/* Based on the public domain implementation in
 * crypto_hash/sha512/ref/ from http://bench.cr.yp.to/supercop.html
 * by D. J. Bernstein */

#include "sha2.h"

typedef unsigned long long uint64;

static uint64 load_bigendian(const unsigned char *x) {
  return (uint64)(x[7]) | (((uint64)(x[6])) << 8) | (((uint64)(x[5])) << 16) |
         (((uint64)(x[4])) << 24) | (((uint64)(x[3])) << 32) |
         (((uint64)(x[2])) << 40) | (((uint64)(x[1])) << 48) |
         (((uint64)(x[0])) << 56);
}

static void store_bigendian(unsigned char *x, uint64 u) {
  x[7] = u;
  u >>= 8;
  x[6] = u;
  u >>= 8;
  x[5] = u;
  u >>= 8;
  x[4] = u;
  u >>= 8;
  x[3] = u;
  u >>= 8;
  x[2] = u;
  u >>= 8;
  x[1] = u;
  u >>= 8;
  x[0] = u;
}

#define SHR(x, c) ((x) >> (c))
#define ROTR(x, c) (((x) >> (c)) | ((x) << (64 - (c))))

#define Ch(x, y, z) ((x & y) ^ (~x & z))
#define Maj(x, y, z) ((x & y) ^ (x & z) ^ (y & z))
#define Sigma0(x) (ROTR(x, 28) ^ ROTR(x, 34) ^ ROTR(x, 39))
#define Sigma1(x) (ROTR(x, 14) ^ ROTR(x, 18) ^ ROTR(x, 41))
#define sigma0(x) (ROTR(x, 1) ^ ROTR(x, 8) ^ SHR(x, 7))
#define sigma1(x) (ROTR(x, 19) ^ ROTR(x, 61) ^ SHR(x, 6))

#define M(w0, w14, w9, w1) w0 = sigma1(w14) + w9 + sigma0(w1) + w0;

#define EXPAND                                                                 \
  M(w0, w14, w9, w1)                                                           \
  M(w1, w15, w10, w2)                                                          \
  M(w2, w0, w11, w3)                                                           \
  M(w3, w1, w12, w4)                                                           \
  M(w4, w2, w13, w5)                                                           \
  M(w5, w3, w14, w6)                                                           \
  M(w6, w4, w15, w7)                                                           \
  M(w7, w5, w0, w8)                                                            \
  M(w8, w6, w1, w9)                                                            \
  M(w9, w7, w2, w10)                                                           \
  M(w10, w8, w3, w11)                                                          \
  M(w11, w9, w4, w12)                                                          \
  M(w12, w10, w5, w13)                                                         \
  M(w13, w11, w6, w14)                                                         \
  M(w14, w12, w7, w15)                                                         \
  M(w15, w13, w8, w0)

#define F(w, k)                                                                \
  T1 = h + Sigma1(e) + Ch(e, f, g) + k + w;                                    \
  T2 = Sigma0(a) + Maj(a, b, c);                                               \
  h = g;                                                                       \
  g = f;                                                                       \
  f = e;                                                                       \
  e = d + T1;                                                                  \
  d = c;                                                                       \
  c = b;                                                                       \
  b = a;                                                                       \
  a = T1 + T2;

static int crypto_hashblocks_sha512(unsigned char *statebytes,
                                    const unsigned char *in,
                                    unsigned long long inlen) {
  uint64 state[8];
  uint64 a;
  uint64 b;
  uint64 c;
  uint64 d;
  uint64 e;
  uint64 f;
  uint64 g;
  uint64 h;
  uint64 T1;
  uint64 T2;

  a = load_bigendian(statebytes + 0);
  state[0] = a;
  b = load_bigendian(statebytes + 8);
  state[1] = b;
  c = load_bigendian(statebytes + 16);
  state[2] = c;
  d = load_bigendian(statebytes + 24);
  state[3] = d;
  e = load_bigendian(statebytes + 32);
  state[4] = e;
  f = load_bigendian(statebytes + 40);
  state[5] = f;
  g = load_bigendian(statebytes + 48);
  state[6] = g;
  h = load_bigendian(statebytes + 56);
  state[7] = h;

