digest-libc.c revision 294666 
1/* $OpenBSD: digest-libc.c,v 1.2 2014/02/02 03:44:31 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__RCSID("$FreeBSD: stable/10/crypto/openssh/digest-libc.c 294666 2016-01-24 15:44:57Z des $");
21
22#include <sys/types.h>
23#include <limits.h>
24#include <stdlib.h>
25#include <string.h>
26
27#include <md5.h>
28#include <rmd160.h>
29#include <sha1.h>
30#include <sha2.h>
31
32#include "buffer.h"
33#include "digest.h"
34
35typedef void md_init_fn(void *mdctx);
36typedef void md_update_fn(void *mdctx, const u_int8_t *m, size_t mlen);
37typedef void md_final_fn(u_int8_t[], void *mdctx);
38
39struct ssh_digest_ctx {
40	int alg;
41	void *mdctx;
42};
43
44struct ssh_digest {
45	int id;
46	const char *name;
47	size_t block_len;
48	size_t digest_len;
49	size_t ctx_len;
50	md_init_fn *md_init;
51	md_update_fn *md_update;
52	md_final_fn *md_final;
53};
54
55/* NB. Indexed directly by algorithm number */
56const struct ssh_digest digests[SSH_DIGEST_MAX] = {
57	{
58		SSH_DIGEST_MD5,
59		"MD5",
60		MD5_BLOCK_LENGTH,
61		MD5_DIGEST_LENGTH,
62		sizeof(MD5_CTX),
63		(md_init_fn *) MD5Init,
64		(md_update_fn *) MD5Update,
65		(md_final_fn *) MD5Final
66	},
67	{
68		SSH_DIGEST_RIPEMD160,
69		"RIPEMD160",
70		RMD160_BLOCK_LENGTH,
71		RMD160_DIGEST_LENGTH,
72		sizeof(RMD160_CTX),
73		(md_init_fn *) RMD160Init,
74		(md_update_fn *) RMD160Update,
75		(md_final_fn *) RMD160Final
76	},
77	{
78		SSH_DIGEST_SHA1,
79		"SHA1",
80		SHA1_BLOCK_LENGTH,
81		SHA1_DIGEST_LENGTH,
82		sizeof(SHA1_CTX),
83		(md_init_fn *) SHA1Init,
84		(md_update_fn *) SHA1Update,
85		(md_final_fn *) SHA1Final
86	},
87	{
88		SSH_DIGEST_SHA256,
89		"SHA256",
90		SHA256_BLOCK_LENGTH,
91		SHA256_DIGEST_LENGTH,
92		sizeof(SHA2_CTX),
93		(md_init_fn *) SHA256Init,
94		(md_update_fn *) SHA256Update,
95		(md_final_fn *) SHA256Final
96	},
97	{
98		SSH_DIGEST_SHA384,
99		"SHA384",
100		SHA384_BLOCK_LENGTH,
101		SHA384_DIGEST_LENGTH,
102		sizeof(SHA2_CTX),
103		(md_init_fn *) SHA384Init,
104		(md_update_fn *) SHA384Update,
105		(md_final_fn *) SHA384Final
106	},
107	{
108		SSH_DIGEST_SHA512,
109		"SHA512",
110		SHA512_BLOCK_LENGTH,
111		SHA512_DIGEST_LENGTH,
112		sizeof(SHA2_CTX),
113		(md_init_fn *) SHA512Init,
114		(md_update_fn *) SHA512Update,
115		(md_final_fn *) SHA512Final
116	}
117};
118
119static const struct ssh_digest *
120ssh_digest_by_alg(int alg)
121{
122	if (alg < 0 || alg >= SSH_DIGEST_MAX)
123		return NULL;
124	if (digests[alg].id != alg) /* sanity */
125		return NULL;
126	return &(digests[alg]);
127}
128
129size_t
130ssh_digest_bytes(int alg)
131{
132	const struct ssh_digest *digest = ssh_digest_by_alg(alg);
133
134	return digest == NULL ? 0 : digest->digest_len;
135}
136
137size_t
138ssh_digest_blocksize(struct ssh_digest_ctx *ctx)
139{
140	const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg);
141
142	return digest == NULL ? 0 : digest->block_len;
143}
144
145struct ssh_digest_ctx *
146ssh_digest_start(int alg)
147{
148	const struct ssh_digest *digest = ssh_digest_by_alg(alg);
149	struct ssh_digest_ctx *ret;
150
151	if (digest == NULL || (ret = calloc(1, sizeof(*ret))) == NULL)
152		return NULL;
153	if ((ret->mdctx = calloc(1, digest->ctx_len)) == NULL) {
154		free(ret);
155		return NULL;
156	}
157	ret->alg = alg;
158	digest->md_init(ret->mdctx);
159	return ret;
160}
161
162int
163ssh_digest_copy_state(struct ssh_digest_ctx *from, struct ssh_digest_ctx *to)
164{
165	const struct ssh_digest *digest = ssh_digest_by_alg(from->alg);
166
167	if (digest == NULL || from->alg != to->alg)
168		return -1;
169	memcpy(to->mdctx, from->mdctx, digest->ctx_len);
170	return 0;
171}
172
173int
174ssh_digest_update(struct ssh_digest_ctx *ctx, const void *m, size_t mlen)
175{
176	const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg);
177
178	if (digest == NULL)
179		return -1;
180	digest->md_update(ctx->mdctx, m, mlen);
181	return 0;
182}
183
184int
185ssh_digest_update_buffer(struct ssh_digest_ctx *ctx, const Buffer *b)
186{
187	return ssh_digest_update(ctx, buffer_ptr(b), buffer_len(b));
188}
189
190int
191ssh_digest_final(struct ssh_digest_ctx *ctx, u_char *d, size_t dlen)
192{
193	const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg);
194
195	if (digest == NULL)
196		return -1;
197	if (dlen > UINT_MAX)
198		return -1;
199	if (dlen < digest->digest_len) /* No truncation allowed */
200		return -1;
201	digest->md_final(d, ctx->mdctx);
202	return 0;
203}
204
205void
206ssh_digest_free(struct ssh_digest_ctx *ctx)
207{
208	const struct ssh_digest *digest;
209
210	if (ctx != NULL) {
211		digest = ssh_digest_by_alg(ctx->alg);
212		if (digest) {
213			explicit_bzero(ctx->mdctx, digest->ctx_len);
214			free(ctx->mdctx);
215			explicit_bzero(ctx, sizeof(*ctx));
216			free(ctx);
217		}
218	}
219}
220
221int
222ssh_digest_memory(int alg, const void *m, size_t mlen, u_char *d, size_t dlen)
223{
224	struct ssh_digest_ctx *ctx = ssh_digest_start(alg);
225
226	if (ctx == NULL)
227		return -1;
228	if (ssh_digest_update(ctx, m, mlen) != 0 ||
229	    ssh_digest_final(ctx, d, dlen) != 0)
230		return -1;
231	ssh_digest_free(ctx);
232	return 0;
233}
234
235int
236ssh_digest_buffer(int alg, const Buffer *b, u_char *d, size_t dlen)
237{
238	return ssh_digest_memory(alg, buffer_ptr(b), buffer_len(b), d, dlen);
239}
240