2 * hostapd - PMKSA cache for IEEE 802.11i RSN
3 * Copyright (c) 2004-2008, Jouni Malinen <j@w1.fi>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
9 * Alternatively, this software may be distributed under the terms of BSD
12 * See README and COPYING for more details.
25 #include "pmksa_cache.h"
28 static const int pmksa_cache_max_entries = 1024;
29 static const int dot11RSNAConfigPMKLifetime = 43200;
31 struct rsn_pmksa_cache {
32 #define PMKID_HASH_SIZE 128
33 #define PMKID_HASH(pmkid) (unsigned int) ((pmkid)[0] & 0x7f)
34 struct rsn_pmksa_cache_entry *pmkid[PMKID_HASH_SIZE];
35 struct rsn_pmksa_cache_entry *pmksa;
38 void (*free_cb)(struct rsn_pmksa_cache_entry *entry, void *ctx);
43 static void pmksa_cache_set_expiration(struct rsn_pmksa_cache *pmksa);
46 static void _pmksa_cache_free_entry(struct rsn_pmksa_cache_entry *entry)
50 os_free(entry->identity);
51 radius_free_class(&entry->radius_class);
56 static void pmksa_cache_free_entry(struct rsn_pmksa_cache *pmksa,
57 struct rsn_pmksa_cache_entry *entry)
59 struct rsn_pmksa_cache_entry *pos, *prev;
62 pmksa->free_cb(entry, pmksa->ctx);
63 pos = pmksa->pmkid[PMKID_HASH(entry->pmkid)];
68 prev->hnext = pos->hnext;
70 pmksa->pmkid[PMKID_HASH(entry->pmkid)] =
84 prev->next = pos->next;
86 pmksa->pmksa = pos->next;
92 _pmksa_cache_free_entry(entry);
96 static void pmksa_cache_expire(void *eloop_ctx, void *timeout_ctx)
98 struct rsn_pmksa_cache *pmksa = eloop_ctx;
102 while (pmksa->pmksa && pmksa->pmksa->expiration <= now.sec) {
103 struct rsn_pmksa_cache_entry *entry = pmksa->pmksa;
104 pmksa->pmksa = entry->next;
105 wpa_printf(MSG_DEBUG, "RSN: expired PMKSA cache entry for "
106 MACSTR, MAC2STR(entry->spa));
107 pmksa_cache_free_entry(pmksa, entry);
110 pmksa_cache_set_expiration(pmksa);
114 static void pmksa_cache_set_expiration(struct rsn_pmksa_cache *pmksa)
119 eloop_cancel_timeout(pmksa_cache_expire, pmksa, NULL);
120 if (pmksa->pmksa == NULL)
123 sec = pmksa->pmksa->expiration - now.sec;
126 eloop_register_timeout(sec + 1, 0, pmksa_cache_expire, pmksa, NULL);
130 static void pmksa_cache_from_eapol_data(struct rsn_pmksa_cache_entry *entry,
131 struct eapol_state_machine *eapol)
136 if (eapol->identity) {
137 entry->identity = os_malloc(eapol->identity_len);
138 if (entry->identity) {
139 entry->identity_len = eapol->identity_len;
140 os_memcpy(entry->identity, eapol->identity,
141 eapol->identity_len);
145 radius_copy_class(&entry->radius_class, &eapol->radius_class);
147 entry->eap_type_authsrv = eapol->eap_type_authsrv;
148 entry->vlan_id = eapol->sta->vlan_id;
152 void pmksa_cache_to_eapol_data(struct rsn_pmksa_cache_entry *entry,
153 struct eapol_state_machine *eapol)
155 if (entry == NULL || eapol == NULL)
158 if (entry->identity) {
159 os_free(eapol->identity);
160 eapol->identity = os_malloc(entry->identity_len);
161 if (eapol->identity) {
162 eapol->identity_len = entry->identity_len;
163 os_memcpy(eapol->identity, entry->identity,
164 entry->identity_len);
166 wpa_hexdump_ascii(MSG_DEBUG, "STA identity from PMKSA",
167 eapol->identity, eapol->identity_len);
170 radius_free_class(&eapol->radius_class);
171 radius_copy_class(&eapol->radius_class, &entry->radius_class);
