torrentd

simple torrent daemon
git clone git://git.2f30.org/torrentd
Log | Files | Refs | LICENSE

sha1.c (2963B)


      1 /* public domain sha1 implementation based on rfc3174 and libtomcrypt */
      2 #include <stdint.h>
      3 #include <string.h>
      4 
      5 #include "sha1.h"
      6 
      7 static uint32_t rol(uint32_t n, int k) { return (n << k) | (n >> (32-k)); }
      8 #define F0(b,c,d) (d ^ (b & (c ^ d)))
      9 #define F1(b,c,d) (b ^ c ^ d)
     10 #define F2(b,c,d) ((b & c) | (d & (b | c)))
     11 #define F3(b,c,d) (b ^ c ^ d)
     12 #define G0(a,b,c,d,e,i) e += rol(a,5)+F0(b,c,d)+W[i]+0x5A827999; b = rol(b,30)
     13 #define G1(a,b,c,d,e,i) e += rol(a,5)+F1(b,c,d)+W[i]+0x6ED9EBA1; b = rol(b,30)
     14 #define G2(a,b,c,d,e,i) e += rol(a,5)+F2(b,c,d)+W[i]+0x8F1BBCDC; b = rol(b,30)
     15 #define G3(a,b,c,d,e,i) e += rol(a,5)+F3(b,c,d)+W[i]+0xCA62C1D6; b = rol(b,30)
     16 
     17 static void
     18 processblock(struct sha1 *s, const uint8_t *buf)
     19 {
     20 	uint32_t W[80], a, b, c, d, e;
     21 	int i;
     22 
     23 	for (i = 0; i < 16; i++) {
     24 		W[i] = (uint32_t)buf[4*i]<<24;
     25 		W[i] |= (uint32_t)buf[4*i+1]<<16;
     26 		W[i] |= (uint32_t)buf[4*i+2]<<8;
     27 		W[i] |= buf[4*i+3];
     28 	}
     29 	for (; i < 80; i++)
     30 		W[i] = rol(W[i-3] ^ W[i-8] ^ W[i-14] ^ W[i-16], 1);
     31 	a = s->h[0];
     32 	b = s->h[1];
     33 	c = s->h[2];
     34 	d = s->h[3];
     35 	e = s->h[4];
     36 	for (i = 0; i < 20; ) {
     37 		G0(a,b,c,d,e,i++);
     38 		G0(e,a,b,c,d,i++);
     39 		G0(d,e,a,b,c,i++);
     40 		G0(c,d,e,a,b,i++);
     41 		G0(b,c,d,e,a,i++);
     42 	}
     43 	while (i < 40) {
     44 		G1(a,b,c,d,e,i++);
     45 		G1(e,a,b,c,d,i++);
     46 		G1(d,e,a,b,c,i++);
     47 		G1(c,d,e,a,b,i++);
     48 		G1(b,c,d,e,a,i++);
     49 	}
     50 	while (i < 60) {
     51 		G2(a,b,c,d,e,i++);
     52 		G2(e,a,b,c,d,i++);
     53 		G2(d,e,a,b,c,i++);
     54 		G2(c,d,e,a,b,i++);
     55 		G2(b,c,d,e,a,i++);
     56 	}
     57 	while (i < 80) {
     58 		G3(a,b,c,d,e,i++);
     59 		G3(e,a,b,c,d,i++);
     60 		G3(d,e,a,b,c,i++);
     61 		G3(c,d,e,a,b,i++);
     62 		G3(b,c,d,e,a,i++);
     63 	}
     64 	s->h[0] += a;
     65 	s->h[1] += b;
     66 	s->h[2] += c;
     67 	s->h[3] += d;
     68 	s->h[4] += e;
     69 }
     70 
     71 static void
     72 pad(struct sha1 *s)
     73 {
     74 	unsigned r = s->len % 64;
     75 
     76 	s->buf[r++] = 0x80;
     77 	if (r > 56) {
     78 		memset(s->buf + r, 0, 64 - r);
     79 		r = 0;
     80 		processblock(s, s->buf);
     81 	}
     82 	memset(s->buf + r, 0, 56 - r);
     83 	s->len *= 8;
     84 	s->buf[56] = s->len >> 56;
     85 	s->buf[57] = s->len >> 48;
     86 	s->buf[58] = s->len >> 40;
     87 	s->buf[59] = s->len >> 32;
     88 	s->buf[60] = s->len >> 24;
     89 	s->buf[61] = s->len >> 16;
     90 	s->buf[62] = s->len >> 8;
     91 	s->buf[63] = s->len;
     92 	processblock(s, s->buf);
     93 }
     94 
     95 void
     96 sha1_init(void *ctx)
     97 {
     98 	struct sha1 *s = ctx;
     99 
    100 	s->len = 0;
    101 	s->h[0] = 0x67452301;
    102 	s->h[1] = 0xEFCDAB89;
    103 	s->h[2] = 0x98BADCFE;
    104 	s->h[3] = 0x10325476;
    105 	s->h[4] = 0xC3D2E1F0;
    106 }
    107 
    108 void
    109 sha1_sum(void *ctx, uint8_t md[SHA1_DIGEST_LENGTH])
    110 {
    111 	struct sha1 *s = ctx;
    112 	int i;
    113 
    114 	pad(s);
    115 	for (i = 0; i < 5; i++) {
    116 		md[4*i] = s->h[i] >> 24;
    117 		md[4*i+1] = s->h[i] >> 16;
    118 		md[4*i+2] = s->h[i] >> 8;
    119 		md[4*i+3] = s->h[i];
    120 	}
    121 }
    122 
    123 void
    124 sha1_update(void *ctx, const void *m, unsigned long len)
    125 {
    126 	struct sha1 *s = ctx;
    127 	const uint8_t *p = m;
    128 	unsigned r = s->len % 64;
    129 
    130 	s->len += len;
    131 	if (r) {
    132 		if (len < 64 - r) {
    133 			memcpy(s->buf + r, p, len);
    134 			return;
    135 		}
    136 		memcpy(s->buf + r, p, 64 - r);
    137 		len -= 64 - r;
    138 		p += 64 - r;
    139 		processblock(s, s->buf);
    140 	}
    141 	for (; len >= 64; len -= 64, p += 64)
    142 		processblock(s, p);
    143 	memcpy(s->buf, p, len);
    144 }