TLSharp.Core.MTProto.Crypto.AesEngine.GenerateWorkingKey C# (CSharp) Method

        private uint[,] GenerateWorkingKey(
            byte[] key,
            bool forEncryption)
        {
            int KC = key.Length / 4; // key length in words
            int t;

            if ((KC != 4) && (KC != 6) && (KC != 8))
                throw new ArgumentException("Key length not 128/192/256 bits.");

            ROUNDS = KC + 6; // This is not always true for the generalized Rijndael that allows larger block sizes
            var W = new uint[ROUNDS + 1, 4]; // 4 words in a block

            //
            // copy the key into the round key array
            //

            t = 0;
            for (int i = 0; i < key.Length; t++)
            {
                W[t >> 2, t & 3] = Pack.LE_To_UInt32(key, i);
                i += 4;
            }

            //
            // while not enough round key material calculated
            // calculate new values
            //
            int k = (ROUNDS + 1) << 2;
            for (int i = KC; (i < k); i++)
            {
                uint temp = W[(i - 1) >> 2, (i - 1) & 3];
                if ((i % KC) == 0)
                {
                    temp = SubWord(Shift(temp, 8)) ^ rcon[(i / KC) - 1];
                }
                else if ((KC > 6) && ((i % KC) == 4))
                {
                    temp = SubWord(temp);
                }

                W[i >> 2, i & 3] = W[(i - KC) >> 2, (i - KC) & 3] ^ temp;
            }

            if (!forEncryption)
            {
                for (int j = 1; j < ROUNDS; j++)
                {
                    for (int i = 0; i < 4; i++)
                    {
                        W[j, i] = Inv_Mcol(W[j, i]);
                    }
                }
            }

            return W;
        }