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 int
50 got_parse_sha1_digest(uint8_t *digest, 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 < SHA1_DIGEST_LENGTH; 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 char *
72 got_sha1_digest_to_str(const uint8_t *digest, char *buf, size_t size)
73 {
74 	char *p = buf;
75 	char hex[3];
76 	int i;
77 
78 	if (size < SHA1_DIGEST_STRING_LENGTH)
79 		return NULL;
80 
81 	for (i = 0; i < SHA1_DIGEST_LENGTH; i++) {
82 		snprintf(hex, sizeof(hex), "%.2x", digest[i]);
83 		p[0] = hex[0];
84 		p[1] = hex[1];
85 		p += 2;
86 	}
87 	p[0] = '\0';
88 
89 	return buf;
90 }
91 
92 int
93 got_parse_sha256_digest(uint8_t *digest, const char *line)
94 {
95 	uint8_t b = 0;
96 	char hex[3] = {'\0', '\0', '\0'};
97 	int i, j;
98 
99 	for (i = 0; i < SHA256_DIGEST_LENGTH; i++) {
100 		if (line[0] == '\0' || line[1] == '\0')
101 			return 0;
102 		for (j = 0; j < 2; j++) {
103 			hex[j] = *line;
104 			line++;
105 		}
106 		if (!got_parse_xdigit(&b, hex))
107 			return 0;
108 		digest[i] = b;
109 	}
110 
111 	return 1;
112 }
113 
114 char *
115 got_sha256_digest_to_str(const uint8_t *digest, char *buf, size_t size)
116 {
117 	char *p = buf;
118 	char hex[3];
119 	int i;
120 
121 	if (size < SHA256_DIGEST_STRING_LENGTH)
122 		return NULL;
123 
124 	for (i = 0; i < SHA256_DIGEST_LENGTH; i++) {
125 		snprintf(hex, sizeof(hex), "%.2x", digest[i]);
126 		p[0] = hex[0];
127 		p[1] = hex[1];
128 		p += 2;
129 	}
130 	p[0] = '\0';
131 
132 	return buf;
133 }
134 
135 int
136 got_parse_hash_digest(uint8_t *digest, const char *line,
137     enum got_hash_algorithm algo)
138 {
139 	switch (algo) {
140 	case GOT_HASH_SHA1:
141 		return got_parse_sha1_digest(digest, line);
142 	case GOT_HASH_SHA256:
143 		return got_parse_sha256_digest(digest, line);
144 	default:
145 		return 0;
146 	}
147 }
148 
149 char *
150 got_hash_digest_to_str(const uint8_t *digest, char *buf, size_t size,
151     enum got_hash_algorithm algo)
152 {
153 	switch (algo) {
154 	case GOT_HASH_SHA1:
155 		return got_sha1_digest_to_str(digest, buf, size);
156 	case GOT_HASH_SHA256:
157 		return got_sha256_digest_to_str(digest, buf, size);
158 	default:
159 		return NULL;
160 	}
161 }
162 
163 size_t
164 got_hash_digest_length(enum got_hash_algorithm algo)
165 {
166 	switch (algo) {
167 	case GOT_HASH_SHA1:
168 		return SHA1_DIGEST_LENGTH;
169 	case GOT_HASH_SHA256:
170 		return SHA256_DIGEST_LENGTH;
171 	default:
172 		return 0;
173 	}
174 }
175 
176 size_t
177 got_hash_digest_string_length(enum got_hash_algorithm algo)
178 {
179 	switch (algo) {
180 	case GOT_HASH_SHA1:
181 		return SHA1_DIGEST_STRING_LENGTH;
182 	case GOT_HASH_SHA256:
183 		return SHA256_DIGEST_STRING_LENGTH;
184 	default:
185 		return 0;
186 	}
187 }
188 
189 void
190 got_hash_init(struct got_hash *hash, enum got_hash_algorithm algo)
191 {
192 	memset(hash, 0, sizeof(*hash));
193 	hash->algo = algo;
194 
195 	if (algo == GOT_HASH_SHA1)
196 		SHA1Init(&hash->sha1_ctx);
197 	else if (algo == GOT_HASH_SHA256)
198 		SHA256Init(&hash->sha256_ctx);
199 }
200 
201 void
202 got_hash_update(struct got_hash *hash, const void *data, size_t len)
203 {
204 	if (hash->algo == GOT_HASH_SHA1)
205 		SHA1Update(&hash->sha1_ctx, data, len);
206 	else if (hash->algo == GOT_HASH_SHA256)
207 		SHA256Update(&hash->sha256_ctx, data, len);
208 }
209 
210 void
211 got_hash_final(struct got_hash *hash, uint8_t *out)
212 {
213 	if (hash->algo == GOT_HASH_SHA1)
214 		SHA1Final(out, &hash->sha1_ctx);
215 	else if (hash->algo == GOT_HASH_SHA256)
216 		SHA256Final(out, &hash->sha256_ctx);
217 }
218 
219 int
220 got_hash_cmp(struct got_hash *hash, uint8_t *orig, uint8_t *target)
221 {
222 	if (hash->algo == GOT_HASH_SHA1)
223 		return memcmp(orig, target, SHA1_DIGEST_LENGTH);
224 	else if (hash->algo == GOT_HASH_SHA256)
225 		return memcmp(orig, target, SHA256_DIGEST_LENGTH);
226 	return -1;
227 }