/*
* Copyright (C) 2016 Nikita Mikhailov <nikita.s.mikhailov@gmail.com>
*
* 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 android.support.annotation.NonNull;
import org.sufficientlysecure.keychain.securitytoken.usb.UsbTransportException;
public class RBlock extends Block {
public static final byte MASK_RBLOCK = (byte) 0b11000000;
public static final byte MASK_VALUE_RBLOCK = (byte) 0b10000000;
private static final byte BIT_SEQUENCE = 4;
public RBlock(Block baseBlock) throws UsbTransportException {
super(baseBlock);
if (getApdu().length != 0) {
throw new UsbTransportException("Data in R-block");
}
}
public RBlock(BlockChecksumType checksumType, byte nad, byte sequence)
throws UsbTransportException {
super(checksumType, nad, (byte) (MASK_VALUE_RBLOCK | ((sequence & 1) << BIT_SEQUENCE)), new byte[0]);
}
public RError getError() throws UsbTransportException {
return RError.from(getPcb());
}
public enum RError {
NO_ERROR(0), EDC_ERROR(1), OTHER_ERROR(2);
private byte mLowBits;
RError(int lowBits) {
mLowBits = (byte) lowBits;
}
@NonNull
public static RError from(byte i) throws UsbTransportException {
for (final RError error : values()) {
if (error.mLowBits == (i & 0x3)) {
return error;
}
}
throw new UsbTransportException("Invalid R block error bits");
}
}
}