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 	const char hex[] = "0123456789abcdef";
75 	char *p = buf;
76 	int i;
77 
78 	for (i = 0; i < len; i++) {
79 		*p++ = hex[digest[i] >> 4];
80 		*p++ = hex[digest[i] & 0xf];
81 	}
82 	*p = '\0';
83 
84 	return buf;
85 }
86 
87 char *
88 got_sha1_digest_to_str(const uint8_t *digest, char *buf, size_t size)
89 {
90 	if (size < SHA1_DIGEST_STRING_LENGTH)
91 		return NULL;
92 	return digest_to_str(digest, SHA1_DIGEST_LENGTH, buf);
93 }
94 
95 char *
96 got_sha256_digest_to_str(const uint8_t *digest, char *buf, size_t size)
97 {
98 	if (size < SHA256_DIGEST_STRING_LENGTH)
99 		return NULL;
100 	return digest_to_str(digest, SHA256_DIGEST_LENGTH, buf);
101 }
102 
103 int
104 got_parse_hash_digest(uint8_t *digest, const char *line,
105     enum got_hash_algorithm algo)
106 {
107 	switch (algo) {
108 	case GOT_HASH_SHA1:
109 		return parse_digest(digest, SHA1_DIGEST_LENGTH, line);
110 	case GOT_HASH_SHA256:
111 		return parse_digest(digest, SHA256_DIGEST_LENGTH, line);
112 	default:
113 		return 0;
114 	}
115 }
116 
117 int
118 got_parse_object_id(struct got_object_id *id, const char *line,
119     enum got_hash_algorithm algo)
120 {
121 	memset(id, 0, sizeof(*id));
122 
123 	/* XXX: temporary until we grow got_object_id */
124 	if (algo != GOT_HASH_SHA1)
125 		return 0;
126 
127 	return got_parse_hash_digest(id->sha1, line, algo);
128 }
129 
130 void
131 got_hash_init(struct got_hash *hash, enum got_hash_algorithm algo)
132 {
133 	memset(hash, 0, sizeof(*hash));
134 	hash->algo = algo;
135 
136 	if (algo == GOT_HASH_SHA1)
137 		SHA1Init(&hash->sha1_ctx);
138 	else if (algo == GOT_HASH_SHA256)
139 		SHA256Init(&hash->sha256_ctx);
140 }
141 
142 void
143 got_hash_update(struct got_hash *hash, const void *data, size_t len)
144 {
145 	if (hash->algo == GOT_HASH_SHA1)
146 		SHA1Update(&hash->sha1_ctx, data, len);
147 	else if (hash->algo == GOT_HASH_SHA256)
148 		SHA256Update(&hash->sha256_ctx, data, len);
149 }
150 
151 void
152 got_hash_final(struct got_hash *hash, uint8_t *out)
153 {
154 	if (hash->algo == GOT_HASH_SHA1)
155 		SHA1Final(out, &hash->sha1_ctx);
156 	else if (hash->algo == GOT_HASH_SHA256)
157 		SHA256Final(out, &hash->sha256_ctx);
158 }
159 
160 void
161 got_hash_final_object_id(struct got_hash *hash, struct got_object_id *id)
162 {
163 	memset(id, 0, sizeof(*id));
164 	got_hash_final(hash, id->sha1);
165 }
166 
167 int
168 got_hash_cmp(enum got_hash_algorithm algo, uint8_t *b1, uint8_t *b2)
169 {
170 	if (algo == GOT_HASH_SHA1)
171 		return memcmp(b1, b2, SHA1_DIGEST_LENGTH);
172 	else if (algo == GOT_HASH_SHA256)
173 		return memcmp(b1, b2, SHA256_DIGEST_LENGTH);
174 	return -1;
175 }