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> 20 #include <net/ieee802154.h> 21 #include <crypto/algapi.h> 22 23 #include "mac802154.h" 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 78 79 80 int mac802154_llsec_get_params(struct mac802154_llsec *sec, 81 struct ieee802154_llsec_params *params) 82 { 83 read_lock_bh(&sec->lock); 84 *params = sec->params; 85 read_unlock_bh(&sec->lock); 86 87 return 0; 88 } 89 90 int mac802154_llsec_set_params(struct mac802154_llsec *sec, 91 const struct ieee802154_llsec_params *params, 92 int changed) 93 { 94 write_lock_bh(&sec->lock); 95 96 if (changed & IEEE802154_LLSEC_PARAM_ENABLED) 97 sec->params.enabled = params->enabled; 98 if (changed & IEEE802154_LLSEC_PARAM_FRAME_COUNTER) 99 sec->params.frame_counter = params->frame_counter; 100 if (changed & IEEE802154_LLSEC_PARAM_OUT_LEVEL) 101 sec->params.out_level = params->out_level; 102 if (changed & IEEE802154_LLSEC_PARAM_OUT_KEY) 103 sec->params.out_key = params->out_key; 104 if (changed & IEEE802154_LLSEC_PARAM_KEY_SOURCE) 105 sec->params.default_key_source = params->default_key_source; 106 if (changed & IEEE802154_LLSEC_PARAM_PAN_ID) 107 sec->params.pan_id = params->pan_id; 108 if (changed & IEEE802154_LLSEC_PARAM_HWADDR) 109 sec->params.hwaddr = params->hwaddr; 110 if (changed & IEEE802154_LLSEC_PARAM_COORD_HWADDR) 111 sec->params.coord_hwaddr = params->coord_hwaddr; 112 if (changed & IEEE802154_LLSEC_PARAM_COORD_SHORTADDR) 113 sec->params.coord_shortaddr = params->coord_shortaddr; 114 115 write_unlock_bh(&sec->lock); 116 117 return 0; 118 } 119 120 121 122 static struct mac802154_llsec_key* 123 llsec_key_alloc(const struct ieee802154_llsec_key *template) 124 { 125 const int authsizes[3] = { 4, 8, 16 }; 126 struct mac802154_llsec_key *key; 127 int i; 128 129 key = kzalloc(sizeof(*key), GFP_KERNEL); 130 if (!key) 131 return NULL; 132 133 kref_init(&key->ref); 134 key->key = *template; 135 136 BUILD_BUG_ON(ARRAY_SIZE(authsizes) != ARRAY_SIZE(key->tfm)); 137 138 for (i = 0; i < ARRAY_SIZE(key->tfm); i++) { 139 key->tfm[i] = crypto_alloc_aead("ccm(aes)", 0, 140 CRYPTO_ALG_ASYNC); 141 if (!key->tfm[i]) 142 goto err_tfm; 143 if (crypto_aead_setkey(key->tfm[i], template->key, 144 IEEE802154_LLSEC_KEY_SIZE)) 145 goto err_tfm; 146 if (crypto_aead_setauthsize(key->tfm[i], authsizes[i])) 147 goto err_tfm; 148 } 149 150 key->tfm0 = crypto_alloc_blkcipher("ctr(aes)", 0, CRYPTO_ALG_ASYNC); 151 if (!key->tfm0) 152 goto err_tfm; 153 154 if (crypto_blkcipher_setkey(key->tfm0, template->key, 155 IEEE802154_LLSEC_KEY_SIZE)) 156 goto err_tfm0; 157 158 return key; 159 160 err_tfm0: 161 crypto_free_blkcipher(key->tfm0); 162 err_tfm: 163 for (i = 0; i < ARRAY_SIZE(key->tfm); i++) 164 if (key->tfm[i]) 165 crypto_free_aead(key->tfm[i]); 166 167 kfree(key); 168 return NULL; 169 } 170 171 static void llsec_key_release(struct kref *ref) 172 { 173 struct mac802154_llsec_key *key; 174 int i; 175 176 key = container_of(ref, struct mac802154_llsec_key, ref); 177 178 for (i = 0; i < ARRAY_SIZE(key->tfm); i++) 179 crypto_free_aead(key->tfm[i]); 180 181 crypto_free_blkcipher(key->tfm0); 182 kfree(key); 183 } 184 185 static struct mac802154_llsec_key* 186 llsec_key_get(struct mac802154_llsec_key *key) 187 { 188 kref_get(&key->ref); 189 return