Line data Source code
1 : /*
2 : * WPA Supplicant - Mesh RSN routines
3 : * Copyright (c) 2013-2014, cozybit, Inc. All rights reserved.
4 : *
5 : * This software may be distributed under the terms of the BSD license.
6 : * See README for more details.
7 : */
8 :
9 : #include "utils/includes.h"
10 :
11 : #include "utils/common.h"
12 : #include "utils/eloop.h"
13 : #include "crypto/sha256.h"
14 : #include "crypto/random.h"
15 : #include "crypto/aes.h"
16 : #include "crypto/aes_siv.h"
17 : #include "rsn_supp/wpa.h"
18 : #include "ap/hostapd.h"
19 : #include "ap/wpa_auth.h"
20 : #include "ap/sta_info.h"
21 : #include "ap/ieee802_11.h"
22 : #include "wpa_supplicant_i.h"
23 : #include "driver_i.h"
24 : #include "wpas_glue.h"
25 : #include "mesh_mpm.h"
26 : #include "mesh_rsn.h"
27 :
28 : #define MESH_AUTH_TIMEOUT 10
29 : #define MESH_AUTH_RETRY 3
30 :
31 12 : void mesh_auth_timer(void *eloop_ctx, void *user_data)
32 : {
33 12 : struct wpa_supplicant *wpa_s = eloop_ctx;
34 12 : struct sta_info *sta = user_data;
35 : struct hostapd_data *hapd;
36 :
37 12 : if (sta->sae->state != SAE_ACCEPTED) {
38 84 : wpa_printf(MSG_DEBUG, "AUTH: Re-authenticate with " MACSTR
39 : " (attempt %d) ",
40 84 : MAC2STR(sta->addr), sta->sae_auth_retry);
41 72 : wpa_msg(wpa_s, MSG_INFO, MESH_SAE_AUTH_FAILURE "addr=" MACSTR,
42 72 : MAC2STR(sta->addr));
43 12 : if (sta->sae_auth_retry < MESH_AUTH_RETRY) {
44 10 : mesh_rsn_auth_sae_sta(wpa_s, sta);
45 : } else {
46 2 : hapd = wpa_s->ifmsh->bss[0];
47 :
48 2 : if (sta->sae_auth_retry > MESH_AUTH_RETRY) {
49 0 : ap_free_sta(hapd, sta);
50 12 : return;
51 : }
52 :
53 : /* block the STA if exceeded the number of attempts */
54 2 : wpa_mesh_set_plink_state(wpa_s, sta, PLINK_BLOCKED);
55 2 : sta->sae->state = SAE_NOTHING;
56 14 : wpa_msg(wpa_s, MSG_INFO, MESH_SAE_AUTH_BLOCKED "addr="
57 : MACSTR " duration=%d",
58 12 : MAC2STR(sta->addr),
59 2 : hapd->conf->ap_max_inactivity);
60 : }
61 12 : sta->sae_auth_retry++;
62 : }
63 : }
64 :
65 :
66 72 : static void auth_logger(void *ctx, const u8 *addr, logger_level level,
67 : const char *txt)
68 : {
69 72 : if (addr)
70 432 : wpa_printf(MSG_DEBUG, "AUTH: " MACSTR " - %s",
71 432 : MAC2STR(addr), txt);
72 : else
73 0 : wpa_printf(MSG_DEBUG, "AUTH: %s", txt);
74 72 : }
75 :
76 :
77 0 : static const u8 *auth_get_psk(void *ctx, const u8 *addr,
78 : const u8 *p2p_dev_addr, const u8 *prev_psk)
79 : {
80 0 : struct mesh_rsn *mesh_rsn = ctx;
81 0 : struct hostapd_data *hapd = mesh_rsn->wpa_s->ifmsh->bss[0];
82 0 : struct sta_info *sta = ap_get_sta(hapd, addr);
83 :
84 0 : wpa_printf(MSG_DEBUG, "AUTH: %s (addr=" MACSTR " prev_psk=%p)",
85 0 : __func__, MAC2STR(addr), prev_psk);
86 :
87 0 : if (sta && sta->auth_alg == WLAN_AUTH_SAE) {
88 0 : if (!sta->sae || prev_psk)
89 0 : return NULL;
90 0 : return sta->sae->pmk;
91 : }
92 :
93 0 : return NULL;
94 : }
95 :
96 :
97 54 : static int auth_set_key(void *ctx, int vlan_id, enum wpa_alg alg,
98 : const u8 *addr, int idx, u8 *key, size_t key_len)
99 : {
100 54 : struct mesh_rsn *mesh_rsn = ctx;
101 : u8 seq[6];
