View Javadoc

1   /*
2    *  Licensed to the Apache Software Foundation (ASF) under one
3    *  or more contributor license agreements.  See the NOTICE file
4    *  distributed with this work for additional information
5    *  regarding copyright ownership.  The ASF licenses this file
6    *  to you under the Apache License, Version 2.0 (the
7    *  "License"); you may not use this file except in compliance
8    *  with the License.  You may obtain a copy of the License at
9    *  
10   *    http://www.apache.org/licenses/LICENSE-2.0
11   *  
12   *  Unless required by applicable law or agreed to in writing,
13   *  software distributed under the License is distributed on an
14   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   *  KIND, either express or implied.  See the License for the
16   *  specific language governing permissions and limitations
17   *  under the License. 
18   *  
19   */
20  package org.apache.directory.server.kerberos.shared.io.decoder;
21  
22  
23  import java.io.IOException;
24  import java.util.Enumeration;
25  
26  import org.apache.directory.server.kerberos.shared.messages.application.ApplicationReply;
27  import org.apache.directory.shared.asn1.der.ASN1InputStream;
28  import org.apache.directory.shared.asn1.der.DERApplicationSpecific;
29  import org.apache.directory.shared.asn1.der.DEREncodable;
30  import org.apache.directory.shared.asn1.der.DERSequence;
31  import org.apache.directory.shared.asn1.der.DERTaggedObject;
32  
33  
34  /**
35   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
36   * @version $Rev: 540371 $, $Date: 2007-05-21 17:00:43 -0700 (Mon, 21 May 2007) $
37   */
38  public class ApplicationReplyDecoder
39  {
40      /**
41       * Decodes a byte array into an {@link ApplicationReply}.
42       *
43       * @param encodedAuthHeader
44       * @return The {@link ApplicationReply}.
45       * @throws IOException
46       */
47      public ApplicationReply decode( byte[] encodedAuthHeader ) throws IOException
48      {
49          ASN1InputStream ais = new ASN1InputStream( encodedAuthHeader );
50  
51          DERApplicationSpecific app = ( DERApplicationSpecific ) ais.readObject();
52  
53          DERSequence apreq = ( DERSequence ) app.getObject();
54  
55          return decodeApplicationRequestSequence( apreq );
56      }
57  
58  
59      /*
60       AP-REP ::=         [APPLICATION 15] SEQUENCE {
61       pvno[0]                   INTEGER,
62       msg-type[1]               INTEGER,
63       enc-part[2]               EncryptedData
64       }
65       */
66      private ApplicationReply decodeApplicationRequestSequence( DERSequence sequence )
67      {
68          ApplicationReply authHeader = null;
69  
70          for ( Enumeration e = sequence.getObjects(); e.hasMoreElements(); )
71          {
72              DERTaggedObject object = ( ( DERTaggedObject ) e.nextElement() );
73              int tag = object.getTagNo();
74              DEREncodable derObject = object.getObject();
75  
76              switch ( tag )
77              {
78                  case 0:
79                      //DERInteger tag0 = ( DERInteger ) derObject;
80                      //authHeader.setProtocolVersionNumber( tag0.intValue() );
81                      break;
82                  case 1:
83                      //DERInteger tag1 = ( DERInteger ) derObject;
84                      //authHeader.setMessageType( MessageType.getTypeByOrdinal( tag1.intValue() ) );
85                      break;
86                  case 2:
87                      DERSequence tag2 = ( DERSequence ) derObject;
88                      authHeader = new ApplicationReply( EncryptedDataDecoder.decode( tag2 ) );
89                      break;
90              }
91          }
92  
93          return authHeader;
94      }
95  }