WaterFlush/Packages/com.tivadar.best.http/Runtime/Shared/TLS/Crypto/Impl/FastAesEngine.cs

#if !BESTHTTP_DISABLE_ALTERNATE_SSL && (!UNITY_WEBGL || UNITY_EDITOR)
#pragma warning disable
using System;
using System.Diagnostics;

using Best.HTTP.SecureProtocol.Org.BouncyCastle.Crypto;
using Best.HTTP.SecureProtocol.Org.BouncyCastle.Crypto.Parameters;
using Best.HTTP.SecureProtocol.Org.BouncyCastle.Crypto.Utilities;
using Best.HTTP.SecureProtocol.Org.BouncyCastle.Utilities;

namespace Best.HTTP.Shared.TLS.Crypto.Impl
{
    /**
    * an implementation of the AES (Rijndael), from FIPS-197.
    * <p>
    * For further details see: <a href="http://csrc.nist.gov/encryption/aes/">http://csrc.nist.gov/encryption/aes/</a>.
    *
    * This implementation is based on optimizations from Dr. Brian Gladman's paper and C code at
    * <a href="http://fp.gladman.plus.com/cryptography_technology/rijndael/">http://fp.gladman.plus.com/cryptography_technology/rijndael/</a>
    *
    * There are three levels of tradeoff of speed vs memory
    * Because java has no preprocessor, they are written as three separate classes from which to choose
    *
    * The fastest uses 8Kbytes of static tables to precompute round calculations, 4 256 word tables for encryption
    * and 4 for decryption.
    *
    * The middle performance version uses only one 256 word table for each, for a total of 2Kbytes,
    * adding 12 rotate operations per round to compute the values contained in the other tables from
    * the contents of the first.
    *
    * The slowest version uses no static tables at all and computes the values in each round.
    * </p>
    * <p>
    * This file contains the middle performance version with 2Kbytes of static tables for round precomputation.
    * </p>
    */

    [Best.HTTP.Shared.PlatformSupport.IL2CPP.Il2CppEagerStaticClassConstructionAttribute]
    public sealed class FastAesEngine
        : IBlockCipher
    {
        // The S box
        private static readonly byte[] S =
        {
            99, 124, 119, 123, 242, 107, 111, 197,
            48,   1, 103,  43, 254, 215, 171, 118,
            202, 130, 201, 125, 250,  89,  71, 240,
            173, 212, 162, 175, 156, 164, 114, 192,
            183, 253, 147,  38,  54,  63, 247, 204,
            52, 165, 229, 241, 113, 216,  49,  21,
            4, 199,  35, 195,  24, 150,   5, 154,
            7,  18, 128, 226, 235,  39, 178, 117,
            9, 131,  44,  26,  27, 110,  90, 160,
            82,  59, 214, 179,  41, 227,  47, 132,
            83, 209,   0, 237,  32, 252, 177,  91,
            106, 203, 190,  57,  74,  76,  88, 207,
            208, 239, 170, 251,  67,  77,  51, 133,
            69, 249,   2, 127,  80,  60, 159, 168,
            81, 163,  64, 143, 146, 157,  56, 245,
            188, 182, 218,  33,  16, 255, 243, 210,
            205,  12,  19, 236,  95, 151,  68,  23,
            196, 167, 126,  61, 100,  93,  25, 115,
            96, 129,  79, 220,  34,  42, 144, 136,
            70, 238, 184,  20, 222,  94,  11, 219,
            224,  50,  58,  10,  73,   6,  36,  92,
            194, 211, 172,  98, 145, 149, 228, 121,
            231, 200,  55, 109, 141, 213,  78, 169,
            108,  86, 244, 234, 101, 122, 174,   8,
            186, 120,  37,  46,  28, 166, 180, 198,
            232, 221, 116,  31,  75, 189, 139, 138,
            112,  62, 181, 102,  72,   3, 246,  14,
            97,  53,  87, 185, 134, 193,  29, 158,
            225, 248, 152,  17, 105, 217, 142, 148,
            155,  30, 135, 233, 206,  85,  40, 223,
            140, 161, 137,  13, 191, 230,  66, 104,
            65, 153,  45,  15, 176,  84, 187,  22,
        };

        // The inverse S-box
        private static readonly byte[] Si =
        {
            82,   9, 106, 213,  48,  54, 165,  56,
            191,  64, 163, 158, 129, 243, 215, 251,
            124, 227,  57, 130, 155,  47, 255, 135,
            52, 142,  67,  68, 196, 222, 233, 203,
            84, 123, 148,  50, 166, 194,  35,  61,
            238,  76, 149,  11,  66, 250, 195,  78,
            8,  46, 161, 102,  40, 217,  36, 178,
            118,  91, 162,  73, 109, 139, 209,  37,
            114, 248, 246, 100, 134, 104, 152,  22,
            212, 164,  92, 204,  93, 101, 182, 146,
            108, 112,  72,  80, 253, 237, 185, 218,
            94,  21,  70,  87, 167, 141, 157, 132,
            144, 216, 171,   0, 140, 188, 211,  10,
            247, 228,  88,   5, 184, 179,  69,   6,
            208,  44,  30, 143, 202,  63,  15,   2,
            193, 175, 189,   3,   1,  19, 138, 107,
            58, 145,  17,  65,  79, 103, 220, 234,
            151, 242, 207, 206, 240, 180, 230, 115,
            150, 172, 116,  34, 231, 173,  53, 133,
            226, 249,  55, 232,  28, 117, 223, 110,
            71, 241,  26, 113,  29,  41, 197, 137,
            111, 183,  98,  14, 170,  24, 190,  27,
            252,  86,  62,  75, 198, 210, 121,  32,
            154, 219, 192, 254, 120, 205,  90, 244,
            31, 221, 168,  51, 136,   7, 199,  49,
            177,  18,  16,  89,  39, 128, 236,  95,
            96,  81, 127, 169,  25, 181,  74,  13,
            45, 229, 122, 159, 147, 201, 156, 239,
            160, 224,  59,  77, 174,  42, 245, 176,
            200, 235, 187,  60, 131,  83, 153,  97,
            23,  43,   4, 126, 186, 119, 214,  38,
            225, 105,  20,  99,  85,  33,  12, 125,
        };

        // vector used in calculating key schedule (powers of x in GF(256))
        private static readonly byte[] rcon =
        {
            0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a,
            0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91
        };

