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Commit | Line | Data |
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0f950df0 TP |
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" | |
c596f3f0 | 12 | #include "utils/eloop.h" |
0f950df0 TP |
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 "wpa_supplicant_i.h" | |
22 | #include "driver_i.h" | |
23 | #include "wpas_glue.h" | |
24 | #include "mesh_mpm.h" | |
25 | #include "mesh_rsn.h" | |
26 | ||
c596f3f0 CYY |
27 | #define MESH_AUTH_TIMEOUT 10 |
28 | #define MESH_AUTH_RETRY 3 | |
29 | ||
30 | void mesh_auth_timer(void *eloop_ctx, void *user_data) | |
31 | { | |
32 | struct wpa_supplicant *wpa_s = eloop_ctx; | |
33 | struct sta_info *sta = user_data; | |
34 | ||
35 | if (sta->sae->state != SAE_ACCEPTED) { | |
36 | wpa_printf(MSG_DEBUG, "AUTH: Re-authenticate with " MACSTR | |
37 | " (attempt %d) ", | |
38 | MAC2STR(sta->addr), sta->sae_auth_retry); | |
39 | if (sta->sae_auth_retry < MESH_AUTH_RETRY) { | |
40 | mesh_rsn_auth_sae_sta(wpa_s, sta); | |
41 | } else { | |
42 | /* block the STA if exceeded the number of attempts */ | |
43 | sta->plink_state = PLINK_BLOCKED; | |
44 | sta->sae->state = SAE_NOTHING; | |
45 | } | |
46 | sta->sae_auth_retry++; | |
47 | } | |
48 | } | |
49 | ||
0f950df0 TP |
50 | |
51 | static void auth_logger(void *ctx, const u8 *addr, logger_level level, | |
52 | const char *txt) | |
53 | { | |
54 | if (addr) | |
55 | wpa_printf(MSG_DEBUG, "AUTH: " MACSTR " - %s", | |
56 | MAC2STR(addr), txt); | |
57 | else | |
58 | wpa_printf(MSG_DEBUG, "AUTH: %s", txt); | |
59 | } | |
60 | ||
61 | ||
62 | static const u8 *auth_get_psk(void *ctx, const u8 *addr, | |
63 | const u8 *p2p_dev_addr, const u8 *prev_psk) | |
64 | { | |
65 | struct mesh_rsn *mesh_rsn = ctx; | |
66 | struct hostapd_data *hapd = mesh_rsn->wpa_s->ifmsh->bss[0]; | |
67 | struct sta_info *sta = ap_get_sta(hapd, addr); | |
68 | ||
69 | wpa_printf(MSG_DEBUG, "AUTH: %s (addr=" MACSTR " prev_psk=%p)", | |
70 | __func__, MAC2STR(addr), prev_psk); | |
71 | ||
72 | if (sta && sta->auth_alg == WLAN_AUTH_SAE) { | |
73 | if (!sta->sae || prev_psk) | |
74 | return NULL; | |
75 | return sta->sae->pmk; | |
76 | } | |
77 | ||
78 | return NULL; | |
79 | } | |
80 | ||
81 | ||
82 | static int auth_set_key(void *ctx, int vlan_id, enum wpa_alg alg, | |
83 | const u8 *addr, int idx, u8 *key, size_t key_len) | |
84 | { | |
85 | struct mesh_rsn *mesh_rsn = ctx; | |
86 | u8 seq[6]; | |
87 | ||
88 | os_memset(seq, 0, sizeof(seq)); | |
89 | ||
90 | if (addr) { | |
91 | wpa_printf(MSG_DEBUG, "AUTH: %s(alg=%d addr=" MACSTR | |
92 | " key_idx=%d)", | |
93 | __func__, alg, MAC2STR(addr), idx); | |
94 | } else { | |
95 | wpa_printf(MSG_DEBUG, "AUTH: %s(alg=%d key_idx=%d)", | |
96 | __func__, alg, idx); | |
97 | } | |
98 | wpa_hexdump_key(MSG_DEBUG, "AUTH: set_key - key", key, key_len); | |
99 | ||
