ibss_rsn.c revision 8d520ff1dc2da35cdca849e982051b86468016d8 
1/*
2 * wpa_supplicant - IBSS RSN
3 * Copyright (c) 2009, Jouni Malinen <j@w1.fi>
4 *
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.
8 *
9 * Alternatively, this software may be distributed under the terms of BSD
10 * license.
11 *
12 * See README and COPYING for more details.
13 */
14
15#include "includes.h"
16
17#include "common.h"
18#include "l2_packet/l2_packet.h"
19#include "rsn_supp/wpa.h"
20#include "rsn_supp/wpa_ie.h"
21#include "ap/wpa_auth.h"
22#include "wpa_supplicant_i.h"
23#include "driver_i.h"
24#include "ibss_rsn.h"
25
26
27static void ibss_rsn_free(struct ibss_rsn_peer *peer)
28{
29	wpa_auth_sta_deinit(peer->auth);
30	wpa_sm_deinit(peer->supp);
31	os_free(peer);
32}
33
34
35static void supp_set_state(void *ctx, enum wpa_states state)
36{
37	struct ibss_rsn_peer *peer = ctx;
38	peer->supp_state = state;
39}
40
41
42static enum wpa_states supp_get_state(void *ctx)
43{
44	struct ibss_rsn_peer *peer = ctx;
45	return peer->supp_state;
46}
47
48
49static int supp_ether_send(void *ctx, const u8 *dest, u16 proto, const u8 *buf,
50			   size_t len)
51{
52	struct ibss_rsn_peer *peer = ctx;
53	struct wpa_supplicant *wpa_s = peer->ibss_rsn->wpa_s;
54
55	wpa_printf(MSG_DEBUG, "SUPP: %s(dest=" MACSTR " proto=0x%04x "
56		   "len=%lu)",
57		   __func__, MAC2STR(dest), proto, (unsigned long) len);
58
59	if (wpa_s->l2)
60		return l2_packet_send(wpa_s->l2, dest, proto, buf, len);
61
62	return wpa_drv_send_eapol(wpa_s, dest, proto, buf, len);
63}
64
65
66static u8 * supp_alloc_eapol(void *ctx, u8 type, const void *data,
67			     u16 data_len, size_t *msg_len, void **data_pos)
68{
69	struct ieee802_1x_hdr *hdr;
70
71	wpa_printf(MSG_DEBUG, "SUPP: %s(type=%d data_len=%d)",
72		   __func__, type, data_len);
73
74	*msg_len = sizeof(*hdr) + data_len;
75	hdr = os_malloc(*msg_len);
76	if (hdr == NULL)
77		return NULL;
78
79	hdr->version = 2;
80	hdr->type = type;
81	hdr->length = host_to_be16(data_len);
82
83	if (data)
84		os_memcpy(hdr + 1, data, data_len);
85	else
86		os_memset(hdr + 1, 0, data_len);
87
88	if (data_pos)
89		*data_pos = hdr + 1;
90
91	return (u8 *) hdr;
92}
93
94
95static int supp_get_beacon_ie(void *ctx)
96{
97	struct ibss_rsn_peer *peer = ctx;
98
99	wpa_printf(MSG_DEBUG, "SUPP: %s", __func__);
100	/* TODO: get correct RSN IE */
101	return wpa_sm_set_ap_rsn_ie(peer->supp,
102				    (u8 *) "\x30\x14\x01\x00"
103				    "\x00\x0f\xac\x04"
104				    "\x01\x00\x00\x0f\xac\x04"
105				    "\x01\x00\x00\x0f\xac\x02"
106				    "\x00\x00", 22);
107}
108
109
110static int supp_set_key(void *ctx, enum wpa_alg alg,
111			const u8 *addr, int key_idx, int set_tx,
112			const u8 *seq, size_t seq_len,
113			const u8 *key, size_t key_len)
114{
115	struct ibss_rsn_peer *peer = ctx;
116
117	wpa_printf(MSG_DEBUG, "SUPP: %s(alg=%d addr=" MACSTR " key_idx=%d "
118		   "set_tx=%d)",
119		   __func__, alg, MAC2STR(addr), key_idx, set_tx);
120	wpa_hexdump(MSG_DEBUG, "SUPP: set_key - seq", seq, seq_len);
121	wpa_hexdump_key(MSG_DEBUG, "SUPP: set_key - key", key, key_len);
122
123	if (key_idx == 0) {
124		/*
125		 * In IBSS RSN, the pairwise key from the 4-way handshake
126		 * initiated by the peer with highest MAC address is used.