172 if (eapol->radius_class.attr) {
173 wpa_printf(MSG_DEBUG, "Copied %lu Class attribute(s) from "
174 "PMKSA", (unsigned long) eapol->radius_class.count);
177 eapol->eap_type_authsrv = entry->eap_type_authsrv;
178 eapol->sta->vlan_id = entry->vlan_id;
182 static void pmksa_cache_link_entry(struct rsn_pmksa_cache *pmksa,
183 struct rsn_pmksa_cache_entry *entry)
185 struct rsn_pmksa_cache_entry *pos, *prev;
187 /* Add the new entry; order by expiration time */
191 if (pos->expiration > entry->expiration)
197 entry->next = pmksa->pmksa;
198 pmksa->pmksa = entry;
200 entry->next = prev->next;
203 entry->hnext = pmksa->pmkid[PMKID_HASH(entry->pmkid)];
204 pmksa->pmkid[PMKID_HASH(entry->pmkid)] = entry;
206 pmksa->pmksa_count++;
207 wpa_printf(MSG_DEBUG, "RSN: added PMKSA cache entry for " MACSTR,
208 MAC2STR(entry->spa));
209 wpa_hexdump(MSG_DEBUG, "RSN: added PMKID", entry->pmkid, PMKID_LEN);
214 * pmksa_cache_auth_add - Add a PMKSA cache entry
215 * @pmksa: Pointer to PMKSA cache data from pmksa_cache_auth_init()
216 * @pmk: The new pairwise master key
217 * @pmk_len: PMK length in bytes, usually PMK_LEN (32)
218 * @aa: Authenticator address
219 * @spa: Supplicant address
220 * @session_timeout: Session timeout
221 * @eapol: Pointer to EAPOL state machine data
222 * @akmp: WPA_KEY_MGMT_* used in key derivation
223 * Returns: Pointer to the added PMKSA cache entry or %NULL on error
225 * This function create a PMKSA entry for a new PMK and adds it to the PMKSA
226 * cache. If an old entry is already in the cache for the same Supplicant,
227 * this entry will be replaced with the new entry. PMKID will be calculated
230 struct rsn_pmksa_cache_entry *
231 pmksa_cache_auth_add(struct rsn_pmksa_cache *pmksa,
232 const u8 *pmk, size_t pmk_len,
233 const u8 *aa, const u8 *spa, int session_timeout,
234 struct eapol_state_machine *eapol, int akmp)
236 struct rsn_pmksa_cache_entry *entry, *pos;
239 if (pmk_len > PMK_LEN)
242 entry = os_zalloc(sizeof(*entry));
245 os_memcpy(entry->pmk, pmk, pmk_len);
246 entry->pmk_len = pmk_len;
247 rsn_pmkid(pmk, pmk_len, aa, spa, entry->pmkid,
248 wpa_key_mgmt_sha256(akmp));
250 entry->expiration = now.sec;
251 if (session_timeout > 0)
252 entry->expiration += session_timeout;
254 entry->expiration += dot11RSNAConfigPMKLifetime;
256 os_memcpy(entry->spa, spa, ETH_ALEN);
257 pmksa_cache_from_eapol_data(entry, eapol);
259 /* Replace an old entry for the same STA (if found) with the new entry
261 pos = pmksa_cache_auth_get(pmksa, spa, NULL);
263 pmksa_cache_free_entry(pmksa, pos);
265 if (pmksa->pmksa_count >= pmksa_cache_max_entries && pmksa->pmksa) {
266 /* Remove the oldest entry to make room for the new entry */
267 wpa_printf(MSG_DEBUG, "RSN: removed the oldest PMKSA cache "
268 "entry (for " MACSTR ") to make room for new one",
269 MAC2STR(pmksa->pmksa->spa));
270 pmksa_cache_free_entry(pmksa, pmksa->pmksa);
273 pmksa_cache_link_entry(pmksa, entry);
279 struct rsn_pmksa_cache_entry *
280 pmksa_cache_add_okc(struct rsn_pmksa_cache *pmksa,
281 const struct rsn_pmksa_cache_entry *old_entry,
282 const u8 *aa, const u8 *pmkid)
284 struct rsn_pmksa_cache_entry *entry;
286 entry = os_zalloc(sizeof(*entry));