100 | return wpa_drv_set_key(mesh_rsn->wpa_s, alg, addr, idx, | |
101 | 1, seq, 6, key, key_len); | |
102 | } | |
103 | ||
104 | ||
105 | static int auth_start_ampe(void *ctx, const u8 *addr) | |
106 | { | |
107 | struct mesh_rsn *mesh_rsn = ctx; | |
c596f3f0 CYY |
108 | struct hostapd_data *hapd; |
109 | struct sta_info *sta; | |
0f950df0 TP |
110 | |
111 | if (mesh_rsn->wpa_s->current_ssid->mode != WPAS_MODE_MESH) | |
112 | return -1; | |
113 | ||
c596f3f0 CYY |
114 | hapd = mesh_rsn->wpa_s->ifmsh->bss[0]; |
115 | sta = ap_get_sta(hapd, addr); | |
116 | if (sta) | |
117 | eloop_cancel_timeout(mesh_auth_timer, mesh_rsn->wpa_s, sta); | |
118 | ||
0f950df0 TP |
119 | mesh_mpm_auth_peer(mesh_rsn->wpa_s, addr); |
120 | return 0; | |
121 | } | |
122 | ||
123 | ||
124 | static int __mesh_rsn_auth_init(struct mesh_rsn *rsn, const u8 *addr) | |
125 | { | |
126 | struct wpa_auth_config conf; | |
127 | struct wpa_auth_callbacks cb; | |
128 | u8 seq[6] = {}; | |
129 | ||
130 | wpa_printf(MSG_DEBUG, "AUTH: Initializing group state machine"); | |
131 | ||
132 | os_memset(&conf, 0, sizeof(conf)); | |
133 | conf.wpa = 2; | |
134 | conf.wpa_key_mgmt = WPA_KEY_MGMT_SAE; | |
135 | conf.wpa_pairwise = WPA_CIPHER_CCMP; | |
136 | conf.rsn_pairwise = WPA_CIPHER_CCMP; | |
137 | conf.wpa_group = WPA_CIPHER_CCMP; | |
138 | conf.eapol_version = 0; | |
139 | conf.wpa_group_rekey = -1; | |
140 | ||
141 | os_memset(&cb, 0, sizeof(cb)); | |
142 | cb.ctx = rsn; | |
143 | cb.logger = auth_logger; | |
144 | cb.get_psk = auth_get_psk; | |
145 | cb.set_key = auth_set_key; | |
146 | cb.start_ampe = auth_start_ampe; | |
147 | ||
148 | rsn->auth = wpa_init(addr, &conf, &cb); | |
149 | if (rsn->auth == NULL) { | |
150 | wpa_printf(MSG_DEBUG, "AUTH: wpa_init() failed"); | |
151 | return -1; | |
152 | } | |
153 | ||
154 | /* TODO: support rekeying */ | |
155 | if (random_get_bytes(rsn->mgtk, 16) < 0) { | |
156 | wpa_deinit(rsn->auth); | |
157 | return -1; | |
158 | } | |
159 | ||
160 | /* group mgmt */ | |
161 | wpa_drv_set_key(rsn->wpa_s, WPA_ALG_IGTK, NULL, 4, 1, | |
162 | seq, sizeof(seq), rsn->mgtk, sizeof(rsn->mgtk)); | |
163 | ||
164 | /* group privacy / data frames */ | |
165 | wpa_drv_set_key(rsn->wpa_s, WPA_ALG_CCMP, NULL, 1, 1, | |
166 | seq, sizeof(seq), rsn->mgtk, sizeof(rsn->mgtk)); | |
167 | ||
168 | return 0; | |
169 | } | |
170 | ||
171 | ||
172 | static void mesh_rsn_deinit(struct mesh_rsn *rsn) | |
173 | { | |
174 | os_memset(rsn->mgtk, 0, sizeof(rsn->mgtk)); | |
175 | wpa_deinit(rsn->auth); | |
176 | } | |
177 | ||
178 | ||
179 | struct mesh_rsn *mesh_rsn_auth_init(struct wpa_supplicant *wpa_s, | |
180 | struct mesh_conf *conf) | |
181 | { | |
182 | struct mesh_rsn *mesh_rsn; | |
183 | struct hostapd_data *bss = wpa_s->ifmsh->bss[0]; | |
184 | const u8 *ie; | |
185 | size_t ie_len; | |
186 | ||
187 | mesh_rsn = os_zalloc(sizeof(*mesh_rsn)); | |