key; 190 } 191 192 static void llsec_key_put(struct mac802154_llsec_key *key) 193 { 194 kref_put(&key->ref, llsec_key_release); 195 } 196 197 static bool llsec_key_id_equal(const struct ieee802154_llsec_key_id *a, 198 const struct ieee802154_llsec_key_id *b) 199 { 200 if (a->mode != b->mode) 201 return false; 202 203 if (a->mode == IEEE802154_SCF_KEY_IMPLICIT) 204 return ieee802154_addr_equal(&a->device_addr, &b->device_addr); 205 206 if (a->id != b->id) 207 return false; 208 209 switch (a->mode) { 210 case IEEE802154_SCF_KEY_INDEX: 211 return true; 212 case IEEE802154_SCF_KEY_SHORT_INDEX: 213 return a->short_source == b->short_source; 214 case IEEE802154_SCF_KEY_HW_INDEX: 215 return a->extended_source == b->extended_source; 216 } 217 218 return false; 219 } 220 221 int mac802154_llsec_key_add(struct mac802154_llsec *sec, 222 const struct ieee802154_llsec_key_id *id, 223 const struct ieee802154_llsec_key *key) 224 { 225 struct mac802154_llsec_key *mkey = NULL; 226 struct ieee802154_llsec_key_entry *pos, *new; 227 228 if (!(key->frame_types & (1 << IEEE802154_FC_TYPE_MAC_CMD)) && 229 key->cmd_frame_ids) 230 return -EINVAL; 231 232 list_for_each_entry(pos, &sec->table.keys, list) { 233 if (llsec_key_id_equal(&pos->id, id)) 234 return -EEXIST; 235 236 if (memcmp(pos->key->key, key->key, 237 IEEE802154_LLSEC_KEY_SIZE)) 238 continue; 239 240 mkey = container_of(pos->key, struct mac802154_llsec_key, key); 241 242 /* Don't allow multiple instances of the same AES key to have 243 * different allowed frame types/command frame ids, as this is 244 * not possible in the 802.15.4 PIB. 245 */ 246 if (pos->key->frame_types != key->frame_types || 247 pos->key->cmd_frame_ids != key->cmd_frame_ids) 248 return -EEXIST; 249 250 break; 251 } 252 253 new = kzalloc(sizeof(*new), GFP_KERNEL); 254 if (!new) 255 return -ENOMEM; 256 257 if (!mkey) 258 mkey = llsec_key_alloc(key); 259 else 260 mkey = llsec_key_get(mkey); 261 262 if (!mkey) 263 goto fail; 264 265 new->id = *id; 266 new->key = &mkey->key; 267 268 list_add_rcu(&new->list, &sec->table.keys); 269 270 return 0; 271 272 fail: 273 kfree(new); 274 return -ENOMEM; 275 } 276 277 int mac802154_llsec_key_del(struct mac802154_llsec *sec, 278 const struct ieee802154_llsec_key_id *key) 279 { 280 struct ieee802154_llsec_key_entry *pos; 281 282 list_for_each_entry(pos, &sec->table.keys, list) { 283 struct mac802154_llsec_key *mkey; 284 285 mkey = container_of(pos->key, struct mac802154_llsec_key, key); 286 287 if (llsec_key_id_equal(&pos->id, key)) { 288 list_del_rcu(&pos->list); 289 llsec_key_put(mkey); 290 return 0; 291 } 292 } 293 294 return -ENOENT; 295 } 296 297 298 299 static bool llsec_dev_use_shortaddr(__le16 short_addr) 300 { 301 return short_addr != cpu_to_le16(IEEE802154_ADDR_UNDEF) && 302 short_addr != cpu_to_le16(0xffff); 303 } 304 305 static u32 llsec_dev_hash_short(__le16 short_addr, __le16 pan_id) 306 { 307 return ((__force u16) short_addr) << 16 | (__force u16) pan_id; 308 } 309 310 static u64 llsec_dev_hash_long(__le64 hwaddr) 311 { 312 return (__force u64) hwaddr; 313 } 314 315 static struct mac802154_llsec_device* 316 llsec_dev_find_short(struct mac802154_llsec *sec, __le16 short_addr, 317 __le16 pan_id) 318 { 319 struct mac802154_llsec_device *dev; 320 u32 key = llsec_dev_hash_short(short_addr, pan_id); 321 322 hash_for_each_possible_rcu(sec->devices_short, dev, bucket_s, key) { 323 if (dev->dev.short_addr == short_addr && 324 dev->dev.pan_id == pan_id) 325 return dev; 326 } 327 328 return NULL; 329 } 330 331 static struct mac802154_llsec_device* 332 llsec_dev_find_long(struct mac802154_llsec *sec, __le64 hwaddr) 333 { 334 struct mac802154_llsec_device *dev; 335 u64 key = llsec_dev_hash_long(hwaddr); 336 337 hash_for_each_possible_rcu(sec->devices_hw, dev, bucket_hw, key) { 338 if (dev->dev.hwaddr == hwaddr) 339 return dev; 340 } 341 342 return NULL; 343 } 344 345 static void llsec_dev_free(struct mac802154_llsec_device *dev) 346 { 347 struct ieee802154_llsec_device_key *pos, *pn; 348 struct mac802154_llsec_device_key *devkey; 349 350 list_for_each_entry_safe(pos, pn, &dev->dev.keys, list) { 351 devkey = container_of(pos, struct mac802154_llsec_device_key, 352 devkey); 353 354 list_del(&pos->list); 355 kfree(devkey); 356 } 357 358 kfree(dev); 359 } 360 361 int mac802154_llsec_dev_add(struct mac802154_llsec *sec, 362 const struct ieee802154_llsec_device *dev) 363 { 364 struct mac802154_llsec_device *entry; 365 u32 skey = llsec_dev_hash_short(dev->short_addr, dev->pan_id); 366 u64 hwkey = llsec_dev_hash_long(dev->hwaddr); 367 368 BUILD_BUG_ON(sizeof(hwkey) != IEEE802154_ADDR_LEN); 369 370 if ((llsec_dev_use_shortaddr(dev->short_addr) && 371 llsec_dev_find_short(sec, dev->short_addr, dev->pan_id)) || 372 llsec_dev_find_long(sec, dev->hwaddr)) 373 return -EEXIST; 374 375 entry = kmalloc(sizeof(*entry), GFP_KERNEL); 376 if (!entry) 377 return -ENOMEM; 378 379 entry->dev = *dev; 380 spin_lock_init(&entry->lock); 381 INIT_LIST_HEAD(&entry->dev.keys); 382 383 if (llsec_dev_use_shortaddr(dev->short_addr)) 384 hash_add_rcu(sec->devices_short, &entry->bucket_s, skey); 385 else 386 INIT_HLIST_NODE(&entry->bucket_s); 387 388 hash_add_rcu(sec->devices_hw, &entry->bucket_hw, hwkey); 389 list_add_tail_rcu(&entry->dev.list, &sec->table.devices); 390 391 return 0; 392 } 393 394 static void llsec_dev_free_rcu(struct rcu_head *rcu) 395 { 396 llsec_dev_free(container_of(rcu, struct mac802154_llsec_device, rcu)); 397 } 398 399 int mac802154_llsec_dev_del(struct mac802154_llsec *sec, __le64 device_addr) 400 { 401 struct mac802154_llsec_device *pos; 402 403 pos = llsec_dev_find_long(sec, device_addr); 404 if (!pos) 405 return -ENOENT; 406 407 hash_del_rcu(&pos->bucket_s); 408 hash_del_rcu(&pos->bucket_hw); 409 call_rcu(&pos->rcu, llsec_dev_free_rcu); 410 411 return 0; 412 } 413 414 415 416 static struct mac802154_llsec_device_key* 417 llsec_devkey_find(struct mac802154_llsec_device *dev, 418 const struct ieee802154_llsec_key_id *key) 419 { 420 struct ieee802154_llsec_device_key *devkey; 421 422 list_for_each_entry_rcu(devkey, &dev->dev.keys, list) { 423 if (!llsec_key_id_equal(key, &devkey->key_id)) 424 continue; 425 426 return container_of(devkey, struct mac802154_llsec_device_key, 427 devkey); 428 } 429 430 return NULL; 431 } 432 433 int mac802154_llsec_devkey_add(struct mac802154_llsec *sec, 434 __le64 dev_addr, 435 const struct ieee802154_llsec_device_key *key) 436 { 437 struct mac802154_llsec_device *dev; 438 struct mac802154_llsec_device_key *devkey; 439 440 dev = llsec_dev_find_long(sec, dev_addr); 