        // precomputation tables of calculations for rounds
        private static readonly uint[] T0 =
        {
            0xa56363c6, 0x847c7cf8, 0x997777ee, 0x8d7b7bf6, 0x0df2f2ff,
            0xbd6b6bd6, 0xb16f6fde, 0x54c5c591, 0x50303060, 0x03010102,
            0xa96767ce, 0x7d2b2b56, 0x19fefee7, 0x62d7d7b5, 0xe6abab4d,
            0x9a7676ec, 0x45caca8f, 0x9d82821f, 0x40c9c989, 0x877d7dfa,
            0x15fafaef, 0xeb5959b2, 0xc947478e, 0x0bf0f0fb, 0xecadad41,
            0x67d4d4b3, 0xfda2a25f, 0xeaafaf45, 0xbf9c9c23, 0xf7a4a453,
            0x967272e4, 0x5bc0c09b, 0xc2b7b775, 0x1cfdfde1, 0xae93933d,
            0x6a26264c, 0x5a36366c, 0x413f3f7e, 0x02f7f7f5, 0x4fcccc83,
            0x5c343468, 0xf4a5a551, 0x34e5e5d1, 0x08f1f1f9, 0x937171e2,
            0x73d8d8ab, 0x53313162, 0x3f15152a, 0x0c040408, 0x52c7c795,
            0x65232346, 0x5ec3c39d, 0x28181830, 0xa1969637, 0x0f05050a,
            0xb59a9a2f, 0x0907070e, 0x36121224, 0x9b80801b, 0x3de2e2df,
            0x26ebebcd, 0x6927274e, 0xcdb2b27f, 0x9f7575ea, 0x1b090912,
            0x9e83831d, 0x742c2c58, 0x2e1a1a34, 0x2d1b1b36, 0xb26e6edc,
            0xee5a5ab4, 0xfba0a05b, 0xf65252a4, 0x4d3b3b76, 0x61d6d6b7,
            0xceb3b37d, 0x7b292952, 0x3ee3e3dd, 0x712f2f5e, 0x97848413,
            0xf55353a6, 0x68d1d1b9, 0x00000000, 0x2cededc1, 0x60202040,
            0x1ffcfce3, 0xc8b1b179, 0xed5b5bb6, 0xbe6a6ad4, 0x46cbcb8d,
            0xd9bebe67, 0x4b393972, 0xde4a4a94, 0xd44c4c98, 0xe85858b0,
            0x4acfcf85, 0x6bd0d0bb, 0x2aefefc5, 0xe5aaaa4f, 0x16fbfbed,
            0xc5434386, 0xd74d4d9a, 0x55333366, 0x94858511, 0xcf45458a,
            0x10f9f9e9, 0x06020204, 0x817f7ffe, 0xf05050a0, 0x443c3c78,
            0xba9f9f25, 0xe3a8a84b, 0xf35151a2, 0xfea3a35d, 0xc0404080,
            0x8a8f8f05, 0xad92923f, 0xbc9d9d21, 0x48383870, 0x04f5f5f1,
            0xdfbcbc63, 0xc1b6b677, 0x75dadaaf, 0x63212142, 0x30101020,
            0x1affffe5, 0x0ef3f3fd, 0x6dd2d2bf, 0x4ccdcd81, 0x140c0c18,
            0x35131326, 0x2fececc3, 0xe15f5fbe, 0xa2979735, 0xcc444488,
            0x3917172e, 0x57c4c493, 0xf2a7a755, 0x827e7efc, 0x473d3d7a,
            0xac6464c8, 0xe75d5dba, 0x2b191932, 0x957373e6, 0xa06060c0,
            0x98818119, 0xd14f4f9e, 0x7fdcdca3, 0x66222244, 0x7e2a2a54,
            0xab90903b, 0x8388880b, 0xca46468c, 0x29eeeec7, 0xd3b8b86b,
            0x3c141428, 0x79dedea7, 0xe25e5ebc, 0x1d0b0b16, 0x76dbdbad,
            0x3be0e0db, 0x56323264, 0x4e3a3a74, 0x1e0a0a14, 0xdb494992,
            0x0a06060c, 0x6c242448, 0xe45c5cb8, 0x5dc2c29f, 0x6ed3d3bd,
            0xefacac43, 0xa66262c4, 0xa8919139, 0xa4959531, 0x37e4e4d3,
            0x8b7979f2, 0x32e7e7d5, 0x43c8c88b, 0x5937376e, 0xb76d6dda,
            0x8c8d8d01, 0x64d5d5b1, 0xd24e4e9c, 0xe0a9a949, 0xb46c6cd8,
            0xfa5656ac, 0x07f4f4f3, 0x25eaeacf, 0xaf6565ca, 0x8e7a7af4,
            0xe9aeae47, 0x18080810, 0xd5baba6f, 0x887878f0, 0x6f25254a,
            0x722e2e5c, 0x241c1c38, 0xf1a6a657, 0xc7b4b473, 0x51c6c697,
            0x23e8e8cb, 0x7cdddda1, 0x9c7474e8, 0x211f1f3e, 0xdd4b4b96,
            0xdcbdbd61, 0x868b8b0d, 0x858a8a0f, 0x907070e0, 0x423e3e7c,
            0xc4b5b571, 0xaa6666cc, 0xd8484890, 0x05030306, 0x01f6f6f7,
            0x120e0e1c, 0xa36161c2, 0x5f35356a, 0xf95757ae, 0xd0b9b969,
            0x91868617, 0x58c1c199, 0x271d1d3a, 0xb99e9e27, 0x38e1e1d9,
            0x13f8f8eb, 0xb398982b, 0x33111122, 0xbb6969d2, 0x70d9d9a9,
            0x898e8e07, 0xa7949433, 0xb69b9b2d, 0x221e1e3c, 0x92878715,
            0x20e9e9c9, 0x49cece87, 0xff5555aa, 0x78282850, 0x7adfdfa5,
            0x8f8c8c03, 0xf8a1a159, 0x80898909, 0x170d0d1a, 0xdabfbf65,
            0x31e6e6d7, 0xc6424284, 0xb86868d0, 0xc3414182, 0xb0999929,
            0x772d2d5a, 0x110f0f1e, 0xcbb0b07b, 0xfc5454a8, 0xd6bbbb6d,
            0x3a16162c
        };

        private static readonly uint[] Tinv0 =
        {
            0x50a7f451, 0x5365417e, 0xc3a4171a, 0x965e273a, 0xcb6bab3b,
            0xf1459d1f, 0xab58faac, 0x9303e34b, 0x55fa3020, 0xf66d76ad,
            0x9176cc88, 0x254c02f5, 0xfcd7e54f, 0xd7cb2ac5, 0x80443526,
            0x8fa362b5, 0x495ab1de, 0x671bba25, 0x980eea45, 0xe1c0fe5d,
            0x02752fc3, 0x12f04c81, 0xa397468d, 0xc6f9d36b, 0xe75f8f03,
            0x959c9215, 0xeb7a6dbf, 0xda595295, 0x2d83bed4, 0xd3217458,
            0x2969e049, 0x44c8c98e, 0x6a89c275, 0x78798ef4, 0x6b3e5899,
            0xdd71b927, 0xb64fe1be, 0x17ad88f0, 0x66ac20c9, 0xb43ace7d,
            0x184adf63, 0x82311ae5, 0x60335197, 0x457f5362, 0xe07764b1,
            0x84ae6bbb, 0x1ca081fe, 0x942b08f9, 0x58684870, 0x19fd458f,
            0x876cde94, 0xb7f87b52, 0x23d373ab, 0xe2024b72, 0x578f1fe3,
            0x2aab5566, 0x0728ebb2, 0x03c2b52f, 0x9a7bc586, 0xa50837d3,
            0xf2872830, 0xb2a5bf23, 0xba6a0302, 0x5c8216ed, 0x2b1ccf8a,
            0x92b479a7, 0xf0f207f3, 0xa1e2694e, 0xcdf4da65, 0xd5be0506,
            0x1f6234d1, 0x8afea6c4, 0x9d532e34, 0xa055f3a2, 0x32e18a05,
            0x75ebf6a4, 0x39ec830b, 0xaaef6040, 0x069f715e, 0x51106ebd,
            0xf98a213e, 0x3d06dd96, 0xae053edd, 0x46bde64d, 0xb58d5491,
            0x055dc471, 0x6fd40604, 0xff155060, 0x24fb9819, 0x97e9bdd6,
            0xcc434089, 0x779ed967, 0xbd42e8b0, 0x888b8907, 0x385b19e7,
            0xdbeec879, 0x470a7ca1, 0xe90f427c, 0xc91e84f8, 0x00000000,
            0x83868009, 0x48ed2b32, 0xac70111e, 0x4e725a6c, 0xfbff0efd,
            0x5638850f, 0x1ed5ae3d, 0x27392d36, 0x64d90f0a, 0x21a65c68,
            0xd1545b9b, 0x3a2e3624, 0xb1670a0c, 0x0fe75793, 0xd296eeb4,
            0x9e919b1b, 0x4fc5c080, 0xa220dc61, 0x694b775a, 0x161a121c,
            0x0aba93e2, 0xe52aa0c0, 0x43e0223c, 0x1d171b12, 0x0b0d090e,
            0xadc78bf2, 0xb9a8b62d, 0xc8a91e14, 0x8519f157, 0x4c0775af,
            0xbbdd99ee, 0xfd607fa3, 0x9f2601f7, 0xbcf5725c, 0xc53b6644,
            0x347efb5b, 0x7629438b, 0xdcc623cb, 0x68fcedb6, 0x63f1e4b8,
            0xcadc31d7, 0x10856342, 0x40229713, 0x2011c684, 0x7d244a85,
            0xf83dbbd2, 0x1132f9ae, 0x6da129c7, 0x4b2f9e1d, 0xf330b2dc,
            0xec52860d, 0xd0e3c177, 0x6c16b32b, 0x99b970a9, 0xfa489411,
            0x2264e947, 0xc48cfca8, 0x1a3ff0a0, 0xd82c7d56, 0xef903322,
            0xc74e4987, 0xc1d138d9, 0xfea2ca8c, 0x360bd498, 0xcf81f5a6,
            0x28de7aa5, 0x268eb7da, 0xa4bfad3f, 0xe49d3a2c, 0x0d927850,
            0x9bcc5f6a, 0x62467e54, 0xc2138df6, 0xe8b8d890, 0x5ef7392e,
            0xf5afc382, 0xbe805d9f, 0x7c93d069, 0xa92dd56f, 0xb31225cf,
            0x3b99acc8, 0xa77d1810, 0x6e639ce8, 0x7bbb3bdb, 0x097826cd,
            0xf418596e, 0x01b79aec, 0xa89a4f83, 0x656e95e6, 0x7ee6ffaa,
            0x08cfbc21, 0xe6e815ef, 0xd99be7ba, 0xce366f4a, 0xd4099fea,
            0xd67cb029, 0xafb2a431, 0x31233f2a, 0x3094a5c6, 0xc066a235,
            0x37bc4e74, 0xa6ca82fc, 0xb0d090e0, 0x15d8a733, 0x4a9804f1,
            0xf7daec41, 0x0e50cd7f, 0x2ff69117, 0x8dd64d76, 0x4db0ef43,
            0x544daacc, 0xdf0496e4, 0xe3b5d19e, 0x1b886a4c, 0xb81f2cc1,
            0x7f516546, 0x04ea5e9d, 0x5d358c01, 0x737487fa, 0x2e410bfb,
            0x5a1d67b3, 0x52d2db92, 0x335610e9, 0x1347d66d, 0x8c61d79a,
            0x7a0ca137, 0x8e14f859, 0x893c13eb, 0xee27a9ce, 0x35c961b7,
            0xede51ce1, 0x3cb1477a, 0x59dfd29c, 0x3f73f255, 0x79ce1418,
            0xbf37c773, 0xeacdf753, 0x5baafd5f, 0x146f3ddf, 0x86db4478,
            0x81f3afca, 0x3ec468b9, 0x2c342438, 0x5f40a3c2, 0x72c31d16,
            0x0c25e2bc, 0x8b493c28, 0x41950dff, 0x7101a839, 0xdeb30c08,
            0x9ce4b4d8, 0x90c15664, 0x6184cb7b, 0x70b632d5, 0x745c6c48,
            0x4257b8d0
        };

        private static uint Shift(uint r, int shift)
        {
            return (r >> shift) | (r << (32 - shift));
        }

