open-keychain/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/securitytoken/usb/tpdu/T1TpduBlockFactory.java
2017-12-15 16:03:36 +01:00

54 lines
2 KiB
Java

/*
* Copyright (C) 2017 Schürmann & Breitmoser GbR
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.sufficientlysecure.keychain.securitytoken.usb.tpdu;
import org.sufficientlysecure.keychain.securitytoken.usb.UsbTransportException;
class T1TpduBlockFactory {
private BlockChecksumAlgorithm checksumType;
T1TpduBlockFactory(BlockChecksumAlgorithm checksumType) {
this.checksumType = checksumType;
}
Block fromBytes(byte[] data) throws UsbTransportException {
byte pcbByte = data[Block.OFFSET_PCB];
if ((pcbByte & IBlock.MASK_IBLOCK) == IBlock.MASK_VALUE_IBLOCK) {
return new IBlock(checksumType, data);
} else if ((pcbByte & SBlock.MASK_SBLOCK) == SBlock.MASK_VALUE_SBLOCK) {
return new SBlock(checksumType, data);
} else if ((pcbByte & RBlock.MASK_RBLOCK) == RBlock.MASK_VALUE_RBLOCK) {
return new RBlock(checksumType, data);
}
throw new UsbTransportException("TPDU Unknown block type");
}
IBlock newIBlock(byte sequence, boolean chaining, byte[] apdu, int offset, int length)
throws UsbTransportException {
return new IBlock(checksumType, (byte) 0, sequence, chaining, apdu, offset, length);
}
RBlock createAckRBlock(byte receivedSeqNum) throws UsbTransportException {
return new RBlock(checksumType, (byte) 0, (byte) (receivedSeqNum + 1));
}
}