Repository navigation
Expand file tree
/
Copy pathmac.c
More file actions
553 lines (474 loc) · 14.3 KB
/
Copy pathmac.c
File metadata and controls
553 lines (474 loc) · 14.3 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
/* Copyright (C) Sara Golemon <sarag@libssh2.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms,
* with or without modification, are permitted provided
* that the following conditions are met:
*
* Redistributions of source code must retain the above
* copyright notice, this list of conditions and the
* following disclaimer.
*
* Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* Neither the name of the copyright holder nor the names
* of any other contributors may be used to endorse or
* promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
* USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include "libssh2_priv.h"
#include "mac.h"
#if defined(LIBSSH2DEBUG) && defined(LIBSSH2_MAC_NONE_INSECURE)
/* mac_none_MAC
*
* Minimalist MAC: No MAC. DO NOT USE.
*
* The SSH2 Transport allows implementations to forego a message
* authentication code. While this is less of a security risk than using
* a "none" cipher, it is still not recommended as disabling MAC hashes
* removes a layer of security.
*
* Enabling this option will allow for "none" as a negotiable method,
* however it still requires that the method be advertised by the remote
* end and that no more-preferable methods are available.
*
*/
static int
mac_none_MAC(LIBSSH2_SESSION * session, unsigned char *buf,
uint32_t seqno, const unsigned char *packet,
size_t packet_len, const unsigned char *addtl,
size_t addtl_len, void **abstract)
{
return 0;
}
static LIBSSH2_MAC_METHOD mac_method_none = {
"none",
0,
0,
NULL,
mac_none_MAC,
NULL,
0
};
#endif /* defined(LIBSSH2DEBUG) && defined(LIBSSH2_MAC_NONE_INSECURE) */
/* mac_method_common_init
* Initialize simple mac methods
*/
static int
mac_method_common_init(LIBSSH2_SESSION * session, unsigned char *key,
int *free_key, void **abstract)
{
*abstract = key;
*free_key = 0;
(void)session;
return 0;
}
/* mac_method_common_dtor
* Cleanup simple mac methods
*/
static int
mac_method_common_dtor(LIBSSH2_SESSION * session, void **abstract)
{
if(*abstract) {
LIBSSH2_FREE(session, *abstract);
}
*abstract = NULL;
return 0;
}
#if LIBSSH2_HMAC_SHA512
/* mac_method_hmac_sha512_hash
* Calculate hash using full sha512 value
*/
static int
mac_method_hmac_sha2_512_hash(LIBSSH2_SESSION * session,
unsigned char *buf, uint32_t seqno,
const unsigned char *packet,
size_t packet_len,
const unsigned char *addtl,
size_t addtl_len, void **abstract)
{
libssh2_hmac_ctx ctx;
unsigned char seqno_buf[4];
int res;
(void)session;
_libssh2_htonu32(seqno_buf, seqno);
if(!_libssh2_hmac_ctx_init(&ctx))
return 1;
res = _libssh2_hmac_sha512_init(&ctx, *abstract, 64) &&
_libssh2_hmac_update(&ctx, seqno_buf, 4) &&
_libssh2_hmac_update(&ctx, packet, packet_len);
if(res && addtl && addtl_len)
res = _libssh2_hmac_update(&ctx, addtl, addtl_len);
if(res)
res = _libssh2_hmac_final(&ctx, buf);
_libssh2_hmac_cleanup(&ctx);
return !res;
}
static const LIBSSH2_MAC_METHOD mac_method_hmac_sha2_512 = {
"hmac-sha2-512",
64,
64,
mac_method_common_init,
mac_method_hmac_sha2_512_hash,
mac_method_common_dtor,
0
};
static const LIBSSH2_MAC_METHOD mac_method_hmac_sha2_512_etm = {
"hmac-sha2-512-etm@openssh.com",
64,
64,
mac_method_common_init,
mac_method_hmac_sha2_512_hash,
mac_method_common_dtor,
1
};
#endif
#if LIBSSH2_HMAC_SHA256
/* mac_method_hmac_sha256_hash
* Calculate hash using full sha256 value
*/
static int
mac_method_hmac_sha2_256_hash(LIBSSH2_SESSION * session,
unsigned char *buf, uint32_t seqno,
const unsigned char *packet,
size_t packet_len,
const unsigned char *addtl,
size_t addtl_len, void **abstract)
{
libssh2_hmac_ctx ctx;
