ieee802_11_auth.c revision 04f534e89ed127da4077485376f24debc50d80d5 
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
31struct hostapd_cached_radius_acl {
32	struct os_reltime 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
45struct hostapd_acl_query_data {
46	struct os_reltime 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
56static 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
65static 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
77static 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
100static 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_reltime now;
108
109	os_get_reltime(&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 (os_reltime_expired(&now, &entry->timestamp,
116				       RADIUS_ACL_TIMEOUT))
117			return -1; /* entry has expired */
118		if (entry->accepted == HOSTAPD_ACL_ACCEPT_TIMEOUT)
119			if (session_timeout)
120				*session_timeout = entry->session_timeout;
121		if (acct_interim_interval)
122			*acct_interim_interval =
123				entry->acct_interim_interval;
124		if (vlan_id)
125			*vlan_id = entry->vlan_id;
126		copy_psk_list(psk, entry->psk);
127		if (identity) {
128			if (entry->identity)
129				*identity = os_strdup(entry->identity);
130			else
131				*identity = NULL;
132		}
133		if (radius_cui) {
134			if (entry->radius_cui)
135				*radius_cui = os_strdup(entry->radius_cui);
136			else
137				*radius_cui = NULL;
138		}
139		return entry->accepted;
140	}
141
142	return -1;
143}
144#endif /* CONFIG_NO_RADIUS */
145
146
147static void hostapd_acl_query_free(struct hostapd_acl_query_data *query)
148{
149	if (query == NULL)
150		return;
151	os_free(query->auth_msg);
152	os_free(query);
153}
154
155
156#ifndef CONFIG_NO_RADIUS
157static int hostapd_radius_acl_query(struct hostapd_data *hapd, const u8 *addr,
158				    struct hostapd_acl_query_data *query)
159{
160	struct radius_msg *msg;
161	char buf[128];
162
163	query->radius_id = radius_client_get_id(hapd->radius);
164	msg = radius_msg_new(RADIUS_CODE_ACCESS_REQUEST, query->radius_id);
165	if (msg == NULL)
166		return -1;
167
168	radius_msg_make_authenticator(msg, addr, ETH_ALEN);
169
170	os_snprintf(buf, sizeof(buf), RADIUS_ADDR_FORMAT, MAC2STR(addr));
171	if (!radius_msg_add_attr(msg, RADIUS_ATTR_USER_NAME, (u8 *) buf,
172				 os_strlen(buf))) {
173		wpa_printf(MSG_DEBUG, "Could not add User-Name");
174		goto fail;
175	}
176
177	if (!radius_msg_add_attr_user_password(
178		    msg, (u8 *) buf, os_strlen(buf),
179		    hapd->conf->radius->auth_server->shared_secret,
180		    hapd->conf->radius->auth_server->shared_secret_len)) {
181		wpa_printf(MSG_DEBUG, "Could not add User-Password");
182		goto fail;
183	}
184
185	if (add_common_radius_attr(hapd, hapd->conf->radius_auth_req_attr,
186				   NULL, msg) < 0)
187		goto fail;
188
189	os_snprintf(buf, sizeof(buf), RADIUS_802_1X_ADDR_FORMAT,
190		    MAC2STR(addr));
191	if (!radius_msg_add_attr(msg, RADIUS_ATTR_CALLING_STATION_ID,
192				 (u8 *) buf, os_strlen(buf))) {
193		wpa_printf(MSG_DEBUG, "Could not add Calling-Station-Id");
194		goto fail;
195	}
196
197	os_snprintf(buf, sizeof(buf), "CONNECT 11Mbps 802.11b");
198	if (!radius_msg_add_attr(msg, RADIUS_ATTR_CONNECT_INFO,
199				 (u8 *) buf, os_strlen(buf))) {
200		wpa_printf(MSG_DEBUG, "Could not add Connect-Info");
201		goto fail;
202	}
203
204	if (radius_client_send(hapd->radius, msg, RADIUS_AUTH, addr) < 0)
205		goto fail;
206	return 0;
207
208 fail:
209	radius_msg_free(msg);
210	return -1;
211}
212#endif /* CONFIG_NO_RADIUS */
213
214
215/**
216 * hostapd_allowed_address - Check whether a specified STA can be authenticated
217 * @hapd: hostapd BSS data
218 * @addr: MAC address of the STA
219 * @msg: Authentication message
220 * @len: Length of msg in octets
221 * @session_timeout: Buffer for returning session timeout (from RADIUS)
222 * @acct_interim_interval: Buffer for returning account interval (from RADIUS)
223 * @vlan_id: Buffer for returning VLAN ID
224 * @psk: Linked list buffer for returning WPA PSK
225 * @identity: Buffer for returning identity (from RADIUS)
226 * @radius_cui: Buffer for returning CUI (from RADIUS)
227 * Returns: HOSTAPD_ACL_ACCEPT, HOSTAPD_ACL_REJECT, or HOSTAPD_ACL_PENDING
228 *
229 * The caller is responsible for freeing the returned *identity and *radius_cui
230 * values with os_free().
