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Vlad Yasevich60c778b2008-01-11 09:57:09 -05001/* SCTP kernel implementation
Vlad Yasevich1f485642007-10-09 01:15:59 -07002 * (C) Copyright 2007 Hewlett-Packard Development Company, L.P.
3 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -05004 * This file is part of the SCTP kernel implementation
Vlad Yasevich1f485642007-10-09 01:15:59 -07005 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -05006 * This SCTP implementation is free software;
Vlad Yasevich1f485642007-10-09 01:15:59 -07007 * you can redistribute it and/or modify it under the terms of
8 * the GNU General Public License as published by
9 * the Free Software Foundation; either version 2, or (at your option)
10 * any later version.
11 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -050012 * This SCTP implementation is distributed in the hope that it
Vlad Yasevich1f485642007-10-09 01:15:59 -070013 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
14 * ************************
15 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
16 * See the GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
Jeff Kirsher4b2f13a2013-12-06 06:28:48 -080019 * along with GNU CC; see the file COPYING. If not, see
20 * <http://www.gnu.org/licenses/>.
Vlad Yasevich1f485642007-10-09 01:15:59 -070021 *
22 * Please send any bug reports or fixes you make to the
23 * email address(es):
Daniel Borkmann91705c62013-07-23 14:51:47 +020024 * lksctp developers <linux-sctp@vger.kernel.org>
Vlad Yasevich1f485642007-10-09 01:15:59 -070025 *
Vlad Yasevich1f485642007-10-09 01:15:59 -070026 * Written or modified by:
27 * Vlad Yasevich <vladislav.yasevich@hp.com>
Vlad Yasevich1f485642007-10-09 01:15:59 -070028 */
29
Herbert Xu5821c762016-01-24 21:20:12 +080030#include <crypto/hash.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090031#include <linux/slab.h>
Vlad Yasevich1f485642007-10-09 01:15:59 -070032#include <linux/types.h>
Vlad Yasevich1f485642007-10-09 01:15:59 -070033#include <linux/scatterlist.h>
34#include <net/sctp/sctp.h>
35#include <net/sctp/auth.h>
36
37static struct sctp_hmac sctp_hmac_list[SCTP_AUTH_NUM_HMACS] = {
38 {
39 /* id 0 is reserved. as all 0 */
40 .hmac_id = SCTP_AUTH_HMAC_ID_RESERVED_0,
41 },
42 {
43 .hmac_id = SCTP_AUTH_HMAC_ID_SHA1,
wangweidongcb3f8372013-12-23 12:16:50 +080044 .hmac_name = "hmac(sha1)",
Vlad Yasevich1f485642007-10-09 01:15:59 -070045 .hmac_len = SCTP_SHA1_SIG_SIZE,
46 },
47 {
48 /* id 2 is reserved as well */
49 .hmac_id = SCTP_AUTH_HMAC_ID_RESERVED_2,
50 },
Vlad Yasevichb7e0fe92007-11-29 09:53:52 -050051#if defined (CONFIG_CRYPTO_SHA256) || defined (CONFIG_CRYPTO_SHA256_MODULE)
Vlad Yasevich1f485642007-10-09 01:15:59 -070052 {
53 .hmac_id = SCTP_AUTH_HMAC_ID_SHA256,
wangweidongcb3f8372013-12-23 12:16:50 +080054 .hmac_name = "hmac(sha256)",
Vlad Yasevich1f485642007-10-09 01:15:59 -070055 .hmac_len = SCTP_SHA256_SIG_SIZE,
56 }
Vlad Yasevichb7e0fe92007-11-29 09:53:52 -050057#endif
Vlad Yasevich1f485642007-10-09 01:15:59 -070058};
59
60
61void sctp_auth_key_put(struct sctp_auth_bytes *key)
62{
63 if (!key)
64 return;
65
66 if (atomic_dec_and_test(&key->refcnt)) {
Daniel Borkmann586c31f2013-02-07 00:55:37 +000067 kzfree(key);
Vlad Yasevich1f485642007-10-09 01:15:59 -070068 SCTP_DBG_OBJCNT_DEC(keys);
69 }
70}
71
72/* Create a new key structure of a given length */
73static struct sctp_auth_bytes *sctp_auth_create_key(__u32 key_len, gfp_t gfp)
74{
75 struct sctp_auth_bytes *key;
76
Vlad Yasevich30c22352008-08-25 15:16:19 -070077 /* Verify that we are not going to overflow INT_MAX */
Xi Wangc89304b2011-11-29 09:26:30 +000078 if (key_len > (INT_MAX - sizeof(struct sctp_auth_bytes)))
Vlad Yasevich30c22352008-08-25 15:16:19 -070079 return NULL;
80
Vlad Yasevich1f485642007-10-09 01:15:59 -070081 /* Allocate the shared key */
82 key = kmalloc(sizeof(struct sctp_auth_bytes) + key_len, gfp);
83 if (!key)
84 return NULL;
85
86 key->len = key_len;
87 atomic_set(&key->refcnt, 1);
88 SCTP_DBG_OBJCNT_INC(keys);
89
90 return key;
91}
92
93/* Create a new shared key container with a give key id */
94struct sctp_shared_key *sctp_auth_shkey_create(__u16 key_id, gfp_t gfp)
95{
96 struct sctp_shared_key *new;
97
98 /* Allocate the shared key container */
99 new = kzalloc(sizeof(struct sctp_shared_key), gfp);
100 if (!new)
101 return NULL;
102
103 INIT_LIST_HEAD(&new->key_list);
104 new->key_id = key_id;
105
106 return new;
107}
108
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300109/* Free the shared key structure */
Adrian Bunk8ad7c62b2007-10-26 04:21:23 -0700110static void sctp_auth_shkey_free(struct sctp_shared_key *sh_key)
Vlad Yasevich1f485642007-10-09 01:15:59 -0700111{
112 BUG_ON(!list_empty(&sh_key->key_list));
113 sctp_auth_key_put(sh_key->key);
114 sh_key->key = NULL;
115 kfree(sh_key);
116}
117
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300118/* Destroy the entire key list. This is done during the
Vlad Yasevich1f485642007-10-09 01:15:59 -0700119 * associon and endpoint free process.