188 | if (mesh_rsn == NULL) | |
189 | return NULL; | |
190 | mesh_rsn->wpa_s = wpa_s; | |
191 | ||
192 | if (__mesh_rsn_auth_init(mesh_rsn, wpa_s->own_addr) < 0) { | |
193 | mesh_rsn_deinit(mesh_rsn); | |
194 | return NULL; | |
195 | } | |
196 | ||
197 | bss->wpa_auth = mesh_rsn->auth; | |
198 | ||
199 | ie = wpa_auth_get_wpa_ie(mesh_rsn->auth, &ie_len); | |
200 | conf->ies = (u8 *) ie; | |
201 | conf->ie_len = ie_len; | |
202 | ||
203 | wpa_supplicant_rsn_supp_set_config(wpa_s, wpa_s->current_ssid); | |
204 | ||
205 | return mesh_rsn; | |
206 | } | |
207 | ||
208 | ||
209 | static int index_within_array(const int *array, int idx) | |
210 | { | |
211 | int i; | |
212 | ||
213 | for (i = 0; i < idx; i++) { | |
214 | if (array[i] == -1) | |
215 | return 0; | |
216 | } | |
217 | ||
218 | return 1; | |
219 | } | |
220 | ||
221 | ||
222 | static int mesh_rsn_sae_group(struct wpa_supplicant *wpa_s, | |
223 | struct sae_data *sae) | |
224 | { | |
225 | int *groups = wpa_s->ifmsh->bss[0]->conf->sae_groups; | |
226 | ||
227 | /* Configuration may have changed, so validate current index */ | |
228 | if (!index_within_array(groups, wpa_s->mesh_rsn->sae_group_index)) | |
229 | return -1; | |
230 | ||
231 | for (;;) { | |
232 | int group = groups[wpa_s->mesh_rsn->sae_group_index]; | |
233 | ||
234 | if (group <= 0) | |
235 | break; | |
236 | if (sae_set_group(sae, group) == 0) { | |
237 | wpa_dbg(wpa_s, MSG_DEBUG, "SME: Selected SAE group %d", | |
238 | sae->group); | |
239 | return 0; | |
240 | } | |
241 | wpa_s->mesh_rsn->sae_group_index++; | |
242 | } | |
243 | ||
244 | return -1; | |
245 | } | |
246 | ||
247 | ||
248 | struct wpabuf * | |
249 | mesh_rsn_build_sae_commit(struct wpa_supplicant *wpa_s, | |
250 | struct wpa_ssid *ssid, struct sta_info *sta) | |
251 | { | |
252 | struct wpabuf *buf; | |
253 | int len; | |
254 | ||
255 | if (ssid->passphrase == NULL) { | |
256 | wpa_msg(wpa_s, MSG_DEBUG, "SAE: No password available"); | |
257 | return NULL; | |
258 | } | |
259 | ||
260 | if (mesh_rsn_sae_group(wpa_s, sta->sae) < 0) { | |
261 | wpa_msg(wpa_s, MSG_DEBUG, "SAE: Failed to select group"); | |
262 | return NULL; | |
263 | } | |
264 | ||
265 | if (sae_prepare_commit(wpa_s->own_addr, sta->addr, | |
266 | (u8 *) ssid->passphrase, | |
267 | os_strlen(ssid->passphrase), sta->sae) < 0) { | |
268 | wpa_msg(wpa_s, MSG_DEBUG, "SAE: Could not pick PWE"); | |
269 | return NULL; | |
270 | } | |
271 | ||
272 | len = wpa_s->mesh_rsn->sae_token ? | |
273 | wpabuf_len(wpa_s->mesh_rsn->sae_token) : 0; | |
274 | buf = wpabuf_alloc(4 + SAE_COMMIT_MAX_LEN + len); | |
275 | if (buf == NULL) | |
276 | return NULL; | |
277 | ||
278 | sae_write_commit(sta->sae, buf, wpa_s->mesh_rsn->sae_token); | |
279 | ||
280 | return buf; | |
281 | } | |
282 | ||
283 | ||
284 | static void mesh_rsn_send_auth(struct wpa_supplicant *wpa_s, | |
285 | const u8 *dst, const u8 *src, | |
