1 /* 2 * hostapd - PMKSA cache for IEEE 802.11i RSN 3 * Copyright (c) 2004-2008, 2012-2015, Jouni Malinen <j@w1.fi> 4 * 5 * This software may be distributed under the terms of the BSD license. 6 * See README for more details. 7 */ 8 9 #include "utils/includes.h" 10 11 #include "utils/common.h" 12 #include "utils/eloop.h" 13 #include "eapol_auth/eapol_auth_sm.h" 14 #include "eapol_auth/eapol_auth_sm_i.h" 15 #include "radius/radius_das.h" 16 #include "sta_info.h" 17 #include "ap_config.h" 18 #include "pmksa_cache_auth.h" 19 20 21 static const int pmksa_cache_max_entries = 1024; 22 static const int dot11RSNAConfigPMKLifetime = 43200; 23 24 struct rsn_pmksa_cache { 25 #define PMKID_HASH_SIZE 128 26 #define PMKID_HASH(pmkid) (unsigned int) ((pmkid)[0] & 0x7f) 27 struct rsn_pmksa_cache_entry *pmkid[PMKID_HASH_SIZE]; 28 struct rsn_pmksa_cache_entry *pmksa; 29 int pmksa_count; 30 31 void (*free_cb)(struct rsn_pmksa_cache_entry *entry, void *ctx); 32 void *ctx; 33 }; 34 35 36 static void pmksa_cache_set_expiration(struct rsn_pmksa_cache *pmksa); 37 38 39 static void _pmksa_cache_free_entry(struct rsn_pmksa_cache_entry *entry) 40 { 41 os_free(entry->vlan_desc); 42 os_free(entry->identity); 43 wpabuf_free(entry->cui); 44 #ifndef CONFIG_NO_RADIUS 45 radius_free_class(&entry->radius_class); 46 #endif /* CONFIG_NO_RADIUS */ 47 bin_clear_free(entry, sizeof(*entry)); 48 } 49 50 51 void pmksa_cache_free_entry(struct rsn_pmksa_cache *pmksa, 52 struct rsn_pmksa_cache_entry *entry) 53 { 54 struct rsn_pmksa_cache_entry *pos, *prev; 55 unsigned int hash; 56 57 pmksa->pmksa_count--; 58 pmksa->free_cb(entry, pmksa->ctx); 59 60 /* unlink from hash list */ 61 hash = PMKID_HASH(entry->pmkid); 62 pos = pmksa->pmkid[hash]; 63 prev = NULL; 64 while (pos) { 65 if (pos == entry) { 66 if (prev != NULL) 67 prev->hnext = entry->hnext; 68 else 69 pmksa->pmkid[hash] = entry->hnext; 70 break; 71 } 72 prev = pos; 73 pos = pos->hnext; 74 } 75 76 /* unlink from entry list */ 77 pos = pmksa->pmksa; 78 prev = NULL; 79 while (pos) { 80 if (pos == entry) { 81 if (prev != NULL) 82 prev->next = entry->next; 83 else 84 pmksa->pmksa = entry->next; 85 break; 86 } 87 prev = pos; 88 pos = pos->next; 89 } 90 91 _pmksa_cache_free_entry(entry); 92 } 93 94 95 /** 96 * pmksa_cache_auth_flush - Flush all PMKSA cache entries 97 * @pmksa: Pointer to PMKSA cache data from pmksa_cache_auth_init() 98 */ 99 void pmksa_cache_auth_flush(struct rsn_pmksa_cache *pmksa) 100 { 101 while (pmksa->pmksa) { 102 wpa_printf(MSG_DEBUG, "RSN: Flush PMKSA cache entry for " 103 MACSTR, MAC2STR(pmksa->pmksa->spa)); 104 pmksa_cache_free_entry(pmksa, pmksa->pmksa); 105 } 106 } 107 108 109 static void pmksa_cache_expire(void *eloop_ctx, void *timeout_ctx) 110 { 111 struct rsn_pmksa_cache *pmksa = eloop_ctx; 112 struct os_reltime now; 113 114 os_get_reltime(&now); 115 while (pmksa->pmksa && pmksa->pmksa->expiration <= now.sec) { 116 wpa_printf(MSG_DEBUG, "RSN: expired PMKSA cache entry for " 117 MACSTR, MAC2STR(pmksa->pmksa->spa)); 118 pmksa_cache_free_entry(pmksa, pmksa->pmksa); 119 } 120 121 pmksa_cache_set_expiration(pmksa); 122 } 123 124 125 static void pmksa_cache_set_expiration(struct rsn_pmksa_cache *pmksa) 126 { 127 int sec; 128 struct os_reltime now; 129 130 eloop_cancel_timeout(pmksa_cache_expire, pmksa, NULL); 131 if (pmksa->pmksa == NULL) 132 return; 133 os_get_reltime(&now); 134 sec = pmksa->pmksa->expiration - now.sec; 135 if (sec < 0) 136 sec = 0; 137 eloop_register_timeout(sec + 1, 0, pmksa_cache_expire, pmksa, NULL); 138 } 139 140 141 static void pmksa_cache_from_eapol_data(struct rsn_pmksa_cache_entry *entry, 142 struct eapol_state_machine *eapol) 143 { 144 struct vlan_description *vlan_desc; 145 146 if (eapol == NULL) 147 return; 148 149 if (eapol->identity) { 150 entry->identity = os_malloc(eapol->identity_len); 151 if (entry->identity) { 152 entry->identity_len = eapol->identity_len; 153 os_memcpy(entry->identity, eapol->identity, 154 eapol->identity_len); 155 } 156 } 157 158 if (eapol->radius_cui) 159 entry->cui = wpabuf_dup(eapol->radius_cui); 160 161 #ifndef CONFIG_NO_RADIUS 162 radius_copy_class(&entry->radius_class, &eapol->radius_class); 163 #endif /* CONFIG_NO_RADIUS */ 164 165 entry->eap_type_authsrv = eapol->eap_type_authsrv; 166 167 vlan_desc = ((struct sta_info *) eapol->sta)->vlan_desc; 168 if (vlan_desc && vlan_desc->notempty) { 169 entry->vlan_desc = os_zalloc(sizeof(struct vlan_description)); 170 if (entry->vlan_desc) 171 *entry->vlan_desc = *vlan_desc; 172 } else { 173 entry->vlan_desc = NULL; 174 } 175 176 entry->acct_multi_session_id = eapol->acct_multi_session_id; 177 } 178 179 180 void pmksa_cache_to_eapol_data(struct hostapd_data *hapd, 181 struct rsn_pmksa_cache_entry *entry, 182 struct eapol_state_machine *eapol) 183 { 184 if (entry == NULL || eapol == NULL) 185 return; 186 187 if (entry->identity) { 188 os_free(eapol->identity); 189 eapol->identity = os_malloc(entry->identity_len); 190 if (eapol->identity) { 191 eapol->identity_len = entry->identity_len; 192 os_memcpy(eapol->identity, entry->identity, 193 entry->identity_len); 194 } 195 wpa_hexdump_ascii(MSG_DEBUG, "STA identity from PMKSA", 196 eapol->identity, eapol->identity_len); 197 } 198 199 if (entry->cui) { 200 wpabuf_free(eapol->radius_cui); 201 eapol->radius_cui = wpabuf_dup(entry->cui); 202 } 203 204 #ifndef CONFIG_NO_RADIUS 205 radius_free_class(&eapol->radius_class); 206 radius_copy_class(&eapol->radius_class, &entry->radius_class); 207 #endif /* CONFIG_NO_RADIUS */ 208 if (eapol->radius_class.attr) { 209 wpa_printf(MSG_DEBUG, "Copied %lu Class attribute(s) from " 210 "PMKSA", (unsigned long) eapol->radius_class.count); 211 } 212 213 eapol->eap_type_authsrv = entry->eap_type_authsrv; 214 #ifndef CONFIG_NO_VLAN 215 