1/* public domain sha256 implementation based on fips180-3 */
2#include <ctype.h>
3#include <stdint.h>
4#include <stdio.h>
5#include <stdlib.h>
6#include <string.h>
7
8#include "../sha256.h"
9
10static uint32_t
11ror(uint32_t n, int k)
12{
13 return (n >> k) | (n << (32 - k));
14}
15#define Ch(x, y, z) (z ^ (x & (y ^ z)))
16#define Maj(x, y, z) ((x & y) | (z & (x | y)))
17#define S0(x) (ror(x, 2) ^ ror(x, 13) ^ ror(x, 22))
18#define S1(x) (ror(x, 6) ^ ror(x, 11) ^ ror(x, 25))
19#define R0(x) (ror(x, 7) ^ ror(x, 18) ^ (x >> 3))
20#define R1(x) (ror(x, 17) ^ ror(x, 19) ^ (x >> 10))
21
22static const uint32_t K[64] = {
23 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
24 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
25 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
26 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
27 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
28 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
29 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
30 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
31};
32
33static void
34processblock(struct sha256 *s, const uint8_t *buf)
35{
36 uint32_t W[64], t1, t2, a, b, c, d, e, f, g, h;
37 int i;
38
39 for (i = 0; i < 16; i++) {
40 W[i] = (uint32_t)buf[4 * i] << 24;
41 W[i] |= (uint32_t)buf[4 * i + 1] << 16;
42 W[i] |= (uint32_t)buf[4 * i + 2] << 8;
43 W[i] |= buf[4 * i + 3];
44 }
45 for (; i < 64; i++)
46 W[i] = R1(W[i - 2]) + W[i - 7] + R0(W[i - 15]) + W[i - 16];
47 a = s->h[0];
48 b = s->h[1];
49 c = s->h[2];
50 d = s->h[3];
51 e = s->h[4];
52 f = s->h[5];
53 g = s->h[6];
54 h = s->h[7];
55 for (i = 0; i < 64; i++) {
56 t1 = h + S1(e) + Ch(e, f, g) + K[i] + W[i];
57 t2 = S0(a) + Maj(a, b, c);
58 h = g;
59 g = f;
60 f = e;
61 e = d + t1;
62 d = c;
63 c = b;
64 b = a;
65 a = t1 + t2;
66 }
67 s->h[0] += a;
68 s->h[1] += b;
69 s->h[2] += c;
70 s->h[3] += d;
71 s->h[4] += e;
72 s->h[5] += f;
73 s->h[6] += g;
74 s->h[7] += h;
75}
76
77static void
78pad(struct sha256 *s)
79{
80 unsigned r = s->len % 64;
81
82 s->buf[r++] = 0x80;
83 if (r > 56) {
84 memset(s->buf + r, 0, 64 - r);
85 r = 0;
86 processblock(s, s->buf);
87 }
88 memset(s->buf + r, 0, 56 - r);
89 s->len *= 8;
90 s->buf[56] = s->len >> 56;
91 s->buf[57] = s->len >> 48;
92 s->buf[58] = s->len >> 40;
93 s->buf[59] = s->len >> 32;
94 s->buf[60] = s->len >> 24;
95 s->buf[61] = s->len >> 16;
96 s->buf[62] = s->len >> 8;
97 s->buf[63] = s->len;
98 processblock(s, s->buf);
99}
100
101void
102sha256_init(void *ctx)
103{
104 struct sha256 *s = ctx;
105 s->len = 0;
106 s->h[0] = 0x6a09e667;
107 s->h[1] = 0xbb67ae85;
108 s->h[2] = 0x3c6ef372;
109 s->h[3] = 0xa54ff53a;
110 s->h[4] = 0x510e527f;
111 s->h[5] = 0x9b05688c;
112 s->h[6] = 0x1f83d9ab;
113 s->h[7] = 0x5be0cd19;
114}
115
116void
117sha256_sum_n(void *ctx, uint8_t *md, int n)
118{
119 struct sha256 *s = ctx;
120 int i;
121
122 pad(s);
123 for (i = 0; i < n; i++) {
124 md[4 * i] = s->h[i] >> 24;
125 md[4 * i + 1] = s->h[i] >> 16;
126 md[4 * i + 2] = s->h[i] >> 8;
127 md[4 * i + 3] = s->h[i];
128 }
129}
130
131void
132sha256_sum(void *ctx, uint8_t md[SHA256_DIGEST_LENGTH])
133{
134 sha256_sum_n(ctx, md, 8);
135}
136
137void
138sha256_update(void *ctx, const void *m, unsigned long len)
139{
140 struct sha256 *s = ctx;
141 const uint8_t *p = m;
142 unsigned r = s->len % 64;
143
144 s->len += len;
145 if (r) {
146 if (len < 64 - r) {
147 memcpy(s->buf + r, p, len);
148 return;
149 }
150 memcpy(s->buf + r, p, 64 - r);
151 len -= 64 - r;
152 p += 64 - r;
153 processblock(s, s->buf);
154 }
155 for (; len >= 64; len -= 64, p += 64)
156 processblock(s, p);
157 memcpy(s->buf, p, len);
158}
