xref: /freebsd/crypto/openssh/digest-openssl.c (revision f0cfa1b168014f56c02b83e5f28412cc5f78d117)
1 /* $OpenBSD: digest-openssl.c,v 1.6 2017/03/10 02:59:51 dtucker 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 
44 struct ssh_digest_ctx {
45 	int alg;
46 	EVP_MD_CTX mdctx;
47 };
48 
49 struct 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 */
57 const struct ssh_digest digests[] = {
58 	{ SSH_DIGEST_MD5,	"MD5",	 	16,	EVP_md5 },
59 	{ SSH_DIGEST_RIPEMD160,	"RIPEMD160",	20,	EVP_ripemd160 },
60 	{ SSH_DIGEST_SHA1,	"SHA1",	 	20,	EVP_sha1 },
61 	{ SSH_DIGEST_SHA256,	"SHA256", 	32,	EVP_sha256 },
62 	{ SSH_DIGEST_SHA384,	"SHA384",	48,	EVP_sha384 },
63 	{ SSH_DIGEST_SHA512,	"SHA512", 	64,	EVP_sha512 },
64 	{ -1,			NULL,		0,	NULL },
65 };
66 
67 static const struct ssh_digest *
68 ssh_digest_by_alg(int alg)
69 {
70 	if (alg < 0 || alg >= SSH_DIGEST_MAX)
71 		return NULL;
72 	if (digests[alg].id != alg) /* sanity */
73 		return NULL;
74 	if (digests[alg].mdfunc == NULL)
75 		return NULL;
76 	return &(digests[alg]);
77 }
78 
79 int
80 ssh_digest_alg_by_name(const char *name)
81 {
82 	int alg;
83 
84 	for (alg = 0; digests[alg].id != -1; alg++) {
85 		if (strcasecmp(name, digests[alg].name) == 0)
86 			return digests[alg].id;
87 	}
88 	return -1;
89 }
90 
91 const char *
92 ssh_digest_alg_name(int alg)
93 {
94 	const struct ssh_digest *digest = ssh_digest_by_alg(alg);
95 
96 	return digest == NULL ? NULL : digest->name;
97 }
98 
99 size_t
100 ssh_digest_bytes(int alg)
101 {
102 	const struct ssh_digest *digest = ssh_digest_by_alg(alg);
103 
104 	return digest == NULL ? 0 : digest->digest_len;
105 }
106 
107 size_t
108 ssh_digest_blocksize(struct ssh_digest_ctx *ctx)
109 {
110 	return EVP_MD_CTX_block_size(&ctx->mdctx);
111 }
112 
113 struct ssh_digest_ctx *
114 ssh_digest_start(int alg)
115 {
116 	const struct ssh_digest *digest = ssh_digest_by_alg(alg);
117 	struct ssh_digest_ctx *ret;
118 
119 	if (digest == NULL || ((ret = calloc(1, sizeof(*ret))) == NULL))
120 		return NULL;
121 	ret->alg = alg;
122 	EVP_MD_CTX_init(&ret->mdctx);
123 	if (EVP_DigestInit_ex(&ret->mdctx, digest->mdfunc(), NULL) != 1) {
124 		free(ret);
125 		return NULL;
126 	}
127 	return ret;
128 }
129 
130 int
131 ssh_digest_copy_state(struct ssh_digest_ctx *from, struct ssh_digest_ctx *to)
132 {
133 	if (from->alg != to->alg)
134 		return SSH_ERR_INVALID_ARGUMENT;
135 	/* we have bcopy-style order while openssl has memcpy-style */
136 	if (!EVP_MD_CTX_copy_ex(&to->mdctx, &from->mdctx))
137 		return SSH_ERR_LIBCRYPTO_ERROR;
138 	return 0;
139 }
140 
141 int
142 ssh_digest_update(struct ssh_digest_ctx *ctx, const void *m, size_t mlen)
143 {
144 	if (EVP_DigestUpdate(&ctx->mdctx, m, mlen) != 1)
145 		return SSH_ERR_LIBCRYPTO_ERROR;
146 	return 0;
147 }
148 
149 int
150 ssh_digest_update_buffer(struct ssh_digest_ctx *ctx, const struct sshbuf *b)
151 {
152 	return ssh_digest_update(ctx, sshbuf_ptr(b), sshbuf_len(b));
153 }
154 
155 int
156 ssh_digest_final(struct ssh_digest_ctx *ctx, u_char *d, size_t dlen)
157 {
158 	const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg);
159 	u_int l = dlen;
160 
161 	if (digest == NULL || dlen > UINT_MAX)
162 		return SSH_ERR_INVALID_ARGUMENT;
163 	if (dlen < digest->digest_len) /* No truncation allowed */
164 		return SSH_ERR_INVALID_ARGUMENT;
165 	if (EVP_DigestFinal_ex(&ctx->mdctx, d, &l) != 1)
166 		return SSH_ERR_LIBCRYPTO_ERROR;
167 	if (l != digest->digest_len) /* sanity */
168 		return SSH_ERR_INTERNAL_ERROR;
169 	return 0;
170 }
171 
172 void
173 ssh_digest_free(struct ssh_digest_ctx *ctx)
174 {
175 	if (ctx != NULL) {
176 		EVP_MD_CTX_cleanup(&ctx->mdctx);
177 		explicit_bzero(ctx, sizeof(*ctx));
178 		free(ctx);
179 	}
180 }
181 
182 int
183 ssh_digest_memory(int alg, const void *m, size_t mlen, u_char *d, size_t dlen)
184 {
185 	const struct ssh_digest *digest = ssh_digest_by_alg(alg);
186 	u_int mdlen;
187 
188 	if (digest == NULL)
189 		return SSH_ERR_INVALID_ARGUMENT;
190 	if (dlen > UINT_MAX)
191 		return SSH_ERR_INVALID_ARGUMENT;
192 	if (dlen < digest->digest_len)
193 		return SSH_ERR_INVALID_ARGUMENT;
194 	mdlen = dlen;
195 	if (!EVP_Digest(m, mlen, d, &mdlen, digest->mdfunc(), NULL))
196 		return SSH_ERR_LIBCRYPTO_ERROR;
197 	return 0;
198 }
199 
200 int
201 ssh_digest_buffer(int alg, const struct sshbuf *b, u_char *d, size_t dlen)
202 {
203 	return ssh_digest_memory(alg, sshbuf_ptr(b), sshbuf_len(b), d, dlen);
204 }
205 #endif /* WITH_OPENSSL */
206