// SPDX-License-Identifier: BSD-3-Clause
/*
 * Copyright (C) 2005, 2007 Olivier Gay <olivier.gay@a3.epfl.ch>
 * All rights reserved.
 *
 * FIPS 180-2 SHA-224/256/384/512 implementation
 * Last update: 02/02/2007
 * Issue date:  04/30/2005
 */

#include "avb_sha.h"

#define SHFR(x, n) (x >> n)
#define ROTR(x, n) ((x >> n) | (x << ((sizeof(x) << 3) - n)))
#define ROTL(x, n) ((x << n) | (x >> ((sizeof(x) << 3) - n)))
#define CH(x, y, z) ((x & y) ^ (~x & z))
#define MAJ(x, y, z) ((x & y) ^ (x & z) ^ (y & z))

#define SHA512_F1(x) (ROTR(x, 28) ^ ROTR(x, 34) ^ ROTR(x, 39))
#define SHA512_F2(x) (ROTR(x, 14) ^ ROTR(x, 18) ^ ROTR(x, 41))
#define SHA512_F3(x) (ROTR(x, 1) ^ ROTR(x, 8) ^ SHFR(x, 7))
#define SHA512_F4(x) (ROTR(x, 19) ^ ROTR(x, 61) ^ SHFR(x, 6))

#define UNPACK32(x, str)                 \
  {                                      \
    *((str) + 3) = (uint8_t)((x));       \
    *((str) + 2) = (uint8_t)((x) >> 8);  \
    *((str) + 1) = (uint8_t)((x) >> 16); \
    *((str) + 0) = (uint8_t)((x) >> 24); \
  }

#define UNPACK64(x, str)                         \
  {                                              \
    *((str) + 7) = (uint8_t)x;                   \
    *((str) + 6) = (uint8_t)((uint64_t)x >> 8);  \
    *((str) + 5) = (uint8_t)((uint64_t)x >> 16); \
    *((str) + 4) = (uint8_t)((uint64_t)x >> 24); \
    *((str) + 3) = (uint8_t)((uint64_t)x >> 32); \
    *((str) + 2) = (uint8_t)((uint64_t)x >> 40); \
    *((str) + 1) = (uint8_t)((uint64_t)x >> 48); \
    *((str) + 0) = (uint8_t)((uint64_t)x >> 56); \
  }

#define PACK64(str, x)                                                        \
  {                                                                           \
    *(x) =                                                                    \
        ((uint64_t) * ((str) + 7)) | ((uint64_t) * ((str) + 6) << 8) |        \
        ((uint64_t) * ((str) + 5) << 16) | ((uint64_t) * ((str) + 4) << 24) | \
        ((uint64_t) * ((str) + 3) << 32) | ((uint64_t) * ((str) + 2) << 40) | \
        ((uint64_t) * ((str) + 1) << 48) | ((uint64_t) * ((str) + 0) << 56);  \
  }

/* Macros used for loops unrolling */

#define SHA512_SCR(i) \
  { w[i] = SHA512_F4(w[i - 2]) + w[i - 7] + SHA512_F3(w[i - 15]) + w[i - 16]; }

#define SHA512_EXP(a, b, c, d, e, f, g, h, j)                               \
  {                                                                         \
    t1 = wv[h] + SHA512_F2(wv[e]) + CH(wv[e], wv[f], wv[g]) + sha512_k[j] + \
         w[j];                                                              \
    t2 = SHA512_F1(wv[a]) + MAJ(wv[a], wv[b], wv[c]);                       \
    wv[d] += t1;                                                            \
    wv[h] = t1 + t2;                                                        \
  }

static const uint64_t sha512_h0[8] = {0x6a09e667f3bcc908ULL,
                                      0xbb67ae8584caa73bULL,
                                      0x3c6ef372fe94f82bULL,
                                      0xa54ff53a5f1d36f1ULL,
                                      0x510e527fade682d1ULL,
                                      0x9b05688c2b3e6c1fULL,
                                      0x1f83d9abfb41bd6bULL,
                                      0x5be0cd19137e2179ULL};

