blob: 985e9394e2afa97c069a9c565859a04c7a2cff51 [file] [log] [blame]
Phoebe Buckheister5d637d52014-05-16 17:46:37 +02001/*
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>
Herbert Xu8a1a2b72015-04-22 15:06:33 +080020#include <linux/crypto.h>
Alexander Aring4ca24ac2014-10-25 09:41:04 +020021#include <linux/ieee802154.h>
Herbert Xu8a1a2b72015-04-22 15:06:33 +080022#include <crypto/aead.h>
Phoebe Buckheister5d637d52014-05-16 17:46:37 +020023
Alexander Aring0f1556b2014-10-25 09:41:00 +020024#include "ieee802154_i.h"
Phoebe Buckheister5d637d52014-05-16 17:46:37 +020025#include "llsec.h"
26
27static void llsec_key_put(struct mac802154_llsec_key *key);
28static bool llsec_key_id_equal(const struct ieee802154_llsec_key_id *a,
29 const struct ieee802154_llsec_key_id *b);
30
31static void llsec_dev_free(struct mac802154_llsec_device *dev);
32
33void mac802154_llsec_init(struct mac802154_llsec *sec)
34{
35 memset(sec, 0, sizeof(*sec));
36
37 memset(&sec->params.default_key_source, 0xFF, IEEE802154_ADDR_LEN);
38
39 INIT_LIST_HEAD(&sec->table.security_levels);
40 INIT_LIST_HEAD(&sec->table.devices);
41 INIT_LIST_HEAD(&sec->table.keys);
42 hash_init(sec->devices_short);
43 hash_init(sec->devices_hw);
44 rwlock_init(&sec->lock);
45}
46
47void mac802154_llsec_destroy(struct mac802154_llsec *sec)
48{
49 struct ieee802154_llsec_seclevel *sl, *sn;
50 struct ieee802154_llsec_device *dev, *dn;
51 struct ieee802154_llsec_key_entry *key, *kn;
52
53 list_for_each_entry_safe(sl, sn, &sec->table.security_levels, list) {
54 struct mac802154_llsec_seclevel *msl;
55
56 msl = container_of(sl, struct mac802154_llsec_seclevel, level);
57 list_del(&sl->list);
58 kfree(msl);
59 }
60
61 list_for_each_entry_safe(dev, dn, &sec->table.devices, list) {
62 struct mac802154_llsec_device *mdev;
63
64 mdev = container_of(dev, struct mac802154_llsec_device, dev);
65 list_del(&dev->list);
66 llsec_dev_free(mdev);
67 }
68
69 list_for_each_entry_safe(key, kn, &sec->table.keys, list) {
70 struct mac802154_llsec_key *mkey;
71
72 mkey = container_of(key->key, struct mac802154_llsec_key, key);
73 list_del(&key->list);
74 llsec_key_put(mkey);
75 kfree(key);
76 }
77}
78
Phoebe Buckheister5d637d52014-05-16 17:46:37 +020079int mac802154_llsec_get_params(struct mac802154_llsec *sec,
80 struct ieee802154_llsec_params *params)
81{
82 read_lock_bh(&sec->lock);
83 *params = sec->params;
84 read_unlock_bh(&sec->lock);
85
86 return 0;
87}
88
89int mac802154_llsec_set_params(struct mac802154_llsec *sec,
90 const struct ieee802154_llsec_params *params,
91 int changed)
92{
93 write_lock_bh(&sec->lock);
94
95 if (changed & IEEE802154_LLSEC_PARAM_ENABLED)
96 sec->params.enabled = params->enabled;
97 if (changed & IEEE802154_LLSEC_PARAM_FRAME_COUNTER)
98 sec->params.frame_counter = params->frame_counter;
99 if (changed & IEEE802154_LLSEC_PARAM_OUT_LEVEL)
100 sec->params.out_level = params->out_level;
101 if (changed & IEEE802154_LLSEC_PARAM_OUT_KEY)
102 sec->params.out_key = params->out_key;
103 if (changed & IEEE802154_LLSEC_PARAM_KEY_SOURCE)
104 sec->params.default_key_source = params->default_key_source;
105 if (changed & IEEE802154_LLSEC_PARAM_PAN_ID)
106 sec->params.pan_id = params->pan_id;
107 if (changed & IEEE802154_LLSEC_PARAM_HWADDR)
108 sec->params.hwaddr = params->hwaddr;
109 if (changed & IEEE802154_LLSEC_PARAM_COORD_HWADDR)
110 sec->params.coord_hwaddr = params->coord_hwaddr;
111 if (changed & IEEE802154_LLSEC_PARAM_COORD_SHORTADDR)
112 sec->params.coord_shortaddr = params->coord_shortaddr;
113
114 write_unlock_bh(&sec->lock);
115
116 return 0;
117}
118
