2 * hostapd - PMKSA cache for IEEE 802.11i RSN
3 * Copyright (c) 2004-2008, 2012, Jouni Malinen <j@w1.fi>
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
9 #include "utils/includes.h"
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"
16 #include "ap_config.h"
17 #include "pmksa_cache_auth.h"
20 static const int pmksa_cache_max_entries = 1024;
21 static const int dot11RSNAConfigPMKLifetime = 43200;
23 struct rsn_pmksa_cache {
24 #define PMKID_HASH_SIZE 128
25 #define PMKID_HASH(pmkid) (unsigned int) ((pmkid)[0] & 0x7f)
26 struct rsn_pmksa_cache_entry *pmkid[PMKID_HASH_SIZE];
27 struct rsn_pmksa_cache_entry *pmksa;
30 void (*free_cb)(struct rsn_pmksa_cache_entry *entry, void *ctx);
35 static void pmksa_cache_set_expiration(struct rsn_pmksa_cache *pmksa);
38 static void _pmksa_cache_free_entry(struct rsn_pmksa_cache_entry *entry)
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 */
51 static void pmksa_cache_free_entry(struct rsn_pmksa_cache *pmksa,
52 struct rsn_pmksa_cache_entry *entry)
54 struct rsn_pmksa_cache_entry *pos, *prev;
57 pmksa->free_cb(entry, pmksa->ctx);
58 pos = pmksa->pmkid[PMKID_HASH(entry->pmkid)];
63 prev->hnext = pos->hnext;
65 pmksa->pmkid[PMKID_HASH(entry->pmkid)] =
79 prev->next = pos->next;
81 pmksa->pmksa = pos->next;
87 _pmksa_cache_free_entry(entry);
91 static void pmksa_cache_expire(void *eloop_ctx, void *timeout_ctx)
93 struct rsn_pmksa_cache *pmksa = eloop_ctx;
97 while (pmksa->pmksa && pmksa->pmksa->expiration <= now.sec) {
98 wpa_printf(MSG_DEBUG, "RSN: expired PMKSA cache entry for "
99 MACSTR, MAC2STR(pmksa->pmksa->spa));
100 pmksa_cache_free_entry(pmksa, pmksa->pmksa);
103 pmksa_cache_set_expiration(pmksa);
107 static void pmksa_cache_set_expiration(struct rsn_pmksa_cache *pmksa)
112 eloop_cancel_timeout(pmksa_cache_expire, pmksa, NULL);
113 if (pmksa->pmksa == NULL)
116 sec = pmksa->pmksa->expiration - now.sec;
119 eloop_register_timeout(sec + 1, 0, pmksa_cache_expire, pmksa, NULL);
123 static void pmksa_cache_from_eapol_data(struct rsn_pmksa_cache_entry *entry,
124 struct eapol_state_machine *eapol)
129 if (eapol->identity) {
130 entry->identity = os_malloc(eapol->identity_len);
131 if (entry->identity) {
132 entry->identity_len = eapol->identity_len;
133 os_memcpy(entry->identity, eapol->identity,
134 eapol->identity_len);
138 if (eapol->radius_cui)
139 entry->cui = wpabuf_dup(eapol->radius_cui);
141 #ifndef CONFIG_NO_RADIUS
142 radius_copy_class(&entry->radius_class, &eapol->radius_class);
143 #endif /* CONFIG_NO_RADIUS */
145 entry->eap_type_authsrv = eapol->eap_type_authsrv;
146 entry->vlan_id = ((struct sta_info *) eapol->sta)->vlan_id;
150 void pmksa_cache_to_eapol_data(struct rsn_pmksa_cache_entry *entry,
151 struct eapol_state_machine *eapol)
153 if (entry == NULL || eapol == NULL)
156 if (entry->identity) {
157 os_free(eapol->identity);
158 eapol->identity = os_malloc(entry->identity_len);
159 if (eapol->identity) {
160 eapol->identity_len = entry->identity_len;
161 os_memcpy(eapol->identity, entry->identity,
162 entry->identity_len);
164 wpa_hexdump_ascii(MSG_DEBUG, "STA identity from PMKSA",
165 eapol->identity, eapol->identity_len);
169 wpabuf_free(eapol->radius_cui);
170 eapol->radius_cui = wpabuf_dup(entry->cui);
173 #ifndef CONFIG_NO_RADIUS
174 radius_free_class(&eapol->radius_class);
