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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" | |
a206e2a1 | 21 | #include "ap/ieee802_11.h" |
0f950df0 TP |
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 | ||
c596f3f0 CYY |
28 | #define MESH_AUTH_TIMEOUT 10 |
29 | #define MESH_AUTH_RETRY 3 | |
30 | ||
31 | void mesh_auth_timer(void *eloop_ctx, void *user_data) | |
32 | { | |
33 | struct wpa_supplicant *wpa_s = eloop_ctx; | |
34 | struct sta_info *sta = user_data; | |
d774c46a | 35 | struct hostapd_data *hapd; |
c596f3f0 CYY |
36 | |
37 | if (sta->sae->state != SAE_ACCEPTED) { | |
38 | wpa_printf(MSG_DEBUG, "AUTH: Re-authenticate with " MACSTR | |
39 | " (attempt %d) ", | |
40 | MAC2STR(sta->addr), sta->sae_auth_retry); | |
dd2cbafc MH |
41 | wpa_msg(wpa_s, MSG_INFO, MESH_SAE_AUTH_FAILURE "addr=" MACSTR, |
42 | MAC2STR(sta->addr)); | |
c596f3f0 CYY |
43 | if (sta->sae_auth_retry < MESH_AUTH_RETRY) { |
44 | mesh_rsn_auth_sae_sta(wpa_s, sta); | |
45 | } else { | |
d774c46a MH |
46 | hapd = wpa_s->ifmsh->bss[0]; |
47 | ||
bf51f4f8 | 48 | if (sta->sae_auth_retry > MESH_AUTH_RETRY) { |
d774c46a | 49 | ap_free_sta(hapd, sta); |
bf51f4f8 MH |
50 | return; |
51 | } | |
52 | ||
c596f3f0 | 53 | /* block the STA if exceeded the number of attempts */ |
871ff0b7 | 54 | wpa_mesh_set_plink_state(wpa_s, sta, PLINK_BLOCKED); |
c596f3f0 | 55 | sta->sae->state = SAE_NOTHING; |
79ddb206 | 56 | wpa_msg(wpa_s, MSG_INFO, MESH_SAE_AUTH_BLOCKED "addr=" |
bf51f4f8 MH |
57 | MACSTR " duration=%d", |
58 | MAC2STR(sta->addr), | |
d774c46a | 59 | hapd->conf->ap_max_inactivity); |
c596f3f0 CYY |
60 | } |
61 | sta->sae_auth_retry++; | |
62 | } | |
63 | } | |
64 | ||
0f950df0 TP |
65 | |
66 | static void auth_logger(void *ctx, const u8 *addr, logger_level level, | |
67 | const char *txt) | |
68 | { | |
69 | if (addr) | |
70 | wpa_printf(MSG_DEBUG, "AUTH: " MACSTR " - %s", | |
71 | MAC2STR(addr), txt); | |
72 | else | |
73 | wpa_printf(MSG_DEBUG, "AUTH: %s", txt); | |
74 | } | |
75 | ||
76 | ||
77 | static const u8 *auth_get_psk(void *ctx, const u8 *addr, | |
7a12edd1 | 78 | const u8 *p2p_dev_addr, const u8 *prev_psk, |
dbfa691d | 79 | size_t *psk_len, int *vlan_id) |
0f950df0 TP |
80 | { |
81 | struct mesh_rsn *mesh_rsn = ctx; | |
82 | struct hostapd_data *hapd = mesh_rsn->wpa_s->ifmsh->bss[0]; | |
83 | struct sta_info *sta = ap_get_sta(hapd, addr); | |
84 | ||
7a12edd1 JM |
85 | if (psk_len) |
86 | *psk_len = PMK_LEN; | |
dbfa691d JM |
87 | if (vlan_id) |
88 | *vlan_id = 0; | |
0f950df0 TP |
89 | wpa_printf(MSG_DEBUG, "AUTH: %s (addr=" MACSTR " prev_psk=%p)", |
90 | __func__, MAC2STR(addr), prev_psk); | |
91 | ||
92 | if (sta && sta->auth_alg == WLAN_AUTH_SAE) { | |
93 | if (!sta->sae || prev_psk) | |
94 | return NULL; | |
95 | return sta->sae->pmk; | |
96 | } | |
97 | ||
98 | return NULL; | |
99 | } | |
100 | ||
101 | ||
102 | static int auth_set_key(void *ctx, int vlan_id, enum wpa_alg alg, | |
a919a260 AW |
103 | const u8 *addr, int idx, u8 *key, size_t key_len, |
104 | enum key_flag key_flag) | |
0f950df0 TP |
105 | { |
106 | struct mesh_rsn *mesh_rsn = ctx; | |
107 | u8 seq[6]; | |
108 | ||
109 | os_memset(seq, 0, sizeof(seq)); | |
110 | ||
111 | if (addr) { | |
112 | wpa_printf(MSG_DEBUG, "AUTH: %s(alg=%d addr=" MACSTR | |
113 | " key_idx=%d)", | |
114 | __func__, alg, MAC2STR(addr), idx); | |
115 | } else { | |
116 | wpa_printf(MSG_DEBUG, "AUTH: %s(alg=%d key_idx=%d)", | |
117 | __func__, alg, idx); | |
118 | } | |
119 | wpa_hexdump_key(MSG_DEBUG, "AUTH: set_key - key", key, key_len); | |
120 | ||
121 | return wpa_drv_set_key(mesh_rsn->wpa_s, alg, addr, idx, | |
a919a260 | 122 | 1, seq, 6, key, key_len, key_flag); |
