/// <exception cref="ArgumentException">Wrong length of IV.</exception>
public ICryptoTransform Create(CryptoDirection direction, Mode mode, byte[] iv)
{
if (iv.Length != BlockSize)
{
throw new ArgumentException("Wrong length of IV.");
}
InitRoundKey(direction);
switch (mode)
{
default:
case Mode.ECB:
if (direction == CryptoDirection.Encrypt)
{
return(new FROGEncryptTransform(_encryptRoundKeys));
}
else
{
return(new FROGDecryptTransform(_decryptRoundKeys));
}
case Mode.CBC:
return(CBC.Get(CreateNice(direction), iv, direction));
case Mode.CFB:
return(CFB.Get(CreateNice(CryptoDirection.Encrypt), iv, direction));
case Mode.OFB:
return(OFB.Get(CreateNice(CryptoDirection.Encrypt), iv, direction));
}
}
private static byte[] TransformEmptyText(byte[][][] preliminaryKey, byte[] iv)
{
int blocksCount = 2304 / BlockSize;
byte[] buf = new byte[BlockSize];
byte[] result = new byte[2304];
ICryptoTransform transform = CBC.Get(new FROGEncryptTransform(preliminaryKey), iv, CryptoDirection.Encrypt);
for (int i = 0; i < blocksCount; i++)
{
Array.Fill <byte>(buf, 0);
transform.TransformBlock(buf, 0, BlockSize, result, i * BlockSize);
}
return(result);
}
/// <exception cref="ArgumentException">Wrong key length or IV length</exception>
public static ICryptoTransform Get(byte[] key, Size stateSize, byte[] IV, Mode mode, CryptoDirection direction)
{
switch (mode)
{
default:
case Mode.ECB:
return(Get(key, stateSize, direction));
case Mode.CBC:
return(CBC.Get(GetNice(key, stateSize, direction), IV, direction));
case Mode.CFB:
return(CFB.Get(GetNice(key, stateSize, CryptoDirection.Encrypt), IV, direction));
case Mode.OFB:
return(OFB.Get(GetNice(key, stateSize, CryptoDirection.Encrypt), IV, direction));
}
}