102 :
103 54 : os_memset(seq, 0, sizeof(seq));
104 :
105 54 : if (addr) {
106 324 : wpa_printf(MSG_DEBUG, "AUTH: %s(alg=%d addr=" MACSTR
107 : " key_idx=%d)",
108 324 : __func__, alg, MAC2STR(addr), idx);
109 : } else {
110 0 : wpa_printf(MSG_DEBUG, "AUTH: %s(alg=%d key_idx=%d)",
111 : __func__, alg, idx);
112 : }
113 54 : wpa_hexdump_key(MSG_DEBUG, "AUTH: set_key - key", key, key_len);
114 :
115 54 : return wpa_drv_set_key(mesh_rsn->wpa_s, alg, addr, idx,
116 : 1, seq, 6, key, key_len);
117 : }
118 :
119 :
120 72 : static int auth_start_ampe(void *ctx, const u8 *addr)
121 : {
122 72 : struct mesh_rsn *mesh_rsn = ctx;
123 : struct hostapd_data *hapd;
124 : struct sta_info *sta;
125 :
126 72 : if (mesh_rsn->wpa_s->current_ssid->mode != WPAS_MODE_MESH)
127 0 : return -1;
128 :
129 72 : hapd = mesh_rsn->wpa_s->ifmsh->bss[0];
130 72 : sta = ap_get_sta(hapd, addr);
131 72 : if (sta)
132 72 : eloop_cancel_timeout(mesh_auth_timer, mesh_rsn->wpa_s, sta);
133 :
134 72 : mesh_mpm_auth_peer(mesh_rsn->wpa_s, addr);
135 72 : return 0;
136 : }
137 :
138 :
139 68 : static int __mesh_rsn_auth_init(struct mesh_rsn *rsn, const u8 *addr,
140 : enum mfp_options ieee80211w)
141 : {
142 : struct wpa_auth_config conf;
143 : struct wpa_auth_callbacks cb;
144 68 : u8 seq[6] = {};
145 :
146 68 : wpa_printf(MSG_DEBUG, "AUTH: Initializing group state machine");
147 :
148 68 : os_memset(&conf, 0, sizeof(conf));
149 68 : conf.wpa = WPA_PROTO_RSN;
150 68 : conf.wpa_key_mgmt = WPA_KEY_MGMT_SAE;
151 68 : conf.wpa_pairwise = rsn->pairwise_cipher;
152 68 : conf.rsn_pairwise = rsn->pairwise_cipher;
153 68 : conf.wpa_group = rsn->group_cipher;
154 68 : conf.eapol_version = 0;
155 68 : conf.wpa_group_rekey = -1;
156 : #ifdef CONFIG_IEEE80211W
157 68 : conf.ieee80211w = ieee80211w;
158 68 : if (ieee80211w != NO_MGMT_FRAME_PROTECTION)
159 4 : conf.group_mgmt_cipher = rsn->mgmt_group_cipher;
160 : #endif /* CONFIG_IEEE80211W */
161 :
162 68 : os_memset(&cb, 0, sizeof(cb));
163 68 : cb.ctx = rsn;
164 68 : cb.logger = auth_logger;
165 68 : cb.get_psk = auth_get_psk;
166 68 : cb.set_key = auth_set_key;
167 68 : cb.start_ampe = auth_start_ampe;
168 :
169 68 : rsn->auth = wpa_init(addr, &conf, &cb);
170 68 : if (rsn->auth == NULL) {
171 1 : wpa_printf(MSG_DEBUG, "AUTH: wpa_init() failed");
172 1 : return -1;
173 : }
174 :
175 : /* TODO: support rekeying */
176 67 : rsn->mgtk_len = wpa_cipher_key_len(conf.wpa_group);
177 67 : if (random_get_bytes(rsn->mgtk, rsn->mgtk_len) < 0)
178 1 : return -1;
179 66 : rsn->mgtk_key_id = 1;
180 :
181 : #ifdef CONFIG_IEEE80211W
182 66 : if (ieee80211w != NO_MGMT_FRAME_PROTECTION) {
183 4 : rsn->igtk_len = wpa_cipher_key_len(conf.group_mgmt_cipher);
184 4 : if (random_get_bytes(rsn->igtk, rsn->igtk_len) < 0)
185 0 : return -1;
186 4 : rsn->igtk_key_id = 4;
187 :
188 : /* group mgmt */
189 8 : wpa_hexdump_key(MSG_DEBUG, "mesh: Own TX IGTK",
190 4 : rsn->igtk, rsn->igtk_len);
191 12 : wpa_drv_set_key(rsn->wpa_s,
192 4 : wpa_cipher_to_alg(rsn->mgmt_group_cipher), NULL,
193 4 : rsn->igtk_key_id, 1,