120 */
121void sctp_auth_destroy_keys(struct list_head *keys)
122{
123 struct sctp_shared_key *ep_key;
124 struct sctp_shared_key *tmp;
125
126 if (list_empty(keys))
127 return;
128
129 key_for_each_safe(ep_key, tmp, keys) {
130 list_del_init(&ep_key->key_list);
131 sctp_auth_shkey_free(ep_key);
132 }
133}
134
135/* Compare two byte vectors as numbers. Return values
136 * are:
137 * 0 - vectors are equal
Frederik Schwarzer025dfda2008-10-16 19:02:37 +0200138 * < 0 - vector 1 is smaller than vector2
139 * > 0 - vector 1 is greater than vector2
Vlad Yasevich1f485642007-10-09 01:15:59 -0700140 *
141 * Algorithm is:
142 * This is performed by selecting the numerically smaller key vector...
143 * If the key vectors are equal as numbers but differ in length ...
144 * the shorter vector is considered smaller
145 *
146 * Examples (with small values):
147 * 000123456789 > 123456789 (first number is longer)
148 * 000123456789 < 234567891 (second number is larger numerically)
149 * 123456789 > 2345678 (first number is both larger & longer)
150 */
151static int sctp_auth_compare_vectors(struct sctp_auth_bytes *vector1,
152 struct sctp_auth_bytes *vector2)
153{
154 int diff;
155 int i;
156 const __u8 *longer;
157
158 diff = vector1->len - vector2->len;
159 if (diff) {
160 longer = (diff > 0) ? vector1->data : vector2->data;
161
162 /* Check to see if the longer number is
163 * lead-zero padded. If it is not, it
164 * is automatically larger numerically.
165 */
wangweidongcb3f8372013-12-23 12:16:50 +0800166 for (i = 0; i < abs(diff); i++) {
Vlad Yasevich1f485642007-10-09 01:15:59 -0700167 if (longer[i] != 0)
168 return diff;
169 }
170 }
171
172 /* lengths are the same, compare numbers */
173 return memcmp(vector1->data, vector2->data, vector1->len);
174}
175
176/*
177 * Create a key vector as described in SCTP-AUTH, Section 6.1
178 * The RANDOM parameter, the CHUNKS parameter and the HMAC-ALGO
179 * parameter sent by each endpoint are concatenated as byte vectors.
180 * These parameters include the parameter type, parameter length, and
181 * the parameter value, but padding is omitted; all padding MUST be
182 * removed from this concatenation before proceeding with further
183 * computation of keys. Parameters which were not sent are simply
184 * omitted from the concatenation process. The resulting two vectors
185 * are called the two key vectors.
