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[FreeBSD/releng/10.2.git] / contrib / wpa / src / ap / ieee802_11_auth.c
1 /*
2  * hostapd / IEEE 802.11 authentication (ACL)
3  * Copyright (c) 2003-2012, 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  * Access control list for IEEE 802.11 authentication can uses statically
9  * configured ACL from configuration files or an external RADIUS server.
10  * Results from external RADIUS queries are cached to allow faster
11  * authentication frame processing.
12  */
13
14 #include "utils/includes.h"
15
16 #include "utils/common.h"
17 #include "utils/eloop.h"
18 #include "crypto/sha1.h"
19 #include "radius/radius.h"
20 #include "radius/radius_client.h"
21 #include "hostapd.h"
22 #include "ap_config.h"
23 #include "ap_drv_ops.h"
24 #include "ieee802_11.h"
25 #include "ieee802_1x.h"
26 #include "ieee802_11_auth.h"
27
28 #define RADIUS_ACL_TIMEOUT 30
29
30
31 struct hostapd_cached_radius_acl {
32         os_time_t timestamp;
33         macaddr addr;
34         int accepted; /* HOSTAPD_ACL_* */
35         struct hostapd_cached_radius_acl *next;
36         u32 session_timeout;
37         u32 acct_interim_interval;
38         int vlan_id;
39         struct hostapd_sta_wpa_psk_short *psk;
40         char *identity;
41         char *radius_cui;
42 };
43
44
45 struct hostapd_acl_query_data {
46         os_time_t timestamp;
47         u8 radius_id;
48         macaddr addr;
49         u8 *auth_msg; /* IEEE 802.11 authentication frame from station */
50         size_t auth_msg_len;
51         struct hostapd_acl_query_data *next;
52 };
53
54
55 #ifndef CONFIG_NO_RADIUS
56 static void hostapd_acl_cache_free_entry(struct hostapd_cached_radius_acl *e)
57 {
58         os_free(e->identity);
59         os_free(e->radius_cui);
60         hostapd_free_psk_list(e->psk);
61         os_free(e);
62 }
63
64
65 static void hostapd_acl_cache_free(struct hostapd_cached_radius_acl *acl_cache)
66 {
67         struct hostapd_cached_radius_acl *prev;
68
69         while (acl_cache) {
70                 prev = acl_cache;
71                 acl_cache = acl_cache->next;
72                 hostapd_acl_cache_free_entry(prev);
73         }
74 }
75
76
77 static void copy_psk_list(struct hostapd_sta_wpa_psk_short **psk,
78                           struct hostapd_sta_wpa_psk_short *src)
79 {
80         struct hostapd_sta_wpa_psk_short **copy_to;
81         struct hostapd_sta_wpa_psk_short *copy_from;
82
83         /* Copy PSK linked list */
84         copy_to = psk;
85         copy_from = src;
86         while (copy_from && copy_to) {
87                 *copy_to = os_zalloc(sizeof(struct hostapd_sta_wpa_psk_short));
88                 if (*copy_to == NULL)
89                         break;
90                 os_memcpy(*copy_to, copy_from,
91                           sizeof(struct hostapd_sta_wpa_psk_short));
92                 copy_from = copy_from->next;
93                 copy_to = &((*copy_to)->next);
94         }
95         if (copy_to)
96                 *copy_to = NULL;
97 }
98
99
100 static int hostapd_acl_cache_get(struct hostapd_data *hapd, const u8 *addr,
101                                  u32 *session_timeout,
102                                  u32 *acct_interim_interval, int *vlan_id,
103                                  struct hostapd_sta_wpa_psk_short **psk,
104                                  char **identity, char **radius_cui)
105 {
106         struct hostapd_cached_radius_acl *entry;
107         struct os_time now;
108
109         os_get_time(&now);
110
111         for (entry = hapd->acl_cache; entry; entry = entry->next) {
112                 if (os_memcmp(entry->addr, addr, ETH_ALEN) != 0)
113                         continue;
114
115                 if (now.sec - entry->timestamp > RADIUS_ACL_TIMEOUT)
116                         return -1; /* entry has expired */
117                 if (entry->accepted == HOSTAPD_ACL_ACCEPT_TIMEOUT)
118                         if (session_timeout)
119                                 *session_timeout = entry->session_timeout;
120                 if (acct_interim_interval)
121                         *acct_interim_interval =
122                                 entry->acct_interim_interval;
