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,
013     *  software distributed under the License is distributed on an
014     *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015     *  KIND, either express or implied.  See the License for the
016     *  specific language governing permissions and limitations
017     *  under the License. 
018     *  
019     */
020    package org.apache.directory.server.changepw.io;
021    
022    
023    import java.io.IOException;
024    import java.nio.ByteBuffer;
025    
026    import org.apache.directory.server.changepw.messages.ChangePasswordError;
027    import org.apache.directory.server.changepw.messages.ChangePasswordErrorModifier;
028    import org.apache.directory.server.kerberos.shared.io.decoder.ErrorMessageDecoder;
029    import org.apache.directory.server.kerberos.shared.messages.ErrorMessage;
030    
031    
032    /**
033     * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
034     * @version $Rev$, $Date$
035     */
036    public class ChangePasswordErrorDecoder
037    {
038        private static final int HEADER_LENGTH = 6;
039    
040    
041        /**
042         * Decodes a {@link ByteBuffer} into a {@link ChangePasswordError}.
043         *
044         * @param buf
045         * @return The {@link ChangePasswordError}.
046         * @throws IOException
047         */
048        public ChangePasswordError decode( ByteBuffer buf ) throws IOException
049        {
050            ChangePasswordErrorModifier modifier = new ChangePasswordErrorModifier();
051    
052            short messageLength = buf.getShort();
053    
054            modifier.setProtocolVersionNumber( buf.getShort() );
055    
056            // AP_REQ length will be 0 for error messages
057            buf.getShort(); // authHeader length
058    
059            int errorLength = messageLength - HEADER_LENGTH;
060    
061            byte[] errorBytes = new byte[errorLength];
062    
063            buf.get( errorBytes );
064            ByteBuffer errorBuffer = ByteBuffer.wrap( errorBytes );
065    
066            ErrorMessageDecoder errorDecoder = new ErrorMessageDecoder();
067            ErrorMessage errorMessage = errorDecoder.decode( errorBuffer );
068    
069            modifier.setErrorMessage( errorMessage );
070    
071            return modifier.getChangePasswordError();
072        }
073    }