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 
27 static 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 
35 static 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 
42 static int supp_ether_send(void *ctx, const u8 *dest, u16 proto, const u8 *buf,
43 			   size_t len)
44 {
45 	struct ibss_rsn_peer *peer = ctx;
46 	struct wpa_supplicant *wpa_s = peer->ibss_rsn->wpa_s;
47 
48 	wpa_printf(MSG_DEBUG, "SUPP: %s(dest=" MACSTR " proto=0x%04x "
49 		   "len=%lu)",
50 		   __func__, MAC2STR(dest), proto, (unsigned long) len);
51 
52 	if (wpa_s->l2)
53 		return l2_packet_send(wpa_s->l2, dest, proto, buf, len);
54 
55 	return wpa_drv_send_eapol(wpa_s, dest, proto, buf, len);
56 }
57 
58 
59 static u8 * supp_alloc_eapol(void *ctx, u8 type, const void *data,
60 			     u16 data_len, size_t *msg_len, void **data_pos)
61 {
62 	struct ieee802_1x_hdr *hdr;
63 
64 	wpa_printf(MSG_DEBUG, "SUPP: %s(type=%d data_len=%d)",
65 		   __func__, type, data_len);
66 
67 	*msg_len = sizeof(*hdr) + data_len;
68 	hdr = os_malloc(*msg_len);
69 	if (hdr == NULL)
70 		return NULL;
71 
72 	hdr->version = 2;
73 	hdr->type = type;
74 	hdr->length = host_to_be16(data_len);
75 
76 	if (data)
77 		os_memcpy(hdr + 1, data, data_len);
78 	else
79 		os_memset(hdr + 1, 0, data_len);
80 
81 	if (data_pos)
82 		*data_pos = hdr + 1;
83 
84 	return (u8 *) hdr;
85 }
86 
87 
88 static int supp_get_beacon_ie(void *ctx)
89 {
90 	struct ibss_rsn_peer *peer = ctx;
91 
92 	wpa_printf(MSG_DEBUG, "SUPP: %s", __func__);
93 	/* TODO: get correct RSN IE */
94 	return wpa_sm_set_ap_rsn_ie(peer->supp,
95 				    (u8 *) "\x30\x14\x01\x00"
96 				    "\x00\x0f\xac\x04"
97 				    "\x01\x00\x00\x0f\xac\x04"
98 				    "\x01\x00\x00\x0f\xac\x02"
99 				    "\x00\x00", 22);
100 }
101 
102 
103 static int supp_set_key(void *ctx, enum wpa_alg alg,
104 			const u8 *addr, int key_idx, int set_tx,
105 			const u8 *seq, size_t seq_len,
106 			const u8 *key, size_t key_len)
107 {
108 	struct ibss_rsn_peer *peer = ctx;
109 
110 	wpa_printf(MSG_DEBUG, "SUPP: %s(alg=%d addr=" MACSTR " key_idx=%d "
111 		   "set_tx=%d)",
112 		   __func__, alg, MAC2STR(addr), key_idx, set_tx);
113 	wpa_hexdump(MSG_DEBUG, "SUPP: set_key - seq", seq, seq_len);
114 	wpa_hexdump_key(MSG_DEBUG, "SUPP: set_key - key", key, key_len);
115 
116 	if (key_idx == 0) {
117 		/*
118 		 * In IBSS RSN, the pairwise key from the 4-way handshake
119 		 * initiated by the peer with highest MAC address is used.