123                 if (vlan_id)
124                         *vlan_id = entry->vlan_id;
125                 copy_psk_list(psk, entry->psk);
126                 if (identity) {
127                         if (entry->identity)
128                                 *identity = os_strdup(entry->identity);
129                         else
130                                 *identity = NULL;
131                 }
132                 if (radius_cui) {
133                         if (entry->radius_cui)
134                                 *radius_cui = os_strdup(entry->radius_cui);
135                         else
136                                 *radius_cui = NULL;
137                 }
138                 return entry->accepted;
139         }
140
141         return -1;
142 }
143 #endif /* CONFIG_NO_RADIUS */
144
145
146 static void hostapd_acl_query_free(struct hostapd_acl_query_data *query)
147 {
148         if (query == NULL)
149                 return;
150         os_free(query->auth_msg);
151         os_free(query);
152 }
153
154
155 #ifndef CONFIG_NO_RADIUS
156 static int hostapd_radius_acl_query(struct hostapd_data *hapd, const u8 *addr,
157                                     struct hostapd_acl_query_data *query)
158 {
159         struct radius_msg *msg;
160         char buf[128];
161
162         query->radius_id = radius_client_get_id(hapd->radius);
163         msg = radius_msg_new(RADIUS_CODE_ACCESS_REQUEST, query->radius_id);
164         if (msg == NULL)
165                 return -1;
166
167         radius_msg_make_authenticator(msg, addr, ETH_ALEN);
168
169         os_snprintf(buf, sizeof(buf), RADIUS_ADDR_FORMAT, MAC2STR(addr));
170         if (!radius_msg_add_attr(msg, RADIUS_ATTR_USER_NAME, (u8 *) buf,
171                                  os_strlen(buf))) {
172                 wpa_printf(MSG_DEBUG, "Could not add User-Name");
173                 goto fail;
174         }
175
176         if (!radius_msg_add_attr_user_password(
177                     msg, (u8 *) buf, os_strlen(buf),
178                     hapd->conf->radius->auth_server->shared_secret,
179                     hapd->conf->radius->auth_server->shared_secret_len)) {
180                 wpa_printf(MSG_DEBUG, "Could not add User-Password");
181                 goto fail;
182         }
183
184         if (add_common_radius_attr(hapd, hapd->conf->radius_auth_req_attr,
185                                    NULL, msg) < 0)
186                 goto fail;
187
188         os_snprintf(buf, sizeof(buf), RADIUS_802_1X_ADDR_FORMAT,
189                     MAC2STR(addr));
190         if (!radius_msg_add_attr(msg, RADIUS_ATTR_CALLING_STATION_ID,
191                                  (u8 *) buf, os_strlen(buf))) {
192                 wpa_printf(MSG_DEBUG, "Could not add Calling-Station-Id");
193                 goto fail;
194         }
195
196         os_snprintf(buf, sizeof(buf), "CONNECT 11Mbps 802.11b");
197         if (!radius_msg_add_attr(msg, RADIUS_ATTR_CONNECT_INFO,
198                                  (u8 *) buf, os_strlen(buf))) {
199                 wpa_printf(MSG_DEBUG, "Could not add Connect-Info");
200                 goto fail;
201         }
202
203         if (radius_client_send(hapd->radius, msg, RADIUS_AUTH, addr) < 0)
204                 goto fail;
205         return 0;
206
207  fail:
208         radius_msg_free(msg);
209         return -1;
210 }
211 #endif /* CONFIG_NO_RADIUS */
212
213
214 /**
215  * hostapd_allowed_address - Check whether a specified STA can be authenticated
216  * @hapd: hostapd BSS data
217  * @addr: MAC address of the STA
218  * @msg: Authentication message
219  * @len: Length of msg in octets
220  * @session_timeout: Buffer for returning session timeout (from RADIUS)
221  * @acct_interim_interval: Buffer for returning account interval (from RADIUS)
222  * @vlan_id: Buffer for returning VLAN ID
223  * @psk: Linked list buffer for returning WPA PSK
224  * @identity: Buffer for returning identity (from RADIUS)
225  * @radius_cui: Buffer for returning CUI (from RADIUS)
226  * Returns: HOSTAPD_ACL_ACCEPT, HOSTAPD_ACL_REJECT, or HOSTAPD_ACL_PENDING
227  *
228  * The caller is responsible for freeing the returned *identity and *radius_cui
229  * values with os_free().
