1/*
2 * WPA Supplicant - IEEE 802.11r - Fast BSS Transition
3 * Copyright (c) 2006-2007, 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 "includes.h"
10
11#include "common.h"
12#include "crypto/aes_wrap.h"
13#include "crypto/random.h"
14#include "common/ieee802_11_defs.h"
15#include "common/ieee802_11_common.h"
16#include "wpa.h"
17#include "wpa_i.h"
18
19#ifdef CONFIG_IEEE80211R
20
21int wpa_derive_ptk_ft(struct wpa_sm *sm, const unsigned char *src_addr,
22		      const struct wpa_eapol_key *key,
23		      struct wpa_ptk *ptk, size_t ptk_len)
24{
25	u8 ptk_name[WPA_PMK_NAME_LEN];
26	const u8 *anonce = key->key_nonce;
27
28	if (sm->xxkey_len == 0) {
29		wpa_printf(MSG_DEBUG, "FT: XXKey not available for key "
30			   "derivation");
31		return -1;
32	}
33
34	wpa_derive_pmk_r0(sm->xxkey, sm->xxkey_len, sm->ssid,
35			  sm->ssid_len, sm->mobility_domain,
36			  sm->r0kh_id, sm->r0kh_id_len, sm->own_addr,
37			  sm->pmk_r0, sm->pmk_r0_name);
38	wpa_hexdump_key(MSG_DEBUG, "FT: PMK-R0", sm->pmk_r0, PMK_LEN);
39	wpa_hexdump(MSG_DEBUG, "FT: PMKR0Name",
40		    sm->pmk_r0_name, WPA_PMK_NAME_LEN);
41	wpa_derive_pmk_r1(sm->pmk_r0, sm->pmk_r0_name, sm->r1kh_id,
42			  sm->own_addr, sm->pmk_r1, sm->pmk_r1_name);
43	wpa_hexdump_key(MSG_DEBUG, "FT: PMK-R1", sm->pmk_r1, PMK_LEN);
44	wpa_hexdump(MSG_DEBUG, "FT: PMKR1Name", sm->pmk_r1_name,
45		    WPA_PMK_NAME_LEN);
46	wpa_pmk_r1_to_ptk(sm->pmk_r1, sm->snonce, anonce, sm->own_addr,
47			  sm->bssid, sm->pmk_r1_name,
48			  (u8 *) ptk, ptk_len, ptk_name);
49	wpa_hexdump_key(MSG_DEBUG, "FT: PTK", (u8 *) ptk, ptk_len);
50	wpa_hexdump(MSG_DEBUG, "FT: PTKName", ptk_name, WPA_PMK_NAME_LEN);
51
52	return 0;
53}
54
55
56/**
57 * wpa_sm_set_ft_params - Set FT (IEEE 802.11r) parameters
58 * @sm: Pointer to WPA state machine data from wpa_sm_init()
59 * @ies: Association Response IEs or %NULL to clear FT parameters
60 * @ies_len: Length of ies buffer in octets
61 * Returns: 0 on success, -1 on failure
62 */
63int wpa_sm_set_ft_params(struct wpa_sm *sm, const u8 *ies, size_t ies_len)
64{
65	struct wpa_ft_ies ft;
66
67	if (sm == NULL)
68		return 0;
69
70	if (wpa_ft_parse_ies(ies, ies_len, &ft) < 0)
71		return -1;
72
73	if (ft.mdie && ft.mdie_len < MOBILITY_DOMAIN_ID_LEN + 1)
74		return -1;
75
76	if (ft.mdie) {
77		wpa_hexdump(MSG_DEBUG, "FT: Mobility domain",
78			    ft.mdie, MOBILITY_DOMAIN_ID_LEN);
79		os_memcpy(sm->mobility_domain, ft.mdie,
80			  MOBILITY_DOMAIN_ID_LEN);
81		sm->mdie_ft_capab = ft.mdie[MOBILITY_DOMAIN_ID_LEN];
82		wpa_printf(MSG_DEBUG, "FT: Capability and Policy: 0x%02x",
83			   sm->mdie_ft_capab);
84	} else
85		os_memset(sm->mobility_domain, 0, MOBILITY_DOMAIN_ID_LEN);
86
87	if (ft.r0kh_id) {
88		wpa_hexdump(MSG_DEBUG, "FT: R0KH-ID",
89			    ft.r0kh_id, ft.r0kh_id_len);
90		os_memcpy(sm->r0kh_id, ft.r0kh_id, ft.r0kh_id_len);
91		sm->r0kh_id_len = ft.r0kh_id_len;
92	} else {
93		/* FIX: When should R0KH-ID be cleared? We need to keep the
94		 * old R0KH-ID in order to be able to use this during FT. */
95		/*
96		 * os_memset(sm->r0kh_id, 0, FT_R0KH_ID_LEN);
97		 * sm->r0kh_id_len = 0;
98		 */
99	}
100
101	if (ft.r1kh_id) {
102		wpa_hexdump(MSG_DEBUG, "FT: R1KH-ID",
103			    ft.r1kh_id, FT_R1KH_ID_LEN);
104		os_memcpy(sm->r1kh_id, ft.r1kh_id, FT_R1KH_ID_LEN);
