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60c778b2 | 1 | /* SCTP kernel implementation |
1f485649 VY |
2 | * (C) Copyright 2007 Hewlett-Packard Development Company, L.P. |
3 | * | |
60c778b2 | 4 | * This file is part of the SCTP kernel implementation |
1f485649 | 5 | * |
60c778b2 | 6 | * This SCTP implementation is free software; |
1f485649 VY |
7 | * 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 | * | |
60c778b2 | 12 | * This SCTP implementation is distributed in the hope that it |
1f485649 VY |
13 | * 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 | |
4b2f13a2 JK |
19 | * along with GNU CC; see the file COPYING. If not, see |
20 | * <http://www.gnu.org/licenses/>. | |
1f485649 VY |
21 | * |
22 | * Please send any bug reports or fixes you make to the | |
23 | * email address(es): | |
91705c61 | 24 | * lksctp developers <linux-sctp@vger.kernel.org> |
1f485649 | 25 | * |
1f485649 VY |
26 | * Written or modified by: |
27 | * Vlad Yasevich <vladislav.yasevich@hp.com> | |
1f485649 VY |
28 | */ |
29 | ||
5821c769 | 30 | #include <crypto/hash.h> |
5a0e3ad6 | 31 | #include <linux/slab.h> |
1f485649 | 32 | #include <linux/types.h> |
1f485649 VY |
33 | #include <linux/scatterlist.h> |
34 | #include <net/sctp/sctp.h> | |
35 | #include <net/sctp/auth.h> | |
36 | ||
37 | static 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, | |
cb3f837b | 44 | .hmac_name = "hmac(sha1)", |
1f485649 VY |
45 | .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 | }, | |
aebf5de0 | 51 | #if IS_ENABLED(CONFIG_CRYPTO_SHA256) |
1f485649 VY |
52 | { |
53 | .hmac_id = SCTP_AUTH_HMAC_ID_SHA256, | |
cb3f837b | 54 | .hmac_name = "hmac(sha256)", |
1f485649 VY |
55 | .hmac_len = SCTP_SHA256_SIG_SIZE, |
56 | } | |
b7e0fe9f | 57 | #endif |
1f485649 VY |
58 | }; |
59 | ||
60 | ||
61 | void sctp_auth_key_put(struct sctp_auth_bytes *key) | |
62 | { | |
63 | if (!key) | |
64 | return; | |
65 | ||
6871584a | 66 | if (refcount_dec_and_test(&key->refcnt)) { |
586c31f3 | 67 | kzfree(key); |
1f485649 VY |
68 | SCTP_DBG_OBJCNT_DEC(keys); |
69 | } | |
70 | } | |
71 | ||
72 | /* Create a new key structure of a given length */ | |
73 | static struct sctp_auth_bytes *sctp_auth_create_key(__u32 key_len, gfp_t gfp) | |
74 | { | |
75 | struct sctp_auth_bytes *key; | |
76 | ||
30c2235c | 77 | /* Verify that we are not going to overflow INT_MAX */ |
c89304b8 | 78 | if (key_len > (INT_MAX - sizeof(struct sctp_auth_bytes))) |
30c2235c VY |
79 | return NULL; |
80 | ||
1f485649 VY |
81 | /* 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; | |
6871584a | 87 | refcount_set(&key->refcnt, 1); |
1f485649 VY |
88 | SCTP_DBG_OBJCNT_INC(keys); |
89 | ||
90 | return key; | |
91 | } | |
92 | ||
93 | /* Create a new shared key container with a give key id */ | |
94 | struct 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); | |
1b1e0bc9 | 104 | refcount_set(&new->refcnt, 1); |
1f485649 VY |
105 | new->key_id = key_id; |
106 | ||
107 | return new; | |
108 | } | |
109 | ||
25985edc | 110 | /* Free the shared key structure */ |
1b1e0bc9 | 111 | static void sctp_auth_shkey_destroy(struct sctp_shared_key *sh_key) |
1f485649 VY |
112 | { |
113 | BUG_ON(!list_empty(&sh_key->key_list)); | |
114 | sctp_auth_key_put(sh_key->key); | |
115 | sh_key->key = NULL; | |
116 | kfree(sh_key); | |
117 | } | |
118 | ||
1b1e0bc9 XL |
119 | void sctp_auth_shkey_release(struct sctp_shared_key *sh_key) |
120 | { | |
121 | if (refcount_dec_and_test(&sh_key->refcnt)) | |
122 | sctp_auth_shkey_destroy(sh_key); | |
123 | } | |
124 | ||
125 | void sctp_auth_shkey_hold(struct sctp_shared_key *sh_key) | |
126 | { | |
127 | refcount_inc(&sh_key->refcnt); | |
128 | } | |
129 | ||
25985edc | 130 | /* Destroy the entire key list. This is done during the |
1f485649 VY |
131 | * associon and endpoint free process. |
132 | */ | |
133 | void sctp_auth_destroy_keys(struct list_head *keys) | |
134 | { | |
135 | struct sctp_shared_key *ep_key; | |
136 | struct sctp_shared_key *tmp; | |
137 | ||
138 | if (list_empty(keys)) | |
139 | return; | |
140 | ||
141 | key_for_each_safe(ep_key, tmp, keys) { | |
142 | list_del_init(&ep_key->key_list); | |
