2 * WPA Supplicant - RSN PMKSA cache
3 * Copyright (c) 2004-2009, 2011-2015, Jouni Malinen <j@w1.fi>
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
13 #include "eapol_supp/eapol_supp_sm.h"
16 #include "pmksa_cache.h"
18 #if defined(IEEE8021X_EAPOL) && !defined(CONFIG_NO_WPA)
20 static const int pmksa_cache_max_entries = 32;
22 struct rsn_pmksa_cache {
23 struct rsn_pmksa_cache_entry *pmksa; /* PMKSA cache */
24 int pmksa_count; /* number of entries in PMKSA cache */
25 struct wpa_sm *sm; /* TODO: get rid of this reference(?) */
27 void (*free_cb)(struct rsn_pmksa_cache_entry *entry, void *ctx,
28 enum pmksa_free_reason reason);
33 static void pmksa_cache_set_expiration(struct rsn_pmksa_cache *pmksa);
36 static void _pmksa_cache_free_entry(struct rsn_pmksa_cache_entry *entry)
38 bin_clear_free(entry, sizeof(*entry));
42 static void pmksa_cache_free_entry(struct rsn_pmksa_cache *pmksa,
43 struct rsn_pmksa_cache_entry *entry,
44 enum pmksa_free_reason reason)
46 wpa_sm_remove_pmkid(pmksa->sm, entry->network_ctx, entry->aa,
48 entry->fils_cache_id_set ? entry->fils_cache_id :
51 pmksa->free_cb(entry, pmksa->ctx, reason);
52 _pmksa_cache_free_entry(entry);
56 static void pmksa_cache_expire(void *eloop_ctx, void *timeout_ctx)
58 struct rsn_pmksa_cache *pmksa = eloop_ctx;
59 struct os_reltime now;
62 while (pmksa->pmksa && pmksa->pmksa->expiration <= now.sec) {
63 struct rsn_pmksa_cache_entry *entry = pmksa->pmksa;
64 pmksa->pmksa = entry->next;
65 wpa_printf(MSG_DEBUG, "RSN: expired PMKSA cache entry for "
66 MACSTR, MAC2STR(entry->aa));
67 pmksa_cache_free_entry(pmksa, entry, PMKSA_EXPIRE);
70 pmksa_cache_set_expiration(pmksa);
74 static void pmksa_cache_reauth(void *eloop_ctx, void *timeout_ctx)
76 struct rsn_pmksa_cache *pmksa = eloop_ctx;
77 pmksa->sm->cur_pmksa = NULL;
78 eapol_sm_request_reauth(pmksa->sm->eapol);
82 static void pmksa_cache_set_expiration(struct rsn_pmksa_cache *pmksa)
85 struct rsn_pmksa_cache_entry *entry;
86 struct os_reltime now;
88 eloop_cancel_timeout(pmksa_cache_expire, pmksa, NULL);
89 eloop_cancel_timeout(pmksa_cache_reauth, pmksa, NULL);
90 if (pmksa->pmksa == NULL)
93 sec = pmksa->pmksa->expiration - now.sec;
96 eloop_register_timeout(sec + 1, 0, pmksa_cache_expire, pmksa, NULL);
98 entry = pmksa->sm->cur_pmksa ? pmksa->sm->cur_pmksa :
99 pmksa_cache_get(pmksa, pmksa->sm->bssid, NULL, NULL, 0);
101 sec = pmksa->pmksa->reauth_time - now.sec;
104 eloop_register_timeout(sec, 0, pmksa_cache_reauth, pmksa,
111 * pmksa_cache_add - Add a PMKSA cache entry
112 * @pmksa: Pointer to PMKSA cache data from pmksa_cache_init()
113 * @pmk: The new pairwise master key
114 * @pmk_len: PMK length in bytes, usually PMK_LEN (32)
115 * @pmkid: Calculated PMKID
116 * @kck: Key confirmation key or %NULL if not yet derived
117 * @kck_len: KCK length in bytes
118 * @aa: Authenticator address
119 * @spa: Supplicant address
120 * @network_ctx: Network configuration context for this PMK
121 * @akmp: WPA_KEY_MGMT_* used in key derivation
122 * @cache_id: Pointer to FILS Cache Identifier or %NULL if not advertised
123 * Returns: Pointer to the added PMKSA cache entry or %NULL on error
125 * This function create a PMKSA entry for a new PMK and adds it to the PMKSA
126 * cache. If an old entry is already in the cache for the same Authenticator,
127 * this entry will be replaced with the new entry. PMKID will be calculated
128 * based on the PMK and the driver interface is notified of the new PMKID.