Phoebe Buckheister5d637d52014-05-16 17:46:37 +0200119static struct mac802154_llsec_key*
120llsec_key_alloc(const struct ieee802154_llsec_key *template)
121{
122 const int authsizes[3] = { 4, 8, 16 };
123 struct mac802154_llsec_key *key;
124 int i;
125
126 key = kzalloc(sizeof(*key), GFP_KERNEL);
127 if (!key)
128 return NULL;
129
130 kref_init(&key->ref);
131 key->key = *template;
132
133 BUILD_BUG_ON(ARRAY_SIZE(authsizes) != ARRAY_SIZE(key->tfm));
134
135 for (i = 0; i < ARRAY_SIZE(key->tfm); i++) {
136 key->tfm[i] = crypto_alloc_aead("ccm(aes)", 0,
137 CRYPTO_ALG_ASYNC);
Wei Yongjun89eb6d02015-04-30 17:44:54 +0200138 if (IS_ERR(key->tfm[i]))
Phoebe Buckheister5d637d52014-05-16 17:46:37 +0200139 goto err_tfm;
140 if (crypto_aead_setkey(key->tfm[i], template->key,
141 IEEE802154_LLSEC_KEY_SIZE))
142 goto err_tfm;
143 if (crypto_aead_setauthsize(key->tfm[i], authsizes[i]))
144 goto err_tfm;
145 }
146
147 key->tfm0 = crypto_alloc_blkcipher("ctr(aes)", 0, CRYPTO_ALG_ASYNC);
Wei Yongjun89eb6d02015-04-30 17:44:54 +0200148 if (IS_ERR(key->tfm0))
Phoebe Buckheister5d637d52014-05-16 17:46:37 +0200149 goto err_tfm;
150
151 if (crypto_blkcipher_setkey(key->tfm0, template->key,
152 IEEE802154_LLSEC_KEY_SIZE))
153 goto err_tfm0;
154
155 return key;
156
157err_tfm0:
158 crypto_free_blkcipher(key->tfm0);
159err_tfm:
160 for (i = 0; i < ARRAY_SIZE(key->tfm); i++)
161 if (key->tfm[i])
162 crypto_free_aead(key->tfm[i]);
163
164 kfree(key);
165 return NULL;
166}
167
168static void llsec_key_release(struct kref *ref)
169{
170 struct mac802154_llsec_key *key;
171 int i;
172
173 key = container_of(ref, struct mac802154_llsec_key, ref);
174
175 for (i = 0; i < ARRAY_SIZE(key->tfm); i++)
176 crypto_free_aead(key->tfm[i]);
177
178 crypto_free_blkcipher(key->tfm0);
179 kfree(key);
180}
181
182static struct mac802154_llsec_key*
183llsec_key_get(struct mac802154_llsec_key *key)
184{
185 kref_get(&key->ref);
186 return key;
187}
188
189static void llsec_key_put(struct mac802154_llsec_key *key)
190{
191 kref_put(&key->ref, llsec_key_release);
192}
193
194static bool llsec_key_id_equal(const struct ieee802154_llsec_key_id *a,
195 const struct ieee802154_llsec_key_id *b)
196{
197 if (a->mode != b->mode)
198 return false;
199
200 if (a->mode == IEEE802154_SCF_KEY_IMPLICIT)
201 return ieee802154_addr_equal(&a->device_addr, &b->device_addr);
202
203 if (a->id != b->id)
204 return false;
205
206 switch (a->mode) {
Phoebe Buckheister53819a62014-05-20 17:51:31 +0200207 case IEEE802154_SCF_KEY_INDEX:
208 return true;
Phoebe Buckheister5d637d52014-05-16 17:46:37 +0200209 case IEEE802154_SCF_KEY_SHORT_INDEX:
210 return a->short_source == b->short_source;
211 case IEEE802154_SCF_KEY_HW_INDEX:
212 return a->extended_source == b->extended_source;
213 }
214
215 return false;
216}
217
218int mac802154_llsec_key_add(struct mac802154_llsec *sec,
219 const struct ieee802154_llsec_key_id *id,
220 const struct ieee802154_llsec_key *key)
221{
222 struct mac802154_llsec_key *mkey = NULL;
223 struct ieee802154_llsec_key_entry *pos, *new;
224
225 if (!(key->frame_types & (1 << IEEE802154_FC_TYPE_MAC_CMD)) &&
226 key->cmd_frame_ids)
227 return -EINVAL;
228
229 list_for_each_entry(pos, &sec->table.keys, list) {
230 if (llsec_key_id_equal(&pos->id, id))
231 return -EEXIST;
232
233 if (memcmp(pos->key->key, key->key,
234 IEEE802154_LLSEC_KEY_SIZE))
235 continue;
236
237 mkey = container_of(pos->key, struct mac802154_llsec_key, key);
238
239 /* Don't allow multiple instances of the same AES key to have
240 * different allowed frame types/command frame ids, as this is
241 * not possible in the 802.15.4 PIB.