  while (inlen >= 128) {
    uint64 w0 = load_bigendian(in + 0);
    uint64 w1 = load_bigendian(in + 8);
    uint64 w2 = load_bigendian(in + 16);
    uint64 w3 = load_bigendian(in + 24);
    uint64 w4 = load_bigendian(in + 32);
    uint64 w5 = load_bigendian(in + 40);
    uint64 w6 = load_bigendian(in + 48);
    uint64 w7 = load_bigendian(in + 56);
    uint64 w8 = load_bigendian(in + 64);
    uint64 w9 = load_bigendian(in + 72);
    uint64 w10 = load_bigendian(in + 80);
    uint64 w11 = load_bigendian(in + 88);
    uint64 w12 = load_bigendian(in + 96);
    uint64 w13 = load_bigendian(in + 104);
    uint64 w14 = load_bigendian(in + 112);
    uint64 w15 = load_bigendian(in + 120);

    F(w0, 0x428a2f98d728ae22ULL)
    F(w1, 0x7137449123ef65cdULL)
    F(w2, 0xb5c0fbcfec4d3b2fULL)
    F(w3, 0xe9b5dba58189dbbcULL)
    F(w4, 0x3956c25bf348b538ULL)
    F(w5, 0x59f111f1b605d019ULL)
    F(w6, 0x923f82a4af194f9bULL)
    F(w7, 0xab1c5ed5da6d8118ULL)
    F(w8, 0xd807aa98a3030242ULL)
    F(w9, 0x12835b0145706fbeULL)
    F(w10, 0x243185be4ee4b28cULL)
    F(w11, 0x550c7dc3d5ffb4e2ULL)
    F(w12, 0x72be5d74f27b896fULL)
    F(w13, 0x80deb1fe3b1696b1ULL)
    F(w14, 0x9bdc06a725c71235ULL)
    F(w15, 0xc19bf174cf692694ULL)

    EXPAND

    F(w0, 0xe49b69c19ef14ad2ULL)
    F(w1, 0xefbe4786384f25e3ULL)
    F(w2, 0x0fc19dc68b8cd5b5ULL)
    F(w3, 0x240ca1cc77ac9c65ULL)
    F(w4, 0x2de92c6f592b0275ULL)
    F(w5, 0x4a7484aa6ea6e483ULL)
    F(w6, 0x5cb0a9dcbd41fbd4ULL)
    F(w7, 0x76f988da831153b5ULL)
    F(w8, 0x983e5152ee66dfabULL)
    F(w9, 0xa831c66d2db43210ULL)
    F(w10, 0xb00327c898fb213fULL)
    F(w11, 0xbf597fc7beef0ee4ULL)
    F(w12, 0xc6e00bf33da88fc2ULL)
    F(w13, 0xd5a79147930aa725ULL)
    F(w14, 0x06ca6351e003826fULL)
    F(w15, 0x142929670a0e6e70ULL)

    EXPAND

    F(w0, 0x27b70a8546d22ffcULL)
    F(w1, 0x2e1b21385c26c926ULL)
    F(w2, 0x4d2c6dfc5ac42aedULL)
    F(w3, 0x53380d139d95b3dfULL)
    F(w4, 0x650a73548baf63deULL)
    F(w5, 0x766a0abb3c77b2a8ULL)
    F(w6, 0x81c2c92e47edaee6ULL)
    F(w7, 0x92722c851482353bULL)
    F(w8, 0xa2bfe8a14cf10364ULL)
    F(w9, 0xa81a664bbc423001ULL)
    F(w10, 0xc24b8b70d0f89791ULL)
    F(w11, 0xc76c51a30654be30ULL)
    F(w12, 0xd192e819d6ef5218ULL)
    F(w13, 0xd69906245565a910ULL)
    F(w14, 0xf40e35855771202aULL)
    F(w15, 0x106aa07032bbd1b8ULL)

