for (int i = 0; i < iv.length; i++) {
+      // keyVersion of the encryption key used matches one of the keyVersions of
-        iv[i] = (byte)(3+i*2);
+      // the key of the encryption zone.
+      if (!dir.isValidKeyVersion(iip, feInfo.getEzKeyVersionName())) {
+        throw new RetryStartFileException();
       }
-      feInfo = new FileEncryptionInfo(suite, key, iv);
     }
 
     final INodeFile myFile = INodeFile.valueOf(inode, src, true);
@@ -8319,12 +8414,14 @@ void createEncryptionZone(final String src, String keyIdArg)
     String keyId = keyIdArg;
     boolean success = false;
     try {
+      KeyVersion keyVersion;
       if (keyId == null || keyId.isEmpty()) {
-        keyId = createNewKey(src);
+        keyId = UUID.randomUUID().toString();
+        keyVersion = createNewKey(keyId, src);
         createdKey = true;
       } else {
-        if (provider.getCurrentKey(keyId) == null) {
+        keyVersion = provider.getCurrentKey(keyId);
-
+        if (keyVersion == null) {
           /*
            * It would be nice if we threw something more specific than
            * IOException when the key is not found, but the KeyProvider API
@@ -8336,7 +8433,7 @@ void createEncryptionZone(final String src, String keyIdArg)
           throw new IOException("Key " + keyId + " doesn't exist.");
         }
       }
-      createEncryptionZoneInt(src, keyId, cacheEntry != null);
+      createEncryptionZoneInt(src, keyId, keyVersion, cacheEntry != null);
       success = true;
     } catch (AccessControlException e) {
       logAuditEvent(false, "createEncryptionZone", src);
@@ -8351,7 +8448,8 @@ void createEncryptionZone(final String src, String keyIdArg)
   }
 
   private void createEncryptionZoneInt(final String srcArg, String keyId,
-    final boolean logRetryCache) throws IOException {
+    final KeyVersion keyVersion, final boolean logRetryCache) throws
+      IOException {
     String src = srcArg;
     HdfsFileStatus resultingStat = null;
     checkSuperuserPrivilege();
@@ -8365,7 +8463,7 @@ private void createEncryptionZoneInt(final String srcArg, String keyId,
       checkNameNodeSafeMode("Cannot create encryption zone on " + src);
       src = FSDirectory.resolvePath(src, pathComponents, dir);
 
-      final XAttr keyIdXAttr = dir.createEncryptionZone(src, keyId);
+      final XAttr keyIdXAttr = dir.createEncryptionZone(src, keyId, keyVersion);
       List<XAttr> xAttrs = Lists.newArrayListWithCapacity(1);
       xAttrs.add(keyIdXAttr);
       getEditLog().logSetXAttrs(src, xAttrs, logRetryCache);
@@ -8377,19 +8475,29 @@ private void createEncryptionZoneInt(final String srcArg, String keyId,
     logAuditEvent(true, "createEncryptionZone", src, null, resultingStat);
   }
 
-  private String createNewKey(String src)
+  /**
+   * Create a new key on the KeyProvider for an encryption zone.
+   *
+   * @param keyId id of the key
+   * @param src path of the encryption zone.
+   * @return KeyVersion of the created key
+   * @throws IOException
+   */
+  private KeyVersion createNewKey(String keyId, String src)
     throws IOException {
-    final String keyId = UUID.randomUUID().toString();
+    Preconditions.checkNotNull(keyId);
+    Preconditions.checkNotNull(src);
     // TODO pass in hdfs://HOST:PORT (HDFS-6490)
     providerOptions.setDescription(src);
     providerOptions.setBitLength(codec.getCipherSuite()
         .getAlgorithmBlockSize()*8);
+    KeyVersion version = null;
     try {
-      provider.createKey(keyId, providerOptions);
+      version = provider.createKey(keyId, providerOptions);
     } catch (NoSuchAlgorithmException e) {
       throw new IOException(e);
     }
-    return keyId;
+    return version;
   }
 
   List<EncryptionZone> listEncryptionZones() throws IOException {

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/RetryStartFileException.java

@@ -0,0 +1,21 @@
+/**
+ * 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.server.namenode;
+
+public class RetryStartFileException extends Exception {
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/proto/hdfs.proto

@@ -184,6 +184,7 @@ message FileEncryptionInfoProto {
   required CipherSuite suite = 1;
   required bytes key = 2;
   required bytes iv = 3;
+  required string ezKeyVersionName = 4;
 }
 
