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 ror(uint32_t n, int k) { return (n >> k) | (n << (32-k)); }
11#define Ch(x,y,z) (z ^ (x & (y ^ z)))
12#define Maj(x,y,z) ((x & y) | (z & (x | y)))
13#define S0(x) (ror(x,2) ^ ror(x,13) ^ ror(x,22))
14#define S1(x) (ror(x,6) ^ ror(x,11) ^ ror(x,25))
15#define R0(x) (ror(x,7) ^ ror(x,18) ^ (x>>3))
16#define R1(x) (ror(x,17) ^ ror(x,19) ^ (x>>10))
17
18static const uint32_t K[64] = {
190x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
200xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
210xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
220x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
230x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
240xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
250x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
260x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
27};
28
29static void
30processblock(struct sha256 *s, const uint8_t *buf)
31{
32 uint32_t W[64], t1, t2, a, b, c, d, e, f, g, h;
33 int i;
34
35 for (i = 0; i < 16; i++) {
36 W[i] = (uint32_t)buf[4*i]<<24;
37 W[i] |= (uint32_t)buf[4*i+1]<<16;
38 W[i] |= (uint32_t)buf[4*i+2]<<8;
39 W[i] |= buf[4*i+3];
40 }
41 for (; i < 64; i++)
42 W[i] = R1(W[i-2]) + W[i-7] + R0(W[i-15]) + W[i-16];
43 a = s->h[0];
44 b = s->h[1];
45 c = s->h[2];
46 d = s->h[3];
47 e = s->h[4];
48 f = s->h[5];
49 g = s->h[6];
50 h = s->h[7];
51 for (i = 0; i < 64; i++) {
52 t1 = h + S1(e) + Ch(e,f,g) + K[i] + W[i];
53 t2 = S0(a) + Maj(a,b,c);
54 h = g;
55 g = f;
56 f = e;
57 e = d + t1;
58 d = c;
59 c = b;
60 b = a;
61 a = t1 + t2;
62 }
63 s->h[0] += a;
64 s->h[1] += b;
65 s->h[2] += c;
66 s->h[3] += d;
67 s->h[4] += e;
68 s->h[5] += f;
69 s->h[6] += g;
70 s->h[7] += h;
71}
72
73static void
74pad(struct sha256 *s)
75{
76 unsigned r = s->len % 64;
77
78 s->buf[r++] = 0x80;
79 if (r > 56) {
80 memset(s->buf + r, 0, 64 - r);
81 r = 0;
82 processblock(s, s->buf);
83 }
84 memset(s->buf + r, 0, 56 - r);
85 s->len *= 8;
86 s->buf[56] = s->len >> 56;
87 s->buf[57] = s->len >> 48;
88 s->buf[58] = s->len >> 40;
89 s->buf[59] = s->len >> 32;
90 s->buf[60] = s->len >> 24;
91 s->buf[61] = s->len >> 16;
92 s->buf[62] = s->len >> 8;
93 s->buf[63] = s->len;
94 processblock(s, s->buf);
95}
96
97void
98sha256_init(void *ctx)
99{
100 struct sha256 *s = ctx;
101 s->len = 0;
102 s->h[0] = 0x6a09e667;
103 s->h[1] = 0xbb67ae85;
104 s->h[2] = 0x3c6ef372;
105 s->h[3] = 0xa54ff53a;
106 s->h[4] = 0x510e527f;
107 s->h[5] = 0x9b05688c;
108 s->h[6] = 0x1f83d9ab;
109 s->h[7] = 0x5be0cd19;
110}
111
112void
113sha256_sum_n(void *ctx, uint8_t *md, int n)
114{
115 struct sha256 *s = ctx;
116 int i;
117
118 pad(s);
119 for (i = 0; i < n; i++) {
120 md[4*i] = s->h[i] >> 24;
121 md[4*i+1] = s->h[i] >> 16;
122 md[4*i+2] = s->h[i] >> 8;
123 md[4*i+3] = s->h[i];
124 }
125}
126
127void
128sha256_sum(void *ctx, uint8_t md[SHA256_DIGEST_LENGTH])
129{
130 sha256_sum_n(ctx, md, 8);
131}
132
133void
134sha256_update(void *ctx, const void *m, unsigned long len)
135{
136 struct sha256 *s = ctx;
137 const uint8_t *p = m;
138 unsigned r = s->len % 64;
139
140 s->len += len;
141 if (r) {
142 if (len < 64 - r) {
143 memcpy(s->buf + r, p, len);
144 return;
145 }
146 memcpy(s->buf + r, p, 64 - r);
147 len -= 64 - r;
148 p += 64 - r;
149 processblock(s, s->buf);
150 }
151 for (; len >= 64; len -= 64, p += 64)
152 processblock(s, p);
153 memcpy(s->buf, p, len);
154}
