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
39typedef void md_init_fn(void *mdctx);
40typedef void md_update_fn(void *mdctx, const u_int8_t *m, size_t mlen);
41typedef void md_final_fn(u_int8_t[], void *mdctx);
42
43struct ssh_digest_ctx {
44	int alg;
45	void *mdctx;
46};
47
48struct 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 */
60const 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
113static const struct ssh_digest *
114ssh_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
123int
124ssh_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
135const char *
136ssh_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
143size_t
144ssh_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
151size_t
152ssh_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
159struct ssh_digest_ctx *
160ssh_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
176int
177ssh_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
187int
188ssh_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
198int
199ssh_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
204int
205ssh_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
219void
220ssh_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
235int
236ssh_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
249int
250ssh_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