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     */
018    
019    package org.apache.hadoop.crypto.key;
020    
021    import java.io.IOException;
022    import java.net.URI;
023    import java.util.ArrayList;
024    import java.util.Date;
025    import java.util.HashMap;
026    import java.util.List;
027    import java.util.Map;
028    
029    import org.apache.hadoop.classification.InterfaceAudience;
030    import org.apache.hadoop.conf.Configuration;
031    import org.apache.hadoop.io.Text;
032    import org.apache.hadoop.security.Credentials;
033    import org.apache.hadoop.security.UserGroupInformation;
034    
035    /**
036     * A KeyProvider factory for UGIs. It uses the credentials object associated
037     * with the current user to find keys. This provider is created using a
038     * URI of "user:///".
039     */
040    @InterfaceAudience.Private
041    public class UserProvider extends KeyProvider {
042      public static final String SCHEME_NAME = "user";
043      private final UserGroupInformation user;
044      private final Credentials credentials;
045      private final Map<String, Metadata> cache = new HashMap<String, Metadata>();
046    
047      private UserProvider(Configuration conf) throws IOException {
048        super(conf);
049        user = UserGroupInformation.getCurrentUser();
050        credentials = user.getCredentials();
051      }
052    
053      @Override
054      public boolean isTransient() {
055        return true;
056      }
057    
058      @Override
059      public synchronized KeyVersion getKeyVersion(String versionName)
060          throws IOException {
061        byte[] bytes = credentials.getSecretKey(new Text(versionName));
062        if (bytes == null) {
063          return null;
064        }
065        return new KeyVersion(getBaseName(versionName), versionName, bytes);
066      }
067    
068      @Override
069      public synchronized Metadata getMetadata(String name) throws IOException {
070        if (cache.containsKey(name)) {
071          return cache.get(name);
072        }
073        byte[] serialized = credentials.getSecretKey(new Text(name));
074        if (serialized == null) {
075          return null;
076        }
077        Metadata result = new Metadata(serialized);
078        cache.put(name, result);
079        return result;
080      }
081    
082      @Override
083      public synchronized KeyVersion createKey(String name, byte[] material,
084                                   Options options) throws IOException {
085        Text nameT = new Text(name);
086        if (credentials.getSecretKey(nameT) != null) {
087          throw new IOException("Key " + name + " already exists in " + this);
088        }
089        if (options.getBitLength() != 8 * material.length) {
090          throw new IOException("Wrong key length. Required " +
091              options.getBitLength() + ", but got " + (8 * material.length));
092        }
093        Metadata meta = new Metadata(options.getCipher(), options.getBitLength(),
094            options.getDescription(), options.getAttributes(), new Date(), 1);
095        cache.put(name, meta);
096        String versionName = buildVersionName(name, 0);
097        credentials.addSecretKey(nameT, meta.serialize());
098        credentials.addSecretKey(new Text(versionName), material);
099        return new KeyVersion(name, versionName, material);
100      }
101    
102      @Override
103      public synchronized void deleteKey(String name) throws IOException {
104        Metadata meta = getMetadata(name);
105        if (meta == null) {
106          throw new IOException("Key " + name + " does not exist in " + this);
107        }
108        for(int v=0; v < meta.getVersions(); ++v) {
109          credentials.removeSecretKey(new Text(buildVersionName(name, v)));
110        }
111        credentials.removeSecretKey(new Text(name));
112        cache.remove(name);
113      }
114    
115      @Override
116      public synchronized KeyVersion rollNewVersion(String name,
117                                        byte[] material) throws IOException {
118        Metadata meta = getMetadata(name);
119        if (meta == null) {
120          throw new IOException("Key " + name + " not found");
121        }
122        if (meta.getBitLength() != 8 * material.length) {
123          throw new IOException("Wrong key length. Required " +
124              meta.getBitLength() + ", but got " + (8 * material.length));
125        }
126        int nextVersion = meta.addVersion();
127        credentials.addSecretKey(new Text(name), meta.serialize());
128        String versionName = buildVersionName(name, nextVersion);
129        credentials.addSecretKey(new Text(versionName), material);
130        return new KeyVersion(name, versionName, material);
131      }
132    
133      @Override
134      public String toString() {
135        return SCHEME_NAME + ":///";
136      }
137    
138      @Override
139      public synchronized void flush() {
140        user.addCredentials(credentials);
141      }
142    
143      public static class Factory extends KeyProviderFactory {
144    
145        @Override
146        public KeyProvider createProvider(URI providerName,
147                                          Configuration conf) throws IOException {
148          if (SCHEME_NAME.equals(providerName.getScheme())) {
149            return new UserProvider(conf);
150          }
151          return null;
152        }
153      }
154    
155      @Override
156      public synchronized List<String> getKeys() throws IOException {
157        List<String> list = new ArrayList<String>();
158        List<Text> keys = credentials.getAllSecretKeys();
159        for (Text key : keys) {
160          if (key.find("@") == -1) {
161            list.add(key.toString());
162          }
163        }
164        return list;
165      }
166    
167      @Override
168      public synchronized List<KeyVersion> getKeyVersions(String name) throws IOException {
169          List<KeyVersion> list = new ArrayList<KeyVersion>();
170          Metadata km = getMetadata(name);
171          if (km != null) {
172            int latestVersion = km.getVersions();
173            for (int i = 0; i < latestVersion; i++) {
174              KeyVersion v = getKeyVersion(buildVersionName(name, i));
175              if (v != null) {
176                list.add(v);
177              }
178            }
179          }
180          return list;
181      }
182    }