242 */
243 if (pos->key->frame_types != key->frame_types ||
244 pos->key->cmd_frame_ids != key->cmd_frame_ids)
245 return -EEXIST;
246
247 break;
248 }
249
250 new = kzalloc(sizeof(*new), GFP_KERNEL);
251 if (!new)
252 return -ENOMEM;
253
254 if (!mkey)
255 mkey = llsec_key_alloc(key);
256 else
257 mkey = llsec_key_get(mkey);
258
259 if (!mkey)
260 goto fail;
261
262 new->id = *id;
263 new->key = &mkey->key;
264
265 list_add_rcu(&new->list, &sec->table.keys);
266
267 return 0;
268
269fail:
270 kfree(new);
271 return -ENOMEM;
272}
273
274int mac802154_llsec_key_del(struct mac802154_llsec *sec,
275 const struct ieee802154_llsec_key_id *key)
276{
277 struct ieee802154_llsec_key_entry *pos;
278
279 list_for_each_entry(pos, &sec->table.keys, list) {
280 struct mac802154_llsec_key *mkey;
281
282 mkey = container_of(pos->key, struct mac802154_llsec_key, key);
283
284 if (llsec_key_id_equal(&pos->id, key)) {
Phoebe Buckheisterfff1f592014-06-06 14:27:52 +0200285 list_del_rcu(&pos->list);
Phoebe Buckheister5d637d52014-05-16 17:46:37 +0200286 llsec_key_put(mkey);
287 return 0;
288 }
289 }
290
291 return -ENOENT;
292}
293
Phoebe Buckheister5d637d52014-05-16 17:46:37 +0200294static bool llsec_dev_use_shortaddr(__le16 short_addr)
295{
296 return short_addr != cpu_to_le16(IEEE802154_ADDR_UNDEF) &&
297 short_addr != cpu_to_le16(0xffff);
298}
299
300static u32 llsec_dev_hash_short(__le16 short_addr, __le16 pan_id)
301{
Stefan Schmidt1db99602014-12-04 11:52:01 +0100302 return ((__force u16)short_addr) << 16 | (__force u16)pan_id;
Phoebe Buckheister5d637d52014-05-16 17:46:37 +0200303}
304
305static u64 llsec_dev_hash_long(__le64 hwaddr)
306{
Stefan Schmidt1db99602014-12-04 11:52:01 +0100307 return (__force u64)hwaddr;
Phoebe Buckheister5d637d52014-05-16 17:46:37 +0200308}
309
310static struct mac802154_llsec_device*
311llsec_dev_find_short(struct mac802154_llsec *sec, __le16 short_addr,
312 __le16 pan_id)
313{
314 struct mac802154_llsec_device *dev;
315 u32 key = llsec_dev_hash_short(short_addr, pan_id);
316
317 hash_for_each_possible_rcu(sec->devices_short, dev, bucket_s, key) {
318 if (dev->dev.short_addr == short_addr &&
319 dev->dev.pan_id == pan_id)
320 return dev;
321 }
322
323 return NULL;
324}
325
326static struct mac802154_llsec_device*
327llsec_dev_find_long(struct mac802154_llsec *sec, __le64 hwaddr)
328{
329 struct mac802154_llsec_device *dev;
330 u64 key = llsec_dev_hash_long(hwaddr);
331
332 hash_for_each_possible_rcu(sec->devices_hw, dev, bucket_hw, key) {
333 if (dev->dev.hwaddr == hwaddr)
334 return dev;
335 }
336
337 return NULL;
338}
339
340static void llsec_dev_free(struct mac802154_llsec_device *dev)
341{
342 struct ieee802154_llsec_device_key *pos, *pn;
343 struct mac802154_llsec_device_key *devkey;
344
345 list_for_each_entry_safe(pos, pn, &dev->dev.keys, list) {
346 devkey = container_of(pos, struct mac802154_llsec_device_key,
347 devkey);
348
349 list_del(&pos->list);
350 kfree(devkey);
351 }
352
353 kfree(dev);
354}
355
356int mac802154_llsec_dev_add(struct mac802154_llsec *sec,
357 const struct ieee802154_llsec_device *dev)
358{
359 struct mac802154_llsec_device *entry;
360 u32 skey = llsec_dev_hash_short(dev->short_addr, dev->pan_id);
361 u64 hwkey = llsec_dev_hash_long(dev->hwaddr);
362
363 BUILD_BUG_ON(sizeof(hwkey) != IEEE802154_ADDR_LEN);
364
365 if ((llsec_dev_use_shortaddr(dev->short_addr) &&
366 llsec_dev_find_short(sec, dev->short_addr, dev->pan_id)) ||
367 llsec_dev_find_long(sec, dev->hwaddr))
368 return -EEXIST;
369
370 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
371 if (!entry)
372 return -ENOMEM;
373
374 entry->dev = *dev;
375 spin_lock_init(&entry->lock);
376 INIT_LIST_HEAD(&entry->dev.keys);
377
378 if (llsec_dev_use_shortaddr(dev->short_addr))