0f950df0 TP |
123 | } |
124 | ||
125 | ||
126 | static int auth_start_ampe(void *ctx, const u8 *addr) | |
127 | { | |
128 | struct mesh_rsn *mesh_rsn = ctx; | |
c596f3f0 CYY |
129 | struct hostapd_data *hapd; |
130 | struct sta_info *sta; | |
0f950df0 TP |
131 | |
132 | if (mesh_rsn->wpa_s->current_ssid->mode != WPAS_MODE_MESH) | |
133 | return -1; | |
134 | ||
c596f3f0 CYY |
135 | hapd = mesh_rsn->wpa_s->ifmsh->bss[0]; |
136 | sta = ap_get_sta(hapd, addr); | |
137 | if (sta) | |
138 | eloop_cancel_timeout(mesh_auth_timer, mesh_rsn->wpa_s, sta); | |
139 | ||
0f950df0 TP |
140 | mesh_mpm_auth_peer(mesh_rsn->wpa_s, addr); |
141 | return 0; | |
142 | } | |
143 | ||
144 | ||
18aca1a0 | 145 | static int __mesh_rsn_auth_init(struct mesh_rsn *rsn, const u8 *addr, |
716ed96e | 146 | enum mfp_options ieee80211w, int ocv) |
0f950df0 TP |
147 | { |
148 | struct wpa_auth_config conf; | |
cef8fac0 JB |
149 | static const struct wpa_auth_callbacks cb = { |
150 | .logger = auth_logger, | |
151 | .get_psk = auth_get_psk, | |
152 | .set_key = auth_set_key, | |
153 | .start_ampe = auth_start_ampe, | |
154 | }; | |
0f950df0 TP |
155 | u8 seq[6] = {}; |
156 | ||
157 | wpa_printf(MSG_DEBUG, "AUTH: Initializing group state machine"); | |
158 | ||
159 | os_memset(&conf, 0, sizeof(conf)); | |
3b6deac0 | 160 | conf.wpa = WPA_PROTO_RSN; |
0f950df0 | 161 | conf.wpa_key_mgmt = WPA_KEY_MGMT_SAE; |
3b6deac0 JM |
162 | conf.wpa_pairwise = rsn->pairwise_cipher; |
163 | conf.rsn_pairwise = rsn->pairwise_cipher; | |
164 | conf.wpa_group = rsn->group_cipher; | |
0f950df0 TP |
165 | conf.eapol_version = 0; |
166 | conf.wpa_group_rekey = -1; | |
41f140d3 GK |
167 | conf.wpa_group_update_count = 4; |
168 | conf.wpa_pairwise_update_count = 4; | |
18aca1a0 JM |
169 | conf.ieee80211w = ieee80211w; |
170 | if (ieee80211w != NO_MGMT_FRAME_PROTECTION) | |
3b6deac0 | 171 | conf.group_mgmt_cipher = rsn->mgmt_group_cipher; |
716ed96e MV |
172 | #ifdef CONFIG_OCV |
173 | conf.ocv = ocv; | |
174 | #endif /* CONFIG_OCV */ | |
0f950df0 | 175 | |
cef8fac0 | 176 | rsn->auth = wpa_init(addr, &conf, &cb, rsn); |
0f950df0 TP |
177 | if (rsn->auth == NULL) { |
178 | wpa_printf(MSG_DEBUG, "AUTH: wpa_init() failed"); | |
179 | return -1; | |
180 | } | |
181 | ||
182 | /* TODO: support rekeying */ | |
3b6deac0 | 183 | rsn->mgtk_len = wpa_cipher_key_len(conf.wpa_group); |
696f7923 | 184 | if (random_get_bytes(rsn->mgtk, rsn->mgtk_len) < 0) |
0f950df0 | 185 | return -1; |
f868d560 | 186 | rsn->mgtk_key_id = 1; |
0f950df0 | 187 | |
fccba2c9 | 188 | if (ieee80211w != NO_MGMT_FRAME_PROTECTION) { |
3b6deac0 | 189 | rsn->igtk_len = wpa_cipher_key_len(conf.group_mgmt_cipher); |
f868d560 | 190 | if (random_get_bytes(rsn->igtk, rsn->igtk_len) < 0) |
fccba2c9 | 191 | return -1; |
f868d560 | 192 | rsn->igtk_key_id = 4; |
fccba2c9 JM |
193 | |
194 | /* group mgmt */ | |
195 | wpa_hexdump_key(MSG_DEBUG, "mesh: Own TX IGTK", | |
196 | rsn->igtk, rsn->igtk_len); | |
3b6deac0 JM |
197 | wpa_drv_set_key(rsn->wpa_s, |
198 | wpa_cipher_to_alg(rsn->mgmt_group_cipher), NULL, | |
f868d560 | 199 | rsn->igtk_key_id, 1, |
a919a260 AW |
200 | seq, sizeof(seq), rsn->igtk, rsn->igtk_len, |
201 | KEY_FLAG_GROUP_TX_DEFAULT); | |
fccba2c9 | 202 | } |
0f950df0 TP |
203 | |
204 | /* group privacy / data frames */ | |
696f7923 JM |
205 | wpa_hexdump_key(MSG_DEBUG, "mesh: Own TX MGTK", |
206 | rsn->mgtk, rsn->mgtk_len); | |
3b6deac0 JM |
207 | wpa_drv_set_key(rsn->wpa_s, wpa_cipher_to_alg(rsn->group_cipher), NULL, |
208 | rsn->mgtk_key_id, 1, seq, sizeof(seq), | |
a919a260 | 209 | rsn->mgtk, rsn->mgtk_len, KEY_FLAG_GROUP_TX_DEFAULT); |
0f950df0 TP |
210 | |
211 | return 0; | |
