/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*
*/
package org.apache.directory.server.kerberos.shared.io.decoder;
import java.io.IOException;
import java.util.Enumeration;
import org.apache.directory.server.kerberos.shared.crypto.encryption.EncryptionType;
import org.apache.directory.server.kerberos.shared.messages.value.EncryptedData;
import org.apache.directory.shared.asn1.der.ASN1InputStream;
import org.apache.directory.shared.asn1.der.DEREncodable;
import org.apache.directory.shared.asn1.der.DERInteger;
import org.apache.directory.shared.asn1.der.DEROctetString;
import org.apache.directory.shared.asn1.der.DERSequence;
import org.apache.directory.shared.asn1.der.DERTaggedObject;
/**
* @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
* @version $Rev: 587682 $, $Date: 2007-10-24 00:47:43 +0200 (Mer, 24 oct 2007) $
*/
public class EncryptedDataDecoder
{
/**
* Decodes a byte array into an {@link EncryptedData}.
*
* @param encodedEncryptedData
* @return The {@link EncryptedData}.
* @throws IOException
*/
public static EncryptedData decode( byte[] encodedEncryptedData ) throws IOException
{
ASN1InputStream ais = new ASN1InputStream( encodedEncryptedData );
DERSequence sequence = ( DERSequence ) ais.readObject();
return decode( sequence );
}
/**
* Decodes a {@link DERSequence} into an {@link EncryptedData}.
*
* EncryptedData ::= SEQUENCE {
* etype[0] INTEGER, -- EncryptionEngine
* kvno[1] INTEGER OPTIONAL,
* cipher[2] OCTET STRING -- ciphertext
* }
*
* @param sequence
* @return The {@link EncryptedData}.
*/
public static EncryptedData decode( DERSequence sequence )
{
EncryptedData encryptedData = new EncryptedData();
for ( Enumeration<DEREncodable> e = sequence.getObjects(); e.hasMoreElements(); )
{
DERTaggedObject object = ( DERTaggedObject ) e.nextElement();
int tag = object.getTagNo();
DEREncodable derObject = object.getObject();
switch ( tag )
{
case 0:
DERInteger etype = ( DERInteger ) derObject;
encryptedData.setEType( EncryptionType.getTypeByOrdinal( etype.intValue() ) );
break;
case 1:
DERInteger kvno = ( DERInteger ) derObject;
encryptedData.setKvno( kvno.intValue() );
break;
case 2:
DEROctetString cipher = ( DEROctetString ) derObject;
encryptedData.setCipher( cipher.getOctets() );
break;
}
}
return encryptedData;
}
}