441 442 if (!dev) 443 return -ENOENT; 444 445 if (llsec_devkey_find(dev, &key->key_id)) 446 return -EEXIST; 447 448 devkey = kmalloc(sizeof(*devkey), GFP_KERNEL); 449 if (!devkey) 450 return -ENOMEM; 451 452 devkey->devkey = *key; 453 list_add_tail_rcu(&devkey->devkey.list, &dev->dev.keys); 454 return 0; 455 } 456 457 int mac802154_llsec_devkey_del(struct mac802154_llsec *sec, 458 __le64 dev_addr, 459 const struct ieee802154_llsec_device_key *key) 460 { 461 struct mac802154_llsec_device *dev; 462 struct mac802154_llsec_device_key *devkey; 463 464 dev = llsec_dev_find_long(sec, dev_addr); 465 466 if (!dev) 467 return -ENOENT; 468 469 devkey = llsec_devkey_find(dev, &key->key_id); 470 if (!devkey) 471 return -ENOENT; 472 473 list_del_rcu(&devkey->devkey.list); 474 kfree_rcu(devkey, rcu); 475 return 0; 476 } 477 478 479 480 static struct mac802154_llsec_seclevel* 481 llsec_find_seclevel(const struct mac802154_llsec *sec, 482 const struct ieee802154_llsec_seclevel *sl) 483 { 484 struct ieee802154_llsec_seclevel *pos; 485 486 list_for_each_entry(pos, &sec->table.security_levels, list) { 487 if (pos->frame_type != sl->frame_type || 488 (pos->frame_type == IEEE802154_FC_TYPE_MAC_CMD && 489 pos->cmd_frame_id != sl->cmd_frame_id) || 490 pos->device_override != sl->device_override || 491 pos->sec_levels != sl->sec_levels) 492 continue; 493 494 return container_of(pos, struct mac802154_llsec_seclevel, 495 level); 496 } 497 498 return NULL; 499 } 500 501 int mac802154_llsec_seclevel_add(struct mac802154_llsec *sec, 502 const struct ieee802154_llsec_seclevel *sl) 503 { 504 struct mac802154_llsec_seclevel *entry; 505 506 if (llsec_find_seclevel(sec, sl)) 507 return -EEXIST; 508 509 entry = kmalloc(sizeof(*entry), GFP_KERNEL); 510 if (!entry) 511 return -ENOMEM; 512 513 entry->level = *sl; 514 515 list_add_tail_rcu(&entry->level.list, &sec->table.security_levels); 516 517 return 0; 518 } 519 520 int mac802154_llsec_seclevel_del(struct mac802154_llsec *sec, 521 const struct ieee802154_llsec_seclevel *sl) 522 { 523 struct mac802154_llsec_seclevel *pos; 524 525 pos = llsec_find_seclevel(sec, sl); 526 if (!pos) 527 return -ENOENT; 528 529 list_del_rcu(&pos->level.list); 530 kfree_rcu(pos, rcu); 531 532 return 0; 533 } 534 535 536 537 static int llsec_recover_addr(struct mac802154_llsec *sec, 538 struct ieee802154_addr *addr) 539 { 540 __le16 caddr = sec->params.coord_shortaddr; 541 addr->pan_id = sec->params.pan_id; 542 543 if (caddr == cpu_to_le16(IEEE802154_ADDR_BROADCAST)) { 544 return -EINVAL; 545 } else if (caddr == cpu_to_le16(IEEE802154_ADDR_UNDEF)) { 546 addr->extended_addr = sec->params.coord_hwaddr; 547 addr->mode = IEEE802154_ADDR_LONG; 548 } else { 549 addr->short_addr = sec->params.coord_shortaddr; 550 addr->mode = IEEE802154_ADDR_SHORT; 551 } 552 553 return 0; 554 } 555 556 static struct mac802154_llsec_key* 557 llsec_lookup_key(struct mac802154_llsec *sec, 558 const struct ieee802154_hdr *hdr, 559 const struct ieee802154_addr *addr, 560 struct ieee802154_llsec_key_id *key_id) 561 { 562 struct ieee802154_addr devaddr = *addr; 563 u8 key_id_mode = hdr->sec.key_id_mode; 564 struct ieee802154_llsec_key_entry *key_entry; 565 struct mac802154_llsec_key *key; 566 567 if (key_id_mode == IEEE802154_SCF_KEY_IMPLICIT && 568 devaddr.mode == IEEE802154_ADDR_NONE) { 569 if (hdr->fc.type == IEEE802154_FC_TYPE_BEACON) { 570 devaddr.extended_addr = sec->params.coord_hwaddr; 571 devaddr.mode = IEEE802154_ADDR_LONG; 572 } else if (llsec_recover_addr(sec, &devaddr) < 0) { 573 return NULL; 574 } 575 } 576 577 list_for_each_entry_rcu(key_entry, &sec->table.keys, list) { 578 const struct ieee802154_llsec_key_id *id = &key_entry->id; 579 580 if (!