private void F(int currentBlock)
{
// First iteration:
// Populate initial salt with the current block index:
Buffer.BlockCopy(
BlockNumberToBytes(currentBlock), 0,
saltAndBlockNumber, salt.Length, 4
);
buffer = prf.Transform(saltAndBlockNumber);
// Remaining iterations:
byte[] result = buffer;
for (long iteration = 2; iteration <= iterationCount; iteration++)
{
// Note that the PRF transform takes the immediate result of the
// last iteration, not the combined result (in buffer):
result = prf.Transform(result);
for (int byteIndex = 0; byteIndex < buffer.Length; byteIndex++)
{
buffer[byteIndex] ^= result[byteIndex];
}
}
}