379 hash_add_rcu(sec->devices_short, &entry->bucket_s, skey);
380 else
381 INIT_HLIST_NODE(&entry->bucket_s);
382
383 hash_add_rcu(sec->devices_hw, &entry->bucket_hw, hwkey);
384 list_add_tail_rcu(&entry->dev.list, &sec->table.devices);
385
386 return 0;
387}
388
389static void llsec_dev_free_rcu(struct rcu_head *rcu)
390{
391 llsec_dev_free(container_of(rcu, struct mac802154_llsec_device, rcu));
392}
393
394int mac802154_llsec_dev_del(struct mac802154_llsec *sec, __le64 device_addr)
395{
396 struct mac802154_llsec_device *pos;
397
398 pos = llsec_dev_find_long(sec, device_addr);
399 if (!pos)
400 return -ENOENT;
401
402 hash_del_rcu(&pos->bucket_s);
403 hash_del_rcu(&pos->bucket_hw);
404 call_rcu(&pos->rcu, llsec_dev_free_rcu);
405
406 return 0;
407}
408
Phoebe Buckheister5d637d52014-05-16 17:46:37 +0200409static struct mac802154_llsec_device_key*
410llsec_devkey_find(struct mac802154_llsec_device *dev,
411 const struct ieee802154_llsec_key_id *key)
412{
413 struct ieee802154_llsec_device_key *devkey;
414
415 list_for_each_entry_rcu(devkey, &dev->dev.keys, list) {
416 if (!llsec_key_id_equal(key, &devkey->key_id))
417 continue;
418
419 return container_of(devkey, struct mac802154_llsec_device_key,
420 devkey);
421 }
422
423 return NULL;
424}
425
426int mac802154_llsec_devkey_add(struct mac802154_llsec *sec,
427 __le64 dev_addr,
428 const struct ieee802154_llsec_device_key *key)
429{
430 struct mac802154_llsec_device *dev;
431 struct mac802154_llsec_device_key *devkey;
432
433 dev = llsec_dev_find_long(sec, dev_addr);
434
435 if (!dev)
436 return -ENOENT;
437
438 if (llsec_devkey_find(dev, &key->key_id))
439 return -EEXIST;
440
441 devkey = kmalloc(sizeof(*devkey), GFP_KERNEL);
442 if (!devkey)
443 return -ENOMEM;
444
445 devkey->devkey = *key;
446 list_add_tail_rcu(&devkey->devkey.list, &dev->dev.keys);
447 return 0;
448}
449
450int mac802154_llsec_devkey_del(struct mac802154_llsec *sec,
451 __le64 dev_addr,
452 const struct ieee802154_llsec_device_key *key)
453{
454 struct mac802154_llsec_device *dev;
455 struct mac802154_llsec_device_key *devkey;
456
457 dev = llsec_dev_find_long(sec, dev_addr);
458
459 if (!dev)
460 return -ENOENT;
461
462 devkey = llsec_devkey_find(dev, &key->key_id);
463 if (!devkey)
464 return -ENOENT;
465
466 list_del_rcu(&devkey->devkey.list);
467 kfree_rcu(devkey, rcu);
468 return 0;
469}
470
Phoebe Buckheister5d637d52014-05-16 17:46:37 +0200471static struct mac802154_llsec_seclevel*
472llsec_find_seclevel(const struct mac802154_llsec *sec,
473 const struct ieee802154_llsec_seclevel *sl)
474{
475 struct ieee802154_llsec_seclevel *pos;
476
477 list_for_each_entry(pos, &sec->table.security_levels, list) {
478 if (pos->frame_type != sl->frame_type ||
479 (pos->frame_type == IEEE802154_FC_TYPE_MAC_CMD &&
480 pos->cmd_frame_id != sl->cmd_frame_id) ||
481 pos->device_override != sl->device_override ||
482 pos->sec_levels != sl->sec_levels)
483 continue;
484
485 return container_of(pos, struct mac802154_llsec_seclevel,
486 level);
487 }
488
489 return NULL;
490}
491
492int mac802154_llsec_seclevel_add(struct mac802154_llsec *sec,
493 const struct ieee802154_llsec_seclevel *sl)
494{
495 struct mac802154_llsec_seclevel *entry;
496
497 if (llsec_find_seclevel(sec, sl))
498 return -EEXIST;
499
500 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
501 if (!entry)
502 return -ENOMEM;
503
504 entry->level = *sl;
505
506 list_add_tail_rcu(&entry->level.list, &sec->table.security_levels);
507
508 return 0;
509}
510
511int mac802154_llsec_seclevel_del(struct mac802154_llsec *sec,
512 const struct ieee802154_llsec_seclevel *sl)
513{
514 struct mac802154_llsec_seclevel *pos;
515
516 pos = llsec_find_seclevel(sec, sl);
517 if (!pos)
518 return -ENOENT;
519
520 list_del_rcu(&pos->level.list);
521 kfree_rcu(pos, rcu);