1b1e0bc9 | 143 | sctp_auth_shkey_release(ep_key); |
1f485649 VY |
144 | } |
145 | } | |
146 | ||
147 | /* Compare two byte vectors as numbers. Return values | |
148 | * are: | |
149 | * 0 - vectors are equal | |
025dfdaf FS |
150 | * < 0 - vector 1 is smaller than vector2 |
151 | * > 0 - vector 1 is greater than vector2 | |
1f485649 VY |
152 | * |
153 | * Algorithm is: | |
154 | * This is performed by selecting the numerically smaller key vector... | |
155 | * If the key vectors are equal as numbers but differ in length ... | |
156 | * the shorter vector is considered smaller | |
157 | * | |
158 | * Examples (with small values): | |
159 | * 000123456789 > 123456789 (first number is longer) | |
160 | * 000123456789 < 234567891 (second number is larger numerically) | |
161 | * 123456789 > 2345678 (first number is both larger & longer) | |
162 | */ | |
163 | static int sctp_auth_compare_vectors(struct sctp_auth_bytes *vector1, | |
164 | struct sctp_auth_bytes *vector2) | |
165 | { | |
166 | int diff; | |
167 | int i; | |
168 | const __u8 *longer; | |
169 | ||
170 | diff = vector1->len - vector2->len; | |
171 | if (diff) { | |
172 | longer = (diff > 0) ? vector1->data : vector2->data; | |
173 | ||
174 | /* Check to see if the longer number is | |
175 | * lead-zero padded. If it is not, it | |
176 | * is automatically larger numerically. | |
177 | */ | |
cb3f837b | 178 | for (i = 0; i < abs(diff); i++) { |
1f485649 VY |
179 | if (longer[i] != 0) |
180 | return diff; | |
181 | } | |
182 | } | |
183 | ||
184 | /* lengths are the same, compare numbers */ | |
185 | return memcmp(vector1->data, vector2->data, vector1->len); | |
186 | } | |
187 | ||
188 | /* | |
189 | * Create a key vector as described in SCTP-AUTH, Section 6.1 | |
190 | * The RANDOM parameter, the CHUNKS parameter and the HMAC-ALGO | |
191 | * parameter sent by each endpoint are concatenated as byte vectors. | |
192 | * These parameters include the parameter type, parameter length, and | |
193 | * the parameter value, but padding is omitted; all padding MUST be | |
194 | * removed from this concatenation before proceeding with further | |
195 | * computation of keys. Parameters which were not sent are simply | |
196 | * omitted from the concatenation process. The resulting two vectors | |
197 | * are called the two key vectors. | |
198 | */ | |
199 | static struct sctp_auth_bytes *sctp_auth_make_key_vector( | |
b02db702 | 200 | struct sctp_random_param *random, |
a762a9d9 | 201 | struct sctp_chunks_param *chunks, |
1474774a | 202 | struct sctp_hmac_algo_param *hmacs, |
1f485649 VY |
203 | gfp_t gfp) |
204 | { | |
205 | struct sctp_auth_bytes *new; | |
206 | __u32 len; | |
207 | __u32 offset = 0; | |
241448c2 | 208 | __u16 random_len, hmacs_len, chunks_len = 0; |
1f485649 | 209 | |
241448c2 DB |
210 | random_len = ntohs(random->param_hdr.length); |
211 | hmacs_len = ntohs(hmacs->param_hdr.length); | |
212 | if (chunks) | |
213 | chunks_len = ntohs(chunks->param_hdr.length); | |
214 | ||
215 | len = random_len + hmacs_len + chunks_len; | |
1f485649 | 216 | |
03536e23 | 217 | new = sctp_auth_create_key(len, gfp); |
1f485649 VY |
218 | if (!new) |
219 | return NULL; | |
220 | ||
241448c2 DB |
221 | memcpy(new->data, random, random_len); |
222 | offset += random_len; | |
1f485649 VY |
223 | |
224 | if (chunks) { | |
241448c2 DB |
225 | memcpy(new->data + offset, chunks, chunks_len); |
226 | offset += chunks_len; | |
1f485649 VY |
227 | } |
228 | ||
241448c2 | 229 | memcpy(new->data + offset, hmacs, hmacs_len); |
1f485649 VY |
230 | |
231 | return new; | |
232 | } | |
233 | ||
234 | ||
235 | /* Make a key vector based on our local parameters */ | |
8ad7c62b | 236 | static struct sctp_auth_bytes *sctp_auth_make_local_vector( |
1f485649 VY |
237 | const struct sctp_association *asoc, |
238 | gfp_t gfp) | |
239 | { | |
240 | return sctp_auth_make_key_vector( | |
b02db702 | 241 | (struct sctp_random_param *)asoc->c.auth_random, |
a762a9d9 | 242 | (struct sctp_chunks_param *)asoc->c.auth_chunks, |
1474774a | 243 | (struct sctp_hmac_algo_param *)asoc->c.auth_hmacs, gfp); |
1f485649 VY |
244 | } |
245 | ||
246 | /* Make a key vector based on peer's parameters */ | |