130 struct rsn_pmksa_cache_entry *
131 pmksa_cache_add(struct rsn_pmksa_cache *pmksa, const u8 *pmk, size_t pmk_len,
132 const u8 *pmkid, const u8 *kck, size_t kck_len,
133 const u8 *aa, const u8 *spa, void *network_ctx, int akmp,
136 struct rsn_pmksa_cache_entry *entry;
137 struct os_reltime now;
139 if (pmk_len > PMK_LEN_MAX)
142 if (wpa_key_mgmt_suite_b(akmp) && !kck)
145 entry = os_zalloc(sizeof(*entry));
148 os_memcpy(entry->pmk, pmk, pmk_len);
149 entry->pmk_len = pmk_len;
151 os_memcpy(entry->pmkid, pmkid, PMKID_LEN);
152 else if (akmp == WPA_KEY_MGMT_IEEE8021X_SUITE_B_192)
153 rsn_pmkid_suite_b_192(kck, kck_len, aa, spa, entry->pmkid);
154 else if (wpa_key_mgmt_suite_b(akmp))
155 rsn_pmkid_suite_b(kck, kck_len, aa, spa, entry->pmkid);
157 rsn_pmkid(pmk, pmk_len, aa, spa, entry->pmkid, akmp);
158 os_get_reltime(&now);
159 entry->expiration = now.sec + pmksa->sm->dot11RSNAConfigPMKLifetime;
160 entry->reauth_time = now.sec + pmksa->sm->dot11RSNAConfigPMKLifetime *
161 pmksa->sm->dot11RSNAConfigPMKReauthThreshold / 100;
164 entry->fils_cache_id_set = 1;
165 os_memcpy(entry->fils_cache_id, cache_id, FILS_CACHE_ID_LEN);
167 os_memcpy(entry->aa, aa, ETH_ALEN);
168 entry->network_ctx = network_ctx;
170 return pmksa_cache_add_entry(pmksa, entry);
174 struct rsn_pmksa_cache_entry *
175 pmksa_cache_add_entry(struct rsn_pmksa_cache *pmksa,
176 struct rsn_pmksa_cache_entry *entry)
178 struct rsn_pmksa_cache_entry *pos, *prev;
180 /* Replace an old entry for the same Authenticator (if found) with the
185 if (os_memcmp(entry->aa, pos->aa, ETH_ALEN) == 0) {
186 if (pos->pmk_len == entry->pmk_len &&
187 os_memcmp_const(pos->pmk, entry->pmk,
188 entry->pmk_len) == 0 &&
189 os_memcmp_const(pos->pmkid, entry->pmkid,
191 wpa_printf(MSG_DEBUG, "WPA: reusing previous "
197 pmksa->pmksa = pos->next;
199 prev->next = pos->next;
202 * If OKC is used, there may be other PMKSA cache
203 * entries based on the same PMK. These needs to be
204 * flushed so that a new entry can be created based on
205 * the new PMK. Only clear other entries if they have a
206 * matching PMK and this PMK has been used successfully
207 * with the current AP, i.e., if opportunistic flag has
208 * been cleared in wpa_supplicant_key_neg_complete().