522
523 return 0;
524}
Phoebe Buckheister03556e42014-05-16 17:46:38 +0200525
Phoebe Buckheister03556e42014-05-16 17:46:38 +0200526static int llsec_recover_addr(struct mac802154_llsec *sec,
527 struct ieee802154_addr *addr)
528{
529 __le16 caddr = sec->params.coord_shortaddr;
Varka Bhadram4710d802014-07-02 09:01:09 +0530530
Phoebe Buckheister03556e42014-05-16 17:46:38 +0200531 addr->pan_id = sec->params.pan_id;
532
533 if (caddr == cpu_to_le16(IEEE802154_ADDR_BROADCAST)) {
534 return -EINVAL;
535 } else if (caddr == cpu_to_le16(IEEE802154_ADDR_UNDEF)) {
536 addr->extended_addr = sec->params.coord_hwaddr;
537 addr->mode = IEEE802154_ADDR_LONG;
538 } else {
539 addr->short_addr = sec->params.coord_shortaddr;
540 addr->mode = IEEE802154_ADDR_SHORT;
541 }
542
543 return 0;
544}
545
546static struct mac802154_llsec_key*
547llsec_lookup_key(struct mac802154_llsec *sec,
548 const struct ieee802154_hdr *hdr,
549 const struct ieee802154_addr *addr,
550 struct ieee802154_llsec_key_id *key_id)
551{
552 struct ieee802154_addr devaddr = *addr;
553 u8 key_id_mode = hdr->sec.key_id_mode;
554 struct ieee802154_llsec_key_entry *key_entry;
555 struct mac802154_llsec_key *key;
556
557 if (key_id_mode == IEEE802154_SCF_KEY_IMPLICIT &&
558 devaddr.mode == IEEE802154_ADDR_NONE) {
559 if (hdr->fc.type == IEEE802154_FC_TYPE_BEACON) {
560 devaddr.extended_addr = sec->params.coord_hwaddr;
561 devaddr.mode = IEEE802154_ADDR_LONG;
562 } else if (llsec_recover_addr(sec, &devaddr) < 0) {
563 return NULL;
564 }
565 }
566
567 list_for_each_entry_rcu(key_entry, &sec->table.keys, list) {
568 const struct ieee802154_llsec_key_id *id = &key_entry->id;
569
570 if (!(key_entry->key->frame_types & BIT(hdr->fc.type)))
571 continue;
572
573 if (id->mode != key_id_mode)
574 continue;
575
576 if (key_id_mode == IEEE802154_SCF_KEY_IMPLICIT) {
577 if (ieee802154_addr_equal(&devaddr, &id->device_addr))
578 goto found;
579 } else {
580 if (id->id != hdr->sec.key_id)
581 continue;
582
583 if ((key_id_mode == IEEE802154_SCF_KEY_INDEX) ||
584 (key_id_mode == IEEE802154_SCF_KEY_SHORT_INDEX &&
585 id->short_source == hdr->sec.short_src) ||
586 (key_id_mode == IEEE802154_SCF_KEY_HW_INDEX &&
587 id->extended_source == hdr->sec.extended_src))
588 goto found;
589 }
590 }
591
592 return NULL;
593
594found:
595 key = container_of(key_entry->key, struct mac802154_llsec_key, key);
596 if (key_id)
597 *key_id = key_entry->id;
598 return llsec_key_get(key);
599}
600
Phoebe Buckheister03556e42014-05-16 17:46:38 +0200601static void llsec_geniv(u8 iv[16], __le64 addr,
602 const struct ieee802154_sechdr *sec)
603{
604 __be64 addr_bytes = (__force __be64) swab64((__force u64) addr);
605 __be32 frame_counter = (__force __be32) swab32((__force u32) sec->frame_counter);
606
607 iv[0] = 1; /* L' = L - 1 = 1 */
608 memcpy(iv + 1, &addr_bytes, sizeof(addr_bytes));
609 memcpy(iv + 9, &frame_counter, sizeof(frame_counter));
610 iv[13] = sec->level;
611 iv[14] = 0;
612 iv[15] = 1;
613}
614
615static int
616llsec_do_encrypt_unauth(struct sk_buff *skb, const struct mac802154_llsec *sec,
617 const struct ieee802154_hdr *hdr,
618 struct mac802154_llsec_key *key)
619{
620 u8 iv[16];
621 struct scatterlist src;
622 struct blkcipher_desc req = {
623 .tfm = key->tfm0,
624 .info = iv,
625 .flags = 0,
626 };
627
628 llsec_geniv(iv, sec->params.hwaddr, &hdr->sec);
629 sg_init_one(&src, skb->data, skb->len);
630 return crypto_blkcipher_encrypt_iv(&req, &src, &src, skb->len);
631}
632
633static struct crypto_aead*
634llsec_tfm_by_len(struct mac802154_llsec_key *key, int authlen)
635{
636 int i;
637
638 for (i = 0; i < ARRAY_SIZE(key->tfm); i++)
639 if (crypto_aead_authsize(key->tfm[i]) == authlen)
640 return key->tfm[i];
641
642 BUG();
643}
644
645static int
