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 <sys/queue.h>
19 
20 #include <sha2.h>
21 #include <errno.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <limits.h>
26 
27 #include "got_compat.h"
28 
29 #include "got_object.h"
30 
31 #include "got_lib_hash.h"
32 
33 int
34 got_parse_xdigit(uint8_t *val, const char *hex)
35 {
36 	char *ep;
37 	long lval;
38 
39 	errno = 0;
40 	lval = strtol(hex, &ep, 16);
41 	if (hex[0] == '\0' || *ep != '\0')
42 		return 0;
43 	if (errno == ERANGE && (lval == LONG_MAX || lval == LONG_MIN))
44 		return 0;
45 
46 	*val = (uint8_t)lval;
47 	return 1;
48 }
49 
50 static int
51 parse_digest(uint8_t *digest, int len, const char *line)
52 {
53 	uint8_t b = 0;
54 	char hex[3] = {'\0', '\0', '\0'};
55 	int i, j;
56 
57 	for (i = 0; i < len; i++) {
58 		if (line[0] == '\0' || line[1] == '\0')
59 			return 0;
60 		for (j = 0; j < 2; j++) {
61 			hex[j] = *line;
62 			line++;
63 		}
64 		if (!got_parse_xdigit(&b, hex))
65 			return 0;
66 		digest[i] = b;
67 	}
68 
69 	return 1;
70 }
71 
72 static char *
73 digest_to_str(const uint8_t *digest, int len, char *buf)
74 {
75 	char *p = buf;
76 	char hex[3];
77 	int i;
78 
79 	for (i = 0; i < len; i++) {
80 		snprintf(hex, sizeof(hex), "%.2x", digest[i]);
81 		p[0] = hex[0];
82 		p[1] = hex[1];
83 		p += 2;
84 	}
85 	p[0] = '\0';
86 
87 	return buf;
88 }
89 
90 char *
91 got_sha1_digest_to_str(const uint8_t *digest, char *buf, size_t size)
92 {
93 	if (size < SHA1_DIGEST_STRING_LENGTH)
94 		return NULL;
95 	return digest_to_str(digest, SHA1_DIGEST_LENGTH, buf);
96 }
97 
98 char *
99 got_sha256_digest_to_str(const uint8_t *digest, char *buf, size_t size)
100 {
101 	if (size < SHA256_DIGEST_STRING_LENGTH)
102 		return NULL;
103 	return digest_to_str(digest, SHA256_DIGEST_LENGTH, buf);
104 }
105 
106 int
107 got_parse_hash_digest(uint8_t *digest, const char *line,
108     enum got_hash_algorithm algo)
109 {
110 	switch (algo) {
111 	case GOT_HASH_SHA1:
112 		return parse_digest(digest, SHA1_DIGEST_LENGTH, line);
113 	case GOT_HASH_SHA256:
114 		return parse_digest(digest, SHA256_DIGEST_LENGTH, line);
115 	default:
116 		return 0;
117 	}
118 }
119 
120 int
121 got_parse_object_id(struct got_object_id *id, const char *line,
122     enum got_hash_algorithm algo)
123 {
124 	memset(id, 0, sizeof(*id));
125 
126 	/* XXX: temporary until we grow got_object_id */
127 	if (algo != GOT_HASH_SHA1)
128 		return 0;
129 
130 	return got_parse_hash_digest(id->sha1, line, algo);
131 }