8ad7c62b | 247 | static struct sctp_auth_bytes *sctp_auth_make_peer_vector( |
1f485649 VY |
248 | const struct sctp_association *asoc, |
249 | gfp_t gfp) | |
250 | { | |
251 | return sctp_auth_make_key_vector(asoc->peer.peer_random, | |
252 | asoc->peer.peer_chunks, | |
253 | asoc->peer.peer_hmacs, | |
254 | gfp); | |
255 | } | |
256 | ||
257 | ||
258 | /* Set the value of the association shared key base on the parameters | |
259 | * given. The algorithm is: | |
260 | * From the endpoint pair shared keys and the key vectors the | |
261 | * association shared keys are computed. This is performed by selecting | |
262 | * the numerically smaller key vector and concatenating it to the | |
263 | * endpoint pair shared key, and then concatenating the numerically | |
264 | * larger key vector to that. The result of the concatenation is the | |
265 | * association shared key. | |
266 | */ | |
267 | static struct sctp_auth_bytes *sctp_auth_asoc_set_secret( | |
268 | struct sctp_shared_key *ep_key, | |
269 | struct sctp_auth_bytes *first_vector, | |
270 | struct sctp_auth_bytes *last_vector, | |
271 | gfp_t gfp) | |
272 | { | |
273 | struct sctp_auth_bytes *secret; | |
274 | __u32 offset = 0; | |
275 | __u32 auth_len; | |
276 | ||
277 | auth_len = first_vector->len + last_vector->len; | |
278 | if (ep_key->key) | |
279 | auth_len += ep_key->key->len; | |
280 | ||
281 | secret = sctp_auth_create_key(auth_len, gfp); | |
282 | if (!secret) | |
283 | return NULL; | |
284 | ||
285 | if (ep_key->key) { | |
286 | memcpy(secret->data, ep_key->key->data, ep_key->key->len); | |
287 | offset += ep_key->key->len; | |
288 | } | |
289 | ||
290 | memcpy(secret->data + offset, first_vector->data, first_vector->len); | |
291 | offset += first_vector->len; | |
292 | ||
293 | memcpy(secret->data + offset, last_vector->data, last_vector->len); | |
294 | ||
295 | return secret; | |
296 | } | |
297 | ||
298 | /* Create an association shared key. Follow the algorithm | |
299 | * described in SCTP-AUTH, Section 6.1 | |
300 | */ | |
301 | static struct sctp_auth_bytes *sctp_auth_asoc_create_secret( | |
302 | const struct sctp_association *asoc, | |
303 | struct sctp_shared_key *ep_key, | |
304 | gfp_t gfp) | |
305 | { | |
306 | struct sctp_auth_bytes *local_key_vector; | |
307 | struct sctp_auth_bytes *peer_key_vector; | |
308 | struct sctp_auth_bytes *first_vector, | |
309 | *last_vector; | |
310 | struct sctp_auth_bytes *secret = NULL; | |
311 | int cmp; | |
312 | ||
313 | ||
314 | /* Now we need to build the key vectors | |
315 | * SCTP-AUTH , Section 6.1 | |
316 | * The RANDOM parameter, the CHUNKS parameter and the HMAC-ALGO | |
317 | * parameter sent by each endpoint are concatenated as byte vectors. | |
318 | * These parameters include the parameter type, parameter length, and | |
319 | * the parameter value, but padding is omitted; all padding MUST be | |
320 | * removed from this concatenation before proceeding with further | |
321 | * computation of keys. Parameters which were not sent are simply | |
322 | * omitted from the concatenation process. The resulting two vectors | |
323 | * are called the two key vectors. | |
324 | */ | |
325 | ||
326 | local_key_vector = sctp_auth_make_local_vector(asoc, gfp); | |
327 | peer_key_vector = sctp_auth_make_peer_vector(asoc, gfp); | |
328 | ||
329 | if (!peer_key_vector || !local_key_vector) | |
330 | goto out; | |
331 | ||
25985edc | 332 | /* Figure out the order in which the key_vectors will be |
1f485649 VY |
333 | * added to the endpoint shared key. |
334 | * SCTP-AUTH, Section 6.1: | |
335 | * This is performed by selecting the numerically smaller key | |
336 | * vector and concatenating it to the endpoint pair shared | |
337 | * key, and then concatenating the numerically larger key | |
338 | * vector to that. If the key vectors are equal as numbers | |
339 | * but differ in length, then the concatenation order is the | |
340 | * endpoint shared key, followed by the shorter key vector, | |
341 | * followed by the longer key vector. Otherwise, the key | |
342 | * vectors are identical, and may be concatenated to the | |