230  */
231 int hostapd_allowed_address(struct hostapd_data *hapd, const u8 *addr,
232                             const u8 *msg, size_t len, u32 *session_timeout,
233                             u32 *acct_interim_interval, int *vlan_id,
234                             struct hostapd_sta_wpa_psk_short **psk,
235                             char **identity, char **radius_cui)
236 {
237         if (session_timeout)
238                 *session_timeout = 0;
239         if (acct_interim_interval)
240                 *acct_interim_interval = 0;
241         if (vlan_id)
242                 *vlan_id = 0;
243         if (psk)
244                 *psk = NULL;
245         if (identity)
246                 *identity = NULL;
247         if (radius_cui)
248                 *radius_cui = NULL;
249
250         if (hostapd_maclist_found(hapd->conf->accept_mac,
251                                   hapd->conf->num_accept_mac, addr, vlan_id))
252                 return HOSTAPD_ACL_ACCEPT;
253
254         if (hostapd_maclist_found(hapd->conf->deny_mac,
255                                   hapd->conf->num_deny_mac, addr, vlan_id))
256                 return HOSTAPD_ACL_REJECT;
257
258         if (hapd->conf->macaddr_acl == ACCEPT_UNLESS_DENIED)
259                 return HOSTAPD_ACL_ACCEPT;
260         if (hapd->conf->macaddr_acl == DENY_UNLESS_ACCEPTED)
261                 return HOSTAPD_ACL_REJECT;
262
263         if (hapd->conf->macaddr_acl == USE_EXTERNAL_RADIUS_AUTH) {
264 #ifdef CONFIG_NO_RADIUS
265                 return HOSTAPD_ACL_REJECT;
266 #else /* CONFIG_NO_RADIUS */
267                 struct hostapd_acl_query_data *query;
268                 struct os_time t;
269
270                 /* Check whether ACL cache has an entry for this station */
271                 int res = hostapd_acl_cache_get(hapd, addr, session_timeout,
272                                                 acct_interim_interval,
273                                                 vlan_id, psk,
274                                                 identity, radius_cui);
275                 if (res == HOSTAPD_ACL_ACCEPT ||
276                     res == HOSTAPD_ACL_ACCEPT_TIMEOUT)
277                         return res;
278                 if (res == HOSTAPD_ACL_REJECT)
279                         return HOSTAPD_ACL_REJECT;
280
281                 query = hapd->acl_queries;
282                 while (query) {
283                         if (os_memcmp(query->addr, addr, ETH_ALEN) == 0) {
284                                 /* pending query in RADIUS retransmit queue;
285                                  * do not generate a new one */
286                                 if (identity) {
287                                         os_free(*identity);
288                                         *identity = NULL;
289                                 }
290                                 if (radius_cui) {
291                                         os_free(*radius_cui);
292                                         *radius_cui = NULL;
293                                 }
294                                 return HOSTAPD_ACL_PENDING;
295                         }
296                         query = query->next;
297                 }
298
299                 if (!hapd->conf->radius->auth_server)
300                         return HOSTAPD_ACL_REJECT;
301
302                 /* No entry in the cache - query external RADIUS server */
303                 query = os_zalloc(sizeof(*query));
304                 if (query == NULL) {
305                         wpa_printf(MSG_ERROR, "malloc for query data failed");
306                         return HOSTAPD_ACL_REJECT;
307                 }
308                 os_get_time(&t);
309                 query->timestamp = t.sec;
310                 os_memcpy(query->addr, addr, ETH_ALEN);
311                 if (hostapd_radius_acl_query(hapd, addr, query)) {
312                         wpa_printf(MSG_DEBUG, "Failed to send Access-Request "
313                                    "for ACL query.");
314                         hostapd_acl_query_free(query);
315                         return HOSTAPD_ACL_REJECT;
316                 }
317
318                 query->auth_msg = os_malloc(len);
319                 if (query->auth_msg == NULL) {
320                         wpa_printf(MSG_ERROR, "Failed to allocate memory for "
321                                    "auth frame.");
322                         hostapd_acl_query_free(query);
