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5d637d5a PB |
1 | /* |
2 | * Copyright (C) 2014 Fraunhofer ITWM | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 | |
6 | * as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | * GNU General Public License for more details. | |
12 | * | |
13 | * Written by: | |
14 | * Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de> | |
15 | */ | |
16 | ||
17 | #include <linux/err.h> | |
18 | #include <linux/bug.h> | |
19 | #include <linux/completion.h> | |
4ca24aca | 20 | #include <linux/ieee802154.h> |
4c14a2fb | 21 | #include <crypto/algapi.h> |
5d637d5a | 22 | |
0f1556bc | 23 | #include "ieee802154_i.h" |
5d637d5a PB |
24 | #include "llsec.h" |
25 | ||
26 | static void llsec_key_put(struct mac802154_llsec_key *key); | |
27 | static bool llsec_key_id_equal(const struct ieee802154_llsec_key_id *a, | |
28 | const struct ieee802154_llsec_key_id *b); | |
29 | ||
30 | static void llsec_dev_free(struct mac802154_llsec_device *dev); | |
31 | ||
32 | void mac802154_llsec_init(struct mac802154_llsec *sec) | |
33 | { | |
34 | memset(sec, 0, sizeof(*sec)); | |
35 | ||
36 | memset(&sec->params.default_key_source, 0xFF, IEEE802154_ADDR_LEN); | |
37 | ||
38 | INIT_LIST_HEAD(&sec->table.security_levels); | |
39 | INIT_LIST_HEAD(&sec->table.devices); | |
40 | INIT_LIST_HEAD(&sec->table.keys); | |
41 | hash_init(sec->devices_short); | |
42 | hash_init(sec->devices_hw); | |
43 | rwlock_init(&sec->lock); | |
44 | } | |
45 | ||
46 | void mac802154_llsec_destroy(struct mac802154_llsec *sec) | |
47 | { | |
48 | struct ieee802154_llsec_seclevel *sl, *sn; | |
49 | struct ieee802154_llsec_device *dev, *dn; | |
50 | struct ieee802154_llsec_key_entry *key, *kn; | |
51 | ||
52 | list_for_each_entry_safe(sl, sn, &sec->table.security_levels, list) { | |
53 | struct mac802154_llsec_seclevel *msl; | |
54 | ||
55 | msl = container_of(sl, struct mac802154_llsec_seclevel, level); | |
56 | list_del(&sl->list); | |
57 | kfree(msl); | |
58 | } | |
59 | ||
60 | list_for_each_entry_safe(dev, dn, &sec->table.devices, list) { | |
61 | struct mac802154_llsec_device *mdev; | |
62 | ||
63 | mdev = container_of(dev, struct mac802154_llsec_device, dev); | |
64 | list_del(&dev->list); | |
65 | llsec_dev_free(mdev); | |
66 | } | |
67 | ||
68 | list_for_each_entry_safe(key, kn, &sec->table.keys, list) { | |
69 | struct mac802154_llsec_key *mkey; | |
70 | ||
71 | mkey = container_of(key->key, struct mac802154_llsec_key, key); | |
72 | list_del(&key->list); | |
73 | llsec_key_put(mkey); | |
74 | kfree(key); | |
75 | } | |
76 | } | |
77 | ||
5d637d5a PB |
78 | int mac802154_llsec_get_params(struct mac802154_llsec *sec, |
79 | struct ieee802154_llsec_params *params) | |
80 | { | |
81 | read_lock_bh(&sec->lock); | |
82 | *params = sec->params; | |
83 | read_unlock_bh(&sec->lock); | |
84 | ||
85 | return 0; | |
86 | } | |
87 | ||
88 | int mac802154_llsec_set_params(struct mac802154_llsec *sec, | |
89 | const struct ieee802154_llsec_params *params, | |
90 | int changed) | |
91 | { | |
92 | write_lock_bh(&sec->lock); | |
93 | ||
94 | if (changed & IEEE802154_LLSEC_PARAM_ENABLED) | |
95 | sec->params.enabled = params->enabled; | |
96 | if (changed & IEEE802154_LLSEC_PARAM_FRAME_COUNTER) | |
97 | sec->params.frame_counter = params->frame_counter; | |
98 | if (changed & IEEE802154_LLSEC_PARAM_OUT_LEVEL) | |
99 | sec->params.out_level = params->out_level; | |
100 | if (changed & IEEE802154_LLSEC_PARAM_OUT_KEY) | |
101 | sec->params.out_key = params->out_key; | |
102 | if (changed & IEEE802154_LLSEC_PARAM_KEY_SOURCE) | |
103 | sec->params.default_key_source = params->default_key_source; | |
104 | if (changed & IEEE802154_LLSEC_PARAM_PAN_ID) | |
105 | sec->params.pan_id = params->pan_id; | |
106 | if (changed & IEEE802154_LLSEC_PARAM_HWADDR) | |
107 | sec->params.hwaddr = params->hwaddr; | |
108 | if (changed & IEEE802154_LLSEC_PARAM_COORD_HWADDR) | |
109 | sec->params.coord_hwaddr = params->coord_hwaddr; | |
110 | if (changed & IEEE802154_LLSEC_PARAM_COORD_SHORTADDR) | |
111 | sec->params.coord_shortaddr = params->coord_shortaddr; | |
112 | ||
113 | write_unlock_bh(&sec->lock); | |
114 | ||
115 | return 0; | |
116 | } | |
117 | ||
5d637d5a PB |
118 | static struct mac802154_llsec_key* |
119 | llsec_key_alloc(const struct ieee802154_llsec_key *template) | |