105	} else
106		os_memset(sm->r1kh_id, 0, FT_R1KH_ID_LEN);
107
108	os_free(sm->assoc_resp_ies);
109	sm->assoc_resp_ies = os_malloc(ft.mdie_len + 2 + ft.ftie_len + 2);
110	if (sm->assoc_resp_ies) {
111		u8 *pos = sm->assoc_resp_ies;
112		if (ft.mdie) {
113			os_memcpy(pos, ft.mdie - 2, ft.mdie_len + 2);
114			pos += ft.mdie_len + 2;
115		}
116		if (ft.ftie) {
117			os_memcpy(pos, ft.ftie - 2, ft.ftie_len + 2);
118			pos += ft.ftie_len + 2;
119		}
120		sm->assoc_resp_ies_len = pos - sm->assoc_resp_ies;
121		wpa_hexdump(MSG_DEBUG, "FT: Stored MDIE and FTIE from "
122			    "(Re)Association Response",
123			    sm->assoc_resp_ies, sm->assoc_resp_ies_len);
124	}
125
126	return 0;
127}
128
129
130/**
131 * wpa_ft_gen_req_ies - Generate FT (IEEE 802.11r) IEs for Auth/ReAssoc Request
132 * @sm: Pointer to WPA state machine data from wpa_sm_init()
133 * @len: Buffer for returning the length of the IEs
134 * @anonce: ANonce or %NULL if not yet available
135 * @pmk_name: PMKR0Name or PMKR1Name to be added into the RSN IE PMKID List
136 * @kck: 128-bit KCK for MIC or %NULL if no MIC is used
137 * @target_ap: Target AP address
138 * @ric_ies: Optional IE(s), e.g., WMM TSPEC(s), for RIC-Request or %NULL
139 * @ric_ies_len: Length of ric_ies buffer in octets
140 * @ap_mdie: Mobility Domain IE from the target AP
141 * Returns: Pointer to buffer with IEs or %NULL on failure
142 *
143 * Caller is responsible for freeing the returned buffer with os_free();
144 */
145static u8 * wpa_ft_gen_req_ies(struct wpa_sm *sm, size_t *len,
146			       const u8 *anonce, const u8 *pmk_name,
147			       const u8 *kck, const u8 *target_ap,
148			       const u8 *ric_ies, size_t ric_ies_len,
149			       const u8 *ap_mdie)
150{
151	size_t buf_len;
152	u8 *buf, *pos, *ftie_len, *ftie_pos;
153	struct rsn_mdie *mdie;
154	struct rsn_ftie *ftie;
155	struct rsn_ie_hdr *rsnie;
156	u16 capab;
157
158	sm->ft_completed = 0;
159
160	buf_len = 2 + sizeof(struct rsn_mdie) + 2 + sizeof(struct rsn_ftie) +
161		2 + sm->r0kh_id_len + ric_ies_len + 100;
162	buf = os_zalloc(buf_len);
163	if (buf == NULL)
164		return NULL;
165	pos = buf;
166
167	/* RSNIE[PMKR0Name/PMKR1Name] */
168	rsnie = (struct rsn_ie_hdr *) pos;
169	rsnie->elem_id = WLAN_EID_RSN;
170	WPA_PUT_LE16(rsnie->version, RSN_VERSION);
171	pos = (u8 *) (rsnie + 1);
172
173	/* Group Suite Selector */
174	if (sm->group_cipher != WPA_CIPHER_CCMP &&
175	    sm->group_cipher != WPA_CIPHER_GCMP &&
176	    sm->group_cipher != WPA_CIPHER_TKIP) {
177		wpa_printf(MSG_WARNING, "FT: Invalid group cipher (%d)",
178			   sm->group_cipher);
179		os_free(buf);
180		return NULL;
181	}
182	RSN_SELECTOR_PUT(pos, wpa_cipher_to_suite(WPA_PROTO_RSN,
183						  sm->group_cipher));
184	pos += RSN_SELECTOR_LEN;
185
186	/* Pairwise Suite Count */
187	WPA_PUT_LE16(pos, 1);
188	pos += 2;
189
190	/* Pairwise Suite List */
191	if (!wpa_cipher_valid_pairwise(sm->pairwise_cipher)) {
192		wpa_printf(MSG_WARNING, "FT: Invalid pairwise cipher (%d)",
193			   sm->pairwise_cipher);
194		os_free(buf);
195		return NULL;
196	}
197	RSN_SELECTOR_PUT(pos, wpa_cipher_to_suite(WPA_PROTO_RSN,
198						  sm->pairwise_cipher));
199	pos += RSN_SELECTOR_LEN;
200
201	/* Authenticated Key Management Suite Count */
202	WPA_PUT_LE16(pos, 1);
203	pos += 2;
204