175 radius_copy_class(&eapol->radius_class, &entry->radius_class);
176 #endif /* CONFIG_NO_RADIUS */
177 if (eapol->radius_class.attr) {
178 wpa_printf(MSG_DEBUG, "Copied %lu Class attribute(s) from "
179 "PMKSA", (unsigned long) eapol->radius_class.count);
182 eapol->eap_type_authsrv = entry->eap_type_authsrv;
183 ((struct sta_info *) eapol->sta)->vlan_id = entry->vlan_id;
187 static void pmksa_cache_link_entry(struct rsn_pmksa_cache *pmksa,
188 struct rsn_pmksa_cache_entry *entry)
190 struct rsn_pmksa_cache_entry *pos, *prev;
192 /* Add the new entry; order by expiration time */
196 if (pos->expiration > entry->expiration)
202 entry->next = pmksa->pmksa;
203 pmksa->pmksa = entry;
205 entry->next = prev->next;
208 entry->hnext = pmksa->pmkid[PMKID_HASH(entry->pmkid)];
209 pmksa->pmkid[PMKID_HASH(entry->pmkid)] = entry;
211 pmksa->pmksa_count++;
213 pmksa_cache_set_expiration(pmksa);
214 wpa_printf(MSG_DEBUG, "RSN: added PMKSA cache entry for " MACSTR,
215 MAC2STR(entry->spa));
216 wpa_hexdump(MSG_DEBUG, "RSN: added PMKID", entry->pmkid, PMKID_LEN);
221 * pmksa_cache_auth_add - Add a PMKSA cache entry
222 * @pmksa: Pointer to PMKSA cache data from pmksa_cache_auth_init()
223 * @pmk: The new pairwise master key
224 * @pmk_len: PMK length in bytes, usually PMK_LEN (32)
225 * @aa: Authenticator address
226 * @spa: Supplicant address
227 * @session_timeout: Session timeout
228 * @eapol: Pointer to EAPOL state machine data
229 * @akmp: WPA_KEY_MGMT_* used in key derivation
230 * Returns: Pointer to the added PMKSA cache entry or %NULL on error
232 * This function create a PMKSA entry for a new PMK and adds it to the PMKSA
233 * cache. If an old entry is already in the cache for the same Supplicant,
234 * this entry will be replaced with the new entry. PMKID will be calculated
237 struct rsn_pmksa_cache_entry *
238 pmksa_cache_auth_add(struct rsn_pmksa_cache *pmksa,
239 const u8 *pmk, size_t pmk_len,
240 const u8 *aa, const u8 *spa, int session_timeout,
241 struct eapol_state_machine *eapol, int akmp)
243 struct rsn_pmksa_cache_entry *entry, *pos;
246 if (pmk_len > PMK_LEN)
249 entry = os_zalloc(sizeof(*entry));
252 os_memcpy(entry->pmk, pmk, pmk_len);
253 entry->pmk_len = pmk_len;
254 rsn_pmkid(pmk, pmk_len, aa, spa, entry->pmkid,
255 wpa_key_mgmt_sha256(akmp));
257 entry->expiration = now.sec;
258 if (session_timeout > 0)
259 entry->expiration += session_timeout;
261 entry->expiration += dot11RSNAConfigPMKLifetime;
263 os_memcpy(entry->spa, spa, ETH_ALEN);
264 pmksa_cache_from_eapol_data(entry, eapol);
266 /* Replace an old entry for the same STA (if found) with the new entry
268 pos = pmksa_cache_auth_get(pmksa, spa, NULL);
270 pmksa_cache_free_entry(pmksa, pos);
272 if (pmksa->pmksa_count >= pmksa_cache_max_entries && pmksa->pmksa) {
273 /* Remove the oldest entry to make room for the new entry */
274 wpa_printf(MSG_DEBUG, "RSN: removed the oldest PMKSA cache "
275 "entry (for " MACSTR ") to make room for new one",
276 MAC2STR(pmksa->pmksa->spa));
277 pmksa_cache_free_entry(pmksa, pmksa->pmksa);
280 pmksa_cache_link_entry(pmksa, entry);
286 struct rsn_pmksa_cache_entry *
287 pmksa_cache_add_okc(struct rsn_pmksa_cache *pmksa,
288 const struct rsn_pmksa_cache_entry *old_entry,
289 const u8 *aa, const u8 *pmkid)
291 struct rsn_pmksa_cache_entry *entry;