static const uint64_t sha512_k[80] = {
    0x428a2f98d728ae22ULL, 0x7137449123ef65cdULL, 0xb5c0fbcfec4d3b2fULL,
    0xe9b5dba58189dbbcULL, 0x3956c25bf348b538ULL, 0x59f111f1b605d019ULL,
    0x923f82a4af194f9bULL, 0xab1c5ed5da6d8118ULL, 0xd807aa98a3030242ULL,
    0x12835b0145706fbeULL, 0x243185be4ee4b28cULL, 0x550c7dc3d5ffb4e2ULL,
    0x72be5d74f27b896fULL, 0x80deb1fe3b1696b1ULL, 0x9bdc06a725c71235ULL,
    0xc19bf174cf692694ULL, 0xe49b69c19ef14ad2ULL, 0xefbe4786384f25e3ULL,
    0x0fc19dc68b8cd5b5ULL, 0x240ca1cc77ac9c65ULL, 0x2de92c6f592b0275ULL,
    0x4a7484aa6ea6e483ULL, 0x5cb0a9dcbd41fbd4ULL, 0x76f988da831153b5ULL,
    0x983e5152ee66dfabULL, 0xa831c66d2db43210ULL, 0xb00327c898fb213fULL,
    0xbf597fc7beef0ee4ULL, 0xc6e00bf33da88fc2ULL, 0xd5a79147930aa725ULL,
    0x06ca6351e003826fULL, 0x142929670a0e6e70ULL, 0x27b70a8546d22ffcULL,
    0x2e1b21385c26c926ULL, 0x4d2c6dfc5ac42aedULL, 0x53380d139d95b3dfULL,
    0x650a73548baf63deULL, 0x766a0abb3c77b2a8ULL, 0x81c2c92e47edaee6ULL,
    0x92722c851482353bULL, 0xa2bfe8a14cf10364ULL, 0xa81a664bbc423001ULL,
    0xc24b8b70d0f89791ULL, 0xc76c51a30654be30ULL, 0xd192e819d6ef5218ULL,
    0xd69906245565a910ULL, 0xf40e35855771202aULL, 0x106aa07032bbd1b8ULL,
    0x19a4c116b8d2d0c8ULL, 0x1e376c085141ab53ULL, 0x2748774cdf8eeb99ULL,
    0x34b0bcb5e19b48a8ULL, 0x391c0cb3c5c95a63ULL, 0x4ed8aa4ae3418acbULL,
    0x5b9cca4f7763e373ULL, 0x682e6ff3d6b2b8a3ULL, 0x748f82ee5defb2fcULL,
    0x78a5636f43172f60ULL, 0x84c87814a1f0ab72ULL, 0x8cc702081a6439ecULL,
    0x90befffa23631e28ULL, 0xa4506cebde82bde9ULL, 0xbef9a3f7b2c67915ULL,
    0xc67178f2e372532bULL, 0xca273eceea26619cULL, 0xd186b8c721c0c207ULL,
    0xeada7dd6cde0eb1eULL, 0xf57d4f7fee6ed178ULL, 0x06f067aa72176fbaULL,
    0x0a637dc5a2c898a6ULL, 0x113f9804bef90daeULL, 0x1b710b35131c471bULL,
    0x28db77f523047d84ULL, 0x32caab7b40c72493ULL, 0x3c9ebe0a15c9bebcULL,
    0x431d67c49c100d4cULL, 0x4cc5d4becb3e42b6ULL, 0x597f299cfc657e2aULL,
    0x5fcb6fab3ad6faecULL, 0x6c44198c4a475817ULL};

/* SHA-512 implementation */

void avb_sha512_init(AvbSHA512Ctx* ctx) {
#ifdef UNROLL_LOOPS_SHA512
  ctx->h[0] = sha512_h0[0];
  ctx->h[1] = sha512_h0[1];
  ctx->h[2] = sha512_h0[2];
  ctx->h[3] = sha512_h0[3];
  ctx->h[4] = sha512_h0[4];
  ctx->h[5] = sha512_h0[5];
  ctx->h[6] = sha512_h0[6];
  ctx->h[7] = sha512_h0[7];
#else
  int i;

  for (i = 0; i < 8; i++)
    ctx->h[i] = sha512_h0[i];
#endif /* UNROLL_LOOPS_SHA512 */

  ctx->len = 0;
  ctx->tot_len = 0;
}

static void SHA512_transform(AvbSHA512Ctx* ctx,
                             const uint8_t* message,
                             size_t block_nb) {
  uint64_t w[80];
  uint64_t wv[8];
  uint64_t t1, t2;
  const uint8_t* sub_block;
  size_t i, j;

  for (i = 0; i < block_nb; i++) {
    sub_block = message + (i << 7);

