/* CryptoNight Step 2: Iteratively encrypt the results from Keccak
* to fill the large scratchpad
*/
public static byte[] FillScratchpad(CNState cnState, ICryptoNight cnParams)
{
/* Expand our initial key into many for each round of pseudo aes */
byte[] expandedKeys = AES.ExpandKey(cnState.GetAESKey(), cnParams.Intrinsics);
/* Our large scratchpad, 2MB in default CN */
byte[] scratchpad = new byte[cnParams.Memory];
byte[] text = cnState.GetText();
if (cnParams.Intrinsics && Aes.IsSupported && Sse2.IsSupported)
{
/* Fill the scratchpad with AES encryption of text */
for (int i = 0; i < cnParams.InitRounds; i++)
{
AES.AESPseudoRoundNative(expandedKeys, text);
/* Write text to the scratchpad, at the offset
* i * InitSizeByte */
Buffer.BlockCopy(text, 0, scratchpad, i * Constants.INIT_SIZE_BYTE, text.Length);
}
}
else
{
/* Fill the scratchpad with AES encryption of text */
for (int i = 0; i < cnParams.InitRounds; i++)
{
AES.AESPseudoRound(expandedKeys, text, cnParams.Intrinsics);
/* Write text to the scratchpad, at the offset
* i * InitSizeByte */
Buffer.BlockCopy(text, 0, scratchpad, i * Constants.INIT_SIZE_BYTE, text.Length);
}
}
return(scratchpad);
}