343 | * endpoint pair key in any order. | |
344 | */ | |
345 | cmp = sctp_auth_compare_vectors(local_key_vector, | |
346 | peer_key_vector); | |
347 | if (cmp < 0) { | |
348 | first_vector = local_key_vector; | |
349 | last_vector = peer_key_vector; | |
350 | } else { | |
351 | first_vector = peer_key_vector; | |
352 | last_vector = local_key_vector; | |
353 | } | |
354 | ||
355 | secret = sctp_auth_asoc_set_secret(ep_key, first_vector, last_vector, | |
356 | gfp); | |
357 | out: | |
03536e23 DB |
358 | sctp_auth_key_put(local_key_vector); |
359 | sctp_auth_key_put(peer_key_vector); | |
1f485649 VY |
360 | |
361 | return secret; | |
362 | } | |
363 | ||
364 | /* | |
365 | * Populate the association overlay list with the list | |
366 | * from the endpoint. | |
367 | */ | |
368 | int sctp_auth_asoc_copy_shkeys(const struct sctp_endpoint *ep, | |
369 | struct sctp_association *asoc, | |
370 | gfp_t gfp) | |
371 | { | |
372 | struct sctp_shared_key *sh_key; | |
373 | struct sctp_shared_key *new; | |
374 | ||
375 | BUG_ON(!list_empty(&asoc->endpoint_shared_keys)); | |
376 | ||
377 | key_for_each(sh_key, &ep->endpoint_shared_keys) { | |
378 | new = sctp_auth_shkey_create(sh_key->key_id, gfp); | |
379 | if (!new) | |
380 | goto nomem; | |
381 | ||
382 | new->key = sh_key->key; | |
383 | sctp_auth_key_hold(new->key); | |
384 | list_add(&new->key_list, &asoc->endpoint_shared_keys); | |
385 | } | |
386 | ||
387 | return 0; | |
388 | ||
389 | nomem: | |
390 | sctp_auth_destroy_keys(&asoc->endpoint_shared_keys); | |
391 | return -ENOMEM; | |
392 | } | |
393 | ||
394 | ||
ae36806a | 395 | /* Public interface to create the association shared key. |
1f485649 VY |
396 | * See code above for the algorithm. |
397 | */ | |
398 | int sctp_auth_asoc_init_active_key(struct sctp_association *asoc, gfp_t gfp) | |
399 | { | |
400 | struct sctp_auth_bytes *secret; | |
401 | struct sctp_shared_key *ep_key; | |
ae36806a | 402 | struct sctp_chunk *chunk; |
1f485649 VY |
403 | |
404 | /* If we don't support AUTH, or peer is not capable | |
405 | * we don't need to do anything. | |
406 | */ | |
b14878cc | 407 | if (!asoc->ep->auth_enable || !asoc->peer.auth_capable) |
1f485649 VY |
408 | return 0; |
409 | ||
410 | /* If the key_id is non-zero and we couldn't find an | |
411 | * endpoint pair shared key, we can't compute the | |
412 | * secret. | |
413 | * For key_id 0, endpoint pair shared key is a NULL key. | |
414 | */ | |
415 | ep_key = sctp_auth_get_shkey(asoc, asoc->active_key_id); | |
416 | BUG_ON(!ep_key); | |
417 | ||
418 | secret = sctp_auth_asoc_create_secret(asoc, ep_key, gfp); | |
419 | if (!secret) | |
420 | return -ENOMEM; | |
421 | ||
422 | sctp_auth_key_put(asoc->asoc_shared_key); | |
423 | asoc->asoc_shared_key = secret; | |
1b1e0bc9 | 424 | asoc->shkey = ep_key; |
1f485649 | 425 | |
ae36806a MRL |
426 | /* Update send queue in case any chunk already in there now |
427 | * needs authenticating | |
428 | */ | |
429 | list_for_each_entry(chunk, &asoc->outqueue.out_chunk_list, list) { | |
1b1e0bc9 | 430 | if (sctp_auth_send_cid(chunk->chunk_hdr->type, asoc)) { |
ae36806a | 431 | chunk->auth = 1; |
1b1e0bc9 XL |
432 | if (!chunk->shkey) { |
433 | chunk->shkey = asoc->shkey; | |
434 | sctp_auth_shkey_hold(chunk->shkey); | |
435 | } | |
436 | } | |
ae36806a MRL |
437 | } |
438 | ||
1f485649 VY |
439 | return 0; |
440 | } | |
441 | ||
442 | ||
443 | /* Find the endpoint pair shared key based on the key_id */ | |
444 | struct sctp_shared_key *sctp_auth_get_shkey( | |
445 | const struct sctp_association *asoc, | |
446 | __u16 key_id) | |
447 | { | |
7cc08b55 | 448 | struct sctp_shared_key *key; |
1f485649 VY |
449 | |
450 | /* First search associations set of endpoint pair shared keys */ | |
451 | key_for_each(key, &asoc->endpoint_shared_keys) { | |
601590ec XL |
452 | if (key->key_id == key_id) { |
453 | if (!key->deactivated) | |
454 | return key; | |
455 | break; | |
456 | } | |
1f485649 VY |
457 | } |
458 | ||
7cc08b55 | 459 | return NULL; |
1f485649 VY |
460 | } |
461 | ||
462 | /* | |
463 | * Initialize all the possible digest transforms that we can use. Right now | |
464 | * now, the supported digests are SHA1 and SHA256. We do this here once | |
