1 /*
2 * public domain sha256 crypt implementation
3 *
4 * original sha crypt design: http://people.redhat.com/drepper/SHA-crypt.txt
5 * in this implementation at least 32bit int is assumed,
6 * key length is limited, the $5$ prefix is mandatory, '\n' and ':' is rejected
7 * in the salt and rounds= setting must contain a valid iteration count,
8 * on error "*" is returned.
9 */
10 #include <ctype.h>
11 #include <stdlib.h>
12 #include <stdio.h>
13 #include <string.h>
14 #include <stdint.h>
15
16 #include "sha256.h"
17
18 /* public domain sha256 implementation based on fips180-3 */
19
20 struct sha256 {
21 uint64_t len; /* processed message length */
22 uint32_t h[8]; /* hash state */
23 uint8_t buf[64]; /* message block buffer */
24 };
25
26 static uint32_t ror(uint32_t n, int k) { return (n >> k) | (n << (32-k)); }
27 #define Ch(x,y,z) (z ^ (x & (y ^ z)))
28 #define Maj(x,y,z) ((x & y) | (z & (x | y)))
29 #define S0(x) (ror(x,2) ^ ror(x,13) ^ ror(x,22))
30 #define S1(x) (ror(x,6) ^ ror(x,11) ^ ror(x,25))
31 #define R0(x) (ror(x,7) ^ ror(x,18) ^ (x>>3))
32 #define R1(x) (ror(x,17) ^ ror(x,19) ^ (x>>10))
33
34 static const uint32_t K[64] = {
35 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
36 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
37 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
38 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
39 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
40 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
41 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
42 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
43 };
44
45 static void processblock(struct sha256 *s, const uint8_t *buf)
46 {
47 uint32_t W[64], t1, t2, a, b, c, d, e, f, g, h;
48 int i;
49
50 for (i = 0; i < 16; i++) {
51 W[i] = (uint32_t)buf[4*i]<<24;
52 W[i] |= (uint32_t)buf[4*i+1]<<16;
53 W[i] |= (uint32_t)buf[4*i+2]<<8;
54 W[i] |= buf[4*i+3];
55 }
56 for (; i < 64; i++)
57 W[i] = R1(W[i-2]) + W[i-7] + R0(W[i-15]) + W[i-16];
58 a = s->h[0];
59 b = s->h[1];
60 c = s->h[2];
61 d = s->h[3];
62 e = s->h[4];
63 f = s->h[5];
64 g = s->h[6];
65 h = s->h[7];
66 for (i = 0; i < 64; i++) {
67 t1 = h + S1(e) + Ch(e,f,g) + K[i] + W[i];
68 t2 = S0(a) + Maj(a,b,c);
69 h = g;
70 g = f;
71 f = e;
72 e = d + t1;
73 d = c;
74 c = b;
75 b = a;
76 a = t1 + t2;
77 }
78 s->h[0] += a;
79 s->h[1] += b;
80 s->h[2] += c;
81 s->h[3] += d;
82 s->h[4] += e;
83 s->h[5] += f;
84 s->h[6] += g;
85 s->h[7] += h;
86 }
87
88 static void pad(struct sha256 *s)
89 {
90 unsigned r = s->len % 64;
91
92 s->buf[r++] = 0x80;
93 if (r > 56) {
94 memset(s->buf + r, 0, 64 - r);
95 r = 0;
96 processblock(s, s->buf);
97 }
98 memset(s->buf + r, 0, 56 - r);
99 s->len *= 8;
100 s->buf[56] = s->len >> 56;
101 s->buf[57] = s->len >> 48;
102 s->buf[58] = s->len >> 40;
103 s->buf[59] = s->len >> 32;
104 s->buf[60] = s->len >> 24;
105 s->buf[61] = s->len >> 16;
106 s->buf[62] = s->len >> 8;
107 s->buf[63] = s->len;
108 processblock(s, s->buf);
109 }
110
111 static void sha256_init(struct sha256 *s)
112 {
113 s->len = 0;
114 s->h[0] = 0x6a09e667;
115 s->h[1] = 0xbb67ae85;
116 s->h[2] = 0x3c6ef372;
117 s->h[3] = 0xa54ff53a;
118 s->h[4] = 0x510e527f;
119 s->h[5] = 0x9b05688c;
120 s->h[6] = 0x1f83d9ab;
121 s->h[7] = 0x5be0cd19;
122 }
123
124 static void sha256_sum(struct sha256 *s, uint8_t *md)
125 {
126 int i;
127
128 pad(s);
129 for (i = 0; i < 8; i++) {
130 md[4*i] = s->h[i] >> 24;
131 md[4*i+1] = s->h[i] >> 16;
132 md[4*i+2] = s->h[i] >> 8;
133 md[4*i+3] = s->h[i];
134 }
135 }
136
137 static void sha256_update(struct sha256 *s, const void *m, unsigned long len)
138 {
139 const uint8_t *p = m;
140 unsigned r = s->len % 64;
141
142 s->len += len;
143 if (r) {
144 if (len < 64 - r) {
145 memcpy(s->buf + r, p, len);
146 return;
147 }
148 memcpy(s->buf + r, p, 64 - r);
149 len -= 64 - r;
150 p += 64 - r;
151 processblock(s, s->buf);
152 }
153 for (; len >= 64; len -= 64, p += 64)
154 processblock(s, p);
155 memcpy(s->buf, p, len);
156 }
157
158 void ul_SHA256(unsigned char hash_out[UL_SHA256LENGTH], const unsigned char *str, size_t len) {
159 struct sha256 state = {};
160 sha256_init(&state);
161 sha256_update(&state, str, len);
162 sha256_sum(&state, hash_out);
163 }