#include <stdint.h>
#include <string.h>

#include "blake2.h"
#include <sodium/private/common.h>

CRYPTO_ALIGN(64)
static const uint64_t blake2b_IV[8] = {
    0x6a09e667f3bcc908ULL, 0xbb67ae8584caa73bULL, 0x3c6ef372fe94f82bULL,
    0xa54ff53a5f1d36f1ULL, 0x510e527fade682d1ULL, 0x9b05688c2b3e6c1fULL,
    0x1f83d9abfb41bd6bULL, 0x5be0cd19137e2179ULL};

static const uint8_t blake2b_sigma[12][16] = {
    {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15},
    {14, 10, 4, 8, 9, 15, 13, 6, 1, 12, 0, 2, 11, 7, 5, 3},
    {11, 8, 12, 0, 5, 2, 15, 13, 10, 14, 3, 6, 7, 1, 9, 4},
    {7, 9, 3, 1, 13, 12, 11, 14, 2, 6, 5, 10, 4, 0, 15, 8},
    {9, 0, 5, 7, 2, 4, 10, 15, 14, 1, 11, 12, 6, 8, 3, 13},
    {2, 12, 6, 10, 0, 11, 8, 3, 4, 13, 7, 5, 15, 14, 1, 9},
    {12, 5, 1, 15, 14, 13, 4, 10, 0, 7, 6, 3, 9, 2, 8, 11},
    {13, 11, 7, 14, 12, 1, 3, 9, 5, 0, 15, 4, 8, 6, 2, 10},
    {6, 15, 14, 9, 11, 3, 0, 8, 12, 2, 13, 7, 1, 4, 10, 5},
    {10, 2, 8, 4, 7, 6, 1, 5, 15, 11, 9, 14, 3, 12, 13, 0},
    {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15},
    {14, 10, 4, 8, 9, 15, 13, 6, 1, 12, 0, 2, 11, 7, 5, 3}};

int
blake2b_compress_ref(blake2b_state *S, const uint8_t block[BLAKE2B_BLOCKBYTES])
{
  uint64_t m[16];
  uint64_t v[16];
  int i;

  for(i = 0; i < 16; ++i)
  {
    m[i] = LOAD64_LE(block + i * sizeof(m[i]));
  }
  for(i = 0; i < 8; ++i)
  {
    v[i] = S->h[i];
  }
  v[8]  = blake2b_IV[0];
  v[9]  = blake2b_IV[1];
  v[10] = blake2b_IV[2];
  v[11] = blake2b_IV[3];
  v[12] = S->t[0] ^ blake2b_IV[4];
  v[13] = S->t[1] ^ blake2b_IV[5];
  v[14] = S->f[0] ^ blake2b_IV[6];
  v[15] = S->f[1] ^ blake2b_IV[7];
#define G(r, i, a, b, c, d)                     \
  do                                            \
  {                                             \
    a = a + b + m[blake2b_sigma[r][2 * i + 0]]; \
    d = ROTR64(d ^ a, 32);                      \
    c = c + d;                                  \
    b = ROTR64(b ^ c, 24);                      \
    a = a + b + m[blake2b_sigma[r][2 * i + 1]]; \
    d = ROTR64(d ^ a, 16);                      \
    c = c + d;                                  \
    b = ROTR64(b ^ c, 63);                      \
  } while(0)
#define ROUND(r)                       \
  do                                   \
  {                                    \
    G(r, 0, v[0], v[4], v[8], v[12]);  \
    G(r, 1, v[1], v[5], v[9], v[13]);  \
    G(r, 2, v[2], v[6], v[10], v[14]); \
    G(r, 3, v[3], v[7], v[11], v[15]); \
    G(r, 4, v[0], v[5], v[10], v[15]); \
    G(r, 5, v[1], v[6], v[11], v[12]); \
    G(r, 6, v[2], v[7], v[8], v[13]);  \
    G(r, 7, v[3], v[4], v[9], v[14]);  \
  } while(0)
  ROUND(0);
  ROUND(1);
  ROUND(2);
  ROUND(3);
  ROUND(4);
  ROUND(5);
  ROUND(6);
  ROUND(7);
  ROUND(8);
  ROUND(9);
  ROUND(10);
  ROUND(11);

  for(i = 0; i < 8; ++i)
  {
    S->h[i] = S->h[i] ^ v[i] ^ v[i + 8];
  }

#undef G
#undef ROUND
  return 0;
}