194 4 : seq, sizeof(seq), rsn->igtk, rsn->igtk_len);
195 : }
196 : #endif /* CONFIG_IEEE80211W */
197 :
198 : /* group privacy / data frames */
199 132 : wpa_hexdump_key(MSG_DEBUG, "mesh: Own TX MGTK",
200 66 : rsn->mgtk, rsn->mgtk_len);
201 132 : wpa_drv_set_key(rsn->wpa_s, wpa_cipher_to_alg(rsn->group_cipher), NULL,
202 66 : rsn->mgtk_key_id, 1, seq, sizeof(seq),
203 66 : rsn->mgtk, rsn->mgtk_len);
204 :
205 66 : return 0;
206 : }
207 :
208 :
209 2 : static void mesh_rsn_deinit(struct mesh_rsn *rsn)
210 : {
211 2 : os_memset(rsn->mgtk, 0, sizeof(rsn->mgtk));
212 2 : rsn->mgtk_len = 0;
213 2 : os_memset(rsn->igtk, 0, sizeof(rsn->igtk));
214 2 : rsn->igtk_len = 0;
215 2 : if (rsn->auth)
216 1 : wpa_deinit(rsn->auth);
217 2 : }
218 :
219 :
220 69 : struct mesh_rsn *mesh_rsn_auth_init(struct wpa_supplicant *wpa_s,
221 : struct mesh_conf *conf)
222 : {
223 : struct mesh_rsn *mesh_rsn;
224 69 : struct hostapd_data *bss = wpa_s->ifmsh->bss[0];
225 : const u8 *ie;
226 : size_t ie_len;
227 :
228 69 : mesh_rsn = os_zalloc(sizeof(*mesh_rsn));
229 69 : if (mesh_rsn == NULL)
230 1 : return NULL;
231 68 : mesh_rsn->wpa_s = wpa_s;
232 68 : mesh_rsn->pairwise_cipher = conf->pairwise_cipher;
233 68 : mesh_rsn->group_cipher = conf->group_cipher;
234 68 : mesh_rsn->mgmt_group_cipher = conf->mgmt_group_cipher;
235 :
236 68 : if (__mesh_rsn_auth_init(mesh_rsn, wpa_s->own_addr,
237 : conf->ieee80211w) < 0) {
238 2 : mesh_rsn_deinit(mesh_rsn);
239 2 : os_free(mesh_rsn);
240 2 : return NULL;
241 : }
242 :
243 66 : bss->wpa_auth = mesh_rsn->auth;
244 :
245 66 : ie = wpa_auth_get_wpa_ie(mesh_rsn->auth, &ie_len);
246 66 : conf->rsn_ie = (u8 *) ie;
247 66 : conf->rsn_ie_len = ie_len;
248 :
249 66 : wpa_supplicant_rsn_supp_set_config(wpa_s, wpa_s->current_ssid);
250 :
251 66 : return mesh_rsn;
252 : }
253 :
254 :
255 83 : static int index_within_array(const int *array, int idx)
256 : {
257 : int i;
258 :
259 86 : for (i = 0; i < idx; i++) {
260 3 : if (array[i] == -1)
261 0 : return 0;
262 : }
263 :
264 83 : return 1;
265 : }
266 :
267 :
268 83 : static int mesh_rsn_sae_group(struct wpa_supplicant *wpa_s,
269 : struct sae_data *sae)
270 : {
271 83 : int *groups = wpa_s->ifmsh->bss[0]->conf->sae_groups;
272 :
273 : /* Configuration may have changed, so validate current index */
274 83 : if (!index_within_array(groups, wpa_s->mesh_rsn->sae_group_index))
275 0 : return -1;
276 :
277 : for (;;) {
278 87 : int group = groups[wpa_s->mesh_rsn->sae_group_index];
279 :
280 87 : if (group <= 0)
281 2 : break;
282 85 : if (sae_set_group(sae, group) == 0) {
283 81 : wpa_dbg(wpa_s, MSG_DEBUG, "SME: Selected SAE group %d",
284 : sae->group);
285 81 : return 0;
286 : }
287 4 : wpa_s->mesh_rsn->sae_group_index++;
288 4 : }
289 :
290 2 : return -1;
291 : }
292 :
293 :
294 83 : static int mesh_rsn_build_sae_commit(struct wpa_supplicant *wpa_s,
295 : struct wpa_ssid *ssid,
296 : struct sta_info *sta)
297 : {
298 83 : if (ssid->passphrase == NULL) {
299 0 : wpa_msg(wpa_s, MSG_DEBUG, "SAE: No password available");
300 0 : return -1;
301 : }
302 :