205	/* Authenticated Key Management Suite List */
206	if (sm->key_mgmt == WPA_KEY_MGMT_FT_IEEE8021X)
207		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_FT_802_1X);
208	else if (sm->key_mgmt == WPA_KEY_MGMT_FT_PSK)
209		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_FT_PSK);
210	else {
211		wpa_printf(MSG_WARNING, "FT: Invalid key management type (%d)",
212			   sm->key_mgmt);
213		os_free(buf);
214		return NULL;
215	}
216	pos += RSN_SELECTOR_LEN;
217
218	/* RSN Capabilities */
219	capab = 0;
220#ifdef CONFIG_IEEE80211W
221	if (sm->mgmt_group_cipher == WPA_CIPHER_AES_128_CMAC)
222		capab |= WPA_CAPABILITY_MFPC;
223#endif /* CONFIG_IEEE80211W */
224	WPA_PUT_LE16(pos, capab);
225	pos += 2;
226
227	/* PMKID Count */
228	WPA_PUT_LE16(pos, 1);
229	pos += 2;
230
231	/* PMKID List [PMKR0Name/PMKR1Name] */
232	os_memcpy(pos, pmk_name, WPA_PMK_NAME_LEN);
233	pos += WPA_PMK_NAME_LEN;
234
235#ifdef CONFIG_IEEE80211W
236	if (sm->mgmt_group_cipher == WPA_CIPHER_AES_128_CMAC) {
237		/* Management Group Cipher Suite */
238		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_AES_128_CMAC);
239		pos += RSN_SELECTOR_LEN;
240	}
241#endif /* CONFIG_IEEE80211W */
242
243	rsnie->len = (pos - (u8 *) rsnie) - 2;
244
245	/* MDIE */
246	*pos++ = WLAN_EID_MOBILITY_DOMAIN;
247	*pos++ = sizeof(*mdie);
248	mdie = (struct rsn_mdie *) pos;
249	pos += sizeof(*mdie);
250	os_memcpy(mdie->mobility_domain, sm->mobility_domain,
251		  MOBILITY_DOMAIN_ID_LEN);
252	mdie->ft_capab = ap_mdie && ap_mdie[1] >= 3 ? ap_mdie[4] :
253		sm->mdie_ft_capab;
254
255	/* FTIE[SNonce, [R1KH-ID,] R0KH-ID ] */
256	ftie_pos = pos;
257	*pos++ = WLAN_EID_FAST_BSS_TRANSITION;
258	ftie_len = pos++;
259	ftie = (struct rsn_ftie *) pos;
260	pos += sizeof(*ftie);
261	os_memcpy(ftie->snonce, sm->snonce, WPA_NONCE_LEN);
262	if (anonce)
263		os_memcpy(ftie->anonce, anonce, WPA_NONCE_LEN);
264	if (kck) {
265		/* R1KH-ID sub-element in third FT message */
266		*pos++ = FTIE_SUBELEM_R1KH_ID;
267		*pos++ = FT_R1KH_ID_LEN;
268		os_memcpy(pos, sm->r1kh_id, FT_R1KH_ID_LEN);
269		pos += FT_R1KH_ID_LEN;
270	}
271	/* R0KH-ID sub-element */
272	*pos++ = FTIE_SUBELEM_R0KH_ID;
273	*pos++ = sm->r0kh_id_len;
274	os_memcpy(pos, sm->r0kh_id, sm->r0kh_id_len);
275	pos += sm->r0kh_id_len;
276	*ftie_len = pos - ftie_len - 1;
277
278	if (ric_ies) {
279		/* RIC Request */
280		os_memcpy(pos, ric_ies, ric_ies_len);
281		pos += ric_ies_len;
282	}
283
284	if (kck) {
285		/*
286		 * IEEE Std 802.11r-2008, 11A.8.4
287		 * MIC shall be calculated over:
288		 * non-AP STA MAC address
289		 * Target AP MAC address
290		 * Transaction seq number (5 for ReassocReq, 3 otherwise)
291		 * RSN IE
292		 * MDIE
293		 * FTIE (with MIC field set to 0)
294		 * RIC-Request (if present)
295		 */
296		/* Information element count */
297		ftie->mic_control[1] = 3 + ieee802_11_ie_count(ric_ies,
298							       ric_ies_len);
299		if (wpa_ft_mic(kck, sm->own_addr, target_ap, 5,
300			       ((u8 *) mdie) - 2, 2 + sizeof(*mdie),
301			       ftie_pos, 2 + *ftie_len,
302			       (u8 *) rsnie, 2 + rsnie->len, ric_ies,
303			       ric_ies_len, ftie->mic) < 0) {
304			wpa_printf(MSG_INFO, "FT: Failed to calculate MIC");
305			os_free(buf);
306			return NULL;
307		}
308	}
309
310	*len = pos - buf;
311
312	return buf;
