1 /* $OpenBSD: digest-libc.c,v 1.7 2020/02/26 13:40:09 jsg 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 #endif
32 #ifdef HAVE_SHA1_H
33 #include <sha1.h>
34 #endif
35 #ifdef HAVE_SHA2_H
36 #include <sha2.h>
37 #endif
38
39 #include "ssherr.h"
40 #include "sshbuf.h"
41 #include "digest.h"
42
43 typedef void md_init_fn(void *mdctx);
44 typedef void md_update_fn(void *mdctx, const u_int8_t *m, size_t mlen);
45 typedef void md_final_fn(u_int8_t[], void *mdctx);
46
47 struct ssh_digest_ctx {
48 int alg;
49 void *mdctx;
50 };
51
52 struct ssh_digest {
53 int id;
54 const char *name;
55 size_t block_len;
56 size_t digest_len;
57 size_t ctx_len;
58 md_init_fn *md_init;
59 md_update_fn *md_update;
60 md_final_fn *md_final;
61 };
62
63 /* NB. Indexed directly by algorithm number */
64 const struct ssh_digest digests[SSH_DIGEST_MAX] = {
65 {
66 SSH_DIGEST_MD5,
67 "MD5",
68 MD5_BLOCK_LENGTH,
69 MD5_DIGEST_LENGTH,
70 sizeof(MD5_CTX),
71 (md_init_fn *) MD5Init,
72 (md_update_fn *) MD5Update,
73 (md_final_fn *) MD5Final
74 },
75 {
76 SSH_DIGEST_SHA1,
77 "SHA1",
78 SHA1_BLOCK_LENGTH,
79 SHA1_DIGEST_LENGTH,
80 sizeof(SHA1_CTX),
81 (md_init_fn *) SHA1Init,
82 (md_update_fn *) SHA1Update,
83 (md_final_fn *) SHA1Final
84 },
85 {
86 SSH_DIGEST_SHA256,
87 "SHA256",
88 SHA256_BLOCK_LENGTH,
89 SHA256_DIGEST_LENGTH,
90 sizeof(SHA2_CTX),
91 (md_init_fn *) SHA256Init,
92 (md_update_fn *) SHA256Update,
93 (md_final_fn *) SHA256Final
94 },
95 {
96 SSH_DIGEST_SHA384,
97 "SHA384",
98 SHA384_BLOCK_LENGTH,
99 SHA384_DIGEST_LENGTH,
100 sizeof(SHA2_CTX),
101 (md_init_fn *) SHA384Init,
102 (md_update_fn *) SHA384Update,
103 (md_final_fn *) SHA384Final
104 },
105 {
106 SSH_DIGEST_SHA512,
107 "SHA512",
108 SHA512_BLOCK_LENGTH,
109 SHA512_DIGEST_LENGTH,
110 sizeof(SHA2_CTX),
111 (md_init_fn *) SHA512Init,
112 (md_update_fn *) SHA512Update,
113 (md_final_fn *) SHA512Final
114 }
115 };
116
117 static const struct ssh_digest *
ssh_digest_by_alg(int alg)118 ssh_digest_by_alg(int alg)
119 {
120 if (alg < 0 || alg >= SSH_DIGEST_MAX)
121 return NULL;
122 if (digests[alg].id != alg) /* sanity */
123 return NULL;
124 return &(digests[alg]);
125 }
126
127 int
ssh_digest_alg_by_name(const char * name)128 ssh_digest_alg_by_name(const char *name)
129 {
130 int alg;
131
132 for (alg = 0; alg < SSH_DIGEST_MAX; alg++) {
133 if (strcasecmp(name, digests[alg].name) == 0)
134 return digests[alg].id;
135 }
136 return -1;
137 }
138
139 const char *
ssh_digest_alg_name(int alg)140 ssh_digest_alg_name(int alg)
141 {
142 const struct ssh_digest *digest = ssh_digest_by_alg(alg);
143
144 return digest == NULL ? NULL : digest->name;
145 }
146
147 size_t
ssh_digest_bytes(int alg)148 ssh_digest_bytes(int alg)
149 {
150 const struct ssh_digest *digest = ssh_digest_by_alg(alg);
151
152 return digest == NULL ? 0 : digest->digest_len;
153 }
154
155 size_t
ssh_digest_blocksize(struct ssh_digest_ctx * ctx)156 ssh_digest_blocksize(struct ssh_digest_ctx *ctx)
157 {
158 const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg);
159
160 return digest == NULL ? 0 : digest->block_len;
161 }
162