        /* multiply four bytes in GF(2^8) by 'x' {02} in parallel */

        private const uint m1 = 0x80808080;
        private const uint m2 = 0x7f7f7f7f;
        private const uint m3 = 0x0000001b;
        private const uint m4 = 0xC0C0C0C0;
        private const uint m5 = 0x3f3f3f3f;

        private static uint FFmulX(uint x)
        {
            return ((x & m2) << 1) ^ (((x & m1) >> 7) * m3);
        }

        private static uint FFmulX2(uint x)
        {
            uint t0 = (x & m5) << 2;
            uint t1 = (x & m4);
            t1 ^= (t1 >> 1);
            return t0 ^ (t1 >> 2) ^ (t1 >> 5);
        }

        /*
        The following defines provide alternative definitions of FFmulX that might
        give improved performance if a fast 32-bit multiply is not available.

        private int FFmulX(int x) { int u = x & m1; u |= (u >> 1); return ((x & m2) << 1) ^ ((u >>> 3) | (u >>> 6)); }
        private static final int  m4 = 0x1b1b1b1b;
        private int FFmulX(int x) { int u = x & m1; return ((x & m2) << 1) ^ ((u - (u >>> 7)) & m4); }

        */

        private static uint Inv_Mcol(uint x)
        {
            uint t0, t1;
            t0 = x;
            t1 = t0 ^ Shift(t0, 8);
            t0 ^= FFmulX(t1);
            t1 ^= FFmulX2(t0);
            t0 ^= t1 ^ Shift(t1, 16);
            return t0;
        }

        private static uint SubWord(uint x)
        {
            return (uint)S[x & 255]
                | (((uint)S[(x >> 8) & 255]) << 8)
                | (((uint)S[(x >> 16) & 255]) << 16)
                | (((uint)S[(x >> 24) & 255]) << 24);
        }

        uint[][] W = null;

        /**
        * Calculate the necessary round keys
        * The number of calculations depends on key size and block size
        * AES specified a fixed block size of 128 bits and key sizes 128/192/256 bits
        * This code is written assuming those are the only possible values
        */
        private uint[][] GenerateWorkingKey(byte[] key, bool forEncryption)
        {
            int keyLen = key.Length;
            if (keyLen < 16 || keyLen > 32 || (keyLen & 7) != 0)
                throw new ArgumentException("Key length not 128/192/256 bits.");

            int KC = keyLen >> 2;
            this.ROUNDS = KC + 6;  // This is not always true for the generalized Rijndael that allows larger block sizes

            if (W == null || W.Length < ROUNDS + 1)
            {
                W = new uint[ROUNDS + 1][]; // 4 words in a block
                for (int i = 0; i <= ROUNDS; ++i)
                {
                    W[i] = new uint[4];
                }
            }
            else
            {
                for (int i = 0; i < W.Length; ++i)
                    Array.Clear(W[i], 0, W[i].Length);
            }

            switch (KC)
            {
                case 4:
                    {
                        uint t0 = Pack.LE_To_UInt32(key, 0); W[0][0] = t0;
                        uint t1 = Pack.LE_To_UInt32(key, 4); W[0][1] = t1;
                        uint t2 = Pack.LE_To_UInt32(key, 8); W[0][2] = t2;
                        uint t3 = Pack.LE_To_UInt32(key, 12); W[0][3] = t3;

                        for (int i = 1; i <= 10; ++i)
                        {
                            uint u = SubWord(Shift(t3, 8)) ^ rcon[i - 1];
                            t0 ^= u; W[i][0] = t0;
                            t1 ^= t0; W[i][1] = t1;
                            t2 ^= t1; W[i][2] = t2;
                            t3 ^= t2; W[i][3] = t3;
                        }

                        break;
                    }
                case 6:
                    {
                        uint t0 = Pack.LE_To_UInt32(key, 0); W[0][0] = t0;
                        uint t1 = Pack.LE_To_UInt32(key, 4); W[0][1] = t1;
                        uint t2 = Pack.LE_To_UInt32(key, 8); W[0][2] = t2;
                        uint t3 = Pack.LE_To_UInt32(key, 12); W[0][3] = t3;
                        uint t4 = Pack.LE_To_UInt32(key, 16); W[1][0] = t4;
                        uint t5 = Pack.LE_To_UInt32(key, 20); W[1][1] = t5;

                        uint rcon = 1;
                        uint u = SubWord(Shift(t5, 8)) ^ rcon; rcon <<= 1;
                        t0 ^= u; W[1][2] = t0;
                        t1 ^= t0; W[1][3] = t1;
                        t2 ^= t1; W[2][0] = t2;
                        t3 ^= t2; W[2][1] = t3;
                        t4 ^= t3; W[2][2] = t4;
                        t5 ^= t4; W[2][3] = t5;

                        for (int i = 3; i < 12; i += 3)
                        {
                            u = SubWord(Shift(t5, 8)) ^ rcon; rcon <<= 1;
                            t0 ^= u; W[i][0] = t0;
                            t1 ^= t0; W[i][1] = t1;
                            t2 ^= t1; W[i][2] = t2;
                            t3 ^= t2; W[i][3] = t3;
                            t4 ^= t3; W[i + 1][0] = t4;
                            t5 ^= t4; W[i + 1][1] = t5;
                            u = SubWord(Shift(t5, 8)) ^ rcon; rcon <<= 1;
                            t0 ^= u; W[i + 1][2] = t0;
                            t1 ^= t0; W[i + 1][3] = t1;
                            t2 ^= t1; W[i + 2][0] = t2;
                            t3 ^= t2; W[i + 2][1] = t3;
                            t4 ^= t3; W[i + 2][2] = t4;
                            t5 ^= t4; W[i + 2][3] = t5;
                        }

                        u = SubWord(Shift(t5, 8)) ^ rcon;
                        t0 ^= u; W[12][0] = t0;
                        t1 ^= t0; W[12][1] = t1;
                        t2 ^= t1; W[12][2] = t2;
                        t3 ^= t2; W[12][3] = t3;

                        break;
                    }
                case 8:
                    {
                        uint t0 = Pack.LE_To_UInt32(key, 0); W[0][0] = t0;
                        uint t1 = Pack.LE_To_UInt32(key, 4); W[0][1] = t1;
                        uint t2 = Pack.LE_To_UInt32(key, 8); W[0][2] = t2;
                        uint t3 = Pack.LE_To_UInt32(key, 12); W[0][3] = t3;
                        uint t4 = Pack.LE_To_UInt32(key, 16); W[1][0] = t4;
                        uint t5 = Pack.LE_To_UInt32(key, 20); W[1][1] = t5;
                        uint t6 = Pack.LE_To_UInt32(key, 24); W[1][2] = t6;
                        uint t7 = Pack.LE_To_UInt32(key, 28); W[1][3] = t7;

                        uint u, rcon = 1;

                        for (int i = 2; i < 14; i += 2)
                        {
                            u = SubWord(Shift(t7, 8)) ^ rcon; rcon <<= 1;
                            t0 ^= u; W[i][0] = t0;
                            t1 ^= t0; W[i][1] = t1;
                            t2 ^= t1; W[i][2] = t2;
                            t3 ^= t2; W[i][3] = t3;
                            u = SubWord(t3);
                            t4 ^= u; W[i + 1][0] = t4;
                            t5 ^= t4; W[i + 1][1] = t5;
                            t6 ^= t5; W[i + 1][2] = t6;
                            t7 ^= t6; W[i + 1][3] = t7;
                        }