ap_sta_set_vlan(hapd, eapol->sta, entry->vlan_desc); 216 #endif /* CONFIG_NO_VLAN */ 217 218 eapol->acct_multi_session_id = entry->acct_multi_session_id; 219 } 220 221 222 static void pmksa_cache_link_entry(struct rsn_pmksa_cache *pmksa, 223 struct rsn_pmksa_cache_entry *entry) 224 { 225 struct rsn_pmksa_cache_entry *pos, *prev; 226 int hash; 227 228 /* Add the new entry; order by expiration time */ 229 pos = pmksa->pmksa; 230 prev = NULL; 231 while (pos) { 232 if (pos->expiration > entry->expiration) 233 break; 234 prev = pos; 235 pos = pos->next; 236 } 237 if (prev == NULL) { 238 entry->next = pmksa->pmksa; 239 pmksa->pmksa = entry; 240 } else { 241 entry->next = prev->next; 242 prev->next = entry; 243 } 244 245 hash = PMKID_HASH(entry->pmkid); 246 entry->hnext = pmksa->pmkid[hash]; 247 pmksa->pmkid[hash] = entry; 248 249 pmksa->pmksa_count++; 250 if (prev == NULL) 251 pmksa_cache_set_expiration(pmksa); 252 wpa_printf(MSG_DEBUG, "RSN: added PMKSA cache entry for " MACSTR, 253 MAC2STR(entry->spa)); 254 wpa_hexdump(MSG_DEBUG, "RSN: added PMKID", entry->pmkid, PMKID_LEN); 255 } 256 257 258 /** 259 * pmksa_cache_auth_add - Add a PMKSA cache entry 260 * @pmksa: Pointer to PMKSA cache data from pmksa_cache_auth_init() 261 * @pmk: The new pairwise master key 262 * @pmk_len: PMK length in bytes, usually PMK_LEN (32) 263 * @pmkid: Calculated PMKID 264 * @kck: Key confirmation key or %NULL if not yet derived 265 * @kck_len: KCK length in bytes 266 * @aa: Authenticator address 267 * @spa: Supplicant address 268 * @session_timeout: Session timeout 269 * @eapol: Pointer to EAPOL state machine data 270 * @akmp: WPA_KEY_MGMT_* used in key derivation 271 * Returns: Pointer to the added PMKSA cache entry or %NULL on error 272 * 273 * This function create a PMKSA entry for a new PMK and adds it to the PMKSA 274 * cache. If an old entry is already in the cache for the same Supplicant, 275 * this entry will be replaced with the new entry. PMKID will be calculated 276 * based on the PMK. 277 */ 278 struct rsn_pmksa_cache_entry * 279 pmksa_cache_auth_add(struct rsn_pmksa_cache *pmksa, 280 const u8 *pmk, size_t pmk_len, const u8 *pmkid, 281 const u8 *kck, size_t kck_len, 282 const u8 *aa, const u8 *spa, int session_timeout, 283 struct eapol_state_machine *eapol, int akmp) 284 { 285 struct rsn_pmksa_cache_entry *entry, *pos; 286 struct os_reltime now; 287 288 if (pmk_len > PMK_LEN_MAX) 289 return NULL; 290 291 if (wpa_key_mgmt_suite_b(akmp) && !kck) 292 return NULL; 293 294 entry = os_zalloc(sizeof(*entry)); 295 if (entry == NULL) 296 return NULL; 297 os_memcpy(entry->pmk, pmk, pmk_len); 298 entry->pmk_len = pmk_len; 299 if (pmkid) 300 os_memcpy(entry->pmkid, pmkid, PMKID_LEN); 301 else if (akmp == WPA_KEY_MGMT_IEEE8021X_SUITE_B_192) 302 rsn_pmkid_suite_b_192(kck, kck_len, aa, spa, entry->pmkid); 303 else if (wpa_key_mgmt_suite_b(akmp)) 304 rsn_pmkid_suite_b(kck, kck_len, aa, spa, entry->pmkid); 