miracl_core_bls12381 4.2.2

Rust code of https://github.com/miracl/core (miracl_core) for curve BLS 12-381
Documentation 
/*
 * Copyright (c) 2012-2020 MIRACL UK Ltd.
 *
 * This file is part of MIRACL Core
 * (see https://github.com/miracl/core).
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

pub const ECB: usize = 0;
pub const CBC: usize = 1;
pub const CFB1: usize = 2;
pub const CFB2: usize = 3;
pub const CFB4: usize = 5;
pub const OFB1: usize = 14;
pub const OFB2: usize = 15;
pub const OFB4: usize = 17;
pub const OFB8: usize = 21;
pub const OFB16: usize = 29;
pub const CTR1: usize = 30;
pub const CTR2: usize = 31;
pub const CTR4: usize = 33;
pub const CTR8: usize = 37;
pub const CTR16: usize = 45;

const INCO: [u8; 4] = [0xB, 0xD, 0x9, 0xE]; /* Inverse Coefficients */

const PTAB: [u8; 256] = [
    1, 3, 5, 15, 17, 51, 85, 255, 26, 46, 114, 150, 161, 248, 19, 53, 95, 225, 56, 72, 216, 115,
    149, 164, 247, 2, 6, 10, 30, 34, 102, 170, 229, 52, 92, 228, 55, 89, 235, 38, 106, 190, 217,
    112, 144, 171, 230, 49, 83, 245, 4, 12, 20, 60, 68, 204, 79, 209, 104, 184, 211, 110, 178, 205,
    76, 212, 103, 169, 224, 59, 77, 215, 98, 166, 241, 8, 24, 40, 120, 136, 131, 158, 185, 208,
    107, 189, 220, 127, 129, 152, 179, 206, 73, 219, 118, 154, 181, 196, 87, 249, 16, 48, 80, 240,
    11, 29, 39, 105, 187, 214, 97, 163, 254, 25, 43, 125, 135, 146, 173, 236, 47, 113, 147, 174,
    233, 32, 96, 160, 251, 22, 58, 78, 210, 109, 183, 194, 93, 231, 50, 86, 250, 21, 63, 65, 195,
    94, 226, 61, 71, 201, 64, 192, 91, 237, 44, 116, 156, 191, 218, 117, 159, 186, 213, 100, 172,
    239, 42, 126, 130, 157, 188, 223, 122, 142, 137, 128, 155, 182, 193, 88, 232, 35, 101, 175,
    234, 37, 111, 177, 200, 67, 197, 84, 252, 31, 33, 99, 165, 244, 7, 9, 27, 45, 119, 153, 176,
    203, 70, 202, 69, 207, 74, 222, 121, 139, 134, 145, 168, 227, 62, 66, 198, 81, 243, 14, 18, 54,
    90, 238, 41, 123, 141, 140, 143, 138, 133, 148, 167, 242, 13, 23, 57, 75, 221, 124, 132, 151,
    162, 253, 28, 36, 108, 180, 199, 82, 246, 1,
];

const LTAB: [u8; 256] = [
    0, 255, 25, 1, 50, 2, 26, 198, 75, 199, 27, 104, 51, 238, 223, 3, 100, 4, 224, 14, 52, 141,
    129, 239, 76, 113, 8, 200, 248, 105, 28, 193, 125, 194, 29, 181, 249, 185, 39, 106, 77, 228,
    166, 114, 154, 201, 9, 120, 101, 47, 138, 5, 33, 15, 225, 36, 18, 240, 130, 69, 53, 147, 218,
    142, 150, 143, 219, 189, 54, 208, 206, 148, 19, 92, 210, 241, 64, 70, 131, 56, 102, 221, 253,
    48, 191, 6, 139, 98, 179, 37, 226, 152, 34, 136, 145, 16, 126, 110, 72, 195, 163, 182, 30, 66,
    58, 107, 40, 84, 250, 133, 61, 186, 43, 121, 10, 21, 155, 159, 94, 202, 78, 212, 172, 229, 243,
    115, 167, 87, 175, 88, 168, 80, 244, 234, 214, 116, 79, 174, 233, 213, 231, 230, 173, 232, 44,
    215, 117, 122, 235, 22, 11, 245, 89, 203, 95, 176, 156, 169, 81, 160, 127, 12, 246, 111, 23,
    196, 73, 236, 216, 67, 31, 45, 164, 118, 123, 183, 204, 187, 62, 90, 251, 96, 177, 134, 59, 82,
    161, 108, 170, 85, 41, 157, 151, 178, 135, 144, 97, 190, 220, 252, 188, 149, 207, 205, 55, 63,
    91, 209, 83, 57, 132, 60, 65, 162, 109, 71, 20, 42, 158, 93, 86, 242, 211, 171, 68, 17, 146,
    217, 35, 32, 46, 137, 180, 124, 184, 38, 119, 153, 227, 165, 103, 74, 237, 222, 197, 49, 254,
    24, 13, 99, 140, 128, 192, 247, 112, 7,
];