303 83 : if (mesh_rsn_sae_group(wpa_s, sta->sae) < 0) {
304 2 : wpa_msg(wpa_s, MSG_DEBUG, "SAE: Failed to select group");
305 2 : return -1;
306 : }
307 :
308 243 : return sae_prepare_commit(wpa_s->own_addr, sta->addr,
309 81 : (u8 *) ssid->passphrase,
310 81 : os_strlen(ssid->passphrase), sta->sae);
311 : }
312 :
313 :
314 : /* initiate new SAE authentication with sta */
315 93 : int mesh_rsn_auth_sae_sta(struct wpa_supplicant *wpa_s,
316 : struct sta_info *sta)
317 : {
318 93 : struct hostapd_data *hapd = wpa_s->ifmsh->bss[0];
319 93 : struct wpa_ssid *ssid = wpa_s->current_ssid;
320 : struct rsn_pmksa_cache_entry *pmksa;
321 : unsigned int rnd;
322 : int ret;
323 :
324 93 : if (!ssid) {
325 0 : wpa_msg(wpa_s, MSG_DEBUG,
326 : "AUTH: No current_ssid known to initiate new SAE");
327 0 : return -1;
328 : }
329 :
330 93 : if (!sta->sae) {
331 83 : sta->sae = os_zalloc(sizeof(*sta->sae));
332 83 : if (sta->sae == NULL)
333 1 : return -1;
334 : }
335 :
336 92 : pmksa = wpa_auth_pmksa_get(hapd->wpa_auth, sta->addr);
337 92 : if (pmksa) {
338 9 : if (!sta->wpa_sm)
339 9 : sta->wpa_sm = wpa_auth_sta_init(hapd->wpa_auth,
340 9 : sta->addr, NULL);
341 9 : if (!sta->wpa_sm) {
342 1 : wpa_printf(MSG_ERROR,
343 : "mesh: Failed to initialize RSN state machine");
344 1 : return -1;
345 : }
346 :
347 48 : wpa_printf(MSG_DEBUG,
348 : "AUTH: Mesh PMKSA cache entry found for " MACSTR
349 : " - try to use PMKSA caching instead of new SAE authentication",
350 48 : MAC2STR(sta->addr));
351 8 : wpa_auth_pmksa_set_to_sm(pmksa, sta->wpa_sm, hapd->wpa_auth,
352 8 : sta->sae->pmkid, sta->sae->pmk);
353 8 : sae_accept_sta(hapd, sta);
354 8 : sta->mesh_sae_pmksa_caching = 1;
355 8 : return 0;
356 : }
357 83 : sta->mesh_sae_pmksa_caching = 0;
358 :
359 83 : if (mesh_rsn_build_sae_commit(wpa_s, ssid, sta))
360 2 : return -1;
361 :
362 486 : wpa_msg(wpa_s, MSG_DEBUG,
363 : "AUTH: started authentication with SAE peer: " MACSTR,
364 486 : MAC2STR(sta->addr));
365 :
366 81 : ret = auth_sae_init_committed(hapd, sta);
367 81 : if (ret)
368 1 : return ret;
369 :
370 80 : eloop_cancel_timeout(mesh_auth_timer, wpa_s, sta);
371 80 : rnd = rand() % MESH_AUTH_TIMEOUT;
372 80 : eloop_register_timeout(MESH_AUTH_TIMEOUT + rnd, 0, mesh_auth_timer,
373 : wpa_s, sta);
374 80 : return 0;
375 : }
376 :
377 :
378 262 : void mesh_rsn_get_pmkid(struct mesh_rsn *rsn, struct sta_info *sta, u8 *pmkid)
379 : {
380 262 : os_memcpy(pmkid, sta->sae->pmkid, SAE_PMKID_LEN);
381 262 : }
382 :
383 :
384 : static void
385 72 : mesh_rsn_derive_aek(struct mesh_rsn *rsn, struct sta_info *sta)
386 : {
387 72 : u8 *myaddr = rsn->wpa_s->own_addr;
388 72 : u8 *peer = sta->addr;
389 : u8 *addr1, *addr2;
390 72 : u8 context[RSN_SELECTOR_LEN + 2 * ETH_ALEN], *ptr = context;
391 :
392 : /*
393 : * AEK = KDF-Hash-256(PMK, "AEK Derivation", Selected AKM Suite ||
394 : * min(localMAC, peerMAC) || max(localMAC, peerMAC))
395 : */
396 : /* Selected AKM Suite: SAE */
397 72 : RSN_SELECTOR_PUT(ptr, RSN_AUTH_KEY_MGMT_SAE);
398 72 : ptr += RSN_SELECTOR_LEN;
399 :