289 os_memcpy(entry->pmkid, pmkid, PMKID_LEN);
290 os_memcpy(entry->pmk, old_entry->pmk, old_entry->pmk_len);
291 entry->pmk_len = old_entry->pmk_len;
292 entry->expiration = old_entry->expiration;
293 entry->akmp = old_entry->akmp;
294 os_memcpy(entry->spa, old_entry->spa, ETH_ALEN);
295 entry->opportunistic = 1;
296 if (old_entry->identity) {
297 entry->identity = os_malloc(old_entry->identity_len);
298 if (entry->identity) {
299 entry->identity_len = old_entry->identity_len;
300 os_memcpy(entry->identity, old_entry->identity,
301 old_entry->identity_len);
304 radius_copy_class(&entry->radius_class, &old_entry->radius_class);
305 entry->eap_type_authsrv = old_entry->eap_type_authsrv;
306 entry->vlan_id = old_entry->vlan_id;
307 entry->opportunistic = 1;
309 pmksa_cache_link_entry(pmksa, entry);
316 * pmksa_cache_auth_deinit - Free all entries in PMKSA cache
317 * @pmksa: Pointer to PMKSA cache data from pmksa_cache_auth_init()
319 void pmksa_cache_auth_deinit(struct rsn_pmksa_cache *pmksa)
321 struct rsn_pmksa_cache_entry *entry, *prev;
327 entry = pmksa->pmksa;
331 _pmksa_cache_free_entry(prev);
333 eloop_cancel_timeout(pmksa_cache_expire, pmksa, NULL);
334 for (i = 0; i < PMKID_HASH_SIZE; i++)
335 pmksa->pmkid[i] = NULL;
341 * pmksa_cache_auth_get - Fetch a PMKSA cache entry
342 * @pmksa: Pointer to PMKSA cache data from pmksa_cache_auth_init()
343 * @spa: Supplicant address or %NULL to match any
344 * @pmkid: PMKID or %NULL to match any
345 * Returns: Pointer to PMKSA cache entry or %NULL if no match was found
347 struct rsn_pmksa_cache_entry *
348 pmksa_cache_auth_get(struct rsn_pmksa_cache *pmksa,
349 const u8 *spa, const u8 *pmkid)
351 struct rsn_pmksa_cache_entry *entry;
354 entry = pmksa->pmkid[PMKID_HASH(pmkid)];
356 entry = pmksa->pmksa;
359 os_memcmp(entry->spa, spa, ETH_ALEN) == 0) &&
361 os_memcmp(entry->pmkid, pmkid, PMKID_LEN) == 0))
363 entry = pmkid ? entry->hnext : entry->next;
370 * pmksa_cache_get_okc - Fetch a PMKSA cache entry using OKC
371 * @pmksa: Pointer to PMKSA cache data from pmksa_cache_auth_init()
372 * @aa: Authenticator address
373 * @spa: Supplicant address
375 * Returns: Pointer to PMKSA cache entry or %NULL if no match was found
377 * Use opportunistic key caching (OKC) to find a PMK for a supplicant.
379 struct rsn_pmksa_cache_entry * pmksa_cache_get_okc(
380 struct rsn_pmksa_cache *pmksa, const u8 *aa, const u8 *spa,
383 struct rsn_pmksa_cache_entry *entry;
384 u8 new_pmkid[PMKID_LEN];
386 entry = pmksa->pmksa;
388 if (os_memcmp(entry->spa, spa, ETH_ALEN) != 0)
390 rsn_pmkid(entry->pmk, entry->pmk_len, aa, spa, new_pmkid,
391 wpa_key_mgmt_sha256(entry->akmp));
392 if (os_memcmp(new_pmkid, pmkid, PMKID_LEN) == 0)
401 * pmksa_cache_auth_init - Initialize PMKSA cache
402 * @free_cb: Callback function to be called when a PMKSA cache entry is freed
403 * @ctx: Context pointer for free_cb function
404 * Returns: Pointer to PMKSA cache data or %NULL on failure
406 struct rsn_pmksa_cache *
407 pmksa_cache_auth_init(void (*free_cb)(struct rsn_pmksa_cache_entry *entry,
408 void *ctx), void *ctx)
410 struct rsn_pmksa_cache *pmksa;
412 pmksa = os_zalloc(sizeof(*pmksa));
414 pmksa->free_cb = free_cb;