127		 */
128		if (os_memcmp(peer->ibss_rsn->wpa_s->own_addr, peer->addr,
129			      ETH_ALEN) > 0) {
130			wpa_printf(MSG_DEBUG, "SUPP: Do not use this PTK");
131			return 0;
132		}
133	}
134
135	if (is_broadcast_ether_addr(addr))
136		addr = peer->addr;
137	return wpa_drv_set_key(peer->ibss_rsn->wpa_s, alg, addr, key_idx,
138			       set_tx, seq, seq_len, key, key_len);
139}
140
141
142static void * supp_get_network_ctx(void *ctx)
143{
144	struct ibss_rsn_peer *peer = ctx;
145	return wpa_supplicant_get_ssid(peer->ibss_rsn->wpa_s);
146}
147
148
149static int supp_mlme_setprotection(void *ctx, const u8 *addr,
150				   int protection_type, int key_type)
151{
152	wpa_printf(MSG_DEBUG, "SUPP: %s(addr=" MACSTR " protection_type=%d "
153		   "key_type=%d)",
154		   __func__, MAC2STR(addr), protection_type, key_type);
155	return 0;
156}
157
158
159static void supp_cancel_auth_timeout(void *ctx)
160{
161	wpa_printf(MSG_DEBUG, "SUPP: %s", __func__);
162}
163
164
165static void supp_deauthenticate(void * ctx, int reason_code)
166{
167	wpa_printf(MSG_DEBUG, "SUPP: %s (TODO)", __func__);
168}
169
170
171int ibss_rsn_supp_init(struct ibss_rsn_peer *peer, const u8 *own_addr,
172		       const u8 *psk)
173{
174	struct wpa_sm_ctx *ctx = os_zalloc(sizeof(*ctx));
175	if (ctx == NULL)
176		return -1;
177
178	ctx->ctx = peer;
179	ctx->msg_ctx = peer->ibss_rsn->wpa_s;
180	ctx->set_state = supp_set_state;
181	ctx->get_state = supp_get_state;
182	ctx->ether_send = supp_ether_send;
183	ctx->get_beacon_ie = supp_get_beacon_ie;
184	ctx->alloc_eapol = supp_alloc_eapol;
185	ctx->set_key = supp_set_key;
186	ctx->get_network_ctx = supp_get_network_ctx;
187	ctx->mlme_setprotection = supp_mlme_setprotection;
188	ctx->cancel_auth_timeout = supp_cancel_auth_timeout;
189	ctx->deauthenticate = supp_deauthenticate;
190	peer->supp = wpa_sm_init(ctx);
191	if (peer->supp == NULL) {
192		wpa_printf(MSG_DEBUG, "SUPP: wpa_sm_init() failed");
193		return -1;
194	}
195
196	wpa_sm_set_own_addr(peer->supp, own_addr);
197	wpa_sm_set_param(peer->supp, WPA_PARAM_RSN_ENABLED, 1);
198	wpa_sm_set_param(peer->supp, WPA_PARAM_PROTO, WPA_PROTO_RSN);
199	wpa_sm_set_param(peer->supp, WPA_PARAM_PAIRWISE, WPA_CIPHER_CCMP);
200	wpa_sm_set_param(peer->supp, WPA_PARAM_GROUP, WPA_CIPHER_CCMP);
201	wpa_sm_set_param(peer->supp, WPA_PARAM_KEY_MGMT, WPA_KEY_MGMT_PSK);
202	wpa_sm_set_pmk(peer->supp, psk, PMK_LEN);
203
204	peer->supp_ie_len = sizeof(peer->supp_ie);
205	if (wpa_sm_set_assoc_wpa_ie_default(peer->supp, peer->supp_ie,
206					    &peer->supp_ie_len) < 0) {
207		wpa_printf(MSG_DEBUG, "SUPP: wpa_sm_set_assoc_wpa_ie_default()"
208			   " failed");
209		return -1;
210	}
211
212	wpa_sm_notify_assoc(peer->supp, peer->addr);
213
214	return 0;
215}
216
217
218static void auth_logger(void *ctx, const u8 *addr, logger_level level,
219			const char *txt)
220{
221	if (addr)
222		wpa_printf(MSG_DEBUG, "AUTH: " MACSTR " - %s",
223			   MAC2STR(addr), txt);
224	else
225		wpa_printf(MSG_DEBUG, "AUTH: %s", txt);
226}
227
228
229static const u8 * auth_get_psk(void *ctx, const u8 *addr, const u8 *prev_psk)
230{
231	struct ibss_rsn *ibss_rsn = ctx;
232	wpa_printf(MSG_DEBUG, "AUTH: %s (addr=" MACSTR " prev_psk=%p)",