120 | { | |
121 | const int authsizes[3] = { 4, 8, 16 }; | |
122 | struct mac802154_llsec_key *key; | |
123 | int i; | |
124 | ||
125 | key = kzalloc(sizeof(*key), GFP_KERNEL); | |
126 | if (!key) | |
127 | return NULL; | |
128 | ||
129 | kref_init(&key->ref); | |
130 | key->key = *template; | |
131 | ||
132 | BUILD_BUG_ON(ARRAY_SIZE(authsizes) != ARRAY_SIZE(key->tfm)); | |
133 | ||
134 | for (i = 0; i < ARRAY_SIZE(key->tfm); i++) { | |
135 | key->tfm[i] = crypto_alloc_aead("ccm(aes)", 0, | |
136 | CRYPTO_ALG_ASYNC); | |
137 | if (!key->tfm[i]) | |
138 | goto err_tfm; | |
139 | if (crypto_aead_setkey(key->tfm[i], template->key, | |
140 | IEEE802154_LLSEC_KEY_SIZE)) | |
141 | goto err_tfm; | |
142 | if (crypto_aead_setauthsize(key->tfm[i], authsizes[i])) | |
143 | goto err_tfm; | |
144 | } | |
145 | ||
146 | key->tfm0 = crypto_alloc_blkcipher("ctr(aes)", 0, CRYPTO_ALG_ASYNC); | |
147 | if (!key->tfm0) | |
148 | goto err_tfm; | |
149 | ||
150 | if (crypto_blkcipher_setkey(key->tfm0, template->key, | |
151 | IEEE802154_LLSEC_KEY_SIZE)) | |
152 | goto err_tfm0; | |
153 | ||
154 | return key; | |
155 | ||
156 | err_tfm0: | |
157 | crypto_free_blkcipher(key->tfm0); | |
158 | err_tfm: | |
159 | for (i = 0; i < ARRAY_SIZE(key->tfm); i++) | |
160 | if (key->tfm[i]) | |
161 | crypto_free_aead(key->tfm[i]); | |
162 | ||
163 | kfree(key); | |
164 | return NULL; | |
165 | } | |
166 | ||
167 | static void llsec_key_release(struct kref *ref) | |
168 | { | |
169 | struct mac802154_llsec_key *key; | |
170 | int i; | |
171 | ||
172 | key = container_of(ref, struct mac802154_llsec_key, ref); | |
173 | ||
174 | for (i = 0; i < ARRAY_SIZE(key->tfm); i++) | |
175 | crypto_free_aead(key->tfm[i]); | |
176 | ||
177 | crypto_free_blkcipher(key->tfm0); | |
178 | kfree(key); | |
179 | } | |
180 | ||
181 | static struct mac802154_llsec_key* | |
182 | llsec_key_get(struct mac802154_llsec_key *key) | |
183 | { | |
184 | kref_get(&key->ref); | |
185 | return key; | |
186 | } | |
187 | ||
188 | static void llsec_key_put(struct mac802154_llsec_key *key) | |
189 | { | |
190 | kref_put(&key->ref, llsec_key_release); | |
191 | } | |
192 | ||
193 | static bool llsec_key_id_equal(const struct ieee802154_llsec_key_id *a, | |
194 | const struct ieee802154_llsec_key_id *b) | |
195 | { | |
196 | if (a->mode != b->mode) | |
197 | return false; | |
198 | ||
199 | if (a->mode == IEEE802154_SCF_KEY_IMPLICIT) | |
200 | return ieee802154_addr_equal(&a->device_addr, &b->device_addr); | |
201 | ||
202 | if (a->id != b->id) | |
203 | return false; | |
204 | ||
205 | switch (a->mode) { | |
53819a6c PB |
206 | case IEEE802154_SCF_KEY_INDEX: |
207 | return true; | |
5d637d5a PB |
208 | case IEEE802154_SCF_KEY_SHORT_INDEX: |
209 | return a->short_source == b->short_source; | |
210 | case IEEE802154_SCF_KEY_HW_INDEX: | |
211 | return a->extended_source == b->extended_source; | |
212 | } | |
213 | ||
214 | return false; | |
215 | } | |
216 | ||
217 | int mac802154_llsec_key_add(struct mac802154_llsec *sec, | |
218 | const struct ieee802154_llsec_key_id *id, | |
219 | const struct ieee802154_llsec_key *key) | |
220 | { | |
221 | struct mac802154_llsec_key *mkey = NULL; | |
222 | struct ieee802154_llsec_key_entry *pos, *new; | |
223 | ||
224 | if (!(key->frame_types & (1 << IEEE802154_FC_TYPE_MAC_CMD)) && | |
225 | key->cmd_frame_ids) | |
226 | return -EINVAL; | |
227 | ||
228 | list_for_each_entry(pos, &sec->table.keys, list) { | |
229 | if (llsec_key_id_equal(&pos->id, id)) | |
230 | return -EEXIST; | |
231 | ||
232 | if (memcmp(pos->key->key, key->key, | |
233 | IEEE802154_LLSEC_KEY_SIZE)) | |
234 | continue; | |
235 | ||
236 | mkey = container_of(pos->key, struct mac802154_llsec_key, key); | |
237 | ||
238 | /* Don't allow multiple instances of the same AES key to have | |
239 | * different allowed frame types/command frame ids, as this is | |
240 | * not possible in the 802.15.4 PIB. | |
241 | */ | |
242 | if (pos->key->frame_types != key->frame_types || | |
243 | pos->key->cmd_frame_ids != key->cmd_frame_ids) | |
244 | return -EEXIST; | |
245 | ||
246 | break; | |
247 | } | |
248 | ||
249 | new = kzalloc(sizeof(*new), GFP_KERNEL); | |
250 | if (!new) | |
251 | return -ENOMEM; | |
252 | ||
253 | if (!mkey) | |
254 | mkey = llsec_key_alloc(key); | |