313}
314
315
316static int wpa_ft_install_ptk(struct wpa_sm *sm, const u8 *bssid)
317{
318	int keylen;
319	enum wpa_alg alg;
320	u8 null_rsc[6] = { 0, 0, 0, 0, 0, 0 };
321
322	wpa_printf(MSG_DEBUG, "FT: Installing PTK to the driver.");
323
324	if (!wpa_cipher_valid_pairwise(sm->pairwise_cipher)) {
325		wpa_printf(MSG_WARNING, "FT: Unsupported pairwise cipher %d",
326			   sm->pairwise_cipher);
327		return -1;
328	}
329
330	alg = wpa_cipher_to_alg(sm->pairwise_cipher);
331	keylen = wpa_cipher_key_len(sm->pairwise_cipher);
332
333	if (wpa_sm_set_key(sm, alg, bssid, 0, 1, null_rsc,
334			   sizeof(null_rsc), (u8 *) sm->ptk.tk1, keylen) < 0) {
335		wpa_printf(MSG_WARNING, "FT: Failed to set PTK to the driver");
336		return -1;
337	}
338
339	return 0;
340}
341
342
343/**
344 * wpa_ft_prepare_auth_request - Generate over-the-air auth request
345 * @sm: Pointer to WPA state machine data from wpa_sm_init()
346 * @mdie: Target AP MDIE
347 * Returns: 0 on success, -1 on failure
348 */
349int wpa_ft_prepare_auth_request(struct wpa_sm *sm, const u8 *mdie)
350{
351	u8 *ft_ies;
352	size_t ft_ies_len;
353
354	/* Generate a new SNonce */
355	if (random_get_bytes(sm->snonce, WPA_NONCE_LEN)) {
356		wpa_printf(MSG_INFO, "FT: Failed to generate a new SNonce");
357		return -1;
358	}
359
360	ft_ies = wpa_ft_gen_req_ies(sm, &ft_ies_len, NULL, sm->pmk_r0_name,
361				    NULL, sm->bssid, NULL, 0, mdie);
362	if (ft_ies) {
363		wpa_sm_update_ft_ies(sm, sm->mobility_domain,
364				     ft_ies, ft_ies_len);
365		os_free(ft_ies);
366	}
367
368	return 0;
369}
370
371
372int wpa_ft_process_response(struct wpa_sm *sm, const u8 *ies, size_t ies_len,
373			    int ft_action, const u8 *target_ap,
374			    const u8 *ric_ies, size_t ric_ies_len)
375{
376	u8 *ft_ies;
377	size_t ft_ies_len, ptk_len;
378	struct wpa_ft_ies parse;
379	struct rsn_mdie *mdie;
380	struct rsn_ftie *ftie;
381	u8 ptk_name[WPA_PMK_NAME_LEN];
382	int ret;
383	const u8 *bssid;
384
385	wpa_hexdump(MSG_DEBUG, "FT: Response IEs", ies, ies_len);
386	wpa_hexdump(MSG_DEBUG, "FT: RIC IEs", ric_ies, ric_ies_len);
387
388	if (ft_action) {
389		if (!sm->over_the_ds_in_progress) {
390			wpa_printf(MSG_DEBUG, "FT: No over-the-DS in progress "
391				   "- drop FT Action Response");
392			return -1;
393		}
394
395		if (os_memcmp(target_ap, sm->target_ap, ETH_ALEN) != 0) {
396			wpa_printf(MSG_DEBUG, "FT: No over-the-DS in progress "
397				   "with this Target AP - drop FT Action "
398				   "Response");
399			return -1;
400		}
401	}
402
403	if (sm->key_mgmt != WPA_KEY_MGMT_FT_IEEE8021X &&
404	    sm->key_mgmt != WPA_KEY_MGMT_FT_PSK) {
405		wpa_printf(MSG_DEBUG, "FT: Reject FT IEs since FT is not "
406			   "enabled for this connection");
407		return -1;
408	}
409
410	if (wpa_ft_parse_ies(ies, ies_len, &parse) < 0) {
411		wpa_printf(MSG_DEBUG, "FT: Failed to parse IEs");
412		return -1;
413	}
414
415	mdie = (struct rsn_mdie *) parse.mdie;
416	if (mdie == NULL || parse.mdie_len < sizeof(*mdie) ||
417	    os_memcmp(mdie->mobility_domain, sm->mobility_domain,
418		      MOBILITY_DOMAIN_ID_LEN) != 0) {
419		wpa_printf(MSG_DEBUG, "FT: Invalid MDIE");
420		return -1;
421	}
422
423	ftie = (struct rsn_ftie *) parse.ftie;
424	if (ftie == NULL || parse.ftie_len < sizeof(*ftie)) {
