1 /*
2  * Copyright (c) 2018 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/types.h>
18 #include <sha1.h>
19 #include <errno.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <limits.h>
23 
24 static int
25 parse_xdigit(uint8_t *val, const char *hex)
26 {
27 	char *ep;
28 	long lval;
29 
30 	errno = 0;
31 	lval = strtol(hex, &ep, 16);
32 	if (hex[0] == '\0' || *ep != '\0')
33 		return 0;
34 	if (errno == ERANGE && (lval == LONG_MAX || lval == LONG_MIN))
35 		return 0;
36 
37 	*val = (uint8_t)lval;
38 	return 1;
39 }
40 
41 int
42 got_parse_sha1_digest(uint8_t *digest, const char *line)
43 {
44 	uint8_t b = 0;
45 	char hex[3] = {'\0', '\0', '\0'};
46 	int i, j;
47 
48 	for (i = 0; i < SHA1_DIGEST_LENGTH; i++) {
49 		if (line[0] == '\0' || line[1] == '\0')
50 			return 0;
51 		for (j = 0; j < 2; j++) {
52 			hex[j] = *line;
53 			line++;
54 		}
55 		if (!parse_xdigit(&b, hex))
56 			return 0;
57 		digest[i] = b;
58 	}
59 
60 	return 1;
61 }
62 
63 char *
64 got_sha1_digest_to_str(const uint8_t *digest, char *buf, size_t size)
65 {
66 	char *p = buf;
67 	char hex[3];
68 	int i;
69 
70 	if (size < SHA1_DIGEST_STRING_LENGTH)
71 		return NULL;
72 
73 	for (i = 0; i < SHA1_DIGEST_LENGTH; i++) {
74 		snprintf(hex, sizeof(hex), "%.2x", digest[i]);
75 		p[0] = hex[0];
76 		p[1] = hex[1];
77 		p += 2;
78 	}
79 	p[0] = '\0';
80 
81 	return buf;
82 }