212 | } | |
213 | ||
214 | ||
215 | static void mesh_rsn_deinit(struct mesh_rsn *rsn) | |
216 | { | |
217 | os_memset(rsn->mgtk, 0, sizeof(rsn->mgtk)); | |
696f7923 | 218 | rsn->mgtk_len = 0; |
fccba2c9 JM |
219 | os_memset(rsn->igtk, 0, sizeof(rsn->igtk)); |
220 | rsn->igtk_len = 0; | |
a5d2bf24 MH |
221 | if (rsn->auth) |
222 | wpa_deinit(rsn->auth); | |
0f950df0 TP |
223 | } |
224 | ||
225 | ||
226 | struct mesh_rsn *mesh_rsn_auth_init(struct wpa_supplicant *wpa_s, | |
227 | struct mesh_conf *conf) | |
228 | { | |
229 | struct mesh_rsn *mesh_rsn; | |
230 | struct hostapd_data *bss = wpa_s->ifmsh->bss[0]; | |
231 | const u8 *ie; | |
232 | size_t ie_len; | |
4d77d80e MH |
233 | #ifdef CONFIG_PMKSA_CACHE_EXTERNAL |
234 | struct external_pmksa_cache *entry; | |
235 | #endif /* CONFIG_PMKSA_CACHE_EXTERNAL */ | |
0f950df0 TP |
236 | |
237 | mesh_rsn = os_zalloc(sizeof(*mesh_rsn)); | |
238 | if (mesh_rsn == NULL) | |
239 | return NULL; | |
240 | mesh_rsn->wpa_s = wpa_s; | |
3b6deac0 JM |
241 | mesh_rsn->pairwise_cipher = conf->pairwise_cipher; |
242 | mesh_rsn->group_cipher = conf->group_cipher; | |
243 | mesh_rsn->mgmt_group_cipher = conf->mgmt_group_cipher; | |
0f950df0 | 244 | |
18aca1a0 | 245 | if (__mesh_rsn_auth_init(mesh_rsn, wpa_s->own_addr, |
716ed96e | 246 | conf->ieee80211w, conf->ocv) < 0) { |
0f950df0 | 247 | mesh_rsn_deinit(mesh_rsn); |
449d63d6 | 248 | os_free(mesh_rsn); |
0f950df0 TP |
249 | return NULL; |
250 | } | |
251 | ||
252 | bss->wpa_auth = mesh_rsn->auth; | |
253 | ||
4d77d80e MH |
254 | #ifdef CONFIG_PMKSA_CACHE_EXTERNAL |
255 | while ((entry = dl_list_last(&wpa_s->mesh_external_pmksa_cache, | |
256 | struct external_pmksa_cache, | |
257 | list)) != NULL) { | |
258 | int ret; | |
259 | ||
260 | ret = wpa_auth_pmksa_add_entry(bss->wpa_auth, | |
261 | entry->pmksa_cache); | |
262 | dl_list_del(&entry->list); | |
263 | os_free(entry); | |
264 | ||
265 | if (ret < 0) | |
266 | return NULL; | |
267 | } | |
268 | #endif /* CONFIG_PMKSA_CACHE_EXTERNAL */ | |
269 | ||
0f950df0 | 270 | ie = wpa_auth_get_wpa_ie(mesh_rsn->auth, &ie_len); |
8a51dcbc MH |
271 | conf->rsn_ie = (u8 *) ie; |
272 | conf->rsn_ie_len = ie_len; | |
0f950df0 TP |
273 | |
274 | wpa_supplicant_rsn_supp_set_config(wpa_s, wpa_s->current_ssid); | |
275 | ||
276 | return mesh_rsn; | |
277 | } | |
278 | ||
279 | ||
280 | static int index_within_array(const int *array, int idx) | |
281 | { | |
282 | int i; | |
283 | ||
284 | for (i = 0; i < idx; i++) { | |
285 | if (array[i] == -1) | |
286 | return 0; | |
287 | } | |
288 | ||
289 | return 1; | |
290 | } | |
291 | ||
292 | ||
293 | static int mesh_rsn_sae_group(struct wpa_supplicant *wpa_s, | |
294 | struct sae_data *sae) | |
295 | { | |
296 | int *groups = wpa_s->ifmsh->bss[0]->conf->sae_groups; | |
297 | ||
298 | /* Configuration may have changed, so validate current index */ | |
299 | if (!index_within_array(groups, wpa_s->mesh_rsn->sae_group_index)) | |
300 | return -1; | |
301 | ||
302 | for (;;) { | |
303 | int group = groups[wpa_s->mesh_rsn->sae_group_index]; | |
304 | ||
305 | if (group <= 0) | |
306 | break; | |
307 | if (sae_set_group(sae, group) == 0) { | |
308 | wpa_dbg(wpa_s, MSG_DEBUG, "SME: Selected SAE group %d", | |
309 | sae->group); | |
310 | return 0; | |
311 | } | |
312 | wpa_s->mesh_rsn->sae_group_index++; | |
313 | } | |
314 | ||
315 | return -1; | |
316 | } | |
317 | ||
318 | ||
a206e2a1 BC |
319 | static int mesh_rsn_build_sae_commit(struct wpa_supplicant *wpa_s, |
320 | struct wpa_ssid *ssid, | |
321 | struct sta_info *sta) | |
0f950df0 | 322 | { |
a34ca59e JM |
323 | const char *password; |
324 | ||
325 | password = ssid->sae_password; | |