                        u = SubWord(Shift(t7, 8)) ^ rcon;
                        t0 ^= u; W[14][0] = t0;
                        t1 ^= t0; W[14][1] = t1;
                        t2 ^= t1; W[14][2] = t2;
                        t3 ^= t2; W[14][3] = t3;

                        break;
                    }
                default:
                    {
                        throw new InvalidOperationException("Should never get here");
                    }
            }

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

            return W;
        }

        private int ROUNDS;
        private uint[][] WorkingKey;
        private bool forEncryption;

        private byte[] s;

        private const int BLOCK_SIZE = 16;

        /**
        * default constructor - 128 bit block size.
        */
        public FastAesEngine()
        {
        }

        /**
        * initialise an AES cipher.
        *
        * @param forEncryption whether or not we are for encryption.
        * @param parameters the parameters required to set up the cipher.
        * @exception ArgumentException if the parameters argument is
        * inappropriate.
        */
        public void Init(bool forEncryption, ICipherParameters parameters)
        {
            if (!(parameters is KeyParameter keyParameter))
                throw new ArgumentException("invalid parameter passed to AES init - "
                    + Best.HTTP.SecureProtocol.Org.BouncyCastle.Utilities.Platform.GetTypeName(parameters));

            WorkingKey = GenerateWorkingKey(keyParameter.GetKey(), forEncryption);

            this.forEncryption = forEncryption;
            this.s = /*Arrays.Clone*/(forEncryption ? S : Si);
        }

        public string AlgorithmName
        {
            get { return "AES"; }
        }

        public int GetBlockSize()
        {
            return BLOCK_SIZE;
        }

        public int ProcessBlock(byte[] input, int inOff, byte[] output, int outOff)
        {
            if (WorkingKey == null)
                throw new InvalidOperationException("AES engine not initialised");

            Check.DataLength(input, inOff, 16, "input buffer too short");
            Check.OutputLength(output, outOff, 16, "output buffer too short");

#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER || UNITY_2021_2_OR_NEWER
            if (forEncryption)
            {
                EncryptBlock(input.AsSpan(inOff), output.AsSpan(outOff), WorkingKey);
            }
            else
            {
                DecryptBlock(input.AsSpan(inOff), output.AsSpan(outOff), WorkingKey);
            }
#else
            if (forEncryption)
            {
                EncryptBlock(input, inOff, output, outOff, WorkingKey);
            }
            else
            {
                DecryptBlock(input, inOff, output, outOff, WorkingKey);
            }
#endif

            return BLOCK_SIZE;
        }

#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER || UNITY_2021_2_OR_NEWER
        public unsafe int ProcessBlock(ReadOnlySpan<byte> input, Span<byte> output)
        {
            if (WorkingKey == null)
                throw new InvalidOperationException("AES engine not initialised");

            Check.DataLength(input, 16, "input buffer too short");
            Check.OutputLength(output, 16, "output buffer too short");

            if (forEncryption)
            {
                //EncryptBlock(input, output, WorkingKey);

                uint C0 = System.Buffers.Binary.BinaryPrimitives.ReadUInt32LittleEndian(input);
                uint C1 = System.Buffers.Binary.BinaryPrimitives.ReadUInt32LittleEndian(input[4..]);
                uint C2 = System.Buffers.Binary.BinaryPrimitives.ReadUInt32LittleEndian(input[8..]);
                uint C3 = System.Buffers.Binary.BinaryPrimitives.ReadUInt32LittleEndian(input[12..]);

                uint[] kw = WorkingKey[0];
                uint t0 = C0 ^ kw[0];
                uint t1 = C1 ^ kw[1];
                uint t2 = C2 ^ kw[2];

                uint r0, r1, r2, r3 = C3 ^ kw[3];
                int r = 1;
                uint tmp1, tmp2, tmp3;
                uint shift1, shift2, shift3;

                fixed (uint* pT0 = T0)
                {
                    while (r < ROUNDS - 1)
                    {
                        kw = WorkingKey[r++];
                        fixed (uint* pkw = kw)
                        {
                            tmp1 = pT0[(t1 >> 8) & 255]; tmp2 = pT0[(t2 >> 16) & 255]; tmp3 = pT0[(r3 >> 24) & 255];
                            shift1 = (tmp1 >> 24) | (tmp1 << 8); shift2 = (tmp2 >> 16) | (tmp2 << 16); shift3 = (tmp3 >> 8) | (tmp3 << 24);
                            r0 = pT0[t0 & 255] ^ shift1 ^ shift2 ^ shift3 ^ pkw[0];

                            tmp1 = pT0[(t2 >> 8) & 255]; tmp2 = pT0[(r3 >> 16) & 255]; tmp3 = pT0[(t0 >> 24) & 255];
                            shift1 = (tmp1 >> 24) | (tmp1 << 8); shift2 = (tmp2 >> 16) | (tmp2 << 16); shift3 = (tmp3 >> 8) | (tmp3 << 24);
                            r1 = pT0[t1 & 255] ^ shift1 ^ shift2 ^ shift3 ^ pkw[1];

                            tmp1 = pT0[(r3 >> 8) & 255]; tmp2 = pT0[(t0 >> 16) & 255]; tmp3 = pT0[(t1 >> 24) & 255];
                            shift1 = (tmp1 >> 24) | (tmp1 << 8); shift2 = (tmp2 >> 16) | (tmp2 << 16); shift3 = (tmp3 >> 8) | (tmp3 << 24);
                            r2 = pT0[t2 & 255] ^ shift1 ^ shift2 ^ shift3 ^ pkw[2];

                            tmp1 = pT0[(t0 >> 8) & 255]; tmp2 = pT0[(t1 >> 16) & 255]; tmp3 = pT0[(t2 >> 24) & 255];
                            shift1 = (tmp1 >> 24) | (tmp1 << 8); shift2 = (tmp2 >> 16) | (tmp2 << 16); shift3 = (tmp3 >> 8) | (tmp3 << 24);
                            r3 = pT0[r3 & 255] ^ shift1 ^ shift2 ^ shift3 ^ pkw[3];
                        }

                        kw = WorkingKey[r++];

                        fixed (uint* pkw = kw)
                        {
                            tmp1 = pT0[(r1 >> 8) & 255]; tmp2 = pT0[(r2 >> 16) & 255]; tmp3 = pT0[(r3 >> 24) & 255];
                            shift1 = (tmp1 >> 24) | (tmp1 << 8); shift2 = (tmp2 >> 16) | (tmp2 << 16); shift3 = (tmp3 >> 8) | (tmp3 << 24);
                            t0 = pT0[r0 & 255] ^ shift1 ^ shift2 ^ shift3 ^ pkw[0];

                            tmp1 = pT0[(r2 >> 8) & 255]; tmp2 = pT0[(r3 >> 16) & 255]; tmp3 = pT0[(r0 >> 24) & 255];
                            shift1 = (tmp1 >> 24) | (tmp1 << 8); shift2 = (tmp2 >> 16) | (tmp2 << 16); shift3 = (tmp3 >> 8) | (tmp3 << 24);
                            t1 = pT0[r1 & 255] ^ shift1 ^ shift2 ^ shift3 ^ pkw[1];

                            tmp1 = pT0[(r3 >> 8) & 255]; tmp2 = pT0[(r0 >> 16) & 255]; tmp3 = pT0[(r1 >> 24) & 255];
                            shift1 = (tmp1 >> 24) | (tmp1 << 8); shift2 = (tmp2 >> 16) | (tmp2 << 16); shift3 = (tmp3 >> 8) | (tmp3 << 24);
                            t2 = pT0[r2 & 255] ^ shift1 ^ shift2 ^ shift3 ^ pkw[2];

                            tmp1 = pT0[(r0 >> 8) & 255]; tmp2 = pT0[(r1 >> 16) & 255]; tmp3 = pT0[(r2 >> 24) & 255];
                            shift1 = (tmp1 >> 24) | (tmp1 << 8); shift2 = (tmp2 >> 16) | (tmp2 << 16); shift3 = (tmp3 >> 8) | (tmp3 << 24);
                            r3 = pT0[r3 & 255] ^ shift1 ^ shift2 ^ shift3 ^ pkw[3];
                        }
                    }

                    kw = WorkingKey[r++];
                    fixed (uint* pkw = kw)
                    {
                        tmp1 = pT0[(t1 >> 8) & 255]; tmp2 = pT0[(t2 >> 16) & 255]; tmp3 = pT0[(r3 >> 24) & 255];
                        shift1 = (tmp1 >> 24) | (tmp1 << 8); shift2 = (tmp2 >> 16) | (tmp2 << 16); shift3 = (tmp3 >> 8) | (tmp3 << 24);
                        r0 = pT0[t0 & 255] ^ shift1 ^ shift2 ^ shift3 ^ pkw[0];

