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 #if !defined(SHA256_BLOCK_LENGTH) && defined(SHA256_HMAC_BLOCK_SIZE)
40 #define SHA256_BLOCK_LENGTH SHA256_HMAC_BLOCK_SIZE
41 #endif
42 #if !defined(SHA384_BLOCK_LENGTH) && defined(SHA512_HMAC_BLOCK_SIZE)
43 #define SHA384_BLOCK_LENGTH SHA512_HMAC_BLOCK_SIZE
44 #endif
45 #if !defined(SHA512_BLOCK_LENGTH) && defined(SHA512_HMAC_BLOCK_SIZE)
46 #define SHA512_BLOCK_LENGTH SHA512_HMAC_BLOCK_SIZE
47 #endif
48
49 #include "ssherr.h"
50 #include "sshbuf.h"
51 #include "digest.h"
52
53 typedef void md_init_fn(void *mdctx);
54 typedef void md_update_fn(void *mdctx, const u_int8_t *m, size_t mlen);
55 typedef void md_final_fn(u_int8_t[], void *mdctx);
56
57 struct ssh_digest_ctx {
58 int alg;
59 void *mdctx;
60 };
61
62 struct ssh_digest {
63 int id;
64 const char *name;
65 size_t block_len;
66 size_t digest_len;
67 size_t ctx_len;
68 md_init_fn *md_init;
69 md_update_fn *md_update;
70 md_final_fn *md_final;
71 };
72
73 /* NB. Indexed directly by algorithm number */
74 const struct ssh_digest digests[SSH_DIGEST_MAX] = {
75 {
76 SSH_DIGEST_MD5,
77 "MD5",
78 MD5_BLOCK_LENGTH,
79 MD5_DIGEST_LENGTH,
80 sizeof(MD5_CTX),
81 (md_init_fn *) MD5Init,
82 (md_update_fn *) MD5Update,
83 (md_final_fn *) MD5Final
84 },
85 {
86 SSH_DIGEST_SHA1,
87 "SHA1",
88 SHA1_BLOCK_LENGTH,
89 SHA1_DIGEST_LENGTH,
90 sizeof(SHA1_CTX),
91 (md_init_fn *) SHA1Init,
92 (md_update_fn *) SHA1Update,
93 (md_final_fn *) SHA1Final
94 },
95 {
96 SSH_DIGEST_SHA256,
97 "SHA256",
98 SHA256_BLOCK_LENGTH,
99 SHA256_DIGEST_LENGTH,
100 sizeof(SHA2_CTX),
101 (md_init_fn *) SHA256Init,
102 (md_update_fn *) SHA256Update,
103 (md_final_fn *) SHA256Final
104 },
105 {
106 SSH_DIGEST_SHA384,
107 "SHA384",
108 SHA384_BLOCK_LENGTH,
109 SHA384_DIGEST_LENGTH,
110 sizeof(SHA2_CTX),
111 (md_init_fn *) SHA384Init,
112 (md_update_fn *) SHA384Update,
113 (md_final_fn *) SHA384Final
114 },
115 {
116 SSH_DIGEST_SHA512,
117 "SHA512",
118 SHA512_BLOCK_LENGTH,
119 SHA512_DIGEST_LENGTH,
120 sizeof(SHA2_CTX),
121 (md_init_fn *) SHA512Init,
122 (md_update_fn *) SHA512Update,
123 (md_final_fn *) SHA512Final
124 }
125 };
126
127 static const struct ssh_digest *
ssh_digest_by_alg(int alg)128 ssh_digest_by_alg(int alg)
129 {
130 if (alg < 0 || alg >= SSH_DIGEST_MAX)
131 return NULL;
132 if (digests[alg].id != alg) /* sanity */
133 return NULL;
134 return &(digests[alg]);
135 }
136
137 int
ssh_digest_alg_by_name(const char * name)138 ssh_digest_alg_by_name(const char *name)
139 {
140 int alg;
141
142 for (alg = 0; alg < SSH_DIGEST_MAX; alg++) {
143 if (strcasecmp(name, digests[alg].name) == 0)
144 return digests[alg].id;
145 }
146 return -1;
147 }
148
149 const char *
ssh_digest_alg_name(int alg)150 ssh_digest_alg_name(int alg)
151 {
152 const struct ssh_digest *digest = ssh_digest_by_alg(alg);
153
154 return digest == NULL ? NULL : digest->name;
155 }
156
157 size_t
ssh_digest_bytes(int alg)158 ssh_digest_bytes(int alg)
159 {
160 const struct ssh_digest *digest = ssh_digest_by_alg(alg);
161
162 return digest == NULL ? 0 : digest->digest_len;
163 }
164
165 size_t
ssh_digest_blocksize(struct ssh_digest_ctx * ctx)166 ssh_digest_blocksize(struct ssh_digest_ctx *ctx)
167 {
