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