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 <linux/crypto.h> 21 #include <linux/ieee802154.h> 22 #include <crypto/aead.h> 23 24 #include "ieee802154_i.h" 25 #include "llsec.h" 26 27 static void llsec_key_put(struct mac802154_llsec_key *key); 28 static bool llsec_key_id_equal(const struct ieee802154_llsec_key_id *a, 29 const struct ieee802154_llsec_key_id *b); 30 31 static void llsec_dev_free(struct mac802154_llsec_device *dev); 32 33 void 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 47 void 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 79 int 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 89 int 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 } 118 119 static struct mac802154_llsec_key* 120 llsec_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); 138 if (IS_ERR(key->tfm[i])) 139 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); 148 if (IS_ERR(key->tfm0)) 149 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; 156 157 err_tfm0: 158 crypto_free_blkcipher(key->tfm0); 159 err_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 } 167 168 static 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 } 181 182 static struct mac802154_llsec_key* 183 llsec_key_get(struct mac802154_llsec_key *key) 184 { 185 kref_get(&key->ref); 186 return key; 187 } 188 189 static void llsec_key_put(struct mac802154_llsec_key *key) 190 { 191 kref_put(&key->ref, llsec_key_release); 192 } 193 194 static 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) { 207 case IEEE802154_SCF_KEY_INDEX: 208 return true; 209 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 } 217 218 int 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; 268 269 fail: 270 kfree(new); 271 return -ENOMEM; 272 } 273 274 int 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)) { 285 list_del_rcu(&pos->list); 286 llsec_key_put(mkey); 287 return 0; 288 } 289 } 290 291 return -ENOENT; 292 } 293 294 static 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 } 299 300 static u32 llsec_dev_hash_short(__le16 short_addr, __le16 pan_id) 301 { 302 return ((__force u16)short_addr) << 16 | (__force u16)pan_id; 303 } 304 305 static u64 llsec_dev_hash_long(__le64 hwaddr) 306 { 307 return (__force u64)hwaddr; 308 } 309 310 static struct mac802154_llsec_device* 311 llsec_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 } 325 326 static struct mac802154_llsec_device* 327 llsec_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 } 339 340 static 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 } 355 356 int 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 } 388 389 static void llsec_dev_free_rcu(struct rcu_head *rcu) 390 { 391 llsec_dev_free(container_of(rcu, struct mac802154_llsec_device, rcu)); 392 } 393 394 int 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 } 408 409 static struct mac802154_llsec_device_key* 410 llsec_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 } 425 426 int 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 } 449 450 int 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 } 470 471 static struct mac802154_llsec_seclevel* 472 llsec_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 } 491 492 int 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 } 510 511 int 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 } 525 526 static int llsec_recover_addr(struct mac802154_llsec *sec, 527 struct ieee802154_addr *addr) 528 { 529 __le16 caddr = sec->params.coord_shortaddr; 530 531 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 } 545 546 static struct mac802154_llsec_key* 547 llsec_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; 593 594 found: 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 } 600 601 static 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 } 614 615 static int 616 llsec_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 } 632 633 static struct crypto_aead* 634 llsec_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 } 644 645 static int 646 llsec_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; 653 struct scatterlist sg; 654 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; 662 663 assoclen = skb->mac_len; 664 665 data = skb_mac_header(skb) + skb->mac_len; 666 datalen = skb_tail_pointer(skb) - data; 667 668 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)) { 673 assoclen += datalen; 674 datalen = 0; 675 } 676 677 aead_request_set_callback(req, 0, NULL, NULL); 678 aead_request_set_crypt(req, &sg, &sg, datalen, iv); 679 aead_request_set_ad(req, assoclen); 680 681 rc = crypto_aead_encrypt(req); 682 683 kfree(req); 684 685 return rc; 686 } 687 688 static 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 } 698 699 int 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); 760 761 return rc; 762 763 fail_read: 764 read_unlock_bh(&sec->lock); 765 fail: 766 rcu_read_unlock(); 767 return rc; 768 } 769 770 static struct mac802154_llsec_device* 771 llsec_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 } 803 804 static int 805 llsec_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 } 822 823 static int 824 llsec_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 } 846 847 static int 848 llsec_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; 855 struct scatterlist sg; 856 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; 864 865 assoclen = skb->mac_len; 866 867 data = skb_mac_header(skb) + skb->mac_len; 868 datalen = skb_tail_pointer(skb) - data; 869 870 sg_init_one(&sg, skb_mac_header(skb), assoclen + datalen); 871 872 if (!(hdr->sec.level & IEEE802154_SCF_SECLEVEL_ENC)) { 873 assoclen += datalen - authlen; 874 datalen = authlen; 875 } 876 877 aead_request_set_callback(req, 0, NULL, NULL); 878 aead_request_set_crypt(req, &sg, &sg, datalen, iv); 879 aead_request_set_ad(req, assoclen); 880 881 rc = crypto_aead_decrypt(req); 882 883 kfree(req); 884 skb_trim(skb, skb->len - authlen); 885 886 return rc; 887 } 888 889 static int 890 llsec_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 } 899 900 static int 901 llsec_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 } 930 931 static int 932 llsec_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 } 943 944 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 } 950 951 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 } 968 969 int 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 1039 fail_dev: 1040 llsec_key_put(key); 1041 fail: 1042 rcu_read_unlock(); 1043 return err; 1044 } 1045