    EXPAND

    F(w0, 0x19a4c116b8d2d0c8ULL)
    F(w1, 0x1e376c085141ab53ULL)
    F(w2, 0x2748774cdf8eeb99ULL)
    F(w3, 0x34b0bcb5e19b48a8ULL)
    F(w4, 0x391c0cb3c5c95a63ULL)
    F(w5, 0x4ed8aa4ae3418acbULL)
    F(w6, 0x5b9cca4f7763e373ULL)
    F(w7, 0x682e6ff3d6b2b8a3ULL)
    F(w8, 0x748f82ee5defb2fcULL)
    F(w9, 0x78a5636f43172f60ULL)
    F(w10, 0x84c87814a1f0ab72ULL)
    F(w11, 0x8cc702081a6439ecULL)
    F(w12, 0x90befffa23631e28ULL)
    F(w13, 0xa4506cebde82bde9ULL)
    F(w14, 0xbef9a3f7b2c67915ULL)
    F(w15, 0xc67178f2e372532bULL)

    EXPAND

    F(w0, 0xca273eceea26619cULL)
    F(w1, 0xd186b8c721c0c207ULL)
    F(w2, 0xeada7dd6cde0eb1eULL)
    F(w3, 0xf57d4f7fee6ed178ULL)
    F(w4, 0x06f067aa72176fbaULL)
    F(w5, 0x0a637dc5a2c898a6ULL)
    F(w6, 0x113f9804bef90daeULL)
    F(w7, 0x1b710b35131c471bULL)
    F(w8, 0x28db77f523047d84ULL)
    F(w9, 0x32caab7b40c72493ULL)
    F(w10, 0x3c9ebe0a15c9bebcULL)
    F(w11, 0x431d67c49c100d4cULL)
    F(w12, 0x4cc5d4becb3e42b6ULL)
    F(w13, 0x597f299cfc657e2aULL)
    F(w14, 0x5fcb6fab3ad6faecULL)
    F(w15, 0x6c44198c4a475817ULL)

    a += state[0];
    b += state[1];
    c += state[2];
    d += state[3];
    e += state[4];
    f += state[5];
    g += state[6];
    h += state[7];

    state[0] = a;
    state[1] = b;
    state[2] = c;
    state[3] = d;
    state[4] = e;
    state[5] = f;
    state[6] = g;
    state[7] = h;

    in += 128;
    inlen -= 128;
  }

  store_bigendian(statebytes + 0, state[0]);
  store_bigendian(statebytes + 8, state[1]);
  store_bigendian(statebytes + 16, state[2]);
  store_bigendian(statebytes + 24, state[3]);
  store_bigendian(statebytes + 32, state[4]);
  store_bigendian(statebytes + 40, state[5]);
  store_bigendian(statebytes + 48, state[6]);
  store_bigendian(statebytes + 56, state[7]);

  return inlen;
}

#define blocks crypto_hashblocks_sha512

static const unsigned char iv_384[64] = {
    0xcb, 0xbb, 0x9d, 0x5d, 0xc1, 0x05, 0x9e, 0xd8, 0x62, 0x9a, 0x29,
    0x2a, 0x36, 0x7c, 0xd5, 0x07, 0x91, 0x59, 0x01, 0x5a, 0x30, 0x70,
    0xdd, 0x17, 0x15, 0x2f, 0xec, 0xd8, 0xf7, 0x0e, 0x59, 0x39, 0x67,
    0x33, 0x26, 0x67, 0xff, 0xc0, 0x0b, 0x31, 0x8e, 0xb4, 0x4a, 0x87,
    0x68, 0x58, 0x15, 0x11, 0xdb, 0x0c, 0x2e, 0x0d, 0x64, 0xf9, 0x8f,
    0xa7, 0x47, 0xb5, 0x48, 0x1d, 0xbe, 0xfa, 0x4f, 0xa4};