120 		 */
121 		if (os_memcmp(peer->ibss_rsn->wpa_s->own_addr, peer->addr,
122 			      ETH_ALEN) > 0) {
123 			wpa_printf(MSG_DEBUG, "SUPP: Do not use this PTK");
124 			return 0;
125 		}
126 	}
127 
128 	return wpa_drv_set_key(peer->ibss_rsn->wpa_s, alg, addr, key_idx,
129 			       set_tx, seq, seq_len, key, key_len);
130 }
131 
132 
133 static void * supp_get_network_ctx(void *ctx)
134 {
135 	struct ibss_rsn_peer *peer = ctx;
136 	return wpa_supplicant_get_ssid(peer->ibss_rsn->wpa_s);
137 }
138 
139 
140 static int supp_mlme_setprotection(void *ctx, const u8 *addr,
141 				   int protection_type, int key_type)
142 {
143 	wpa_printf(MSG_DEBUG, "SUPP: %s(addr=" MACSTR " protection_type=%d "
144 		   "key_type=%d)",
145 		   __func__, MAC2STR(addr), protection_type, key_type);
146 	return 0;
147 }
148 
149 
150 static void supp_cancel_auth_timeout(void *ctx)
151 {
152 	wpa_printf(MSG_DEBUG, "SUPP: %s", __func__);
153 }
154 
155 
156 int ibss_rsn_supp_init(struct ibss_rsn_peer *peer, const u8 *own_addr,
157 		       const u8 *psk)
158 {
159 	struct wpa_sm_ctx *ctx = os_zalloc(sizeof(*ctx));
160 	if (ctx == NULL)
161 		return -1;
162 
163 	ctx->ctx = peer;
164 	ctx->msg_ctx = peer->ibss_rsn->wpa_s;
165 	ctx->set_state = supp_set_state;
166 	ctx->ether_send = supp_ether_send;
167 	ctx->get_beacon_ie = supp_get_beacon_ie;
168 	ctx->alloc_eapol = supp_alloc_eapol;
169 	ctx->set_key = supp_set_key;
170 	ctx->get_network_ctx = supp_get_network_ctx;
171 	ctx->mlme_setprotection = supp_mlme_setprotection;
172 	ctx->cancel_auth_timeout = supp_cancel_auth_timeout;
173 	peer->supp = wpa_sm_init(ctx);
174 	if (peer->supp == NULL) {
175 		wpa_printf(MSG_DEBUG, "SUPP: wpa_sm_init() failed");
176 		return -1;
177 	}
178 
179 	wpa_sm_set_own_addr(peer->supp, own_addr);
180 	wpa_sm_set_param(peer->supp, WPA_PARAM_RSN_ENABLED, 1);
181 	wpa_sm_set_param(peer->supp, WPA_PARAM_PROTO, WPA_PROTO_RSN);
182 	wpa_sm_set_param(peer->supp, WPA_PARAM_PAIRWISE, WPA_CIPHER_CCMP);
183 	wpa_sm_set_param(peer->supp, WPA_PARAM_GROUP, WPA_CIPHER_CCMP);
184 	wpa_sm_set_param(peer->supp, WPA_PARAM_KEY_MGMT, WPA_KEY_MGMT_PSK);
185 	wpa_sm_set_pmk(peer->supp, psk, PMK_LEN);
186 
187 	peer->supp_ie_len = sizeof(peer->supp_ie);
188 	if (wpa_sm_set_assoc_wpa_ie_default(peer->supp, peer->supp_ie,
189 					    &peer->supp_ie_len) < 0) {
190 		wpa_printf(MSG_DEBUG, "SUPP: wpa_sm_set_assoc_wpa_ie_default()"
191 			   " failed");
192 		return -1;
193 	}
194 
195 	wpa_sm_notify_assoc(peer->supp, peer->addr);
196 
197 	return 0;
198 }
199 
200 
201 static void auth_logger(void *ctx, const u8 *addr, logger_level level,
202 			const char *txt)
203 {
204 	if (addr)
205 		wpa_printf(MSG_DEBUG, "AUTH: " MACSTR " - %s",
206 			   MAC2STR(addr), txt);