const FBSUB: [u8; 256] = [
    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,
];

const RBSUB: [u8; 256] = [
    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,
];

const RCO: [u8; 16] = [
    1, 2, 4, 8, 16, 32, 64, 128, 27, 54, 108, 216, 171, 77, 154, 47,
];

const FTABLE: [u32; 256] = [
    0xa56363c6, 0x847c7cf8, 0x997777ee, 0x8d7b7bf6, 0xdf2f2ff, 0xbd6b6bd6, 0xb16f6fde, 0x54c5c591,
    0x50303060, 0x3010102, 0xa96767ce, 0x7d2b2b56, 0x19fefee7, 0x62d7d7b5, 0xe6abab4d, 0x9a7676ec,
    0x45caca8f, 0x9d82821f, 0x40c9c989, 0x877d7dfa, 0x15fafaef, 0xeb5959b2, 0xc947478e, 0xbf0f0fb,
    0xecadad41, 0x67d4d4b3, 0xfda2a25f, 0xeaafaf45, 0xbf9c9c23, 0xf7a4a453, 0x967272e4, 0x5bc0c09b,
    0xc2b7b775, 0x1cfdfde1, 0xae93933d, 0x6a26264c, 0x5a36366c, 0x413f3f7e, 0x2f7f7f5, 0x4fcccc83,
    0x5c343468, 0xf4a5a551, 0x34e5e5d1, 0x8f1f1f9, 0x937171e2, 0x73d8d8ab, 0x53313162, 0x3f15152a,
    0xc040408, 0x52c7c795, 0x65232346, 0x5ec3c39d, 0x28181830, 0xa1969637, 0xf05050a, 0xb59a9a2f,
    0x907070e, 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, 0x0, 0x2cededc1, 0x60202040, 0x1ffcfce3, 0xc8b1b179, 0xed5b5bb6,
    0xbe6a6ad4, 0x46cbcb8d, 0xd9bebe67, 0x4b393972, 0xde4a4a94, 0xd44c4c98, 0xe85858b0, 0x4acfcf85,
    0x6bd0d0bb, 0x2aefefc5, 0xe5aaaa4f, 0x16fbfbed, 0xc5434386, 0xd74d4d9a, 0x55333366, 0x94858511,
    0xcf45458a, 0x10f9f9e9, 0x6020204, 0x817f7ffe, 0xf05050a0, 0x443c3c78, 0xba9f9f25, 0xe3a8a84b,
    0xf35151a2, 0xfea3a35d, 0xc0404080, 0x8a8f8f05, 0xad92923f, 0xbc9d9d21, 0x48383870, 0x4f5f5f1,
    0xdfbcbc63, 0xc1b6b677, 0x75dadaaf, 0x63212142, 0x30101020, 0x1affffe5, 0xef3f3fd, 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, 0xa06060c, 0x6c242448, 0xe45c5cb8,
    0x5dc2c29f, 0x6ed3d3bd, 0xefacac43, 0xa66262c4, 0xa8919139, 0xa4959531, 0x37e4e4d3, 0x8b7979f2,
    0x32e7e7d5, 0x43c8c88b, 0x5937376e, 0xb76d6dda, 0x8c8d8d01, 0x64d5d5b1, 0xd24e4e9c, 0xe0a9a949,
    0xb46c6cd8, 0xfa5656ac, 0x7f4f4f3, 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, 0x5030306, 0x1f6f6f7, 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,
];