255 | else | |
256 | mkey = llsec_key_get(mkey); | |
257 | ||
258 | if (!mkey) | |
259 | goto fail; | |
260 | ||
261 | new->id = *id; | |
262 | new->key = &mkey->key; | |
263 | ||
264 | list_add_rcu(&new->list, &sec->table.keys); | |
265 | ||
266 | return 0; | |
267 | ||
268 | fail: | |
269 | kfree(new); | |
270 | return -ENOMEM; | |
271 | } | |
272 | ||
273 | int mac802154_llsec_key_del(struct mac802154_llsec *sec, | |
274 | const struct ieee802154_llsec_key_id *key) | |
275 | { | |
276 | struct ieee802154_llsec_key_entry *pos; | |
277 | ||
278 | list_for_each_entry(pos, &sec->table.keys, list) { | |
279 | struct mac802154_llsec_key *mkey; | |
280 | ||
281 | mkey = container_of(pos->key, struct mac802154_llsec_key, key); | |
282 | ||
283 | if (llsec_key_id_equal(&pos->id, key)) { | |
fff1f59b | 284 | list_del_rcu(&pos->list); |
5d637d5a PB |
285 | llsec_key_put(mkey); |
286 | return 0; | |
287 | } | |
288 | } | |
289 | ||
290 | return -ENOENT; | |
291 | } | |
292 | ||
5d637d5a PB |
293 | static bool llsec_dev_use_shortaddr(__le16 short_addr) |
294 | { | |
295 | return short_addr != cpu_to_le16(IEEE802154_ADDR_UNDEF) && | |
296 | short_addr != cpu_to_le16(0xffff); | |
297 | } | |
298 | ||
299 | static u32 llsec_dev_hash_short(__le16 short_addr, __le16 pan_id) | |
300 | { | |
1db99604 | 301 | return ((__force u16)short_addr) << 16 | (__force u16)pan_id; |
5d637d5a PB |
302 | } |
303 | ||
304 | static u64 llsec_dev_hash_long(__le64 hwaddr) | |
305 | { | |
1db99604 | 306 | return (__force u64)hwaddr; |
5d637d5a PB |
307 | } |
308 | ||
309 | static struct mac802154_llsec_device* | |
310 | llsec_dev_find_short(struct mac802154_llsec *sec, __le16 short_addr, | |
311 | __le16 pan_id) | |
312 | { | |
313 | struct mac802154_llsec_device *dev; | |
314 | u32 key = llsec_dev_hash_short(short_addr, pan_id); | |
315 | ||
316 | hash_for_each_possible_rcu(sec->devices_short, dev, bucket_s, key) { | |
317 | if (dev->dev.short_addr == short_addr && | |
318 | dev->dev.pan_id == pan_id) | |
319 | return dev; | |
320 | } | |
321 | ||
322 | return NULL; | |
323 | } | |
324 | ||
325 | static struct mac802154_llsec_device* | |
326 | llsec_dev_find_long(struct mac802154_llsec *sec, __le64 hwaddr) | |
327 | { | |
328 | struct mac802154_llsec_device *dev; | |
329 | u64 key = llsec_dev_hash_long(hwaddr); | |
330 | ||
331 | hash_for_each_possible_rcu(sec->devices_hw, dev, bucket_hw, key) { | |
332 | if (dev->dev.hwaddr == hwaddr) | |
333 | return dev; | |
334 | } | |
335 | ||
336 | return NULL; | |
337 | } | |
338 | ||
339 | static void llsec_dev_free(struct mac802154_llsec_device *dev) | |
340 | { | |
341 | struct ieee802154_llsec_device_key *pos, *pn; | |
342 | struct mac802154_llsec_device_key *devkey; | |
343 | ||
344 | list_for_each_entry_safe(pos, pn, &dev->dev.keys, list) { | |
345 | devkey = container_of(pos, struct mac802154_llsec_device_key, | |
346 | devkey); | |
347 | ||
348 | list_del(&pos->list); | |
349 | kfree(devkey); | |
350 | } | |
351 | ||
352 | kfree(dev); | |
353 | } | |
354 | ||
355 | int mac802154_llsec_dev_add(struct mac802154_llsec *sec, | |
356 | const struct ieee802154_llsec_device *dev) | |
357 | { | |
358 | struct mac802154_llsec_device *entry; | |
359 | u32 skey = llsec_dev_hash_short(dev->short_addr, dev->pan_id); | |
360 | u64 hwkey = llsec_dev_hash_long(dev->hwaddr); | |
361 | ||
362 | BUILD_BUG_ON(sizeof(hwkey) != IEEE802154_ADDR_LEN); | |
363 | ||
364 | if ((llsec_dev_use_shortaddr(dev->short_addr) && | |
365 | llsec_dev_find_short(sec, dev->short_addr, dev->pan_id)) || | |
366 | llsec_dev_find_long(sec, dev->hwaddr)) | |
367 | return -EEXIST; | |
368 | ||
369 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
370 | if (!entry) | |
371 | return -ENOMEM; | |
372 | ||
373 | entry->dev = *dev; | |
374 | spin_lock_init(&entry->lock); | |
375 | INIT_LIST_HEAD(&entry->dev.keys); | |
376 | ||
377 | if (llsec_dev_use_shortaddr(dev->short_addr)) | |
378 | hash_add_rcu(sec->devices_short, &entry->bucket_s, skey); | |
379 | else | |
380 | INIT_HLIST_NODE(&entry->bucket_s); | |
381 | ||
382 | hash_add_rcu(sec->devices_hw, &entry->bucket_hw, hwkey); | |
383 | list_add_tail_rcu(&entry->dev.list, &sec->table.devices); | |
384 | ||
385 | return 0; | |
386 | } | |
387 | ||
388 | static void llsec_dev_free_rcu(struct rcu_head *rcu) | |