                        tmp1 = pT0[(t2 >> 8) & 255]; tmp2 = pT0[(r3 >> 16) & 255]; tmp3 = pT0[(t0 >> 24) & 255];
                        shift1 = (tmp1 >> 24) | (tmp1 << 8); shift2 = (tmp2 >> 16) | (tmp2 << 16); shift3 = (tmp3 >> 8) | (tmp3 << 24);
                        r1 = pT0[t1 & 255] ^ shift1 ^ shift2 ^ shift3 ^ pkw[1];

                        tmp1 = pT0[(r3 >> 8) & 255]; tmp2 = pT0[(t0 >> 16) & 255]; tmp3 = pT0[(t1 >> 24) & 255];
                        shift1 = (tmp1 >> 24) | (tmp1 << 8); shift2 = (tmp2 >> 16) | (tmp2 << 16); shift3 = (tmp3 >> 8) | (tmp3 << 24);
                        r2 = pT0[t2 & 255] ^ shift1 ^ shift2 ^ shift3 ^ pkw[2];

                        tmp1 = pT0[(t0 >> 8) & 255]; tmp2 = pT0[(t1 >> 16) & 255]; tmp3 = pT0[(t2 >> 24) & 255];
                        shift1 = (tmp1 >> 24) | (tmp1 << 8); shift2 = (tmp2 >> 16) | (tmp2 << 16); shift3 = (tmp3 >> 8) | (tmp3 << 24);
                        r3 = pT0[r3 & 255] ^ shift1 ^ shift2 ^ shift3 ^ pkw[3];
                    }
                }

                // the final round's table is a simple function of S so we don't use a whole other four tables for it

                kw = WorkingKey[r];
                fixed (uint* pkw = kw)
                fixed (byte* pS = S)
                fixed (byte* ps = s)
                {
                    C0 = (uint)pS[r0 & 255] ^ (((uint)pS[(r1 >> 8) & 255]) << 8) ^ (((uint)ps[(r2 >> 16) & 255]) << 16) ^ (((uint)ps[(r3 >> 24) & 255]) << 24) ^ pkw[0];
                    C1 = (uint)ps[r1 & 255] ^ (((uint)pS[(r2 >> 8) & 255]) << 8) ^ (((uint)pS[(r3 >> 16) & 255]) << 16) ^ (((uint)ps[(r0 >> 24) & 255]) << 24) ^ pkw[1];
                    C2 = (uint)ps[r2 & 255] ^ (((uint)pS[(r3 >> 8) & 255]) << 8) ^ (((uint)pS[(r0 >> 16) & 255]) << 16) ^ (((uint)pS[(r1 >> 24) & 255]) << 24) ^ pkw[2];
                    C3 = (uint)ps[r3 & 255] ^ (((uint)ps[(r0 >> 8) & 255]) << 8) ^ (((uint)ps[(r1 >> 16) & 255]) << 16) ^ (((uint)pS[(r2 >> 24) & 255]) << 24) ^ pkw[3];
                }

                System.Buffers.Binary.BinaryPrimitives.WriteUInt32LittleEndian(output, C0);
                System.Buffers.Binary.BinaryPrimitives.WriteUInt32LittleEndian(output[4..], C1);
                System.Buffers.Binary.BinaryPrimitives.WriteUInt32LittleEndian(output[8..], C2);
                System.Buffers.Binary.BinaryPrimitives.WriteUInt32LittleEndian(output[12..], C3);
            }
            else
            {
                //DecryptBlock(input, output, WorkingKey);

                uint C0 = System.Buffers.Binary.BinaryPrimitives.ReadUInt32LittleEndian(input);
                uint C1 = System.Buffers.Binary.BinaryPrimitives.ReadUInt32LittleEndian(input[4..]);
                uint C2 = System.Buffers.Binary.BinaryPrimitives.ReadUInt32LittleEndian(input[8..]);
                uint C3 = System.Buffers.Binary.BinaryPrimitives.ReadUInt32LittleEndian(input[12..]);

                uint[] kw = WorkingKey[ROUNDS];
                uint t0 = C0 ^ kw[0];
                uint t1 = C1 ^ kw[1];
                uint t2 = C2 ^ kw[2];

                uint r0, r1, r2, r3 = C3 ^ kw[3];
                int r = ROUNDS - 1;

                uint tmp1, tmp2, tmp3;
                uint shift1, shift2, shift3;

                fixed (uint* pTinv0 = Tinv0)
                {
                    while (r > 1)
                    {
                        kw = WorkingKey[r--];
                        fixed (uint* pkw = kw)
                        {
                            tmp1 = pTinv0[(r3 >> 8) & 255]; tmp2 = pTinv0[(t2 >> 16) & 255]; tmp3 = pTinv0[(t1 >> 24) & 255];
                            shift1 = (tmp1 >> 24) | (tmp1 << 8); shift2 = (tmp2 >> 16) | (tmp2 << 16); shift3 = (tmp3 >> 8) | (tmp3 << 24);
                            r0 = pTinv0[t0 & 255] ^ shift1 ^ shift2 ^ shift3 ^ pkw[0];

                            tmp1 = pTinv0[(t0 >> 8) & 255]; tmp2 = pTinv0[(r3 >> 16) & 255]; tmp3 = pTinv0[(t2 >> 24) & 255];
                            shift1 = (tmp1 >> 24) | (tmp1 << 8); shift2 = (tmp2 >> 16) | (tmp2 << 16); shift3 = (tmp3 >> 8) | (tmp3 << 24);
                            r1 = pTinv0[t1 & 255] ^ shift1 ^ shift2 ^ shift3 ^ pkw[1];

                            tmp1 = pTinv0[(t1 >> 8) & 255]; tmp2 = pTinv0[(t0 >> 16) & 255]; tmp3 = pTinv0[(r3 >> 24) & 255];
                            shift1 = (tmp1 >> 24) | (tmp1 << 8); shift2 = (tmp2 >> 16) | (tmp2 << 16); shift3 = (tmp3 >> 8) | (tmp3 << 24);
                            r2 = pTinv0[t2 & 255] ^ shift1 ^ shift2 ^ shift3 ^ pkw[2];

                            tmp1 = pTinv0[(t2 >> 8) & 255]; tmp2 = pTinv0[(t1 >> 16) & 255]; tmp3 = pTinv0[(t0 >> 24) & 255];
                            shift1 = (tmp1 >> 24) | (tmp1 << 8); shift2 = (tmp2 >> 16) | (tmp2 << 16); shift3 = (tmp3 >> 8) | (tmp3 << 24);
                            r3 = pTinv0[r3 & 255] ^ shift1 ^ shift2 ^ shift3 ^ pkw[3];
                        }

                        kw = WorkingKey[r--];

                        fixed (uint* pkw = kw)
                        {
                            tmp1 = pTinv0[(r3 >> 8) & 255]; tmp2 = pTinv0[(r2 >> 16) & 255]; tmp3 = pTinv0[(r1 >> 24) & 255];
                            shift1 = (tmp1 >> 24) | (tmp1 << 8); shift2 = (tmp2 >> 16) | (tmp2 << 16); shift3 = (tmp3 >> 8) | (tmp3 << 24);
                            t0 = pTinv0[r0 & 255] ^ shift1 ^ shift2 ^ shift3 ^ pkw[0];

                            tmp1 = pTinv0[(r0 >> 8) & 255]; tmp2 = pTinv0[(r3 >> 16) & 255]; tmp3 = pTinv0[(r2 >> 24) & 255];
                            shift1 = (tmp1 >> 24) | (tmp1 << 8); shift2 = (tmp2 >> 16) | (tmp2 << 16); shift3 = (tmp3 >> 8) | (tmp3 << 24);
                            t1 = pTinv0[r1 & 255] ^ shift1 ^ shift2 ^ shift3 ^ pkw[1];

                            tmp1 = pTinv0[(r1 >> 8) & 255]; tmp2 = pTinv0[(r0 >> 16) & 255]; tmp3 = pTinv0[(r3 >> 24) & 255];
                            shift1 = (tmp1 >> 24) | (tmp1 << 8); shift2 = (tmp2 >> 16) | (tmp2 << 16); shift3 = (tmp3 >> 8) | (tmp3 << 24);
                            t2 = pTinv0[r2 & 255] ^ shift1 ^ shift2 ^ shift3 ^ pkw[2];

                            tmp1 = pTinv0[(r2 >> 8) & 255]; tmp2 = pTinv0[(r1 >> 16) & 255]; tmp3 = pTinv0[(r0 >> 24) & 255];
                            shift1 = (tmp1 >> 24) | (tmp1 << 8); shift2 = (tmp2 >> 16) | (tmp2 << 16); shift3 = (tmp3 >> 8) | (tmp3 << 24);
                            r3 = pTinv0[r3 & 255] ^ shift1 ^ shift2 ^ shift3 ^ pkw[3];
                        }
                    }

                    kw = WorkingKey[1];

                    fixed (uint* pkw = kw)
                    {
                        tmp1 = pTinv0[(r3 >> 8) & 255]; tmp2 = pTinv0[(t2 >> 16) & 255]; tmp3 = pTinv0[(t1 >> 24) & 255];
                        shift1 = (tmp1 >> 24) | (tmp1 << 8); shift2 = (tmp2 >> 16) | (tmp2 << 16); shift3 = (tmp3 >> 8) | (tmp3 << 24);
                        r0 = pTinv0[t0 & 255] ^ shift1 ^ shift2 ^ shift3 ^ pkw[0];