210 wpa_printf(MSG_DEBUG, "RSN: Replace PMKSA entry for "
211 "the current AP and any PMKSA cache entry "
212 "that was based on the old PMK");
213 if (!pos->opportunistic)
214 pmksa_cache_flush(pmksa, entry->network_ctx,
215 pos->pmk, pos->pmk_len);
216 pmksa_cache_free_entry(pmksa, pos, PMKSA_REPLACE);
223 if (pmksa->pmksa_count >= pmksa_cache_max_entries && pmksa->pmksa) {
224 /* Remove the oldest entry to make room for the new entry */
227 if (pos == pmksa->sm->cur_pmksa) {
229 * Never remove the current PMKSA cache entry, since
230 * it's in use, and removing it triggers a needless
234 pmksa->pmksa->next = pos ? pos->next : NULL;
236 pmksa->pmksa = pos->next;
239 wpa_printf(MSG_DEBUG, "RSN: removed the oldest idle "
240 "PMKSA cache entry (for " MACSTR ") to "
241 "make room for new one",
243 pmksa_cache_free_entry(pmksa, pos, PMKSA_FREE);
247 /* Add the new entry; order by expiration time */
251 if (pos->expiration > entry->expiration)
257 entry->next = pmksa->pmksa;
258 pmksa->pmksa = entry;
259 pmksa_cache_set_expiration(pmksa);
261 entry->next = prev->next;
264 pmksa->pmksa_count++;
265 wpa_printf(MSG_DEBUG, "RSN: Added PMKSA cache entry for " MACSTR
266 " network_ctx=%p", MAC2STR(entry->aa), entry->network_ctx);
267 wpa_sm_add_pmkid(pmksa->sm, entry->network_ctx, entry->aa, entry->pmkid,
268 entry->fils_cache_id_set ? entry->fils_cache_id : NULL,
269 entry->pmk, entry->pmk_len);
276 * pmksa_cache_flush - Flush PMKSA cache entries for a specific network
277 * @pmksa: Pointer to PMKSA cache data from pmksa_cache_init()
278 * @network_ctx: Network configuration context or %NULL to flush all entries
279 * @pmk: PMK to match for or %NYLL to match all PMKs
280 * @pmk_len: PMK length
282 void pmksa_cache_flush(struct rsn_pmksa_cache *pmksa, void *network_ctx,
283 const u8 *pmk, size_t pmk_len)
285 struct rsn_pmksa_cache_entry *entry, *prev = NULL, *tmp;
288 entry = pmksa->pmksa;
290 if ((entry->network_ctx == network_ctx ||
291 network_ctx == NULL) &&
293 (pmk_len == entry->pmk_len &&
294 os_memcmp(pmk, entry->pmk, pmk_len) == 0))) {
295 wpa_printf(MSG_DEBUG, "RSN: Flush PMKSA cache entry "
296 "for " MACSTR, MAC2STR(entry->aa));
298 prev->next = entry->next;
300 pmksa->pmksa = entry->next;
303 pmksa_cache_free_entry(pmksa, tmp, PMKSA_FREE);
311 pmksa_cache_set_expiration(pmksa);
316 * pmksa_cache_deinit - Free all entries in PMKSA cache
317 * @pmksa: Pointer to PMKSA cache data from pmksa_cache_init()
319 void pmksa_cache_deinit(struct rsn_pmksa_cache *pmksa)
321 struct rsn_pmksa_cache_entry *entry, *prev;
326 entry = pmksa->pmksa;
333 pmksa_cache_set_expiration(pmksa);
339 * pmksa_cache_get - Fetch a PMKSA cache entry
340 * @pmksa: Pointer to PMKSA cache data from pmksa_cache_init()
341 * @aa: Authenticator address or %NULL to match any
342 * @pmkid: PMKID or %NULL to match any
343 * @network_ctx: Network context or %NULL to match any
344 * @akmp: Specific AKMP to search for or 0 for any
345 * Returns: Pointer to PMKSA cache entry or %NULL if no match was found
347 struct rsn_pmksa_cache_entry * pmksa_cache_get(struct rsn_pmksa_cache *pmksa,
348 const u8 *aa, const u8 *pmkid,
349 const void *network_ctx,
352 struct rsn_pmksa_cache_entry *entry = pmksa->pmksa;
354 if ((aa == NULL || os_memcmp(entry->aa, aa, ETH_ALEN) == 0) &&
356 os_memcmp(entry->pmkid, pmkid, PMKID_LEN) == 0) &&
357 (!akmp || akmp == entry->akmp) &&
358 (network_ctx == NULL || network_ctx == entry->network_ctx))
366 static struct rsn_pmksa_cache_entry *
367 pmksa_cache_clone_entry(struct rsn_pmksa_cache *pmksa,
368 const struct rsn_pmksa_cache_entry *old_entry,
371 struct rsn_pmksa_cache_entry *new_entry;
372 os_time_t old_expiration = old_entry->expiration;
374 new_entry = pmksa_cache_add(pmksa, old_entry->pmk, old_entry->pmk_len,
376 aa, pmksa->sm->own_addr,
377 old_entry->network_ctx, old_entry->akmp,
378 old_entry->fils_cache_id_set ?