163 struct ssh_digest_ctx *
ssh_digest_start(int alg)164 ssh_digest_start(int alg)
165 {
166 const struct ssh_digest *digest = ssh_digest_by_alg(alg);
167 struct ssh_digest_ctx *ret;
168
169 if (digest == NULL || (ret = calloc(1, sizeof(*ret))) == NULL)
170 return NULL;
171 if ((ret->mdctx = calloc(1, digest->ctx_len)) == NULL) {
172 free(ret);
173 return NULL;
174 }
175 ret->alg = alg;
176 digest->md_init(ret->mdctx);
177 return ret;
178 }
179
180 int
ssh_digest_copy_state(struct ssh_digest_ctx * from,struct ssh_digest_ctx * to)181 ssh_digest_copy_state(struct ssh_digest_ctx *from, struct ssh_digest_ctx *to)
182 {
183 const struct ssh_digest *digest = ssh_digest_by_alg(from->alg);
184
185 if (digest == NULL || from->alg != to->alg)
186 return SSH_ERR_INVALID_ARGUMENT;
187 memcpy(to->mdctx, from->mdctx, digest->ctx_len);
188 return 0;
189 }
190
191 int
ssh_digest_update(struct ssh_digest_ctx * ctx,const void * m,size_t mlen)192 ssh_digest_update(struct ssh_digest_ctx *ctx, const void *m, size_t mlen)
193 {
194 const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg);
195
196 if (digest == NULL)
197 return SSH_ERR_INVALID_ARGUMENT;
198 digest->md_update(ctx->mdctx, m, mlen);
199 return 0;
200 }
201
202 int
ssh_digest_update_buffer(struct ssh_digest_ctx * ctx,const struct sshbuf * b)203 ssh_digest_update_buffer(struct ssh_digest_ctx *ctx, const struct sshbuf *b)
204 {
205 return ssh_digest_update(ctx, sshbuf_ptr(b), sshbuf_len(b));
206 }
207
208 int
ssh_digest_final(struct ssh_digest_ctx * ctx,u_char * d,size_t dlen)209 ssh_digest_final(struct ssh_digest_ctx *ctx, u_char *d, size_t dlen)
210 {
211 const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg);
212
213 if (digest == NULL)
214 return SSH_ERR_INVALID_ARGUMENT;
215 if (dlen > UINT_MAX)
216 return SSH_ERR_INVALID_ARGUMENT;
217 if (dlen < digest->digest_len) /* No truncation allowed */
218 return SSH_ERR_INVALID_ARGUMENT;
219 digest->md_final(d, ctx->mdctx);
220 return 0;
221 }
222
223 void
ssh_digest_free(struct ssh_digest_ctx * ctx)224 ssh_digest_free(struct ssh_digest_ctx *ctx)
225 {
226 const struct ssh_digest *digest;
227
228 if (ctx != NULL) {
229 digest = ssh_digest_by_alg(ctx->alg);
230 if (digest) {
231 explicit_bzero(ctx->mdctx, digest->ctx_len);
232 free(ctx->mdctx);
233 freezero(ctx, sizeof(*ctx));
234 }
235 }
236 }
237
238 int
ssh_digest_memory(int alg,const void * m,size_t mlen,u_char * d,size_t dlen)239 ssh_digest_memory(int alg, const void *m, size_t mlen, u_char *d, size_t dlen)
240 {
241 struct ssh_digest_ctx *ctx = ssh_digest_start(alg);
242
243 if (ctx == NULL)
244 return SSH_ERR_INVALID_ARGUMENT;
245 if (ssh_digest_update(ctx, m, mlen) != 0 ||
246 ssh_digest_final(ctx, d, dlen) != 0)
247 return SSH_ERR_INVALID_ARGUMENT;
248 ssh_digest_free(ctx);
249 return 0;
250 }
251
252 int
ssh_digest_buffer(int alg,const struct sshbuf * b,u_char * d,size_t dlen)253 ssh_digest_buffer(int alg, const struct sshbuf *b, u_char *d, size_t dlen)
254 {
255 return ssh_digest_memory(alg, sshbuf_ptr(b), sshbuf_len(b), d, dlen);
256 }
257 #endif /* !WITH_OPENSSL */
258