Line data Source code
1 : /*
2 : * hostapd - PMKSA cache for IEEE 802.11i RSN
3 : * Copyright (c) 2004-2008, 2012, 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 "sta_info.h"
16 : #include "ap_config.h"
17 : #include "pmksa_cache_auth.h"
18 :
19 :
20 : static const int pmksa_cache_max_entries = 1024;
21 : static const int dot11RSNAConfigPMKLifetime = 43200;
22 :
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;
28 : int pmksa_count;
29 :
30 : void (*free_cb)(struct rsn_pmksa_cache_entry *entry, void *ctx);
31 : void *ctx;
32 : };
33 :
34 :
35 : static void pmksa_cache_set_expiration(struct rsn_pmksa_cache *pmksa);
36 :
37 :
38 273 : static void _pmksa_cache_free_entry(struct rsn_pmksa_cache_entry *entry)
39 : {
40 273 : if (entry == NULL)
41 273 : return;
42 273 : os_free(entry->identity);
43 273 : wpabuf_free(entry->cui);
44 : #ifndef CONFIG_NO_RADIUS
45 273 : radius_free_class(&entry->radius_class);
46 : #endif /* CONFIG_NO_RADIUS */
47 273 : os_free(entry);
48 : }
49 :
50 :
51 101 : 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 :
56 101 : pmksa->pmksa_count--;
57 101 : pmksa->free_cb(entry, pmksa->ctx);
58 101 : pos = pmksa->pmkid[PMKID_HASH(entry->pmkid)];
59 101 : prev = NULL;
60 202 : while (pos) {
61 101 : if (pos == entry) {
62 101 : if (prev != NULL) {
63 0 : prev->hnext = pos->hnext;
64 : } else {
65 202 : pmksa->pmkid[PMKID_HASH(entry->pmkid)] =
66 101 : pos->hnext;
67 : }
68 101 : break;
69 : }
70 0 : prev = pos;
71 0 : pos = pos->hnext;
72 : }
73 :
74 101 : pos = pmksa->pmksa;
75 101 : prev = NULL;
76 206 : while (pos) {
77 105 : if (pos == entry) {
78 101 : if (prev != NULL)
79 4 : prev->next = pos->next;
80 : else
81 97 : pmksa->pmksa = pos->next;
82 101 : break;
83 : }
84 4 : prev = pos;
85 4 : pos = pos->next;
86 : }
87 101 : _pmksa_cache_free_entry(entry);
88 101 : }
89 :
90 :
91 0 : static void pmksa_cache_expire(void *eloop_ctx, void *timeout_ctx)
92 : {
93 0 : struct rsn_pmksa_cache *pmksa = eloop_ctx;
94 : struct os_reltime now;
95 :
96 0 : os_get_reltime(&now);
97 0 : while (pmksa->pmksa && pmksa->pmksa->expiration <= now.sec) {
98 0 : wpa_printf(MSG_DEBUG, "RSN: expired PMKSA cache entry for "
99 0 : MACSTR, MAC2STR(pmksa->pmksa->spa));
100 0 : pmksa_cache_free_entry(pmksa, pmksa->pmksa);
101 : }
102 :
103 0 : pmksa_cache_set_expiration(pmksa);
104 0 : }
105 :
106 :
107 242 : static void pmksa_cache_set_expiration(struct rsn_pmksa_cache *pmksa)
108 : {
109 : int sec;
110 : struct os_reltime now;
111 :
112 242 : eloop_cancel_timeout(pmksa_cache_expire, pmksa, NULL);
113 242 : if (pmksa->pmksa == NULL)
114 242 : return;
115 242 : os_get_reltime(&now);
116 242 : sec = pmksa->pmksa->expiration - now.sec;
117 242 : if (sec < 0)
118 0 : sec = 0;
119 242 : eloop_register_timeout(sec + 1, 0, pmksa_cache_expire, pmksa, NULL);
120 : }
121 :
122 :
123 271 : static void pmksa_cache_from_eapol_data(struct rsn_pmksa_cache_entry *entry,
124 : struct eapol_state_machine *eapol)
125 : {
126 271 : if (eapol == NULL)
127 271 : return;
128 :
129 271 : if (eapol->identity) {
130 240 : entry->identity = os_malloc(eapol->identity_len);