286 | u16 auth_transaction, u16 resp, | |
287 | struct wpabuf *data) | |
288 | { | |
289 | struct ieee80211_mgmt *auth; | |
290 | u8 *buf; | |
291 | size_t len, ielen = 0; | |
292 | ||
293 | if (data) | |
294 | ielen = wpabuf_len(data); | |
295 | len = IEEE80211_HDRLEN + sizeof(auth->u.auth) + ielen; | |
296 | buf = os_zalloc(len); | |
297 | if (buf == NULL) | |
298 | return; | |
299 | ||
300 | auth = (struct ieee80211_mgmt *) buf; | |
301 | auth->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT, | |
302 | WLAN_FC_STYPE_AUTH); | |
303 | os_memcpy(auth->da, dst, ETH_ALEN); | |
304 | os_memcpy(auth->sa, src, ETH_ALEN); | |
305 | os_memcpy(auth->bssid, src, ETH_ALEN); | |
306 | ||
307 | auth->u.auth.auth_alg = host_to_le16(WLAN_AUTH_SAE); | |
308 | auth->u.auth.auth_transaction = host_to_le16(auth_transaction); | |
309 | auth->u.auth.status_code = host_to_le16(resp); | |
310 | ||
311 | if (data) | |
312 | os_memcpy(auth->u.auth.variable, wpabuf_head(data), ielen); | |
313 | ||
314 | wpa_msg(wpa_s, MSG_DEBUG, "authentication frame: STA=" MACSTR | |
315 | " auth_transaction=%d resp=%d (IE len=%lu)", | |
316 | MAC2STR(dst), auth_transaction, resp, (unsigned long) ielen); | |
317 | if (wpa_drv_send_mlme(wpa_s, buf, len, 0) < 0) | |
318 | perror("send_auth_reply: send"); | |
319 | ||
320 | os_free(buf); | |
321 | } | |
322 | ||
323 | ||
324 | /* initiate new SAE authentication with sta */ | |
325 | int mesh_rsn_auth_sae_sta(struct wpa_supplicant *wpa_s, | |
326 | struct sta_info *sta) | |
327 | { | |
328 | struct wpa_ssid *ssid = wpa_s->current_ssid; | |
329 | struct wpabuf *buf; | |
c596f3f0 | 330 | unsigned int rnd; |
0f950df0 | 331 | |
608b0ff5 JM |
332 | if (!ssid) { |
333 | wpa_msg(wpa_s, MSG_DEBUG, | |
334 | "AUTH: No current_ssid known to initiate new SAE"); | |
335 | return -1; | |
336 | } | |
337 | ||
0f950df0 TP |
338 | if (!sta->sae) { |
339 | sta->sae = os_zalloc(sizeof(*sta->sae)); | |
340 | if (sta->sae == NULL) | |
341 | return -1; | |
342 | } | |
343 | ||
344 | buf = mesh_rsn_build_sae_commit(wpa_s, ssid, sta); | |
345 | if (!buf) | |
346 | return -1; | |
347 | ||
348 | wpa_msg(wpa_s, MSG_DEBUG, | |
349 | "AUTH: started authentication with SAE peer: " MACSTR, | |
350 | MAC2STR(sta->addr)); | |
351 | ||
352 | sta->sae->state = SAE_COMMITTED; | |
353 | wpa_supplicant_set_state(wpa_s, WPA_AUTHENTICATING); | |
354 | ||
355 | mesh_rsn_send_auth(wpa_s, sta->addr, wpa_s->own_addr, | |
356 | 1, WLAN_STATUS_SUCCESS, buf); | |
357 | ||
c596f3f0 CYY |
358 | rnd = rand() % MESH_AUTH_TIMEOUT; |
359 | eloop_register_timeout(MESH_AUTH_TIMEOUT + rnd, 0, mesh_auth_timer, | |
360 | wpa_s, sta); | |
0f950df0 TP |
361 | wpabuf_free(buf); |
362 | ||
363 | return 0; | |
364 | } | |
365 | ||
366 | ||
367 | void mesh_rsn_get_pmkid(struct mesh_rsn *rsn, struct sta_info *sta, u8 *pmkid) | |
368 | { | |
369 | /* don't expect wpa auth to cache the pmkid for now */ | |