425		wpa_printf(MSG_DEBUG, "FT: Invalid FTIE");
426		return -1;
427	}
428
429	if (os_memcmp(ftie->snonce, sm->snonce, WPA_NONCE_LEN) != 0) {
430		wpa_printf(MSG_DEBUG, "FT: SNonce mismatch in FTIE");
431		wpa_hexdump(MSG_DEBUG, "FT: Received SNonce",
432			    ftie->snonce, WPA_NONCE_LEN);
433		wpa_hexdump(MSG_DEBUG, "FT: Expected SNonce",
434			    sm->snonce, WPA_NONCE_LEN);
435		return -1;
436	}
437
438	if (parse.r0kh_id == NULL) {
439		wpa_printf(MSG_DEBUG, "FT: No R0KH-ID subelem in FTIE");
440		return -1;
441	}
442
443	if (parse.r0kh_id_len != sm->r0kh_id_len ||
444	    os_memcmp(parse.r0kh_id, sm->r0kh_id, parse.r0kh_id_len) != 0) {
445		wpa_printf(MSG_DEBUG, "FT: R0KH-ID in FTIE did not match with "
446			   "the current R0KH-ID");
447		wpa_hexdump(MSG_DEBUG, "FT: R0KH-ID in FTIE",
448			    parse.r0kh_id, parse.r0kh_id_len);
449		wpa_hexdump(MSG_DEBUG, "FT: The current R0KH-ID",
450			    sm->r0kh_id, sm->r0kh_id_len);
451		return -1;
452	}
453
454	if (parse.r1kh_id == NULL) {
455		wpa_printf(MSG_DEBUG, "FT: No R1KH-ID subelem in FTIE");
456		return -1;
457	}
458
459	if (parse.rsn_pmkid == NULL ||
460	    os_memcmp(parse.rsn_pmkid, sm->pmk_r0_name, WPA_PMK_NAME_LEN)) {
461		wpa_printf(MSG_DEBUG, "FT: No matching PMKR0Name (PMKID) in "
462			   "RSNIE");
463		return -1;
464	}
465
466	os_memcpy(sm->r1kh_id, parse.r1kh_id, FT_R1KH_ID_LEN);
467	wpa_hexdump(MSG_DEBUG, "FT: R1KH-ID", sm->r1kh_id, FT_R1KH_ID_LEN);
468	wpa_hexdump(MSG_DEBUG, "FT: SNonce", sm->snonce, WPA_NONCE_LEN);
469	wpa_hexdump(MSG_DEBUG, "FT: ANonce", ftie->anonce, WPA_NONCE_LEN);
470	os_memcpy(sm->anonce, ftie->anonce, WPA_NONCE_LEN);
471	wpa_derive_pmk_r1(sm->pmk_r0, sm->pmk_r0_name, sm->r1kh_id,
472			  sm->own_addr, sm->pmk_r1, sm->pmk_r1_name);
473	wpa_hexdump_key(MSG_DEBUG, "FT: PMK-R1", sm->pmk_r1, PMK_LEN);
474	wpa_hexdump(MSG_DEBUG, "FT: PMKR1Name",
475		    sm->pmk_r1_name, WPA_PMK_NAME_LEN);
476
477	bssid = target_ap;
478	ptk_len = sm->pairwise_cipher != WPA_CIPHER_TKIP ? 48 : 64;
479	wpa_pmk_r1_to_ptk(sm->pmk_r1, sm->snonce, ftie->anonce, sm->own_addr,
480			  bssid, sm->pmk_r1_name,
481			  (u8 *) &sm->ptk, ptk_len, ptk_name);
482	wpa_hexdump_key(MSG_DEBUG, "FT: PTK",
483			(u8 *) &sm->ptk, ptk_len);
484	wpa_hexdump(MSG_DEBUG, "FT: PTKName", ptk_name, WPA_PMK_NAME_LEN);
485
486	ft_ies = wpa_ft_gen_req_ies(sm, &ft_ies_len, ftie->anonce,
487				    sm->pmk_r1_name, sm->ptk.kck, bssid,
488				    ric_ies, ric_ies_len,
489				    parse.mdie ? parse.mdie - 2 : NULL);
490	if (ft_ies) {
491		wpa_sm_update_ft_ies(sm, sm->mobility_domain,
492				     ft_ies, ft_ies_len);
493		os_free(ft_ies);
494	}
495
496	wpa_sm_mark_authenticated(sm, bssid);
497	ret = wpa_ft_install_ptk(sm, bssid);
498	if (ret) {
499		/*
500		 * Some drivers do not support key configuration when we are
501		 * not associated with the target AP. Work around this by
502		 * trying again after the following reassociation gets
503		 * completed.
504		 */
505		wpa_printf(MSG_DEBUG, "FT: Failed to set PTK prior to "
506			   "association - try again after reassociation");
507		sm->set_ptk_after_assoc = 1;
508	} else
509		sm->set_ptk_after_assoc = 0;
510
511	sm->ft_completed = 1;
512	if (ft_action) {
513		/*
514		 * The caller is expected trigger re-association with the
515		 * Target AP.