const RTABLE: [u32; 256] = [
    0x50a7f451, 0x5365417e, 0xc3a4171a, 0x965e273a, 0xcb6bab3b, 0xf1459d1f, 0xab58faac, 0x9303e34b,
    0x55fa3020, 0xf66d76ad, 0x9176cc88, 0x254c02f5, 0xfcd7e54f, 0xd7cb2ac5, 0x80443526, 0x8fa362b5,
    0x495ab1de, 0x671bba25, 0x980eea45, 0xe1c0fe5d, 0x2752fc3, 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,
    0x728ebb2, 0x3c2b52f, 0x9a7bc586, 0xa50837d3, 0xf2872830, 0xb2a5bf23, 0xba6a0302, 0x5c8216ed,
    0x2b1ccf8a, 0x92b479a7, 0xf0f207f3, 0xa1e2694e, 0xcdf4da65, 0xd5be0506, 0x1f6234d1, 0x8afea6c4,
    0x9d532e34, 0xa055f3a2, 0x32e18a05, 0x75ebf6a4, 0x39ec830b, 0xaaef6040, 0x69f715e, 0x51106ebd,
    0xf98a213e, 0x3d06dd96, 0xae053edd, 0x46bde64d, 0xb58d5491, 0x55dc471, 0x6fd40604, 0xff155060,
    0x24fb9819, 0x97e9bdd6, 0xcc434089, 0x779ed967, 0xbd42e8b0, 0x888b8907, 0x385b19e7, 0xdbeec879,
    0x470a7ca1, 0xe90f427c, 0xc91e84f8, 0x0, 0x83868009, 0x48ed2b32, 0xac70111e, 0x4e725a6c,
    0xfbff0efd, 0x5638850f, 0x1ed5ae3d, 0x27392d36, 0x64d90f0a, 0x21a65c68, 0xd1545b9b, 0x3a2e3624,
    0xb1670a0c, 0xfe75793, 0xd296eeb4, 0x9e919b1b, 0x4fc5c080, 0xa220dc61, 0x694b775a, 0x161a121c,
    0xaba93e2, 0xe52aa0c0, 0x43e0223c, 0x1d171b12, 0xb0d090e, 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, 0xd927850, 0x9bcc5f6a, 0x62467e54, 0xc2138df6, 0xe8b8d890, 0x5ef7392e, 0xf5afc382,
    0xbe805d9f, 0x7c93d069, 0xa92dd56f, 0xb31225cf, 0x3b99acc8, 0xa77d1810, 0x6e639ce8, 0x7bbb3bdb,
    0x97826cd, 0xf418596e, 0x1b79aec, 0xa89a4f83, 0x656e95e6, 0x7ee6ffaa, 0x8cfbc21, 0xe6e815ef,
    0xd99be7ba, 0xce366f4a, 0xd4099fea, 0xd67cb029, 0xafb2a431, 0x31233f2a, 0x3094a5c6, 0xc066a235,
    0x37bc4e74, 0xa6ca82fc, 0xb0d090e0, 0x15d8a733, 0x4a9804f1, 0xf7daec41, 0xe50cd7f, 0x2ff69117,
    0x8dd64d76, 0x4db0ef43, 0x544daacc, 0xdf0496e4, 0xe3b5d19e, 0x1b886a4c, 0xb81f2cc1, 0x7f516546,
    0x4ea5e9d, 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, 0xc25e2bc, 0x8b493c28, 0x41950dff,
    0x7101a839, 0xdeb30c08, 0x9ce4b4d8, 0x90c15664, 0x6184cb7b, 0x70b632d5, 0x745c6c48, 0x4257b8d0,
];

pub struct AES {
//    nk: usize,
    nr: usize,
    mode: usize,
    fkey: [u32; 60],
    rkey: [u32; 60],
    pub f: [u8; 16],
}


fn rotl8(x: u32) -> u32 {
    ((x) << 8) | ((x) >> 24)
}

fn rotl16(x: u32) -> u32 {
    ((x) << 16) | ((x) >> 16)
}

fn rotl24(x: u32) -> u32 {
    ((x) << 24) | ((x) >> 8)
}

fn pack(b: [u8; 4]) -> u32 {
    /* pack bytes into a 32-bit Word */
    ((b[3] as u32) << 24)
        | ((b[2] as u32) << 16)
        | ((b[1] as u32) << 8)
        | (b[0] as u32)
}

fn unpack(a: u32) -> [u8; 4] {
    /* unpack bytes from a word */
    [
        (a & 0xff) as u8,
        ((a >> 8) & 0xff) as u8,
        ((a >> 16) & 0xff) as u8,
        ((a >> 24) & 0xff) as u8,
    ]
}