370 | rsn_pmkid(sta->sae->pmk, PMK_LEN, rsn->wpa_s->own_addr, | |
371 | sta->addr, pmkid, | |
372 | wpa_key_mgmt_sha256(wpa_auth_sta_key_mgmt(sta->wpa_sm))); | |
373 | } | |
374 | ||
375 | ||
376 | static void | |
377 | mesh_rsn_derive_aek(struct mesh_rsn *rsn, struct sta_info *sta) | |
378 | { | |
379 | u8 *myaddr = rsn->wpa_s->own_addr; | |
380 | u8 *peer = sta->addr; | |
381 | u8 *addr1 = peer, *addr2 = myaddr; | |
382 | u8 context[AES_BLOCK_SIZE]; | |
383 | ||
384 | /* SAE */ | |
385 | RSN_SELECTOR_PUT(context, wpa_cipher_to_suite(0, WPA_CIPHER_GCMP)); | |
386 | ||
387 | if (os_memcmp(myaddr, peer, ETH_ALEN) < 0) { | |
388 | addr1 = myaddr; | |
389 | addr2 = peer; | |
390 | } | |
391 | os_memcpy(context + 4, addr1, ETH_ALEN); | |
392 | os_memcpy(context + 10, addr2, ETH_ALEN); | |
393 | ||
394 | sha256_prf(sta->sae->pmk, sizeof(sta->sae->pmk), "AEK Derivation", | |
395 | context, sizeof(context), sta->aek, sizeof(sta->aek)); | |
396 | } | |
397 | ||
398 | ||
399 | /* derive mesh temporal key from pmk */ | |
400 | int mesh_rsn_derive_mtk(struct wpa_supplicant *wpa_s, struct sta_info *sta) | |
401 | { | |
402 | u8 *ptr; | |
403 | u8 *min, *max; | |
404 | u16 min_lid, max_lid; | |
405 | size_t nonce_len = sizeof(sta->my_nonce); | |
406 | size_t lid_len = sizeof(sta->my_lid); | |
407 | u8 *myaddr = wpa_s->own_addr; | |
408 | u8 *peer = sta->addr; | |
409 | /* 2 nonces, 2 linkids, akm suite, 2 mac addrs */ | |
410 | u8 context[64 + 4 + 4 + 12]; | |
411 | ||
412 | ptr = context; | |
413 | if (os_memcmp(sta->my_nonce, sta->peer_nonce, nonce_len) < 0) { | |
414 | min = sta->my_nonce; | |
415 | max = sta->peer_nonce; | |
416 | } else { | |
417 | min = sta->peer_nonce; | |
418 | max = sta->my_nonce; | |
419 | } | |
420 | os_memcpy(ptr, min, nonce_len); | |
421 | os_memcpy(ptr + nonce_len, max, nonce_len); | |
422 | ptr += 2 * nonce_len; | |
423 | ||
424 | if (sta->my_lid < sta->peer_lid) { | |
425 | min_lid = host_to_le16(sta->my_lid); | |
426 | max_lid = host_to_le16(sta->peer_lid); | |
427 | } else { | |
428 | min_lid = host_to_le16(sta->peer_lid); | |
429 | max_lid = host_to_le16(sta->my_lid); | |
430 | } | |
431 | os_memcpy(ptr, &min_lid, lid_len); | |
432 | os_memcpy(ptr + lid_len, &max_lid, lid_len); | |
433 | ptr += 2 * lid_len; | |
434 | ||
435 | /* SAE */ | |
436 | RSN_SELECTOR_PUT(ptr, wpa_cipher_to_suite(0, WPA_CIPHER_GCMP)); | |
437 | ptr += 4; | |
438 | ||
439 | if (os_memcmp(myaddr, peer, ETH_ALEN) < 0) { | |
440 | min = myaddr; | |
441 | max = peer; | |
442 | } else { | |
443 | min = peer; | |
444 | max = myaddr; | |
445 | } | |
446 | os_memcpy(ptr, min, ETH_ALEN); | |
447 | os_memcpy(ptr + ETH_ALEN, max, ETH_ALEN); | |
448 | ||
449 | sha256_prf(sta->sae->pmk, sizeof(sta->sae->pmk), | |
450 | "Temporal Key Derivation", context, sizeof(context), | |
451 | sta->mtk, sizeof(sta->mtk)); | |