233		   __func__, MAC2STR(addr), prev_psk);
234	if (prev_psk)
235		return NULL;
236	return ibss_rsn->psk;
237}
238
239
240static int auth_send_eapol(void *ctx, const u8 *addr, const u8 *data,
241			   size_t data_len, int encrypt)
242{
243	struct ibss_rsn *ibss_rsn = ctx;
244	struct wpa_supplicant *wpa_s = ibss_rsn->wpa_s;
245
246	wpa_printf(MSG_DEBUG, "AUTH: %s(addr=" MACSTR " data_len=%lu "
247		   "encrypt=%d)",
248		   __func__, MAC2STR(addr), (unsigned long) data_len, encrypt);
249
250	if (wpa_s->l2)
251		return l2_packet_send(wpa_s->l2, addr, ETH_P_EAPOL, data,
252				      data_len);
253
254	return wpa_drv_send_eapol(wpa_s, addr, ETH_P_EAPOL, data, data_len);
255}
256
257
258static int auth_set_key(void *ctx, int vlan_id, enum wpa_alg alg,
259			const u8 *addr, int idx, u8 *key, size_t key_len)
260{
261	struct ibss_rsn *ibss_rsn = ctx;
262	u8 seq[6];
263
264	os_memset(seq, 0, sizeof(seq));
265
266	if (addr) {
267		wpa_printf(MSG_DEBUG, "AUTH: %s(alg=%d addr=" MACSTR
268			   " key_idx=%d)",
269			   __func__, alg, MAC2STR(addr), idx);
270	} else {
271		wpa_printf(MSG_DEBUG, "AUTH: %s(alg=%d key_idx=%d)",
272			   __func__, alg, idx);
273	}
274	wpa_hexdump_key(MSG_DEBUG, "AUTH: set_key - key", key, key_len);
275
276	if (idx == 0) {
277		/*
278		 * In IBSS RSN, the pairwise key from the 4-way handshake
279		 * initiated by the peer with highest MAC address is used.
280		 */
281		if (addr == NULL ||
282		    os_memcmp(ibss_rsn->wpa_s->own_addr, addr, ETH_ALEN) < 0) {
283			wpa_printf(MSG_DEBUG, "AUTH: Do not use this PTK");
284			return 0;
285		}
286	}
287
288	return wpa_drv_set_key(ibss_rsn->wpa_s, alg, addr, idx,
289			       1, seq, 6, key, key_len);
290}
291
292
293static int auth_for_each_sta(void *ctx, int (*cb)(struct wpa_state_machine *sm,
294						  void *ctx),
295			     void *cb_ctx)
296{
297	struct ibss_rsn *ibss_rsn = ctx;
298	struct ibss_rsn_peer *peer;
299
300	wpa_printf(MSG_DEBUG, "AUTH: for_each_sta");
301
302	for (peer = ibss_rsn->peers; peer; peer = peer->next) {
303		if (peer->auth && cb(peer->auth, cb_ctx))
304			return 1;
305	}
306
307	return 0;
308}
309
310
311static int ibss_rsn_auth_init_group(struct ibss_rsn *ibss_rsn,
312				    const u8 *own_addr)
313{
314	struct wpa_auth_config conf;
315	struct wpa_auth_callbacks cb;
316
317	wpa_printf(MSG_DEBUG, "AUTH: Initializing group state machine");
318
319	os_memset(&conf, 0, sizeof(conf));
320	conf.wpa = 2;
321	conf.wpa_key_mgmt = WPA_KEY_MGMT_PSK;
322	conf.wpa_pairwise = WPA_CIPHER_CCMP;
323	conf.rsn_pairwise = WPA_CIPHER_CCMP;
324	conf.wpa_group = WPA_CIPHER_CCMP;
325	conf.eapol_version = 2;
326	conf.wpa_group_rekey = 600;
327
328	os_memset(&cb, 0, sizeof(cb));
329	cb.ctx = ibss_rsn;
330	cb.logger = auth_logger;
331	cb.send_eapol = auth_send_eapol;
332	cb.get_psk = auth_get_psk;
333	cb.set_key = auth_set_key;
334	cb.for_each_sta = auth_for_each_sta;
335
336	ibss_rsn->auth_group = wpa_init(own_addr, &conf, &cb);
337	if (ibss_rsn->auth_group == NULL) {
338		wpa_printf(MSG_DEBUG, "AUTH: wpa_init() failed");
339		return -1;
340	}
341
342	return 0;
343}
344
345
346static int ibss_rsn_auth_init(struct ibss_rsn *ibss_rsn,
347			      struct ibss_rsn_peer *peer)
348{