131 240 : if (entry->identity) {
132 240 : entry->identity_len = eapol->identity_len;
133 240 : os_memcpy(entry->identity, eapol->identity,
134 : eapol->identity_len);
135 : }
136 : }
137 :
138 271 : if (eapol->radius_cui)
139 5 : entry->cui = wpabuf_dup(eapol->radius_cui);
140 :
141 : #ifndef CONFIG_NO_RADIUS
142 271 : radius_copy_class(&entry->radius_class, &eapol->radius_class);
143 : #endif /* CONFIG_NO_RADIUS */
144 :
145 271 : entry->eap_type_authsrv = eapol->eap_type_authsrv;
146 271 : entry->vlan_id = ((struct sta_info *) eapol->sta)->vlan_id;
147 : }
148 :
149 :
150 9 : void pmksa_cache_to_eapol_data(struct rsn_pmksa_cache_entry *entry,
151 : struct eapol_state_machine *eapol)
152 : {
153 9 : if (entry == NULL || eapol == NULL)
154 9 : return;
155 :
156 9 : if (entry->identity) {
157 9 : os_free(eapol->identity);
158 9 : eapol->identity = os_malloc(entry->identity_len);
159 9 : if (eapol->identity) {
160 9 : eapol->identity_len = entry->identity_len;
161 9 : os_memcpy(eapol->identity, entry->identity,
162 : entry->identity_len);
163 : }
164 18 : wpa_hexdump_ascii(MSG_DEBUG, "STA identity from PMKSA",
165 9 : eapol->identity, eapol->identity_len);
166 : }
167 :
168 9 : if (entry->cui) {
169 1 : wpabuf_free(eapol->radius_cui);
170 1 : eapol->radius_cui = wpabuf_dup(entry->cui);
171 : }
172 :
173 : #ifndef CONFIG_NO_RADIUS
174 9 : radius_free_class(&eapol->radius_class);
175 9 : radius_copy_class(&eapol->radius_class, &entry->radius_class);
176 : #endif /* CONFIG_NO_RADIUS */
177 9 : if (eapol->radius_class.attr) {
178 1 : wpa_printf(MSG_DEBUG, "Copied %lu Class attribute(s) from "
179 : "PMKSA", (unsigned long) eapol->radius_class.count);
180 : }
181 :
182 9 : eapol->eap_type_authsrv = entry->eap_type_authsrv;
183 9 : ((struct sta_info *) eapol->sta)->vlan_id = entry->vlan_id;
184 : }
185 :
186 :
187 273 : static void pmksa_cache_link_entry(struct rsn_pmksa_cache *pmksa,
188 : struct rsn_pmksa_cache_entry *entry)
189 : {
190 : struct rsn_pmksa_cache_entry *pos, *prev;
191 :
192 : /* Add the new entry; order by expiration time */
193 273 : pos = pmksa->pmksa;
194 273 : prev = NULL;
195 581 : while (pos) {
196 35 : if (pos->expiration > entry->expiration)
197 0 : break;
198 35 : prev = pos;
199 35 : pos = pos->next;
200 : }
201 273 : if (prev == NULL) {
202 242 : entry->next = pmksa->pmksa;
203 242 : pmksa->pmksa = entry;
204 : } else {
205 31 : entry->next = prev->next;
206 31 : prev->next = entry;
207 : }
208 273 : entry->hnext = pmksa->pmkid[PMKID_HASH(entry->pmkid)];
209 273 : pmksa->pmkid[PMKID_HASH(entry->pmkid)] = entry;
210 :
211 273 : pmksa->pmksa_count++;
212 273 : if (prev == NULL)
213 242 : pmksa_cache_set_expiration(pmksa);
214 1638 : wpa_printf(MSG_DEBUG, "RSN: added PMKSA cache entry for " MACSTR,
215 1638 : MAC2STR(entry->spa));
216 273 : wpa_hexdump(MSG_DEBUG, "RSN: added PMKID", entry->pmkid, PMKID_LEN);
217 273 : }
218 :
219 :
220 : /**
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
231 : *
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
235 : * based on the PMK.