465 | * because of the restrictiong that transforms may only be allocated in | |
466 | * user context. This forces us to pre-allocated all possible transforms | |
467 | * at the endpoint init time. | |
468 | */ | |
469 | int sctp_auth_init_hmacs(struct sctp_endpoint *ep, gfp_t gfp) | |
470 | { | |
5821c769 | 471 | struct crypto_shash *tfm = NULL; |
1f485649 VY |
472 | __u16 id; |
473 | ||
b14878cc | 474 | /* If the transforms are already allocated, we are done */ |
1f485649 VY |
475 | if (ep->auth_hmacs) |
476 | return 0; | |
477 | ||
478 | /* Allocated the array of pointers to transorms */ | |
6396bb22 KC |
479 | ep->auth_hmacs = kcalloc(SCTP_AUTH_NUM_HMACS, |
480 | sizeof(struct crypto_shash *), | |
481 | gfp); | |
1f485649 VY |
482 | if (!ep->auth_hmacs) |
483 | return -ENOMEM; | |
484 | ||
485 | for (id = 0; id < SCTP_AUTH_NUM_HMACS; id++) { | |
486 | ||
487 | /* See is we support the id. Supported IDs have name and | |
488 | * length fields set, so that we can allocated and use | |
489 | * them. We can safely just check for name, for without the | |
490 | * name, we can't allocate the TFM. | |
491 | */ | |
492 | if (!sctp_hmac_list[id].hmac_name) | |
493 | continue; | |
494 | ||
495 | /* If this TFM has been allocated, we are all set */ | |
496 | if (ep->auth_hmacs[id]) | |
497 | continue; | |
498 | ||
499 | /* Allocate the ID */ | |
5821c769 | 500 | tfm = crypto_alloc_shash(sctp_hmac_list[id].hmac_name, 0, 0); |
1f485649 VY |
501 | if (IS_ERR(tfm)) |
502 | goto out_err; | |
503 | ||
504 | ep->auth_hmacs[id] = tfm; | |
505 | } | |
506 | ||
507 | return 0; | |
508 | ||
509 | out_err: | |
73ac36ea | 510 | /* Clean up any successful allocations */ |
1f485649 VY |
511 | sctp_auth_destroy_hmacs(ep->auth_hmacs); |
512 | return -ENOMEM; | |
513 | } | |
514 | ||
515 | /* Destroy the hmac tfm array */ | |
5821c769 | 516 | void sctp_auth_destroy_hmacs(struct crypto_shash *auth_hmacs[]) |
1f485649 VY |
517 | { |
518 | int i; | |
519 | ||
520 | if (!auth_hmacs) | |
521 | return; | |
522 | ||
8d72651d | 523 | for (i = 0; i < SCTP_AUTH_NUM_HMACS; i++) { |
5821c769 | 524 | crypto_free_shash(auth_hmacs[i]); |
1f485649 VY |
525 | } |
526 | kfree(auth_hmacs); | |
527 | } | |
528 | ||
529 | ||
530 | struct sctp_hmac *sctp_auth_get_hmac(__u16 hmac_id) | |
531 | { | |
532 | return &sctp_hmac_list[hmac_id]; | |
533 | } | |
534 | ||
535 | /* Get an hmac description information that we can use to build | |
536 | * the AUTH chunk | |
537 | */ | |
538 | struct sctp_hmac *sctp_auth_asoc_get_hmac(const struct sctp_association *asoc) | |
539 | { | |
540 | struct sctp_hmac_algo_param *hmacs; | |
541 | __u16 n_elt; | |
542 | __u16 id = 0; | |
543 | int i; | |
544 | ||
545 | /* If we have a default entry, use it */ | |
546 | if (asoc->default_hmac_id) | |
547 | return &sctp_hmac_list[asoc->default_hmac_id]; | |
548 | ||
549 | /* Since we do not have a default entry, find the first entry | |
550 | * we support and return that. Do not cache that id. | |
551 | */ | |
552 | hmacs = asoc->peer.peer_hmacs; | |
553 | if (!hmacs) | |
554 | return NULL; | |
555 | ||
3c918704 XL |
556 | n_elt = (ntohs(hmacs->param_hdr.length) - |
557 | sizeof(struct sctp_paramhdr)) >> 1; | |
1f485649 VY |
558 | for (i = 0; i < n_elt; i++) { |
559 | id = ntohs(hmacs->hmac_ids[i]); | |
560 | ||
747edc0f | 561 | /* Check the id is in the supported range. And |
562 | * see if we support the id. Supported IDs have name and | |
563 | * length fields set, so that we can allocate and use | |
1f485649 VY |
564 | * them. We can safely just check for name, for without the |
565 | * name, we can't allocate the TFM. | |
566 | */ | |
747edc0f | 567 | if (id > SCTP_AUTH_HMAC_ID_MAX || |
568 | !sctp_hmac_list[id].hmac_name) { | |
51e97a12 | 569 | id = 0; |
1f485649 | 570 | continue; |
51e97a12 | 571 | } |
1f485649 VY |
572 | |
573 | break; | |
574 | } | |
575 | ||
576 | if (id == 0) | |
577 | return NULL; | |
578 | ||
579 | return &sctp_hmac_list[id]; | |
580 | } | |
581 | ||
d06f6082 | 582 | static int __sctp_auth_find_hmacid(__be16 *hmacs, int n_elts, __be16 hmac_id) |
1f485649 VY |
583 | { |
584 | int found = 0; | |