646llsec_do_encrypt_auth(struct sk_buff *skb, const struct mac802154_llsec *sec,
647 const struct ieee802154_hdr *hdr,
648 struct mac802154_llsec_key *key)
649{
650 u8 iv[16];
651 unsigned char *data;
652 int authlen, assoclen, datalen, rc;
Herbert Xu25528fd2015-05-27 16:03:48 +0800653 struct scatterlist sg;
Phoebe Buckheister03556e42014-05-16 17:46:38 +0200654 struct aead_request *req;
655
656 authlen = ieee802154_sechdr_authtag_len(&hdr->sec);
657 llsec_geniv(iv, sec->params.hwaddr, &hdr->sec);
658
659 req = aead_request_alloc(llsec_tfm_by_len(key, authlen), GFP_ATOMIC);
660 if (!req)
661 return -ENOMEM;
662
Phoebe Buckheister03556e42014-05-16 17:46:38 +0200663 assoclen = skb->mac_len;
664
665 data = skb_mac_header(skb) + skb->mac_len;
666 datalen = skb_tail_pointer(skb) - data;
667
Herbert Xu25528fd2015-05-27 16:03:48 +0800668 skb_put(skb, authlen);
669
670 sg_init_one(&sg, skb_mac_header(skb), assoclen + datalen + authlen);
671
672 if (!(hdr->sec.level & IEEE802154_SCF_SECLEVEL_ENC)) {
Phoebe Buckheister03556e42014-05-16 17:46:38 +0200673 assoclen += datalen;
674 datalen = 0;
675 }
676
Phoebe Buckheister03556e42014-05-16 17:46:38 +0200677 aead_request_set_callback(req, 0, NULL, NULL);
Herbert Xu25528fd2015-05-27 16:03:48 +0800678 aead_request_set_crypt(req, &sg, &sg, datalen, iv);
679 aead_request_set_ad(req, assoclen);
Phoebe Buckheister03556e42014-05-16 17:46:38 +0200680
681 rc = crypto_aead_encrypt(req);
682
683 kfree(req);
684
685 return rc;
686}
687
688static int llsec_do_encrypt(struct sk_buff *skb,
689 const struct mac802154_llsec *sec,
690 const struct ieee802154_hdr *hdr,
691 struct mac802154_llsec_key *key)
692{
693 if (hdr->sec.level == IEEE802154_SCF_SECLEVEL_ENC)
694 return llsec_do_encrypt_unauth(skb, sec, hdr, key);
695 else
696 return llsec_do_encrypt_auth(skb, sec, hdr, key);
697}
698
699int mac802154_llsec_encrypt(struct mac802154_llsec *sec, struct sk_buff *skb)
700{
701 struct ieee802154_hdr hdr;
702 int rc, authlen, hlen;
703 struct mac802154_llsec_key *key;
704 u32 frame_ctr;
705
706 hlen = ieee802154_hdr_pull(skb, &hdr);
707
708 if (hlen < 0 || hdr.fc.type != IEEE802154_FC_TYPE_DATA)
709 return -EINVAL;
710
711 if (!hdr.fc.security_enabled || hdr.sec.level == 0) {
712 skb_push(skb, hlen);
713 return 0;
714 }
715
716 authlen = ieee802154_sechdr_authtag_len(&hdr.sec);
717
718 if (skb->len + hlen + authlen + IEEE802154_MFR_SIZE > IEEE802154_MTU)
719 return -EMSGSIZE;
720
721 rcu_read_lock();
722
723 read_lock_bh(&sec->lock);
724
725 if (!sec->params.enabled) {
726 rc = -EINVAL;
727 goto fail_read;
728 }
729
730 key = llsec_lookup_key(sec, &hdr, &hdr.dest, NULL);
731 if (!key) {
732 rc = -ENOKEY;
733 goto fail_read;
734 }
735
736 read_unlock_bh(&sec->lock);
737
738 write_lock_bh(&sec->lock);
739
740 frame_ctr = be32_to_cpu(sec->params.frame_counter);
741 hdr.sec.frame_counter = cpu_to_le32(frame_ctr);
742 if (frame_ctr == 0xFFFFFFFF) {
743 write_unlock_bh(&sec->lock);
744 llsec_key_put(key);
745 rc = -EOVERFLOW;
746 goto fail;
747 }
748
749 sec->params.frame_counter = cpu_to_be32(frame_ctr + 1);
750
751 write_unlock_bh(&sec->lock);
752
753 rcu_read_unlock();
754
755 skb->mac_len = ieee802154_hdr_push(skb, &hdr);
756 skb_reset_mac_header(skb);
757
758 rc = llsec_do_encrypt(skb, sec, &hdr, key);
759 llsec_key_put(key);
760
Phoebe Buckheister62e9c112014-05-20 13:14:23 +0200761 return rc;
Phoebe Buckheister03556e42014-05-16 17:46:38 +0200762
763fail_read:
Phoebe Buckheister6f3eabc2014-05-20 13:14:22 +0200764 read_unlock_bh(&sec->lock);
Phoebe Buckheister03556e42014-05-16 17:46:38 +0200765fail:
766 rcu_read_unlock();
767 return rc;
768}
Phoebe Buckheister4c14a2f2014-05-16 17:46:39 +0200769
Phoebe Buckheister4c14a2f2014-05-16 17:46:39 +0200770static struct mac802154_llsec_device*
