xref: /freebsd/crypto/openssh/digest-libc.c (revision 716fd348) 
1 /* $OpenBSD: digest-libc.c,v 1.7 2020/02/26 13:40:09 jsg Exp $ */
2 /*
3  * Copyright (c) 2013 Damien Miller <djm@mindrot.org>
4  * Copyright (c) 2014 Markus Friedl.  All rights reserved.
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include "includes.h"
20 
21 #ifndef WITH_OPENSSL
22 
23 #include <sys/types.h>
24 #include <limits.h>
25 #include <stdlib.h>
26 #include <string.h>
27 
28 #if 0
29 #include <md5.h>
30 #include <rmd160.h>
31 #endif
32 #ifdef HAVE_SHA1_H
33 #include <sha1.h>
34 #endif
35 #ifdef HAVE_SHA2_H
36 #include <sha2.h>
37 #endif
38 
39 #if !defined(SHA256_BLOCK_LENGTH) && defined(SHA256_HMAC_BLOCK_SIZE)
40 #define SHA256_BLOCK_LENGTH SHA256_HMAC_BLOCK_SIZE
41 #endif
42 #if !defined(SHA384_BLOCK_LENGTH) && defined(SHA512_HMAC_BLOCK_SIZE)
43 #define SHA384_BLOCK_LENGTH SHA512_HMAC_BLOCK_SIZE
44 #endif
45 #if !defined(SHA512_BLOCK_LENGTH) && defined(SHA512_HMAC_BLOCK_SIZE)
46 #define SHA512_BLOCK_LENGTH SHA512_HMAC_BLOCK_SIZE
47 #endif
48 
49 #include "ssherr.h"
50 #include "sshbuf.h"
51 #include "digest.h"
52 
53 typedef void md_init_fn(void *mdctx);
54 typedef void md_update_fn(void *mdctx, const u_int8_t *m, size_t mlen);
55 typedef void md_final_fn(u_int8_t[], void *mdctx);
56 
57 struct ssh_digest_ctx {
58 	int alg;
59 	void *mdctx;
60 };
61 
62 struct ssh_digest {
63 	int id;
64 	const char *name;
65 	size_t block_len;
66 	size_t digest_len;
67 	size_t ctx_len;
68 	md_init_fn *md_init;
69 	md_update_fn *md_update;
70 	md_final_fn *md_final;
71 };
72 
73 /* NB. Indexed directly by algorithm number */
74 const struct ssh_digest digests[SSH_DIGEST_MAX] = {
75 	{
76 		SSH_DIGEST_MD5,
77 		"MD5",
78 		MD5_BLOCK_LENGTH,
79 		MD5_DIGEST_LENGTH,
80 		sizeof(MD5_CTX),
81 		(md_init_fn *) MD5Init,
82 		(md_update_fn *) MD5Update,
83 		(md_final_fn *) MD5Final
84 	},
85 	{
86 		SSH_DIGEST_SHA1,
87 		"SHA1",
88 		SHA1_BLOCK_LENGTH,
89 		SHA1_DIGEST_LENGTH,
90 		sizeof(SHA1_CTX),
91 		(md_init_fn *) SHA1Init,
92 		(md_update_fn *) SHA1Update,
93 		(md_final_fn *) SHA1Final
94 	},
95 	{
96 		SSH_DIGEST_SHA256,
97 		"SHA256",
98 		SHA256_BLOCK_LENGTH,
99 		SHA256_DIGEST_LENGTH,
100 		sizeof(SHA2_CTX),
101 		(md_init_fn *) SHA256Init,
102 		(md_update_fn *) SHA256Update,
103 		(md_final_fn *) SHA256Final
104 	},
105 	{
106 		SSH_DIGEST_SHA384,
107 		"SHA384",
108 		SHA384_BLOCK_LENGTH,
109 		SHA384_DIGEST_LENGTH,
110 		sizeof(SHA2_CTX),
111 		(md_init_fn *) SHA384Init,
112 		(md_update_fn *) SHA384Update,
113 		(md_final_fn *) SHA384Final
114 	},
115 	{
116 		SSH_DIGEST_SHA512,
117 		"SHA512",
118 		SHA512_BLOCK_LENGTH,
119 		SHA512_DIGEST_LENGTH,
120 		sizeof(SHA2_CTX),
121 		(md_init_fn *) SHA512Init,
122 		(md_update_fn *) SHA512Update,
123 		(md_final_fn *) SHA512Final
124 	}
125 };
126 
127 static const struct ssh_digest *
128 ssh_digest_by_alg(int alg)
129 {
130 	if (alg < 0 || alg >= SSH_DIGEST_MAX)
131 		return NULL;
132 	if (digests[alg].id != alg) /* sanity */
133 		return NULL;
134 	return &(digests[alg]);
135 }
136 
137 int
138 ssh_digest_alg_by_name(const char *name)
139 {
140 	int alg;
141 
142 	for (alg = 0; alg < SSH_DIGEST_MAX; alg++) {
143 		if (strcasecmp(name, digests[alg].name) == 0)
144 			return digests[alg].id;