326 | if (!password) | |
327 | password = ssid->passphrase; | |
328 | if (!password) { | |
0f950df0 | 329 | wpa_msg(wpa_s, MSG_DEBUG, "SAE: No password available"); |
a206e2a1 | 330 | return -1; |
0f950df0 TP |
331 | } |
332 | ||
333 | if (mesh_rsn_sae_group(wpa_s, sta->sae) < 0) { | |
334 | wpa_msg(wpa_s, MSG_DEBUG, "SAE: Failed to select group"); | |
a206e2a1 | 335 | return -1; |
0f950df0 TP |
336 | } |
337 | ||
9be19d0b JM |
338 | if (sta->sae->tmp && !sta->sae->tmp->pw_id && ssid->sae_password_id) { |
339 | sta->sae->tmp->pw_id = os_strdup(ssid->sae_password_id); | |
340 | if (!sta->sae->tmp->pw_id) | |
341 | return -1; | |
342 | } | |
a206e2a1 | 343 | return sae_prepare_commit(wpa_s->own_addr, sta->addr, |
a34ca59e | 344 | (u8 *) password, os_strlen(password), |
9be19d0b | 345 | ssid->sae_password_id, |
a34ca59e | 346 | sta->sae); |
0f950df0 TP |
347 | } |
348 | ||
349 | ||
350 | /* initiate new SAE authentication with sta */ | |
351 | int mesh_rsn_auth_sae_sta(struct wpa_supplicant *wpa_s, | |
352 | struct sta_info *sta) | |
353 | { | |
a206e2a1 | 354 | struct hostapd_data *hapd = wpa_s->ifmsh->bss[0]; |
0f950df0 | 355 | struct wpa_ssid *ssid = wpa_s->current_ssid; |
9f2cf23e | 356 | struct rsn_pmksa_cache_entry *pmksa; |
c596f3f0 | 357 | unsigned int rnd; |
a206e2a1 | 358 | int ret; |
0f950df0 | 359 | |
608b0ff5 JM |
360 | if (!ssid) { |
361 | wpa_msg(wpa_s, MSG_DEBUG, | |
362 | "AUTH: No current_ssid known to initiate new SAE"); | |
363 | return -1; | |
364 | } | |
365 | ||
0f950df0 TP |
366 | if (!sta->sae) { |
367 | sta->sae = os_zalloc(sizeof(*sta->sae)); | |
368 | if (sta->sae == NULL) | |
369 | return -1; | |
370 | } | |
371 | ||
c1bd4bac | 372 | pmksa = wpa_auth_pmksa_get(hapd->wpa_auth, sta->addr, NULL); |
9f2cf23e MH |
373 | if (pmksa) { |
374 | if (!sta->wpa_sm) | |
375 | sta->wpa_sm = wpa_auth_sta_init(hapd->wpa_auth, | |
376 | sta->addr, NULL); | |
377 | if (!sta->wpa_sm) { | |
378 | wpa_printf(MSG_ERROR, | |
379 | "mesh: Failed to initialize RSN state machine"); | |
380 | return -1; | |
381 | } | |
382 | ||
383 | wpa_printf(MSG_DEBUG, | |
384 | "AUTH: Mesh PMKSA cache entry found for " MACSTR | |
385 | " - try to use PMKSA caching instead of new SAE authentication", | |
386 | MAC2STR(sta->addr)); | |
387 | wpa_auth_pmksa_set_to_sm(pmksa, sta->wpa_sm, hapd->wpa_auth, | |
388 | sta->sae->pmkid, sta->sae->pmk); | |
389 | sae_accept_sta(hapd, sta); | |
390 | sta->mesh_sae_pmksa_caching = 1; | |
391 | return 0; | |
392 | } | |
393 | sta->mesh_sae_pmksa_caching = 0; | |
394 | ||
a206e2a1 | 395 | if (mesh_rsn_build_sae_commit(wpa_s, ssid, sta)) |
0f950df0 TP |
396 | return -1; |
397 | ||
398 | wpa_msg(wpa_s, MSG_DEBUG, | |
399 | "AUTH: started authentication with SAE peer: " MACSTR, | |
400 | MAC2STR(sta->addr)); | |
401 | ||
a206e2a1 BC |
402 | ret = auth_sae_init_committed(hapd, sta); |
403 | if (ret) | |
404 | return ret; | |
0f950df0 | 405 | |
bf51f4f8 | 406 | eloop_cancel_timeout(mesh_auth_timer, wpa_s, sta); |
c596f3f0 CYY |
407 | rnd = rand() % MESH_AUTH_TIMEOUT; |
408 | eloop_register_timeout(MESH_AUTH_TIMEOUT + rnd, 0, mesh_auth_timer, | |
409 | wpa_s, sta); | |
0f950df0 TP |
410 | return 0; |
411 | } | |
412 | ||
413 | ||
414 | void mesh_rsn_get_pmkid(struct mesh_rsn *rsn, struct sta_info *sta, u8 *pmkid) | |
415 | { | |
6c33eed3 | 416 | os_memcpy(pmkid, sta->sae->pmkid, SAE_PMKID_LEN); |
0f950df0 TP |
417 | } |
418 | ||
419 | ||
420 | static void | |
421 | mesh_rsn_derive_aek(struct mesh_rsn *rsn, struct sta_info *sta) | |
422 | { | |
423 | u8 *myaddr = rsn->wpa_s->own_addr; | |
424 | u8 *peer = sta->addr; | |
f5ba6923 JM |
425 | u8 *addr1, *addr2; |