771llsec_lookup_dev(struct mac802154_llsec *sec,
772 const struct ieee802154_addr *addr)
773{
774 struct ieee802154_addr devaddr = *addr;
775 struct mac802154_llsec_device *dev = NULL;
776
777 if (devaddr.mode == IEEE802154_ADDR_NONE &&
778 llsec_recover_addr(sec, &devaddr) < 0)
779 return NULL;
780
781 if (devaddr.mode == IEEE802154_ADDR_SHORT) {
782 u32 key = llsec_dev_hash_short(devaddr.short_addr,
783 devaddr.pan_id);
784
785 hash_for_each_possible_rcu(sec->devices_short, dev,
786 bucket_s, key) {
787 if (dev->dev.pan_id == devaddr.pan_id &&
788 dev->dev.short_addr == devaddr.short_addr)
789 return dev;
790 }
791 } else {
792 u64 key = llsec_dev_hash_long(devaddr.extended_addr);
793
794 hash_for_each_possible_rcu(sec->devices_hw, dev,
795 bucket_hw, key) {
796 if (dev->dev.hwaddr == devaddr.extended_addr)
797 return dev;
798 }
799 }
800
801 return NULL;
802}
803
804static int
805llsec_lookup_seclevel(const struct mac802154_llsec *sec,
806 u8 frame_type, u8 cmd_frame_id,
807 struct ieee802154_llsec_seclevel *rlevel)
808{
809 struct ieee802154_llsec_seclevel *level;
810
811 list_for_each_entry_rcu(level, &sec->table.security_levels, list) {
812 if (level->frame_type == frame_type &&
813 (frame_type != IEEE802154_FC_TYPE_MAC_CMD ||
814 level->cmd_frame_id == cmd_frame_id)) {
815 *rlevel = *level;
816 return 0;
817 }
818 }
819
820 return -EINVAL;
821}
822
823static int
824llsec_do_decrypt_unauth(struct sk_buff *skb, const struct mac802154_llsec *sec,
825 const struct ieee802154_hdr *hdr,
826 struct mac802154_llsec_key *key, __le64 dev_addr)
827{
828 u8 iv[16];
829 unsigned char *data;
830 int datalen;
831 struct scatterlist src;
832 struct blkcipher_desc req = {
833 .tfm = key->tfm0,
834 .info = iv,
835 .flags = 0,
836 };
837
838 llsec_geniv(iv, dev_addr, &hdr->sec);
839 data = skb_mac_header(skb) + skb->mac_len;
840 datalen = skb_tail_pointer(skb) - data;
841
842 sg_init_one(&src, data, datalen);
843
844 return crypto_blkcipher_decrypt_iv(&req, &src, &src, datalen);
845}
846
847static int
848llsec_do_decrypt_auth(struct sk_buff *skb, const struct mac802154_llsec *sec,
849 const struct ieee802154_hdr *hdr,
850 struct mac802154_llsec_key *key, __le64 dev_addr)
851{
852 u8 iv[16];
853 unsigned char *data;
854 int authlen, datalen, assoclen, rc;
Herbert Xu25528fd2015-05-27 16:03:48 +0800855 struct scatterlist sg;
Phoebe Buckheister4c14a2f2014-05-16 17:46:39 +0200856 struct aead_request *req;
857
858 authlen = ieee802154_sechdr_authtag_len(&hdr->sec);
859 llsec_geniv(iv, dev_addr, &hdr->sec);
860
861 req = aead_request_alloc(llsec_tfm_by_len(key, authlen), GFP_ATOMIC);
862 if (!req)
863 return -ENOMEM;
864
Phoebe Buckheister4c14a2f2014-05-16 17:46:39 +0200865 assoclen = skb->mac_len;
866
867 data = skb_mac_header(skb) + skb->mac_len;
868 datalen = skb_tail_pointer(skb) - data;
869
Herbert Xu25528fd2015-05-27 16:03:48 +0800870 sg_init_one(&sg, skb_mac_header(skb), assoclen + datalen);
871
872 if (!(hdr->sec.level & IEEE802154_SCF_SECLEVEL_ENC)) {
Phoebe Buckheister4c14a2f2014-05-16 17:46:39 +0200873 assoclen += datalen - authlen;
Phoebe Buckheister4c14a2f2014-05-16 17:46:39 +0200874 datalen = authlen;
875 }
876
Phoebe Buckheister4c14a2f2014-05-16 17:46:39 +0200877 aead_request_set_callback(req, 0, NULL, NULL);
Herbert Xu25528fd2015-05-27 16:03:48 +0800878 aead_request_set_crypt(req, &sg, &sg, datalen, iv);
879 aead_request_set_ad(req, assoclen);
Phoebe Buckheister4c14a2f2014-05-16 17:46:39 +0200880
881 rc = crypto_aead_decrypt(req);
882
883 kfree(req);
884 skb_trim(skb, skb->len - authlen);
885
886 return rc;
887}
888
889static int
890llsec_do_decrypt(struct sk_buff *skb, const struct mac802154_llsec *sec,
891 const struct ieee802154_hdr *hdr,
892 struct mac802154_llsec_key *key, __le64 dev_addr)
893{