379 old_entry->fils_cache_id : NULL);
380 if (new_entry == NULL)
383 /* TODO: reorder entries based on expiration time? */
384 new_entry->expiration = old_expiration;
385 new_entry->opportunistic = 1;
392 * pmksa_cache_get_opportunistic - Try to get an opportunistic PMKSA entry
393 * @pmksa: Pointer to PMKSA cache data from pmksa_cache_init()
394 * @network_ctx: Network configuration context
395 * @aa: Authenticator address for the new AP
396 * @akmp: Specific AKMP to search for or 0 for any
397 * Returns: Pointer to a new PMKSA cache entry or %NULL if not available
399 * Try to create a new PMKSA cache entry opportunistically by guessing that the
400 * new AP is sharing the same PMK as another AP that has the same SSID and has
401 * already an entry in PMKSA cache.
403 struct rsn_pmksa_cache_entry *
404 pmksa_cache_get_opportunistic(struct rsn_pmksa_cache *pmksa, void *network_ctx,
405 const u8 *aa, int akmp)
407 struct rsn_pmksa_cache_entry *entry = pmksa->pmksa;
409 wpa_printf(MSG_DEBUG, "RSN: Consider " MACSTR " for OKC", MAC2STR(aa));
410 if (network_ctx == NULL)
413 if (entry->network_ctx == network_ctx &&
414 (!akmp || entry->akmp == akmp)) {
415 entry = pmksa_cache_clone_entry(pmksa, entry, aa);
417 wpa_printf(MSG_DEBUG, "RSN: added "
418 "opportunistic PMKSA cache entry "
419 "for " MACSTR, MAC2STR(aa));
429 static struct rsn_pmksa_cache_entry *
430 pmksa_cache_get_fils_cache_id(struct rsn_pmksa_cache *pmksa,
431 const void *network_ctx, const u8 *cache_id)
433 struct rsn_pmksa_cache_entry *entry;
435 for (entry = pmksa->pmksa; entry; entry = entry->next) {
436 if (network_ctx == entry->network_ctx &&
437 entry->fils_cache_id_set &&
438 os_memcmp(cache_id, entry->fils_cache_id,
439 FILS_CACHE_ID_LEN) == 0)
448 * pmksa_cache_get_current - Get the current used PMKSA entry
449 * @sm: Pointer to WPA state machine data from wpa_sm_init()
450 * Returns: Pointer to the current PMKSA cache entry or %NULL if not available
452 struct rsn_pmksa_cache_entry * pmksa_cache_get_current(struct wpa_sm *sm)
456 return sm->cur_pmksa;
461 * pmksa_cache_clear_current - Clear the current PMKSA entry selection
462 * @sm: Pointer to WPA state machine data from wpa_sm_init()
464 void pmksa_cache_clear_current(struct wpa_sm *sm)
468 sm->cur_pmksa = NULL;
473 * pmksa_cache_set_current - Set the current PMKSA entry selection
474 * @sm: Pointer to WPA state machine data from wpa_sm_init()
475 * @pmkid: PMKID for selecting PMKSA or %NULL if not used
476 * @bssid: BSSID for PMKSA or %NULL if not used
477 * @network_ctx: Network configuration context
478 * @try_opportunistic: Whether to allow opportunistic PMKSA caching
479 * @fils_cache_id: Pointer to FILS Cache Identifier or %NULL if not used
480 * Returns: 0 if PMKSA was found or -1 if no matching entry was found
482 int pmksa_cache_set_current(struct wpa_sm *sm, const u8 *pmkid,
483 const u8 *bssid, void *network_ctx,
484 int try_opportunistic, const u8 *fils_cache_id,
487 struct rsn_pmksa_cache *pmksa = sm->pmksa;
488 wpa_printf(MSG_DEBUG, "RSN: PMKSA cache search - network_ctx=%p "
489 "try_opportunistic=%d akmp=0x%x",