389 | { | |
390 | llsec_dev_free(container_of(rcu, struct mac802154_llsec_device, rcu)); | |
391 | } | |
392 | ||
393 | int mac802154_llsec_dev_del(struct mac802154_llsec *sec, __le64 device_addr) | |
394 | { | |
395 | struct mac802154_llsec_device *pos; | |
396 | ||
397 | pos = llsec_dev_find_long(sec, device_addr); | |
398 | if (!pos) | |
399 | return -ENOENT; | |
400 | ||
401 | hash_del_rcu(&pos->bucket_s); | |
402 | hash_del_rcu(&pos->bucket_hw); | |
403 | call_rcu(&pos->rcu, llsec_dev_free_rcu); | |
404 | ||
405 | return 0; | |
406 | } | |
407 | ||
5d637d5a PB |
408 | static struct mac802154_llsec_device_key* |
409 | llsec_devkey_find(struct mac802154_llsec_device *dev, | |
410 | const struct ieee802154_llsec_key_id *key) | |
411 | { | |
412 | struct ieee802154_llsec_device_key *devkey; | |
413 | ||
414 | list_for_each_entry_rcu(devkey, &dev->dev.keys, list) { | |
415 | if (!llsec_key_id_equal(key, &devkey->key_id)) | |
416 | continue; | |
417 | ||
418 | return container_of(devkey, struct mac802154_llsec_device_key, | |
419 | devkey); | |
420 | } | |
421 | ||
422 | return NULL; | |
423 | } | |
424 | ||
425 | int mac802154_llsec_devkey_add(struct mac802154_llsec *sec, | |
426 | __le64 dev_addr, | |
427 | const struct ieee802154_llsec_device_key *key) | |
428 | { | |
429 | struct mac802154_llsec_device *dev; | |
430 | struct mac802154_llsec_device_key *devkey; | |
431 | ||
432 | dev = llsec_dev_find_long(sec, dev_addr); | |
433 | ||
434 | if (!dev) | |
435 | return -ENOENT; | |
436 | ||
437 | if (llsec_devkey_find(dev, &key->key_id)) | |
438 | return -EEXIST; | |
439 | ||
440 | devkey = kmalloc(sizeof(*devkey), GFP_KERNEL); | |
441 | if (!devkey) | |
442 | return -ENOMEM; | |
443 | ||
444 | devkey->devkey = *key; | |
445 | list_add_tail_rcu(&devkey->devkey.list, &dev->dev.keys); | |
446 | return 0; | |
447 | } | |
448 | ||
449 | int mac802154_llsec_devkey_del(struct mac802154_llsec *sec, | |
450 | __le64 dev_addr, | |
451 | const struct ieee802154_llsec_device_key *key) | |
452 | { | |
453 | struct mac802154_llsec_device *dev; | |
454 | struct mac802154_llsec_device_key *devkey; | |
455 | ||
456 | dev = llsec_dev_find_long(sec, dev_addr); | |
457 | ||
458 | if (!dev) | |
459 | return -ENOENT; | |
460 | ||
461 | devkey = llsec_devkey_find(dev, &key->key_id); | |
462 | if (!devkey) | |
463 | return -ENOENT; | |
464 | ||
465 | list_del_rcu(&devkey->devkey.list); | |
466 | kfree_rcu(devkey, rcu); | |
467 | return 0; | |
468 | } | |
469 | ||
5d637d5a PB |
470 | static struct mac802154_llsec_seclevel* |
471 | llsec_find_seclevel(const struct mac802154_llsec *sec, | |
472 | const struct ieee802154_llsec_seclevel *sl) | |
473 | { | |
474 | struct ieee802154_llsec_seclevel *pos; | |
475 | ||
476 | list_for_each_entry(pos, &sec->table.security_levels, list) { | |
477 | if (pos->frame_type != sl->frame_type || | |
478 | (pos->frame_type == IEEE802154_FC_TYPE_MAC_CMD && | |
479 | pos->cmd_frame_id != sl->cmd_frame_id) || | |
480 | pos->device_override != sl->device_override || | |
481 | pos->sec_levels != sl->sec_levels) | |
482 | continue; | |
483 | ||
484 | return container_of(pos, struct mac802154_llsec_seclevel, | |
485 | level); | |
486 | } | |
487 | ||
488 | return NULL; | |
489 | } | |
490 | ||
491 | int mac802154_llsec_seclevel_add(struct mac802154_llsec *sec, | |
492 | const struct ieee802154_llsec_seclevel *sl) | |
493 | { | |
494 | struct mac802154_llsec_seclevel *entry; | |
495 | ||
496 | if (llsec_find_seclevel(sec, sl)) | |
497 | return -EEXIST; | |
498 | ||
499 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
500 | if (!entry) | |
501 | return -ENOMEM; | |
502 | ||
503 | entry->level = *sl; | |
504 | ||
505 | list_add_tail_rcu(&entry->level.list, &sec->table.security_levels); | |
506 | ||
507 | return 0; | |
508 | } | |
509 | ||
510 | int mac802154_llsec_seclevel_del(struct mac802154_llsec *sec, | |
511 | const struct ieee802154_llsec_seclevel *sl) | |
512 | { | |
513 | struct mac802154_llsec_seclevel *pos; | |
514 | ||
515 | pos = llsec_find_seclevel(sec, sl); | |
516 | if (!pos) | |
517 | return -ENOENT; | |
518 | ||
519 | list_del_rcu(&pos->level.list); | |
520 | kfree_rcu(pos, rcu); | |
521 | ||
522 | return 0; | |
523 | } | |
03556e4d | 524 | |
03556e4d PB |
525 | static int llsec_recover_addr(struct mac802154_llsec *sec, |
