xref: /openssh-portable/digest-openssl.c (revision 482d23bc)
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 
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_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 
66 static const struct ssh_digest *
ssh_digest_by_alg(int alg)67 ssh_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 
78 int
ssh_digest_alg_by_name(const char * name)79 ssh_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 
90 const char *
ssh_digest_alg_name(int alg)91 ssh_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 
98 size_t
ssh_digest_bytes(int alg)99 ssh_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 
106 size_t
ssh_digest_blocksize(struct ssh_digest_ctx * ctx)107 ssh_digest_blocksize(struct ssh_digest_ctx *ctx)
108 {
109 	return EVP_MD_CTX_block_size(ctx->mdctx);
110 }
111 
112 struct ssh_digest_ctx *
ssh_digest_start(int alg)113 ssh_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 
132 int
ssh_digest_copy_state(struct ssh_digest_ctx * from,struct ssh_digest_ctx * to)133 ssh_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 
143 int
ssh_digest_update(struct ssh_digest_ctx * ctx,const void * m,size_t mlen)144 ssh_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 
151 int
ssh_digest_update_buffer(struct ssh_digest_ctx * ctx,const struct sshbuf * b)152 ssh_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 
157 int
ssh_digest_final(struct ssh_digest_ctx * ctx,u_char * d,size_t dlen)158 ssh_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 
174 void
ssh_digest_free(struct ssh_digest_ctx * ctx)175 ssh_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 
183 int
ssh_digest_memory(int alg,const void * m,size_t mlen,u_char * d,size_t dlen)184 ssh_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 
201 int
ssh_digest_buffer(int alg,const struct sshbuf * b,u_char * d,size_t dlen)202 ssh_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