186 */
187static struct sctp_auth_bytes *sctp_auth_make_key_vector(
188 sctp_random_param_t *random,
189 sctp_chunks_param_t *chunks,
190 sctp_hmac_algo_param_t *hmacs,
191 gfp_t gfp)
192{
193 struct sctp_auth_bytes *new;
194 __u32 len;
195 __u32 offset = 0;
Daniel Borkmann241448c2013-02-07 01:41:39 +0000196 __u16 random_len, hmacs_len, chunks_len = 0;
Vlad Yasevich1f485642007-10-09 01:15:59 -0700197
Daniel Borkmann241448c2013-02-07 01:41:39 +0000198 random_len = ntohs(random->param_hdr.length);
199 hmacs_len = ntohs(hmacs->param_hdr.length);
200 if (chunks)
201 chunks_len = ntohs(chunks->param_hdr.length);
202
203 len = random_len + hmacs_len + chunks_len;
Vlad Yasevich1f485642007-10-09 01:15:59 -0700204
Daniel Borkmann03536e22013-02-07 23:22:58 +0000205 new = sctp_auth_create_key(len, gfp);
Vlad Yasevich1f485642007-10-09 01:15:59 -0700206 if (!new)
207 return NULL;
208
Daniel Borkmann241448c2013-02-07 01:41:39 +0000209 memcpy(new->data, random, random_len);
210 offset += random_len;
Vlad Yasevich1f485642007-10-09 01:15:59 -0700211
212 if (chunks) {
Daniel Borkmann241448c2013-02-07 01:41:39 +0000213 memcpy(new->data + offset, chunks, chunks_len);
214 offset += chunks_len;
Vlad Yasevich1f485642007-10-09 01:15:59 -0700215 }
216
Daniel Borkmann241448c2013-02-07 01:41:39 +0000217 memcpy(new->data + offset, hmacs, hmacs_len);
Vlad Yasevich1f485642007-10-09 01:15:59 -0700218
219 return new;
220}
221
222
223/* Make a key vector based on our local parameters */
Adrian Bunk8ad7c62b2007-10-26 04:21:23 -0700224static struct sctp_auth_bytes *sctp_auth_make_local_vector(
Vlad Yasevich1f485642007-10-09 01:15:59 -0700225 const struct sctp_association *asoc,
226 gfp_t gfp)
227{
228 return sctp_auth_make_key_vector(
wangweidong26ac8e52013-12-23 12:16:51 +0800229 (sctp_random_param_t *)asoc->c.auth_random,
230 (sctp_chunks_param_t *)asoc->c.auth_chunks,
231 (sctp_hmac_algo_param_t *)asoc->c.auth_hmacs,
Vlad Yasevich1f485642007-10-09 01:15:59 -0700232 gfp);
233}
234
235/* Make a key vector based on peer's parameters */
Adrian Bunk8ad7c62b2007-10-26 04:21:23 -0700236static struct sctp_auth_bytes *sctp_auth_make_peer_vector(
Vlad Yasevich1f485642007-10-09 01:15:59 -0700237 const struct sctp_association *asoc,
238 gfp_t gfp)
239{
240 return sctp_auth_make_key_vector(asoc->peer.peer_random,
241 asoc->peer.peer_chunks,
242 asoc->peer.peer_hmacs,
243 gfp);
244}
245
246
247/* Set the value of the association shared key base on the parameters
248 * given. The algorithm is:
249 * From the endpoint pair shared keys and the key vectors the
250 * association shared keys are computed. This is performed by selecting
251 * the numerically smaller key vector and concatenating it to the
252 * endpoint pair shared key, and then concatenating the numerically
253 * larger key vector to that. The result of the concatenation is the
254 * association shared key.
255 */
256static struct sctp_auth_bytes *sctp_auth_asoc_set_secret(
257 struct sctp_shared_key *ep_key,
258 struct sctp_auth_bytes *first_vector,
259 struct sctp_auth_bytes *last_vector,
260 gfp_t gfp)
261{
262 struct sctp_auth_bytes *secret;
263 __u32 offset = 0;
264 __u32 auth_len;
265
266 auth_len = first_vector->len + last_vector->len;
267 if (ep_key->key)
268 auth_len += ep_key->key->len;
269
270 secret = sctp_auth_create_key(auth_len, gfp);
271 if (!secret)
272 return NULL;
273
274 if (ep_key->key) {
275 memcpy(secret->data, ep_key->key->data, ep_key->key->len);
276 offset += ep_key->key->len;
277 }
278
279 memcpy(secret->data + offset, first_vector->data, first_vector->len);
280 offset += first_vector->len;
281
282 memcpy(secret->data + offset, last_vector->data, last_vector->len);
283
284 return secret;
285}
286
287/* Create an association shared key. Follow the algorithm
288 * described in SCTP-AUTH, Section 6.1
289 */
290static struct sctp_auth_bytes *sctp_auth_asoc_create_secret(
291 const struct sctp_association *asoc,
292 struct sctp_shared_key *ep_key,
293 gfp_t gfp)
294{
295 struct sctp_auth_bytes *local_key_vector;
296 struct sctp_auth_bytes *peer_key_vector;
297 struct sctp_auth_bytes *first_vector,
298 *last_vector;
299 struct sctp_auth_bytes *secret = NULL;
300 int cmp;
301
302
303 /* Now we need to build the key vectors
304 * SCTP-AUTH , Section 6.1
305 * The RANDOM parameter, the CHUNKS parameter and the HMAC-ALGO
306 * parameter sent by each endpoint are concatenated as byte vectors.
307 * These parameters include the parameter type, parameter length, and
308 * the parameter value, but padding is omitted; all padding MUST be
309 * removed from this concatenation before proceeding with further
310 * computation of keys. Parameters which were not sent are simply
311 * omitted from the concatenation process. The resulting two vectors
312 * are called the two key vectors.
313 */
314
315 local_key_vector = sctp_auth_make_local_vector(asoc, gfp);
316 peer_key_vector = sctp_auth_make_peer_vector(asoc, gfp);
317
318 if (!peer_key_vector || !local_key_vector)
319 goto out;
320
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300321 /* Figure out the order in which the key_vectors will be
Vlad Yasevich1f485642007-10-09 01:15:59 -0700322 * added to the endpoint shared key.
323 * SCTP-AUTH, Section 6.1:
324 * This is performed by selecting the numerically smaller key
325 * vector and concatenating it to the endpoint pair shared
326 * key, and then concatenating the numerically larger key
327 * vector to that. If the key vectors are equal as numbers
328 * but differ in length, then the concatenation order is the
329 * endpoint shared key, followed by the shorter key vector,
330 * followed by the longer key vector. Otherwise, the key
331 * vectors are identical, and may be concatenated to the
332 * endpoint pair key in any order.
