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 }