516		 */
517		os_memcpy(sm->bssid, target_ap, ETH_ALEN);
518	}
519
520	return 0;
521}
522
523
524int wpa_ft_is_completed(struct wpa_sm *sm)
525{
526	if (sm == NULL)
527		return 0;
528
529	if (sm->key_mgmt != WPA_KEY_MGMT_FT_IEEE8021X &&
530	    sm->key_mgmt != WPA_KEY_MGMT_FT_PSK)
531		return 0;
532
533	return sm->ft_completed;
534}
535
536
537void wpa_reset_ft_completed(struct wpa_sm *sm)
538{
539	if (sm != NULL)
540		sm->ft_completed = 0;
541}
542
543
544static int wpa_ft_process_gtk_subelem(struct wpa_sm *sm, const u8 *gtk_elem,
545				      size_t gtk_elem_len)
546{
547	u8 gtk[32];
548	int keyidx;
549	enum wpa_alg alg;
550	size_t gtk_len, keylen, rsc_len;
551
552	if (gtk_elem == NULL) {
553		wpa_printf(MSG_DEBUG, "FT: No GTK included in FTIE");
554		return 0;
555	}
556
557	wpa_hexdump_key(MSG_DEBUG, "FT: Received GTK in Reassoc Resp",
558			gtk_elem, gtk_elem_len);
559
560	if (gtk_elem_len < 11 + 24 || (gtk_elem_len - 11) % 8 ||
561	    gtk_elem_len - 19 > sizeof(gtk)) {
562		wpa_printf(MSG_DEBUG, "FT: Invalid GTK sub-elem "
563			   "length %lu", (unsigned long) gtk_elem_len);
564		return -1;
565	}
566	gtk_len = gtk_elem_len - 19;
567	if (aes_unwrap(sm->ptk.kek, gtk_len / 8, gtk_elem + 11, gtk)) {
568		wpa_printf(MSG_WARNING, "FT: AES unwrap failed - could not "
569			   "decrypt GTK");
570		return -1;
571	}
572
573	keylen = wpa_cipher_key_len(sm->group_cipher);
574	rsc_len = wpa_cipher_rsc_len(sm->group_cipher);
575	alg = wpa_cipher_to_alg(sm->group_cipher);
576	if (alg == WPA_ALG_NONE) {
577		wpa_printf(MSG_WARNING, "WPA: Unsupported Group Cipher %d",
578			   sm->group_cipher);
579		return -1;
580	}
581
582	if (gtk_len < keylen) {
583		wpa_printf(MSG_DEBUG, "FT: Too short GTK in FTIE");
584		return -1;
585	}
586
587	/* Key Info[2] | Key Length[1] | RSC[8] | Key[5..32]. */
588
589	keyidx = WPA_GET_LE16(gtk_elem) & 0x03;
590
591	if (gtk_elem[2] != keylen) {
592		wpa_printf(MSG_DEBUG, "FT: GTK length mismatch: received %d "
593			   "negotiated %lu",
594			   gtk_elem[2], (unsigned long) keylen);
595		return -1;
596	}
597
598	wpa_hexdump_key(MSG_DEBUG, "FT: GTK from Reassoc Resp", gtk, keylen);
599	if (sm->group_cipher == WPA_CIPHER_TKIP) {
600		/* Swap Tx/Rx keys for Michael MIC */
601		u8 tmp[8];
602		os_memcpy(tmp, gtk + 16, 8);
603		os_memcpy(gtk + 16, gtk + 24, 8);
604		os_memcpy(gtk + 24, tmp, 8);
605	}
606	if (wpa_sm_set_key(sm, alg, broadcast_ether_addr, keyidx, 0,
607			   gtk_elem + 3, rsc_len, gtk, keylen) < 0) {
608		wpa_printf(MSG_WARNING, "WPA: Failed to set GTK to the "
609			   "driver.");
610		return -1;
611	}
612
613	return 0;
614}
615
616
617#ifdef CONFIG_IEEE80211W
618static int wpa_ft_process_igtk_subelem(struct wpa_sm *sm, const u8 *igtk_elem,
619				       size_t igtk_elem_len)
620{
621	u8 igtk[WPA_IGTK_LEN];
622	u16 keyidx;
623
624	if (sm->mgmt_group_cipher != WPA_CIPHER_AES_128_CMAC)
625		return 0;
626
627	if (igtk_elem == NULL) {
628		wpa_printf(MSG_DEBUG, "FT: No IGTK included in FTIE");
629		return 0;
630	}
631
632	wpa_hexdump_key(MSG_DEBUG, "FT: Received IGTK in Reassoc Resp",
633			igtk_elem, igtk_elem_len);
634
635	if (igtk_elem_len != 2 + 6 + 1 + WPA_IGTK_LEN + 8) {
636		wpa_printf(MSG_DEBUG, "FT: Invalid IGTK sub-elem "
637			   "length %lu", (unsigned long) igtk_elem_len);