231 */
232int hostapd_allowed_address(struct hostapd_data *hapd, const u8 *addr,
233			    const u8 *msg, size_t len, u32 *session_timeout,
234			    u32 *acct_interim_interval, int *vlan_id,
235			    struct hostapd_sta_wpa_psk_short **psk,
236			    char **identity, char **radius_cui)
237{
238	if (session_timeout)
239		*session_timeout = 0;
240	if (acct_interim_interval)
241		*acct_interim_interval = 0;
242	if (vlan_id)
243		*vlan_id = 0;
244	if (psk)
245		*psk = NULL;
246	if (identity)
247		*identity = NULL;
248	if (radius_cui)
249		*radius_cui = NULL;
250
251	if (hostapd_maclist_found(hapd->conf->accept_mac,
252				  hapd->conf->num_accept_mac, addr, vlan_id))
253		return HOSTAPD_ACL_ACCEPT;
254
255	if (hostapd_maclist_found(hapd->conf->deny_mac,
256				  hapd->conf->num_deny_mac, addr, vlan_id))
257		return HOSTAPD_ACL_REJECT;
258
259	if (hapd->conf->macaddr_acl == ACCEPT_UNLESS_DENIED)
260		return HOSTAPD_ACL_ACCEPT;
261	if (hapd->conf->macaddr_acl == DENY_UNLESS_ACCEPTED)
262		return HOSTAPD_ACL_REJECT;
263
264	if (hapd->conf->macaddr_acl == USE_EXTERNAL_RADIUS_AUTH) {
265#ifdef CONFIG_NO_RADIUS
266		return HOSTAPD_ACL_REJECT;
267#else /* CONFIG_NO_RADIUS */
268		struct hostapd_acl_query_data *query;
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_reltime(&query->timestamp);
309		os_memcpy(query->addr, addr, ETH_ALEN);
310		if (hostapd_radius_acl_query(hapd, addr, query)) {
311			wpa_printf(MSG_DEBUG, "Failed to send Access-Request "
312				   "for ACL query.");
313			hostapd_acl_query_free(query);
314			return HOSTAPD_ACL_REJECT;
315		}
316
317		query->auth_msg = os_malloc(len);
318		if (query->auth_msg == NULL) {
319			wpa_printf(MSG_ERROR, "Failed to allocate memory for "
320				   "auth frame.");
321			hostapd_acl_query_free(query);
322			return HOSTAPD_ACL_REJECT;
323		}
324		os_memcpy(query->auth_msg, msg, len);
325		query->auth_msg_len = len;
326		query->next = hapd->acl_queries;
327		hapd->acl_queries = query;
328
329		/* Queued data will be processed in hostapd_acl_recv_radius()
330		 * when RADIUS server replies to the sent Access-Request. */
331		return HOSTAPD_ACL_PENDING;
332#endif /* CONFIG_NO_RADIUS */
333	}
334
335	return HOSTAPD_ACL_REJECT;
336}
337
338
339#ifndef CONFIG_NO_RADIUS
340static void hostapd_acl_expire_cache(struct hostapd_data *hapd,
341				     struct os_reltime *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 (os_reltime_expired(now, &entry->timestamp,
350				       RADIUS_ACL_TIMEOUT)) {
351			wpa_printf(MSG_DEBUG, "Cached ACL entry for " MACSTR
352				   " has expired.", MAC2STR(entry->addr));
353			if (prev)
354				prev->next = entry->next;
355			else
356				hapd->acl_cache = entry->next;
357			hostapd_drv_set_radius_acl_expire(hapd, entry->addr);
358			tmp = entry;
359			entry = entry->next;
360			hostapd_acl_cache_free_entry(tmp);
361			continue;
362		}
363
364		prev = entry;
365		entry = entry->next;
366	}
367}
368
369
370static void hostapd_acl_expire_queries(struct hostapd_data *hapd,
371				       struct os_reltime *now)
372{
373	struct hostapd_acl_query_data *prev, *entry, *tmp;
374
375	prev = NULL;
376	entry = hapd->acl_queries;
377
378	while (entry) {
379		if (os_reltime_expired(now, &entry->timestamp,
380				       RADIUS_ACL_TIMEOUT)) {
381			wpa_printf(MSG_DEBUG, "ACL query for " MACSTR
382				   " has expired.", MAC2STR(entry->addr));
383			if (prev)
384				prev->next = entry->next;
385			else
386				hapd->acl_queries = entry->next;
387
388			tmp = entry;
389			entry = entry->next;
390			hostapd_acl_query_free(tmp);
391			continue;
392		}
393
394		prev = entry;
395		entry = entry->next;
396	}
397}
398
399
400/**
401 * hostapd_acl_expire - ACL cache expiration callback
402 * @eloop_ctx: struct hostapd_data *
403 * @timeout_ctx: Not used
404 */
405static void hostapd_acl_expire(void *eloop_ctx, void *timeout_ctx)
406{
407	struct hostapd_data *hapd = eloop_ctx;
408	struct os_reltime now;
409
410	os_get_reltime(&now);
411	hostapd_acl_expire_cache(hapd, &now);
412	hostapd_acl_expire_queries(hapd, &now);
413
414	eloop_register_timeout(10, 0, hostapd_acl_expire, hapd, NULL);
415}
416
417
418static void decode_tunnel_passwords(struct hostapd_data *hapd,
419				    const u8 *shared_secret,
420				    size_t shared_secret_len,
421				    struct radius_msg *msg,
422				    struct radius_msg *req,
423				    struct hostapd_cached_radius_acl *cache)
424{
425	int passphraselen;
426	char *passphrase, *strpassphrase;
427	size_t i;
428	struct hostapd_sta_wpa_psk_short *psk;
429
430	/*
431	 * Decode all tunnel passwords as PSK and save them into a linked list.
