1/* $OpenBSD: digest-openssl.c,v 1.7 2017/05/08 22:57:38 djm Exp $ */
2/*
3 * Copyright (c) 2013 Damien Miller <djm@mindrot.org>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18#include "includes.h"
19
20#ifdef WITH_OPENSSL
21
22#include <sys/types.h>
23#include <limits.h>
24#include <stdlib.h>
25#include <string.h>
26
27#include <openssl/evp.h>
28
29#include "openbsd-compat/openssl-compat.h"
30
31#include "sshbuf.h"
32#include "digest.h"
33#include "ssherr.h"
34
35#ifndef HAVE_EVP_RIPEMD160
36# define EVP_ripemd160 NULL
37#endif /* HAVE_EVP_RIPEMD160 */
38#ifndef HAVE_EVP_SHA256
39# define EVP_sha256 NULL
40# define EVP_sha384 NULL
41# define EVP_sha512 NULL
42#endif /* HAVE_EVP_SHA256 */
43
44struct ssh_digest_ctx {
45	int alg;
46	EVP_MD_CTX *mdctx;
47};
48
49struct ssh_digest {
50	int id;
51	const char *name;
52	size_t digest_len;
53	const EVP_MD *(*mdfunc)(void);
54};
55
56/* NB. Indexed directly by algorithm number */
57const struct ssh_digest digests[] = {
58	{ SSH_DIGEST_MD5,	"MD5",	 	16,	EVP_md5 },
59	{ SSH_DIGEST_SHA1,	"SHA1",	 	20,	EVP_sha1 },
60	{ SSH_DIGEST_SHA256,	"SHA256", 	32,	EVP_sha256 },
61	{ SSH_DIGEST_SHA384,	"SHA384",	48,	EVP_sha384 },
62	{ SSH_DIGEST_SHA512,	"SHA512", 	64,	EVP_sha512 },
63	{ -1,			NULL,		0,	NULL },
64};
65
66static const struct ssh_digest *
67ssh_digest_by_alg(int alg)
68{
69	if (alg < 0 || alg >= SSH_DIGEST_MAX)
70		return NULL;
71	if (digests[alg].id != alg) /* sanity */
72		return NULL;
73	if (digests[alg].mdfunc == NULL)
74		return NULL;
75	return &(digests[alg]);
76}
77
78int
79ssh_digest_alg_by_name(const char *name)
80{
81	int alg;
82
83	for (alg = 0; digests[alg].id != -1; alg++) {
84		if (strcasecmp(name, digests[alg].name) == 0)
85			return digests[alg].id;
86	}
87	return -1;
88}
89
90const char *
91ssh_digest_alg_name(int alg)
92{
93	const struct ssh_digest *digest = ssh_digest_by_alg(alg);
94
95	return digest == NULL ? NULL : digest->name;
96}
97
98size_t
99ssh_digest_bytes(int alg)
100{
101	const struct ssh_digest *digest = ssh_digest_by_alg(alg);
102
103	return digest == NULL ? 0 : digest->digest_len;
104}
105
106size_t
107ssh_digest_blocksize(struct ssh_digest_ctx *ctx)
108{
109	return EVP_MD_CTX_block_size(ctx->mdctx);
110}
111
112struct ssh_digest_ctx *
113ssh_digest_start(int alg)
114{
115	const struct ssh_digest *digest = ssh_digest_by_alg(alg);
116	struct ssh_digest_ctx *ret;
117
118	if (digest == NULL || ((ret = calloc(1, sizeof(*ret))) == NULL))
119		return NULL;
120	ret->alg = alg;
121	if ((ret->mdctx = EVP_MD_CTX_new()) == NULL) {
122		free(ret);
123		return NULL;
124	}
125	if (EVP_DigestInit_ex(ret->mdctx, digest->mdfunc(), NULL) != 1) {
126		ssh_digest_free(ret);
127		return NULL;
128	}
129	return ret;
130}
131
132int
133ssh_digest_copy_state(struct ssh_digest_ctx *from, struct ssh_digest_ctx *to)
134{
135	if (from->alg != to->alg)
136		return SSH_ERR_INVALID_ARGUMENT;
137	/* we have bcopy-style order while openssl has memcpy-style */
138	if (!EVP_MD_CTX_copy_ex(to->mdctx, from->mdctx))
139		return SSH_ERR_LIBCRYPTO_ERROR;
140	return 0;
141}
142
143int
144ssh_digest_update(struct ssh_digest_ctx *ctx, const void *m, size_t mlen)
145{
146	if (EVP_DigestUpdate(ctx->mdctx, m, mlen) != 1)
147		return SSH_ERR_LIBCRYPTO_ERROR;
148	return 0;
149}
150
151int
152ssh_digest_update_buffer(struct ssh_digest_ctx *ctx, const struct sshbuf *b)
153{
154	return ssh_digest_update(ctx, sshbuf_ptr(b), sshbuf_len(b));
155}
156
157int
158ssh_digest_final(struct ssh_digest_ctx *ctx, u_char *d, size_t dlen)
159{
160	const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg);
161	u_int l = dlen;
162
163	if (digest == NULL || dlen > UINT_MAX)
164		return SSH_ERR_INVALID_ARGUMENT;
165	if (dlen < digest->digest_len) /* No truncation allowed */
166		return SSH_ERR_INVALID_ARGUMENT;
167	if (EVP_DigestFinal_ex(ctx->mdctx, d, &l) != 1)
168		return SSH_ERR_LIBCRYPTO_ERROR;
169	if (l != digest->digest_len) /* sanity */
170		return SSH_ERR_INTERNAL_ERROR;
171	return 0;
172}
173
174void
175ssh_digest_free(struct ssh_digest_ctx *ctx)
176{
177	if (ctx == NULL)
178		return;
179	EVP_MD_CTX_free(ctx->mdctx);
180	freezero(ctx, sizeof(*ctx));
181}
182
183int
184ssh_digest_memory(int alg, const void *m, size_t mlen, u_char *d, size_t dlen)
185{
186	const struct ssh_digest *digest = ssh_digest_by_alg(alg);
187	u_int mdlen;
188
189	if (digest == NULL)
190		return SSH_ERR_INVALID_ARGUMENT;
191	if (dlen > UINT_MAX)
192		return SSH_ERR_INVALID_ARGUMENT;
193	if (dlen < digest->digest_len)
194		return SSH_ERR_INVALID_ARGUMENT;
195	mdlen = dlen;
196	if (!EVP_Digest(m, mlen, d, &mdlen, digest->mdfunc(), NULL))
197		return SSH_ERR_LIBCRYPTO_ERROR;
198	return 0;
199}
200
201int
202ssh_digest_buffer(int alg, const struct sshbuf *b, u_char *d, size_t dlen)
203{
204	return ssh_digest_memory(alg, sshbuf_ptr(b), sshbuf_len(b), d, dlen);
205}
206#endif /* WITH_OPENSSL */
207