305 else 306 rsn_pmkid(pmk, pmk_len, aa, spa, entry->pmkid, 307 wpa_key_mgmt_sha256(akmp)); 308 os_get_reltime(&now); 309 entry->expiration = now.sec; 310 if (session_timeout > 0) 311 entry->expiration += session_timeout; 312 else 313 entry->expiration += dot11RSNAConfigPMKLifetime; 314 entry->akmp = akmp; 315 os_memcpy(entry->spa, spa, ETH_ALEN); 316 pmksa_cache_from_eapol_data(entry, eapol); 317 318 /* Replace an old entry for the same STA (if found) with the new entry 319 */ 320 pos = pmksa_cache_auth_get(pmksa, spa, NULL); 321 if (pos) 322 pmksa_cache_free_entry(pmksa, pos); 323 324 if (pmksa->pmksa_count >= pmksa_cache_max_entries && pmksa->pmksa) { 325 /* Remove the oldest entry to make room for the new entry */ 326 wpa_printf(MSG_DEBUG, "RSN: removed the oldest PMKSA cache " 327 "entry (for " MACSTR ") to make room for new one", 328 MAC2STR(pmksa->pmksa->spa)); 329 pmksa_cache_free_entry(pmksa, pmksa->pmksa); 330 } 331 332 pmksa_cache_link_entry(pmksa, entry); 333 334 return entry; 335 } 336 337 338 struct rsn_pmksa_cache_entry * 339 pmksa_cache_add_okc(struct rsn_pmksa_cache *pmksa, 340 const struct rsn_pmksa_cache_entry *old_entry, 341 const u8 *aa, const u8 *pmkid) 342 { 343 struct rsn_pmksa_cache_entry *entry; 344 345 entry = os_zalloc(sizeof(*entry)); 346 if (entry == NULL) 347 return NULL; 348 os_memcpy(entry->pmkid, pmkid, PMKID_LEN); 349 os_memcpy(entry->pmk, old_entry->pmk, old_entry->pmk_len); 350 entry->pmk_len = old_entry->pmk_len; 351 entry->expiration = old_entry->expiration; 352 entry->akmp = old_entry->akmp; 353 os_memcpy(entry->spa, old_entry->spa, ETH_ALEN); 354 entry->opportunistic = 1; 355 if (old_entry->identity) { 356 entry->identity = os_malloc(old_entry->identity_len); 357 if (entry->identity) { 358 entry->identity_len = old_entry->identity_len; 359 os_memcpy(entry->identity, old_entry->identity, 360 old_entry->identity_len); 361 } 362 } 363 if (old_entry->cui) 364 entry->cui = wpabuf_dup(old_entry->cui); 365 #ifndef CONFIG_NO_RADIUS 366 radius_copy_class(&entry->radius_class, &old_entry->radius_class); 367 #endif /* CONFIG_NO_RADIUS */ 368 entry->eap_type_authsrv = old_entry->eap_type_authsrv; 369 if (old_entry->vlan_desc) { 370 entry->vlan_desc = os_zalloc(sizeof(struct vlan_description)); 371 if (entry->vlan_desc) 372 *entry->vlan_desc = *old_entry->vlan_desc; 373 } else { 374 entry->vlan_desc = NULL; 375 } 376 entry->opportunistic = 1; 377 378 pmksa_cache_link_entry(pmksa, entry); 379 380 return entry; 381 } 382 383 384 /** 385 * pmksa_cache_auth_deinit - Free all entries in PMKSA cache 386 * @pmksa: Pointer to PMKSA cache data from pmksa_cache_auth_init() 387 */ 388 void pmksa_cache_auth_deinit(struct rsn_pmksa_cache *pmksa) 389 { 390 struct rsn_pmksa_cache_entry *entry, *prev; 391 int i; 392 393 if (pmksa == NULL) 394 return; 395 396 entry = pmksa->pmksa; 397 while (entry) { 398 