/*

 * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>

 *

 * Permission is hereby granted, free of charge, to any person obtaining 

 * a copy of this software and associated documentation files (the

 * "Software"), to deal in the Software without restriction, including

 * without limitation the rights to use, copy, modify, merge, publish,

 * distribute, sublicense, and/or sell copies of the Software, and to

 * permit persons to whom the Software is furnished to do so, subject to

 * the following conditions:

 *

 * The above copyright notice and this permission notice shall be 

 * included in all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 

 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 

 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS

 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN

 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN

 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

 * SOFTWARE.

 */

#include "inner.h"

#define S   br_aes_S

static const uint32_t Ssm0[] = {

  0xC66363A5, 0xF87C7C84, 0xEE777799, 0xF67B7B8D, 0xFFF2F20D, 0xD66B6BBD,

  0xDE6F6FB1, 0x91C5C554, 0x60303050, 0x02010103, 0xCE6767A9, 0x562B2B7D,

  0xE7FEFE19, 0xB5D7D762, 0x4DABABE6, 0xEC76769A, 0x8FCACA45, 0x1F82829D,

  0x89C9C940, 0xFA7D7D87, 0xEFFAFA15, 0xB25959EB, 0x8E4747C9, 0xFBF0F00B,

  0x41ADADEC, 0xB3D4D467, 0x5FA2A2FD, 0x45AFAFEA, 0x239C9CBF, 0x53A4A4F7,

  0xE4727296, 0x9BC0C05B, 0x75B7B7C2, 0xE1FDFD1C, 0x3D9393AE, 0x4C26266A,

  0x6C36365A, 0x7E3F3F41, 0xF5F7F702, 0x83CCCC4F, 0x6834345C, 0x51A5A5F4,

  0xD1E5E534, 0xF9F1F108, 0xE2717193, 0xABD8D873, 0x62313153, 0x2A15153F,

  0x0804040C, 0x95C7C752, 0x46232365, 0x9DC3C35E, 0x30181828, 0x379696A1,

  0x0A05050F, 0x2F9A9AB5, 0x0E070709, 0x24121236, 0x1B80809B, 0xDFE2E23D,

  0xCDEBEB26, 0x4E272769, 0x7FB2B2CD, 0xEA75759F, 0x1209091B, 0x1D83839E,

  0x582C2C74, 0x341A1A2E, 0x361B1B2D, 0xDC6E6EB2, 0xB45A5AEE, 0x5BA0A0FB,

  0xA45252F6, 0x763B3B4D, 0xB7D6D661, 0x7DB3B3CE, 0x5229297B, 0xDDE3E33E,

  0x5E2F2F71, 0x13848497, 0xA65353F5, 0xB9D1D168, 0x00000000, 0xC1EDED2C,

  0x40202060, 0xE3FCFC1F, 0x79B1B1C8, 0xB65B5BED, 0xD46A6ABE, 0x8DCBCB46,

  0x67BEBED9, 0x7239394B, 0x944A4ADE, 0x984C4CD4, 0xB05858E8, 0x85CFCF4A,

  0xBBD0D06B, 0xC5EFEF2A, 0x4FAAAAE5, 0xEDFBFB16, 0x864343C5, 0x9A4D4DD7,

  0x66333355, 0x11858594, 0x8A4545CF, 0xE9F9F910, 0x04020206, 0xFE7F7F81,

  0xA05050F0, 0x783C3C44, 0x259F9FBA, 0x4BA8A8E3, 0xA25151F3, 0x5DA3A3FE,

  0x804040C0, 0x058F8F8A, 0x3F9292AD, 0x219D9DBC, 0x70383848, 0xF1F5F504,

  0x63BCBCDF, 0x77B6B6C1, 0xAFDADA75, 0x42212163, 0x20101030, 0xE5FFFF1A,

  0xFDF3F30E, 0xBFD2D26D, 0x81CDCD4C, 0x180C0C14, 0x26131335, 0xC3ECEC2F,

  0xBE5F5FE1, 0x359797A2, 0x884444CC, 0x2E171739, 0x93C4C457, 0x55A7A7F2,

  0xFC7E7E82, 0x7A3D3D47, 0xC86464AC, 0xBA5D5DE7, 0x3219192B, 0xE6737395,

  0xC06060A0, 0x19818198, 0x9E4F4FD1, 0xA3DCDC7F, 0x44222266, 0x542A2A7E,

  0x3B9090AB, 0x0B888883, 0x8C4646CA, 0xC7EEEE29, 0x6BB8B8D3, 0x2814143C,

  0xA7DEDE79, 0xBC5E5EE2, 0x160B0B1D, 0xADDBDB76, 0xDBE0E03B, 0x64323256,

  0x743A3A4E, 0x140A0A1E, 0x924949DB, 0x0C06060A, 0x4824246C, 0xB85C5CE4,

  0x9FC2C25D, 0xBDD3D36E, 0x43ACACEF, 0xC46262A6, 0x399191A8, 0x319595A4,

  0xD3E4E437, 0xF279798B, 0xD5E7E732, 0x8BC8C843, 0x6E373759, 0xDA6D6DB7,