                        tmp1 = pTinv0[(t0 >> 8) & 255]; tmp2 = pTinv0[(r3 >> 16) & 255]; tmp3 = pTinv0[(t2 >> 24) & 255];
                        shift1 = (tmp1 >> 24) | (tmp1 << 8); shift2 = (tmp2 >> 16) | (tmp2 << 16); shift3 = (tmp3 >> 8) | (tmp3 << 24);
                        r1 = pTinv0[t1 & 255] ^ shift1 ^ shift2 ^ shift3 ^ pkw[1];

                        tmp1 = pTinv0[(t1 >> 8) & 255]; tmp2 = pTinv0[(t0 >> 16) & 255]; tmp3 = pTinv0[(r3 >> 24) & 255];
                        shift1 = (tmp1 >> 24) | (tmp1 << 8); shift2 = (tmp2 >> 16) | (tmp2 << 16); shift3 = (tmp3 >> 8) | (tmp3 << 24);
                        r2 = pTinv0[t2 & 255] ^ shift1 ^ shift2 ^ shift3 ^ pkw[2];

                        tmp1 = pTinv0[(t2 >> 8) & 255]; tmp2 = pTinv0[(t1 >> 16) & 255]; tmp3 = pTinv0[(t0 >> 24) & 255];
                        shift1 = (tmp1 >> 24) | (tmp1 << 8); shift2 = (tmp2 >> 16) | (tmp2 << 16); shift3 = (tmp3 >> 8) | (tmp3 << 24);
                        r3 = pTinv0[r3 & 255] ^ shift1 ^ shift2 ^ shift3 ^ pkw[3];
                    }
                }
                // the final round's table is a simple function of Si so we don't use a whole other four tables for it

                kw = WorkingKey[0];
                fixed (uint* pkw = kw)
                fixed(byte* pSi = Si)
                fixed (byte* ps = s)
                {
                    C0 = (uint)pSi[r0 & 255] ^ (((uint)ps[(r3 >> 8) & 255]) << 8) ^ (((uint)ps[(r2 >> 16) & 255]) << 16) ^ (((uint)pSi[(r1 >> 24) & 255]) << 24) ^ pkw[0];
                    C1 = (uint)ps[r1 & 255] ^ (((uint)ps[(r0 >> 8) & 255]) << 8) ^ (((uint)pSi[(r3 >> 16) & 255]) << 16) ^ (((uint)ps[(r2 >> 24) & 255]) << 24) ^ pkw[1];
                    C2 = (uint)ps[r2 & 255] ^ (((uint)pSi[(r1 >> 8) & 255]) << 8) ^ (((uint)pSi[(r0 >> 16) & 255]) << 16) ^ (((uint)ps[(r3 >> 24) & 255]) << 24) ^ pkw[2];
                    C3 = (uint)pSi[r3 & 255] ^ (((uint)ps[(r2 >> 8) & 255]) << 8) ^ (((uint)ps[(r1 >> 16) & 255]) << 16) ^ (((uint)ps[(r0 >> 24) & 255]) << 24) ^ pkw[3];
                }

                System.Buffers.Binary.BinaryPrimitives.WriteUInt32LittleEndian(output, C0);
                System.Buffers.Binary.BinaryPrimitives.WriteUInt32LittleEndian(output[4..], C1);
                System.Buffers.Binary.BinaryPrimitives.WriteUInt32LittleEndian(output[8..], C2);
                System.Buffers.Binary.BinaryPrimitives.WriteUInt32LittleEndian(output[12..], C3);
            }

            return BLOCK_SIZE;
        }
#endif

#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER || UNITY_2021_2_OR_NEWER
        private void EncryptBlock(ReadOnlySpan<byte> input, Span<byte> output, uint[][] KW)
        {
            uint C0 = Pack.LE_To_UInt32(input);
            uint C1 = Pack.LE_To_UInt32(input[4..]);
            uint C2 = Pack.LE_To_UInt32(input[8..]);
            uint C3 = Pack.LE_To_UInt32(input[12..]);

            uint[] kw = KW[0];
            uint t0 = C0 ^ kw[0];
            uint t1 = C1 ^ kw[1];
            uint t2 = C2 ^ kw[2];

            uint r0, r1, r2, r3 = C3 ^ kw[3];
            int r = 1;
            while (r < ROUNDS - 1)
            {
                kw = KW[r++];
                r0 = T0[t0 & 255] ^ Shift(T0[(t1 >> 8) & 255], 24) ^ Shift(T0[(t2 >> 16) & 255], 16) ^ Shift(T0[(r3 >> 24) & 255], 8) ^ kw[0];
                r1 = T0[t1 & 255] ^ Shift(T0[(t2 >> 8) & 255], 24) ^ Shift(T0[(r3 >> 16) & 255], 16) ^ Shift(T0[(t0 >> 24) & 255], 8) ^ kw[1];
                r2 = T0[t2 & 255] ^ Shift(T0[(r3 >> 8) & 255], 24) ^ Shift(T0[(t0 >> 16) & 255], 16) ^ Shift(T0[(t1 >> 24) & 255], 8) ^ kw[2];
                r3 = T0[r3 & 255] ^ Shift(T0[(t0 >> 8) & 255], 24) ^ Shift(T0[(t1 >> 16) & 255], 16) ^ Shift(T0[(t2 >> 24) & 255], 8) ^ kw[3];
                kw = KW[r++];
                t0 = T0[r0 & 255] ^ Shift(T0[(r1 >> 8) & 255], 24) ^ Shift(T0[(r2 >> 16) & 255], 16) ^ Shift(T0[(r3 >> 24) & 255], 8) ^ kw[0];
                t1 = T0[r1 & 255] ^ Shift(T0[(r2 >> 8) & 255], 24) ^ Shift(T0[(r3 >> 16) & 255], 16) ^ Shift(T0[(r0 >> 24) & 255], 8) ^ kw[1];
                t2 = T0[r2 & 255] ^ Shift(T0[(r3 >> 8) & 255], 24) ^ Shift(T0[(r0 >> 16) & 255], 16) ^ Shift(T0[(r1 >> 24) & 255], 8) ^ kw[2];
                r3 = T0[r3 & 255] ^ Shift(T0[(r0 >> 8) & 255], 24) ^ Shift(T0[(r1 >> 16) & 255], 16) ^ Shift(T0[(r2 >> 24) & 255], 8) ^ kw[3];
            }

            kw = KW[r++];
            r0 = T0[t0 & 255] ^ Shift(T0[(t1 >> 8) & 255], 24) ^ Shift(T0[(t2 >> 16) & 255], 16) ^ Shift(T0[(r3 >> 24) & 255], 8) ^ kw[0];
            r1 = T0[t1 & 255] ^ Shift(T0[(t2 >> 8) & 255], 24) ^ Shift(T0[(r3 >> 16) & 255], 16) ^ Shift(T0[(t0 >> 24) & 255], 8) ^ kw[1];
            r2 = T0[t2 & 255] ^ Shift(T0[(r3 >> 8) & 255], 24) ^ Shift(T0[(t0 >> 16) & 255], 16) ^ Shift(T0[(t1 >> 24) & 255], 8) ^ kw[2];
            r3 = T0[r3 & 255] ^ Shift(T0[(t0 >> 8) & 255], 24) ^ Shift(T0[(t1 >> 16) & 255], 16) ^ Shift(T0[(t2 >> 24) & 255], 8) ^ kw[3];

            // the final round's table is a simple function of S so we don't use a whole other four tables for it

            kw = KW[r];
            C0 = (uint)S[r0 & 255] ^ (((uint)S[(r1 >> 8) & 255]) << 8) ^ (((uint)s[(r2 >> 16) & 255]) << 16) ^ (((uint)s[(r3 >> 24) & 255]) << 24) ^ kw[0];
            C1 = (uint)s[r1 & 255] ^ (((uint)S[(r2 >> 8) & 255]) << 8) ^ (((uint)S[(r3 >> 16) & 255]) << 16) ^ (((uint)s[(r0 >> 24) & 255]) << 24) ^ kw[1];
            C2 = (uint)s[r2 & 255] ^ (((uint)S[(r3 >> 8) & 255]) << 8) ^ (((uint)S[(r0 >> 16) & 255]) << 16) ^ (((uint)S[(r1 >> 24) & 255]) << 24) ^ kw[2];
            C3 = (uint)s[r3 & 255] ^ (((uint)s[(r0 >> 8) & 255]) << 8) ^ (((uint)s[(r1 >> 16) & 255]) << 16) ^ (((uint)S[(r2 >> 24) & 255]) << 24) ^ kw[3];