526 | struct ieee802154_addr *addr) | |
527 | { | |
528 | __le16 caddr = sec->params.coord_shortaddr; | |
4710d806 | 529 | |
03556e4d PB |
530 | addr->pan_id = sec->params.pan_id; |
531 | ||
532 | if (caddr == cpu_to_le16(IEEE802154_ADDR_BROADCAST)) { | |
533 | return -EINVAL; | |
534 | } else if (caddr == cpu_to_le16(IEEE802154_ADDR_UNDEF)) { | |
535 | addr->extended_addr = sec->params.coord_hwaddr; | |
536 | addr->mode = IEEE802154_ADDR_LONG; | |
537 | } else { | |
538 | addr->short_addr = sec->params.coord_shortaddr; | |
539 | addr->mode = IEEE802154_ADDR_SHORT; | |
540 | } | |
541 | ||
542 | return 0; | |
543 | } | |
544 | ||
545 | static struct mac802154_llsec_key* | |
546 | llsec_lookup_key(struct mac802154_llsec *sec, | |
547 | const struct ieee802154_hdr *hdr, | |
548 | const struct ieee802154_addr *addr, | |
549 | struct ieee802154_llsec_key_id *key_id) | |
550 | { | |
551 | struct ieee802154_addr devaddr = *addr; | |
552 | u8 key_id_mode = hdr->sec.key_id_mode; | |
553 | struct ieee802154_llsec_key_entry *key_entry; | |
554 | struct mac802154_llsec_key *key; | |
555 | ||
556 | if (key_id_mode == IEEE802154_SCF_KEY_IMPLICIT && | |
557 | devaddr.mode == IEEE802154_ADDR_NONE) { | |
558 | if (hdr->fc.type == IEEE802154_FC_TYPE_BEACON) { | |
559 | devaddr.extended_addr = sec->params.coord_hwaddr; | |
560 | devaddr.mode = IEEE802154_ADDR_LONG; | |
561 | } else if (llsec_recover_addr(sec, &devaddr) < 0) { | |
562 | return NULL; | |
563 | } | |
564 | } | |
565 | ||
566 | list_for_each_entry_rcu(key_entry, &sec->table.keys, list) { | |
567 | const struct ieee802154_llsec_key_id *id = &key_entry->id; | |
568 | ||
569 | if (!(key_entry->key->frame_types & BIT(hdr->fc.type))) | |
570 | continue; | |
571 | ||
572 | if (id->mode != key_id_mode) | |
573 | continue; | |
574 | ||
575 | if (key_id_mode == IEEE802154_SCF_KEY_IMPLICIT) { | |
576 | if (ieee802154_addr_equal(&devaddr, &id->device_addr)) | |
577 | goto found; | |
578 | } else { | |
579 | if (id->id != hdr->sec.key_id) | |
580 | continue; | |
581 | ||
582 | if ((key_id_mode == IEEE802154_SCF_KEY_INDEX) || | |
583 | (key_id_mode == IEEE802154_SCF_KEY_SHORT_INDEX && | |
584 | id->short_source == hdr->sec.short_src) || | |
585 | (key_id_mode == IEEE802154_SCF_KEY_HW_INDEX && | |
586 | id->extended_source == hdr->sec.extended_src)) | |
587 | goto found; | |
588 | } | |
589 | } | |
590 | ||
591 | return NULL; | |
592 | ||
593 | found: | |
594 | key = container_of(key_entry->key, struct mac802154_llsec_key, key); | |
595 | if (key_id) | |
596 | *key_id = key_entry->id; | |
597 | return llsec_key_get(key); | |
598 | } | |
599 | ||
03556e4d PB |
600 | static void llsec_geniv(u8 iv[16], __le64 addr, |
601 | const struct ieee802154_sechdr *sec) | |
602 | { | |
603 | __be64 addr_bytes = (__force __be64) swab64((__force u64) addr); | |
604 | __be32 frame_counter = (__force __be32) swab32((__force u32) sec->frame_counter); | |
605 | ||
606 | iv[0] = 1; /* L' = L - 1 = 1 */ | |
607 | memcpy(iv + 1, &addr_bytes, sizeof(addr_bytes)); | |
608 | memcpy(iv + 9, &frame_counter, sizeof(frame_counter)); | |
609 | iv[13] = sec->level; | |
610 | iv[14] = 0; | |
611 | iv[15] = 1; | |
612 | } | |
613 | ||
614 | static int | |
615 | llsec_do_encrypt_unauth(struct sk_buff *skb, const struct mac802154_llsec *sec, | |
616 | const struct ieee802154_hdr *hdr, | |
617 | struct mac802154_llsec_key *key) | |
618 | { | |
619 | u8 iv[16]; | |
620 | struct scatterlist src; | |
621 | struct blkcipher_desc req = { | |
622 | .tfm = key->tfm0, | |
623 | .info = iv, | |
624 | .flags = 0, | |
625 | }; | |
626 | ||
627 | llsec_geniv(iv, sec->params.hwaddr, &hdr->sec); | |
628 | sg_init_one(&src, skb->data, skb->len); | |
629 | return crypto_blkcipher_encrypt_iv(&req, &src, &src, skb->len); | |
630 | } | |
631 | ||
632 | static struct crypto_aead* | |
633 | llsec_tfm_by_len(struct mac802154_llsec_key *key, int authlen) | |
634 | { | |
635 | int i; | |
636 | ||
637 | for (i = 0; i < ARRAY_SIZE(key->tfm); i++) | |
638 | if (crypto_aead_authsize(key->tfm[i]) == authlen) | |
639 | return key->tfm[i]; | |
640 | ||
641 | BUG(); | |
642 | } | |
643 | ||
644 | static int | |
645 | llsec_do_encrypt_auth(struct sk_buff *skb, const struct mac802154_llsec *sec, | |
646 | const struct ieee802154_hdr *hdr, | |
