internal void Update(UInt64[] message, Tweak tweak)
{
//
// Takes encoded tweak value and message, encrypts using current state as key and XORs
// result with message. The block size is determined by looking at input message length
// TODO: Reuse block cipher instance
//
if (_Hi.Length != message.Length){
throw new InvalidOperationException("Can't change block size in mid flight");
}
Threefish threeFish = new Threefish(_Hi, tweak, _blockSize);
threeFish.Encrypt(message, _Hi);
for (int i = 0; i < _Hi.Length; i++){
_Hi[i] ^= message[i];
}
}
static bool ThreefishTest(string hexKey, string hexTweak, string hexMessage, string hexExpectedCipherText, Threefish.ThreeFishBlockSize blockSize)
{
UInt64[] plainText = Util.ConvertLSBFirstToUInt64(Util.ByteArrayfromHex(hexMessage));
UInt64[] key = Util.ConvertLSBFirstToUInt64(Util.ByteArrayfromHex(hexKey));
UInt64[] tweak = Util.ConvertLSBFirstToUInt64(Util.ByteArrayfromHex(hexTweak));
UInt64[] cipherText = new UInt64[plainText.Length];
Threefish threefish = new Threefish(key, new Tweak { low64 = tweak[0], high64 = tweak[1] }, blockSize);
threefish.Encrypt(plainText, cipherText);
string hexObtainedCipherText = Util.HexStringFromByteArray(Util.ConvertUInt64ToLSBFirst(cipherText));
if (String.Compare(hexObtainedCipherText.ToLower(), hexExpectedCipherText.ToLower(), true) != 0)
{
System.Diagnostics.Debugger.Break();
Console.WriteLine("\n\n!!!Test failed!!!");
Console.WriteLine(" \n Key: {0} \n Tweak: {1} \n Message: {2} \n ExpectedCipher: {3}\n GotCipher: {4}", hexKey, hexTweak, hexMessage, hexExpectedCipherText, hexObtainedCipherText);
return false;
}
return true;
}