585 | int i; | |
586 | ||
587 | for (i = 0; i < n_elts; i++) { | |
588 | if (hmac_id == hmacs[i]) { | |
589 | found = 1; | |
590 | break; | |
591 | } | |
592 | } | |
593 | ||
594 | return found; | |
595 | } | |
596 | ||
597 | /* See if the HMAC_ID is one that we claim as supported */ | |
598 | int sctp_auth_asoc_verify_hmac_id(const struct sctp_association *asoc, | |
d06f6082 | 599 | __be16 hmac_id) |
1f485649 VY |
600 | { |
601 | struct sctp_hmac_algo_param *hmacs; | |
602 | __u16 n_elt; | |
603 | ||
604 | if (!asoc) | |
605 | return 0; | |
606 | ||
607 | hmacs = (struct sctp_hmac_algo_param *)asoc->c.auth_hmacs; | |
3c918704 XL |
608 | n_elt = (ntohs(hmacs->param_hdr.length) - |
609 | sizeof(struct sctp_paramhdr)) >> 1; | |
1f485649 VY |
610 | |
611 | return __sctp_auth_find_hmacid(hmacs->hmac_ids, n_elt, hmac_id); | |
612 | } | |
613 | ||
614 | ||
615 | /* Cache the default HMAC id. This to follow this text from SCTP-AUTH: | |
616 | * Section 6.1: | |
617 | * The receiver of a HMAC-ALGO parameter SHOULD use the first listed | |
618 | * algorithm it supports. | |
619 | */ | |
620 | void sctp_auth_asoc_set_default_hmac(struct sctp_association *asoc, | |
621 | struct sctp_hmac_algo_param *hmacs) | |
622 | { | |
623 | struct sctp_endpoint *ep; | |
624 | __u16 id; | |
625 | int i; | |
626 | int n_params; | |
627 | ||
628 | /* if the default id is already set, use it */ | |
629 | if (asoc->default_hmac_id) | |
630 | return; | |
631 | ||
3c918704 XL |
632 | n_params = (ntohs(hmacs->param_hdr.length) - |
633 | sizeof(struct sctp_paramhdr)) >> 1; | |
1f485649 VY |
634 | ep = asoc->ep; |
635 | for (i = 0; i < n_params; i++) { | |
636 | id = ntohs(hmacs->hmac_ids[i]); | |
637 | ||
638 | /* Check the id is in the supported range */ | |
639 | if (id > SCTP_AUTH_HMAC_ID_MAX) | |
640 | continue; | |
641 | ||
642 | /* If this TFM has been allocated, use this id */ | |
643 | if (ep->auth_hmacs[id]) { | |
644 | asoc->default_hmac_id = id; | |
645 | break; | |
646 | } | |
647 | } | |
648 | } | |
649 | ||
650 | ||
651 | /* Check to see if the given chunk is supposed to be authenticated */ | |
6d85e68f | 652 | static int __sctp_auth_cid(enum sctp_cid chunk, struct sctp_chunks_param *param) |
1f485649 VY |
653 | { |
654 | unsigned short len; | |
655 | int found = 0; | |
656 | int i; | |
657 | ||
555d3d5d | 658 | if (!param || param->param_hdr.length == 0) |
1f485649 VY |
659 | return 0; |
660 | ||
3c918704 | 661 | len = ntohs(param->param_hdr.length) - sizeof(struct sctp_paramhdr); |
1f485649 VY |
662 | |
663 | /* SCTP-AUTH, Section 3.2 | |
664 | * The chunk types for INIT, INIT-ACK, SHUTDOWN-COMPLETE and AUTH | |
665 | * chunks MUST NOT be listed in the CHUNKS parameter. However, if | |
666 | * a CHUNKS parameter is received then the types for INIT, INIT-ACK, | |
667 | * SHUTDOWN-COMPLETE and AUTH chunks MUST be ignored. | |
668 | */ | |
669 | for (i = 0; !found && i < len; i++) { | |
670 | switch (param->chunks[i]) { | |
f7010e61 | 671 | case SCTP_CID_INIT: |
672 | case SCTP_CID_INIT_ACK: | |
673 | case SCTP_CID_SHUTDOWN_COMPLETE: | |
674 | case SCTP_CID_AUTH: | |
1f485649 VY |
675 | break; |
676 | ||
f7010e61 | 677 | default: |
1f485649 | 678 | if (param->chunks[i] == chunk) |
f7010e61 | 679 | found = 1; |
1f485649 VY |
680 | break; |
681 | } | |
682 | } | |
683 | ||
684 | return found; | |
685 | } | |
686 | ||
687 | /* Check if peer requested that this chunk is authenticated */ | |
6d85e68f | 688 | int sctp_auth_send_cid(enum sctp_cid chunk, const struct sctp_association *asoc) |
1f485649 | 689 | { |
e1fc3b14 EB |
690 | if (!asoc) |
691 | return 0; | |
692 | ||
b14878cc | 693 | if (!asoc->ep->auth_enable || !asoc->peer.auth_capable) |
1f485649 VY |
694 | return 0; |
695 | ||
696 | return __sctp_auth_cid(chunk, asoc->peer.peer_chunks); | |
697 | } | |
698 | ||
699 | /* Check if we requested that peer authenticate this chunk. */ | |
6d85e68f | 700 | int sctp_auth_recv_cid(enum sctp_cid chunk, const struct sctp_association *asoc) |
1f485649 | 701 | { |
e1fc3b14 EB |
702 | if (!asoc) |
703 | return 0; | |
704 | ||
b14878cc | 705 | if (!asoc->ep->auth_enable) |
1f485649 VY |
706 | return 0; |
707 | ||