349	peer->auth = wpa_auth_sta_init(ibss_rsn->auth_group, peer->addr);
350	if (peer->auth == NULL) {
351		wpa_printf(MSG_DEBUG, "AUTH: wpa_auth_sta_init() failed");
352		return -1;
353	}
354
355	/* TODO: get peer RSN IE with Probe Request */
356	if (wpa_validate_wpa_ie(ibss_rsn->auth_group, peer->auth,
357				(u8 *) "\x30\x14\x01\x00"
358				"\x00\x0f\xac\x04"
359				"\x01\x00\x00\x0f\xac\x04"
360				"\x01\x00\x00\x0f\xac\x02"
361				"\x00\x00", 22, NULL, 0) !=
362	    WPA_IE_OK) {
363		wpa_printf(MSG_DEBUG, "AUTH: wpa_validate_wpa_ie() failed");
364		return -1;
365	}
366
367	if (wpa_auth_sm_event(peer->auth, WPA_ASSOC))
368		return -1;
369
370	if (wpa_auth_sta_associated(ibss_rsn->auth_group, peer->auth))
371		return -1;
372
373	return 0;
374}
375
376
377int ibss_rsn_start(struct ibss_rsn *ibss_rsn, const u8 *addr)
378{
379	struct ibss_rsn_peer *peer;
380
381	if (ibss_rsn == NULL)
382		return -1;
383
384	for (peer = ibss_rsn->peers; peer; peer = peer->next) {
385		if (os_memcmp(addr, peer->addr, ETH_ALEN) == 0) {
386			wpa_printf(MSG_DEBUG, "RSN: IBSS Authenticator and "
387				   "Supplicant for peer " MACSTR " already "
388				   "running", MAC2STR(addr));
389			return 0;
390		}
391	}
392
393	wpa_printf(MSG_DEBUG, "RSN: Starting IBSS Authenticator and "
394		   "Supplicant for peer " MACSTR, MAC2STR(addr));
395
396	peer = os_zalloc(sizeof(*peer));
397	if (peer == NULL)
398		return -1;
399
400	peer->ibss_rsn = ibss_rsn;
401	os_memcpy(peer->addr, addr, ETH_ALEN);
402
403	if (ibss_rsn_supp_init(peer, ibss_rsn->wpa_s->own_addr, ibss_rsn->psk)
404	    < 0) {
405		ibss_rsn_free(peer);
406		return -1;
407	}
408
409	if (ibss_rsn_auth_init(ibss_rsn, peer) < 0) {
410		ibss_rsn_free(peer);
411		return -1;
412	}
413
414	peer->next = ibss_rsn->peers;
415	ibss_rsn->peers = peer;
416
417	return 0;
418}
419
420
421void ibss_rsn_stop(struct ibss_rsn *ibss_rsn, const u8 *peermac)
422{
423	struct ibss_rsn_peer *peer, *prev;
424
425	if (ibss_rsn == NULL)
426		return;
427
428	if (peermac == NULL) {
429		/* remove all peers */
430		wpa_printf(MSG_DEBUG, "%s: Remove all peers", __func__);
431		peer = ibss_rsn->peers;
432		while (peer) {
433			prev = peer;
434			peer = peer->next;
435			ibss_rsn_free(prev);
436			ibss_rsn->peers = peer;
437		}
438	} else {
439		/* remove specific peer */
440		wpa_printf(MSG_DEBUG, "%s: Remove specific peer " MACSTR,
441			   __func__, MAC2STR(peermac));
442
443		for (prev = NULL, peer = ibss_rsn->peers; peer != NULL;
444		     prev = peer, peer = peer->next) {
445			if (os_memcmp(peermac, peer->addr, ETH_ALEN) == 0) {
446				if (prev == NULL)
447					ibss_rsn->peers = peer->next;
448				else
449					prev->next = peer->next;
450				ibss_rsn_free(peer);
451				wpa_printf(MSG_DEBUG, "%s: Successfully "
452					   "removed a specific peer",
453					   __func__);
454				break;
455			}
456		}
457	}
458}
459
460
461struct ibss_rsn * ibss_rsn_init(struct wpa_supplicant *wpa_s)
462{
463	struct ibss_rsn *ibss_rsn;
464
465	ibss_rsn = os_zalloc(sizeof(*ibss_rsn));
466	if (ibss_rsn == NULL)
467		return NULL;
468	ibss_rsn->wpa_s = wpa_s;
469
470	if (ibss_rsn_auth_init_group(ibss_rsn, wpa_s->own_addr) < 0) {
471		ibss_rsn_deinit(ibss_rsn);
472		return NULL;
473	}
474