323                         return HOSTAPD_ACL_REJECT;
324                 }
325                 os_memcpy(query->auth_msg, msg, len);
326                 query->auth_msg_len = len;
327                 query->next = hapd->acl_queries;
328                 hapd->acl_queries = query;
329
330                 /* Queued data will be processed in hostapd_acl_recv_radius()
331                  * when RADIUS server replies to the sent Access-Request. */
332                 return HOSTAPD_ACL_PENDING;
333 #endif /* CONFIG_NO_RADIUS */
334         }
335
336         return HOSTAPD_ACL_REJECT;
337 }
338
339
340 #ifndef CONFIG_NO_RADIUS
341 static void hostapd_acl_expire_cache(struct hostapd_data *hapd, os_time_t now)
342 {
343         struct hostapd_cached_radius_acl *prev, *entry, *tmp;
344
345         prev = NULL;
346         entry = hapd->acl_cache;
347
348         while (entry) {
349                 if (now - entry->timestamp > RADIUS_ACL_TIMEOUT) {
350                         wpa_printf(MSG_DEBUG, "Cached ACL entry for " MACSTR
351                                    " has expired.", MAC2STR(entry->addr));
352                         if (prev)
353                                 prev->next = entry->next;
354                         else
355                                 hapd->acl_cache = entry->next;
356                         hostapd_drv_set_radius_acl_expire(hapd, entry->addr);
357                         tmp = entry;
358                         entry = entry->next;
359                         hostapd_acl_cache_free_entry(tmp);
360                         continue;
361                 }
362
363                 prev = entry;
364                 entry = entry->next;
365         }
366 }
367
368
369 static void hostapd_acl_expire_queries(struct hostapd_data *hapd,
370                                        os_time_t now)
371 {
372         struct hostapd_acl_query_data *prev, *entry, *tmp;
373
374         prev = NULL;
375         entry = hapd->acl_queries;
376
377         while (entry) {
378                 if (now - entry->timestamp > RADIUS_ACL_TIMEOUT) {
379                         wpa_printf(MSG_DEBUG, "ACL query for " MACSTR
380                                    " has expired.", MAC2STR(entry->addr));
381                         if (prev)
382                                 prev->next = entry->next;
383                         else
384                                 hapd->acl_queries = entry->next;
385
386                         tmp = entry;
387                         entry = entry->next;
388                         hostapd_acl_query_free(tmp);
389                         continue;
390                 }
391
392                 prev = entry;
393                 entry = entry->next;
394         }
395 }
396
397
398 /**
399  * hostapd_acl_expire - ACL cache expiration callback
400  * @eloop_ctx: struct hostapd_data *
401  * @timeout_ctx: Not used
402  */
403 static void hostapd_acl_expire(void *eloop_ctx, void *timeout_ctx)
404 {
405         struct hostapd_data *hapd = eloop_ctx;
406         struct os_time now;
407
408         os_get_time(&now);
409         hostapd_acl_expire_cache(hapd, now.sec);
410         hostapd_acl_expire_queries(hapd, now.sec);
411
412         eloop_register_timeout(10, 0, hostapd_acl_expire, hapd, NULL);
413 }
414
415
416 static void decode_tunnel_passwords(struct hostapd_data *hapd,
417                                     const u8 *shared_secret,
418                                     size_t shared_secret_len,
419                                     struct radius_msg *msg,
420                                     struct radius_msg *req,
421                                     struct hostapd_cached_radius_acl *cache)
422 {
423         int passphraselen;
424         char *passphrase, *strpassphrase;
425         size_t i;
426         struct hostapd_sta_wpa_psk_short *psk;
427
428         /*
429          * Decode all tunnel passwords as PSK and save them into a linked list.
430          */
431         for (i = 0; ; i++) {
432                 passphrase = radius_msg_get_tunnel_password(
433                         msg, &passphraselen, shared_secret, shared_secret_len,
434                         req, i);
435                 /*
436                  * Passphrase is NULL iff there is no i-th Tunnel-Password
437                  * attribute in msg.
438                  */
439                 if (passphrase == NULL)
440                         break;
441                 /*
442                  * passphrase does not contain the NULL termination.