 /**

hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml

@@ -2008,4 +2008,15 @@
   </description>
 </property>
 
+<property>
+  <name>dfs.namenode.key.version.refresh.interval.ms</name>
+  <value>300000</value>
+  <description>How frequently the namenode will attempt to fetch the latest
+      key version of encryption zone keys from the configured KeyProvider, in
+      milliseconds. New key versions are created when a key is rolled. This
+      setting thus controls the window of staleness where an old key version
+      is used after a key is rolled.
+  </description>
+</property>
+
 </configuration>

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestEncryptionZonesAPI.java

@@ -21,17 +21,20 @@
 import java.io.IOException;
 import java.security.NoSuchAlgorithmException;
 import java.security.PrivilegedExceptionAction;
+import java.util.Arrays;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 import java.util.UUID;
 
+import com.google.common.base.Preconditions;
 import com.google.common.collect.Lists;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.crypto.CipherSuite;
 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.FSDataInputStream;
 import org.apache.hadoop.fs.FileEncryptionInfo;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
@@ -39,16 +42,20 @@
 import org.apache.hadoop.hdfs.client.HdfsAdmin;
 import org.apache.hadoop.hdfs.protocol.EncryptionZone;
 import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
+import org.apache.hadoop.hdfs.server.namenode.EncryptionZoneManager;
 import org.apache.hadoop.security.AccessControlException;
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.test.GenericTestUtils;
+import org.apache.log4j.Level;
+import org.apache.log4j.Logger;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
 
-import com.google.common.base.Preconditions;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.fail;
 
 public class TestEncryptionZonesAPI {
@@ -71,6 +78,7 @@ public void setUpCluster() throws IOException {
         JavaKeyStoreProvider.SCHEME_NAME + "://file" + tmpDir + "/test.jks");
     cluster = new MiniDFSCluster.Builder(conf).numDataNodes(1).build();
     fs = (DistributedFileSystem) createFileSystem(conf);
+    Logger.getLogger(EncryptionZoneManager.class).setLevel(Level.TRACE);
   }
 
   protected FileSystem createFileSystem(Configuration conf) throws IOException {
@@ -382,21 +390,80 @@ public void testCipherSuiteNegotiation() throws Exception {
     fs.getClient().cipherSuites.add(CipherSuite.AES_CTR_NOPADDING);
     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.getProviders(conf).get(0);
+    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++) {
-      LocatedBlocks blocks =
+      FileEncryptionInfo feInfo =
-          fs.getClient().getLocatedBlocks(zone.toString() + "/success2", 0);
+          getFileEncryptionInfo(new Path(zone.toString() +
-      FileEncryptionInfo feInfo = blocks.getFileEncryptionInfo();
+              "/success" + i));
       assertEquals(feInfo.getCipherSuite(), CipherSuite.AES_CTR_NOPADDING);
-      // TODO: validate against actual key/iv in HDFS-6474
-      byte[] key = feInfo.getEncryptedDataEncryptionKey();
-      for (int j = 0; j < key.length; j++) {
-        assertEquals("Unexpected key byte", (byte)j, key[j]);
-      }
-      byte[] iv = feInfo.getIV();
-      for (int j = 0; j < iv.length; j++) {
-        assertEquals("Unexpected IV byte", (byte)(3+j*2), iv[j]);
-      }
     }
   }
+
+  private void validateFiles(Path p1, Path p2, int len) throws Exception {
+    FSDataInputStream in1 = fs.open(p1);
+    FSDataInputStream in2 = fs.open(p2);
+    for (int i=0; i<len; i++) {
+      assertEquals("Mismatch at byte " + i, in1.read(), in2.read());
+    }
+    in1.close();
+    in2.close();
+  }
+
+  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, null);
+    final Path encFile1 = new Path(zone, "myfile");
+    DFSTestUtil.createFile(fs, encFile1, len, (short) 1, 0xFEED);
+    // Read them back in and compare byte-by-byte
+    validateFiles(baseFile, encFile1, len);
+    // Roll the key of the encryption zone
+    List<EncryptionZone> zones = dfsAdmin.listEncryptionZones();
+    assertEquals("Expected 1 EZ", 1, zones.size());
+    String keyId = zones.get(0).getKeyId();
+    cluster.getNamesystem().getProvider().rollNewVersion(keyId);
+    cluster.getNamesystem().getFSDirectory().ezManager.kickMonitor();
+    // Read them back in and compare byte-by-byte
+    validateFiles(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
+    validateFiles(encFile1, encFile2, len);
+  }
 }