sha256.c (3600B)
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 10 static 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 18 static const uint32_t K[64] = { 19 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5, 20 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, 21 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da, 22 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967, 23 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 24 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070, 25 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3, 26 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2 27 }; 28 29 static void 30 processblock(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 73 static void 74 pad(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 97 void 98 sha256_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 } 111 112 void 113 sha256_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 } 126 127 void 128 sha256_sum(void *ctx, uint8_t md[SHA256_DIGEST_LENGTH]) 129 { 130 sha256_sum_n(ctx, md, 8); 131 } 132 133 void 134 sha256_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 }