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 <string.h>
26 #include <limits.h>
27 
28 #include "got_object.h"
29 
30 #include "got_lib_hash.h"
31 
32 int
33 got_parse_xdigit(uint8_t *val, const char *hex)
34 {
35 	char *ep;
36 	long lval;
37 
38 	errno = 0;
39 	lval = strtol(hex, &ep, 16);
40 	if (hex[0] == '\0' || *ep != '\0')
41 		return 0;
42 	if (errno == ERANGE && (lval == LONG_MAX || lval == LONG_MIN))
43 		return 0;
44 
45 	*val = (uint8_t)lval;
46 	return 1;
47 }
48 
49 static int
50 parse_digest(uint8_t *digest, int len, const char *line)
51 {
52 	uint8_t b = 0;
53 	char hex[3] = {'\0', '\0', '\0'};
54 	int i, j;
55 
56 	for (i = 0; i < len; i++) {
57 		if (line[0] == '\0' || line[1] == '\0')
58 			return 0;
59 		for (j = 0; j < 2; j++) {
60 			hex[j] = *line;
61 			line++;
62 		}
63 		if (!got_parse_xdigit(&b, hex))
64 			return 0;
65 		digest[i] = b;
66 	}
67 
68 	return 1;
69 }
70 
71 static char *
72 digest_to_str(const uint8_t *digest, int len, char *buf)
73 {
74 	char *p = buf;
75 	char hex[3];
76 	int i;
77 
78 	for (i = 0; i < len; i++) {
79 		snprintf(hex, sizeof(hex), "%.2x", digest[i]);
80 		p[0] = hex[0];
81 		p[1] = hex[1];
82 		p += 2;
83 	}
84 	p[0] = '\0';
85 
86 	return buf;
87 }
88 
89 char *
90 got_sha1_digest_to_str(const uint8_t *digest, char *buf, size_t size)
91 {
92 	if (size < SHA1_DIGEST_STRING_LENGTH)
93 		return NULL;
94 	return digest_to_str(digest, SHA1_DIGEST_LENGTH, buf);
95 }
96 
97 char *
98 got_sha256_digest_to_str(const uint8_t *digest, char *buf, size_t size)
99 {
100 	if (size < SHA256_DIGEST_STRING_LENGTH)
101 		return NULL;
102 	return digest_to_str(digest, SHA256_DIGEST_LENGTH, buf);
103 }
104 
105 int
106 got_parse_hash_digest(uint8_t *digest, const char *line,
107     enum got_hash_algorithm algo)
108 {
109 	switch (algo) {
110 	case GOT_HASH_SHA1:
111 		return parse_digest(digest, SHA1_DIGEST_LENGTH, line);
112 	case GOT_HASH_SHA256:
113 		return parse_digest(digest, SHA256_DIGEST_LENGTH, line);
114 	default:
115 		return 0;
116 	}
117 }
118 
119 int
120 got_parse_object_id(struct got_object_id *id, const char *line,
121     enum got_hash_algorithm algo)
122 {
123 	memset(id, 0, sizeof(*id));
124 
125 	/* XXX: temporary until we grow got_object_id */
126 	if (algo != GOT_HASH_SHA1)
127 		return 0;
128 
129 	return got_parse_hash_digest(id->sha1, line, algo);
130 }
131 
132 void
133 got_hash_init(struct got_hash *hash, enum got_hash_algorithm algo)
134 {
135 	memset(hash, 0, sizeof(*hash));
136 	hash->algo = algo;
137 
138 	if (algo == GOT_HASH_SHA1)
139 		SHA1Init(&hash->sha1_ctx);
140 	else if (algo == GOT_HASH_SHA256)
141 		SHA256Init(&hash->sha256_ctx);
142 }
143 
144 void
145 got_hash_update(struct got_hash *hash, const void *data, size_t len)
146 {
147 	if (hash->algo == GOT_HASH_SHA1)
148 		SHA1Update(&hash->sha1_ctx, data, len);
149 	else if (hash->algo == GOT_HASH_SHA256)
150 		SHA256Update(&hash->sha256_ctx, data, len);
151 }
152 
153 void
154 got_hash_final(struct got_hash *hash, uint8_t *out)
155 {
156 	if (hash->algo == GOT_HASH_SHA1)
157 		SHA1Final(out, &hash->sha1_ctx);
158 	else if (hash->algo == GOT_HASH_SHA256)
159 		SHA256Final(out, &hash->sha256_ctx);
160 }
161 
162 void
163 got_hash_final_object_id(struct got_hash *hash, struct got_object_id *id)
164 {
165 	memset(id, 0, sizeof(*id));
166 	got_hash_final(hash, id->sha1);
167 }
168 
169 int
170 got_hash_cmp(enum got_hash_algorithm algo, uint8_t *b1, uint8_t *b2)
171 {
172 	if (algo == GOT_HASH_SHA1)
173 		return memcmp(b1, b2, SHA1_DIGEST_LENGTH);
174 	else if (algo == GOT_HASH_SHA256)
175 		return memcmp(b1, b2, SHA256_DIGEST_LENGTH);
176 	return -1;
177 }