(key_entry->key->frame_types & BIT(hdr->fc.type))) 581 continue; 582 583 if (id->mode != key_id_mode) 584 continue; 585 586 if (key_id_mode == IEEE802154_SCF_KEY_IMPLICIT) { 587 if (ieee802154_addr_equal(&devaddr, &id->device_addr)) 588 goto found; 589 } else { 590 if (id->id != hdr->sec.key_id) 591 continue; 592 593 if ((key_id_mode == IEEE802154_SCF_KEY_INDEX) || 594 (key_id_mode == IEEE802154_SCF_KEY_SHORT_INDEX && 595 id->short_source == hdr->sec.short_src) || 596 (key_id_mode == IEEE802154_SCF_KEY_HW_INDEX && 597 id->extended_source == hdr->sec.extended_src)) 598 goto found; 599 } 600 } 601 602 return NULL; 603 604 found: 605 key = container_of(key_entry->key, struct mac802154_llsec_key, key); 606 if (key_id) 607 *key_id = key_entry->id; 608 return llsec_key_get(key); 609 } 610 611 612 static void llsec_geniv(u8 iv[16], __le64 addr, 613 const struct ieee802154_sechdr *sec) 614 { 615 __be64 addr_bytes = (__force __be64) swab64((__force u64) addr); 616 __be32 frame_counter = (__force __be32) swab32((__force u32) sec->frame_counter); 617 618 iv[0] = 1; /* L' = L - 1 = 1 */ 619 memcpy(iv + 1, &addr_bytes, sizeof(addr_bytes)); 620 memcpy(iv + 9, &frame_counter, sizeof(frame_counter)); 621 iv[13] = sec->level; 622 iv[14] = 0; 623 iv[15] = 1; 624 } 625 626 static int 627 llsec_do_encrypt_unauth(struct sk_buff *skb, const struct mac802154_llsec *sec, 628 const struct ieee802154_hdr *hdr, 629 struct mac802154_llsec_key *key) 630 { 631 u8 iv[16]; 632 struct scatterlist src; 633 struct blkcipher_desc req = { 634 .tfm = key->tfm0, 635 .info = iv, 636 .flags = 0, 637 }; 638 639 llsec_geniv(iv, sec->params.hwaddr, &hdr->sec); 640 sg_init_one(&src, skb->data, skb->len); 641 return crypto_blkcipher_encrypt_iv(&req, &src, &src, skb->len); 642 } 643 644 static struct crypto_aead* 645 llsec_tfm_by_len(struct mac802154_llsec_key *key, int authlen) 646 { 647 int i; 648 649 for (i = 0; i < ARRAY_SIZE(key->tfm); i++) 650 if (crypto_aead_authsize(key->tfm[i]) == authlen) 651 return key->tfm[i]; 652 653 BUG(); 654 } 655 656 static int 657 llsec_do_encrypt_auth(struct sk_buff *skb, const struct mac802154_llsec *sec, 658 const struct ieee802154_hdr *hdr, 659 struct mac802154_llsec_key *key) 660 { 661 u8 iv[16]; 662 unsigned char *data; 663 int authlen, assoclen, datalen, rc; 664 struct scatterlist src, assoc[2], dst[2]; 665 struct aead_request *req; 666 667 authlen = ieee802154_sechdr_authtag_len(&hdr->sec); 668 llsec_geniv(iv, sec->params.hwaddr, &hdr->sec); 669 670 req = aead_request_alloc(llsec_tfm_by_len(key, authlen), GFP_ATOMIC); 671 if (!req) 672 return -ENOMEM; 673 674 sg_init_table(assoc, 2); 675 sg_set_buf(&assoc[0], skb_mac_header(skb), skb->mac_len); 676 assoclen = skb->mac_len; 677 678 data = skb_mac_header(skb) + skb->mac_len; 679 datalen = skb_tail_pointer(skb) - data; 680 681 if (hdr->sec.level & IEEE802154_SCF_SECLEVEL_ENC) { 682 sg_set_buf(&assoc[1], data, 0); 683 } else { 684 sg_set_buf(&assoc[1], data, datalen); 685 assoclen += datalen; 686 datalen = 0; 687 } 688 689 sg_init_one(&src, data, datalen); 690 691 sg_init_table(dst, 2); 692 sg_set_buf(&dst[0], data, datalen); 693 sg_set_buf(&dst[1], skb_put(skb, authlen), authlen); 694 695 aead_request_set_callback(req, 0, NULL, NULL); 696 aead_request_set_assoc(req, assoc, assoclen); 697 aead_request_set_crypt(req, &src, dst, datalen, iv); 698 699 rc = crypto_aead_encrypt(req); 700 701 kfree(req); 702 703 return rc; 704 } 705 706 static int llsec_do_encrypt(struct sk_buff *skb, 707 const struct mac802154_llsec *sec, 708 const struct ieee802154_hdr *hdr, 709 struct mac802154_llsec_key *key) 710 { 711 if (hdr->sec.level == IEEE802154_SCF_SECLEVEL_ENC) 712 return llsec_do_encrypt_unauth(skb, sec, hdr, key); 713 else 714 return llsec_do_encrypt_auth(skb, sec, hdr, key); 715 } 716 717 int mac802154_llsec_encrypt(struct mac802154_llsec *sec, struct sk_buff *skb) 718 { 719 struct ieee802154_hdr hdr; 720 int rc, authlen, hlen; 721 struct mac802154_llsec_key *key; 722 u32 frame_ctr; 723 724 hlen = ieee802154_hdr_pull(skb, &hdr); 725 726 if (hlen < 0 || hdr.fc.type != IEEE802154_FC_TYPE_DATA) 727 return -EINVAL; 728 729 if (!hdr.fc.security_enabled || hdr.sec.level == 0) { 730 skb_push(skb, hlen); 731 return 0; 732 } 733 734 authlen = ieee802154_sechdr_authtag_len(&hdr.sec); 735 736 if (skb->len + hlen + authlen + IEEE802154_MFR_SIZE > IEEE802154_MTU) 737 return -EMSGSIZE; 738 739 rcu_read_lock(); 740 741 read_lock_bh(&sec->lock); 742 743 if (!sec->params.enabled) { 744 rc = -EINVAL; 745 goto fail_read; 746 } 747 748 key = llsec_lookup_key(sec, &hdr, &hdr.dest, NULL); 749 if (!key) { 750 rc = -ENOKEY; 751 goto fail_read; 752 } 753 754 read_unlock_bh(&sec->lock); 755 756 write_lock_bh(&sec->lock); 757 758 frame_ctr = be32_to_cpu(sec->params.frame_counter); 759 hdr.sec.frame_counter = cpu_to_le32(frame_ctr); 760 if (frame_ctr == 0xFFFFFFFF) { 761 write_unlock_bh(&sec->lock); 762 llsec_key_put(key); 763 rc = -EOVERFLOW; 764 goto fail; 765 } 766 767 sec->params.frame_counter = cpu_to_be32(frame_ctr + 1); 768 769 write_unlock_bh(&sec->lock); 770 771 rcu_read_unlock(); 772 773 skb->mac_len = ieee802154_hdr_push(skb, &hdr); 774 skb_reset_mac_header(skb); 775 776 rc = llsec_do_encrypt(skb, sec, &hdr, key); 777 llsec_key_put(key); 778 779 return rc; 780 781 fail_read: 782 read_unlock_bh(&sec->lock); 783 fail: 784 rcu_read_unlock(); 785 return rc; 786 } 787 788 789 790 static struct mac802154_llsec_device* 791 llsec_lookup_dev(struct mac802154_llsec *sec, 792 const struct ieee802154_addr *addr) 793 { 794 struct ieee802154_addr devaddr = *addr; 795 struct mac802154_llsec_device *dev = NULL; 796 797 if (devaddr.mode == IEEE802154_ADDR_NONE && 798 llsec_recover_addr(sec, &devaddr) < 0) 799 return NULL; 800 801 if (devaddr.mode == IEEE802154_ADDR_SHORT) { 802 u32 key = llsec_dev_hash_short(devaddr.short_addr, 803 devaddr.pan_id); 804 805 hash_for_each_possible_rcu(sec->devices_short, dev, 806 bucket_s, key) { 807 if (dev->dev.pan_id == devaddr.pan_id && 808 dev->dev.short_addr == devaddr.short_addr) 809 return dev; 810 } 811 } else { 812 u64 key = llsec_dev_hash_long(devaddr.extended_addr); 