400 72 : if (os_memcmp(myaddr, peer, ETH_ALEN) < 0) {
401 36 : addr1 = myaddr;
402 36 : addr2 = peer;
403 : } else {
404 36 : addr1 = peer;
405 36 : addr2 = myaddr;
406 : }
407 72 : os_memcpy(ptr, addr1, ETH_ALEN);
408 72 : ptr += ETH_ALEN;
409 72 : os_memcpy(ptr, addr2, ETH_ALEN);
410 :
411 72 : sha256_prf(sta->sae->pmk, sizeof(sta->sae->pmk), "AEK Derivation",
412 72 : context, sizeof(context), sta->aek, sizeof(sta->aek));
413 72 : }
414 :
415 :
416 : /* derive mesh temporal key from pmk */
417 68 : int mesh_rsn_derive_mtk(struct wpa_supplicant *wpa_s, struct sta_info *sta)
418 : {
419 : u8 *ptr;
420 : u8 *min, *max;
421 68 : u8 *myaddr = wpa_s->own_addr;
422 68 : u8 *peer = sta->addr;
423 : u8 context[2 * WPA_NONCE_LEN + 2 * 2 + RSN_SELECTOR_LEN + 2 * ETH_ALEN];
424 :
425 : /*
426 : * MTK = KDF-Hash-Length(PMK, "Temporal Key Derivation", min(localNonce,
427 : * peerNonce) || max(localNonce, peerNonce) || min(localLinkID,
428 : * peerLinkID) || max(localLinkID, peerLinkID) || Selected AKM Suite ||
429 : * min(localMAC, peerMAC) || max(localMAC, peerMAC))
430 : */
431 68 : ptr = context;
432 68 : if (os_memcmp(sta->my_nonce, sta->peer_nonce, WPA_NONCE_LEN) < 0) {
433 34 : min = sta->my_nonce;
434 34 : max = sta->peer_nonce;
435 : } else {
436 34 : min = sta->peer_nonce;
437 34 : max = sta->my_nonce;
438 : }
439 68 : os_memcpy(ptr, min, WPA_NONCE_LEN);
440 68 : ptr += WPA_NONCE_LEN;
441 68 : os_memcpy(ptr, max, WPA_NONCE_LEN);
442 68 : ptr += WPA_NONCE_LEN;
443 :
444 68 : if (sta->my_lid < sta->peer_lid) {
445 34 : WPA_PUT_LE16(ptr, sta->my_lid);
446 34 : ptr += 2;
447 34 : WPA_PUT_LE16(ptr, sta->peer_lid);
448 34 : ptr += 2;
449 : } else {
450 34 : WPA_PUT_LE16(ptr, sta->peer_lid);
451 34 : ptr += 2;
452 34 : WPA_PUT_LE16(ptr, sta->my_lid);
453 34 : ptr += 2;
454 : }
455 :
456 : /* Selected AKM Suite: SAE */
457 68 : RSN_SELECTOR_PUT(ptr, RSN_AUTH_KEY_MGMT_SAE);
458 68 : ptr += RSN_SELECTOR_LEN;
459 :
460 68 : if (os_memcmp(myaddr, peer, ETH_ALEN) < 0) {
461 34 : min = myaddr;
462 34 : max = peer;
463 : } else {
464 34 : min = peer;
465 34 : max = myaddr;
466 : }
467 68 : os_memcpy(ptr, min, ETH_ALEN);
468 68 : ptr += ETH_ALEN;
469 68 : os_memcpy(ptr, max, ETH_ALEN);
470 :
471 68 : sta->mtk_len = wpa_cipher_key_len(wpa_s->mesh_rsn->pairwise_cipher);
472 136 : sha256_prf(sta->sae->pmk, SAE_PMK_LEN,
473 : "Temporal Key Derivation", context, sizeof(context),
474 68 : sta->mtk, sta->mtk_len);
475 68 : return 0;
476 : }
477 :
478 :
479 72 : void mesh_rsn_init_ampe_sta(struct wpa_supplicant *wpa_s, struct sta_info *sta)
480 : {
481 72 : if (random_get_bytes(sta->my_nonce, WPA_NONCE_LEN) < 0) {
482 1 : wpa_printf(MSG_INFO, "mesh: Failed to derive random nonce");
483 : /* TODO: How to handle this more cleanly? */
484 : }
485 72 : os_memset(sta->peer_nonce, 0, WPA_NONCE_LEN);
486 72 : mesh_rsn_derive_aek(wpa_s->mesh_rsn, sta);
487 72 : }
488 :
489 :
490 : /* insert AMPE and encrypted MIC at @ie.
491 : * @mesh_rsn: mesh RSN context
492 : * @sta: STA we're sending to
493 : * @cat: pointer to category code in frame header.
