]>
Commit | Line | Data |
---|---|---|
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, | |
103 | const u8 *addr, int idx, u8 *key, size_t key_len) | |
104 | { | |
105 | struct mesh_rsn *mesh_rsn = ctx; | |
106 | u8 seq[6]; | |
107 | ||
108 | os_memset(seq, 0, sizeof(seq)); | |
109 | ||
110 | if (addr) { | |
111 | wpa_printf(MSG_DEBUG, "AUTH: %s(alg=%d addr=" MACSTR | |
112 | " key_idx=%d)", | |
113 | __func__, alg, MAC2STR(addr), idx); | |
114 | } else { | |
115 | wpa_printf(MSG_DEBUG, "AUTH: %s(alg=%d key_idx=%d)", | |
116 | __func__, alg, idx); | |
117 | } | |
118 | wpa_hexdump_key(MSG_DEBUG, "AUTH: set_key - key", key, key_len); | |
119 | ||
120 | return wpa_drv_set_key(mesh_rsn->wpa_s, alg, addr, idx, | |
121 | 1, seq, 6, key, key_len); | |
122 | } | |
123 | ||
124 | ||
125 | static int auth_start_ampe(void *ctx, const u8 *addr) | |
126 | { | |
127 | struct mesh_rsn *mesh_rsn = ctx; | |
c596f3f0 CYY |
128 | struct hostapd_data *hapd; |
129 | struct sta_info *sta; | |
0f950df0 TP |
130 | |
131 | if (mesh_rsn->wpa_s->current_ssid->mode != WPAS_MODE_MESH) | |
132 | return -1; | |
133 | ||
c596f3f0 CYY |
134 | hapd = mesh_rsn->wpa_s->ifmsh->bss[0]; |
135 | sta = ap_get_sta(hapd, addr); | |
136 | if (sta) | |
137 | eloop_cancel_timeout(mesh_auth_timer, mesh_rsn->wpa_s, sta); | |
138 | ||
0f950df0 TP |
139 | mesh_mpm_auth_peer(mesh_rsn->wpa_s, addr); |
140 | return 0; | |
141 | } | |
142 | ||
143 | ||
18aca1a0 | 144 | static int __mesh_rsn_auth_init(struct mesh_rsn *rsn, const u8 *addr, |
716ed96e | 145 | enum mfp_options ieee80211w, int ocv) |
0f950df0 TP |
146 | { |
147 | struct wpa_auth_config conf; | |
cef8fac0 JB |
148 | static const struct wpa_auth_callbacks cb = { |
149 | .logger = auth_logger, | |
150 | .get_psk = auth_get_psk, | |
151 | .set_key = auth_set_key, | |
152 | .start_ampe = auth_start_ampe, | |
153 | }; | |
0f950df0 TP |
154 | u8 seq[6] = {}; |
155 | ||
156 | wpa_printf(MSG_DEBUG, "AUTH: Initializing group state machine"); | |
157 | ||
158 | os_memset(&conf, 0, sizeof(conf)); | |
3b6deac0 | 159 | conf.wpa = WPA_PROTO_RSN; |
0f950df0 | 160 | conf.wpa_key_mgmt = WPA_KEY_MGMT_SAE; |
3b6deac0 JM |
161 | conf.wpa_pairwise = rsn->pairwise_cipher; |
162 | conf.rsn_pairwise = rsn->pairwise_cipher; | |
163 | conf.wpa_group = rsn->group_cipher; | |
0f950df0 TP |
164 | conf.eapol_version = 0; |
165 | conf.wpa_group_rekey = -1; | |
41f140d3 GK |
166 | conf.wpa_group_update_count = 4; |
167 | conf.wpa_pairwise_update_count = 4; | |
18aca1a0 JM |
168 | #ifdef CONFIG_IEEE80211W |
169 | conf.ieee80211w = ieee80211w; | |
170 | if (ieee80211w != NO_MGMT_FRAME_PROTECTION) | |
3b6deac0 | 171 | conf.group_mgmt_cipher = rsn->mgmt_group_cipher; |
18aca1a0 | 172 | #endif /* CONFIG_IEEE80211W */ |
716ed96e MV |