207 	else
208 		wpa_printf(MSG_DEBUG, "AUTH: %s", txt);
209 }
210 
211 
212 static const u8 * auth_get_psk(void *ctx, const u8 *addr, const u8 *prev_psk)
213 {
214 	struct ibss_rsn *ibss_rsn = ctx;
215 	wpa_printf(MSG_DEBUG, "AUTH: %s (addr=" MACSTR " prev_psk=%p)",
216 		   __func__, MAC2STR(addr), prev_psk);
217 	if (prev_psk)
218 		return NULL;
219 	return ibss_rsn->psk;
220 }
221 
222 
223 static int auth_send_eapol(void *ctx, const u8 *addr, const u8 *data,
224 			   size_t data_len, int encrypt)
225 {
226 	struct ibss_rsn *ibss_rsn = ctx;
227 	struct wpa_supplicant *wpa_s = ibss_rsn->wpa_s;
228 
229 	wpa_printf(MSG_DEBUG, "AUTH: %s(addr=" MACSTR " data_len=%lu "
230 		   "encrypt=%d)",
231 		   __func__, MAC2STR(addr), (unsigned long) data_len, encrypt);
232 
233 	if (wpa_s->l2)
234 		return l2_packet_send(wpa_s->l2, addr, ETH_P_EAPOL, data,
235 				      data_len);
236 
237 	return wpa_drv_send_eapol(wpa_s, addr, ETH_P_EAPOL, data, data_len);
238 }
239 
240 
241 static int auth_set_key(void *ctx, int vlan_id, enum wpa_alg alg,
242 			const u8 *addr, int idx, u8 *key, size_t key_len)
243 {
244 	struct ibss_rsn *ibss_rsn = ctx;
245 	u8 seq[6];
246 
247 	os_memset(seq, 0, sizeof(seq));
248 
249 	if (addr) {
250 		wpa_printf(MSG_DEBUG, "AUTH: %s(alg=%d addr=" MACSTR
251 			   " key_idx=%d)",
252 			   __func__, alg, MAC2STR(addr), idx);
253 	} else {
254 		wpa_printf(MSG_DEBUG, "AUTH: %s(alg=%d key_idx=%d)",
255 			   __func__, alg, idx);
256 	}
257 	wpa_hexdump_key(MSG_DEBUG, "AUTH: set_key - key", key, key_len);
258 
259 	if (idx == 0) {
260 		/*
261 		 * In IBSS RSN, the pairwise key from the 4-way handshake
262 		 * initiated by the peer with highest MAC address is used.
263 		 */
264 		if (addr == NULL ||
265 		    os_memcmp(ibss_rsn->wpa_s->own_addr, addr, ETH_ALEN) < 0) {
266 			wpa_printf(MSG_DEBUG, "AUTH: Do not use this PTK");
267 			return 0;
268 		}
269 	}
270 
271 	return wpa_drv_set_key(ibss_rsn->wpa_s, alg, addr, idx,
272 			       1, seq, 6, key, key_len);
273 }
274 
275 
276 static int ibss_rsn_auth_init_group(struct ibss_rsn *ibss_rsn,
277 				    const u8 *own_addr)
278 {
279 	struct wpa_auth_config conf;
280 	struct wpa_auth_callbacks cb;
281 
282 	wpa_printf(MSG_DEBUG, "AUTH: Initializing group state machine");
283 
284 	os_memset(&conf, 0, sizeof(conf));
285 	conf.wpa = 2;
286 	conf.wpa_key_mgmt = WPA_KEY_MGMT_PSK;
287 	conf.wpa_pairwise = WPA_CIPHER_CCMP;
288 	conf.rsn_pairwise = WPA_CIPHER_CCMP;
289 	conf.wpa_group = WPA_CIPHER_CCMP;
290 	conf.eapol_version = 2;
291 
292 	os_memset(&cb, 0, sizeof(cb));
293 	cb.ctx = ibss_rsn;
294 	cb.logger = auth_logger;
295 	cb.send_eapol = auth_send_eapol;
296 	cb.get_psk = auth_get_psk;
297 	cb.set_key = auth_set_key;
298 