prev = entry; 399 entry = entry->next; 400 _pmksa_cache_free_entry(prev); 401 } 402 eloop_cancel_timeout(pmksa_cache_expire, pmksa, NULL); 403 pmksa->pmksa_count = 0; 404 pmksa->pmksa = NULL; 405 for (i = 0; i < PMKID_HASH_SIZE; i++) 406 pmksa->pmkid[i] = NULL; 407 os_free(pmksa); 408 } 409 410 411 /** 412 * pmksa_cache_auth_get - Fetch a PMKSA cache entry 413 * @pmksa: Pointer to PMKSA cache data from pmksa_cache_auth_init() 414 * @spa: Supplicant address or %NULL to match any 415 * @pmkid: PMKID or %NULL to match any 416 * Returns: Pointer to PMKSA cache entry or %NULL if no match was found 417 */ 418 struct rsn_pmksa_cache_entry * 419 pmksa_cache_auth_get(struct rsn_pmksa_cache *pmksa, 420 const u8 *spa, const u8 *pmkid) 421 { 422 struct rsn_pmksa_cache_entry *entry; 423 424 if (pmkid) { 425 for (entry = pmksa->pmkid[PMKID_HASH(pmkid)]; entry; 426 entry = entry->hnext) { 427 if ((spa == NULL || 428 os_memcmp(entry->spa, spa, ETH_ALEN) == 0) && 429 os_memcmp(entry->pmkid, pmkid, PMKID_LEN) == 0) 430 return entry; 431 } 432 } else { 433 for (entry = pmksa->pmksa; entry; entry = entry->next) { 434 if (spa == NULL || 435 os_memcmp(entry->spa, spa, ETH_ALEN) == 0) 436 return entry; 437 } 438 } 439 440 return NULL; 441 } 442 443 444 /** 445 * pmksa_cache_get_okc - Fetch a PMKSA cache entry using OKC 446 * @pmksa: Pointer to PMKSA cache data from pmksa_cache_auth_init() 447 * @aa: Authenticator address 448 * @spa: Supplicant address 449 * @pmkid: PMKID 450 * Returns: Pointer to PMKSA cache entry or %NULL if no match was found 451 * 452 * Use opportunistic key caching (OKC) to find a PMK for a supplicant. 453 */ 454 struct rsn_pmksa_cache_entry * pmksa_cache_get_okc( 455 struct rsn_pmksa_cache *pmksa, const u8 *aa, const u8 *spa, 456 const u8 *pmkid) 457 { 458 struct rsn_pmksa_cache_entry *entry; 459 u8 new_pmkid[PMKID_LEN]; 460 461 for (entry = pmksa->pmksa; entry; entry = entry->next) { 462 if (os_memcmp(entry->spa, spa, ETH_ALEN) != 0) 463 continue; 464 rsn_pmkid(entry->pmk, entry->pmk_len, aa, spa, new_pmkid, 465 wpa_key_mgmt_sha256(entry->akmp)); 466 if (os_memcmp(new_pmkid, pmkid, PMKID_LEN) == 0) 467 return entry; 468 } 469 return NULL; 470 } 471 472 473 /** 474 * pmksa_cache_auth_init - Initialize PMKSA cache 475 * @free_cb: Callback function to be called when a PMKSA cache entry is freed 476 * @ctx: Context pointer for free_cb function 477 * Returns: Pointer to PMKSA cache data or %NULL on failure 478 */ 479 struct rsn_pmksa_cache * 480 pmksa_cache_auth_init(void (*free_cb)(struct rsn_pmksa_cache_entry *entry, 481 void *ctx), void *ctx) 482 { 483 struct rsn_pmksa_cache *pmksa; 484 485 pmksa = os_zalloc(sizeof(*pmksa)); 486 if (pmksa) { 487 pmksa->free_cb = free_cb; 488 pmksa->ctx = ctx; 489 } 490 491 return pmksa; 492 } 493 494 495 static int das_attr_match(struct rsn_pmksa_cache_entry *entry, 496 struct radius_das_attrs *attr) 497 { 498 int match = 0; 499 500 if (attr->sta_addr) { 501 if (os_memcmp(attr->sta_addr, entry->spa, ETH_ALEN) != 0) 502 return 0; 503 match++; 504 } 505 506 if (attr->acct_multi_session_id) { 507 char buf[20]; 508 509 if (attr->acct_multi_session_id_len != 16) 510 return 0; 511 os_snprintf(buf, sizeof(buf), "%016llX", 512 (unsigned long long) entry->acct_multi_session_id); 513 if (os_memcmp(attr->acct_multi_session_id, buf, 16) != 0) 514 return 0; 515 match++; 516 } 517 518 if (attr->cui) { 519 if (!entry->cui || 520 attr->cui_len != wpabuf_len(entry->cui) || 521 os_memcmp(attr->cui, wpabuf_head(entry->cui), 522 attr->cui_len) != 0) 523 return 0; 524 match++; 525 } 526 527 if (attr->user_name) { 528 if (!entry->identity || 529 attr->user_name_len != entry->identity_len || 530 os_memcmp(attr->user_name, entry->identity, 531 attr->user_name_len) != 0) 532 return 0; 533 match++; 534 } 535 536 return match; 537 } 538 539 540 int pmksa_cache_auth_radius_das_disconnect(struct rsn_pmksa_cache *pmksa, 541 struct radius_das_attrs *attr) 542 { 543 int found = 0; 544 struct rsn_pmksa_cache_entry *entry, *prev; 545 546 if (attr->acct_session_id) 547 return -1; 548 549 entry = pmksa->pmksa; 550 while (entry) { 551 if (das_attr_match(entry, attr)) { 552 found++; 553 prev = entry; 554 entry = entry->next; 555 pmksa_cache_free_entry(pmksa, prev); 556 continue; 557 } 558 entry = entry->next; 559 } 560 561 return found ? 0 : -1; 562 } 563 564 565 /** 566 * pmksa_cache_auth_list - Dump text list of entries in PMKSA cache 567 * @pmksa: Pointer to PMKSA cache data from pmksa_cache_auth_init() 568 * @buf: Buffer for the list 569 * @len: Length of the buffer 570 * Returns: Number of bytes written to buffer 571 * 572 * This function is used to generate a text format representation of the 573 * current PMKSA cache contents for the ctrl_iface PMKSA command. 574 */ 575 int pmksa_cache_auth_list(struct rsn_pmksa_cache *pmksa, char *buf, size_t len) 576 { 577 int i, ret; 578 char *pos = buf; 579 struct rsn_pmksa_cache_entry *entry; 580 struct os_reltime now; 581 582 os_get_reltime(&now); 583 ret = os_snprintf(pos, buf + len - pos, 584 "Index / SPA / PMKID / expiration (in seconds) / opportunistic\n"); 585 if (os_snprintf_error(buf + len - pos, ret)) 586 return pos - buf; 587 pos += ret; 588 i = 0; 589 entry = pmksa->pmksa; 590 while (entry) { 591 ret = os_snprintf(pos, buf + len - pos, "%d " MACSTR " ", 592 i, MAC2STR(entry->spa)); 593 if (os_snprintf_error(buf + len - pos, ret)) 594 return pos - buf; 595 pos += ret; 596 pos += wpa_snprintf_hex(pos, buf + len - pos, entry->pmkid, 597 PMKID_LEN); 598 ret = os_snprintf(pos, buf + len - pos, " %d %d\n", 599 (int) (entry->expiration - now.sec), 600 entry->opportunistic); 601 if (os_snprintf_error(buf + len - pos, ret)) 602 return pos - buf; 603 pos += ret; 604 entry = entry->next; 605 } 606 return pos - buf; 607 } 608