333 */
334 cmp = sctp_auth_compare_vectors(local_key_vector,
335 peer_key_vector);
336 if (cmp < 0) {
337 first_vector = local_key_vector;
338 last_vector = peer_key_vector;
339 } else {
340 first_vector = peer_key_vector;
341 last_vector = local_key_vector;
342 }
343
344 secret = sctp_auth_asoc_set_secret(ep_key, first_vector, last_vector,
345 gfp);
346out:
Daniel Borkmann03536e22013-02-07 23:22:58 +0000347 sctp_auth_key_put(local_key_vector);
348 sctp_auth_key_put(peer_key_vector);
Vlad Yasevich1f485642007-10-09 01:15:59 -0700349
350 return secret;
351}
352
353/*
354 * Populate the association overlay list with the list
355 * from the endpoint.
356 */
357int sctp_auth_asoc_copy_shkeys(const struct sctp_endpoint *ep,
358 struct sctp_association *asoc,
359 gfp_t gfp)
360{
361 struct sctp_shared_key *sh_key;
362 struct sctp_shared_key *new;
363
364 BUG_ON(!list_empty(&asoc->endpoint_shared_keys));
365
366 key_for_each(sh_key, &ep->endpoint_shared_keys) {
367 new = sctp_auth_shkey_create(sh_key->key_id, gfp);
368 if (!new)
369 goto nomem;
370
371 new->key = sh_key->key;
372 sctp_auth_key_hold(new->key);
373 list_add(&new->key_list, &asoc->endpoint_shared_keys);
374 }
375
376 return 0;
377
378nomem:
379 sctp_auth_destroy_keys(&asoc->endpoint_shared_keys);
380 return -ENOMEM;
381}
382
383
Marcelo Ricardo Leitnerae368062015-06-11 14:49:46 -0300384/* Public interface to create the association shared key.
Vlad Yasevich1f485642007-10-09 01:15:59 -0700385 * See code above for the algorithm.
386 */
387int sctp_auth_asoc_init_active_key(struct sctp_association *asoc, gfp_t gfp)
388{
389 struct sctp_auth_bytes *secret;
390 struct sctp_shared_key *ep_key;
Marcelo Ricardo Leitnerae368062015-06-11 14:49:46 -0300391 struct sctp_chunk *chunk;
Vlad Yasevich1f485642007-10-09 01:15:59 -0700392
393 /* If we don't support AUTH, or peer is not capable
394 * we don't need to do anything.
395 */
Vlad Yasevichb14878c2014-04-17 17:26:50 +0200396 if (!asoc->ep->auth_enable || !asoc->peer.auth_capable)
Vlad Yasevich1f485642007-10-09 01:15:59 -0700397 return 0;
398
399 /* If the key_id is non-zero and we couldn't find an
400 * endpoint pair shared key, we can't compute the
401 * secret.
402 * For key_id 0, endpoint pair shared key is a NULL key.
403 */
404 ep_key = sctp_auth_get_shkey(asoc, asoc->active_key_id);
405 BUG_ON(!ep_key);
406
407 secret = sctp_auth_asoc_create_secret(asoc, ep_key, gfp);
408 if (!secret)
409 return -ENOMEM;
410
411 sctp_auth_key_put(asoc->asoc_shared_key);
412 asoc->asoc_shared_key = secret;
413
Marcelo Ricardo Leitnerae368062015-06-11 14:49:46 -0300414 /* Update send queue in case any chunk already in there now
415 * needs authenticating
416 */
417 list_for_each_entry(chunk, &asoc->outqueue.out_chunk_list, list) {
418 if (sctp_auth_send_cid(chunk->chunk_hdr->type, asoc))
419 chunk->auth = 1;
420 }
421
Vlad Yasevich1f485642007-10-09 01:15:59 -0700422 return 0;
423}
424
425
426/* Find the endpoint pair shared key based on the key_id */
427struct sctp_shared_key *sctp_auth_get_shkey(
428 const struct sctp_association *asoc,
429 __u16 key_id)
430{
Wei Yongjun7cc08b52008-02-05 03:03:06 -0800431 struct sctp_shared_key *key;
Vlad Yasevich1f485642007-10-09 01:15:59 -0700432
433 /* First search associations set of endpoint pair shared keys */
434 key_for_each(key, &asoc->endpoint_shared_keys) {
435 if (key->key_id == key_id)
Wei Yongjun7cc08b52008-02-05 03:03:06 -0800436 return key;
Vlad Yasevich1f485642007-10-09 01:15:59 -0700437 }
438
Wei Yongjun7cc08b52008-02-05 03:03:06 -0800439 return NULL;
Vlad Yasevich1f485642007-10-09 01:15:59 -0700440}
441
442/*
443 * Initialize all the possible digest transforms that we can use. Right now
444 * now, the supported digests are SHA1 and SHA256. We do this here once
445 * because of the restrictiong that transforms may only be allocated in
446 * user context. This forces us to pre-allocated all possible transforms
447 * at the endpoint init time.