647 | struct mac802154_llsec_key *key) | |
648 | { | |
649 | u8 iv[16]; | |
650 | unsigned char *data; | |
651 | int authlen, assoclen, datalen, rc; | |
652 | struct scatterlist src, assoc[2], dst[2]; | |
653 | struct aead_request *req; | |
654 | ||
655 | authlen = ieee802154_sechdr_authtag_len(&hdr->sec); | |
656 | llsec_geniv(iv, sec->params.hwaddr, &hdr->sec); | |
657 | ||
658 | req = aead_request_alloc(llsec_tfm_by_len(key, authlen), GFP_ATOMIC); | |
659 | if (!req) | |
660 | return -ENOMEM; | |
661 | ||
662 | sg_init_table(assoc, 2); | |
663 | sg_set_buf(&assoc[0], skb_mac_header(skb), skb->mac_len); | |
664 | assoclen = skb->mac_len; | |
665 | ||
666 | data = skb_mac_header(skb) + skb->mac_len; | |
667 | datalen = skb_tail_pointer(skb) - data; | |
668 | ||
669 | if (hdr->sec.level & IEEE802154_SCF_SECLEVEL_ENC) { | |
670 | sg_set_buf(&assoc[1], data, 0); | |
671 | } else { | |
672 | sg_set_buf(&assoc[1], data, datalen); | |
673 | assoclen += datalen; | |
674 | datalen = 0; | |
675 | } | |
676 | ||
677 | sg_init_one(&src, data, datalen); | |
678 | ||
679 | sg_init_table(dst, 2); | |
680 | sg_set_buf(&dst[0], data, datalen); | |
681 | sg_set_buf(&dst[1], skb_put(skb, authlen), authlen); | |
682 | ||
683 | aead_request_set_callback(req, 0, NULL, NULL); | |
684 | aead_request_set_assoc(req, assoc, assoclen); | |
685 | aead_request_set_crypt(req, &src, dst, datalen, iv); | |
686 | ||
687 | rc = crypto_aead_encrypt(req); | |
688 | ||
689 | kfree(req); | |
690 | ||
691 | return rc; | |
692 | } | |
693 | ||
694 | static int llsec_do_encrypt(struct sk_buff *skb, | |
695 | const struct mac802154_llsec *sec, | |
696 | const struct ieee802154_hdr *hdr, | |
697 | struct mac802154_llsec_key *key) | |
698 | { | |
699 | if (hdr->sec.level == IEEE802154_SCF_SECLEVEL_ENC) | |
700 | return llsec_do_encrypt_unauth(skb, sec, hdr, key); | |
701 | else | |
702 | return llsec_do_encrypt_auth(skb, sec, hdr, key); | |
703 | } | |
704 | ||
705 | int mac802154_llsec_encrypt(struct mac802154_llsec *sec, struct sk_buff *skb) | |
706 | { | |
707 | struct ieee802154_hdr hdr; | |
708 | int rc, authlen, hlen; | |
709 | struct mac802154_llsec_key *key; | |
710 | u32 frame_ctr; | |
711 | ||
712 | hlen = ieee802154_hdr_pull(skb, &hdr); | |
713 | ||
714 | if (hlen < 0 || hdr.fc.type != IEEE802154_FC_TYPE_DATA) | |
715 | return -EINVAL; | |
716 | ||
717 | if (!hdr.fc.security_enabled || hdr.sec.level == 0) { | |
718 | skb_push(skb, hlen); | |
719 | return 0; | |
720 | } | |
721 | ||
722 | authlen = ieee802154_sechdr_authtag_len(&hdr.sec); | |
723 | ||
724 | if (skb->len + hlen + authlen + IEEE802154_MFR_SIZE > IEEE802154_MTU) | |
725 | return -EMSGSIZE; | |
726 | ||
727 | rcu_read_lock(); | |
728 | ||
729 | read_lock_bh(&sec->lock); | |
730 | ||
731 | if (!sec->params.enabled) { | |
732 | rc = -EINVAL; | |
733 | goto fail_read; | |
734 | } | |
735 | ||
736 | key = llsec_lookup_key(sec, &hdr, &hdr.dest, NULL); | |
737 | if (!key) { | |
738 | rc = -ENOKEY; | |
739 | goto fail_read; | |
740 | } | |
741 | ||
742 | read_unlock_bh(&sec->lock); | |
743 | ||
744 | write_lock_bh(&sec->lock); | |
745 | ||
746 | frame_ctr = be32_to_cpu(sec->params.frame_counter); | |
747 | hdr.sec.frame_counter = cpu_to_le32(frame_ctr); | |
748 | if (frame_ctr == 0xFFFFFFFF) { | |
749 | write_unlock_bh(&sec->lock); | |
750 | llsec_key_put(key); | |
751 | rc = -EOVERFLOW; | |
752 | goto fail; | |
753 | } | |
754 | ||
755 | sec->params.frame_counter = cpu_to_be32(frame_ctr + 1); | |
756 | ||
757 | write_unlock_bh(&sec->lock); | |
758 | ||
759 | rcu_read_unlock(); | |
760 | ||
761 | skb->mac_len = ieee802154_hdr_push(skb, &hdr); | |
762 | skb_reset_mac_header(skb); | |
763 | ||
764 | rc = llsec_do_encrypt(skb, sec, &hdr, key); | |
765 | llsec_key_put(key); | |
766 | ||
62e9c117 | 767 | return rc; |
03556e4d PB |
768 | |
769 | fail_read: | |
6f3eabcd | 770 | read_unlock_bh(&sec->lock); |
03556e4d PB |
771 | fail: |
772 | rcu_read_unlock(); | |
773 | return rc; | |
774 | } | |
4c14a2fb | 775 | |
4c14a2fb PB |
776 | static struct mac802154_llsec_device* |
777 | llsec_lookup_dev(struct mac802154_llsec *sec, | |
778 | const struct ieee802154_addr *addr) | |
779 | { | |
780 | struct ieee802154_addr devaddr = *addr; | |
781 | struct mac802154_llsec_device *dev = NULL; | |
782 | ||
