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.components.Ticket;
027    import org.apache.directory.shared.asn1.der.ASN1InputStream;
028    import org.apache.directory.shared.asn1.der.DERApplicationSpecific;
029    import org.apache.directory.shared.asn1.der.DEREncodable;
030    import org.apache.directory.shared.asn1.der.DERGeneralString;
031    import org.apache.directory.shared.asn1.der.DERInteger;
032    import org.apache.directory.shared.asn1.der.DERSequence;
033    import org.apache.directory.shared.asn1.der.DERTaggedObject;
034    
035    
036    /**
037     * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
038     * @version $Rev: 589780 $, $Date: 2007-10-29 19:14:59 +0100 (Mon, 29 Oct 2007) $
039     */
040    public class TicketDecoder
041    {
042        /**
043         * Decodes a byte array into an {@link Ticket}.
044         *
045         * @param encodedTicket
046         * @return The {@link Ticket}.
047         * @throws IOException
048         */
049        public static Ticket decode( byte[] encodedTicket ) throws IOException
050        {
051            ASN1InputStream ais = new ASN1InputStream( encodedTicket );
052    
053            DERApplicationSpecific app = ( DERApplicationSpecific ) ais.readObject();
054    
055            return decode( app );
056        }
057    
058    
059        /**
060         * Decodes a {@link DERSequence} into an array of {@link Ticket}s.
061         *
062         * @param sequence
063         * @return The array of {@link Ticket}s.
064         * @throws IOException
065         */
066        public static Ticket[] decodeSequence( DERSequence sequence ) throws IOException
067        {
068            Ticket[] tickets = new Ticket[sequence.size()];
069    
070            int ii = 0;
071            for ( Enumeration<DEREncodable> e = sequence.getObjects(); e.hasMoreElements(); )
072            {
073                DERApplicationSpecific object = ( DERApplicationSpecific ) e.nextElement();
074                tickets[ii] = decode( object );
075            }
076    
077            return tickets;
078        }
079    
080    
081        /**
082         * Ticket ::=                    [APPLICATION 1] SEQUENCE {
083         *     tkt-vno[0]                   INTEGER,
084         *     realm[1]                     Realm,
085         *     sname[2]                     PrincipalName,
086         *     enc-part[3]                  EncryptedData
087         * }
088         */
089        protected static Ticket decode( DERApplicationSpecific app ) throws IOException
090        {
091            DERSequence sequence = ( DERSequence ) app.getObject();
092    
093            Ticket ticket = new Ticket();
094    
095            for ( Enumeration<DEREncodable> e = sequence.getObjects(); e.hasMoreElements(); )
096            {
097                DERTaggedObject object = ( DERTaggedObject ) e.nextElement();
098                int tag = object.getTagNo();
099                DEREncodable derObject = object.getObject();
100    
101                switch ( tag )
102                {
103                    case 0:
104                        DERInteger tag0 = ( DERInteger ) derObject;
105                        ticket.setTktVno( tag0.intValue() );
106                        break;
107                        
108                    case 1:
109                        DERGeneralString tag1 = ( DERGeneralString ) derObject;
110                        ticket.setRealm( tag1.getString() );
111                        break;
112                        
113                    case 2:
114                        DERSequence tag2 = ( DERSequence ) derObject;
115                        ticket.setSName( PrincipalNameDecoder.decode( tag2 ) );
116                        break;
117                        
118                    case 3:
119                        DERSequence tag3 = ( DERSequence ) derObject;
120                        ticket.setEncPart( EncryptedDataDecoder.decode( tag3 ) );
121                        break;
122                }
123            }
124    
125            return ticket;
126        }
127    }