448 */
449int sctp_auth_init_hmacs(struct sctp_endpoint *ep, gfp_t gfp)
450{
Herbert Xu5821c762016-01-24 21:20:12 +0800451 struct crypto_shash *tfm = NULL;
Vlad Yasevich1f485642007-10-09 01:15:59 -0700452 __u16 id;
453
Vlad Yasevichb14878c2014-04-17 17:26:50 +0200454 /* If AUTH extension is disabled, we are done */
455 if (!ep->auth_enable) {
Vlad Yasevich1f485642007-10-09 01:15:59 -0700456 ep->auth_hmacs = NULL;
457 return 0;
458 }
459
Vlad Yasevichb14878c2014-04-17 17:26:50 +0200460 /* If the transforms are already allocated, we are done */
Vlad Yasevich1f485642007-10-09 01:15:59 -0700461 if (ep->auth_hmacs)
462 return 0;
463
464 /* Allocated the array of pointers to transorms */
Herbert Xu5821c762016-01-24 21:20:12 +0800465 ep->auth_hmacs = kzalloc(sizeof(struct crypto_shash *) *
466 SCTP_AUTH_NUM_HMACS, gfp);
Vlad Yasevich1f485642007-10-09 01:15:59 -0700467 if (!ep->auth_hmacs)
468 return -ENOMEM;
469
470 for (id = 0; id < SCTP_AUTH_NUM_HMACS; id++) {
471
472 /* See is we support the id. Supported IDs have name and
473 * length fields set, so that we can allocated and use
474 * them. We can safely just check for name, for without the
475 * name, we can't allocate the TFM.
476 */
477 if (!sctp_hmac_list[id].hmac_name)
478 continue;
479
480 /* If this TFM has been allocated, we are all set */
481 if (ep->auth_hmacs[id])
482 continue;
483
484 /* Allocate the ID */
Herbert Xu5821c762016-01-24 21:20:12 +0800485 tfm = crypto_alloc_shash(sctp_hmac_list[id].hmac_name, 0, 0);
Vlad Yasevich1f485642007-10-09 01:15:59 -0700486 if (IS_ERR(tfm))
487 goto out_err;
488
489 ep->auth_hmacs[id] = tfm;
490 }
491
492 return 0;
493
494out_err:
Coly Li73ac36e2009-01-07 18:09:16 -0800495 /* Clean up any successful allocations */
Vlad Yasevich1f485642007-10-09 01:15:59 -0700496 sctp_auth_destroy_hmacs(ep->auth_hmacs);
497 return -ENOMEM;
498}
499
500/* Destroy the hmac tfm array */
Herbert Xu5821c762016-01-24 21:20:12 +0800501void sctp_auth_destroy_hmacs(struct crypto_shash *auth_hmacs[])
Vlad Yasevich1f485642007-10-09 01:15:59 -0700502{
503 int i;
504
505 if (!auth_hmacs)
506 return;
507
wangweidong8d726512013-12-23 12:16:53 +0800508 for (i = 0; i < SCTP_AUTH_NUM_HMACS; i++) {
Herbert Xu5821c762016-01-24 21:20:12 +0800509 crypto_free_shash(auth_hmacs[i]);
Vlad Yasevich1f485642007-10-09 01:15:59 -0700510 }
511 kfree(auth_hmacs);
512}
513
514
515struct sctp_hmac *sctp_auth_get_hmac(__u16 hmac_id)
516{
517 return &sctp_hmac_list[hmac_id];
518}
519
520/* Get an hmac description information that we can use to build
521 * the AUTH chunk
522 */
523struct sctp_hmac *sctp_auth_asoc_get_hmac(const struct sctp_association *asoc)
524{
525 struct sctp_hmac_algo_param *hmacs;
526 __u16 n_elt;
527 __u16 id = 0;
528 int i;
529
530 /* If we have a default entry, use it */
531 if (asoc->default_hmac_id)
532 return &sctp_hmac_list[asoc->default_hmac_id];
533
534 /* Since we do not have a default entry, find the first entry
535 * we support and return that. Do not cache that id.
536 */
537 hmacs = asoc->peer.peer_hmacs;
538 if (!hmacs)
539 return NULL;
540
541 n_elt = (ntohs(hmacs->param_hdr.length) - sizeof(sctp_paramhdr_t)) >> 1;
542 for (i = 0; i < n_elt; i++) {
543 id = ntohs(hmacs->hmac_ids[i]);
544
wangweidong747edc02013-10-26 16:06:32 +0800545 /* Check the id is in the supported range. And
546 * see if we support the id. Supported IDs have name and
547 * length fields set, so that we can allocate and use
Vlad Yasevich1f485642007-10-09 01:15:59 -0700548 * them. We can safely just check for name, for without the
549 * name, we can't allocate the TFM.
