sbase

suckless unix tools
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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 }