638		return -1;
639	}
640	if (igtk_elem[8] != WPA_IGTK_LEN) {
641		wpa_printf(MSG_DEBUG, "FT: Invalid IGTK sub-elem Key Length "
642			   "%d", igtk_elem[8]);
643		return -1;
644	}
645
646	if (aes_unwrap(sm->ptk.kek, WPA_IGTK_LEN / 8, igtk_elem + 9, igtk)) {
647		wpa_printf(MSG_WARNING, "FT: AES unwrap failed - could not "
648			   "decrypt IGTK");
649		return -1;
650	}
651
652	/* KeyID[2] | IPN[6] | Key Length[1] | Key[16+8] */
653
654	keyidx = WPA_GET_LE16(igtk_elem);
655
656	wpa_hexdump_key(MSG_DEBUG, "FT: IGTK from Reassoc Resp", igtk,
657			WPA_IGTK_LEN);
658	if (wpa_sm_set_key(sm, WPA_ALG_IGTK, broadcast_ether_addr, keyidx, 0,
659			   igtk_elem + 2, 6, igtk, WPA_IGTK_LEN) < 0) {
660		wpa_printf(MSG_WARNING, "WPA: Failed to set IGTK to the "
661			   "driver.");
662		return -1;
663	}
664
665	return 0;
666}
667#endif /* CONFIG_IEEE80211W */
668
669
670int wpa_ft_validate_reassoc_resp(struct wpa_sm *sm, const u8 *ies,
671				 size_t ies_len, const u8 *src_addr)
672{
673	struct wpa_ft_ies parse;
674	struct rsn_mdie *mdie;
675	struct rsn_ftie *ftie;
676	unsigned int count;
677	u8 mic[16];
678
679	wpa_hexdump(MSG_DEBUG, "FT: Response IEs", ies, ies_len);
680
681	if (sm->key_mgmt != WPA_KEY_MGMT_FT_IEEE8021X &&
682	    sm->key_mgmt != WPA_KEY_MGMT_FT_PSK) {
683		wpa_printf(MSG_DEBUG, "FT: Reject FT IEs since FT is not "
684			   "enabled for this connection");
685		return -1;
686	}
687
688	if (wpa_ft_parse_ies(ies, ies_len, &parse) < 0) {
689		wpa_printf(MSG_DEBUG, "FT: Failed to parse IEs");
690		return -1;
691	}
692
693	mdie = (struct rsn_mdie *) parse.mdie;
694	if (mdie == NULL || parse.mdie_len < sizeof(*mdie) ||
695	    os_memcmp(mdie->mobility_domain, sm->mobility_domain,
696		      MOBILITY_DOMAIN_ID_LEN) != 0) {
697		wpa_printf(MSG_DEBUG, "FT: Invalid MDIE");
698		return -1;
699	}
700
701	ftie = (struct rsn_ftie *) parse.ftie;
702	if (ftie == NULL || parse.ftie_len < sizeof(*ftie)) {
703		wpa_printf(MSG_DEBUG, "FT: Invalid FTIE");
704		return -1;
705	}
706
707	if (os_memcmp(ftie->snonce, sm->snonce, WPA_NONCE_LEN) != 0) {
708		wpa_printf(MSG_DEBUG, "FT: SNonce mismatch in FTIE");
709		wpa_hexdump(MSG_DEBUG, "FT: Received SNonce",
710			    ftie->snonce, WPA_NONCE_LEN);
711		wpa_hexdump(MSG_DEBUG, "FT: Expected SNonce",
712			    sm->snonce, WPA_NONCE_LEN);
713		return -1;
714	}
715
716	if (os_memcmp(ftie->anonce, sm->anonce, WPA_NONCE_LEN) != 0) {
717		wpa_printf(MSG_DEBUG, "FT: ANonce mismatch in FTIE");
718		wpa_hexdump(MSG_DEBUG, "FT: Received ANonce",
719			    ftie->anonce, WPA_NONCE_LEN);
720		wpa_hexdump(MSG_DEBUG, "FT: Expected ANonce",
721			    sm->anonce, WPA_NONCE_LEN);
722		return -1;
723	}
724
725	if (parse.r0kh_id == NULL) {
726		wpa_printf(MSG_DEBUG, "FT: No R0KH-ID subelem in FTIE");
727		return -1;
728	}
729
730	if (parse.r0kh_id_len != sm->r0kh_id_len ||
731	    os_memcmp(parse.r0kh_id, sm->r0kh_id, parse.r0kh_id_len) != 0) {
732		wpa_printf(MSG_DEBUG, "FT: R0KH-ID in FTIE did not match with "
733			   "the current R0KH-ID");
734		wpa_hexdump(MSG_DEBUG, "FT: R0KH-ID in FTIE",
735			    parse.r0kh_id, parse.r0kh_id_len);
736		wpa_hexdump(MSG_DEBUG, "FT: The current R0KH-ID",
737			    sm->r0kh_id, sm->r0kh_id_len);
738		return -1;
739	}
740
741	if (parse.r1kh_id == NULL) {
