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.crypto.encryption.EncryptionType;
027 import org.apache.directory.server.kerberos.shared.messages.value.EncryptionTypeInfoEntry;
028 import org.apache.directory.shared.asn1.der.ASN1InputStream;
029 import org.apache.directory.shared.asn1.der.DEREncodable;
030 import org.apache.directory.shared.asn1.der.DERInteger;
031 import org.apache.directory.shared.asn1.der.DEROctetString;
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: 540371 $, $Date: 2007-05-21 17:00:43 -0700 (Mon, 21 May 2007) $
039 */
040 public class EncryptionTypeInfoDecoder
041 {
042 /**
043 * Decodes a byte array into an array of {@link EncryptionTypeInfoEntry}.
044 *
045 * @param encodedEntries
046 * @return The array of {@link EncryptionTypeInfoEntry}.
047 * @throws IOException
048 */
049 public EncryptionTypeInfoEntry[] decode( byte[] encodedEntries ) throws IOException
050 {
051 ASN1InputStream ais = new ASN1InputStream( encodedEntries );
052
053 DERSequence sequence = ( DERSequence ) ais.readObject();
054
055 return decodeSequence( sequence );
056 }
057
058
059 /**
060 * ETYPE-INFO ::= SEQUENCE OF ETYPE-INFO-ENTRY
061 */
062 protected static EncryptionTypeInfoEntry[] decodeSequence( DERSequence sequence )
063 {
064 EncryptionTypeInfoEntry[] entrySequence = new EncryptionTypeInfoEntry[sequence.size()];
065
066 int ii = 0;
067 for ( Enumeration<DEREncodable> e = sequence.getObjects(); e.hasMoreElements(); )
068 {
069 DERSequence object = (DERSequence)e.nextElement();
070 entrySequence[ii] = decode( object );
071 ii++;
072 }
073
074 return entrySequence;
075 }
076
077
078 /**
079 * ETYPE-INFO-ENTRY ::= SEQUENCE {
080 * etype [0] Int32,
081 * salt [1] OCTET STRING OPTIONAL
082 * }
083 */
084 protected static EncryptionTypeInfoEntry decode( DERSequence sequence )
085 {
086 EncryptionType encryptionType = EncryptionType.NULL;
087 byte[] salt = new byte[0];
088
089 for ( Enumeration<DEREncodable> e = sequence.getObjects(); e.hasMoreElements(); )
090 {
091 DERTaggedObject object = (DERTaggedObject)e.nextElement();
092 int tag = object.getTagNo();
093 DEREncodable derObject = object.getObject();
094
095 switch ( tag )
096 {
097 case 0:
098 DERInteger type = ( DERInteger ) derObject;
099 encryptionType = EncryptionType.getTypeByOrdinal( type.intValue() );
100 break;
101 case 1:
102 DEROctetString value = ( DEROctetString ) derObject;
103 salt = value.getOctets();
104 break;
105 }
106 }
107
108 return new EncryptionTypeInfoEntry( encryptionType, salt );
109 }
110 }