490 network_ctx, try_opportunistic, akmp);
492 wpa_hexdump(MSG_DEBUG, "RSN: Search for PMKID",
495 wpa_printf(MSG_DEBUG, "RSN: Search for BSSID " MACSTR,
498 wpa_printf(MSG_DEBUG,
499 "RSN: Search for FILS Cache Identifier %02x%02x",
500 fils_cache_id[0], fils_cache_id[1]);
502 sm->cur_pmksa = NULL;
504 sm->cur_pmksa = pmksa_cache_get(pmksa, NULL, pmkid,
506 if (sm->cur_pmksa == NULL && bssid)
507 sm->cur_pmksa = pmksa_cache_get(pmksa, bssid, NULL,
509 if (sm->cur_pmksa == NULL && try_opportunistic && bssid)
510 sm->cur_pmksa = pmksa_cache_get_opportunistic(pmksa,
513 if (sm->cur_pmksa == NULL && fils_cache_id)
514 sm->cur_pmksa = pmksa_cache_get_fils_cache_id(pmksa,
518 wpa_hexdump(MSG_DEBUG, "RSN: PMKSA cache entry found - PMKID",
519 sm->cur_pmksa->pmkid, PMKID_LEN);
522 wpa_printf(MSG_DEBUG, "RSN: No PMKSA cache entry found");
528 * pmksa_cache_list - Dump text list of entries in PMKSA cache
529 * @pmksa: Pointer to PMKSA cache data from pmksa_cache_init()
530 * @buf: Buffer for the list
531 * @len: Length of the buffer
532 * Returns: number of bytes written to buffer
534 * This function is used to generate a text format representation of the
535 * current PMKSA cache contents for the ctrl_iface PMKSA command.
537 int pmksa_cache_list(struct rsn_pmksa_cache *pmksa, char *buf, size_t len)
541 struct rsn_pmksa_cache_entry *entry;
542 struct os_reltime now;
543 int cache_id_used = 0;
545 for (entry = pmksa->pmksa; entry; entry = entry->next) {
546 if (entry->fils_cache_id_set) {
552 os_get_reltime(&now);
553 ret = os_snprintf(pos, buf + len - pos,
554 "Index / AA / PMKID / expiration (in seconds) / "
556 cache_id_used ? " / FILS Cache Identifier" : "");
557 if (os_snprintf_error(buf + len - pos, ret))
561 entry = pmksa->pmksa;
564 ret = os_snprintf(pos, buf + len - pos, "%d " MACSTR " ",
565 i, MAC2STR(entry->aa));
566 if (os_snprintf_error(buf + len - pos, ret))
569 pos += wpa_snprintf_hex(pos, buf + len - pos, entry->pmkid,
571 ret = os_snprintf(pos, buf + len - pos, " %d %d",
572 (int) (entry->expiration - now.sec),
573 entry->opportunistic);
574 if (os_snprintf_error(buf + len - pos, ret))
577 if (entry->fils_cache_id_set) {
578 ret = os_snprintf(pos, buf + len - pos, " %02x%02x",
579 entry->fils_cache_id[0],
580 entry->fils_cache_id[1]);
581 if (os_snprintf_error(buf + len - pos, ret))
585 ret = os_snprintf(pos, buf + len - pos, "\n");
586 if (os_snprintf_error(buf + len - pos, ret))
595 struct rsn_pmksa_cache_entry * pmksa_cache_head(struct rsn_pmksa_cache *pmksa)
602 * pmksa_cache_init - Initialize PMKSA cache
603 * @free_cb: Callback function to be called when a PMKSA cache entry is freed
604 * @ctx: Context pointer for free_cb function
605 * @sm: Pointer to WPA state machine data from wpa_sm_init()
606 * Returns: Pointer to PMKSA cache data or %NULL on failure
608 struct rsn_pmksa_cache *
609 pmksa_cache_init(void (*free_cb)(struct rsn_pmksa_cache_entry *entry,
610 void *ctx, enum pmksa_free_reason reason),
611 void *ctx, struct wpa_sm *sm)
613 struct rsn_pmksa_cache *pmksa;
615 pmksa = os_zalloc(sizeof(*pmksa));
617 pmksa->free_cb = free_cb;
625 #endif /* IEEE8021X_EAPOL */