708 | return __sctp_auth_cid(chunk, | |
709 | (struct sctp_chunks_param *)asoc->c.auth_chunks); | |
710 | } | |
711 | ||
712 | /* SCTP-AUTH: Section 6.2: | |
713 | * The sender MUST calculate the MAC as described in RFC2104 [2] using | |
714 | * the hash function H as described by the MAC Identifier and the shared | |
715 | * association key K based on the endpoint pair shared key described by | |
716 | * the shared key identifier. The 'data' used for the computation of | |
717 | * the AUTH-chunk is given by the AUTH chunk with its HMAC field set to | |
718 | * zero (as shown in Figure 6) followed by all chunks that are placed | |
719 | * after the AUTH chunk in the SCTP packet. | |
720 | */ | |
721 | void sctp_auth_calculate_hmac(const struct sctp_association *asoc, | |
1b1e0bc9 XL |
722 | struct sk_buff *skb, struct sctp_auth_chunk *auth, |
723 | struct sctp_shared_key *ep_key, gfp_t gfp) | |
1f485649 | 724 | { |
1f485649 | 725 | struct sctp_auth_bytes *asoc_key; |
1b1e0bc9 | 726 | struct crypto_shash *tfm; |
1f485649 | 727 | __u16 key_id, hmac_id; |
1f485649 VY |
728 | unsigned char *end; |
729 | int free_key = 0; | |
1b1e0bc9 | 730 | __u8 *digest; |
1f485649 VY |
731 | |
732 | /* Extract the info we need: | |
733 | * - hmac id | |
734 | * - key id | |
735 | */ | |
736 | key_id = ntohs(auth->auth_hdr.shkey_id); | |
737 | hmac_id = ntohs(auth->auth_hdr.hmac_id); | |
738 | ||
739 | if (key_id == asoc->active_key_id) | |
740 | asoc_key = asoc->asoc_shared_key; | |
741 | else { | |
1b1e0bc9 | 742 | /* ep_key can't be NULL here */ |
1f485649 VY |
743 | asoc_key = sctp_auth_asoc_create_secret(asoc, ep_key, gfp); |
744 | if (!asoc_key) | |
745 | return; | |
746 | ||
747 | free_key = 1; | |
748 | } | |
749 | ||
750 | /* set up scatter list */ | |
751 | end = skb_tail_pointer(skb); | |
1f485649 | 752 | |
5821c769 | 753 | tfm = asoc->ep->auth_hmacs[hmac_id]; |
1f485649 VY |
754 | |
755 | digest = auth->auth_hdr.hmac; | |
5821c769 | 756 | if (crypto_shash_setkey(tfm, &asoc_key->data[0], asoc_key->len)) |
1f485649 VY |
757 | goto free; |
758 | ||
5821c769 HX |
759 | { |
760 | SHASH_DESC_ON_STACK(desc, tfm); | |
761 | ||
762 | desc->tfm = tfm; | |
5821c769 HX |
763 | crypto_shash_digest(desc, (u8 *)auth, |
764 | end - (unsigned char *)auth, digest); | |
765 | shash_desc_zero(desc); | |
766 | } | |
1f485649 VY |
767 | |
768 | free: | |
769 | if (free_key) | |
770 | sctp_auth_key_put(asoc_key); | |
771 | } | |
65b07e5d VY |
772 | |
773 | /* API Helpers */ | |
774 | ||
775 | /* Add a chunk to the endpoint authenticated chunk list */ | |
776 | int sctp_auth_ep_add_chunkid(struct sctp_endpoint *ep, __u8 chunk_id) | |
777 | { | |
778 | struct sctp_chunks_param *p = ep->auth_chunk_list; | |
779 | __u16 nchunks; | |
780 | __u16 param_len; | |
781 | ||
782 | /* If this chunk is already specified, we are done */ | |
783 | if (__sctp_auth_cid(chunk_id, p)) | |
784 | return 0; | |
785 | ||
786 | /* Check if we can add this chunk to the array */ | |
787 | param_len = ntohs(p->param_hdr.length); | |
3c918704 | 788 | nchunks = param_len - sizeof(struct sctp_paramhdr); |
65b07e5d VY |
789 | if (nchunks == SCTP_NUM_CHUNK_TYPES) |
790 | return -EINVAL; | |
791 | ||
792 | p->chunks[nchunks] = chunk_id; | |
793 | p->param_hdr.length = htons(param_len + 1); | |
794 | return 0; | |
795 | } | |
796 | ||
797 | /* Add hmac identifires to the endpoint list of supported hmac ids */ | |
798 | int sctp_auth_ep_set_hmacs(struct sctp_endpoint *ep, | |
799 | struct sctp_hmacalgo *hmacs) | |
800 | { | |
801 | int has_sha1 = 0; | |
802 | __u16 id; | |
803 | int i; | |
804 | ||
805 | /* Scan the list looking for unsupported id. Also make sure that | |
806 | * SHA1 is specified. | |
807 | */ | |
808 | for (i = 0; i < hmacs->shmac_num_idents; i++) { | |
809 | id = hmacs->shmac_idents[i]; | |
810 | ||
d9724055 VY |
811 | if (id > SCTP_AUTH_HMAC_ID_MAX) |
812 | return -EOPNOTSUPP; | |
813 | ||
65b07e5d VY |
814 | if (SCTP_AUTH_HMAC_ID_SHA1 == id) |
815 | has_sha1 = 1; | |
816 | ||
817 | if (!sctp_hmac_list[id].hmac_name) | |
818 | return -EOPNOTSUPP; | |
819 | } | |
820 | ||
821 | if (!has_sha1) | |
822 | return -EINVAL; | |
