xref: /freebsd/crypto/openssh/digest-libc.c (revision 0957b409) 
1 /* $OpenBSD: digest-libc.c,v 1.6 2017/05/08 22:57:38 djm 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 #include <sha1.h>
32 #include <sha2.h>
33 #endif
34 
35 #include "ssherr.h"
36 #include "sshbuf.h"
37 #include "digest.h"
38 
39 typedef void md_init_fn(void *mdctx);
40 typedef void md_update_fn(void *mdctx, const u_int8_t *m, size_t mlen);
41 typedef void md_final_fn(u_int8_t[], void *mdctx);
42 
43 struct ssh_digest_ctx {
44 	int alg;
45 	void *mdctx;
46 };
47 
48 struct ssh_digest {
49 	int id;
50 	const char *name;
51 	size_t block_len;
52 	size_t digest_len;
53 	size_t ctx_len;
54 	md_init_fn *md_init;
55 	md_update_fn *md_update;
56 	md_final_fn *md_final;
57 };
58 
59 /* NB. Indexed directly by algorithm number */
60 const struct ssh_digest digests[SSH_DIGEST_MAX] = {
61 	{
62 		SSH_DIGEST_MD5,
63 		"MD5",
64 		MD5_BLOCK_LENGTH,
65 		MD5_DIGEST_LENGTH,
66 		sizeof(MD5_CTX),
67 		(md_init_fn *) MD5Init,
68 		(md_update_fn *) MD5Update,
69 		(md_final_fn *) MD5Final
70 	},
71 	{
72 		SSH_DIGEST_SHA1,
73 		"SHA1",
74 		SHA1_BLOCK_LENGTH,
75 		SHA1_DIGEST_LENGTH,
76 		sizeof(SHA1_CTX),
77 		(md_init_fn *) SHA1Init,
78 		(md_update_fn *) SHA1Update,
79 		(md_final_fn *) SHA1Final
80 	},
81 	{
82 		SSH_DIGEST_SHA256,
83 		"SHA256",
84 		SHA256_BLOCK_LENGTH,
85 		SHA256_DIGEST_LENGTH,
86 		sizeof(SHA256_CTX),
87 		(md_init_fn *) SHA256_Init,
88 		(md_update_fn *) SHA256_Update,
89 		(md_final_fn *) SHA256_Final
90 	},
91 	{
92 		SSH_DIGEST_SHA384,
93 		"SHA384",
94 		SHA384_BLOCK_LENGTH,
95 		SHA384_DIGEST_LENGTH,
96 		sizeof(SHA384_CTX),
97 		(md_init_fn *) SHA384_Init,
98 		(md_update_fn *) SHA384_Update,
99 		(md_final_fn *) SHA384_Final
100 	},
101 	{
102 		SSH_DIGEST_SHA512,
103 		"SHA512",
104 		SHA512_BLOCK_LENGTH,
105 		SHA512_DIGEST_LENGTH,
106 		sizeof(SHA512_CTX),
107 		(md_init_fn *) SHA512_Init,
108 		(md_update_fn *) SHA512_Update,
109 		(md_final_fn *) SHA512_Final
110 	}
111 };
112 
113 static const struct ssh_digest *
114 ssh_digest_by_alg(int alg)
115 {
116 	if (alg < 0 || alg >= SSH_DIGEST_MAX)
117 		return NULL;
118 	if (digests[alg].id != alg) /* sanity */
119 		return NULL;
120 	return &(digests[alg]);
121 }
122 
123 int
124 ssh_digest_alg_by_name(const char *name)
125 {
126 	int alg;
127 
128 	for (alg = 0; alg < SSH_DIGEST_MAX; alg++) {
129 		if (strcasecmp(name, digests[alg].name) == 0)
130 			return digests[alg].id;
131 	}
132 	return -1;
133 }
134 
135 const char *
136 ssh_digest_alg_name(int alg)
137 {
138 	const struct ssh_digest *digest = ssh_digest_by_alg(alg);
139 
140 	return digest == NULL ? NULL : digest->name;
141 }
142 
143 size_t
144 ssh_digest_bytes(int alg)
145 {
146 	const struct ssh_digest *digest = ssh_digest_by_alg(alg);
147 
148 	return digest == NULL ? 0 : digest->digest_len;
149 }
150 
151 size_t