            Pack.UInt32_To_LE(C0, output);
            Pack.UInt32_To_LE(C1, output[4..]);
            Pack.UInt32_To_LE(C2, output[8..]);
            Pack.UInt32_To_LE(C3, output[12..]);
        }

        private void DecryptBlock(ReadOnlySpan<byte> input, Span<byte> output, uint[][] KW)
        {
            uint C0 = Pack.LE_To_UInt32(input);
            uint C1 = Pack.LE_To_UInt32(input[4..]);
            uint C2 = Pack.LE_To_UInt32(input[8..]);
            uint C3 = Pack.LE_To_UInt32(input[12..]);

            uint[] kw = KW[ROUNDS];
            uint t0 = C0 ^ kw[0];
            uint t1 = C1 ^ kw[1];
            uint t2 = C2 ^ kw[2];

            uint r0, r1, r2, r3 = C3 ^ kw[3];
            int r = ROUNDS - 1;
            while (r > 1)
            {
                kw = KW[r--];
                r0 = Tinv0[t0 & 255] ^ Shift(Tinv0[(r3 >> 8) & 255], 24) ^ Shift(Tinv0[(t2 >> 16) & 255], 16) ^ Shift(Tinv0[(t1 >> 24) & 255], 8) ^ kw[0];
                r1 = Tinv0[t1 & 255] ^ Shift(Tinv0[(t0 >> 8) & 255], 24) ^ Shift(Tinv0[(r3 >> 16) & 255], 16) ^ Shift(Tinv0[(t2 >> 24) & 255], 8) ^ kw[1];
                r2 = Tinv0[t2 & 255] ^ Shift(Tinv0[(t1 >> 8) & 255], 24) ^ Shift(Tinv0[(t0 >> 16) & 255], 16) ^ Shift(Tinv0[(r3 >> 24) & 255], 8) ^ kw[2];
                r3 = Tinv0[r3 & 255] ^ Shift(Tinv0[(t2 >> 8) & 255], 24) ^ Shift(Tinv0[(t1 >> 16) & 255], 16) ^ Shift(Tinv0[(t0 >> 24) & 255], 8) ^ kw[3];
                kw = KW[r--];
                t0 = Tinv0[r0 & 255] ^ Shift(Tinv0[(r3 >> 8) & 255], 24) ^ Shift(Tinv0[(r2 >> 16) & 255], 16) ^ Shift(Tinv0[(r1 >> 24) & 255], 8) ^ kw[0];
                t1 = Tinv0[r1 & 255] ^ Shift(Tinv0[(r0 >> 8) & 255], 24) ^ Shift(Tinv0[(r3 >> 16) & 255], 16) ^ Shift(Tinv0[(r2 >> 24) & 255], 8) ^ kw[1];
                t2 = Tinv0[r2 & 255] ^ Shift(Tinv0[(r1 >> 8) & 255], 24) ^ Shift(Tinv0[(r0 >> 16) & 255], 16) ^ Shift(Tinv0[(r3 >> 24) & 255], 8) ^ kw[2];
                r3 = Tinv0[r3 & 255] ^ Shift(Tinv0[(r2 >> 8) & 255], 24) ^ Shift(Tinv0[(r1 >> 16) & 255], 16) ^ Shift(Tinv0[(r0 >> 24) & 255], 8) ^ kw[3];
            }

            kw = KW[1];
            r0 = Tinv0[t0 & 255] ^ Shift(Tinv0[(r3 >> 8) & 255], 24) ^ Shift(Tinv0[(t2 >> 16) & 255], 16) ^ Shift(Tinv0[(t1 >> 24) & 255], 8) ^ kw[0];
            r1 = Tinv0[t1 & 255] ^ Shift(Tinv0[(t0 >> 8) & 255], 24) ^ Shift(Tinv0[(r3 >> 16) & 255], 16) ^ Shift(Tinv0[(t2 >> 24) & 255], 8) ^ kw[1];
            r2 = Tinv0[t2 & 255] ^ Shift(Tinv0[(t1 >> 8) & 255], 24) ^ Shift(Tinv0[(t0 >> 16) & 255], 16) ^ Shift(Tinv0[(r3 >> 24) & 255], 8) ^ kw[2];
            r3 = Tinv0[r3 & 255] ^ Shift(Tinv0[(t2 >> 8) & 255], 24) ^ Shift(Tinv0[(t1 >> 16) & 255], 16) ^ Shift(Tinv0[(t0 >> 24) & 255], 8) ^ kw[3];

            // the final round's table is a simple function of Si so we don't use a whole other four tables for it

            kw = KW[0];
            C0 = (uint)Si[r0 & 255] ^ (((uint)s[(r3 >> 8) & 255]) << 8) ^ (((uint)s[(r2 >> 16) & 255]) << 16) ^ (((uint)Si[(r1 >> 24) & 255]) << 24) ^ kw[0];
            C1 = (uint)s[r1 & 255] ^ (((uint)s[(r0 >> 8) & 255]) << 8) ^ (((uint)Si[(r3 >> 16) & 255]) << 16) ^ (((uint)s[(r2 >> 24) & 255]) << 24) ^ kw[1];
            C2 = (uint)s[r2 & 255] ^ (((uint)Si[(r1 >> 8) & 255]) << 8) ^ (((uint)Si[(r0 >> 16) & 255]) << 16) ^ (((uint)s[(r3 >> 24) & 255]) << 24) ^ kw[2];
            C3 = (uint)Si[r3 & 255] ^ (((uint)s[(r2 >> 8) & 255]) << 8) ^ (((uint)s[(r1 >> 16) & 255]) << 16) ^ (((uint)s[(r0 >> 24) & 255]) << 24) ^ kw[3];