443                  * Add it here as pbkdf2_sha1() requires it.
444                  */
445                 strpassphrase = os_zalloc(passphraselen + 1);
446                 psk = os_zalloc(sizeof(struct hostapd_sta_wpa_psk_short));
447                 if (strpassphrase && psk) {
448                         os_memcpy(strpassphrase, passphrase, passphraselen);
449                         pbkdf2_sha1(strpassphrase,
450                                     hapd->conf->ssid.ssid,
451                                     hapd->conf->ssid.ssid_len, 4096,
452                                     psk->psk, PMK_LEN);
453                         psk->next = cache->psk;
454                         cache->psk = psk;
455                         psk = NULL;
456                 }
457                 os_free(strpassphrase);
458                 os_free(psk);
459                 os_free(passphrase);
460         }
461 }
462
463
464 /**
465  * hostapd_acl_recv_radius - Process incoming RADIUS Authentication messages
466  * @msg: RADIUS response message
467  * @req: RADIUS request message
468  * @shared_secret: RADIUS shared secret
469  * @shared_secret_len: Length of shared_secret in octets
470  * @data: Context data (struct hostapd_data *)
471  * Returns: RADIUS_RX_PROCESSED if RADIUS message was a reply to ACL query (and
472  * was processed here) or RADIUS_RX_UNKNOWN if not.
473  */
474 static RadiusRxResult
475 hostapd_acl_recv_radius(struct radius_msg *msg, struct radius_msg *req,
476                         const u8 *shared_secret, size_t shared_secret_len,
477                         void *data)
478 {
479         struct hostapd_data *hapd = data;
480         struct hostapd_acl_query_data *query, *prev;
481         struct hostapd_cached_radius_acl *cache;
482         struct radius_hdr *hdr = radius_msg_get_hdr(msg);
483         struct os_time t;
484
485         query = hapd->acl_queries;
486         prev = NULL;
487         while (query) {
488                 if (query->radius_id == hdr->identifier)
489                         break;
490                 prev = query;
491                 query = query->next;
492         }
493         if (query == NULL)
494                 return RADIUS_RX_UNKNOWN;
495
496         wpa_printf(MSG_DEBUG, "Found matching Access-Request for RADIUS "
497                    "message (id=%d)", query->radius_id);
498
499         if (radius_msg_verify(msg, shared_secret, shared_secret_len, req, 0)) {
500                 wpa_printf(MSG_INFO, "Incoming RADIUS packet did not have "
501                            "correct authenticator - dropped\n");
502                 return RADIUS_RX_INVALID_AUTHENTICATOR;
503         }
504
505         if (hdr->code != RADIUS_CODE_ACCESS_ACCEPT &&
506             hdr->code != RADIUS_CODE_ACCESS_REJECT) {
507                 wpa_printf(MSG_DEBUG, "Unknown RADIUS message code %d to ACL "
508                            "query", hdr->code);
509                 return RADIUS_RX_UNKNOWN;
510         }
511
512         /* Insert Accept/Reject info into ACL cache */
513         cache = os_zalloc(sizeof(*cache));
514         if (cache == NULL) {
515                 wpa_printf(MSG_DEBUG, "Failed to add ACL cache entry");
516                 goto done;
517         }
518         os_get_time(&t);
519         cache->timestamp = t.sec;
520         os_memcpy(cache->addr, query->addr, sizeof(cache->addr));
521         if (hdr->code == RADIUS_CODE_ACCESS_ACCEPT) {
522                 u8 *buf;
523                 size_t len;
524
525                 if (radius_msg_get_attr_int32(msg, RADIUS_ATTR_SESSION_TIMEOUT,
526                                               &cache->session_timeout) == 0)
527                         cache->accepted = HOSTAPD_ACL_ACCEPT_TIMEOUT;
528                 else
529                         cache->accepted = HOSTAPD_ACL_ACCEPT;
530
531                 if (radius_msg_get_attr_int32(
532                             msg, RADIUS_ATTR_ACCT_INTERIM_INTERVAL,
533                             &cache->acct_interim_interval) == 0 &&
534                     cache->acct_interim_interval < 60) {