236 : */
237 : struct rsn_pmksa_cache_entry *
238 271 : 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)
242 : {
243 : struct rsn_pmksa_cache_entry *entry, *pos;
244 : struct os_reltime now;
245 :
246 271 : if (pmk_len > PMK_LEN)
247 0 : return NULL;
248 :
249 271 : entry = os_zalloc(sizeof(*entry));
250 271 : if (entry == NULL)
251 0 : return NULL;
252 271 : os_memcpy(entry->pmk, pmk, pmk_len);
253 271 : entry->pmk_len = pmk_len;
254 271 : rsn_pmkid(pmk, pmk_len, aa, spa, entry->pmkid,
255 : wpa_key_mgmt_sha256(akmp));
256 271 : os_get_reltime(&now);
257 271 : entry->expiration = now.sec;
258 271 : if (session_timeout > 0)
259 271 : entry->expiration += session_timeout;
260 : else
261 0 : entry->expiration += dot11RSNAConfigPMKLifetime;
262 271 : entry->akmp = akmp;
263 271 : os_memcpy(entry->spa, spa, ETH_ALEN);
264 271 : pmksa_cache_from_eapol_data(entry, eapol);
265 :
266 : /* Replace an old entry for the same STA (if found) with the new entry
267 : */
268 271 : pos = pmksa_cache_auth_get(pmksa, spa, NULL);
269 271 : if (pos)
270 95 : pmksa_cache_free_entry(pmksa, pos);
271 :
272 271 : if (pmksa->pmksa_count >= pmksa_cache_max_entries && pmksa->pmksa) {
273 : /* Remove the oldest entry to make room for the new entry */
274 0 : wpa_printf(MSG_DEBUG, "RSN: removed the oldest PMKSA cache "
275 : "entry (for " MACSTR ") to make room for new one",
276 0 : MAC2STR(pmksa->pmksa->spa));
277 0 : pmksa_cache_free_entry(pmksa, pmksa->pmksa);
278 : }
279 :
280 271 : pmksa_cache_link_entry(pmksa, entry);
281 :
282 271 : return entry;
283 : }
284 :
285 :
286 : struct rsn_pmksa_cache_entry *
287 2 : 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)
290 : {
291 : struct rsn_pmksa_cache_entry *entry;
292 :
293 2 : entry = os_zalloc(sizeof(*entry));
294 2 : if (entry == NULL)
295 0 : return NULL;
296 2 : os_memcpy(entry->pmkid, pmkid, PMKID_LEN);
297 2 : os_memcpy(entry->pmk, old_entry->pmk, old_entry->pmk_len);
298 2 : entry->pmk_len = old_entry->pmk_len;
299 2 : entry->expiration = old_entry->expiration;
300 2 : entry->akmp = old_entry->akmp;
301 2 : os_memcpy(entry->spa, old_entry->spa, ETH_ALEN);
302 2 : entry->opportunistic = 1;
303 2 : if (old_entry->identity) {
304 2 : entry->identity = os_malloc(old_entry->identity_len);
305 2 : if (entry->identity) {
306 2 : entry->identity_len = old_entry->identity_len;
307 2 : os_memcpy(entry->identity, old_entry->identity,
308 : old_entry->identity_len);
309 : }
310 : }
311 2 : if (old_entry->cui)
312 0 : entry->cui = wpabuf_dup(old_entry->cui);
313 : #ifndef CONFIG_NO_RADIUS
314 2 : radius_copy_class(&entry->radius_class, &old_entry->radius_class);
315 : #endif /* CONFIG_NO_RADIUS */
316 2 : entry->eap_type_authsrv = old_entry->eap_type_authsrv;
317 2 : entry->vlan_id = old_entry->vlan_id;
318 2 : entry->opportunistic = 1;
319 :
320 2 : pmksa_cache_link_entry(pmksa, entry);