            Pack.UInt32_To_LE(C0, output);
            Pack.UInt32_To_LE(C1, output[4..]);
            Pack.UInt32_To_LE(C2, output[8..]);
            Pack.UInt32_To_LE(C3, output[12..]);
        }
#else
        private void EncryptBlock(byte[] input, int inOff, byte[] output, int outOff, uint[][] KW)
        {
            FastAesEngineHelper.EncryptBlock(input, inOff, output, outOff, KW, ROUNDS, T0, S, s);
            //uint C0 = Pack.LE_To_UInt32(input, inOff + 0);
            //uint C1 = Pack.LE_To_UInt32(input, inOff + 4);
            //uint C2 = Pack.LE_To_UInt32(input, inOff + 8);
            //uint C3 = Pack.LE_To_UInt32(input, inOff + 12);
            //
            //uint[] kw = KW[0];
            //uint t0 = C0 ^ kw[0];
            //uint t1 = C1 ^ kw[1];
            //uint t2 = C2 ^ kw[2];
            //
            //uint r0, r1, r2, r3 = C3 ^ kw[3];
            //int r = 1;
            //while (r < ROUNDS - 1)
            //{
            //    kw = KW[r++];
            //    r0 = T0[t0 & 255] ^ Shift(T0[(t1 >> 8) & 255], 24) ^ Shift(T0[(t2 >> 16) & 255], 16) ^ Shift(T0[(r3 >> 24) & 255], 8) ^ kw[0];
            //    r1 = T0[t1 & 255] ^ Shift(T0[(t2 >> 8) & 255], 24) ^ Shift(T0[(r3 >> 16) & 255], 16) ^ Shift(T0[(t0 >> 24) & 255], 8) ^ kw[1];
            //    r2 = T0[t2 & 255] ^ Shift(T0[(r3 >> 8) & 255], 24) ^ Shift(T0[(t0 >> 16) & 255], 16) ^ Shift(T0[(t1 >> 24) & 255], 8) ^ kw[2];
            //    r3 = T0[r3 & 255] ^ Shift(T0[(t0 >> 8) & 255], 24) ^ Shift(T0[(t1 >> 16) & 255], 16) ^ Shift(T0[(t2 >> 24) & 255], 8) ^ kw[3];
            //    kw = KW[r++];
            //    t0 = T0[r0 & 255] ^ Shift(T0[(r1 >> 8) & 255], 24) ^ Shift(T0[(r2 >> 16) & 255], 16) ^ Shift(T0[(r3 >> 24) & 255], 8) ^ kw[0];
            //    t1 = T0[r1 & 255] ^ Shift(T0[(r2 >> 8) & 255], 24) ^ Shift(T0[(r3 >> 16) & 255], 16) ^ Shift(T0[(r0 >> 24) & 255], 8) ^ kw[1];
            //    t2 = T0[r2 & 255] ^ Shift(T0[(r3 >> 8) & 255], 24) ^ Shift(T0[(r0 >> 16) & 255], 16) ^ Shift(T0[(r1 >> 24) & 255], 8) ^ kw[2];
            //    r3 = T0[r3 & 255] ^ Shift(T0[(r0 >> 8) & 255], 24) ^ Shift(T0[(r1 >> 16) & 255], 16) ^ Shift(T0[(r2 >> 24) & 255], 8) ^ kw[3];
            //}
            //
            //kw = KW[r++];
            //r0 = T0[t0 & 255] ^ Shift(T0[(t1 >> 8) & 255], 24) ^ Shift(T0[(t2 >> 16) & 255], 16) ^ Shift(T0[(r3 >> 24) & 255], 8) ^ kw[0];
            //r1 = T0[t1 & 255] ^ Shift(T0[(t2 >> 8) & 255], 24) ^ Shift(T0[(r3 >> 16) & 255], 16) ^ Shift(T0[(t0 >> 24) & 255], 8) ^ kw[1];
            //r2 = T0[t2 & 255] ^ Shift(T0[(r3 >> 8) & 255], 24) ^ Shift(T0[(t0 >> 16) & 255], 16) ^ Shift(T0[(t1 >> 24) & 255], 8) ^ kw[2];
            //r3 = T0[r3 & 255] ^ Shift(T0[(t0 >> 8) & 255], 24) ^ Shift(T0[(t1 >> 16) & 255], 16) ^ Shift(T0[(t2 >> 24) & 255], 8) ^ kw[3];
            //
            //// the final round's table is a simple function of S so we don't use a whole other four tables for it
            //
            //kw = KW[r];
            //C0 = (uint)S[r0 & 255] ^ (((uint)S[(r1 >> 8) & 255]) << 8) ^ (((uint)s[(r2 >> 16) & 255]) << 16) ^ (((uint)s[(r3 >> 24) & 255]) << 24) ^ kw[0];
            //C1 = (uint)s[r1 & 255] ^ (((uint)S[(r2 >> 8) & 255]) << 8) ^ (((uint)S[(r3 >> 16) & 255]) << 16) ^ (((uint)s[(r0 >> 24) & 255]) << 24) ^ kw[1];
            //C2 = (uint)s[r2 & 255] ^ (((uint)S[(r3 >> 8) & 255]) << 8) ^ (((uint)S[(r0 >> 16) & 255]) << 16) ^ (((uint)S[(r1 >> 24) & 255]) << 24) ^ kw[2];
            //C3 = (uint)s[r3 & 255] ^ (((uint)s[(r0 >> 8) & 255]) << 8) ^ (((uint)s[(r1 >> 16) & 255]) << 16) ^ (((uint)S[(r2 >> 24) & 255]) << 24) ^ kw[3];
            //
            //Pack.UInt32_To_LE(C0, output, outOff + 0);
            //Pack.UInt32_To_LE(C1, output, outOff + 4);
            //Pack.UInt32_To_LE(C2, output, outOff + 8);
            //Pack.UInt32_To_LE(C3, output, outOff + 12);
        }

        private void DecryptBlock(byte[] input, int inOff, byte[] output, int outOff, uint[][] KW)
        {
            uint C0 = Pack.LE_To_UInt32(input, inOff + 0);
            uint C1 = Pack.LE_To_UInt32(input, inOff + 4);
            uint C2 = Pack.LE_To_UInt32(input, inOff + 8);
            uint C3 = Pack.LE_To_UInt32(input, inOff + 12);

            uint[] kw = KW[ROUNDS];
            uint t0 = C0 ^ kw[0];
            uint t1 = C1 ^ kw[1];
            uint t2 = C2 ^ kw[2];

            uint r0, r1, r2, r3 = C3 ^ kw[3];
            int r = ROUNDS - 1;
            while (r > 1)
            {
                kw = KW[r--];
                r0 = Tinv0[t0 & 255] ^ Shift(Tinv0[(r3 >> 8) & 255], 24) ^ Shift(Tinv0[(t2 >> 16) & 255], 16) ^ Shift(Tinv0[(t1 >> 24) & 255], 8) ^ kw[0];
                r1 = Tinv0[t1 & 255] ^ Shift(Tinv0[(t0 >> 8) & 255], 24) ^ Shift(Tinv0[(r3 >> 16) & 255], 16) ^ Shift(Tinv0[(t2 >> 24) & 255], 8) ^ kw[1];
                r2 = Tinv0[t2 & 255] ^ Shift(Tinv0[(t1 >> 8) & 255], 24) ^ Shift(Tinv0[(t0 >> 16) & 255], 16) ^ Shift(Tinv0[(r3 >> 24) & 255], 8) ^ kw[2];
                r3 = Tinv0[r3 & 255] ^ Shift(Tinv0[(t2 >> 8) & 255], 24) ^ Shift(Tinv0[(t1 >> 16) & 255], 16) ^ Shift(Tinv0[(t0 >> 24) & 255], 8) ^ kw[3];
                kw = KW[r--];
                t0 = Tinv0[r0 & 255] ^ Shift(Tinv0[(r3 >> 8) & 255], 24) ^ Shift(Tinv0[(r2 >> 16) & 255], 16) ^ Shift(Tinv0[(r1 >> 24) & 255], 8) ^ kw[0];
                t1 = Tinv0[r1 & 255] ^ Shift(Tinv0[(r0 >> 8) & 255], 24) ^ Shift(Tinv0[(r3 >> 16) & 255], 16) ^ Shift(Tinv0[(r2 >> 24) & 255], 8) ^ kw[1];
                t2 = Tinv0[r2 & 255] ^ Shift(Tinv0[(r1 >> 8) & 255], 24) ^ Shift(Tinv0[(r0 >> 16) & 255], 16) ^ Shift(Tinv0[(r3 >> 24) & 255], 8) ^ kw[2];
                r3 = Tinv0[r3 & 255] ^ Shift(Tinv0[(r2 >> 8) & 255], 24) ^ Shift(Tinv0[(r1 >> 16) & 255], 16) ^ Shift(Tinv0[(r0 >> 24) & 255], 8) ^ kw[3];
            }

            kw = KW[1];
            r0 = Tinv0[t0 & 255] ^ Shift(Tinv0[(r3 >> 8) & 255], 24) ^ Shift(Tinv0[(t2 >> 16) & 255], 16) ^ Shift(Tinv0[(t1 >> 24) & 255], 8) ^ kw[0];
            r1 = Tinv0[t1 & 255] ^ Shift(Tinv0[(t0 >> 8) & 255], 24) ^ Shift(Tinv0[(r3 >> 16) & 255], 16) ^ Shift(Tinv0[(t2 >> 24) & 255], 8) ^ kw[1];
            r2 = Tinv0[t2 & 255] ^ Shift(Tinv0[(t1 >> 8) & 255], 24) ^ Shift(Tinv0[(t0 >> 16) & 255], 16) ^ Shift(Tinv0[(r3 >> 24) & 255], 8) ^ kw[2];
            r3 = Tinv0[r3 & 255] ^ Shift(Tinv0[(t2 >> 8) & 255], 24) ^ Shift(Tinv0[(t1 >> 16) & 255], 16) ^ Shift(Tinv0[(t0 >> 24) & 255], 8) ^ kw[3];

            // the final round's table is a simple function of Si so we don't use a whole other four tables for it

            kw = KW[0];
            C0 = (uint)Si[r0 & 255] ^ (((uint)s[(r3 >> 8) & 255]) << 8) ^ (((uint)s[(r2 >> 16) & 255]) << 16) ^ (((uint)Si[(r1 >> 24) & 255]) << 24) ^ kw[0];
            C1 = (uint)s[r1 & 255] ^ (((uint)s[(r0 >> 8) & 255]) << 8) ^ (((uint)Si[(r3 >> 16) & 255]) << 16) ^ (((uint)s[(r2 >> 24) & 255]) << 24) ^ kw[1];
            C2 = (uint)s[r2 & 255] ^ (((uint)Si[(r1 >> 8) & 255]) << 8) ^ (((uint)Si[(r0 >> 16) & 255]) << 16) ^ (((uint)s[(r3 >> 24) & 255]) << 24) ^ kw[2];
            C3 = (uint)Si[r3 & 255] ^ (((uint)s[(r2 >> 8) & 255]) << 8) ^ (((uint)s[(r1 >> 16) & 255]) << 16) ^ (((uint)s[(r0 >> 24) & 255]) << 24) ^ kw[3];

            Pack.UInt32_To_LE(C0, output, outOff + 0);
            Pack.UInt32_To_LE(C1, output, outOff + 4);
            Pack.UInt32_To_LE(C2, output, outOff + 8);
            Pack.UInt32_To_LE(C3, output, outOff + 12);
        }
#endif
    }
}
#pragma warning restore
#endif