173 | #ifdef CONFIG_OCV |
174 | conf.ocv = ocv; | |
175 | #endif /* CONFIG_OCV */ | |
0f950df0 | 176 | |
cef8fac0 | 177 | rsn->auth = wpa_init(addr, &conf, &cb, rsn); |
0f950df0 TP |
178 | if (rsn->auth == NULL) { |
179 | wpa_printf(MSG_DEBUG, "AUTH: wpa_init() failed"); | |
180 | return -1; | |
181 | } | |
182 | ||
183 | /* TODO: support rekeying */ | |
3b6deac0 | 184 | rsn->mgtk_len = wpa_cipher_key_len(conf.wpa_group); |
696f7923 | 185 | if (random_get_bytes(rsn->mgtk, rsn->mgtk_len) < 0) |
0f950df0 | 186 | return -1; |
f868d560 | 187 | rsn->mgtk_key_id = 1; |
0f950df0 | 188 | |
fccba2c9 JM |
189 | #ifdef CONFIG_IEEE80211W |
190 | if (ieee80211w != NO_MGMT_FRAME_PROTECTION) { | |
3b6deac0 | 191 | rsn->igtk_len = wpa_cipher_key_len(conf.group_mgmt_cipher); |
f868d560 | 192 | if (random_get_bytes(rsn->igtk, rsn->igtk_len) < 0) |
fccba2c9 | 193 | return -1; |
f868d560 | 194 | rsn->igtk_key_id = 4; |
fccba2c9 JM |
195 | |
196 | /* group mgmt */ | |
197 | wpa_hexdump_key(MSG_DEBUG, "mesh: Own TX IGTK", | |
198 | rsn->igtk, rsn->igtk_len); | |
3b6deac0 JM |
199 | wpa_drv_set_key(rsn->wpa_s, |
200 | wpa_cipher_to_alg(rsn->mgmt_group_cipher), NULL, | |
f868d560 | 201 | rsn->igtk_key_id, 1, |
fccba2c9 JM |
202 | seq, sizeof(seq), rsn->igtk, rsn->igtk_len); |
203 | } | |
204 | #endif /* CONFIG_IEEE80211W */ | |
0f950df0 TP |
205 | |
206 | /* group privacy / data frames */ | |
696f7923 JM |
207 | wpa_hexdump_key(MSG_DEBUG, "mesh: Own TX MGTK", |
208 | rsn->mgtk, rsn->mgtk_len); | |
3b6deac0 JM |
209 | wpa_drv_set_key(rsn->wpa_s, wpa_cipher_to_alg(rsn->group_cipher), NULL, |
210 | rsn->mgtk_key_id, 1, seq, sizeof(seq), | |
211 | rsn->mgtk, rsn->mgtk_len); | |
0f950df0 TP |
212 | |
213 | return 0; | |
214 | } | |
215 | ||
216 | ||
217 | static void mesh_rsn_deinit(struct mesh_rsn *rsn) | |
218 | { | |
219 | os_memset(rsn->mgtk, 0, sizeof(rsn->mgtk)); | |
696f7923 | 220 | rsn->mgtk_len = 0; |
fccba2c9 JM |
221 | os_memset(rsn->igtk, 0, sizeof(rsn->igtk)); |
222 | rsn->igtk_len = 0; | |
a5d2bf24 MH |
223 | if (rsn->auth) |
224 | wpa_deinit(rsn->auth); | |
0f950df0 TP |
225 | } |
226 | ||
227 | ||
228 | struct mesh_rsn *mesh_rsn_auth_init(struct wpa_supplicant *wpa_s, | |
229 | struct mesh_conf *conf) | |
230 | { | |
231 | struct mesh_rsn *mesh_rsn; | |
232 | struct hostapd_data *bss = wpa_s->ifmsh->bss[0]; | |
233 | const u8 *ie; | |
234 | size_t ie_len; | |
4d77d80e MH |
235 | #ifdef CONFIG_PMKSA_CACHE_EXTERNAL |
236 | struct external_pmksa_cache *entry; | |
237 | #endif /* CONFIG_PMKSA_CACHE_EXTERNAL */ | |
0f950df0 TP |
238 | |
239 | mesh_rsn = os_zalloc(sizeof(*mesh_rsn)); | |
240 | if (mesh_rsn == NULL) | |
241 | return NULL; | |
242 | mesh_rsn->wpa_s = wpa_s; | |
3b6deac0 JM |
243 | mesh_rsn->pairwise_cipher = conf->pairwise_cipher; |
