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.kerberos.shared.io.decoder;
021
022
023 import java.io.IOException;
024 import java.util.Enumeration;
025
026 import org.apache.directory.server.kerberos.shared.messages.Encodable;
027 import org.apache.directory.server.kerberos.shared.messages.components.EncApRepPart;
028 import org.apache.directory.server.kerberos.shared.messages.components.EncApRepPartModifier;
029 import org.apache.directory.shared.asn1.der.ASN1InputStream;
030 import org.apache.directory.shared.asn1.der.DERApplicationSpecific;
031 import org.apache.directory.shared.asn1.der.DEREncodable;
032 import org.apache.directory.shared.asn1.der.DERGeneralizedTime;
033 import org.apache.directory.shared.asn1.der.DERInteger;
034 import org.apache.directory.shared.asn1.der.DERSequence;
035 import org.apache.directory.shared.asn1.der.DERTaggedObject;
036
037
038 /**
039 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
040 * @version $Rev: 502338 $, $Date: 2007-02-01 11:59:43 -0800 (Thu, 01 Feb 2007) $
041 */
042 public class EncApRepPartDecoder implements Decoder, DecoderFactory
043 {
044 public Decoder getDecoder()
045 {
046 return new EncApRepPartDecoder();
047 }
048
049
050 public Encodable decode( byte[] encodedEncApRepPart ) throws IOException
051 {
052 ASN1InputStream ais = new ASN1InputStream( encodedEncApRepPart );
053
054 DERApplicationSpecific app = ( DERApplicationSpecific ) ais.readObject();
055
056 DERSequence apRepPart = ( DERSequence ) app.getObject();
057
058 return decodeEncApRepPartSequence( apRepPart );
059 }
060
061
062 /**
063 * Decodes a {@link DERSequence} into a {@link EncApRepPart}.
064 *
065 * EncAPRepPart ::= [APPLICATION 27] SEQUENCE {
066 * ctime [0] KerberosTime,
067 * cusec [1] Microseconds,
068 * subkey [2] EncryptionKey OPTIONAL,
069 * seq-number [3] UInt32 OPTIONAL
070 * }
071 *
072 * @param sequence
073 * @return The {@link EncApRepPart}.
074 */
075 private EncApRepPart decodeEncApRepPartSequence( DERSequence sequence )
076 {
077 EncApRepPartModifier modifier = new EncApRepPartModifier();
078
079 for ( Enumeration e = sequence.getObjects(); e.hasMoreElements(); )
080 {
081 DERTaggedObject object = ( DERTaggedObject ) e.nextElement();
082 int tag = object.getTagNo();
083 DEREncodable derObject = object.getObject();
084
085 switch ( tag )
086 {
087 case 0:
088 DERGeneralizedTime tag0 = ( DERGeneralizedTime ) derObject;
089 modifier.setClientTime( KerberosTimeDecoder.decode( tag0 ) );
090 break;
091 case 1:
092 DERInteger tag1 = ( DERInteger ) derObject;
093 modifier.setClientMicroSecond( new Integer( tag1.intValue() ) );
094 break;
095 case 2:
096 DERSequence tag2 = ( DERSequence ) derObject;
097 modifier.setSubSessionKey( EncryptionKeyDecoder.decode( tag2 ) );
098 break;
099 case 3:
100 DERInteger tag3 = ( DERInteger ) derObject;
101 modifier.setSequenceNumber( new Integer( tag3.intValue() ) );
102 break;
103 }
104 }
105
106 return modifier.getEncApRepPart();
107 }
108 }