426 | u8 context[RSN_SELECTOR_LEN + 2 * ETH_ALEN], *ptr = context; | |
0f950df0 | 427 | |
f5ba6923 JM |
428 | /* |
429 | * AEK = KDF-Hash-256(PMK, "AEK Derivation", Selected AKM Suite || | |
430 | * min(localMAC, peerMAC) || max(localMAC, peerMAC)) | |
431 | */ | |
a59c5e92 | 432 | /* Selected AKM Suite: SAE */ |
f5ba6923 JM |
433 | RSN_SELECTOR_PUT(ptr, RSN_AUTH_KEY_MGMT_SAE); |
434 | ptr += RSN_SELECTOR_LEN; | |
0f950df0 TP |
435 | |
436 | if (os_memcmp(myaddr, peer, ETH_ALEN) < 0) { | |
437 | addr1 = myaddr; | |
438 | addr2 = peer; | |
f5ba6923 JM |
439 | } else { |
440 | addr1 = peer; | |
441 | addr2 = myaddr; | |
0f950df0 | 442 | } |
f5ba6923 JM |
443 | os_memcpy(ptr, addr1, ETH_ALEN); |
444 | ptr += ETH_ALEN; | |
445 | os_memcpy(ptr, addr2, ETH_ALEN); | |
0f950df0 TP |
446 | |
447 | sha256_prf(sta->sae->pmk, sizeof(sta->sae->pmk), "AEK Derivation", | |
448 | context, sizeof(context), sta->aek, sizeof(sta->aek)); | |
449 | } | |
450 | ||
451 | ||
452 | /* derive mesh temporal key from pmk */ | |
453 | int mesh_rsn_derive_mtk(struct wpa_supplicant *wpa_s, struct sta_info *sta) | |
454 | { | |
455 | u8 *ptr; | |
456 | u8 *min, *max; | |
0f950df0 TP |
457 | u8 *myaddr = wpa_s->own_addr; |
458 | u8 *peer = sta->addr; | |
846201df | 459 | u8 context[2 * WPA_NONCE_LEN + 2 * 2 + RSN_SELECTOR_LEN + 2 * ETH_ALEN]; |
0f950df0 | 460 | |
846201df JM |
461 | /* |
462 | * MTK = KDF-Hash-Length(PMK, "Temporal Key Derivation", min(localNonce, | |
463 | * peerNonce) || max(localNonce, peerNonce) || min(localLinkID, | |
464 | * peerLinkID) || max(localLinkID, peerLinkID) || Selected AKM Suite || | |
465 | * min(localMAC, peerMAC) || max(localMAC, peerMAC)) | |
466 | */ | |
0f950df0 | 467 | ptr = context; |
b8b499e4 | 468 | if (os_memcmp(sta->my_nonce, sta->peer_nonce, WPA_NONCE_LEN) < 0) { |
0f950df0 TP |
469 | min = sta->my_nonce; |
470 | max = sta->peer_nonce; | |
471 | } else { | |
472 | min = sta->peer_nonce; | |
473 | max = sta->my_nonce; | |
474 | } | |
b8b499e4 | 475 | os_memcpy(ptr, min, WPA_NONCE_LEN); |
846201df JM |
476 | ptr += WPA_NONCE_LEN; |
477 | os_memcpy(ptr, max, WPA_NONCE_LEN); | |
478 | ptr += WPA_NONCE_LEN; | |
0f950df0 TP |
479 | |
480 | if (sta->my_lid < sta->peer_lid) { | |
846201df JM |
481 | WPA_PUT_LE16(ptr, sta->my_lid); |
482 | ptr += 2; | |
483 | WPA_PUT_LE16(ptr, sta->peer_lid); | |
484 | ptr += 2; | |
0f950df0 | 485 | } else { |
846201df JM |
486 | WPA_PUT_LE16(ptr, sta->peer_lid); |
487 | ptr += 2; | |
488 | WPA_PUT_LE16(ptr, sta->my_lid); | |
489 | ptr += 2; | |
0f950df0 | 490 | } |
0f950df0 | 491 | |
0f76d824 JM |
492 | /* Selected AKM Suite: SAE */ |
493 | RSN_SELECTOR_PUT(ptr, RSN_AUTH_KEY_MGMT_SAE); | |
846201df | 494 | ptr += RSN_SELECTOR_LEN; |
0f950df0 TP |
495 | |
496 | if (os_memcmp(myaddr, peer, ETH_ALEN) < 0) { | |
497 | min = myaddr; | |
498 | max = peer; | |
499 | } else { | |
500 | min = peer; | |
501 | max = myaddr; | |
502 | } | |
503 | os_memcpy(ptr, min, ETH_ALEN); | |
846201df JM |
504 | ptr += ETH_ALEN; |
505 | os_memcpy(ptr, max, ETH_ALEN); | |
0f950df0 | 506 | |
3b6deac0 | 507 | sta->mtk_len = wpa_cipher_key_len(wpa_s->mesh_rsn->pairwise_cipher); |
846201df | 508 | sha256_prf(sta->sae->pmk, SAE_PMK_LEN, |
0f950df0 | 509 | "Temporal Key Derivation", context, sizeof(context), |
b02f4d05 | 510 | sta->mtk, sta->mtk_len); |
0f950df0 TP |
511 | return 0; |
512 | } | |
513 | ||
514 | ||
515 | void mesh_rsn_init_ampe_sta(struct wpa_supplicant *wpa_s, struct sta_info *sta) | |
516 | { | |
b8b499e4 | 517 | if (random_get_bytes(sta->my_nonce, WPA_NONCE_LEN) < 0) { |
0f950df0 TP |
518 | wpa_printf(MSG_INFO, "mesh: Failed to derive random nonce"); |
