Org.BouncyCastle.Crypto.Digests.Sha3Digest.KeccakInitializeRoundConstants C# (CSharp) Method

        private static ulong[] KeccakInitializeRoundConstants()
        {
            ulong[] keccakRoundConstants = new ulong[24];
            byte LFSRState = 0x01;

            for (int i = 0; i < 24; i++)
            {
                keccakRoundConstants[i] = 0;
                for (int j = 0; j < 7; j++)
                {
                    int bitPosition = (1 << j) - 1;

                    // LFSR86540

                    bool loBit = (LFSRState & 0x01) != 0;
                    if (loBit)
                    {
                        keccakRoundConstants[i] ^= 1UL << bitPosition;
                    }

                    bool hiBit = (LFSRState & 0x80) != 0;
                    LFSRState <<= 1;
                    if (hiBit)
                    {
                        LFSRState ^= 0x71;
                    }

                }
            }

            return keccakRoundConstants;
        }