protected override void Compress(ref SkeinState state, byte[] buffer, UInt64 bitCount)
{
var keyState = new UInt64[SKEIN_512_STATE_WORDS + 1];
var tweakState = new UInt64[3];
tweakState[0] = bitCount;
tweakState[1] = (UInt64)state.Flags;
keyState[0] = state.Hash[0];
keyState[1] = state.Hash[1];
keyState[2] = state.Hash[2];
keyState[3] = state.Hash[3];
keyState[4] = state.Hash[4];
keyState[5] = state.Hash[5];
keyState[6] = state.Hash[6];
keyState[7] = state.Hash[7];
keyState[8] = keyState[0] ^ keyState[1] ^ keyState[2] ^ keyState[3] ^
keyState[4] ^ keyState[5] ^ keyState[6] ^ keyState[7] ^ 0x5555555555555555;
tweakState[2] = tweakState[0] ^ tweakState[1];
var block = ToBlock(buffer);
var X = new UInt64[SKEIN_512_STATE_WORDS];
for (int i = 0; i < SKEIN_512_STATE_WORDS; i++)
{
X[i] = block[i];
}
X[0] = block[0] + keyState[0];
X[1] = block[1] + keyState[1];
X[2] = block[2] + keyState[2];
X[3] = block[3] + keyState[3];
X[4] = block[4] + keyState[4];
X[5] = block[5] + keyState[5] + tweakState[0];
X[6] = block[6] + keyState[6] + tweakState[1];
X[7] = block[7] + keyState[7];
// 72 round plus injects
EigthRounds(X, keyState, tweakState, 0);
EigthRounds(X, keyState, tweakState, 1);
EigthRounds(X, keyState, tweakState, 2);
EigthRounds(X, keyState, tweakState, 3);
EigthRounds(X, keyState, tweakState, 4);
EigthRounds(X, keyState, tweakState, 5);
EigthRounds(X, keyState, tweakState, 6);
EigthRounds(X, keyState, tweakState, 7);
EigthRounds(X, keyState, tweakState, 8);
state.Hash[0] = X[0] ^ block[0];
state.Hash[1] = X[1] ^ block[1];
state.Hash[2] = X[2] ^ block[2];
state.Hash[3] = X[3] ^ block[3];
state.Hash[4] = X[4] ^ block[4];
state.Hash[5] = X[5] ^ block[5];
state.Hash[6] = X[6] ^ block[6];
state.Hash[7] = X[7] ^ block[7];
state.Flags &= ~SkeinFlags.First; // Disable "First" flag
}
protected override byte[] FinalHash(SkeinState state)
{
var hashBytes = SKEIN_256_BLOCK_BYTES;
var lastBytes = 8;
if (this._bitLen == 224)
{
hashBytes -= 4;
lastBytes = 4;
}
var result = new byte[hashBytes];
int h;
for (h = 0; h < SKEIN_256_STATE_WORDS - 1; h++)
{
var completeBytes = BitConverter.GetBytes(state.Hash[h]);
Buffer.BlockCopy(completeBytes, 0, result, h << 3, 8);
}
var finalBytes = BitConverter.GetBytes(state.Hash[h]);
Buffer.BlockCopy(finalBytes, 0, result, h << 3, lastBytes);
return(result);
}
private SkeinState Init()
{
var result = new SkeinState();
result.Hash = new UInt64[this._stateWords];
for (int h = 0; h < this._stateWords; h++)
{
result.Hash[h] = this._initState[h];
}
result.Flags = SetType(BlockType.MSG);
return(result);
}
protected override byte[] FinalHash(SkeinState state)
{
var hashBytes = SKEIN_512_BLOCK_BYTES;
if (this._bitLen == 384)
{
hashBytes -= 16;
}
var result = new byte[hashBytes];
int hashCount = hashBytes / 8;
for (int h = 0; h < hashCount; h++)
{
var bytes = BitConverter.GetBytes(state.Hash[h]);
Buffer.BlockCopy(bytes, 0, result, h << 3, 8);
}
return(result);
}
protected abstract byte[] FinalHash(SkeinState state);
protected abstract void Compress(ref SkeinState State, byte[] buffer, UInt64 bitCount);