894 if (hdr->sec.level == IEEE802154_SCF_SECLEVEL_ENC)
895 return llsec_do_decrypt_unauth(skb, sec, hdr, key, dev_addr);
896 else
897 return llsec_do_decrypt_auth(skb, sec, hdr, key, dev_addr);
898}
899
900static int
Phoebe Buckheisterf0f77dc2014-05-16 17:46:45 +0200901llsec_update_devkey_record(struct mac802154_llsec_device *dev,
902 const struct ieee802154_llsec_key_id *in_key)
903{
904 struct mac802154_llsec_device_key *devkey;
905
906 devkey = llsec_devkey_find(dev, in_key);
907
908 if (!devkey) {
909 struct mac802154_llsec_device_key *next;
910
911 next = kzalloc(sizeof(*devkey), GFP_ATOMIC);
912 if (!next)
913 return -ENOMEM;
914
915 next->devkey.key_id = *in_key;
916
917 spin_lock_bh(&dev->lock);
918
919 devkey = llsec_devkey_find(dev, in_key);
920 if (!devkey)
921 list_add_rcu(&next->devkey.list, &dev->dev.keys);
922 else
923 kfree(next);
924
925 spin_unlock_bh(&dev->lock);
926 }
927
928 return 0;
929}
930
931static int
Phoebe Buckheister4c14a2f2014-05-16 17:46:39 +0200932llsec_update_devkey_info(struct mac802154_llsec_device *dev,
933 const struct ieee802154_llsec_key_id *in_key,
934 u32 frame_counter)
935{
936 struct mac802154_llsec_device_key *devkey = NULL;
937
938 if (dev->dev.key_mode == IEEE802154_LLSEC_DEVKEY_RESTRICT) {
939 devkey = llsec_devkey_find(dev, in_key);
940 if (!devkey)
941 return -ENOENT;
942 }
943
Phoebe Buckheisterf0f77dc2014-05-16 17:46:45 +0200944 if (dev->dev.key_mode == IEEE802154_LLSEC_DEVKEY_RECORD) {
945 int rc = llsec_update_devkey_record(dev, in_key);
946
947 if (rc < 0)
948 return rc;
949 }
950
Phoebe Buckheister4c14a2f2014-05-16 17:46:39 +0200951 spin_lock_bh(&dev->lock);
952
953 if ((!devkey && frame_counter < dev->dev.frame_counter) ||
954 (devkey && frame_counter < devkey->devkey.frame_counter)) {
955 spin_unlock_bh(&dev->lock);
956 return -EINVAL;
957 }
958
959 if (devkey)
960 devkey->devkey.frame_counter = frame_counter + 1;
961 else
962 dev->dev.frame_counter = frame_counter + 1;
963
964 spin_unlock_bh(&dev->lock);
965
966 return 0;
967}
968
969int mac802154_llsec_decrypt(struct mac802154_llsec *sec, struct sk_buff *skb)
970{
971 struct ieee802154_hdr hdr;
972 struct mac802154_llsec_key *key;
973 struct ieee802154_llsec_key_id key_id;
974 struct mac802154_llsec_device *dev;
975 struct ieee802154_llsec_seclevel seclevel;
976 int err;
977 __le64 dev_addr;
978 u32 frame_ctr;
979
980 if (ieee802154_hdr_peek(skb, &hdr) < 0)
981 return -EINVAL;
982 if (!hdr.fc.security_enabled)
983 return 0;
984 if (hdr.fc.version == 0)
985 return -EINVAL;
986
987 read_lock_bh(&sec->lock);
988 if (!sec->params.enabled) {
989 read_unlock_bh(&sec->lock);
990 return -EINVAL;
991 }
992 read_unlock_bh(&sec->lock);
993
994 rcu_read_lock();
995
996 key = llsec_lookup_key(sec, &hdr, &hdr.source, &key_id);
997 if (!key) {
998 err = -ENOKEY;
999 goto fail;
1000 }
1001
1002 dev = llsec_lookup_dev(sec, &hdr.source);
1003 if (!dev) {
1004 err = -EINVAL;
1005 goto fail_dev;
1006 }
1007
1008 if (llsec_lookup_seclevel(sec, hdr.fc.type, 0, &seclevel) < 0) {
1009 err = -EINVAL;
1010 goto fail_dev;
1011 }
1012
1013 if (!(seclevel.sec_levels & BIT(hdr.sec.level)) &&
1014 (hdr.sec.level == 0 && seclevel.device_override &&
1015 !dev->dev.seclevel_exempt)) {
1016 err = -EINVAL;
1017 goto fail_dev;
1018 }
1019
1020 frame_ctr = le32_to_cpu(hdr.sec.frame_counter);
1021
1022 if (frame_ctr == 0xffffffff) {
1023 err = -EOVERFLOW;
1024 goto fail_dev;
1025 }
1026
1027 err = llsec_update_devkey_info(dev, &key_id, frame_ctr);
1028 if (err)
1029 goto fail_dev;
1030
1031 dev_addr = dev->dev.hwaddr;
1032
1033 rcu_read_unlock();
1034
1035 err = llsec_do_decrypt(skb, sec, &hdr, key, dev_addr);
1036 llsec_key_put(key);
1037 return err;
1038
1039fail_dev:
1040 llsec_key_put(key);
1041fail:
1042 rcu_read_unlock();
1043 return err;
1044}