494 : * @buf: wpabuf to add encrypted AMPE and MIC to.
495 : * */
496 262 : int mesh_rsn_protect_frame(struct mesh_rsn *rsn, struct sta_info *sta,
497 : const u8 *cat, struct wpabuf *buf)
498 : {
499 : struct ieee80211_ampe_ie *ampe;
500 262 : u8 const *ie = wpabuf_head_u8(buf) + wpabuf_len(buf);
501 : u8 *ampe_ie, *pos, *mic_payload;
502 262 : const u8 *aad[] = { rsn->wpa_s->own_addr, sta->addr, cat };
503 262 : const size_t aad_len[] = { ETH_ALEN, ETH_ALEN, ie - cat };
504 262 : int ret = 0;
505 : size_t len;
506 :
507 262 : len = sizeof(*ampe);
508 262 : if (cat[1] == PLINK_OPEN)
509 81 : len += rsn->mgtk_len + WPA_KEY_RSC_LEN + 4;
510 : #ifdef CONFIG_IEEE80211W
511 262 : if (cat[1] == PLINK_OPEN && rsn->igtk_len)
512 4 : len += 2 + 6 + rsn->igtk_len;
513 : #endif /* CONFIG_IEEE80211W */
514 :
515 262 : if (2 + AES_BLOCK_SIZE + 2 + len > wpabuf_tailroom(buf)) {
516 0 : wpa_printf(MSG_ERROR, "protect frame: buffer too small");
517 0 : return -EINVAL;
518 : }
519 :
520 262 : ampe_ie = os_zalloc(2 + len);
521 262 : if (!ampe_ie) {
522 2 : wpa_printf(MSG_ERROR, "protect frame: out of memory");
523 2 : return -ENOMEM;
524 : }
525 :
526 : /* IE: AMPE */
527 260 : ampe_ie[0] = WLAN_EID_AMPE;
528 260 : ampe_ie[1] = len;
529 260 : ampe = (struct ieee80211_ampe_ie *) (ampe_ie + 2);
530 :
531 260 : RSN_SELECTOR_PUT(ampe->selected_pairwise_suite,
532 : RSN_CIPHER_SUITE_CCMP);
533 260 : os_memcpy(ampe->local_nonce, sta->my_nonce, WPA_NONCE_LEN);
534 260 : os_memcpy(ampe->peer_nonce, sta->peer_nonce, WPA_NONCE_LEN);
535 :
536 260 : pos = (u8 *) (ampe + 1);
537 260 : if (cat[1] != PLINK_OPEN)
538 180 : goto skip_keys;
539 :
540 : /* TODO: Key Replay Counter[8] optionally for
541 : * Mesh Group Key Inform/Acknowledge frames */
542 :
543 : /* TODO: static mgtk for now since we don't support rekeying! */
544 : /*
545 : * GTKdata[variable]:
546 : * MGTK[variable] || Key RSC[8] || GTKExpirationTime[4]
547 : */
548 80 : os_memcpy(pos, rsn->mgtk, rsn->mgtk_len);
549 80 : pos += rsn->mgtk_len;
550 80 : wpa_drv_get_seqnum(rsn->wpa_s, NULL, rsn->mgtk_key_id, pos);
551 80 : pos += WPA_KEY_RSC_LEN;
552 : /* Use fixed GTKExpirationTime for now */
553 80 : WPA_PUT_LE32(pos, 0xffffffff);
554 80 : pos += 4;
555 :
556 : #ifdef CONFIG_IEEE80211W
557 : /*
558 : * IGTKdata[variable]:
559 : * Key ID[2], IPN[6], IGTK[variable]
560 : */
561 80 : if (rsn->igtk_len) {
562 4 : WPA_PUT_LE16(pos, rsn->igtk_key_id);
563 4 : pos += 2;
564 4 : wpa_drv_get_seqnum(rsn->wpa_s, NULL, rsn->igtk_key_id, pos);
565 4 : pos += 6;
566 4 : os_memcpy(pos, rsn->igtk, rsn->igtk_len);
567 : }
568 : #endif /* CONFIG_IEEE80211W */
569 :
570 : skip_keys:
571 260 : wpa_hexdump_key(MSG_DEBUG, "mesh: Plaintext AMPE element",
572 : ampe_ie, 2 + len);
573 :
574 : /* IE: MIC */
575 260 : wpabuf_put_u8(buf, WLAN_EID_MIC);
576 260 : wpabuf_put_u8(buf, AES_BLOCK_SIZE);
577 : /* MIC field is output ciphertext */
578 :
579 : /* encrypt after MIC */
580 260 : mic_payload = wpabuf_put(buf, 2 + len + AES_BLOCK_SIZE);
581 :
582 260 : if (aes_siv_encrypt(sta->aek, ampe_ie, 2 + len, 3,
583 : aad, aad_len, mic_payload)) {
584 1 : wpa_printf(MSG_ERROR, "protect frame: failed to encrypt");
585 1 : ret = -ENOMEM;
586 : }
587 :
588 260 : os_free(ampe_ie);
589 :
590 260 : return ret;
591 : }
592 :
593 :
594 187 : int mesh_rsn_process_ampe(struct wpa_supplicant *wpa_s, struct sta_info *sta,
595 : struct ieee802_11_elems *elems, const u8 *cat,
596 : const u8 *chosen_pmk,