152 ssh_digest_blocksize(struct ssh_digest_ctx *ctx)
153 {
154 	const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg);
155 
156 	return digest == NULL ? 0 : digest->block_len;
157 }
158 
159 struct ssh_digest_ctx *
160 ssh_digest_start(int alg)
161 {
162 	const struct ssh_digest *digest = ssh_digest_by_alg(alg);
163 	struct ssh_digest_ctx *ret;
164 
165 	if (digest == NULL || (ret = calloc(1, sizeof(*ret))) == NULL)
166 		return NULL;
167 	if ((ret->mdctx = calloc(1, digest->ctx_len)) == NULL) {
168 		free(ret);
169 		return NULL;
170 	}
171 	ret->alg = alg;
172 	digest->md_init(ret->mdctx);
173 	return ret;
174 }
175 
176 int
177 ssh_digest_copy_state(struct ssh_digest_ctx *from, struct ssh_digest_ctx *to)
178 {
179 	const struct ssh_digest *digest = ssh_digest_by_alg(from->alg);
180 
181 	if (digest == NULL || from->alg != to->alg)
182 		return SSH_ERR_INVALID_ARGUMENT;
183 	memcpy(to->mdctx, from->mdctx, digest->ctx_len);
184 	return 0;
185 }
186 
187 int
188 ssh_digest_update(struct ssh_digest_ctx *ctx, const void *m, size_t mlen)
189 {
190 	const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg);
191 
192 	if (digest == NULL)
193 		return SSH_ERR_INVALID_ARGUMENT;
194 	digest->md_update(ctx->mdctx, m, mlen);
195 	return 0;
196 }
197 
198 int
199 ssh_digest_update_buffer(struct ssh_digest_ctx *ctx, const struct sshbuf *b)
200 {
201 	return ssh_digest_update(ctx, sshbuf_ptr(b), sshbuf_len(b));
202 }
203 
204 int
205 ssh_digest_final(struct ssh_digest_ctx *ctx, u_char *d, size_t dlen)
206 {
207 	const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg);
208 
209 	if (digest == NULL)
210 		return SSH_ERR_INVALID_ARGUMENT;
211 	if (dlen > UINT_MAX)
212 		return SSH_ERR_INVALID_ARGUMENT;
213 	if (dlen < digest->digest_len) /* No truncation allowed */
214 		return SSH_ERR_INVALID_ARGUMENT;
215 	digest->md_final(d, ctx->mdctx);
216 	return 0;
217 }
218 
219 void
220 ssh_digest_free(struct ssh_digest_ctx *ctx)
221 {
222 	const struct ssh_digest *digest;
223 
224 	if (ctx != NULL) {
225 		digest = ssh_digest_by_alg(ctx->alg);
226 		if (digest) {
227 			explicit_bzero(ctx->mdctx, digest->ctx_len);
228 			free(ctx->mdctx);
229 			explicit_bzero(ctx, sizeof(*ctx));
230 			free(ctx);
231 		}
232 	}
233 }
234 
235 int
236 ssh_digest_memory(int alg, const void *m, size_t mlen, u_char *d, size_t dlen)
237 {
238 	struct ssh_digest_ctx *ctx = ssh_digest_start(alg);
239 
240 	if (ctx == NULL)
241 		return SSH_ERR_INVALID_ARGUMENT;
242 	if (ssh_digest_update(ctx, m, mlen) != 0 ||
243 	    ssh_digest_final(ctx, d, dlen) != 0)
244 		return SSH_ERR_INVALID_ARGUMENT;
245 	ssh_digest_free(ctx);
246 	return 0;
247 }
248 
249 int
250 ssh_digest_buffer(int alg, const struct sshbuf *b, u_char *d, size_t dlen)
251 {
252 	return ssh_digest_memory(alg, sshbuf_ptr(b), sshbuf_len(b), d, dlen);
253 }
254 #endif /* !WITH_OPENSSL */
255