unsigned char seqno_buf[4];
int res;
(void)session;
_libssh2_htonu32(seqno_buf, seqno);
if(!_libssh2_hmac_ctx_init(&ctx))
return 1;
res = _libssh2_hmac_sha256_init(&ctx, *abstract, 32) &&
_libssh2_hmac_update(&ctx, seqno_buf, 4) &&
_libssh2_hmac_update(&ctx, packet, packet_len);
if(res && addtl && addtl_len)
res = _libssh2_hmac_update(&ctx, addtl, addtl_len);
if(res)
res = _libssh2_hmac_final(&ctx, buf);
_libssh2_hmac_cleanup(&ctx);
return !res;
}
static const LIBSSH2_MAC_METHOD mac_method_hmac_sha2_256 = {
"hmac-sha2-256",
32,
32,
mac_method_common_init,
mac_method_hmac_sha2_256_hash,
mac_method_common_dtor,
0
};
static const LIBSSH2_MAC_METHOD mac_method_hmac_sha2_256_etm = {
"hmac-sha2-256-etm@openssh.com",
32,
32,
mac_method_common_init,
mac_method_hmac_sha2_256_hash,
mac_method_common_dtor,
1
};
#endif
/* mac_method_hmac_sha1_hash
* Calculate hash using full sha1 value
*/
static int
mac_method_hmac_sha1_hash(LIBSSH2_SESSION * session,
unsigned char *buf, uint32_t seqno,
const unsigned char *packet,
size_t packet_len,
const unsigned char *addtl,
size_t addtl_len, void **abstract)
{
libssh2_hmac_ctx ctx;
unsigned char seqno_buf[4];
int res;
(void)session;
_libssh2_htonu32(seqno_buf, seqno);
if(!_libssh2_hmac_ctx_init(&ctx))
return 1;
res = _libssh2_hmac_sha1_init(&ctx, *abstract, 20) &&
_libssh2_hmac_update(&ctx, seqno_buf, 4) &&
_libssh2_hmac_update(&ctx, packet, packet_len);
if(res && addtl && addtl_len)
res = _libssh2_hmac_update(&ctx, addtl, addtl_len);
if(res)
res = _libssh2_hmac_final(&ctx, buf);
_libssh2_hmac_cleanup(&ctx);
return !res;
}
static const LIBSSH2_MAC_METHOD mac_method_hmac_sha1 = {
"hmac-sha1",
20,
20,
mac_method_common_init,
mac_method_hmac_sha1_hash,
mac_method_common_dtor,
0
};
static const LIBSSH2_MAC_METHOD mac_method_hmac_sha1_etm = {
"hmac-sha1-etm@openssh.com",
20,
20,
mac_method_common_init,
mac_method_hmac_sha1_hash,
mac_method_common_dtor,
1
};
/* mac_method_hmac_sha1_96_hash
* Calculate hash using first 96 bits of sha1 value
*/
static int
mac_method_hmac_sha1_96_hash(LIBSSH2_SESSION * session,
unsigned char *buf, uint32_t seqno,
const unsigned char *packet,
size_t packet_len,
const unsigned char *addtl,
size_t addtl_len, void **abstract)
{
unsigned char temp[SHA_DIGEST_LENGTH];
if(mac_method_hmac_sha1_hash(session, temp, seqno, packet, packet_len,
addtl, addtl_len, abstract))
return 1;
memcpy(buf, (char *) temp, 96 / 8);
return 0;
}
static const LIBSSH2_MAC_METHOD mac_method_hmac_sha1_96 = {
"hmac-sha1-96",
12,
20,
mac_method_common_init,
mac_method_hmac_sha1_96_hash,
mac_method_common_dtor,
0
};
#if LIBSSH2_MD5
/* mac_method_hmac_md5_hash
* Calculate hash using full md5 value
*/
static int
mac_method_hmac_md5_hash(LIBSSH2_SESSION * session, unsigned char *buf,
uint32_t seqno,
const unsigned char *packet,
size_t packet_len,
const unsigned char *addtl,
size_t addtl_len, void **abstract)
{
libssh2_hmac_ctx ctx;
unsigned char seqno_buf[4];
int res;
(void)session;
_libssh2_htonu32(seqno_buf, seqno);
if(!_libssh2_hmac_ctx_init(&ctx))
return 1;
res = _libssh2_hmac_md5_init(&ctx, *abstract, 16) &&
_libssh2_hmac_update(&ctx, seqno_buf, 4) &&
_libssh2_hmac_update(&ctx, packet, packet_len);
if(res && addtl && addtl_len)
res = _libssh2_hmac_update(&ctx, addtl, addtl_len);
if(res)
res = _libssh2_hmac_final(&ctx, buf);
_libssh2_hmac_cleanup(&ctx);
return !res;
}
static const LIBSSH2_MAC_METHOD mac_method_hmac_md5 = {
"hmac-md5",
16,
16,
mac_method_common_init,
mac_method_hmac_md5_hash,
mac_method_common_dtor,
0
};
/* mac_method_hmac_md5_96_hash
* Calculate hash using first 96 bits of md5 value
*/
static int
mac_method_hmac_md5_96_hash(LIBSSH2_SESSION * session,
unsigned char *buf, uint32_t seqno,
const unsigned char *packet,
size_t packet_len,
const unsigned char *addtl,
size_t addtl_len, void **abstract)