432	 */
433	for (i = 0; ; i++) {
434		passphrase = radius_msg_get_tunnel_password(
435			msg, &passphraselen, shared_secret, shared_secret_len,
436			req, i);
437		/*
438		 * Passphrase is NULL iff there is no i-th Tunnel-Password
439		 * attribute in msg.
440		 */
441		if (passphrase == NULL)
442			break;
443		/*
444		 * passphrase does not contain the NULL termination.
445		 * Add it here as pbkdf2_sha1() requires it.
446		 */
447		strpassphrase = os_zalloc(passphraselen + 1);
448		psk = os_zalloc(sizeof(struct hostapd_sta_wpa_psk_short));
449		if (strpassphrase && psk) {
450			os_memcpy(strpassphrase, passphrase, passphraselen);
451			pbkdf2_sha1(strpassphrase,
452				    hapd->conf->ssid.ssid,
453				    hapd->conf->ssid.ssid_len, 4096,
454				    psk->psk, PMK_LEN);
455			psk->next = cache->psk;
456			cache->psk = psk;
457			psk = NULL;
458		}
459		os_free(strpassphrase);
460		os_free(psk);
461		os_free(passphrase);
462	}
463}
464
465
466/**
467 * hostapd_acl_recv_radius - Process incoming RADIUS Authentication messages
468 * @msg: RADIUS response message
469 * @req: RADIUS request message
470 * @shared_secret: RADIUS shared secret
471 * @shared_secret_len: Length of shared_secret in octets
472 * @data: Context data (struct hostapd_data *)
473 * Returns: RADIUS_RX_PROCESSED if RADIUS message was a reply to ACL query (and
474 * was processed here) or RADIUS_RX_UNKNOWN if not.
475 */
476static RadiusRxResult
477hostapd_acl_recv_radius(struct radius_msg *msg, struct radius_msg *req,
478			const u8 *shared_secret, size_t shared_secret_len,
479			void *data)
480{
481	struct hostapd_data *hapd = data;
482	struct hostapd_acl_query_data *query, *prev;
483	struct hostapd_cached_radius_acl *cache;
484	struct radius_hdr *hdr = radius_msg_get_hdr(msg);
485
486	query = hapd->acl_queries;
487	prev = NULL;
488	while (query) {
489		if (query->radius_id == hdr->identifier)
490			break;
491		prev = query;
492		query = query->next;
493	}
494	if (query == NULL)
495		return RADIUS_RX_UNKNOWN;
496
497	wpa_printf(MSG_DEBUG, "Found matching Access-Request for RADIUS "
498		   "message (id=%d)", query->radius_id);
499
500	if (radius_msg_verify(msg, shared_secret, shared_secret_len, req, 0)) {
501		wpa_printf(MSG_INFO, "Incoming RADIUS packet did not have "
502			   "correct authenticator - dropped\n");
503		return RADIUS_RX_INVALID_AUTHENTICATOR;
504	}
505
506	if (hdr->code != RADIUS_CODE_ACCESS_ACCEPT &&
507	    hdr->code != RADIUS_CODE_ACCESS_REJECT) {
508		wpa_printf(MSG_DEBUG, "Unknown RADIUS message code %d to ACL "
509			   "query", hdr->code);
510		return RADIUS_RX_UNKNOWN;
511	}
512
513	/* Insert Accept/Reject info into ACL cache */
514	cache = os_zalloc(sizeof(*cache));
515	if (cache == NULL) {
516		wpa_printf(MSG_DEBUG, "Failed to add ACL cache entry");
517		goto done;
518	}
519	os_get_reltime(&cache->timestamp);
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 */
599int 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 */
617void 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
636void 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}
644