001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hdfs;
019
020import java.io.IOException;
021import java.net.URI;
022import java.net.URISyntaxException;
023import java.util.concurrent.Callable;
024import java.util.concurrent.ExecutionException;
025import java.util.concurrent.TimeUnit;
026
027import org.apache.commons.logging.Log;
028import org.apache.commons.logging.LogFactory;
029import org.apache.hadoop.conf.Configuration;
030import org.apache.hadoop.crypto.key.KeyProvider;
031
032import com.google.common.annotations.VisibleForTesting;
033import com.google.common.cache.Cache;
034import com.google.common.cache.CacheBuilder;
035import com.google.common.cache.RemovalListener;
036import com.google.common.cache.RemovalNotification;
037
038public class KeyProviderCache {
039
040  public static final Log LOG = LogFactory.getLog(KeyProviderCache.class);
041
042  private final Cache<URI, KeyProvider> cache;
043
044  public KeyProviderCache(long expiryMs) {
045    cache = CacheBuilder.newBuilder()
046        .expireAfterAccess(expiryMs, TimeUnit.MILLISECONDS)
047        .removalListener(new RemovalListener<URI, KeyProvider>() {
048          @Override
049          public void onRemoval(
050              RemovalNotification<URI, KeyProvider> notification) {
051            try {
052              notification.getValue().close();
053            } catch (Throwable e) {
054              LOG.error(
055                  "Error closing KeyProvider with uri ["
056                      + notification.getKey() + "]", e);
057              ;
058            }
059          }
060        })
061        .build();
062  }
063
064  public KeyProvider get(final Configuration conf) {
065    URI kpURI = createKeyProviderURI(conf);
066    if (kpURI == null) {
067      return null;
068    }
069    try {
070      return cache.get(kpURI, new Callable<KeyProvider>() {
071        @Override
072        public KeyProvider call() throws Exception {
073          return DFSUtil.createKeyProvider(conf);
074        }
075      });
076    } catch (Exception e) {
077      LOG.error("Could not create KeyProvider for DFSClient !!", e.getCause());
078      return null;
079    }
080  }
081
082  private URI createKeyProviderURI(Configuration conf) {
083    final String providerUriStr =
084        conf.get(DFSConfigKeys.DFS_ENCRYPTION_KEY_PROVIDER_URI, null);
085    // No provider set in conf
086    if (providerUriStr == null) {
087      LOG.error("Could not find uri with key ["
088          + DFSConfigKeys.DFS_ENCRYPTION_KEY_PROVIDER_URI
089          + "] to create a keyProvider !!");
090      return null;
091    }
092    final URI providerUri;
093    try {
094      providerUri = new URI(providerUriStr);
095    } catch (URISyntaxException e) {
096      LOG.error("KeyProvider URI string is invalid [" + providerUriStr
097          + "]!!", e.getCause());
098      return null;
099    }
100    return providerUri;
101  }
102
103  @VisibleForTesting
104  public void setKeyProvider(Configuration conf, KeyProvider keyProvider)
105      throws IOException {
106    URI uri = createKeyProviderURI(conf);
107    cache.put(uri, keyProvider);
108  }
109}