void ComputeBlock(uint pos)
{
BitPacking.BEBytesFromUInt32(pos, _saltBuffer, _saltBuffer.Length - 4);
ComputeHmac(_saltBuffer, _digestT1);
Array.Copy(_digestT1, _digest, _digestT1.Length);
for (int i = 1; i < _iterations; i++)
{
ComputeHmac(_digestT1, _digestT1);
for (int j = 0; j < _digest.Length; j++)
{
_digest[j] ^= _digestT1[j];
}
}
Security.Clear(_digestT1);
}
static byte[] MFcrypt(byte[] P, byte[] S,
int cost, int blockSize, int parallel, int?maxThreads)
{
int MFLen = blockSize * 128;
if (maxThreads == null)
{
maxThreads = int.MaxValue;
}
if (!BitMath.IsPositivePowerOf2(cost))
{
throw Exceptions.ArgumentOutOfRange("cost", "Cost must be a positive power of 2.");
}
Check.Range("blockSize", blockSize, 1, int.MaxValue / 128);
Check.Range("parallel", parallel, 1, int.MaxValue / MFLen);
Check.Range("maxThreads", (int)maxThreads, 1, int.MaxValue);
#if !(USEBC || NETCORE)
byte[] B = Pbkdf2.ComputeDerivedKey(new HMACSHA256(P), S, 1, parallel * MFLen);
#else
var mac = new nStratis.BouncyCastle.crypto.macs.HMac(new nStratis.BouncyCastle.crypto.digests.Sha256Digest());
mac.Init(new nStratis.BouncyCastle.crypto.parameters.KeyParameter(P));
byte[] B = Pbkdf2.ComputeDerivedKey(mac, S, 1, parallel * MFLen);
#endif
uint[] B0 = new uint[B.Length / 4];
for (int i = 0; i < B0.Length; i++)
{
B0[i] = BitPacking.UInt32FromLEBytes(B, i * 4);
} // code is easier with uint[]
ThreadSMixCalls(B0, MFLen, cost, blockSize, parallel, (int)maxThreads);
for (int i = 0; i < B0.Length; i++)
{
BitPacking.LEBytesFromUInt32(B0[i], B, i * 4);
}
Security.Clear(B0);
return(B);
}