550 */
wangweidong747edc02013-10-26 16:06:32 +0800551 if (id > SCTP_AUTH_HMAC_ID_MAX ||
552 !sctp_hmac_list[id].hmac_name) {
Dan Rosenberg51e97a12010-10-01 11:51:47 +0000553 id = 0;
Vlad Yasevich1f485642007-10-09 01:15:59 -0700554 continue;
Dan Rosenberg51e97a12010-10-01 11:51:47 +0000555 }
Vlad Yasevich1f485642007-10-09 01:15:59 -0700556
557 break;
558 }
559
560 if (id == 0)
561 return NULL;
562
563 return &sctp_hmac_list[id];
564}
565
Al Virod06f6082007-10-29 05:03:23 +0000566static int __sctp_auth_find_hmacid(__be16 *hmacs, int n_elts, __be16 hmac_id)
Vlad Yasevich1f485642007-10-09 01:15:59 -0700567{
568 int found = 0;
569 int i;
570
571 for (i = 0; i < n_elts; i++) {
572 if (hmac_id == hmacs[i]) {
573 found = 1;
574 break;
575 }
576 }
577
578 return found;
579}
580
581/* See if the HMAC_ID is one that we claim as supported */
582int sctp_auth_asoc_verify_hmac_id(const struct sctp_association *asoc,
Al Virod06f6082007-10-29 05:03:23 +0000583 __be16 hmac_id)
Vlad Yasevich1f485642007-10-09 01:15:59 -0700584{
585 struct sctp_hmac_algo_param *hmacs;
586 __u16 n_elt;
587
588 if (!asoc)
589 return 0;
590
591 hmacs = (struct sctp_hmac_algo_param *)asoc->c.auth_hmacs;
592 n_elt = (ntohs(hmacs->param_hdr.length) - sizeof(sctp_paramhdr_t)) >> 1;
593
594 return __sctp_auth_find_hmacid(hmacs->hmac_ids, n_elt, hmac_id);
595}
596
597
598/* Cache the default HMAC id. This to follow this text from SCTP-AUTH:
599 * Section 6.1:
600 * The receiver of a HMAC-ALGO parameter SHOULD use the first listed
601 * algorithm it supports.
602 */
603void sctp_auth_asoc_set_default_hmac(struct sctp_association *asoc,
604 struct sctp_hmac_algo_param *hmacs)
605{
606 struct sctp_endpoint *ep;
607 __u16 id;
608 int i;
609 int n_params;
610
611 /* if the default id is already set, use it */
612 if (asoc->default_hmac_id)
613 return;
614
615 n_params = (ntohs(hmacs->param_hdr.length)
616 - sizeof(sctp_paramhdr_t)) >> 1;
617 ep = asoc->ep;
618 for (i = 0; i < n_params; i++) {
619 id = ntohs(hmacs->hmac_ids[i]);
620
621 /* Check the id is in the supported range */
622 if (id > SCTP_AUTH_HMAC_ID_MAX)
623 continue;
624
625 /* If this TFM has been allocated, use this id */
626 if (ep->auth_hmacs[id]) {
627 asoc->default_hmac_id = id;
628 break;
629 }
630 }
631}
632
633
634/* Check to see if the given chunk is supposed to be authenticated */
635static int __sctp_auth_cid(sctp_cid_t chunk, struct sctp_chunks_param *param)
636{
637 unsigned short len;
638 int found = 0;
639 int i;
640
Vlad Yasevich555d3d52007-11-29 08:56:16 -0500641 if (!param || param->param_hdr.length == 0)
Vlad Yasevich1f485642007-10-09 01:15:59 -0700642 return 0;
643
644 len = ntohs(param->param_hdr.length) - sizeof(sctp_paramhdr_t);
645
646 /* SCTP-AUTH, Section 3.2
647 * The chunk types for INIT, INIT-ACK, SHUTDOWN-COMPLETE and AUTH
648 * chunks MUST NOT be listed in the CHUNKS parameter. However, if
649 * a CHUNKS parameter is received then the types for INIT, INIT-ACK,
650 * SHUTDOWN-COMPLETE and AUTH chunks MUST be ignored.
651 */
652 for (i = 0; !found && i < len; i++) {
653 switch (param->chunks[i]) {
wangweidongf7010e62013-12-23 12:16:52 +0800654 case SCTP_CID_INIT:
655 case SCTP_CID_INIT_ACK:
656 case SCTP_CID_SHUTDOWN_COMPLETE:
657 case SCTP_CID_AUTH:
Vlad Yasevich1f485642007-10-09 01:15:59 -0700658 break;
659
wangweidongf7010e62013-12-23 12:16:52 +0800660 default:
Vlad Yasevich1f485642007-10-09 01:15:59 -0700661 if (param->chunks[i] == chunk)
wangweidongf7010e62013-12-23 12:16:52 +0800662 found = 1;
Vlad Yasevich1f485642007-10-09 01:15:59 -0700663 break;
664 }
665 }
666
667 return found;
668}
669
670/* Check if peer requested that this chunk is authenticated */
671int sctp_auth_send_cid(sctp_cid_t chunk, const struct sctp_association *asoc)
672{
Eric W. Biedermane1fc3b12012-08-07 07:29:57 +0000673 if (!asoc)
674 return 0;
675
Vlad Yasevichb14878c2014-04-17 17:26:50 +0200676 if (!asoc->ep->auth_enable || !asoc->peer.auth_capable)
Vlad Yasevich1f485642007-10-09 01:15:59 -0700677 return 0;
678
679 return __sctp_auth_cid(chunk, asoc->peer.peer_chunks);
680}
681
682/* Check if we requested that peer authenticate this chunk. */
683int sctp_auth_recv_cid(sctp_cid_t chunk, const struct sctp_association *asoc)
684{
Eric W. Biedermane1fc3b12012-08-07 07:29:57 +0000685 if (!asoc)
686 return 0;
687
Vlad Yasevichb14878c2014-04-17 17:26:50 +0200688 if (!asoc->ep->auth_enable)
Vlad Yasevich1f485642007-10-09 01:15:59 -0700689 return 0;
690
691 return __sctp_auth_cid(chunk,
692 (struct sctp_chunks_param *)asoc->c.auth_chunks);
693}
694
695/* SCTP-AUTH: Section 6.2:
696 * The sender MUST calculate the MAC as described in RFC2104 [2] using
697 * the hash function H as described by the MAC Identifier and the shared
698 * association key K based on the endpoint pair shared key described by
699 * the shared key identifier. The 'data' used for the computation of
700 * the AUTH-chunk is given by the AUTH chunk with its HMAC field set to
701 * zero (as shown in Figure 6) followed by all chunks that are placed
702 * after the AUTH chunk in the SCTP packet.