321 :
322 2 : return entry;
323 : }
324 :
325 :
326 : /**
327 : * pmksa_cache_auth_deinit - Free all entries in PMKSA cache
328 : * @pmksa: Pointer to PMKSA cache data from pmksa_cache_auth_init()
329 : */
330 508 : void pmksa_cache_auth_deinit(struct rsn_pmksa_cache *pmksa)
331 : {
332 : struct rsn_pmksa_cache_entry *entry, *prev;
333 : int i;
334 :
335 508 : if (pmksa == NULL)
336 508 : return;
337 :
338 508 : entry = pmksa->pmksa;
339 1188 : while (entry) {
340 172 : prev = entry;
341 172 : entry = entry->next;
342 172 : _pmksa_cache_free_entry(prev);
343 : }
344 508 : eloop_cancel_timeout(pmksa_cache_expire, pmksa, NULL);
345 65532 : for (i = 0; i < PMKID_HASH_SIZE; i++)
346 65024 : pmksa->pmkid[i] = NULL;
347 508 : os_free(pmksa);
348 : }
349 :
350 :
351 : /**
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
357 : */
358 : struct rsn_pmksa_cache_entry *
359 313 : pmksa_cache_auth_get(struct rsn_pmksa_cache *pmksa,
360 : const u8 *spa, const u8 *pmkid)
361 : {
362 : struct rsn_pmksa_cache_entry *entry;
363 :
364 313 : if (pmkid)
365 35 : entry = pmksa->pmkid[PMKID_HASH(pmkid)];
366 : else
367 278 : entry = pmksa->pmksa;
368 655 : while (entry) {
369 274 : if ((spa == NULL ||
370 245 : os_memcmp(entry->spa, spa, ETH_ALEN) == 0) &&
371 7 : (pmkid == NULL ||
372 7 : os_memcmp(entry->pmkid, pmkid, PMKID_LEN) == 0))
373 108 : return entry;
374 29 : entry = pmkid ? entry->hnext : entry->next;
375 : }
376 205 : return NULL;
377 : }
378 :
379 :
380 : /**
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
385 : * @pmkid: PMKID
386 : * Returns: Pointer to PMKSA cache entry or %NULL if no match was found
387 : *
388 : * Use opportunistic key caching (OKC) to find a PMK for a supplicant.
389 : */
390 2 : struct rsn_pmksa_cache_entry * pmksa_cache_get_okc(
391 : struct rsn_pmksa_cache *pmksa, const u8 *aa, const u8 *spa,
392 : const u8 *pmkid)
393 : {
394 : struct rsn_pmksa_cache_entry *entry;
395 : u8 new_pmkid[PMKID_LEN];
396 :
397 2 : entry = pmksa->pmksa;
398 4 : while (entry) {
399 2 : if (os_memcmp(entry->spa, spa, ETH_ALEN) != 0)
400 0 : continue;
401 2 : rsn_pmkid(entry->pmk, entry->pmk_len, aa, spa, new_pmkid,
402 : wpa_key_mgmt_sha256(entry->akmp));
403 2 : if (os_memcmp(new_pmkid, pmkid, PMKID_LEN) == 0)
404 2 : return entry;
405 0 : entry = entry->next;
406 : }
407 0 : return NULL;
408 : }
409 :
410 :
411 : /**
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
416 : */
417 : struct rsn_pmksa_cache *
418 508 : pmksa_cache_auth_init(void (*free_cb)(struct rsn_pmksa_cache_entry *entry,
419 : void *ctx), void *ctx)
420 : {
421 : struct rsn_pmksa_cache *pmksa;
422 :
423 508 : pmksa = os_zalloc(sizeof(*pmksa));
424 508 : if (pmksa) {
425 508 : pmksa->free_cb = free_cb;
426 508 : pmksa->ctx = ctx;
427 : }
428 :
429 508 : return pmksa;
430 : }
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