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    package org.apache.hadoop.security.token.delegation.web;
019    
020    import org.apache.hadoop.classification.InterfaceAudience;
021    import org.apache.hadoop.classification.InterfaceStability;
022    import org.apache.hadoop.security.UserGroupInformation;
023    import org.apache.hadoop.security.authentication.client.PseudoAuthenticator;
024    
025    import java.io.IOException;
026    
027    /**
028     * The <code>PseudoDelegationTokenAuthenticator</code> provides support for
029     * Hadoop's pseudo authentication mechanism that accepts
030     * the user name specified as a query string parameter and support for Hadoop
031     * Delegation Token operations.
032     * <p/>
033     * This mimics the model of Hadoop Simple authentication trusting the
034     * {@link UserGroupInformation#getCurrentUser()} value.
035     */
036    @InterfaceAudience.Public
037    @InterfaceStability.Evolving
038    public class PseudoDelegationTokenAuthenticator
039        extends DelegationTokenAuthenticator {
040    
041      public PseudoDelegationTokenAuthenticator() {
042        super(new PseudoAuthenticator() {
043          @Override
044          protected String getUserName() {
045            try {
046              return UserGroupInformation.getCurrentUser().getShortUserName();
047            } catch (IOException ex) {
048              throw new RuntimeException(ex);
049            }
050          }
051        });
052      }
053    
054    }