293 entry = os_zalloc(sizeof(*entry));
296 os_memcpy(entry->pmkid, pmkid, PMKID_LEN);
297 os_memcpy(entry->pmk, old_entry->pmk, old_entry->pmk_len);
298 entry->pmk_len = old_entry->pmk_len;
299 entry->expiration = old_entry->expiration;
300 entry->akmp = old_entry->akmp;
301 os_memcpy(entry->spa, old_entry->spa, ETH_ALEN);
302 entry->opportunistic = 1;
303 if (old_entry->identity) {
304 entry->identity = os_malloc(old_entry->identity_len);
305 if (entry->identity) {
306 entry->identity_len = old_entry->identity_len;
307 os_memcpy(entry->identity, old_entry->identity,
308 old_entry->identity_len);
312 entry->cui = wpabuf_dup(old_entry->cui);
313 #ifndef CONFIG_NO_RADIUS
314 radius_copy_class(&entry->radius_class, &old_entry->radius_class);
315 #endif /* CONFIG_NO_RADIUS */
316 entry->eap_type_authsrv = old_entry->eap_type_authsrv;
317 entry->vlan_id = old_entry->vlan_id;
318 entry->opportunistic = 1;
320 pmksa_cache_link_entry(pmksa, entry);
327 * pmksa_cache_auth_deinit - Free all entries in PMKSA cache
328 * @pmksa: Pointer to PMKSA cache data from pmksa_cache_auth_init()
330 void pmksa_cache_auth_deinit(struct rsn_pmksa_cache *pmksa)
332 struct rsn_pmksa_cache_entry *entry, *prev;
338 entry = pmksa->pmksa;
342 _pmksa_cache_free_entry(prev);
344 eloop_cancel_timeout(pmksa_cache_expire, pmksa, NULL);
345 for (i = 0; i < PMKID_HASH_SIZE; i++)
346 pmksa->pmkid[i] = NULL;
352 * pmksa_cache_auth_get - Fetch a PMKSA cache entry
353 * @pmksa: Pointer to PMKSA cache data from pmksa_cache_auth_init()
354 * @spa: Supplicant address or %NULL to match any
355 * @pmkid: PMKID or %NULL to match any
356 * Returns: Pointer to PMKSA cache entry or %NULL if no match was found
358 struct rsn_pmksa_cache_entry *
359 pmksa_cache_auth_get(struct rsn_pmksa_cache *pmksa,
360 const u8 *spa, const u8 *pmkid)
362 struct rsn_pmksa_cache_entry *entry;
365 entry = pmksa->pmkid[PMKID_HASH(pmkid)];
367 entry = pmksa->pmksa;
370 os_memcmp(entry->spa, spa, ETH_ALEN) == 0) &&
372 os_memcmp(entry->pmkid, pmkid, PMKID_LEN) == 0))
374 entry = pmkid ? entry->hnext : entry->next;
381 * pmksa_cache_get_okc - Fetch a PMKSA cache entry using OKC
382 * @pmksa: Pointer to PMKSA cache data from pmksa_cache_auth_init()
383 * @aa: Authenticator address
384 * @spa: Supplicant address
386 * Returns: Pointer to PMKSA cache entry or %NULL if no match was found
388 * Use opportunistic key caching (OKC) to find a PMK for a supplicant.
390 struct rsn_pmksa_cache_entry * pmksa_cache_get_okc(
391 struct rsn_pmksa_cache *pmksa, const u8 *aa, const u8 *spa,
394 struct rsn_pmksa_cache_entry *entry;
395 u8 new_pmkid[PMKID_LEN];
397 entry = pmksa->pmksa;
399 if (os_memcmp(entry->spa, spa, ETH_ALEN) != 0)
401 rsn_pmkid(entry->pmk, entry->pmk_len, aa, spa, new_pmkid,
402 wpa_key_mgmt_sha256(entry->akmp));
403 if (os_memcmp(new_pmkid, pmkid, PMKID_LEN) == 0)
412 * pmksa_cache_auth_init - Initialize PMKSA cache
413 * @free_cb: Callback function to be called when a PMKSA cache entry is freed
414 * @ctx: Context pointer for free_cb function
415 * Returns: Pointer to PMKSA cache data or %NULL on failure
417 struct rsn_pmksa_cache *
418 pmksa_cache_auth_init(void (*free_cb)(struct rsn_pmksa_cache_entry *entry,
419 void *ctx), void *ctx)
421 struct rsn_pmksa_cache *pmksa;
423 pmksa = os_zalloc(sizeof(*pmksa));
425 pmksa->free_cb = free_cb;