519 | /* TODO: How to handle this more cleanly? */ | |
520 | } | |
b8b499e4 | 521 | os_memset(sta->peer_nonce, 0, WPA_NONCE_LEN); |
0f950df0 TP |
522 | mesh_rsn_derive_aek(wpa_s->mesh_rsn, sta); |
523 | } | |
524 | ||
525 | ||
526 | /* insert AMPE and encrypted MIC at @ie. | |
527 | * @mesh_rsn: mesh RSN context | |
528 | * @sta: STA we're sending to | |
529 | * @cat: pointer to category code in frame header. | |
530 | * @buf: wpabuf to add encrypted AMPE and MIC to. | |
531 | * */ | |
532 | int mesh_rsn_protect_frame(struct mesh_rsn *rsn, struct sta_info *sta, | |
533 | const u8 *cat, struct wpabuf *buf) | |
534 | { | |
535 | struct ieee80211_ampe_ie *ampe; | |
536 | u8 const *ie = wpabuf_head_u8(buf) + wpabuf_len(buf); | |
f868d560 | 537 | u8 *ampe_ie, *pos, *mic_payload; |
0f950df0 TP |
538 | const u8 *aad[] = { rsn->wpa_s->own_addr, sta->addr, cat }; |
539 | const size_t aad_len[] = { ETH_ALEN, ETH_ALEN, ie - cat }; | |
540 | int ret = 0; | |
f868d560 | 541 | size_t len; |
0f950df0 | 542 | |
ee0ad453 JM |
543 | len = sizeof(*ampe); |
544 | if (cat[1] == PLINK_OPEN) | |
545 | len += rsn->mgtk_len + WPA_KEY_RSC_LEN + 4; | |
ee0ad453 | 546 | if (cat[1] == PLINK_OPEN && rsn->igtk_len) |
f868d560 | 547 | len += 2 + 6 + rsn->igtk_len; |
f868d560 JM |
548 | |
549 | if (2 + AES_BLOCK_SIZE + 2 + len > wpabuf_tailroom(buf)) { | |
0f950df0 TP |
550 | wpa_printf(MSG_ERROR, "protect frame: buffer too small"); |
551 | return -EINVAL; | |
552 | } | |
553 | ||
f868d560 | 554 | ampe_ie = os_zalloc(2 + len); |
0f950df0 TP |
555 | if (!ampe_ie) { |
556 | wpa_printf(MSG_ERROR, "protect frame: out of memory"); | |
557 | return -ENOMEM; | |
558 | } | |
559 | ||
0f950df0 TP |
560 | /* IE: AMPE */ |
561 | ampe_ie[0] = WLAN_EID_AMPE; | |
f868d560 | 562 | ampe_ie[1] = len; |
0f950df0 TP |
563 | ampe = (struct ieee80211_ampe_ie *) (ampe_ie + 2); |
564 | ||
565 | RSN_SELECTOR_PUT(ampe->selected_pairwise_suite, | |
f868d560 | 566 | RSN_CIPHER_SUITE_CCMP); |
b8b499e4 JM |
567 | os_memcpy(ampe->local_nonce, sta->my_nonce, WPA_NONCE_LEN); |
568 | os_memcpy(ampe->peer_nonce, sta->peer_nonce, WPA_NONCE_LEN); | |
f868d560 JM |
569 | |
570 | pos = (u8 *) (ampe + 1); | |
ee0ad453 JM |
571 | if (cat[1] != PLINK_OPEN) |
572 | goto skip_keys; | |
f868d560 JM |
573 | |
574 | /* TODO: Key Replay Counter[8] optionally for | |
575 | * Mesh Group Key Inform/Acknowledge frames */ | |
576 | ||
0f950df0 | 577 | /* TODO: static mgtk for now since we don't support rekeying! */ |
f868d560 JM |
578 | /* |
579 | * GTKdata[variable]: | |
580 | * MGTK[variable] || Key RSC[8] || GTKExpirationTime[4] | |
581 | */ | |
582 | os_memcpy(pos, rsn->mgtk, rsn->mgtk_len); | |
583 | pos += rsn->mgtk_len; | |
584 | wpa_drv_get_seqnum(rsn->wpa_s, NULL, rsn->mgtk_key_id, pos); | |
585 | pos += WPA_KEY_RSC_LEN; | |
586 | /* Use fixed GTKExpirationTime for now */ | |
587 | WPA_PUT_LE32(pos, 0xffffffff); | |
588 | pos += 4; | |
589 | ||
f868d560 JM |
590 | /* |
591 | * IGTKdata[variable]: | |
592 | * Key ID[2], IPN[6], IGTK[variable] | |
593 | */ | |
594 | if (rsn->igtk_len) { | |
595 | WPA_PUT_LE16(pos, rsn->igtk_key_id); | |
596 | pos += 2; | |
597 | wpa_drv_get_seqnum(rsn->wpa_s, NULL, rsn->igtk_key_id, pos); | |
598 | pos += 6; | |
599 | os_memcpy(pos, rsn->igtk, rsn->igtk_len); | |
600 | } | |
f868d560 | 601 | |
ee0ad453 | 602 | skip_keys: |
f868d560 JM |
603 | wpa_hexdump_key(MSG_DEBUG, "mesh: Plaintext AMPE element", |
604 | ampe_ie, 2 + len); | |
0f950df0 TP |
605 | |
606 | /* IE: MIC */ | |
f868d560 JM |
607 | wpabuf_put_u8(buf, WLAN_EID_MIC); |
608 | wpabuf_put_u8(buf, AES_BLOCK_SIZE); | |
0f950df0 TP |
609 | /* MIC field is output ciphertext */ |
610 | ||
611 | /* encrypt after MIC */ | |