703 */
704void sctp_auth_calculate_hmac(const struct sctp_association *asoc,
705 struct sk_buff *skb,
706 struct sctp_auth_chunk *auth,
707 gfp_t gfp)
708{
Herbert Xu5821c762016-01-24 21:20:12 +0800709 struct crypto_shash *tfm;
Vlad Yasevich1f485642007-10-09 01:15:59 -0700710 struct sctp_auth_bytes *asoc_key;
711 __u16 key_id, hmac_id;
712 __u8 *digest;
713 unsigned char *end;
714 int free_key = 0;
715
716 /* Extract the info we need:
717 * - hmac id
718 * - key id
719 */
720 key_id = ntohs(auth->auth_hdr.shkey_id);
721 hmac_id = ntohs(auth->auth_hdr.hmac_id);
722
723 if (key_id == asoc->active_key_id)
724 asoc_key = asoc->asoc_shared_key;
725 else {
726 struct sctp_shared_key *ep_key;
727
728 ep_key = sctp_auth_get_shkey(asoc, key_id);
729 if (!ep_key)
730 return;
731
732 asoc_key = sctp_auth_asoc_create_secret(asoc, ep_key, gfp);
733 if (!asoc_key)
734 return;
735
736 free_key = 1;
737 }
738
739 /* set up scatter list */
740 end = skb_tail_pointer(skb);
Vlad Yasevich1f485642007-10-09 01:15:59 -0700741
Herbert Xu5821c762016-01-24 21:20:12 +0800742 tfm = asoc->ep->auth_hmacs[hmac_id];
Vlad Yasevich1f485642007-10-09 01:15:59 -0700743
744 digest = auth->auth_hdr.hmac;
Herbert Xu5821c762016-01-24 21:20:12 +0800745 if (crypto_shash_setkey(tfm, &asoc_key->data[0], asoc_key->len))
Vlad Yasevich1f485642007-10-09 01:15:59 -0700746 goto free;
747
Herbert Xu5821c762016-01-24 21:20:12 +0800748 {
749 SHASH_DESC_ON_STACK(desc, tfm);
750
751 desc->tfm = tfm;
752 desc->flags = 0;
753 crypto_shash_digest(desc, (u8 *)auth,
754 end - (unsigned char *)auth, digest);
755 shash_desc_zero(desc);
756 }
Vlad Yasevich1f485642007-10-09 01:15:59 -0700757
758free:
759 if (free_key)
760 sctp_auth_key_put(asoc_key);
761}
Vlad Yasevich65b07e52007-09-16 19:34:00 -0700762
763/* API Helpers */
764
765/* Add a chunk to the endpoint authenticated chunk list */
766int sctp_auth_ep_add_chunkid(struct sctp_endpoint *ep, __u8 chunk_id)
767{
768 struct sctp_chunks_param *p = ep->auth_chunk_list;
769 __u16 nchunks;
770 __u16 param_len;
771
772 /* If this chunk is already specified, we are done */
773 if (__sctp_auth_cid(chunk_id, p))
774 return 0;
775
776 /* Check if we can add this chunk to the array */
777 param_len = ntohs(p->param_hdr.length);
778 nchunks = param_len - sizeof(sctp_paramhdr_t);
779 if (nchunks == SCTP_NUM_CHUNK_TYPES)
780 return -EINVAL;
781
782 p->chunks[nchunks] = chunk_id;
783 p->param_hdr.length = htons(param_len + 1);
784 return 0;
785}
786
787/* Add hmac identifires to the endpoint list of supported hmac ids */
788int sctp_auth_ep_set_hmacs(struct sctp_endpoint *ep,
789 struct sctp_hmacalgo *hmacs)
790{
791 int has_sha1 = 0;
792 __u16 id;
793 int i;
794
795 /* Scan the list looking for unsupported id. Also make sure that
796 * SHA1 is specified.