535                         wpa_printf(MSG_DEBUG, "Ignored too small "
536                                    "Acct-Interim-Interval %d for STA " MACSTR,
537                                    cache->acct_interim_interval,
538                                    MAC2STR(query->addr));
539                         cache->acct_interim_interval = 0;
540                 }
541
542                 cache->vlan_id = radius_msg_get_vlanid(msg);
543
544                 decode_tunnel_passwords(hapd, shared_secret, shared_secret_len,
545                                         msg, req, cache);
546
547                 if (radius_msg_get_attr_ptr(msg, RADIUS_ATTR_USER_NAME,
548                                             &buf, &len, NULL) == 0) {
549                         cache->identity = os_zalloc(len + 1);
550                         if (cache->identity)
551                                 os_memcpy(cache->identity, buf, len);
552                 }
553                 if (radius_msg_get_attr_ptr(
554                             msg, RADIUS_ATTR_CHARGEABLE_USER_IDENTITY,
555                             &buf, &len, NULL) == 0) {
556                         cache->radius_cui = os_zalloc(len + 1);
557                         if (cache->radius_cui)
558                                 os_memcpy(cache->radius_cui, buf, len);
559                 }
560
561                 if (hapd->conf->wpa_psk_radius == PSK_RADIUS_REQUIRED &&
562                     !cache->psk)
563                         cache->accepted = HOSTAPD_ACL_REJECT;
564         } else
565                 cache->accepted = HOSTAPD_ACL_REJECT;
566         cache->next = hapd->acl_cache;
567         hapd->acl_cache = cache;
568
569 #ifdef CONFIG_DRIVER_RADIUS_ACL
570         hostapd_drv_set_radius_acl_auth(hapd, query->addr, cache->accepted,
571                                         cache->session_timeout);
572 #else /* CONFIG_DRIVER_RADIUS_ACL */
573 #ifdef NEED_AP_MLME
574         /* Re-send original authentication frame for 802.11 processing */
575         wpa_printf(MSG_DEBUG, "Re-sending authentication frame after "
576                    "successful RADIUS ACL query");
577         ieee802_11_mgmt(hapd, query->auth_msg, query->auth_msg_len, NULL);
578 #endif /* NEED_AP_MLME */
579 #endif /* CONFIG_DRIVER_RADIUS_ACL */
580
581  done:
582         if (prev == NULL)
583                 hapd->acl_queries = query->next;
584         else
585                 prev->next = query->next;
586
587         hostapd_acl_query_free(query);
588
589         return RADIUS_RX_PROCESSED;
590 }
591 #endif /* CONFIG_NO_RADIUS */
592
593
594 /**
595  * hostapd_acl_init: Initialize IEEE 802.11 ACL
596  * @hapd: hostapd BSS data
597  * Returns: 0 on success, -1 on failure
598  */
599 int hostapd_acl_init(struct hostapd_data *hapd)
600 {
601 #ifndef CONFIG_NO_RADIUS
602         if (radius_client_register(hapd->radius, RADIUS_AUTH,
603                                    hostapd_acl_recv_radius, hapd))
604                 return -1;
605
606         eloop_register_timeout(10, 0, hostapd_acl_expire, hapd, NULL);
607 #endif /* CONFIG_NO_RADIUS */
608
609         return 0;
610 }
611
612
613 /**
614  * hostapd_acl_deinit - Deinitialize IEEE 802.11 ACL
615  * @hapd: hostapd BSS data
616  */
617 void hostapd_acl_deinit(struct hostapd_data *hapd)
618 {
619         struct hostapd_acl_query_data *query, *prev;
620
621 #ifndef CONFIG_NO_RADIUS
622         eloop_cancel_timeout(hostapd_acl_expire, hapd, NULL);
623
624         hostapd_acl_cache_free(hapd->acl_cache);
625 #endif /* CONFIG_NO_RADIUS */
626
627         query = hapd->acl_queries;
628         while (query) {
629                 prev = query;
630                 query = query->next;
631                 hostapd_acl_query_free(prev);
632         }
633 }
634
635
636 void hostapd_free_psk_list(struct hostapd_sta_wpa_psk_short *psk)
637 {
638         while (psk) {
639                 struct hostapd_sta_wpa_psk_short *prev = psk;
640                 psk = psk->next;
641                 os_free(prev);
642         }
643 }