{
unsigned char temp[MD5_DIGEST_LENGTH];
if(mac_method_hmac_md5_hash(session, temp, seqno, packet, packet_len,
addtl, addtl_len, abstract))
return 1;
memcpy(buf, (char *) temp, 96 / 8);
return 0;
}
static const LIBSSH2_MAC_METHOD mac_method_hmac_md5_96 = {
"hmac-md5-96",
12,
16,
mac_method_common_init,
mac_method_hmac_md5_96_hash,
mac_method_common_dtor,
0
};
#endif /* LIBSSH2_MD5 */
#if LIBSSH2_HMAC_RIPEMD
/* mac_method_hmac_ripemd160_hash
* Calculate hash using ripemd160 value
*/
static int
mac_method_hmac_ripemd160_hash(LIBSSH2_SESSION * session,
unsigned char *buf, uint32_t seqno,
const unsigned char *packet,
size_t packet_len,
const unsigned char *addtl,
size_t addtl_len,
void **abstract)
{
libssh2_hmac_ctx ctx;
unsigned char seqno_buf[4];
int res;
(void)session;
_libssh2_htonu32(seqno_buf, seqno);
if(!_libssh2_hmac_ctx_init(&ctx))
return 1;
res = _libssh2_hmac_ripemd160_init(&ctx, *abstract, 20) &&
_libssh2_hmac_update(&ctx, seqno_buf, 4) &&
_libssh2_hmac_update(&ctx, packet, packet_len);
if(res && addtl && addtl_len)
res = _libssh2_hmac_update(&ctx, addtl, addtl_len);
if(res)
res = _libssh2_hmac_final(&ctx, buf);
_libssh2_hmac_cleanup(&ctx);
return !res;
}
static const LIBSSH2_MAC_METHOD mac_method_hmac_ripemd160 = {
"hmac-ripemd160",
20,
20,
mac_method_common_init,
mac_method_hmac_ripemd160_hash,
mac_method_common_dtor,
0
};
static const LIBSSH2_MAC_METHOD mac_method_hmac_ripemd160_openssh_com = {
"hmac-ripemd160@openssh.com",
20,
20,
mac_method_common_init,
mac_method_hmac_ripemd160_hash,
mac_method_common_dtor,
0
};
#endif /* LIBSSH2_HMAC_RIPEMD */
static const LIBSSH2_MAC_METHOD *mac_methods[] = {
#if LIBSSH2_HMAC_SHA256
&mac_method_hmac_sha2_256,
&mac_method_hmac_sha2_256_etm,
#endif
#if LIBSSH2_HMAC_SHA512
&mac_method_hmac_sha2_512,
&mac_method_hmac_sha2_512_etm,
#endif
&mac_method_hmac_sha1,
&mac_method_hmac_sha1_etm,
&mac_method_hmac_sha1_96,
#if LIBSSH2_MD5
&mac_method_hmac_md5,
&mac_method_hmac_md5_96,
#endif
#if LIBSSH2_HMAC_RIPEMD
&mac_method_hmac_ripemd160,
&mac_method_hmac_ripemd160_openssh_com,
#endif /* LIBSSH2_HMAC_RIPEMD */
#if defined(LIBSSH2DEBUG) && defined(LIBSSH2_MAC_NONE_INSECURE)
&mac_method_none,
#endif
NULL
};
const LIBSSH2_MAC_METHOD **
_libssh2_mac_methods(void)
{
return mac_methods;
}
#if LIBSSH2_AES_GCM
static int
mac_method_none_init(LIBSSH2_SESSION * session, unsigned char *key,
int *free_key, void **abstract)
{
(void)session;
(void)key;
(void)free_key;
(void)abstract;
return 0;
}
static int
mac_method_hmac_none_hash(LIBSSH2_SESSION * session,
unsigned char *buf, uint32_t seqno,
const unsigned char *packet,
size_t packet_len,
const unsigned char *addtl,
size_t addtl_len, void **abstract)
{
(void)session;
(void)buf;
(void)seqno;
(void)packet;
(void)packet_len;
(void)addtl;
(void)addtl_len;
(void)abstract;
return 0;
}
static int
mac_method_none_dtor(LIBSSH2_SESSION * session, void **abstract)
{
(void)session;
(void)abstract;
return 0;
}
/* Stub for aes256-gcm@openssh.com crypto type, which has an integrated
HMAC method. This must not be added to mac_methods[] since it cannot be
negotiated separately. */
static const LIBSSH2_MAC_METHOD mac_method_hmac_aesgcm = {
"INTEGRATED-AES-GCM", /* made up name for display only */
16,
16,
mac_method_none_init,
mac_method_hmac_none_hash,
mac_method_none_dtor,
0
};
#endif /* LIBSSH2_AES_GCM */
/* See if the negotiated crypto method has its own authentication scheme that
* obviates the need for a separate negotiated hmac method */
const LIBSSH2_MAC_METHOD *
_libssh2_mac_override(const LIBSSH2_CRYPT_METHOD *crypt)
{
#if LIBSSH2_AES_GCM
if(!strcmp(crypt->name, "aes256-gcm@openssh.com") ||
!strcmp(crypt->name, "aes128-gcm@openssh.com"))
return &mac_method_hmac_aesgcm;
#else
(void) crypt;
#endif /* LIBSSH2_AES_GCM */
return NULL;
}