f868d560 | 612 | mic_payload = wpabuf_put(buf, 2 + len + AES_BLOCK_SIZE); |
0f950df0 | 613 | |
325a85be | 614 | if (aes_siv_encrypt(sta->aek, sizeof(sta->aek), ampe_ie, 2 + len, 3, |
0f950df0 TP |
615 | aad, aad_len, mic_payload)) { |
616 | wpa_printf(MSG_ERROR, "protect frame: failed to encrypt"); | |
617 | ret = -ENOMEM; | |
0f950df0 TP |
618 | } |
619 | ||
0f950df0 | 620 | os_free(ampe_ie); |
0f950df0 TP |
621 | |
622 | return ret; | |
623 | } | |
624 | ||
625 | ||
626 | int mesh_rsn_process_ampe(struct wpa_supplicant *wpa_s, struct sta_info *sta, | |
627 | struct ieee802_11_elems *elems, const u8 *cat, | |
b2817cd5 | 628 | const u8 *chosen_pmk, |
0f950df0 TP |
629 | const u8 *start, size_t elems_len) |
630 | { | |
631 | int ret = 0; | |
632 | struct ieee80211_ampe_ie *ampe; | |
b8b499e4 | 633 | u8 null_nonce[WPA_NONCE_LEN] = {}; |
0f950df0 TP |
634 | u8 ampe_eid; |
635 | u8 ampe_ie_len; | |
f868d560 | 636 | u8 *ampe_buf, *crypt = NULL, *pos, *end; |
0f950df0 TP |
637 | size_t crypt_len; |
638 | const u8 *aad[] = { sta->addr, wpa_s->own_addr, cat }; | |
639 | const size_t aad_len[] = { ETH_ALEN, ETH_ALEN, | |
cc4cdefc | 640 | elems->mic ? (elems->mic - 2) - cat : 0 }; |
f868d560 | 641 | size_t key_len; |
0f950df0 | 642 | |
9f2cf23e MH |
643 | if (!sta->sae) { |
644 | struct hostapd_data *hapd = wpa_s->ifmsh->bss[0]; | |
645 | ||
c1bd4bac | 646 | if (!wpa_auth_pmksa_get(hapd->wpa_auth, sta->addr, NULL)) { |
9f2cf23e MH |
647 | wpa_printf(MSG_INFO, |
648 | "Mesh RSN: SAE is not prepared yet"); | |
649 | return -1; | |
650 | } | |
651 | mesh_rsn_auth_sae_sta(wpa_s, sta); | |
652 | } | |
653 | ||
9571f945 JM |
654 | if (chosen_pmk && |
655 | (!sta->sae || | |
656 | os_memcmp(chosen_pmk, sta->sae->pmkid, PMKID_LEN) != 0)) { | |
b2817cd5 BC |
657 | wpa_msg(wpa_s, MSG_DEBUG, |
658 | "Mesh RSN: Invalid PMKID (Chosen PMK did not match calculated PMKID)"); | |
659 | return -1; | |
660 | } | |
661 | ||
0f950df0 TP |
662 | if (!elems->mic || elems->mic_len < AES_BLOCK_SIZE) { |
663 | wpa_msg(wpa_s, MSG_DEBUG, "Mesh RSN: missing mic ie"); | |
664 | return -1; | |
665 | } | |
666 | ||
667 | ampe_buf = (u8 *) elems->mic + elems->mic_len; | |
668 | if ((int) elems_len < ampe_buf - start) | |
669 | return -1; | |
670 | ||
671 | crypt_len = elems_len - (elems->mic - start); | |
f868d560 | 672 | if (crypt_len < 2 + AES_BLOCK_SIZE) { |
0f950df0 TP |
673 | wpa_msg(wpa_s, MSG_DEBUG, "Mesh RSN: missing ampe ie"); |
674 | return -1; | |
675 | } | |
676 | ||
677 | /* crypt is modified by siv_decrypt */ | |
678 | crypt = os_zalloc(crypt_len); | |
679 | if (!crypt) { | |
680 | wpa_printf(MSG_ERROR, "Mesh RSN: out of memory"); | |
681 | ret = -ENOMEM; | |
682 | goto free; | |
683 | } | |
684 | ||
685 | os_memcpy(crypt, elems->mic, crypt_len); | |
686 | ||
325a85be | 687 | if (aes_siv_decrypt(sta->aek, sizeof(sta->aek), crypt, crypt_len, 3, |
0f950df0 TP |
688 | aad, aad_len, ampe_buf)) { |
689 | wpa_printf(MSG_ERROR, "Mesh RSN: frame verification failed!"); | |
1f2f3f1c | 690 | ret = -2; |
0f950df0 TP |
691 | goto free; |
692 | } | |
693 | ||
f868d560 JM |
694 | crypt_len -= AES_BLOCK_SIZE; |
695 | wpa_hexdump_key(MSG_DEBUG, "mesh: Decrypted AMPE element", | |
696 | ampe_buf, crypt_len); | |
697 | ||
0f950df0 TP |
698 | ampe_eid = *ampe_buf++; |
699 | ampe_ie_len = *ampe_buf++; | |
700 | ||
701 | if (ampe_eid != WLAN_EID_AMPE || | |
f868d560 | 702 | (size_t) 2 + ampe_ie_len > crypt_len || |
0f950df0 TP |
703 | ampe_ie_len < sizeof(struct ieee80211_ampe_ie)) { |
704 | wpa_msg(wpa_s, MSG_DEBUG, "Mesh RSN: invalid ampe ie"); | |
705 | ret = -1; | |
706 | goto free; | |
707 | } | |
708 | ||