797 */
798 for (i = 0; i < hmacs->shmac_num_idents; i++) {
799 id = hmacs->shmac_idents[i];
800
Vlad Yasevichd9724052008-08-27 16:09:49 -0700801 if (id > SCTP_AUTH_HMAC_ID_MAX)
802 return -EOPNOTSUPP;
803
Vlad Yasevich65b07e52007-09-16 19:34:00 -0700804 if (SCTP_AUTH_HMAC_ID_SHA1 == id)
805 has_sha1 = 1;
806
807 if (!sctp_hmac_list[id].hmac_name)
808 return -EOPNOTSUPP;
809 }
810
811 if (!has_sha1)
812 return -EINVAL;
813
luciened5a3772015-11-12 13:07:07 +0800814 for (i = 0; i < hmacs->shmac_num_idents; i++)
815 ep->auth_hmacs_list->hmac_ids[i] = htons(hmacs->shmac_idents[i]);
Vlad Yasevich65b07e52007-09-16 19:34:00 -0700816 ep->auth_hmacs_list->param_hdr.length = htons(sizeof(sctp_paramhdr_t) +
817 hmacs->shmac_num_idents * sizeof(__u16));
818 return 0;
819}
820
821/* Set a new shared key on either endpoint or association. If the
822 * the key with a same ID already exists, replace the key (remove the
823 * old key and add a new one).
824 */
825int sctp_auth_set_key(struct sctp_endpoint *ep,
826 struct sctp_association *asoc,
827 struct sctp_authkey *auth_key)
828{
829 struct sctp_shared_key *cur_key = NULL;
830 struct sctp_auth_bytes *key;
831 struct list_head *sh_keys;
832 int replace = 0;
833
834 /* Try to find the given key id to see if
835 * we are doing a replace, or adding a new key
836 */
837 if (asoc)
838 sh_keys = &asoc->endpoint_shared_keys;
839 else
840 sh_keys = &ep->endpoint_shared_keys;
841
842 key_for_each(cur_key, sh_keys) {
843 if (cur_key->key_id == auth_key->sca_keynumber) {
844 replace = 1;
845 break;
846 }
847 }
848
849 /* If we are not replacing a key id, we need to allocate
850 * a shared key.
851 */
852 if (!replace) {
853 cur_key = sctp_auth_shkey_create(auth_key->sca_keynumber,
854 GFP_KERNEL);
855 if (!cur_key)
856 return -ENOMEM;
857 }
858
859 /* Create a new key data based on the info passed in */
Vlad Yasevich7e8616d2008-02-27 16:04:52 -0500860 key = sctp_auth_create_key(auth_key->sca_keylength, GFP_KERNEL);
Vlad Yasevich65b07e52007-09-16 19:34:00 -0700861 if (!key)
862 goto nomem;
863
Vlad Yasevich7e8616d2008-02-27 16:04:52 -0500864 memcpy(key->data, &auth_key->sca_key[0], auth_key->sca_keylength);
Vlad Yasevich65b07e52007-09-16 19:34:00 -0700865
866 /* If we are replacing, remove the old keys data from the
867 * key id. If we are adding new key id, add it to the
868 * list.
869 */
870 if (replace)
871 sctp_auth_key_put(cur_key->key);
872 else
873 list_add(&cur_key->key_list, sh_keys);
874
875 cur_key->key = key;
Vlad Yasevich65b07e52007-09-16 19:34:00 -0700876 return 0;
877nomem:
878 if (!replace)
879 sctp_auth_shkey_free(cur_key);
880
881 return -ENOMEM;
882}
883
884int sctp_auth_set_active_key(struct sctp_endpoint *ep,
885 struct sctp_association *asoc,
886 __u16 key_id)
887{
888 struct sctp_shared_key *key;
889 struct list_head *sh_keys;
890 int found = 0;
891
892 /* The key identifier MUST correst to an existing key */
893 if (asoc)
894 sh_keys = &asoc->endpoint_shared_keys;
895 else
896 sh_keys = &ep->endpoint_shared_keys;
897
898 key_for_each(key, sh_keys) {
899 if (key->key_id == key_id) {
900 found = 1;
901 break;
902 }
903 }
904
905 if (!found)
906 return -EINVAL;
907
908 if (asoc) {
909 asoc->active_key_id = key_id;
910 sctp_auth_asoc_init_active_key(asoc, GFP_KERNEL);
911 } else
912 ep->active_key_id = key_id;
913
914 return 0;
915}
916
917int sctp_auth_del_key_id(struct sctp_endpoint *ep,
918 struct sctp_association *asoc,
919 __u16 key_id)
920{
921 struct sctp_shared_key *key;
922 struct list_head *sh_keys;
923 int found = 0;
924
925 /* The key identifier MUST NOT be the current active key
926 * The key identifier MUST correst to an existing key
927 */
928 if (asoc) {
929 if (asoc->active_key_id == key_id)
930 return -EINVAL;
931
932 sh_keys = &asoc->endpoint_shared_keys;
933 } else {
934 if (ep->active_key_id == key_id)
935 return -EINVAL;
936
937 sh_keys = &ep->endpoint_shared_keys;
938 }
939
940 key_for_each(key, sh_keys) {
941 if (key->key_id == key_id) {
942 found = 1;
943 break;
944 }
945 }
946
947 if (!found)
948 return -EINVAL;
949
950 /* Delete the shared key */
951 list_del_init(&key->key_list);
952 sctp_auth_shkey_free(key);
953
954 return 0;
955}