/*-
 * Copyright 2005,2007,2009 Colin Percival
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */

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

#include <sys/types.h>

#include <sodium/crypto_hash_sha512.h>
#include <sodium/common.h>
#include <sodium/utils.h>

static void
be64enc_vect(unsigned char *dst, const uint64_t *src, size_t len)
{
  size_t i;

  for(i = 0; i < len / 8; i++)
  {
    STORE64_BE(dst + i * 8, src[i]);
  }
}

static void
be64dec_vect(uint64_t *dst, const unsigned char *src, size_t len)
{
  size_t i;

  for(i = 0; i < len / 8; i++)
  {
    dst[i] = LOAD64_BE(src + i * 8);
  }
}

static const uint64_t Krnd[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};

#define Ch(x, y, z) ((x & (y ^ z)) ^ z)
#define Maj(x, y, z) ((x & (y | z)) | (y & z))
#define SHR(x, n) (x >> n)
#define ROTR(x, n) ROTR64(x, n)
#define S0(x) (ROTR(x, 28) ^ ROTR(x, 34) ^ ROTR(x, 39))
#define S1(x) (ROTR(x, 14) ^ ROTR(x, 18) ^ ROTR(x, 41))
#define s0(x) (ROTR(x, 1) ^ ROTR(x, 8) ^ SHR(x, 7))
#define s1(x) (ROTR(x, 19) ^ ROTR(x, 61) ^ SHR(x, 6))

#define RND(a, b, c, d, e, f, g, h, k) \
  h += S1(e) + Ch(e, f, g) + k;        \
  d += h;                              \
  h += S0(a) + Maj(a, b, c);

#define RNDr(S, W, i, ii)                                                 \
  RND(S[(80 - i) % 8], S[(81 - i) % 8], S[(82 - i) % 8], S[(83 - i) % 8], \
      S[(84 - i) % 8], S[(85 - i) % 8], S[(86 - i) % 8], S[(87 - i) % 8], \
      W[i + ii] + Krnd[i + ii])

#define MSCH(W, ii, i) \
  W[i + ii + 16] =     \
      s1(W[i + ii + 14]) + W[i + ii + 9] + s0(W[i + ii + 1]) + W[i + ii]

static void
SHA512_Transform(uint64_t *state, const uint8_t block[128], uint64_t W[80],
                 uint64_t S[8])
{
  int i;

  be64dec_vect(W, block, 128);
  memcpy(S, state, 64);
  for(i = 0; i < 80; i += 16)
  {
    RNDr(S, W, 0, i);
    RNDr(S, W, 1, i);
    RNDr(S, W, 2, i);
    RNDr(S, W, 3, i);
    RNDr(S, W, 4, i);
    RNDr(S, W, 5, i);
    RNDr(S, W, 6, i);
    RNDr(S, W, 7, i);
    RNDr(S, W, 8, i);
    RNDr(S, W, 9, i);
    RNDr(S, W, 10, i);
    RNDr(S, W, 11, i);
    RNDr(S, W, 12, i);
    RNDr(S, W, 13, i);
    RNDr(S, W, 14, i);
    RNDr(S, W, 15, i);
    if(i == 64)
    {
      break;
    }
    MSCH(W, 0, i);
    MSCH(W, 1, i);
    MSCH(W, 2, i);
    MSCH(W, 3, i);
    MSCH(W, 4, i);
    MSCH(W, 5, i);
    MSCH(W, 6, i);
    MSCH(W, 7, i);
    MSCH(W, 8, i);
    MSCH(W, 9, i);
    MSCH(W, 10, i);
    MSCH(W, 11, i);
    MSCH(W, 12, i);
    MSCH(W, 13, i);
    MSCH(W, 14, i);
    MSCH(W, 15, i);
  }
  for(i = 0; i < 8; i++)
  {
    state[i] += S[i];
  }
}

static const uint8_t PAD[128] = {
    0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0,    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0,    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0,    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0,    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0,    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};