  0x018D8D8C, 0xB1D5D564, 0x9C4E4ED2, 0x49A9A9E0, 0xD86C6CB4, 0xAC5656FA,

  0xF3F4F407, 0xCFEAEA25, 0xCA6565AF, 0xF47A7A8E, 0x47AEAEE9, 0x10080818,

  0x6FBABAD5, 0xF0787888, 0x4A25256F, 0x5C2E2E72, 0x381C1C24, 0x57A6A6F1,

  0x73B4B4C7, 0x97C6C651, 0xCBE8E823, 0xA1DDDD7C, 0xE874749C, 0x3E1F1F21,

  0x964B4BDD, 0x61BDBDDC, 0x0D8B8B86, 0x0F8A8A85, 0xE0707090, 0x7C3E3E42,

  0x71B5B5C4, 0xCC6666AA, 0x904848D8, 0x06030305, 0xF7F6F601, 0x1C0E0E12,

  0xC26161A3, 0x6A35355F, 0xAE5757F9, 0x69B9B9D0, 0x17868691, 0x99C1C158,

  0x3A1D1D27, 0x279E9EB9, 0xD9E1E138, 0xEBF8F813, 0x2B9898B3, 0x22111133,

  0xD26969BB, 0xA9D9D970, 0x078E8E89, 0x339494A7, 0x2D9B9BB6, 0x3C1E1E22,

  0x15878792, 0xC9E9E920, 0x87CECE49, 0xAA5555FF, 0x50282878, 0xA5DFDF7A,

  0x038C8C8F, 0x59A1A1F8, 0x09898980, 0x1A0D0D17, 0x65BFBFDA, 0xD7E6E631,

  0x844242C6, 0xD06868B8, 0x824141C3, 0x299999B0, 0x5A2D2D77, 0x1E0F0F11,

  0x7BB0B0CB, 0xA85454FC, 0x6DBBBBD6, 0x2C16163A

};

static inline uint32_t

rotr(uint32_t x, int n)

{

  return (x << (32 - n)) | (x >> n);

}

#define SboxExt0(x)   (Ssm0[x])

#define SboxExt1(x)   (rotr(Ssm0[x], 8))

#define SboxExt2(x)   (rotr(Ssm0[x], 16))

#define SboxExt3(x)   (rotr(Ssm0[x], 24))

/* see bearssl.h */

void

br_aes_big_encrypt(unsigned num_rounds, const uint32_t *skey, void *data)

{

  unsigned char *buf;

  uint32_t s0, s1, s2, s3;

  uint32_t t0, t1, t2, t3;

  unsigned u;

  buf = data;

  s0 = br_dec32be(buf);

  s1 = br_dec32be(buf + 4);

  s2 = br_dec32be(buf + 8);

  s3 = br_dec32be(buf + 12);

  s0 ^= skey[0];

  s1 ^= skey[1];

  s2 ^= skey[2];

  s3 ^= skey[3];

  for (u = 1; u < num_rounds; u ++) {

    uint32_t v0, v1, v2, v3;

    v0 = SboxExt0(s0 >> 24)

      ^ SboxExt1((s1 >> 16) & 0xFF)

      ^ SboxExt2((s2 >> 8) & 0xFF)

      ^ SboxExt3(s3 & 0xFF);

    v1 = SboxExt0(s1 >> 24)

      ^ SboxExt1((s2 >> 16) & 0xFF)

      ^ SboxExt2((s3 >> 8) & 0xFF)

      ^ SboxExt3(s0 & 0xFF);

    v2 = SboxExt0(s2 >> 24)

      ^ SboxExt1((s3 >> 16) & 0xFF)

      ^ SboxExt2((s0 >> 8) & 0xFF)

      ^ SboxExt3(s1 & 0xFF);

    v3 = SboxExt0(s3 >> 24)

      ^ SboxExt1((s0 >> 16) & 0xFF)

      ^ SboxExt2((s1 >> 8) & 0xFF)

      ^ SboxExt3(s2 & 0xFF);

    s0 = v0;

    s1 = v1;

    s2 = v2;

    s3 = v3;

    s0 ^= skey[u << 2];

    s1 ^= skey[(u << 2) + 1];

    s2 ^= skey[(u << 2) + 2];

    s3 ^= skey[(u << 2) + 3];

  }

  t0 = ((uint32_t)S[s0 >> 24] << 24)

    | ((uint32_t)S[(s1 >> 16) & 0xFF] << 16)

    | ((uint32_t)S[(s2 >> 8) & 0xFF] << 8)

    | (uint32_t)S[s3 & 0xFF];

  t1 = ((uint32_t)S[s1 >> 24] << 24)

    | ((uint32_t)S[(s2 >> 16) & 0xFF] << 16)

    | ((uint32_t)S[(s3 >> 8) & 0xFF] << 8)

    | (uint32_t)S[s0 & 0xFF];

  t2 = ((uint32_t)S[s2 >> 24] << 24)

    | ((uint32_t)S[(s3 >> 16) & 0xFF] << 16)

    | ((uint32_t)S[(s0 >> 8) & 0xFF] << 8)

    | (uint32_t)S[s1 & 0xFF];

  t3 = ((uint32_t)S[s3 >> 24] << 24)

    | ((uint32_t)S[(s0 >> 16) & 0xFF] << 16)

    | ((uint32_t)S[(s1 >> 8) & 0xFF] << 8)

    | (uint32_t)S[s2 & 0xFF];

  s0 = t0 ^ skey[num_rounds << 2];

  s1 = t1 ^ skey[(num_rounds << 2) + 1];

  s2 = t2 ^ skey[(num_rounds << 2) + 2];

  s3 = t3 ^ skey[(num_rounds << 2) + 3];

  br_enc32be(buf, s0);

  br_enc32be(buf + 4, s1);

  br_enc32be(buf + 8, s2);

  br_enc32be(buf + 12, s3);

}