475	return ibss_rsn;
476}
477
478
479void ibss_rsn_deinit(struct ibss_rsn *ibss_rsn)
480{
481	struct ibss_rsn_peer *peer, *prev;
482
483	if (ibss_rsn == NULL)
484		return;
485
486	peer = ibss_rsn->peers;
487	while (peer) {
488		prev = peer;
489		peer = peer->next;
490		ibss_rsn_free(prev);
491	}
492
493	wpa_deinit(ibss_rsn->auth_group);
494	os_free(ibss_rsn);
495
496}
497
498
499static int ibss_rsn_eapol_dst_supp(const u8 *buf, size_t len)
500{
501	const struct ieee802_1x_hdr *hdr;
502	const struct wpa_eapol_key *key;
503	u16 key_info;
504	size_t plen;
505
506	/* TODO: Support other EAPOL packets than just EAPOL-Key */
507
508	if (len < sizeof(*hdr) + sizeof(*key))
509		return -1;
510
511	hdr = (const struct ieee802_1x_hdr *) buf;
512	key = (const struct wpa_eapol_key *) (hdr + 1);
513	plen = be_to_host16(hdr->length);
514
515	if (hdr->version < EAPOL_VERSION) {
516		/* TODO: backwards compatibility */
517	}
518	if (hdr->type != IEEE802_1X_TYPE_EAPOL_KEY) {
519		wpa_printf(MSG_DEBUG, "RSN: EAPOL frame (type %u) discarded, "
520			"not a Key frame", hdr->type);
521		return -1;
522	}
523	if (plen > len - sizeof(*hdr) || plen < sizeof(*key)) {
524		wpa_printf(MSG_DEBUG, "RSN: EAPOL frame payload size %lu "
525			   "invalid (frame size %lu)",
526			   (unsigned long) plen, (unsigned long) len);
527		return -1;
528	}
529
530	if (key->type != EAPOL_KEY_TYPE_RSN) {
531		wpa_printf(MSG_DEBUG, "RSN: EAPOL-Key type (%d) unknown, "
532			   "discarded", key->type);
533		return -1;
534	}
535
536	key_info = WPA_GET_BE16(key->key_info);
537
538	return !!(key_info & WPA_KEY_INFO_ACK);
539}
540
541
542static int ibss_rsn_process_rx_eapol(struct ibss_rsn *ibss_rsn,
543				     struct ibss_rsn_peer *peer,
544				     const u8 *buf, size_t len)
545{
546	int supp;
547	u8 *tmp;
548
549	supp = ibss_rsn_eapol_dst_supp(buf, len);
550	if (supp < 0)
551		return -1;
552
553	tmp = os_malloc(len);
554	if (tmp == NULL)
555		return -1;
556	os_memcpy(tmp, buf, len);
557	if (supp) {
558		wpa_printf(MSG_DEBUG, "RSN: IBSS RX EAPOL for Supplicant");
559		wpa_sm_rx_eapol(peer->supp, peer->addr, tmp, len);
560	} else {
561		wpa_printf(MSG_DEBUG, "RSN: IBSS RX EAPOL for Authenticator");
562		wpa_receive(ibss_rsn->auth_group, peer->auth, tmp, len);
563	}
564	os_free(tmp);
565
566	return 1;
567}
568
569
570int ibss_rsn_rx_eapol(struct ibss_rsn *ibss_rsn, const u8 *src_addr,
571		      const u8 *buf, size_t len)
572{
573	struct ibss_rsn_peer *peer;
574
575	if (ibss_rsn == NULL)
576		return -1;
577
578	for (peer = ibss_rsn->peers; peer; peer = peer->next) {
579		if (os_memcmp(src_addr, peer->addr, ETH_ALEN) == 0)
580			return ibss_rsn_process_rx_eapol(ibss_rsn, peer,
581							 buf, len);
582	}
583
584	if (ibss_rsn_eapol_dst_supp(buf, len) > 0) {
585		/*
586		 * Create new IBSS peer based on an EAPOL message from the peer
587		 * Authenticator.
588		 */
589		if (ibss_rsn_start(ibss_rsn, src_addr) < 0)
590			return -1;
591		return ibss_rsn_process_rx_eapol(ibss_rsn, ibss_rsn->peers,
592						 buf, len);
593	}
594
595	return 0;
596}
597
598
599void ibss_rsn_set_psk(struct ibss_rsn *ibss_rsn, const u8 *psk)
600{
601	if (ibss_rsn == NULL)
602		return;
603	os_memcpy(ibss_rsn->psk, psk, PMK_LEN);
604}
605