summaryrefslogtreecommitdiff
path: root/source/kit/sha256.c
blob: 3abe972e65ab5c83ce2b1f74698f7ad17a0e79d6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
#include "sha256.h"

#include <assert.h>
#include <string.h>

#define ROTLEFT(a, b) (((a) << (b)) | ((a) >> (32 - (b))))
#define ROTRIGHT(a, b) (((a) >> (b)) | ((a) << (32 - (b))))

#define CH(x, y, z) (((x) & (y)) ^ (~(x) & (z)))
#define MAJ(x, y, z) (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
#define EP0(x) (ROTRIGHT(x, 2) ^ ROTRIGHT(x, 13) ^ ROTRIGHT(x, 22))
#define EP1(x) (ROTRIGHT(x, 6) ^ ROTRIGHT(x, 11) ^ ROTRIGHT(x, 25))
#define SIG0(x) (ROTRIGHT(x, 7) ^ ROTRIGHT(x, 18) ^ ((x) >> 3))
#define SIG1(x) (ROTRIGHT(x, 17) ^ ROTRIGHT(x, 19) ^ ((x) >> 10))

static u32 kit_sha256_k[64] = {
  0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b,
  0x59f111f1, 0x923f82a4, 0xab1c5ed5, 0xd807aa98, 0x12835b01,
  0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7,
  0xc19bf174, 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
  0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da, 0x983e5152,
  0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147,
  0x06ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc,
  0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
  0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819,
  0xd6990624, 0xf40e3585, 0x106aa070, 0x19a4c116, 0x1e376c08,
  0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f,
  0x682e6ff3, 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
  0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
};

static void kit_sha256_transform(u32 *state, u8 *data) {
  assert(state != NULL);
  assert(data != NULL);

  u32 a, b, c, d, e, f, g, h, i, j, t1, t2, m[64];

  for (i = 0, j = 0; i < 16; ++i, j += 4)
    m[i] = ((u32) data[j] << 24) | ((u32) data[j + 1] << 16) |
           ((u32) data[j + 2] << 8) | ((u32) data[j + 3]);
  for (; i < 64; ++i)
    m[i] = SIG1(m[i - 2]) + m[i - 7] + SIG0(m[i - 15]) + m[i - 16];

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

  for (i = 0; i < 64; ++i) {
    t1 = h + EP1(e) + CH(e, f, g) + kit_sha256_k[i] + m[i];
    t2 = EP0(a) + MAJ(a, b, c);
    h  = g;
    g  = f;
    f  = e;
    e  = d + t1;
    d  = c;
    c  = b;
    b  = a;
    a  = t1 + t2;
  }

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

kit_sha256_hash_t kit_sha256(i64 in_size, u8 *in_data) {
  assert(in_size >= 0);
  assert(in_data != NULL);

  u32 state[8] = { 0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
                   0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19 };

  u8 data[64];

  i64 i;
  i64 datalen = 0;
  u64 bitlen  = 0;

  if (in_data != NULL)
    for (i = 0; i < in_size; ++i) {
      data[datalen] = in_data[i];
      datalen++;

      if (datalen != 64)
        continue;

      kit_sha256_transform(state, data);
      bitlen += 512;
      datalen = 0;
    }

  i = datalen;

  if (datalen < 56) {
    data[i++] = 0x80;
    while (i < 56) data[i++] = 0x00;
  } else {
    data[i++] = 0x80;
    while (i < 64) data[i++] = 0x00;

    kit_sha256_transform(state, data);
    memset(data, 0, 56);
  }

  bitlen += datalen * 8;
  data[63] = bitlen;
  data[62] = bitlen >> 8;
  data[61] = bitlen >> 16;
  data[60] = bitlen >> 24;
  data[59] = bitlen >> 32;
  data[58] = bitlen >> 40;
  data[57] = bitlen >> 48;
  data[56] = bitlen >> 56;

  kit_sha256_transform(state, data);

  kit_sha256_hash_t hash;
  memset(&hash, 0, sizeof hash);

  for (i = 0; i < 4; ++i) {
    hash.v[i]      = (state[0] >> (24 - i * 8)) & 0xff;
    hash.v[i + 4]  = (state[1] >> (24 - i * 8)) & 0xff;
    hash.v[i + 8]  = (state[2] >> (24 - i * 8)) & 0xff;
    hash.v[i + 12] = (state[3] >> (24 - i * 8)) & 0xff;
    hash.v[i + 16] = (state[4] >> (24 - i * 8)) & 0xff;
    hash.v[i + 20] = (state[5] >> (24 - i * 8)) & 0xff;
    hash.v[i + 24] = (state[6] >> (24 - i * 8)) & 0xff;
    hash.v[i + 28] = (state[7] >> (24 - i * 8)) & 0xff;
  }

  return hash;
}

#undef ROTLEFT
#undef ROTRIGHT
#undef CH
#undef MAJ
#undef EP0
#undef EP1
#undef SIG0
#undef SIG1