fn bmul(x: u8, y: u8) -> u8 {
    /* x.y= AntiLog(Log(x) + Log(y)) */
    let ix = (x as usize) & 0xff;
    let iy = (y as usize) & 0xff;
    let lx = (LTAB[ix] as usize) & 0xff;
    let ly = (LTAB[iy] as usize) & 0xff;

    if x != 0 && y != 0 {
        PTAB[(lx + ly) % 255]
    } else {
        0
    }
}

fn subbyte(a: u32) -> u32 {
    let mut b = unpack(a);
    b[0] = FBSUB[b[0] as usize];
    b[1] = FBSUB[b[1] as usize];
    b[2] = FBSUB[b[2] as usize];
    b[3] = FBSUB[b[3] as usize];
    pack(b)
}

fn product(x: u32, y: u32) -> u8 {
    /* dot product of two 4-byte arrays */
    let xb = unpack(x);
    let yb = unpack(y);

    bmul(xb[0], yb[0])
        ^ bmul(xb[1], yb[1])
        ^ bmul(xb[2], yb[2])
        ^ bmul(xb[3], yb[3])
}

fn invmixcol(x: u32) -> u32 {
    /* matrix Multiplication */
    let mut b: [u8; 4] = [0; 4];
    let mut m = pack(INCO);
    b[3] = product(m, x);
    m = rotl24(m);
    b[2] = product(m, x);
    m = rotl24(m);
    b[1] = product(m, x);
    m = rotl24(m);
    b[0] = product(m, x);
    pack(b)
}

fn increment(f: &mut [u8; 16]) {
    for i in 0..16 {
        f[i] += 1;
        if f[i] != 0 {
            break;
        }
    }
}

impl AES {

    pub fn new() -> AES {
        AES {
//            nk: 0,
            nr: 0,
            mode: 0,
            fkey: [0; 60],
            rkey: [0; 60],
            f: [0; 16],
        }
    }

    /* reset cipher */
    pub fn reset(&mut self, m: usize, iv: Option<[u8; 16]>) {
        /* reset mode, or reset iv */
        self.mode = m;
        for i in 0..16 {
            self.f[i] = 0
        }
        if self.mode != ECB {
            if let Some(x) = iv {
                for i in 0..16 {
                    self.f[i] = x[i]
                }
            }
        }
    }

    pub fn init(&mut self, m: usize, nkey: usize, key: &[u8], iv: Option<[u8; 16]>) -> bool {
        /* Key Scheduler. Create expanded encryption key */
        let mut cipherkey: [u32; 8] = [0; 8];
        let mut b: [u8; 4] = [0; 4];
        let nk = nkey / 4;
        if nk != 4 && nk != 6 && nk != 8 {
            return false;
        }
        let nr = 6 + nk;
        //self.nk = nk;
        self.nr = nr;
        self.reset(m, iv);
        let n = 4 * (nr + 1);

        let mut j = 0;
        for i in 0..nk {
            for k in 0..4 {
                b[k] = key[j + k]
            }
            cipherkey[i] = pack(b);
            j += 4;
        }

        for i in 0..nk {
            self.fkey[i] = cipherkey[i]
        }

        j = nk;
        let mut k = 0;
        while j < n {
            self.fkey[j] =
                self.fkey[j - nk] ^ subbyte(rotl24(self.fkey[j - 1])) ^ (RCO[k] as u32);
            if nk<=6 { 
		for i in 1..nk {
			if (i + j) >= n {
				break;
			}
			self.fkey[i + j] = self.fkey[i + j - nk] ^ self.fkey[i + j - 1];
		}
	    } else {
		for i in 1..4  {
			if (i + j) >= n {
				break;
			}
			self.fkey[i + j] = self.fkey[i + j - nk] ^ self.fkey[i + j - 1];
		}
		
		if (j + 4) < n {
			self.fkey[j + 4] = self.fkey[j + 4 - nk] ^ subbyte(self.fkey[j + 3]);
		}
		for i in 5..nk {
			if (i + j) >= n {
				break;
			}
			self.fkey[i + j] = self.fkey[i + j - nk] ^ self.fkey[i + j - 1];
		}	        
	    }
            j += nk;
            k += 1;
        }