#ifdef UNROLL_LOOPS_SHA512
    PACK64(&sub_block[0], &w[0]);
    PACK64(&sub_block[8], &w[1]);
    PACK64(&sub_block[16], &w[2]);
    PACK64(&sub_block[24], &w[3]);
    PACK64(&sub_block[32], &w[4]);
    PACK64(&sub_block[40], &w[5]);
    PACK64(&sub_block[48], &w[6]);
    PACK64(&sub_block[56], &w[7]);
    PACK64(&sub_block[64], &w[8]);
    PACK64(&sub_block[72], &w[9]);
    PACK64(&sub_block[80], &w[10]);
    PACK64(&sub_block[88], &w[11]);
    PACK64(&sub_block[96], &w[12]);
    PACK64(&sub_block[104], &w[13]);
    PACK64(&sub_block[112], &w[14]);
    PACK64(&sub_block[120], &w[15]);

    SHA512_SCR(16);
    SHA512_SCR(17);
    SHA512_SCR(18);
    SHA512_SCR(19);
    SHA512_SCR(20);
    SHA512_SCR(21);
    SHA512_SCR(22);
    SHA512_SCR(23);
    SHA512_SCR(24);
    SHA512_SCR(25);
    SHA512_SCR(26);
    SHA512_SCR(27);
    SHA512_SCR(28);
    SHA512_SCR(29);
    SHA512_SCR(30);
    SHA512_SCR(31);
    SHA512_SCR(32);
    SHA512_SCR(33);
    SHA512_SCR(34);
    SHA512_SCR(35);
    SHA512_SCR(36);
    SHA512_SCR(37);
    SHA512_SCR(38);
    SHA512_SCR(39);
    SHA512_SCR(40);
    SHA512_SCR(41);
    SHA512_SCR(42);
    SHA512_SCR(43);
    SHA512_SCR(44);
    SHA512_SCR(45);
    SHA512_SCR(46);
    SHA512_SCR(47);
    SHA512_SCR(48);
    SHA512_SCR(49);
    SHA512_SCR(50);
    SHA512_SCR(51);
    SHA512_SCR(52);
    SHA512_SCR(53);
    SHA512_SCR(54);
    SHA512_SCR(55);
    SHA512_SCR(56);
    SHA512_SCR(57);
    SHA512_SCR(58);
    SHA512_SCR(59);
    SHA512_SCR(60);
    SHA512_SCR(61);
    SHA512_SCR(62);
    SHA512_SCR(63);
    SHA512_SCR(64);
    SHA512_SCR(65);
    SHA512_SCR(66);
    SHA512_SCR(67);
    SHA512_SCR(68);
    SHA512_SCR(69);
    SHA512_SCR(70);
    SHA512_SCR(71);
    SHA512_SCR(72);
    SHA512_SCR(73);
    SHA512_SCR(74);
    SHA512_SCR(75);
    SHA512_SCR(76);
    SHA512_SCR(77);
    SHA512_SCR(78);
    SHA512_SCR(79);

    wv[0] = ctx->h[0];
    wv[1] = ctx->h[1];
    wv[2] = ctx->h[2];
    wv[3] = ctx->h[3];
    wv[4] = ctx->h[4];
    wv[5] = ctx->h[5];
    wv[6] = ctx->h[6];
    wv[7] = ctx->h[7];

    j = 0;

    do {
      SHA512_EXP(0, 1, 2, 3, 4, 5, 6, 7, j);
      j++;
      SHA512_EXP(7, 0, 1, 2, 3, 4, 5, 6, j);
      j++;
      SHA512_EXP(6, 7, 0, 1, 2, 3, 4, 5, j);
      j++;
      SHA512_EXP(5, 6, 7, 0, 1, 2, 3, 4, j);
      j++;
      SHA512_EXP(4, 5, 6, 7, 0, 1, 2, 3, j);
      j++;
      SHA512_EXP(3, 4, 5, 6, 7, 0, 1, 2, j);
      j++;
      SHA512_EXP(2, 3, 4, 5, 6, 7, 0, 1, j);
      j++;
      SHA512_EXP(1, 2, 3, 4, 5, 6, 7, 0, j);
      j++;
    } while (j < 80);

