if (params == null)
{
throw new IllegalStateException("CCM cipher unitialized.");
}
BlockCipher ctrCipher = new SICBlockCipher(cipher);
byte[] iv = new byte[blockSize];
byte[] nonce = params.getNonce();
int macSize = params.getMacSize() / 8;
byte[] out;
iv[0] = (byte)(((15 - nonce.length) - 1) & 0x7);
System.arraycopy(nonce, 0, iv, 1, nonce.length);
ctrCipher.init(forEncryption, new ParametersWithIV(params.getKey(), iv));
if (forEncryption)
{
int index = inOff;
int outOff = 0;
out = new byte[inLen + macSize];
calculateMac(in, inOff, inLen, macBlock);
ctrCipher.processBlock(macBlock, 0, macBlock, 0); // S0
while (index < inLen - blockSize) // S1...
{
ctrCipher.processBlock(in, index, out, outOff);
outOff += blockSize;
index += blockSize;
}
byte[] block = new byte[blockSize];
System.arraycopy(in, index, block, 0, inLen - index);
ctrCipher.processBlock(block, 0, block, 0);
System.arraycopy(block, 0, out, outOff, inLen - index);
outOff += inLen - index;
System.arraycopy(macBlock, 0, out, outOff, out.length - outOff);
}
else
{
int index = inOff;
int outOff = 0;
out = new byte[inLen - macSize];
System.arraycopy(in, inOff + inLen - macSize, macBlock, 0, macSize);
ctrCipher.processBlock(macBlock, 0, macBlock, 0);
for (int i = macSize; i != macBlock.length; i++)
{
macBlock[i] = 0;
}
while (outOff < out.length - blockSize)
{
ctrCipher.processBlock(in, index, out, outOff);
outOff += blockSize;
index += blockSize;
}
byte[] block = new byte[blockSize];
System.arraycopy(in, index, block, 0, out.length - outOff);
ctrCipher.processBlock(block, 0, block, 0);
System.arraycopy(block, 0, out, outOff, out.length - outOff);
byte[] calculatedMacBlock = new byte[blockSize];