299 	ibss_rsn->auth_group = wpa_init(own_addr, &conf, &cb);
300 	if (ibss_rsn->auth_group == NULL) {
301 		wpa_printf(MSG_DEBUG, "AUTH: wpa_init() failed");
302 		return -1;
303 	}
304 
305 	return 0;
306 }
307 
308 
309 static int ibss_rsn_auth_init(struct ibss_rsn *ibss_rsn,
310 			      struct ibss_rsn_peer *peer)
311 {
312 	peer->auth = wpa_auth_sta_init(ibss_rsn->auth_group, peer->addr);
313 	if (peer->auth == NULL) {
314 		wpa_printf(MSG_DEBUG, "AUTH: wpa_auth_sta_init() failed");
315 		return -1;
316 	}
317 
318 	/* TODO: get peer RSN IE with Probe Request */
319 	if (wpa_validate_wpa_ie(ibss_rsn->auth_group, peer->auth,
320 				(u8 *) "\x30\x14\x01\x00"
321 				"\x00\x0f\xac\x04"
322 				"\x01\x00\x00\x0f\xac\x04"
323 				"\x01\x00\x00\x0f\xac\x02"
324 				"\x00\x00", 22, NULL, 0) !=
325 	    WPA_IE_OK) {
326 		wpa_printf(MSG_DEBUG, "AUTH: wpa_validate_wpa_ie() failed");
327 		return -1;
328 	}
329 
330 	if (wpa_auth_sm_event(peer->auth, WPA_ASSOC))
331 		return -1;
332 
333 	if (wpa_auth_sta_associated(ibss_rsn->auth_group, peer->auth))
334 		return -1;
335 
336 	return 0;
337 }
338 
339 
340 int ibss_rsn_start(struct ibss_rsn *ibss_rsn, const u8 *addr)
341 {
342 	struct ibss_rsn_peer *peer;
343 
344 	wpa_printf(MSG_DEBUG, "RSN: Starting IBSS Authenticator and "
345 		   "Supplicant for peer " MACSTR, MAC2STR(addr));
346 
347 	peer = os_zalloc(sizeof(*peer));
348 	if (peer == NULL)
349 		return -1;
350 
351 	peer->ibss_rsn = ibss_rsn;
352 	os_memcpy(peer->addr, addr, ETH_ALEN);
353 
354 	if (ibss_rsn_supp_init(peer, ibss_rsn->wpa_s->own_addr, ibss_rsn->psk)
355 	    < 0) {
356 		ibss_rsn_free(peer);
357 		return -1;
358 	}
359 
360 	if (ibss_rsn_auth_init(ibss_rsn, peer) < 0) {
361 		ibss_rsn_free(peer);
362 		return -1;
363 	}
364 
365 	peer->next = ibss_rsn->peers;
366 	ibss_rsn->peers = peer;
367 
368 	return 0;
369 }
370 
371 
372 struct ibss_rsn * ibss_rsn_init(struct wpa_supplicant *wpa_s)
373 {
374 	struct ibss_rsn *ibss_rsn;
375 
376 	ibss_rsn = os_zalloc(sizeof(*ibss_rsn));
377 	if (ibss_rsn == NULL)
378 		return NULL;
379 	ibss_rsn->wpa_s = wpa_s;
380 
381 	if (ibss_rsn_auth_init_group(ibss_rsn, wpa_s->own_addr) < 0) {
382 		ibss_rsn_deinit(ibss_rsn);
383 		return NULL;
384 	}
385 
386 	return ibss_rsn;
387 }
388 
389 
390 void ibss_rsn_deinit(struct ibss_rsn *ibss_rsn)
391 {
392 	struct ibss_rsn_peer *peer, *prev;
393 
394 	if (ibss_rsn == NULL)
395 		return;
396 
397 	peer = ibss_rsn->peers;
398 	while (peer) {
399 		prev = peer;
400 		peer = peer->next;
401 		ibss_rsn_free(prev);
402 	}
403 
404 	wpa_deinit(ibss_rsn->auth_group);
405 	os_free(ibss_rsn);
406 
407 }
408 
409 
410 static int ibss_rsn_eapol_dst_supp(const u8 *buf, size_t len)
411 {
412 	const struct ieee802_1x_hdr *hdr;