    ctx->h[0] += wv[0];
    ctx->h[1] += wv[1];
    ctx->h[2] += wv[2];
    ctx->h[3] += wv[3];
    ctx->h[4] += wv[4];
    ctx->h[5] += wv[5];
    ctx->h[6] += wv[6];
    ctx->h[7] += wv[7];
#else
    for (j = 0; j < 16; j++) {
      PACK64(&sub_block[j << 3], &w[j]);
    }

    for (j = 16; j < 80; j++) {
      SHA512_SCR(j);
    }

    for (j = 0; j < 8; j++) {
      wv[j] = ctx->h[j];
    }

    for (j = 0; j < 80; j++) {
      t1 = wv[7] + SHA512_F2(wv[4]) + CH(wv[4], wv[5], wv[6]) + sha512_k[j] +
           w[j];
      t2 = SHA512_F1(wv[0]) + MAJ(wv[0], wv[1], wv[2]);
      wv[7] = wv[6];
      wv[6] = wv[5];
      wv[5] = wv[4];
      wv[4] = wv[3] + t1;
      wv[3] = wv[2];
      wv[2] = wv[1];
      wv[1] = wv[0];
      wv[0] = t1 + t2;
    }

    for (j = 0; j < 8; j++)
      ctx->h[j] += wv[j];
#endif /* UNROLL_LOOPS_SHA512 */
  }
}

void avb_sha512_update(AvbSHA512Ctx* ctx, const uint8_t* data, size_t len) {
  size_t block_nb;
  size_t new_len, rem_len, tmp_len;
  const uint8_t* shifted_data;

  tmp_len = AVB_SHA512_BLOCK_SIZE - ctx->len;
  rem_len = len < tmp_len ? len : tmp_len;

  avb_memcpy(&ctx->block[ctx->len], data, rem_len);

  if (ctx->len + len < AVB_SHA512_BLOCK_SIZE) {
    ctx->len += len;
    return;
  }

  new_len = len - rem_len;
  block_nb = new_len / AVB_SHA512_BLOCK_SIZE;

  shifted_data = data + rem_len;

  SHA512_transform(ctx, ctx->block, 1);
  SHA512_transform(ctx, shifted_data, block_nb);

  rem_len = new_len % AVB_SHA512_BLOCK_SIZE;

  avb_memcpy(ctx->block, &shifted_data[block_nb << 7], rem_len);

  ctx->len = rem_len;
  ctx->tot_len += (block_nb + 1) << 7;
}

uint8_t* avb_sha512_final(AvbSHA512Ctx* ctx) {
  size_t block_nb;
  size_t pm_len;
  uint64_t len_b;

#ifndef UNROLL_LOOPS_SHA512
  size_t i;
#endif

  block_nb =
      1 + ((AVB_SHA512_BLOCK_SIZE - 17) < (ctx->len % AVB_SHA512_BLOCK_SIZE));

  len_b = (ctx->tot_len + ctx->len) << 3;
  pm_len = block_nb << 7;

  avb_memset(ctx->block + ctx->len, 0, pm_len - ctx->len);
  ctx->block[ctx->len] = 0x80;
  UNPACK64(len_b, ctx->block + pm_len - 8);

  SHA512_transform(ctx, ctx->block, block_nb);

#ifdef UNROLL_LOOPS_SHA512
  UNPACK64(ctx->h[0], &ctx->buf[0]);
  UNPACK64(ctx->h[1], &ctx->buf[8]);
  UNPACK64(ctx->h[2], &ctx->buf[16]);
  UNPACK64(ctx->h[3], &ctx->buf[24]);
  UNPACK64(ctx->h[4], &ctx->buf[32]);
  UNPACK64(ctx->h[5], &ctx->buf[40]);
  UNPACK64(ctx->h[6], &ctx->buf[48]);
  UNPACK64(ctx->h[7], &ctx->buf[56]);
#else
  for (i = 0; i < 8; i++)
    UNPACK64(ctx->h[i], &ctx->buf[i << 3]);
#endif /* UNROLL_LOOPS_SHA512 */

  return ctx->buf;
}