783 | if (devaddr.mode == IEEE802154_ADDR_NONE && | |
784 | llsec_recover_addr(sec, &devaddr) < 0) | |
785 | return NULL; | |
786 | ||
787 | if (devaddr.mode == IEEE802154_ADDR_SHORT) { | |
788 | u32 key = llsec_dev_hash_short(devaddr.short_addr, | |
789 | devaddr.pan_id); | |
790 | ||
791 | hash_for_each_possible_rcu(sec->devices_short, dev, | |
792 | bucket_s, key) { | |
793 | if (dev->dev.pan_id == devaddr.pan_id && | |
794 | dev->dev.short_addr == devaddr.short_addr) | |
795 | return dev; | |
796 | } | |
797 | } else { | |
798 | u64 key = llsec_dev_hash_long(devaddr.extended_addr); | |
799 | ||
800 | hash_for_each_possible_rcu(sec->devices_hw, dev, | |
801 | bucket_hw, key) { | |
802 | if (dev->dev.hwaddr == devaddr.extended_addr) | |
803 | return dev; | |
804 | } | |
805 | } | |
806 | ||
807 | return NULL; | |
808 | } | |
809 | ||
810 | static int | |
811 | llsec_lookup_seclevel(const struct mac802154_llsec *sec, | |
812 | u8 frame_type, u8 cmd_frame_id, | |
813 | struct ieee802154_llsec_seclevel *rlevel) | |
814 | { | |
815 | struct ieee802154_llsec_seclevel *level; | |
816 | ||
817 | list_for_each_entry_rcu(level, &sec->table.security_levels, list) { | |
818 | if (level->frame_type == frame_type && | |
819 | (frame_type != IEEE802154_FC_TYPE_MAC_CMD || | |
820 | level->cmd_frame_id == cmd_frame_id)) { | |
821 | *rlevel = *level; | |
822 | return 0; | |
823 | } | |
824 | } | |
825 | ||
826 | return -EINVAL; | |
827 | } | |
828 | ||
829 | static int | |
830 | llsec_do_decrypt_unauth(struct sk_buff *skb, const struct mac802154_llsec *sec, | |
831 | const struct ieee802154_hdr *hdr, | |
832 | struct mac802154_llsec_key *key, __le64 dev_addr) | |
833 | { | |
834 | u8 iv[16]; | |
835 | unsigned char *data; | |
836 | int datalen; | |
837 | struct scatterlist src; | |
838 | struct blkcipher_desc req = { | |
839 | .tfm = key->tfm0, | |
840 | .info = iv, | |
841 | .flags = 0, | |
842 | }; | |
843 | ||
844 | llsec_geniv(iv, dev_addr, &hdr->sec); | |
845 | data = skb_mac_header(skb) + skb->mac_len; | |
846 | datalen = skb_tail_pointer(skb) - data; | |
847 | ||
848 | sg_init_one(&src, data, datalen); | |
849 | ||
850 | return crypto_blkcipher_decrypt_iv(&req, &src, &src, datalen); | |
851 | } | |
852 | ||
853 | static int | |
854 | llsec_do_decrypt_auth(struct sk_buff *skb, const struct mac802154_llsec *sec, | |
855 | const struct ieee802154_hdr *hdr, | |
856 | struct mac802154_llsec_key *key, __le64 dev_addr) | |
857 | { | |
858 | u8 iv[16]; | |
859 | unsigned char *data; | |
860 | int authlen, datalen, assoclen, rc; | |
861 | struct scatterlist src, assoc[2]; | |
862 | struct aead_request *req; | |
863 | ||
864 | authlen = ieee802154_sechdr_authtag_len(&hdr->sec); | |
865 | llsec_geniv(iv, dev_addr, &hdr->sec); | |
866 | ||
867 | req = aead_request_alloc(llsec_tfm_by_len(key, authlen), GFP_ATOMIC); | |
868 | if (!req) | |
869 | return -ENOMEM; | |
870 | ||
871 | sg_init_table(assoc, 2); | |
872 | sg_set_buf(&assoc[0], skb_mac_header(skb), skb->mac_len); | |
873 | assoclen = skb->mac_len; | |
874 | ||
875 | data = skb_mac_header(skb) + skb->mac_len; | |
876 | datalen = skb_tail_pointer(skb) - data; | |
877 | ||
878 | if (hdr->sec.level & IEEE802154_SCF_SECLEVEL_ENC) { | |
879 | sg_set_buf(&assoc[1], data, 0); | |
880 | } else { | |
881 | sg_set_buf(&assoc[1], data, datalen - authlen); | |
882 | assoclen += datalen - authlen; | |
883 | data += datalen - authlen; | |
884 | datalen = authlen; | |
885 | } | |
886 | ||
887 | sg_init_one(&src, data, datalen); | |
888 | ||
889 | aead_request_set_callback(req, 0, NULL, NULL); | |
890 | aead_request_set_assoc(req, assoc, assoclen); | |
891 | aead_request_set_crypt(req, &src, &src, datalen, iv); | |
892 | ||
893 | rc = crypto_aead_decrypt(req); | |
894 | ||
895 | kfree(req); | |
896 | skb_trim(skb, skb->len - authlen); | |
897 | ||
898 | return rc; | |
899 | } | |
900 | ||
901 | static int | |
902 | llsec_do_decrypt(struct sk_buff *skb, const struct mac802154_llsec *sec, | |
903 | const struct ieee802154_hdr *hdr, | |
904 | struct mac802154_llsec_key *key, __le64 dev_addr) | |
905 | { | |
906 | if (hdr->sec.level == IEEE802154_SCF_SECLEVEL_ENC) | |
907 | return llsec_do_decrypt_unauth(skb, sec, hdr, key, dev_addr); | |
908 | else | |
909 | return llsec_do_decrypt_auth(skb, sec, hdr, key, dev_addr); | |
910 | } | |