709 | ampe = (struct ieee80211_ampe_ie *) ampe_buf; | |
f868d560 JM |
710 | pos = (u8 *) (ampe + 1); |
711 | end = ampe_buf + ampe_ie_len; | |
b8b499e4 JM |
712 | if (os_memcmp(ampe->peer_nonce, null_nonce, WPA_NONCE_LEN) != 0 && |
713 | os_memcmp(ampe->peer_nonce, sta->my_nonce, WPA_NONCE_LEN) != 0) { | |
0f950df0 TP |
714 | wpa_msg(wpa_s, MSG_DEBUG, "Mesh RSN: invalid peer nonce"); |
715 | ret = -1; | |
716 | goto free; | |
717 | } | |
718 | os_memcpy(sta->peer_nonce, ampe->local_nonce, | |
719 | sizeof(ampe->local_nonce)); | |
0f950df0 | 720 | |
f868d560 JM |
721 | /* TODO: Key Replay Counter[8] in Mesh Group Key Inform/Acknowledge |
722 | * frames */ | |
723 | ||
ee0ad453 JM |
724 | /* |
725 | * GTKdata shall not be included in Mesh Peering Confirm. While the | |
726 | * standard does not state the same about IGTKdata, that same constraint | |
727 | * needs to apply for it. It makes no sense to include the keys in Mesh | |
728 | * Peering Close frames either, so while the standard does not seem to | |
729 | * have a shall statement for these, they are described without | |
730 | * mentioning GTKdata. | |
731 | * | |
732 | * An earlier implementation used to add GTKdata to both Mesh Peering | |
733 | * Open and Mesh Peering Confirm frames, so ignore the possibly present | |
734 | * GTKdata frame without rejecting the frame as a backwards | |
735 | * compatibility mechanism. | |
736 | */ | |
737 | if (cat[1] != PLINK_OPEN) { | |
738 | if (end > pos) { | |
739 | wpa_hexdump_key(MSG_DEBUG, | |
740 | "mesh: Ignore unexpected GTKdata(etc.) fields in the end of AMPE element in Mesh Peering Confirm/Close", | |
741 | pos, end - pos); | |
742 | } | |
743 | goto free; | |
744 | } | |
745 | ||
f868d560 JM |
746 | /* |
747 | * GTKdata[variable]: | |
748 | * MGTK[variable] || Key RSC[8] || GTKExpirationTime[4] | |
749 | */ | |
3b6deac0 JM |
750 | sta->mgtk_key_id = 1; /* FIX: Where to get Key ID? */ |
751 | key_len = wpa_cipher_key_len(wpa_s->mesh_rsn->group_cipher); | |
f868d560 JM |
752 | if ((int) key_len + WPA_KEY_RSC_LEN + 4 > end - pos) { |
753 | wpa_dbg(wpa_s, MSG_DEBUG, "mesh: Truncated AMPE element"); | |
754 | ret = -1; | |
755 | goto free; | |
756 | } | |
757 | sta->mgtk_len = key_len; | |
758 | os_memcpy(sta->mgtk, pos, sta->mgtk_len); | |
759 | wpa_hexdump_key(MSG_DEBUG, "mesh: GTKdata - MGTK", | |
760 | sta->mgtk, sta->mgtk_len); | |
761 | pos += sta->mgtk_len; | |
762 | wpa_hexdump(MSG_DEBUG, "mesh: GTKdata - MGTK - Key RSC", | |
763 | pos, WPA_KEY_RSC_LEN); | |
764 | os_memcpy(sta->mgtk_rsc, pos, sizeof(sta->mgtk_rsc)); | |
765 | pos += WPA_KEY_RSC_LEN; | |
766 | wpa_printf(MSG_DEBUG, | |
767 | "mesh: GTKdata - MGTK - GTKExpirationTime: %u seconds", | |
768 | WPA_GET_LE32(pos)); | |
769 | pos += 4; | |
770 | ||
f868d560 JM |
771 | /* |
772 | * IGTKdata[variable]: | |
773 | * Key ID[2], IPN[6], IGTK[variable] | |
774 | */ | |
3b6deac0 | 775 | key_len = wpa_cipher_key_len(wpa_s->mesh_rsn->mgmt_group_cipher); |
f868d560 JM |
776 | if (end - pos >= (int) (2 + 6 + key_len)) { |
777 | sta->igtk_key_id = WPA_GET_LE16(pos); | |
778 | wpa_printf(MSG_DEBUG, "mesh: IGTKdata - Key ID %u", | |
779 | sta->igtk_key_id); | |
780 | pos += 2; | |
781 | os_memcpy(sta->igtk_rsc, pos, sizeof(sta->igtk_rsc)); | |
782 | wpa_hexdump(MSG_DEBUG, "mesh: IGTKdata - IPN", | |
783 | sta->igtk_rsc, sizeof(sta->igtk_rsc)); | |
784 | pos += 6; | |
785 | os_memcpy(sta->igtk, pos, key_len); | |
786 | sta->igtk_len = key_len; | |
787 | wpa_hexdump_key(MSG_DEBUG, "mesh: IGTKdata - IGTK", | |
788 | sta->igtk, sta->igtk_len); | |
789 | } | |
f868d560 | 790 | |
0f950df0 TP |
791 | free: |
792 | os_free(crypt); | |
793 | return ret; | |
794 | } |