public byte [] Decrypt(byte [] cipher)
{
//int iters = cipher.Length / 8;
int blockSize = 8;
int rem = cipher.Length % blockSize;
if (rem != 0)
{
throw new Exception("must be in 8 byte blocks");
}
byte [] lastBlock = new byte[blockSize];
Array.Copy(cipher, cipher.Length - blockSize, lastBlock, 0, blockSize);
TripleDESCryptoServiceProvider tempTdcsp = new TripleDESCryptoServiceProvider();
tempTdcsp.Key = (byte[])_tdcsp.Key.Clone();
tempTdcsp.IV = lastBlock;
//TODO make this support other lengths 0x01 - 0x07070707070707
byte [] pkcs5 = new byte [] { 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08 };
byte [] padPlus = tempTdcsp.EncryptValue(pkcs5);
byte [] paddedCipher = new byte [cipher.Length + blockSize];
Array.Copy(cipher, 0, paddedCipher, 0, cipher.Length);
Array.Copy(padPlus, 0, paddedCipher, cipher.Length, blockSize);
byte [] plain = _tdcsp.DecryptValue(paddedCipher);
return(plain);
}