145 	}
146 	return -1;
147 }
148 
149 const char *
150 ssh_digest_alg_name(int alg)
151 {
152 	const struct ssh_digest *digest = ssh_digest_by_alg(alg);
153 
154 	return digest == NULL ? NULL : digest->name;
155 }
156 
157 size_t
158 ssh_digest_bytes(int alg)
159 {
160 	const struct ssh_digest *digest = ssh_digest_by_alg(alg);
161 
162 	return digest == NULL ? 0 : digest->digest_len;
163 }
164 
165 size_t
166 ssh_digest_blocksize(struct ssh_digest_ctx *ctx)
167 {
168 	const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg);
169 
170 	return digest == NULL ? 0 : digest->block_len;
171 }
172 
173 struct ssh_digest_ctx *
174 ssh_digest_start(int alg)
175 {
176 	const struct ssh_digest *digest = ssh_digest_by_alg(alg);
177 	struct ssh_digest_ctx *ret;
178 
179 	if (digest == NULL || (ret = calloc(1, sizeof(*ret))) == NULL)
180 		return NULL;
181 	if ((ret->mdctx = calloc(1, digest->ctx_len)) == NULL) {
182 		free(ret);
183 		return NULL;
184 	}
185 	ret->alg = alg;
186 	digest->md_init(ret->mdctx);
187 	return ret;
188 }
189 
190 int
191 ssh_digest_copy_state(struct ssh_digest_ctx *from, struct ssh_digest_ctx *to)
192 {
193 	const struct ssh_digest *digest = ssh_digest_by_alg(from->alg);
194 
195 	if (digest == NULL || from->alg != to->alg)
196 		return SSH_ERR_INVALID_ARGUMENT;
197 	memcpy(to->mdctx, from->mdctx, digest->ctx_len);
198 	return 0;
199 }
200 
201 int
202 ssh_digest_update(struct ssh_digest_ctx *ctx, const void *m, size_t mlen)
203 {
204 	const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg);
205 
206 	if (digest == NULL)
207 		return SSH_ERR_INVALID_ARGUMENT;
208 	digest->md_update(ctx->mdctx, m, mlen);
209 	return 0;
210 }
211 
212 int
213 ssh_digest_update_buffer(struct ssh_digest_ctx *ctx, const struct sshbuf *b)
214 {
215 	return ssh_digest_update(ctx, sshbuf_ptr(b), sshbuf_len(b));
216 }
217 
218 int
219 ssh_digest_final(struct ssh_digest_ctx *ctx, u_char *d, size_t dlen)
220 {
221 	const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg);
222 
223 	if (digest == NULL)
224 		return SSH_ERR_INVALID_ARGUMENT;
225 	if (dlen > UINT_MAX)
226 		return SSH_ERR_INVALID_ARGUMENT;
227 	if (dlen < digest->digest_len) /* No truncation allowed */
228 		return SSH_ERR_INVALID_ARGUMENT;
229 	digest->md_final(d, ctx->mdctx);
230 	return 0;
231 }
232 
233 void
234 ssh_digest_free(struct ssh_digest_ctx *ctx)
235 {
236 	const struct ssh_digest *digest;
237 
238 	if (ctx != NULL) {
239 		digest = ssh_digest_by_alg(ctx->alg);
240 		if (digest) {
241 			explicit_bzero(ctx->mdctx, digest->ctx_len);
242 			free(ctx->mdctx);
243 			freezero(ctx, sizeof(*ctx));
244 		}
245 	}
246 }
247 
248 int
249 ssh_digest_memory(int alg, const void *m, size_t mlen, u_char *d, size_t dlen)
250 {
251 	struct ssh_digest_ctx *ctx = ssh_digest_start(alg);
252 
253 	if (ctx == NULL)
254 		return SSH_ERR_INVALID_ARGUMENT;
255 	if (ssh_digest_update(ctx, m, mlen) != 0 ||
256 	    ssh_digest_final(ctx, d, dlen) != 0)
257 		return SSH_ERR_INVALID_ARGUMENT;
258 	ssh_digest_free(ctx);
259 	return 0;
260 }
261 
262 int
263 ssh_digest_buffer(int alg, const struct sshbuf *b, u_char *d, size_t dlen)
264 {
265 	return ssh_digest_memory(alg, sshbuf_ptr(b), sshbuf_len(b), d, dlen);
266 }
267 #endif /* !WITH_OPENSSL */
268