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.web;
019
020import java.io.IOException;
021
022import org.apache.hadoop.security.UserGroupInformation;
023import org.apache.hadoop.security.authentication.client.Authenticator;
024import org.apache.hadoop.security.authentication.client.KerberosAuthenticator;
025import org.apache.hadoop.security.authentication.client.PseudoAuthenticator;
026
027/**
028 * Use UserGroupInformation as a fallback authenticator
029 * if the server does not use Kerberos SPNEGO HTTP authentication.
030 */
031public class KerberosUgiAuthenticator extends KerberosAuthenticator {
032  @Override
033  protected Authenticator getFallBackAuthenticator() {
034    return new PseudoAuthenticator() {
035      @Override
036      protected String getUserName() {
037        try {
038          return UserGroupInformation.getLoginUser().getUserName();
039        } catch (IOException e) {
040          throw new SecurityException("Failed to obtain current username", e);
041        }
042      }
043    };
044  }
045}