168 const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg);
169
170 return digest == NULL ? 0 : digest->block_len;
171 }
172
173 struct ssh_digest_ctx *
ssh_digest_start(int alg)174 ssh_digest_start(int alg)
175 {
176 const struct ssh_digest *digest = ssh_digest_by_alg(alg);
177 struct ssh_digest_ctx *ret;
178
179 if (digest == NULL || (ret = calloc(1, sizeof(*ret))) == NULL)
180 return NULL;
181 if ((ret->mdctx = calloc(1, digest->ctx_len)) == NULL) {
182 free(ret);
183 return NULL;
184 }
185 ret->alg = alg;
186 digest->md_init(ret->mdctx);
187 return ret;
188 }
189
190 int
ssh_digest_copy_state(struct ssh_digest_ctx * from,struct ssh_digest_ctx * to)191 ssh_digest_copy_state(struct ssh_digest_ctx *from, struct ssh_digest_ctx *to)
192 {
193 const struct ssh_digest *digest = ssh_digest_by_alg(from->alg);
194
195 if (digest == NULL || from->alg != to->alg)
196 return SSH_ERR_INVALID_ARGUMENT;
197 memcpy(to->mdctx, from->mdctx, digest->ctx_len);
198 return 0;
199 }
200
201 int
ssh_digest_update(struct ssh_digest_ctx * ctx,const void * m,size_t mlen)202 ssh_digest_update(struct ssh_digest_ctx *ctx, const void *m, size_t mlen)
203 {
204 const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg);
205
206 if (digest == NULL)
207 return SSH_ERR_INVALID_ARGUMENT;
208 digest->md_update(ctx->mdctx, m, mlen);
209 return 0;
210 }
211
212 int
ssh_digest_update_buffer(struct ssh_digest_ctx * ctx,const struct sshbuf * b)213 ssh_digest_update_buffer(struct ssh_digest_ctx *ctx, const struct sshbuf *b)
214 {
215 return ssh_digest_update(ctx, sshbuf_ptr(b), sshbuf_len(b));
216 }
217
218 int
ssh_digest_final(struct ssh_digest_ctx * ctx,u_char * d,size_t dlen)219 ssh_digest_final(struct ssh_digest_ctx *ctx, u_char *d, size_t dlen)
220 {
221 const struct ssh_digest *digest = ssh_digest_by_alg(ctx->alg);
222
223 if (digest == NULL)
224 return SSH_ERR_INVALID_ARGUMENT;
225 if (dlen > UINT_MAX)
226 return SSH_ERR_INVALID_ARGUMENT;
227 if (dlen < digest->digest_len) /* No truncation allowed */
228 return SSH_ERR_INVALID_ARGUMENT;
229 digest->md_final(d, ctx->mdctx);
230 return 0;
231 }
232
233 void
ssh_digest_free(struct ssh_digest_ctx * ctx)234 ssh_digest_free(struct ssh_digest_ctx *ctx)
235 {
236 const struct ssh_digest *digest;
237
238 if (ctx != NULL) {
239 digest = ssh_digest_by_alg(ctx->alg);
240 if (digest) {
241 explicit_bzero(ctx->mdctx, digest->ctx_len);
242 free(ctx->mdctx);
243 freezero(ctx, sizeof(*ctx));
244 }
245 }
246 }
247
248 int
ssh_digest_memory(int alg,const void * m,size_t mlen,u_char * d,size_t dlen)249 ssh_digest_memory(int alg, const void *m, size_t mlen, u_char *d, size_t dlen)
250 {
251 struct ssh_digest_ctx *ctx = ssh_digest_start(alg);
252
253 if (ctx == NULL)
254 return SSH_ERR_INVALID_ARGUMENT;
255 if (ssh_digest_update(ctx, m, mlen) != 0 ||
256 ssh_digest_final(ctx, d, dlen) != 0)
257 return SSH_ERR_INVALID_ARGUMENT;
258 ssh_digest_free(ctx);
259 return 0;
260 }
261
262 int
ssh_digest_buffer(int alg,const struct sshbuf * b,u_char * d,size_t dlen)263 ssh_digest_buffer(int alg, const struct sshbuf *b, u_char *d, size_t dlen)
264 {
265 return ssh_digest_memory(alg, sshbuf_ptr(b), sshbuf_len(b), d, dlen);
266 }
267 #endif /* !WITH_OPENSSL */
268