/****************************************************************************
* Copyright (C) 2012 HS Coburg.
* All rights reserved.
* Contact: ecsec GmbH (info@ecsec.de)
*
* This file is part of the Open eCard App.
*
* GNU General Public License Usage
* This file may be used under the terms of the GNU General Public
* License version 3.0 as published by the Free Software Foundation
* and appearing in the file LICENSE.GPL included in the packaging of
* this file. Please review the following information to ensure the
* GNU General Public License version 3.0 requirements will be met:
* http://www.gnu.org/copyleft/gpl.html.
*
* Other Usage
* Alternatively, this file may be used in accordance with the terms
* and conditions contained in a signed written agreement between
* you and ecsec GmbH.
*
***************************************************************************/
package org.openecard.sal.protocol.genericcryptography;
import iso.std.iso_iec._24727.tech.schema.ConnectionHandleType;
import iso.std.iso_iec._24727.tech.schema.CryptographicServiceActionName;
import iso.std.iso_iec._24727.tech.schema.DIDScopeType;
import iso.std.iso_iec._24727.tech.schema.DIDStructureType;
import iso.std.iso_iec._24727.tech.schema.Decipher;
import iso.std.iso_iec._24727.tech.schema.DecipherResponse;
import java.io.ByteArrayOutputStream;
import java.math.BigInteger;
import java.util.Map;
import org.openecard.addon.sal.FunctionType;
import org.openecard.addon.sal.ProtocolStep;
import org.openecard.common.ECardConstants;
import org.openecard.common.ECardException;
import org.openecard.common.WSHelper;
import org.openecard.common.apdu.ManageSecurityEnvironment;
import org.openecard.common.apdu.common.CardCommandAPDU;
import org.openecard.common.apdu.common.CardResponseAPDU;
import org.openecard.common.interfaces.Dispatcher;
import org.openecard.common.sal.Assert;
import org.openecard.common.sal.anytype.CryptoMarkerType;
import org.openecard.common.sal.state.CardStateEntry;
import org.openecard.common.sal.util.SALUtils;
import org.openecard.common.tlv.TLV;
import org.openecard.common.util.ByteUtils;
import org.openecard.sal.protocol.genericcryptography.apdu.PSODecipher;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Implements the Decipher step of the Generic cryptography protocol.
* See TR-03112, version 1.1.2, part 7, section 4.9.6.
*
* @author Dirk Petrautzki <petrautzki@hs-coburg.de>
*/
public class DecipherStep implements ProtocolStep<Decipher, DecipherResponse> {
private static final Logger logger = LoggerFactory.getLogger(DecipherStep.class);
private static final byte PADDING_INDICATOR_BYTE = (byte) 0x00;
private final Dispatcher dispatcher;
/**
* Creates a new DecipherStep.
*
* @param dispatcher Dispatcher
*/
public DecipherStep(Dispatcher dispatcher) {
this.dispatcher = dispatcher;
}
@Override
public FunctionType getFunctionType() {
return FunctionType.Decipher;
}
@Override
public DecipherResponse perform(Decipher request, Map<String, Object> internalData) {
DecipherResponse response = WSHelper.makeResponse(DecipherResponse.class, WSHelper.makeResultOK());
try {
ConnectionHandleType connectionHandle = SALUtils.getConnectionHandle(request);
String didName = SALUtils.getDIDName(request);
byte[] applicationID = connectionHandle.getCardApplication();
CardStateEntry cardStateEntry = SALUtils.getCardStateEntry(internalData, connectionHandle);
Assert.securityConditionDID(cardStateEntry, applicationID, didName, CryptographicServiceActionName.DECIPHER);
DIDStructureType didStructure = SALUtils.getDIDStructure(request, didName, cardStateEntry, connectionHandle);
CryptoMarkerType cryptoMarker = new CryptoMarkerType(didStructure.getDIDMarker());
byte[] keyReference = cryptoMarker.getCryptoKeyInfo().getKeyRef().getKeyRef();
byte[] algorithmIdentifier = cryptoMarker.getAlgorithmInfo().getCardAlgRef();
byte[] slotHandle = connectionHandle.getSlotHandle();
// TODO eGK specific requirement
// See eGK specification, part 1, version 2.2.0, section 15.9.6.
if (didStructure.getDIDScope().equals(DIDScopeType.LOCAL)) {
keyReference[0] = (byte) (0x80 | keyReference[0]);
}
TLV tagKeyReference = new TLV();
tagKeyReference.setTagNumWithClass(0x84);
tagKeyReference.setValue(keyReference);
TLV tagAlgorithmIdentifier = new TLV();
tagAlgorithmIdentifier.setTagNumWithClass(0x80);
tagAlgorithmIdentifier.setValue(algorithmIdentifier);
byte[] mseData = ByteUtils.concatenate(tagKeyReference.toBER(), tagAlgorithmIdentifier.toBER());
CardCommandAPDU apdu = new ManageSecurityEnvironment((byte) 0x41, ManageSecurityEnvironment.CT, mseData);
apdu.transmit(dispatcher, slotHandle);
byte[] ciphertext = request.getCipherText();
ByteArrayOutputStream baos = new ByteArrayOutputStream();
BigInteger bitKeySize = cryptoMarker.getCryptoKeyInfo().getKeySize();
int blocksize = bitKeySize.divide(new BigInteger("8")).intValue();
// check if the ciphertext length is divisible by the blocksize without rest
if ((ciphertext.length % blocksize) != 0) {
return WSHelper.makeResponse(DecipherResponse.class, WSHelper.makeResultError(
ECardConstants.Minor.App.INCORRECT_PARM,
"The length of the ciphertext should be a multiple of the blocksize."));
}
// decrypt the ciphertext block for block
for (int offset = 0; offset < ciphertext.length; offset += blocksize) {
byte[] ciphertextblock = ByteUtils.copy(ciphertext, offset, blocksize);
apdu = new PSODecipher(ByteUtils.concatenate(PADDING_INDICATOR_BYTE, ciphertextblock), (byte) blocksize);
CardResponseAPDU responseAPDU = apdu.transmit(dispatcher, slotHandle);
baos.write(responseAPDU.getData());
}
response.setPlainText(baos.toByteArray());
} catch (ECardException e) {
response.setResult(e.getResult());
} catch (Exception e) {
logger.error(e.getMessage(), e);
response.setResult(WSHelper.makeResult(e));
}
return response;
}
}