        /* now for the expanded decrypt key in reverse order */

        for j in 0..4 {
            self.rkey[j + n - 4] = self.fkey[j]
        }
        let mut i = 4;
        while i < n - 4 {
            let k = n - 4 - i;
            for j in 0..4 {
                self.rkey[k + j] = invmixcol(self.fkey[i + j])
            }
            i += 4;
        }
        for j in n - 4..n {
            self.rkey[j + 4 - n] = self.fkey[j]
        }
        true
    }

    pub fn getreg(&mut self) -> [u8; 16] {
        let mut ir: [u8; 16] = [0; 16];
        for i in 0..16 {
            ir[i] = self.f[i]
        }
        ir
    }

    /* Encrypt a single block */
    pub fn ecb_encrypt(&mut self, buff: &mut [u8; 16]) {
        let mut b: [u8; 4] = [0; 4];
        let mut p: [u32; 4] = [0; 4];
        let mut q: [u32; 4] = [0; 4];

        let mut j = 0;
        for i in 0..4 {
            for k in 0..4 {
                b[k] = buff[j + k]
            }
            p[i] = pack(b);
            p[i] ^= self.fkey[i];
            j += 4;
        }

        let mut k = 4;

        /* State alternates between p and q */
        for _ in 1..self.nr {
            q[0] = self.fkey[k]
                ^ FTABLE[(p[0] & 0xff) as usize]
                ^ rotl8(FTABLE[((p[1] >> 8) & 0xff) as usize])
                ^ rotl16(FTABLE[((p[2] >> 16) & 0xff) as usize])
                ^ rotl24(FTABLE[((p[3] >> 24) & 0xff) as usize]);

            q[1] = self.fkey[k + 1]
                ^ FTABLE[(p[1] & 0xff) as usize]
                ^ rotl8(FTABLE[((p[2] >> 8) & 0xff) as usize])
                ^ rotl16(FTABLE[((p[3] >> 16) & 0xff) as usize])
                ^ rotl24(FTABLE[((p[0] >> 24) & 0xff) as usize]);

            q[2] = self.fkey[k + 2]
                ^ FTABLE[(p[2] & 0xff) as usize]
                ^ rotl8(FTABLE[((p[3] >> 8) & 0xff) as usize])
                ^ rotl16(FTABLE[((p[0] >> 16) & 0xff) as usize])
                ^ rotl24(FTABLE[((p[1] >> 24) & 0xff) as usize]);

            q[3] = self.fkey[k + 3]
                ^ FTABLE[(p[3] & 0xff) as usize]
                ^ rotl8(FTABLE[((p[0] >> 8) & 0xff) as usize])
                ^ rotl16(FTABLE[((p[1] >> 16) & 0xff) as usize])
                ^ rotl24(FTABLE[((p[2] >> 24) & 0xff) as usize]);

            k += 4;
            for j in 0..4 {
                let t = p[j];
                p[j] = q[j];
                q[j] = t;
            }
        }

        /* Last Round */

        q[0] = self.fkey[k]
            ^ (FBSUB[(p[0] & 0xff) as usize] as u32)
            ^ rotl8((FBSUB[((p[1] >> 8) & 0xff) as usize]) as u32)
            ^ rotl16((FBSUB[((p[2] >> 16) & 0xff) as usize]) as u32)
            ^ rotl24((FBSUB[((p[3] >> 24) & 0xff) as usize]) as u32);

        q[1] = self.fkey[k + 1]
            ^ (FBSUB[(p[1] & 0xff) as usize] as u32)
            ^ rotl8((FBSUB[((p[2] >> 8) & 0xff) as usize]) as u32)
            ^ rotl16((FBSUB[((p[3] >> 16) & 0xff) as usize]) as u32)
            ^ rotl24((FBSUB[((p[0] >> 24) & 0xff) as usize]) as u32);

        q[2] = self.fkey[k + 2]
            ^ (FBSUB[(p[2] & 0xff) as usize] as u32)
            ^ rotl8((FBSUB[((p[3] >> 8) & 0xff) as usize]) as u32)
            ^ rotl16((FBSUB[((p[0] >> 16) & 0xff) as usize]) as u32)
            ^ rotl24((FBSUB[((p[1] >> 24) & 0xff) as usize]) as u32);

        q[3] = self.fkey[k + 3]
            ^ (FBSUB[(p[3] & 0xff) as usize] as u32)
            ^ rotl8((FBSUB[((p[0] >> 8) & 0xff) as usize]) as u32)
            ^ rotl16((FBSUB[((p[1] >> 16) & 0xff) as usize]) as u32)
            ^ rotl24((FBSUB[((p[2] >> 24) & 0xff) as usize]) as u32);

        j = 0;
        for i in 0..4 {
            b = unpack(q[i]);
            for k in 0..4 {
                buff[j + k] = b[k]
            }
            j += 4;
        }
    }