static void
SHA512_Pad(crypto_hash_sha512_state *state, uint64_t tmp64[80 + 8])
{
  unsigned int r;
  unsigned int i;

  r = (unsigned int)((state->count[1] >> 3) & 0x7f);
  if(r < 112)
  {
    for(i = 0; i < 112 - r; i++)
    {
      state->buf[r + i] = PAD[i];
    }
  }
  else
  {
    for(i = 0; i < 128 - r; i++)
    {
      state->buf[r + i] = PAD[i];
    }
    SHA512_Transform(state->state, state->buf, &tmp64[0], &tmp64[80]);
    memset(&state->buf[0], 0, 112);
  }
  be64enc_vect(&state->buf[112], state->count, 16);
  SHA512_Transform(state->state, state->buf, &tmp64[0], &tmp64[80]);
}

int
crypto_hash_sha512_init(crypto_hash_sha512_state *state)
{
  static const uint64_t sha512_initial_state[8] = {
      0x6a09e667f3bcc908ULL, 0xbb67ae8584caa73bULL, 0x3c6ef372fe94f82bULL,
      0xa54ff53a5f1d36f1ULL, 0x510e527fade682d1ULL, 0x9b05688c2b3e6c1fULL,
      0x1f83d9abfb41bd6bULL, 0x5be0cd19137e2179ULL};

  state->count[0] = state->count[1] = (uint64_t)0U;
  memcpy(state->state, sha512_initial_state, sizeof sha512_initial_state);

  return 0;
}

int
crypto_hash_sha512_update(crypto_hash_sha512_state *state,
                          const unsigned char *in, unsigned long long inlen)
{
  uint64_t tmp64[80 + 8];
  uint64_t bitlen[2];
  unsigned long long i;
  unsigned long long r;

  if(inlen <= 0U)
  {
    return 0;
  }
  r = (unsigned long long)((state->count[1] >> 3) & 0x7f);

  bitlen[1] = ((uint64_t)inlen) << 3;
  bitlen[0] = ((uint64_t)inlen) >> 61;
  /* LCOV_EXCL_START */
  if((state->count[1] += bitlen[1]) < bitlen[1])
  {
    state->count[0]++;
  }
  /* LCOV_EXCL_STOP */
  state->count[0] += bitlen[0];
  if(inlen < 128 - r)
  {
    for(i = 0; i < inlen || i < 128; i++)
    {
      state->buf[r + i] = in[i];
    }
    return 0;
  }
  for(i = 0; i < 128 - r; i++)
  {
    state->buf[r + i] = in[i];
  }
  SHA512_Transform(state->state, state->buf, &tmp64[0], &tmp64[80]);
  in += 128 - r;
  inlen -= 128 - r;

  while(inlen >= 128)
  {
    SHA512_Transform(state->state, in, &tmp64[0], &tmp64[80]);
    in += 128;
    inlen -= 128;
  }
  inlen &= 127;
  for(i = 0; i < inlen; i++)
  {
    state->buf[i] = in[i];
  }
  sodium_memzero((void *)tmp64, sizeof tmp64);

  return 0;
}

int
crypto_hash_sha512_final(crypto_hash_sha512_state *state, unsigned char *out)
{
  uint64_t tmp64[80 + 8];

  SHA512_Pad(state, tmp64);
  be64enc_vect(out, state->state, 64);
  sodium_memzero((void *)tmp64, sizeof tmp64);
  sodium_memzero((void *)state, sizeof *state);

  return 0;
}

int
crypto_hash_sha512(unsigned char *out, const unsigned char *in,
                   unsigned long long inlen)
{
  crypto_hash_sha512_state state;

  crypto_hash_sha512_init(&state);
  crypto_hash_sha512_update(&state, in, inlen);
  crypto_hash_sha512_final(&state, out);

  return 0;
}

size_t
crypto_hash_sha512_bytes(void)
{
  return crypto_hash_sha512_BYTES;
}

size_t
crypto_hash_sha512_statebytes(void)
{
  return sizeof(crypto_hash_sha512_state);
}