823 | ||
ed5a377d | 824 | for (i = 0; i < hmacs->shmac_num_idents; i++) |
3c918704 XL |
825 | ep->auth_hmacs_list->hmac_ids[i] = |
826 | htons(hmacs->shmac_idents[i]); | |
827 | ep->auth_hmacs_list->param_hdr.length = | |
828 | htons(sizeof(struct sctp_paramhdr) + | |
829 | hmacs->shmac_num_idents * sizeof(__u16)); | |
65b07e5d VY |
830 | return 0; |
831 | } | |
832 | ||
833 | /* Set a new shared key on either endpoint or association. If the | |
834 | * the key with a same ID already exists, replace the key (remove the | |
835 | * old key and add a new one). | |
836 | */ | |
837 | int sctp_auth_set_key(struct sctp_endpoint *ep, | |
838 | struct sctp_association *asoc, | |
839 | struct sctp_authkey *auth_key) | |
840 | { | |
1b1e0bc9 | 841 | struct sctp_shared_key *cur_key, *shkey; |
65b07e5d VY |
842 | struct sctp_auth_bytes *key; |
843 | struct list_head *sh_keys; | |
844 | int replace = 0; | |
845 | ||
846 | /* Try to find the given key id to see if | |
847 | * we are doing a replace, or adding a new key | |
848 | */ | |
849 | if (asoc) | |
850 | sh_keys = &asoc->endpoint_shared_keys; | |
851 | else | |
852 | sh_keys = &ep->endpoint_shared_keys; | |
853 | ||
1b1e0bc9 XL |
854 | key_for_each(shkey, sh_keys) { |
855 | if (shkey->key_id == auth_key->sca_keynumber) { | |
65b07e5d VY |
856 | replace = 1; |
857 | break; | |
858 | } | |
859 | } | |
860 | ||
1b1e0bc9 XL |
861 | cur_key = sctp_auth_shkey_create(auth_key->sca_keynumber, GFP_KERNEL); |
862 | if (!cur_key) | |
863 | return -ENOMEM; | |
65b07e5d VY |
864 | |
865 | /* Create a new key data based on the info passed in */ | |
7e8616d8 | 866 | key = sctp_auth_create_key(auth_key->sca_keylength, GFP_KERNEL); |
1b1e0bc9 XL |
867 | if (!key) { |
868 | kfree(cur_key); | |
869 | return -ENOMEM; | |
870 | } | |
65b07e5d | 871 | |
7e8616d8 | 872 | memcpy(key->data, &auth_key->sca_key[0], auth_key->sca_keylength); |
1b1e0bc9 | 873 | cur_key->key = key; |
65b07e5d | 874 | |
1b1e0bc9 XL |
875 | if (replace) { |
876 | list_del_init(&shkey->key_list); | |
877 | sctp_auth_shkey_release(shkey); | |
878 | } | |
879 | list_add(&cur_key->key_list, sh_keys); | |
65b07e5d | 880 | |
65b07e5d | 881 | return 0; |
65b07e5d VY |
882 | } |
883 | ||
884 | int 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 | ||
601590ec | 905 | if (!found || key->deactivated) |
65b07e5d VY |
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 | ||
917 | int 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); | |
1b1e0bc9 | 952 | sctp_auth_shkey_release(key); |
65b07e5d VY |
953 | |
954 | return 0; | |
955 | } | |
601590ec XL |
956 | |
957 | int sctp_auth_deact_key_id(struct sctp_endpoint *ep, | |
958 | struct sctp_association *asoc, __u16 key_id) | |
959 | { | |
960 | struct sctp_shared_key *key; | |
961 | struct list_head *sh_keys; | |
962 | int found = 0; | |
963 | ||
964 | /* The key identifier MUST NOT be the current active key | |
965 | * The key identifier MUST correst to an existing key | |
966 | */ | |
967 | if (asoc) { | |
968 | if (asoc->active_key_id == key_id) | |
969 | return -EINVAL; | |
970 | ||
971 | sh_keys = &asoc->endpoint_shared_keys; | |
972 | } else { | |
973 | if (ep->active_key_id == key_id) | |
974 | return -EINVAL; | |
975 | ||
976 | sh_keys = &ep->endpoint_shared_keys; | |
977 | } | |
978 | ||
979 | key_for_each(key, sh_keys) { | |
980 | if (key->key_id == key_id) { | |
981 | found = 1; | |
982 | break; | |
983 | } | |
984 | } | |
985 | ||
986 | if (!found) | |
987 | return -EINVAL; | |
988 | ||
ec2e506c XL |
989 | /* refcnt == 1 and !list_empty mean it's not being used anywhere |
990 | * and deactivated will be set, so it's time to notify userland | |
991 | * that this shkey can be freed. | |
992 | */ | |
993 | if (asoc && !list_empty(&key->key_list) && | |
994 | refcount_read(&key->refcnt) == 1) { | |
995 | struct sctp_ulpevent *ev; | |
996 | ||
997 | ev = sctp_ulpevent_make_authkey(asoc, key->key_id, | |
998 | SCTP_AUTH_FREE_KEY, GFP_KERNEL); | |
999 | if (ev) | |
1000 | asoc->stream.si->enqueue_event(&asoc->ulpq, ev); | |
1001 | } | |
1002 | ||
601590ec XL |
1003 | key->deactivated = 1; |
1004 | ||
1005 | return 0; | |
1006 | } |