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 <sha1.h>
21 #include <sha2.h>
22 #include <errno.h>
23 #include <stdio.h>
24 #include <stdlib.h>
25 #include <limits.h>
26 
27 #include "got_lib_hash.h"
28 
29 #include "got_object.h"
30 
31 int
32 got_parse_xdigit(uint8_t *val, const char *hex)
33 {
34 	char *ep;
35 	long lval;
36 
37 	errno = 0;
38 	lval = strtol(hex, &ep, 16);
39 	if (hex[0] == '\0' || *ep != '\0')
40 		return 0;
41 	if (errno == ERANGE && (lval == LONG_MAX || lval == LONG_MIN))
42 		return 0;
43 
44 	*val = (uint8_t)lval;
45 	return 1;
46 }
47 
48 int
49 got_parse_sha1_digest(uint8_t *digest, const char *line)
50 {
51 	uint8_t b = 0;
52 	char hex[3] = {'\0', '\0', '\0'};
53 	int i, j;
54 
55 	for (i = 0; i < SHA1_DIGEST_LENGTH; i++) {
56 		if (line[0] == '\0' || line[1] == '\0')
57 			return 0;
58 		for (j = 0; j < 2; j++) {
59 			hex[j] = *line;
60 			line++;
61 		}
62 		if (!got_parse_xdigit(&b, hex))
63 			return 0;
64 		digest[i] = b;
65 	}
66 
67 	return 1;
68 }
69 
70 char *
71 got_sha1_digest_to_str(const uint8_t *digest, char *buf, size_t size)
72 {
73 	char *p = buf;
74 	char hex[3];
75 	int i;
76 
77 	if (size < SHA1_DIGEST_STRING_LENGTH)
78 		return NULL;
79 
80 	for (i = 0; i < SHA1_DIGEST_LENGTH; i++) {
81 		snprintf(hex, sizeof(hex), "%.2x", digest[i]);
82 		p[0] = hex[0];
83 		p[1] = hex[1];
84 		p += 2;
85 	}
86 	p[0] = '\0';
87 
88 	return buf;
89 }
90 
91 int
92 got_parse_sha256_digest(uint8_t *digest, const char *line)
93 {
94 	uint8_t b = 0;
95 	char hex[3] = {'\0', '\0', '\0'};
96 	int i, j;
97 
98 	for (i = 0; i < SHA256_DIGEST_LENGTH; i++) {
99 		if (line[0] == '\0' || line[1] == '\0')
100 			return 0;
101 		for (j = 0; j < 2; j++) {
102 			hex[j] = *line;
103 			line++;
104 		}
105 		if (!got_parse_xdigit(&b, hex))
106 			return 0;
107 		digest[i] = b;
108 	}
109 
110 	return 1;
111 }
112 
113 char *
114 got_sha256_digest_to_str(const uint8_t *digest, char *buf, size_t size)
115 {
116 	char *p = buf;
117 	char hex[3];
118 	int i;
119 
120 	if (size < SHA256_DIGEST_STRING_LENGTH)
121 		return NULL;
122 
123 	for (i = 0; i < SHA256_DIGEST_LENGTH; i++) {
124 		snprintf(hex, sizeof(hex), "%.2x", digest[i]);
125 		p[0] = hex[0];
126 		p[1] = hex[1];
127 		p += 2;
128 	}
129 	p[0] = '\0';
130 
131 	return buf;
132 }
133 
134 int
135 got_parse_hash_digest(uint8_t *digest, const char *line, int algo, size_t *len)
136 {
137 	if (algo == GOT_HASH_SHA256) {
138 		if (len)
139 			*len = SHA256_DIGEST_STRING_LENGTH;
140 		return got_parse_sha256_digest(digest, line);
141 	} else if (algo == GOT_HASH_SHA1) {
142 		if (len)
143 			*len = SHA1_DIGEST_STRING_LENGTH;
144 		return got_parse_sha1_digest(digest, line);
145 	}
146 
147 	return 0;
148 }