452 | return 0; | |
453 | } | |
454 | ||
455 | ||
456 | void mesh_rsn_init_ampe_sta(struct wpa_supplicant *wpa_s, struct sta_info *sta) | |
457 | { | |
458 | if (random_get_bytes(sta->my_nonce, 32) < 0) { | |
459 | wpa_printf(MSG_INFO, "mesh: Failed to derive random nonce"); | |
460 | /* TODO: How to handle this more cleanly? */ | |
461 | } | |
462 | os_memset(sta->peer_nonce, 0, 32); | |
463 | mesh_rsn_derive_aek(wpa_s->mesh_rsn, sta); | |
464 | } | |
465 | ||
466 | ||
467 | /* insert AMPE and encrypted MIC at @ie. | |
468 | * @mesh_rsn: mesh RSN context | |
469 | * @sta: STA we're sending to | |
470 | * @cat: pointer to category code in frame header. | |
471 | * @buf: wpabuf to add encrypted AMPE and MIC to. | |
472 | * */ | |
473 | int mesh_rsn_protect_frame(struct mesh_rsn *rsn, struct sta_info *sta, | |
474 | const u8 *cat, struct wpabuf *buf) | |
475 | { | |
476 | struct ieee80211_ampe_ie *ampe; | |
477 | u8 const *ie = wpabuf_head_u8(buf) + wpabuf_len(buf); | |
478 | u8 *ampe_ie = NULL, *mic_ie = NULL, *mic_payload; | |
479 | const u8 *aad[] = { rsn->wpa_s->own_addr, sta->addr, cat }; | |
480 | const size_t aad_len[] = { ETH_ALEN, ETH_ALEN, ie - cat }; | |
481 | int ret = 0; | |
482 | ||
483 | if (AES_BLOCK_SIZE + 2 + sizeof(*ampe) + 2 > wpabuf_tailroom(buf)) { | |
484 | wpa_printf(MSG_ERROR, "protect frame: buffer too small"); | |
485 | return -EINVAL; | |
486 | } | |
487 | ||
488 | ampe_ie = os_zalloc(2 + sizeof(*ampe)); | |
489 | if (!ampe_ie) { | |
490 | wpa_printf(MSG_ERROR, "protect frame: out of memory"); | |
491 | return -ENOMEM; | |
492 | } | |
493 | ||
494 | mic_ie = os_zalloc(2 + AES_BLOCK_SIZE); | |
495 | if (!mic_ie) { | |
496 | wpa_printf(MSG_ERROR, "protect frame: out of memory"); | |
497 | ret = -ENOMEM; | |
498 | goto free; | |
499 | } | |
500 | ||
501 | /* IE: AMPE */ | |
502 | ampe_ie[0] = WLAN_EID_AMPE; | |
503 | ampe_ie[1] = sizeof(*ampe); | |
504 | ampe = (struct ieee80211_ampe_ie *) (ampe_ie + 2); | |
505 | ||
506 | RSN_SELECTOR_PUT(ampe->selected_pairwise_suite, | |
507 | wpa_cipher_to_suite(WPA_PROTO_RSN, WPA_CIPHER_CCMP)); | |
508 | os_memcpy(ampe->local_nonce, sta->my_nonce, 32); | |
509 | os_memcpy(ampe->peer_nonce, sta->peer_nonce, 32); | |
510 | /* incomplete: see 13.5.4 */ | |
511 | /* TODO: static mgtk for now since we don't support rekeying! */ | |
512 | os_memcpy(ampe->mgtk, rsn->mgtk, 16); | |
513 | /* TODO: Populate Key RSC */ | |
514 | /* expire in 13 decades or so */ | |
515 | os_memset(ampe->key_expiration, 0xff, 4); | |
516 | ||
517 | /* IE: MIC */ | |
518 | mic_ie[0] = WLAN_EID_MIC; | |
519 | mic_ie[1] = AES_BLOCK_SIZE; | |
520 | wpabuf_put_data(buf, mic_ie, 2); | |
521 | /* MIC field is output ciphertext */ | |
522 | ||
523 | /* encrypt after MIC */ | |
524 | mic_payload = (u8 *) wpabuf_put(buf, 2 + sizeof(*ampe) + | |
525 | AES_BLOCK_SIZE); | |
526 | ||