    /* Decrypt a single block */
    pub fn ecb_decrypt(&mut self, buff: &mut [u8; 16]) {
        let mut b: [u8; 4] = [0; 4];
        let mut p: [u32; 4] = [0; 4];
        let mut q: [u32; 4] = [0; 4];

        let mut j = 0;
        for i in 0..4 {
            for k in 0..4 {
                b[k] = buff[j + k]
            }
            p[i] = pack(b);
            p[i] ^= self.rkey[i];
            j += 4;
        }

        let mut k = 4;

        /* State alternates between p and q */
        for _ in 1..self.nr {
            q[0] = self.rkey[k]
                ^ RTABLE[(p[0] & 0xff) as usize]
                ^ rotl8(RTABLE[((p[3] >> 8) & 0xff) as usize])
                ^ rotl16(RTABLE[((p[2] >> 16) & 0xff) as usize])
                ^ rotl24(RTABLE[((p[1] >> 24) & 0xff) as usize]);

            q[1] = self.rkey[k + 1]
                ^ RTABLE[(p[1] & 0xff) as usize]
                ^ rotl8(RTABLE[((p[0] >> 8) & 0xff) as usize])
                ^ rotl16(RTABLE[((p[3] >> 16) & 0xff) as usize])
                ^ rotl24(RTABLE[((p[2] >> 24) & 0xff) as usize]);

            q[2] = self.rkey[k + 2]
                ^ RTABLE[(p[2] & 0xff) as usize]
                ^ rotl8(RTABLE[((p[1] >> 8) & 0xff) as usize])
                ^ rotl16(RTABLE[((p[0] >> 16) & 0xff) as usize])
                ^ rotl24(RTABLE[((p[3] >> 24) & 0xff) as usize]);

            q[3] = self.rkey[k + 3]
                ^ RTABLE[(p[3] & 0xff) as usize]
                ^ rotl8(RTABLE[((p[2] >> 8) & 0xff) as usize])
                ^ rotl16(RTABLE[((p[1] >> 16) & 0xff) as usize])
                ^ rotl24(RTABLE[((p[0] >> 24) & 0xff) as usize]);

            k += 4;
            for j in 0..4 {
                let t = p[j];
                p[j] = q[j];
                q[j] = t;
            }
        }

        /* Last Round */

        q[0] = self.rkey[k]
            ^ (RBSUB[(p[0] & 0xff) as usize] as u32)
            ^ rotl8((RBSUB[((p[3] >> 8) & 0xff) as usize]) as u32)
            ^ rotl16((RBSUB[((p[2] >> 16) & 0xff) as usize]) as u32)
            ^ rotl24((RBSUB[((p[1] >> 24) & 0xff) as usize]) as u32);

        q[1] = self.rkey[k + 1]
            ^ (RBSUB[(p[1] & 0xff) as usize] as u32)
            ^ rotl8((RBSUB[((p[0] >> 8) & 0xff) as usize]) as u32)
            ^ rotl16((RBSUB[((p[3] >> 16) & 0xff) as usize]) as u32)
            ^ rotl24((RBSUB[((p[2] >> 24) & 0xff) as usize]) as u32);

        q[2] = self.rkey[k + 2]
            ^ (RBSUB[(p[2] & 0xff) as usize] as u32)
            ^ rotl8((RBSUB[((p[1] >> 8) & 0xff) as usize]) as u32)
            ^ rotl16((RBSUB[((p[0] >> 16) & 0xff) as usize]) as u32)
            ^ rotl24((RBSUB[((p[3] >> 24) & 0xff) as usize]) as u32);

        q[3] = self.rkey[k + 3]
            ^ (RBSUB[((p[3]) & 0xff) as usize] as u32)
            ^ rotl8((RBSUB[((p[2] >> 8) & 0xff) as usize]) as u32)
            ^ rotl16((RBSUB[((p[1] >> 16) & 0xff) as usize]) as u32)
            ^ rotl24((RBSUB[((p[0] >> 24) & 0xff) as usize]) as u32);

        j = 0;
        for i in 0..4 {
            b = unpack(q[i]);
            for k in 0..4 {
                buff[j + k] = b[k]
            }
            j += 4;
        }
    }