742		wpa_printf(MSG_DEBUG, "FT: No R1KH-ID subelem in FTIE");
743		return -1;
744	}
745
746	if (os_memcmp(parse.r1kh_id, sm->r1kh_id, FT_R1KH_ID_LEN) != 0) {
747		wpa_printf(MSG_DEBUG, "FT: Unknown R1KH-ID used in "
748			   "ReassocResp");
749		return -1;
750	}
751
752	if (parse.rsn_pmkid == NULL ||
753	    os_memcmp(parse.rsn_pmkid, sm->pmk_r1_name, WPA_PMK_NAME_LEN)) {
754		wpa_printf(MSG_DEBUG, "FT: No matching PMKR1Name (PMKID) in "
755			   "RSNIE (pmkid=%d)", !!parse.rsn_pmkid);
756		return -1;
757	}
758
759	count = 3;
760	if (parse.ric)
761		count += ieee802_11_ie_count(parse.ric, parse.ric_len);
762	if (ftie->mic_control[1] != count) {
763		wpa_printf(MSG_DEBUG, "FT: Unexpected IE count in MIC "
764			   "Control: received %u expected %u",
765			   ftie->mic_control[1], count);
766		return -1;
767	}
768
769	if (wpa_ft_mic(sm->ptk.kck, sm->own_addr, src_addr, 6,
770		       parse.mdie - 2, parse.mdie_len + 2,
771		       parse.ftie - 2, parse.ftie_len + 2,
772		       parse.rsn - 2, parse.rsn_len + 2,
773		       parse.ric, parse.ric_len,
774		       mic) < 0) {
775		wpa_printf(MSG_DEBUG, "FT: Failed to calculate MIC");
776		return -1;
777	}
778
779	if (os_memcmp(mic, ftie->mic, 16) != 0) {
780		wpa_printf(MSG_DEBUG, "FT: Invalid MIC in FTIE");
781		wpa_hexdump(MSG_MSGDUMP, "FT: Received MIC", ftie->mic, 16);
782		wpa_hexdump(MSG_MSGDUMP, "FT: Calculated MIC", mic, 16);
783		return -1;
784	}
785
786	if (wpa_ft_process_gtk_subelem(sm, parse.gtk, parse.gtk_len) < 0)
787		return -1;
788
789#ifdef CONFIG_IEEE80211W
790	if (wpa_ft_process_igtk_subelem(sm, parse.igtk, parse.igtk_len) < 0)
791		return -1;
792#endif /* CONFIG_IEEE80211W */
793
794	if (sm->set_ptk_after_assoc) {
795		wpa_printf(MSG_DEBUG, "FT: Try to set PTK again now that we "
796			   "are associated");
797		if (wpa_ft_install_ptk(sm, src_addr) < 0)
798			return -1;
799		sm->set_ptk_after_assoc = 0;
800	}
801
802	if (parse.ric) {
803		wpa_hexdump(MSG_MSGDUMP, "FT: RIC Response",
804			    parse.ric, parse.ric_len);
805		/* TODO: parse response and inform driver about results when
806		 * using wpa_supplicant SME */
807	}
808
809	wpa_printf(MSG_DEBUG, "FT: Completed successfully");
810
811	return 0;
812}
813
814
815/**
816 * wpa_ft_start_over_ds - Generate over-the-DS auth request
817 * @sm: Pointer to WPA state machine data from wpa_sm_init()
818 * @target_ap: Target AP Address
819 * @mdie: Mobility Domain IE from the target AP
820 * Returns: 0 on success, -1 on failure
821 */
822int wpa_ft_start_over_ds(struct wpa_sm *sm, const u8 *target_ap,
823			 const u8 *mdie)
824{
825	u8 *ft_ies;
826	size_t ft_ies_len;
827
828	wpa_printf(MSG_DEBUG, "FT: Request over-the-DS with " MACSTR,
829		   MAC2STR(target_ap));
830
831	/* Generate a new SNonce */
832	if (random_get_bytes(sm->snonce, WPA_NONCE_LEN)) {
833		wpa_printf(MSG_INFO, "FT: Failed to generate a new SNonce");
834		return -1;
835	}
836
837	ft_ies = wpa_ft_gen_req_ies(sm, &ft_ies_len, NULL, sm->pmk_r0_name,
838				    NULL, target_ap, NULL, 0, mdie);
839	if (ft_ies) {
840		sm->over_the_ds_in_progress = 1;
841		os_memcpy(sm->target_ap, target_ap, ETH_ALEN);
842		wpa_sm_send_ft_action(sm, 1, target_ap, ft_ies, ft_ies_len);
843		os_free(ft_ies);
844	}
845
846	return 0;
847}
848
849#endif /* CONFIG_IEEE80211R */
850