/// <summary>
/// Process the last block of data
/// </summary>
///
/// <param name="Output">The hash value return</param>
/// <param name="OutOffset">The offset in the data</param>
///
/// <returns>The number of bytes processed</returns>
///
/// <exception cref="CryptoMacException">Thrown if Output array is too small</exception>
public int DoFinal(byte[] Output, int OutOffset)
{
if (Output.Length - OutOffset < m_macSize)
{
throw new CryptoMacException("CMAC:DoFinal", "The Output buffer is too short!", new ArgumentOutOfRangeException());
}
if (m_wrkOffset != m_blockSize)
{
ISO7816 pad = new ISO7816();
pad.AddPadding(m_wrkBuffer, m_wrkOffset);
for (int i = 0; i < m_msgCode.Length; i++)
{
m_wrkBuffer[i] ^= m_K2[i];
}
}
else
{
for (int i = 0; i < m_msgCode.Length; i++)
{
m_wrkBuffer[i] ^= m_K1[i];
}
}
m_cipherMode.Transform(m_wrkBuffer, 0, m_msgCode, 0);
Buffer.BlockCopy(m_msgCode, 0, Output, OutOffset, m_macSize);
Reset();
return(m_macSize);
}
private void OfbModeTest()
{
AllocateRandom(ref _iv, 16);
AllocateRandom(ref _key, 32);
KeyParams kp = new KeyParams(_key, _iv);
RHX eng = new RHX();
OFB cipher = new OFB(eng);
OFB cipher2 = new OFB(eng);
ISO7816 padding = new ISO7816();
cipher.IsParallel = false;
CipherStream cs = new CipherStream(cipher2, padding);
for (int i = 0; i < 10; i++)
{
int sze = AllocateRandom(ref _plnText, 0, eng.BlockSize);
int prlBlock = sze - (sze % (cipher.BlockSize * _processorCount));
_cmpText = new byte[sze];
_decText = new byte[sze];
_encText = new byte[sze];
MemoryStream mIn = new MemoryStream(_plnText);
MemoryStream mOut = new MemoryStream();
MemoryStream mRes = new MemoryStream();
// *** Compare encryption output *** //
// local processor
cipher.Initialize(true, kp);
BlockEncrypt(cipher, padding, _plnText, 0, ref _encText, 0);
// streamcipher linear mode
cs.IsParallel = false;
// memorystream interface
cs.Initialize(true, kp);
cs.Write(mIn, mOut);
if (!Evaluate.AreEqual(mOut.ToArray(), _encText))
{
throw new Exception("CipherStreamTest: Encrypted arrays are not equal!");
}
// byte array interface
cs.Initialize(true, kp);
cs.Write(_plnText, 0, ref _cmpText, 0);
if (!Evaluate.AreEqual(_cmpText, _encText))
{
throw new Exception("CipherStreamTest: Encrypted arrays are not equal!");
}
// ***compare decryption output *** //
// local processor
cipher.Initialize(false, kp);
BlockDecrypt(cipher, padding, _encText, 0, ref _decText, 0);
if (!Evaluate.AreEqual(_plnText, _decText))
{
throw new Exception("CipherStreamTest: Decrypted arrays are not equal!");
}
// decrypt linear mode
cipher2.IsParallel = false;
mOut.Seek(0, SeekOrigin.Begin);
cs.Initialize(false, kp);
cs.Write(mOut, mRes);
if (!Evaluate.AreEqual(mRes.ToArray(), _decText))
{
throw new Exception("CipherStreamTest: Decrypted arrays are not equal!");
}
// byte array interface
cs.Initialize(false, kp);
Array.Resize(ref _cmpText, _encText.Length);
cs.Write(_encText, 0, ref _cmpText, 0);
if (!Evaluate.AreEqual(_cmpText, _decText))
{
throw new Exception("CipherStreamTest: Decrypted arrays are not equal!");
}
}
eng.Dispose();
}