911 | ||
f0f77dc6 PB |
912 | static int |
913 | llsec_update_devkey_record(struct mac802154_llsec_device *dev, | |
914 | const struct ieee802154_llsec_key_id *in_key) | |
915 | { | |
916 | struct mac802154_llsec_device_key *devkey; | |
917 | ||
918 | devkey = llsec_devkey_find(dev, in_key); | |
919 | ||
920 | if (!devkey) { | |
921 | struct mac802154_llsec_device_key *next; | |
922 | ||
923 | next = kzalloc(sizeof(*devkey), GFP_ATOMIC); | |
924 | if (!next) | |
925 | return -ENOMEM; | |
926 | ||
927 | next->devkey.key_id = *in_key; | |
928 | ||
929 | spin_lock_bh(&dev->lock); | |
930 | ||
931 | devkey = llsec_devkey_find(dev, in_key); | |
932 | if (!devkey) | |
933 | list_add_rcu(&next->devkey.list, &dev->dev.keys); | |
934 | else | |
935 | kfree(next); | |
936 | ||
937 | spin_unlock_bh(&dev->lock); | |
938 | } | |
939 | ||
940 | return 0; | |
941 | } | |
942 | ||
4c14a2fb PB |
943 | static int |
944 | llsec_update_devkey_info(struct mac802154_llsec_device *dev, | |
945 | const struct ieee802154_llsec_key_id *in_key, | |
946 | u32 frame_counter) | |
947 | { | |
948 | struct mac802154_llsec_device_key *devkey = NULL; | |
949 | ||
950 | if (dev->dev.key_mode == IEEE802154_LLSEC_DEVKEY_RESTRICT) { | |
951 | devkey = llsec_devkey_find(dev, in_key); | |
952 | if (!devkey) | |
953 | return -ENOENT; | |
954 | } | |
955 | ||
f0f77dc6 PB |
956 | if (dev->dev.key_mode == IEEE802154_LLSEC_DEVKEY_RECORD) { |
957 | int rc = llsec_update_devkey_record(dev, in_key); | |
958 | ||
959 | if (rc < 0) | |
960 | return rc; | |
961 | } | |
962 | ||
4c14a2fb PB |
963 | spin_lock_bh(&dev->lock); |
964 | ||
965 | if ((!devkey && frame_counter < dev->dev.frame_counter) || | |
966 | (devkey && frame_counter < devkey->devkey.frame_counter)) { | |
967 | spin_unlock_bh(&dev->lock); | |
968 | return -EINVAL; | |
969 | } | |
970 | ||
971 | if (devkey) | |
972 | devkey->devkey.frame_counter = frame_counter + 1; | |
973 | else | |
974 | dev->dev.frame_counter = frame_counter + 1; | |
975 | ||
976 | spin_unlock_bh(&dev->lock); | |
977 | ||
978 | return 0; | |
979 | } | |
980 | ||
981 | int mac802154_llsec_decrypt(struct mac802154_llsec *sec, struct sk_buff *skb) | |
982 | { | |
983 | struct ieee802154_hdr hdr; | |
984 | struct mac802154_llsec_key *key; | |
985 | struct ieee802154_llsec_key_id key_id; | |
986 | struct mac802154_llsec_device *dev; | |
987 | struct ieee802154_llsec_seclevel seclevel; | |
988 | int err; | |
989 | __le64 dev_addr; | |
990 | u32 frame_ctr; | |
991 | ||
992 | if (ieee802154_hdr_peek(skb, &hdr) < 0) | |
993 | return -EINVAL; | |
994 | if (!hdr.fc.security_enabled) | |
995 | return 0; | |
996 | if (hdr.fc.version == 0) | |
997 | return -EINVAL; | |
998 | ||
999 | read_lock_bh(&sec->lock); | |
1000 | if (!sec->params.enabled) { | |
1001 | read_unlock_bh(&sec->lock); | |
1002 | return -EINVAL; | |
1003 | } | |
1004 | read_unlock_bh(&sec->lock); | |
1005 | ||
1006 | rcu_read_lock(); | |
1007 | ||
1008 | key = llsec_lookup_key(sec, &hdr, &hdr.source, &key_id); | |
1009 | if (!key) { | |
1010 | err = -ENOKEY; | |
1011 | goto fail; | |
1012 | } | |
1013 | ||
1014 | dev = llsec_lookup_dev(sec, &hdr.source); | |
1015 | if (!dev) { | |
1016 | err = -EINVAL; | |
1017 | goto fail_dev; | |
1018 | } | |
1019 | ||
1020 | if (llsec_lookup_seclevel(sec, hdr.fc.type, 0, &seclevel) < 0) { | |
1021 | err = -EINVAL; | |
1022 | goto fail_dev; | |
1023 | } | |
1024 | ||
1025 | if (!(seclevel.sec_levels & BIT(hdr.sec.level)) && | |
1026 | (hdr.sec.level == 0 && seclevel.device_override && | |
1027 | !dev->dev.seclevel_exempt)) { | |
1028 | err = -EINVAL; | |
1029 | goto fail_dev; | |
1030 | } | |
1031 | ||
1032 | frame_ctr = le32_to_cpu(hdr.sec.frame_counter); | |
1033 | ||
1034 | if (frame_ctr == 0xffffffff) { | |
1035 | err = -EOVERFLOW; | |
1036 | goto fail_dev; | |
1037 | } | |
1038 | ||
1039 | err = llsec_update_devkey_info(dev, &key_id, frame_ctr); | |
1040 | if (err) | |
1041 | goto fail_dev; | |
1042 | ||
1043 | dev_addr = dev->dev.hwaddr; | |
1044 | ||
1045 | rcu_read_unlock(); | |
1046 | ||
1047 | err = llsec_do_decrypt(skb, sec, &hdr, key, dev_addr); | |
1048 | llsec_key_put(key); | |
1049 | return err; | |
1050 | ||
1051 | fail_dev: | |
1052 | llsec_key_put(key); | |
1053 | fail: | |
1054 | rcu_read_unlock(); | |
1055 | return err; | |
1056 | } |