public int processBlock(byte[] in, int inOff, byte[] out, int outOff)
throws DataLengthException, IllegalStateException {
cipher.processBlock(counter, 0, counterOut, 0);
//
// XOR the counterOut with the plaintext producing the cipher text
//
for (int i = 0; i < counterOut.length; i++) {
out[outOff + i] = (byte) (counterOut[i] ^ in[inOff + i]);
}
int carry = 1;
for (int i = counter.length - 1; i >= 0; i--) {
int x = (counter[i] & 0xff) + carry;
if (x > 0xff) {
carry = 1;
} else {
carry = 0;
}
counter[i] = (byte) x;
}
return counter.length;
}
/**
* Basic constructor.
*
* @param c the block cipher to be used.
*/
public SICBlockCipher(BlockCipher c) {
this.cipher = c;
this.blockSize = cipher.getBlockSize();
this.IV = new byte[blockSize];
this.counter = new byte[blockSize];
this.counterOut = new byte[blockSize];
}
public void init(
boolean forEncryption, // ignored by this CTR mode
CipherParameters params)
throws IllegalArgumentException {
if (params instanceof ParametersWithIV) {
ParametersWithIV ivParam = (ParametersWithIV) params;
byte[] iv = ivParam.getIV();
System.arraycopy(iv, 0, IV, 0, IV.length);
reset();
cipher.init(true, ivParam.getParameters());
} else {
throw new IllegalArgumentException("SIC mode requires ParametersWithIV");
}
}
/** Copy constructor. This will copy the state of the provided message digest. */
public GOST3411Digest(GOST3411Digest t) {
cipher.init(true, new ParametersWithSBox(null, GOST28147Engine.getSBox("D-A")));
reset();
System.arraycopy(t.H, 0, this.H, 0, t.H.length);
System.arraycopy(t.L, 0, this.L, 0, t.L.length);
System.arraycopy(t.M, 0, this.M, 0, t.M.length);
System.arraycopy(t.Sum, 0, this.Sum, 0, t.Sum.length);
System.arraycopy(t.C[1], 0, this.C[1], 0, t.C[1].length);
System.arraycopy(t.C[2], 0, this.C[2], 0, t.C[2].length);
System.arraycopy(t.C[3], 0, this.C[3], 0, t.C[3].length);
System.arraycopy(t.xBuf, 0, this.xBuf, 0, t.xBuf.length);
this.xBufOff = t.xBufOff;
this.byteCount = t.byteCount;
}
public void reset() {
System.arraycopy(IV, 0, counter, 0, counter.length);
cipher.reset();
}
public int getBlockSize() {
return cipher.getBlockSize();
}
public String getAlgorithmName() {
return cipher.getAlgorithmName() + "/SIC";
}
/** Standard constructor */
public GOST3411Digest() {
cipher.init(true, new ParametersWithSBox(null, GOST28147Engine.getSBox("D-A")));
reset();
}
// Encrypt function, ECB mode
private void E(byte[] key, byte[] s, int sOff, byte[] in, int inOff) {
cipher.init(true, new KeyParameter(key));
cipher.processBlock(in, inOff, s, sOff);
}
