private static SafeAlgorithmHandle OpenRC2Algorithm(string cipherMode, int effectiveKeyLength)
{
SafeAlgorithmHandle hAlg = Cng.BCryptOpenAlgorithmProvider(Cng.BCRYPT_RC2_ALGORITHM, null, Cng.OpenAlgorithmProviderFlags.NONE);
hAlg.SetCipherMode(cipherMode);
if (effectiveKeyLength != 0)
{
Cng.SetEffectiveKeyLength(hAlg, effectiveKeyLength);
}
return(hAlg);
}
private byte[] _currentIv; // CNG mutates this with the updated IV for the next stage on each Encrypt/Decrypt call.
// The base IV holds a copy of the original IV for Reset(), until it is cleared by Dispose().
public BasicSymmetricCipherBCrypt(SafeAlgorithmHandle algorithm, CipherMode cipherMode, int blockSizeInBytes, byte[] key, int effectiveKeyLength, byte[] iv, bool encrypting)
: base(cipherMode.GetCipherIv(iv), blockSizeInBytes)
{
Debug.Assert(algorithm != null);
_encrypting = encrypting;
if (IV != null)
{
_currentIv = new byte[IV.Length];
}
_hKey = algorithm.BCryptImportKey(key);
if (effectiveKeyLength != 0)
{
Cng.SetEffectiveKeyLength(_hKey, effectiveKeyLength);
}
Reset();
}