597 : const u8 *start, size_t elems_len)
598 : {
599 187 : int ret = 0;
600 : struct ieee80211_ampe_ie *ampe;
601 187 : u8 null_nonce[WPA_NONCE_LEN] = {};
602 : u8 ampe_eid;
603 : u8 ampe_ie_len;
604 187 : u8 *ampe_buf, *crypt = NULL, *pos, *end;
605 : size_t crypt_len;
606 187 : const u8 *aad[] = { sta->addr, wpa_s->own_addr, cat };
607 374 : const size_t aad_len[] = { ETH_ALEN, ETH_ALEN,
608 187 : (elems->mic - 2) - cat };
609 : size_t key_len;
610 :
611 187 : if (!sta->sae) {
612 7 : struct hostapd_data *hapd = wpa_s->ifmsh->bss[0];
613 :
614 7 : if (!wpa_auth_pmksa_get(hapd->wpa_auth, sta->addr)) {
615 4 : wpa_printf(MSG_INFO,
616 : "Mesh RSN: SAE is not prepared yet");
617 4 : return -1;
618 : }
619 3 : mesh_rsn_auth_sae_sta(wpa_s, sta);
620 : }
621 :
622 183 : if (chosen_pmk && os_memcmp(chosen_pmk, sta->sae->pmkid, PMKID_LEN)) {
623 2 : wpa_msg(wpa_s, MSG_DEBUG,
624 : "Mesh RSN: Invalid PMKID (Chosen PMK did not match calculated PMKID)");
625 2 : return -1;
626 : }
627 :
628 181 : if (!elems->mic || elems->mic_len < AES_BLOCK_SIZE) {
629 1 : wpa_msg(wpa_s, MSG_DEBUG, "Mesh RSN: missing mic ie");
630 1 : return -1;
631 : }
632 :
633 180 : ampe_buf = (u8 *) elems->mic + elems->mic_len;
634 180 : if ((int) elems_len < ampe_buf - start)
635 0 : return -1;
636 :
637 180 : crypt_len = elems_len - (elems->mic - start);
638 180 : if (crypt_len < 2 + AES_BLOCK_SIZE) {
639 0 : wpa_msg(wpa_s, MSG_DEBUG, "Mesh RSN: missing ampe ie");
640 0 : return -1;
641 : }
642 :
643 : /* crypt is modified by siv_decrypt */
644 180 : crypt = os_zalloc(crypt_len);
645 180 : if (!crypt) {
646 1 : wpa_printf(MSG_ERROR, "Mesh RSN: out of memory");
647 1 : ret = -ENOMEM;
648 1 : goto free;
649 : }
650 :
651 179 : os_memcpy(crypt, elems->mic, crypt_len);
652 :
653 179 : if (aes_siv_decrypt(sta->aek, crypt, crypt_len, 3,
654 : aad, aad_len, ampe_buf)) {
655 1 : wpa_printf(MSG_ERROR, "Mesh RSN: frame verification failed!");
656 1 : ret = -2;
657 1 : goto free;
658 : }
659 :
660 178 : crypt_len -= AES_BLOCK_SIZE;
661 178 : wpa_hexdump_key(MSG_DEBUG, "mesh: Decrypted AMPE element",
662 : ampe_buf, crypt_len);
663 :
664 178 : ampe_eid = *ampe_buf++;
665 178 : ampe_ie_len = *ampe_buf++;
666 :
667 356 : if (ampe_eid != WLAN_EID_AMPE ||
668 356 : (size_t) 2 + ampe_ie_len > crypt_len ||
669 : ampe_ie_len < sizeof(struct ieee80211_ampe_ie)) {
670 0 : wpa_msg(wpa_s, MSG_DEBUG, "Mesh RSN: invalid ampe ie");
671 0 : ret = -1;
672 0 : goto free;
673 : }
674 :
675 178 : ampe = (struct ieee80211_ampe_ie *) ampe_buf;
676 178 : pos = (u8 *) (ampe + 1);
677 178 : end = ampe_buf + ampe_ie_len;
678 291 : if (os_memcmp(ampe->peer_nonce, null_nonce, WPA_NONCE_LEN) != 0 &&
679 113 : os_memcmp(ampe->peer_nonce, sta->my_nonce, WPA_NONCE_LEN) != 0) {
680 0 : wpa_msg(wpa_s, MSG_DEBUG, "Mesh RSN: invalid peer nonce");
681 0 : ret = -1;
682 0 : goto free;
683 : }
684 178 : os_memcpy(sta->peer_nonce, ampe->local_nonce,
685 : sizeof(ampe->local_nonce));
686 :
687 : /* TODO: Key Replay Counter[8] in Mesh Group Key Inform/Acknowledge
688 : * frames */
689 :
690 : /*
691 : * GTKdata shall not be included in Mesh Peering Confirm. While the
692 : * standard does not state the same about IGTKdata, that same constraint
693 : * needs to apply for it. It makes no sense to include the keys in Mesh
694 : * Peering Close frames either, so while the standard does not seem to
695 : * have a shall statement for these, they are described without
696 : * mentioning GTKdata.