813 814 hash_for_each_possible_rcu(sec->devices_hw, dev, 815 bucket_hw, key) { 816 if (dev->dev.hwaddr == devaddr.extended_addr) 817 return dev; 818 } 819 } 820 821 return NULL; 822 } 823 824 static int 825 llsec_lookup_seclevel(const struct mac802154_llsec *sec, 826 u8 frame_type, u8 cmd_frame_id, 827 struct ieee802154_llsec_seclevel *rlevel) 828 { 829 struct ieee802154_llsec_seclevel *level; 830 831 list_for_each_entry_rcu(level, &sec->table.security_levels, list) { 832 if (level->frame_type == frame_type && 833 (frame_type != IEEE802154_FC_TYPE_MAC_CMD || 834 level->cmd_frame_id == cmd_frame_id)) { 835 *rlevel = *level; 836 return 0; 837 } 838 } 839 840 return -EINVAL; 841 } 842 843 static int 844 llsec_do_decrypt_unauth(struct sk_buff *skb, const struct mac802154_llsec *sec, 845 const struct ieee802154_hdr *hdr, 846 struct mac802154_llsec_key *key, __le64 dev_addr) 847 { 848 u8 iv[16]; 849 unsigned char *data; 850 int datalen; 851 struct scatterlist src; 852 struct blkcipher_desc req = { 853 .tfm = key->tfm0, 854 .info = iv, 855 .flags = 0, 856 }; 857 858 llsec_geniv(iv, dev_addr, &hdr->sec); 859 data = skb_mac_header(skb) + skb->mac_len; 860 datalen = skb_tail_pointer(skb) - data; 861 862 sg_init_one(&src, data, datalen); 863 864 return crypto_blkcipher_decrypt_iv(&req, &src, &src, datalen); 865 } 866 867 static int 868 llsec_do_decrypt_auth(struct sk_buff *skb, const struct mac802154_llsec *sec, 869 const struct ieee802154_hdr *hdr, 870 struct mac802154_llsec_key *key, __le64 dev_addr) 871 { 872 u8 iv[16]; 873 unsigned char *data; 874 int authlen, datalen, assoclen, rc; 875 struct scatterlist src, assoc[2]; 876 struct aead_request *req; 877 878 authlen = ieee802154_sechdr_authtag_len(&hdr->sec); 879 llsec_geniv(iv, dev_addr, &hdr->sec); 880 881 req = aead_request_alloc(llsec_tfm_by_len(key, authlen), GFP_ATOMIC); 882 if (!req) 883 return -ENOMEM; 884 885 sg_init_table(assoc, 2); 886 sg_set_buf(&assoc[0], skb_mac_header(skb), skb->mac_len); 887 assoclen = skb->mac_len; 888 889 data = skb_mac_header(skb) + skb->mac_len; 890 datalen = skb_tail_pointer(skb) - data; 891 892 if (hdr->sec.level & IEEE802154_SCF_SECLEVEL_ENC) { 893 sg_set_buf(&assoc[1], data, 0); 894 } else { 895 sg_set_buf(&assoc[1], data, datalen - authlen); 896 assoclen += datalen - authlen; 897 data += datalen - authlen; 898 datalen = authlen; 899 } 900 901 sg_init_one(&src, data, datalen); 902 903 aead_request_set_callback(req, 0, NULL, NULL); 904 aead_request_set_assoc(req, assoc, assoclen); 905 aead_request_set_crypt(req, &src, &src, datalen, iv); 906 907 rc = crypto_aead_decrypt(req); 908 909 kfree(req); 910 skb_trim(skb, skb->len - authlen); 911 912 return rc; 913 } 914 915 static int 916 llsec_do_decrypt(struct sk_buff *skb, const struct mac802154_llsec *sec, 917 const struct ieee802154_hdr *hdr, 918 struct mac802154_llsec_key *key, __le64 dev_addr) 919 { 920 if (hdr->sec.level == IEEE802154_SCF_SECLEVEL_ENC) 921 return llsec_do_decrypt_unauth(skb, sec, hdr, key, dev_addr); 922 else 923 return llsec_do_decrypt_auth(skb, sec, hdr, key, dev_addr); 924 } 925 926 static int 927 llsec_update_devkey_record(struct mac802154_llsec_device *dev, 928 const struct ieee802154_llsec_key_id *in_key) 929 { 930 struct mac802154_llsec_device_key *devkey; 931 932 devkey = llsec_devkey_find(dev, in_key); 933 934 if (!devkey) { 935 struct mac802154_llsec_device_key *next; 936 937 next = kzalloc(sizeof(*devkey), GFP_ATOMIC); 938 if (!next) 939 return -ENOMEM; 940 941 next->devkey.key_id = *in_key; 942 943 spin_lock_bh(&dev->lock); 944 945 devkey = llsec_devkey_find(dev, in_key); 946 if (!devkey) 947 list_add_rcu(&next->devkey.list, &dev->dev.keys); 948 else 949 kfree(next); 950 951 spin_unlock_bh(&dev->lock); 952 } 953 954 return 0; 955 } 956 957 static int 958 llsec_update_devkey_info(struct mac802154_llsec_device *dev, 959 const struct ieee802154_llsec_key_id *in_key, 960 u32 frame_counter) 961 { 962 struct mac802154_llsec_device_key *devkey = NULL; 963 964 if (dev->dev.key_mode == IEEE802154_LLSEC_DEVKEY_RESTRICT) { 965 devkey = llsec_devkey_find(dev, in_key); 966 if (!devkey) 967 return -ENOENT; 968 } 969 970 if (dev->dev.key_mode == IEEE802154_LLSEC_DEVKEY_RECORD) { 971 int rc = llsec_update_devkey_record(dev, in_key); 972 973 if (rc < 0) 974 return rc; 975 } 976 977 spin_lock_bh(&dev->lock); 978 979 if ((!devkey && frame_counter < dev->dev.frame_counter) || 980 (devkey && frame_counter < devkey->devkey.frame_counter)) { 981 spin_unlock_bh(&dev->lock); 982 return -EINVAL; 983 } 984 985 if (devkey) 986 devkey->devkey.frame_counter = frame_counter + 1; 987 else 988 dev->dev.frame_counter = frame_counter + 1; 989 990 spin_unlock_bh(&dev->lock); 991 992 return 0; 993 } 994 995 int mac802154_llsec_decrypt(struct mac802154_llsec *sec, struct sk_buff *skb) 996 { 997 struct ieee802154_hdr hdr; 998 struct mac802154_llsec_key *key; 999 struct ieee802154_llsec_key_id key_id; 1000 struct mac802154_llsec_device *dev; 1001 struct ieee802154_llsec_seclevel seclevel; 1002 int err; 1003 __le64 dev_addr; 1004 u32 frame_ctr; 1005 1006 if (ieee802154_hdr_peek(skb, &hdr) < 0) 1007 return -EINVAL; 1008 if (!hdr.fc.security_enabled) 1009 return 0; 1010 if (hdr.fc.version == 0) 1011 return -EINVAL; 1012 1013 read_lock_bh(&sec->lock); 1014 if (!sec->params.enabled) { 1015 read_unlock_bh(&sec->lock); 1016 return -EINVAL; 1017 } 1018 read_unlock_bh(&sec->lock); 1019 1020 rcu_read_lock(); 1021 1022 key = llsec_lookup_key(sec, &hdr, &hdr.source, &key_id); 1023 if (!key) { 1024 err = -ENOKEY; 1025 goto fail; 1026 } 1027 1028 dev = llsec_lookup_dev(sec, &hdr.source); 1029 if (!dev) { 1030 err = -EINVAL; 1031 goto fail_dev; 1032 } 1033 1034 if (llsec_lookup_seclevel(sec, hdr.fc.type, 0, &seclevel) < 0) { 1035 err = -EINVAL; 1036 goto fail_dev; 1037 } 1038 1039 if (!(seclevel.sec_levels & BIT(hdr.sec.level)) && 1040 (hdr.sec.level == 0 && seclevel.device_override && 1041 !dev->dev.seclevel_exempt)) { 1042 err = -EINVAL; 1043 goto fail_dev; 1044 } 1045 1046 frame_ctr = le32_to_cpu(hdr.sec.frame_counter); 1047 1048 if (frame_ctr == 0xffffffff) { 1049 err = -EOVERFLOW; 1050 goto fail_dev; 1051 } 1052 1053 err = llsec_update_devkey_info(dev, &key_id, frame_ctr); 1054 if (err) 1055 goto fail_dev; 1056 1057 dev_addr = dev->dev.hwaddr; 1058 1059 rcu_read_unlock(); 1060 1061 err = llsec_do_decrypt(skb, sec, &hdr, key, dev_addr); 1062 llsec_key_put(key); 1063 return err; 1064 1065 fail_dev: 1066 llsec_key_put(key); 1067 fail: 1068 rcu_read_unlock(); 1069 return err; 1070 } 1071