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.EncryptedData; 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: 587682 $, $Date: 2007-10-24 00:47:43 +0200 (Wed, 24 Oct 2007) $ 039 */ 040 public class EncryptedDataDecoder 041 { 042 /** 043 * Decodes a byte array into an {@link EncryptedData}. 044 * 045 * @param encodedEncryptedData 046 * @return The {@link EncryptedData}. 047 * @throws IOException 048 */ 049 public static EncryptedData decode( byte[] encodedEncryptedData ) throws IOException 050 { 051 ASN1InputStream ais = new ASN1InputStream( encodedEncryptedData ); 052 053 DERSequence sequence = ( DERSequence ) ais.readObject(); 054 055 return decode( sequence ); 056 } 057 058 059 /** 060 * Decodes a {@link DERSequence} into an {@link EncryptedData}. 061 * 062 * EncryptedData ::= SEQUENCE { 063 * etype[0] INTEGER, -- EncryptionEngine 064 * kvno[1] INTEGER OPTIONAL, 065 * cipher[2] OCTET STRING -- ciphertext 066 * } 067 * 068 * @param sequence 069 * @return The {@link EncryptedData}. 070 */ 071 public static EncryptedData decode( DERSequence sequence ) 072 { 073 EncryptedData encryptedData = new EncryptedData(); 074 075 for ( Enumeration<DEREncodable> e = sequence.getObjects(); e.hasMoreElements(); ) 076 { 077 DERTaggedObject object = ( DERTaggedObject ) e.nextElement(); 078 int tag = object.getTagNo(); 079 DEREncodable derObject = object.getObject(); 080 081 switch ( tag ) 082 { 083 case 0: 084 DERInteger etype = ( DERInteger ) derObject; 085 encryptedData.setEType( EncryptionType.getTypeByOrdinal( etype.intValue() ) ); 086 break; 087 088 case 1: 089 DERInteger kvno = ( DERInteger ) derObject; 090 encryptedData.setKvno( kvno.intValue() ); 091 break; 092 093 case 2: 094 DEROctetString cipher = ( DEROctetString ) derObject; 095 encryptedData.setCipher( cipher.getOctets() ); 096 break; 097 } 098 } 099 100 return encryptedData; 101 } 102 }