    /* Encrypt using selected mode of operation */
    pub fn encrypt(&mut self, buff: &mut [u8; 16]) -> u32 {
        let mut st: [u8; 16] = [0; 16];

        // Supported Modes of Operation

        let mut fell_off: u32 = 0;

        match self.mode {
            ECB => {
                self.ecb_encrypt(buff);
                0
            }
            CBC => {
                for j in 0..16 {
                    buff[j] ^= self.f[j]
                }
                self.ecb_encrypt(buff);
                for j in 0..16 {
                    self.f[j] = buff[j]
                }
                0
            }

            CFB1 | CFB2 | CFB4 => {
                let bytes = self.mode - CFB1 + 1;
                for j in 0..bytes {
                    fell_off = (fell_off << 8) | (self.f[j] as u32)
                }
                for j in 0..16 {
                    st[j] = self.f[j]
                }
                for j in bytes..16 {
                    self.f[j - bytes] = self.f[j]
                }
                self.ecb_encrypt(&mut st);
                for j in 0..bytes {
                    buff[j] ^= st[j];
                    self.f[16 - bytes + j] = buff[j];
                }
                fell_off
            }

            OFB1 | OFB2 | OFB4 | OFB8 | OFB16 => {
                let bytes = self.mode - OFB1 + 1;
                for j in 0..16 {
                    st[j] = self.f[j]
                }
                self.ecb_encrypt(&mut st);
                for j in 0..bytes {
                    buff[j] ^= st[j]
                }
                for j in 0..16 {
                    self.f[j] = st[j]
                }

                //self.ecb_encrypt(&mut (self.f));
                //for j in 0..bytes {buff[j]^=self.f[j]}
                0
            }

            CTR1 | CTR2 | CTR4 | CTR8 | CTR16 => {
                let bytes = self.mode - CTR1 + 1;
                for j in 0..16 {
                    st[j] = self.f[j]
                }
                self.ecb_encrypt(&mut st);
                for j in 0..bytes {
                    buff[j] ^= st[j]
                }
                increment(&mut (self.f));
                0
            }

            _ => {
                0
            }
        }
    }

    /* Decrypt using selected mode of operation */
    pub fn decrypt(&mut self, buff: &mut [u8; 16]) -> u32 {
        let mut st: [u8; 16] = [0; 16];

        // Supported Modes of Operation

        let mut fell_off: u32 = 0;

        match self.mode {
            ECB => {
                self.ecb_decrypt(buff);
                0
            }
            CBC => {
                for j in 0..16 {
                    st[j] = self.f[j];
                    self.f[j] = buff[j];
                }
                self.ecb_decrypt(buff);
                for j in 0..16 {
                    buff[j] ^= st[j];
                    st[j] = 0;
                }
                0
            }
            CFB1 | CFB2 | CFB4 => {
                let bytes = self.mode - CFB1 + 1;
                for j in 0..bytes {
                    fell_off = (fell_off << 8) | (self.f[j] as u32)
                }
                for j in 0..16 {
                    st[j] = self.f[j]
                }
                for j in bytes..16 {
                    self.f[j - bytes] = self.f[j]
                }
                self.ecb_encrypt(&mut st);
                for j in 0..bytes {
                    self.f[16 - bytes + j] = buff[j];
                    buff[j] ^= st[j];
                }
                fell_off
            }
            OFB1 | OFB2 | OFB4 | OFB8 | OFB16 => {
                let bytes = self.mode - OFB1 + 1;
                for j in 0..16 {
                    st[j] = self.f[j]
                }
                self.ecb_encrypt(&mut st);
                for j in 0..bytes {
                    buff[j] ^= st[j]
                }
                for j in 0..16 {
                    self.f[j] = st[j]
                }
                //  self.ecb_encrypt(A.f[:]);
                //  for j in 0..bytes {buff[j]^=self.f[j]}
                0
            }

