CSPspEmu.Core.Crypto.Crypto.rijndaelKeySetupDec C# (CSharp) Method

        public static int rijndaelKeySetupDec(uint *rk /*4*(Nr + 1)*/, byte* cipherKey, int keyBits)
        {
            int Nr, i, j;
            uint temp;

            /* expand the cipher key: */
            Nr = rijndaelKeySetupEnc(rk, cipherKey, keyBits);

            /* invert the order of the round keys: */
            for (i = 0, j = 4*Nr; i < j; i += 4, j -= 4) {
                temp = rk[i    ]; rk[i    ] = rk[j    ]; rk[j    ] = temp;
                temp = rk[i + 1]; rk[i + 1] = rk[j + 1]; rk[j + 1] = temp;
                temp = rk[i + 2]; rk[i + 2] = rk[j + 2]; rk[j + 2] = temp;
                temp = rk[i + 3]; rk[i + 3] = rk[j + 3]; rk[j + 3] = temp;
            }
            /* apply the inverse MixColumn transform to all round keys but the first and the last: */
            for (i = 1; i < Nr; i++) {
                rk += 4;
                rk[0] =
                    Td0[Te4[(rk[0] >> 24)       ] & 0xff] ^
                    Td1[Te4[(rk[0] >> 16) & 0xff] & 0xff] ^
                    Td2[Te4[(rk[0] >>  8) & 0xff] & 0xff] ^
                    Td3[Te4[(rk[0]      ) & 0xff] & 0xff];
                rk[1] =
                    Td0[Te4[(rk[1] >> 24)       ] & 0xff] ^
                    Td1[Te4[(rk[1] >> 16) & 0xff] & 0xff] ^
                    Td2[Te4[(rk[1] >>  8) & 0xff] & 0xff] ^
                    Td3[Te4[(rk[1]      ) & 0xff] & 0xff];
                rk[2] =
                    Td0[Te4[(rk[2] >> 24)       ] & 0xff] ^
                    Td1[Te4[(rk[2] >> 16) & 0xff] & 0xff] ^
                    Td2[Te4[(rk[2] >>  8) & 0xff] & 0xff] ^
                    Td3[Te4[(rk[2]      ) & 0xff] & 0xff];
                rk[3] =
                    Td0[Te4[(rk[3] >> 24)       ] & 0xff] ^
                    Td1[Te4[(rk[3] >> 16) & 0xff] & 0xff] ^
                    Td2[Te4[(rk[3] >>  8) & 0xff] & 0xff] ^
                    Td3[Te4[(rk[3]      ) & 0xff] & 0xff];
            }
            return Nr;
        }