Class DSTU7624Mac

core/src/main/java/org/bouncycastle/crypto/macs/DSTU7624Mac.java:28–189

Implementation of DSTU7624 MAC mode. This is a CBC-MAC variant (a CBC chain whose final block is masked with kDelta = E(0) before the last encryption) and, like raw CBC-MAC, it is defined only for input that is a whole number of blocks: #doFinal rejects a trailing partial block with "inp

 * </p>
 */
public class DSTU7624Mac
    implements Mac
{
    private final static int BITS_IN_BYTE = 8;

    private byte[]              buf;
    private int                 bufOff;

    private int macSize;
    private int blockSize;
    private DSTU7624Engine engine;

    private byte[] c, cTemp, kDelta;

    private boolean initCalled = false;

    public DSTU7624Mac(int blockBitLength, int q)
    {
        this.engine = new DSTU7624Engine(blockBitLength);
        this.blockSize = blockBitLength / BITS_IN_BYTE;
        this.macSize = q / BITS_IN_BYTE;
        this.c = new byte[blockSize];
        this.kDelta = new byte[blockSize];
        this.cTemp = new byte[blockSize];
        this.buf = new byte[blockSize];
    }

    public void init(CipherParameters params)
        throws IllegalArgumentException
    {
        if (params instanceof KeyParameter)
        {
            engine.init(true, params);
            initCalled = true;
            reset();
        }
        else
        {
            throw new IllegalArgumentException("Invalid parameter passed to DSTU7624Mac");
        }
    }

    public String getAlgorithmName()
    {
        return "DSTU7624Mac";
    }

    public int getMacSize()
    {
        return macSize;
    }

    public void update(byte in)
    {
        if (bufOff == buf.length)
        {
            processBlock(buf, 0);
            bufOff = 0;