413 	const struct wpa_eapol_key *key;
414 	u16 key_info;
415 	size_t plen;
416 
417 	/* TODO: Support other EAPOL packets than just EAPOL-Key */
418 
419 	if (len < sizeof(*hdr) + sizeof(*key))
420 		return -1;
421 
422 	hdr = (const struct ieee802_1x_hdr *) buf;
423 	key = (const struct wpa_eapol_key *) (hdr + 1);
424 	plen = be_to_host16(hdr->length);
425 
426 	if (hdr->version < EAPOL_VERSION) {
427 		/* TODO: backwards compatibility */
428 	}
429 	if (hdr->type != IEEE802_1X_TYPE_EAPOL_KEY) {
430 		wpa_printf(MSG_DEBUG, "RSN: EAPOL frame (type %u) discarded, "
431 			"not a Key frame", hdr->type);
432 		return -1;
433 	}
434 	if (plen > len - sizeof(*hdr) || plen < sizeof(*key)) {
435 		wpa_printf(MSG_DEBUG, "RSN: EAPOL frame payload size %lu "
436 			   "invalid (frame size %lu)",
437 			   (unsigned long) plen, (unsigned long) len);
438 		return -1;
439 	}
440 
441 	if (key->type != EAPOL_KEY_TYPE_RSN) {
442 		wpa_printf(MSG_DEBUG, "RSN: EAPOL-Key type (%d) unknown, "
443 			   "discarded", key->type);
444 		return -1;
445 	}
446 
447 	key_info = WPA_GET_BE16(key->key_info);
448 
449 	return !!(key_info & WPA_KEY_INFO_ACK);
450 }
451 
452 
453 static int ibss_rsn_process_rx_eapol(struct ibss_rsn *ibss_rsn,
454 				     struct ibss_rsn_peer *peer,
455 				     const u8 *buf, size_t len)
456 {
457 	int supp;
458 	u8 *tmp;
459 
460 	supp = ibss_rsn_eapol_dst_supp(buf, len);
461 	if (supp < 0)
462 		return -1;
463 
464 	tmp = os_malloc(len);
465 	if (tmp == NULL)
466 		return -1;
467 	os_memcpy(tmp, buf, len);
468 	if (supp) {
469 		wpa_printf(MSG_DEBUG, "RSN: IBSS RX EAPOL for Supplicant");
470 		wpa_sm_rx_eapol(peer->supp, peer->addr, tmp, len);
471 	} else {
472 		wpa_printf(MSG_DEBUG, "RSN: IBSS RX EAPOL for Authenticator");
473 		wpa_receive(ibss_rsn->auth_group, peer->auth, tmp, len);
474 	}
475 	os_free(tmp);
476 
477 	return 1;
478 }
479 
480 
481 int ibss_rsn_rx_eapol(struct ibss_rsn *ibss_rsn, const u8 *src_addr,
482 		      const u8 *buf, size_t len)
483 {
484 	struct ibss_rsn_peer *peer;
485 
486 	for (peer = ibss_rsn->peers; peer; peer = peer->next) {
487 		if (os_memcmp(src_addr, peer->addr, ETH_ALEN) == 0)
488 			return ibss_rsn_process_rx_eapol(ibss_rsn, peer,
489 							 buf, len);
490 	}
491 
492 	if (ibss_rsn_eapol_dst_supp(buf, len) > 0) {
493 		/*
494 		 * Create new IBSS peer based on an EAPOL message from the peer
495 		 * Authenticator.
496 		 */
497 		if (ibss_rsn_start(ibss_rsn, src_addr) < 0)
498 			return -1;
499 		return ibss_rsn_process_rx_eapol(ibss_rsn, ibss_rsn->peers,
500 						 buf, len);
501 	}
502 
503 	return 0;
504 }
505 
506 
507 void ibss_rsn_set_psk(struct ibss_rsn *ibss_rsn, const u8 *psk)
508 {
509 	os_memcpy(ibss_rsn->psk, psk, PMK_LEN);
510 }
511