697 : *
698 : * An earlier implementation used to add GTKdata to both Mesh Peering
699 : * Open and Mesh Peering Confirm frames, so ignore the possibly present
700 : * GTKdata frame without rejecting the frame as a backwards
701 : * compatibility mechanism.
702 : */
703 178 : if (cat[1] != PLINK_OPEN) {
704 108 : if (end > pos) {
705 0 : wpa_hexdump_key(MSG_DEBUG,
706 : "mesh: Ignore unexpected GTKdata(etc.) fields in the end of AMPE element in Mesh Peering Confirm/Close",
707 0 : pos, end - pos);
708 : }
709 108 : goto free;
710 : }
711 :
712 : /*
713 : * GTKdata[variable]:
714 : * MGTK[variable] || Key RSC[8] || GTKExpirationTime[4]
715 : */
716 70 : sta->mgtk_key_id = 1; /* FIX: Where to get Key ID? */
717 70 : key_len = wpa_cipher_key_len(wpa_s->mesh_rsn->group_cipher);
718 70 : if ((int) key_len + WPA_KEY_RSC_LEN + 4 > end - pos) {
719 0 : wpa_dbg(wpa_s, MSG_DEBUG, "mesh: Truncated AMPE element");
720 0 : ret = -1;
721 0 : goto free;
722 : }
723 70 : sta->mgtk_len = key_len;
724 70 : os_memcpy(sta->mgtk, pos, sta->mgtk_len);
725 140 : wpa_hexdump_key(MSG_DEBUG, "mesh: GTKdata - MGTK",
726 70 : sta->mgtk, sta->mgtk_len);
727 70 : pos += sta->mgtk_len;
728 70 : wpa_hexdump(MSG_DEBUG, "mesh: GTKdata - MGTK - Key RSC",
729 : pos, WPA_KEY_RSC_LEN);
730 70 : os_memcpy(sta->mgtk_rsc, pos, sizeof(sta->mgtk_rsc));
731 70 : pos += WPA_KEY_RSC_LEN;
732 70 : wpa_printf(MSG_DEBUG,
733 : "mesh: GTKdata - MGTK - GTKExpirationTime: %u seconds",
734 : WPA_GET_LE32(pos));
735 70 : pos += 4;
736 :
737 : #ifdef CONFIG_IEEE80211W
738 : /*
739 : * IGTKdata[variable]:
740 : * Key ID[2], IPN[6], IGTK[variable]
741 : */
742 70 : key_len = wpa_cipher_key_len(wpa_s->mesh_rsn->mgmt_group_cipher);
743 70 : if (end - pos >= (int) (2 + 6 + key_len)) {
744 4 : sta->igtk_key_id = WPA_GET_LE16(pos);
745 4 : wpa_printf(MSG_DEBUG, "mesh: IGTKdata - Key ID %u",
746 4 : sta->igtk_key_id);
747 4 : pos += 2;
748 4 : os_memcpy(sta->igtk_rsc, pos, sizeof(sta->igtk_rsc));
749 4 : wpa_hexdump(MSG_DEBUG, "mesh: IGTKdata - IPN",
750 4 : sta->igtk_rsc, sizeof(sta->igtk_rsc));
751 4 : pos += 6;
752 4 : os_memcpy(sta->igtk, pos, key_len);
753 4 : sta->igtk_len = key_len;
754 8 : wpa_hexdump_key(MSG_DEBUG, "mesh: IGTKdata - IGTK",
755 4 : sta->igtk, sta->igtk_len);
756 : }
757 : #endif /* CONFIG_IEEE80211W */
758 :
759 : free:
760 180 : os_free(crypt);
761 180 : return ret;
762 : }
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