static const unsigned char iv_512[64] = {
    0x6a, 0x09, 0xe6, 0x67, 0xf3, 0xbc, 0xc9, 0x08, 0xbb, 0x67, 0xae,
    0x85, 0x84, 0xca, 0xa7, 0x3b, 0x3c, 0x6e, 0xf3, 0x72, 0xfe, 0x94,
    0xf8, 0x2b, 0xa5, 0x4f, 0xf5, 0x3a, 0x5f, 0x1d, 0x36, 0xf1, 0x51,
    0x0e, 0x52, 0x7f, 0xad, 0xe6, 0x82, 0xd1, 0x9b, 0x05, 0x68, 0x8c,
    0x2b, 0x3e, 0x6c, 0x1f, 0x1f, 0x83, 0xd9, 0xab, 0xfb, 0x41, 0xbd,
    0x6b, 0x5b, 0xe0, 0xcd, 0x19, 0x13, 0x7e, 0x21, 0x79};

int sha384(unsigned char *out, const unsigned char *in,
           unsigned long long inlen) {
  unsigned char h[64];
  unsigned char padded[256];
  unsigned int i;
  unsigned long long bytes = inlen;

  for (i = 0; i < 64; ++i)
    h[i] = iv_384[i];

  blocks(h, in, inlen);
  in += inlen;
  inlen &= 127;
  in -= inlen;

  for (i = 0; i < inlen; ++i)
    padded[i] = in[i];
  padded[inlen] = 0x80;

  if (inlen < 112) {
    for (i = inlen + 1; i < 119; ++i)
      padded[i] = 0;
    padded[119] = bytes >> 61;
    padded[120] = bytes >> 53;
    padded[121] = bytes >> 45;
    padded[122] = bytes >> 37;
    padded[123] = bytes >> 29;
    padded[124] = bytes >> 21;
    padded[125] = bytes >> 13;
    padded[126] = bytes >> 5;
    padded[127] = bytes << 3;
    blocks(h, padded, 128);
  } else {
    for (i = inlen + 1; i < 247; ++i)
      padded[i] = 0;
    padded[247] = bytes >> 61;
    padded[248] = bytes >> 53;
    padded[249] = bytes >> 45;
    padded[250] = bytes >> 37;
    padded[251] = bytes >> 29;
    padded[252] = bytes >> 21;
    padded[253] = bytes >> 13;
    padded[254] = bytes >> 5;
    padded[255] = bytes << 3;
    blocks(h, padded, 256);
  }

  for (i = 0; i < 48; ++i)
    out[i] = h[i];

  return 0;
}

int sha512(unsigned char *out, const unsigned char *in,
           unsigned long long inlen) {
  unsigned char h[64];
  unsigned char padded[256];
  unsigned int i;
  unsigned long long bytes = inlen;

  for (i = 0; i < 64; ++i)
    h[i] = iv_512[i];

  blocks(h, in, inlen);
  in += inlen;
  inlen &= 127;
  in -= inlen;

  for (i = 0; i < inlen; ++i)
    padded[i] = in[i];
  padded[inlen] = 0x80;

  if (inlen < 112) {
    for (i = inlen + 1; i < 119; ++i)
      padded[i] = 0;
    padded[119] = bytes >> 61;
    padded[120] = bytes >> 53;
    padded[121] = bytes >> 45;
    padded[122] = bytes >> 37;
    padded[123] = bytes >> 29;
    padded[124] = bytes >> 21;
    padded[125] = bytes >> 13;
    padded[126] = bytes >> 5;
    padded[127] = bytes << 3;
    blocks(h, padded, 128);
  } else {
    for (i = inlen + 1; i < 247; ++i)
      padded[i] = 0;
    padded[247] = bytes >> 61;
    padded[248] = bytes >> 53;
    padded[249] = bytes >> 45;
    padded[250] = bytes >> 37;
    padded[251] = bytes >> 29;
    padded[252] = bytes >> 21;
    padded[253] = bytes >> 13;
    padded[254] = bytes >> 5;
    padded[255] = bytes << 3;
    blocks(h, padded, 256);
  }

  for (i = 0; i < 64; ++i)
    out[i] = h[i];

  return 0;
}