            CTR1 | CTR2 | CTR4 | CTR8 | CTR16 => {
                let bytes = self.mode - CTR1 + 1;
                for j in 0..16 {
                    st[j] = self.f[j]
                }
                self.ecb_encrypt(&mut st);
                for j in 0..bytes {
                    buff[j] ^= st[j]
                }
                increment(&mut (self.f));
                0
            }

            _ => {
                0
            }
        }
    }

    /* Clean up and delete left-overs */
    pub fn end(&mut self) {
        // clean up
        for i in 0..4 * (self.nr + 1) {
            self.fkey[i] = 0;
            self.rkey[i] = 0
        }
        for i in 0..16 {
            self.f[i] = 0
        }
    }
}

/* AES encryption/decryption. Encrypt byte array m using key k and returns ciphertext c */
pub fn cbc_iv0_encrypt(k: &[u8], m: &[u8],c: &mut [u8]) -> usize {
    /* AES CBC encryption, with Null IV and key K */
    /* Input is from an octet string m, output is to an octet string c */
    /* Input is padded as necessary to make up a full final block */
    let mut a = AES::new();
    let mut fin = false;

    let mut buff: [u8; 16] = [0; 16];

    a.init(CBC, k.len(), k, None);

    let mut ipt = 0;
    let mut opt = 0;
    let mut i;
    loop {
        i = 0;
        while i < 16 {
            if ipt < m.len() {
                buff[i] = m[ipt];
                i += 1;
                ipt += 1;
            } else {
                fin = true;
                break;
            }
        }
        if fin {
            break;
        }
        a.encrypt(&mut buff);
        for j in 0..16 {
            if opt < c.len() {
                c[opt]=buff[j]; opt+=1;
            }
        }
    }

    /* last block, filled up to i-th index */

    let padlen = 16 - i;
    for j in i..16 {
        buff[j] = padlen as u8
    }

    a.encrypt(&mut buff);

    for j in 0..16 {
        if opt<c.len() {
            c[opt]=buff[j]; opt+=1;
        }
    }
    a.end();
    opt
}

/* returns plaintext if all consistent, else returns null string */
pub fn cbc_iv0_decrypt(k: &[u8], c: &[u8], m: &mut [u8]) -> usize {
    /* padding is removed */
    let mut a = AES::new();
    let mut fin = false;

    let mut buff: [u8; 16] = [0; 16];

    a.init(CBC, k.len(), k, None);

    let mut ipt = 0;
    let mut opt = 0;
    let mut i;

    if c.is_empty() {
        return 0;
    }
    let mut ch = c[ipt];
    ipt += 1;

    loop {
        i = 0;
        while i < 16 {
            buff[i] = ch;
            if ipt >= c.len() {
                fin = true;
                break;
            } else {
                ch = c[ipt];
                ipt += 1
            }
            i += 1;
        }
        a.decrypt(&mut buff);
        if fin {
            break;
        }
        for j in 0..16 {
            if opt<m.len() {
                m[opt]=buff[j]; opt+=1;
            }
        }
    }

    a.end();
    let mut bad = false;
    let padlen = buff[15] as usize;
    if i != 15 || padlen < 1 || padlen > 16 {
        bad = true
    }
    if padlen >= 2 && padlen <= 16 {
        for j in 16 - padlen..16 {
            if buff[j] != padlen as u8 {
                bad = true
            }
        }
    }

    if !bad {
        for i in 0..16 - padlen {
            if opt<m.len() {
                m[opt]=buff[i]; opt+=1;
            }
        }
    }

    if bad {
        0
    } else {
        opt
    }
}

/*
fn main()
{
    let mut key:[u8;32]=[0;32];
    let mut block:[u8;16]=[0;16];
    let mut iv: [u8;16] = [0;16];

    for i in 0..32 {key[i]=0}
    key[0]=1;
    for i in 0..16 {iv[i]=i as u8}
    for i in 0..16 {block[i]=i as u8}

    let mut aes=AES::new();
    aes.init(CTR16,32,&key,Some(iv));

    println!("Plain= ");
    for i in 0..16 {print!("{:02x} ",block[i])}
    println!("");

    aes.encrypt(&mut block);

    println!("Encrypt= ");
    for i in 0..16 {print!("{:02x} ",block[i])}
    println!("");

    aes.reset(CTR16,Some(iv));
    aes.decrypt(&mut block);

    println!("Decrypt= ");
    for i in 0..16 {print!("{:02x} ",block[i])}
    println!("");

    aes.end();
}
*/