527 | if (aes_siv_encrypt(sta->aek, ampe_ie, 2 + sizeof(*ampe), 3, | |
528 | aad, aad_len, mic_payload)) { | |
529 | wpa_printf(MSG_ERROR, "protect frame: failed to encrypt"); | |
530 | ret = -ENOMEM; | |
531 | goto free; | |
532 | } | |
533 | ||
534 | free: | |
535 | os_free(ampe_ie); | |
536 | os_free(mic_ie); | |
537 | ||
538 | return ret; | |
539 | } | |
540 | ||
541 | ||
542 | int mesh_rsn_process_ampe(struct wpa_supplicant *wpa_s, struct sta_info *sta, | |
543 | struct ieee802_11_elems *elems, const u8 *cat, | |
544 | const u8 *start, size_t elems_len) | |
545 | { | |
546 | int ret = 0; | |
547 | struct ieee80211_ampe_ie *ampe; | |
548 | u8 null_nonce[32] = {}; | |
549 | u8 ampe_eid; | |
550 | u8 ampe_ie_len; | |
551 | u8 *ampe_buf, *crypt = NULL; | |
552 | size_t crypt_len; | |
553 | const u8 *aad[] = { sta->addr, wpa_s->own_addr, cat }; | |
554 | const size_t aad_len[] = { ETH_ALEN, ETH_ALEN, | |
555 | (elems->mic - 2) - cat }; | |
556 | ||
557 | if (!elems->mic || elems->mic_len < AES_BLOCK_SIZE) { | |
558 | wpa_msg(wpa_s, MSG_DEBUG, "Mesh RSN: missing mic ie"); | |
559 | return -1; | |
560 | } | |
561 | ||
562 | ampe_buf = (u8 *) elems->mic + elems->mic_len; | |
563 | if ((int) elems_len < ampe_buf - start) | |
564 | return -1; | |
565 | ||
566 | crypt_len = elems_len - (elems->mic - start); | |
567 | if (crypt_len < 2) { | |
568 | wpa_msg(wpa_s, MSG_DEBUG, "Mesh RSN: missing ampe ie"); | |
569 | return -1; | |
570 | } | |
571 | ||
572 | /* crypt is modified by siv_decrypt */ | |
573 | crypt = os_zalloc(crypt_len); | |
574 | if (!crypt) { | |
575 | wpa_printf(MSG_ERROR, "Mesh RSN: out of memory"); | |
576 | ret = -ENOMEM; | |
577 | goto free; | |
578 | } | |
579 | ||
580 | os_memcpy(crypt, elems->mic, crypt_len); | |
581 | ||
582 | if (aes_siv_decrypt(sta->aek, crypt, crypt_len, 3, | |
583 | aad, aad_len, ampe_buf)) { | |
584 | wpa_printf(MSG_ERROR, "Mesh RSN: frame verification failed!"); | |
585 | ret = -1; | |
586 | goto free; | |
587 | } | |
588 | ||
589 | ampe_eid = *ampe_buf++; | |
590 | ampe_ie_len = *ampe_buf++; | |
591 | ||
592 | if (ampe_eid != WLAN_EID_AMPE || | |
593 | ampe_ie_len < sizeof(struct ieee80211_ampe_ie)) { | |
594 | wpa_msg(wpa_s, MSG_DEBUG, "Mesh RSN: invalid ampe ie"); | |
595 | ret = -1; | |
596 | goto free; | |
597 | } | |
598 | ||
599 | ampe = (struct ieee80211_ampe_ie *) ampe_buf; | |
600 | if (os_memcmp(ampe->peer_nonce, null_nonce, 32) != 0 && | |
601 | os_memcmp(ampe->peer_nonce, sta->my_nonce, 32) != 0) { | |
602 | wpa_msg(wpa_s, MSG_DEBUG, "Mesh RSN: invalid peer nonce"); | |
603 | ret = -1; | |
604 | goto free; | |
605 | } | |
606 | os_memcpy(sta->peer_nonce, ampe->local_nonce, | |
607 | sizeof(ampe->local_nonce)); | |
608 | os_memcpy(sta->mgtk, ampe->mgtk, sizeof(ampe->mgtk)); | |
609 | ||
610 | /* todo parse mgtk expiration */ | |
611 | free: | |
612 | os_free(crypt); | |
613 | return ret; | |
614 | } |