244 | mesh_rsn->group_cipher = conf->group_cipher; | |
245 | mesh_rsn->mgmt_group_cipher = conf->mgmt_group_cipher; | |
0f950df0 | 246 | |
18aca1a0 | 247 | if (__mesh_rsn_auth_init(mesh_rsn, wpa_s->own_addr, |
716ed96e | 248 | conf->ieee80211w, conf->ocv) < 0) { |
0f950df0 | 249 | mesh_rsn_deinit(mesh_rsn); |
449d63d6 | 250 | os_free(mesh_rsn); |
0f950df0 TP |
251 | return NULL; |
252 | } | |
253 | ||
254 | bss->wpa_auth = mesh_rsn->auth; | |
255 | ||
4d77d80e MH |
256 | #ifdef CONFIG_PMKSA_CACHE_EXTERNAL |
257 | while ((entry = dl_list_last(&wpa_s->mesh_external_pmksa_cache, | |
258 | struct external_pmksa_cache, | |
259 | list)) != NULL) { | |
260 | int ret; | |
261 | ||
262 | ret = wpa_auth_pmksa_add_entry(bss->wpa_auth, | |
263 | entry->pmksa_cache); | |
264 | dl_list_del(&entry->list); | |
265 | os_free(entry); | |
266 | ||
267 | if (ret < 0) | |
268 | return NULL; | |
269 | } | |
270 | #endif /* CONFIG_PMKSA_CACHE_EXTERNAL */ | |
271 | ||
0f950df0 | 272 | ie = wpa_auth_get_wpa_ie(mesh_rsn->auth, &ie_len); |
8a51dcbc MH |
273 | conf->rsn_ie = (u8 *) ie; |
274 | conf->rsn_ie_len = ie_len; | |
0f950df0 TP |
275 | |
276 | wpa_supplicant_rsn_supp_set_config(wpa_s, wpa_s->current_ssid); | |
277 | ||
278 | return mesh_rsn; | |
279 | } | |
280 | ||
281 | ||
282 | static int index_within_array(const int *array, int idx) | |
283 | { | |
284 | int i; | |
285 | ||
286 | for (i = 0; i < idx; i++) { | |
287 | if (array[i] == -1) | |
288 | return 0; | |
289 | } | |
290 | ||
291 | return 1; | |
292 | } | |
293 | ||
294 | ||
295 | static int mesh_rsn_sae_group(struct wpa_supplicant *wpa_s, | |
296 | struct sae_data *sae) | |
297 | { | |
298 | int *groups = wpa_s->ifmsh->bss[0]->conf->sae_groups; | |
299 | ||
300 | /* Configuration may have changed, so validate current index */ | |
301 | if (!index_within_array(groups, wpa_s->mesh_rsn->sae_group_index)) | |
302 | return -1; | |
303 | ||
304 | for (;;) { | |
305 | int group = groups[wpa_s->mesh_rsn->sae_group_index]; | |
306 | ||
307 | if (group <= 0) | |
308 | break; | |
309 | if (sae_set_group(sae, group) == 0) { | |
310 | wpa_dbg(wpa_s, MSG_DEBUG, "SME: Selected SAE group %d", | |
311 | sae->group); | |
312 | return 0; | |
313 | } | |
314 | wpa_s->mesh_rsn->sae_group_index++; | |
315 | } | |
316 | ||
317 | return -1; | |
318 | } | |
319 | ||
320 | ||
a206e2a1 BC |
321 | static int mesh_rsn_build_sae_commit(struct wpa_supplicant *wpa_s, |
322 | struct wpa_ssid *ssid, | |
323 | struct sta_info *sta) | |
0f950df0 | 324 | { |
a34ca59e JM |
325 | const char *password; |
326 | ||
327 | password = ssid->sae_password; | |
328 | if (!password) | |
329 | password = ssid->passphrase; | |
330 | if (!password) { | |
0f950df0 | 331 | wpa_msg(wpa_s, MSG_DEBUG, "SAE: No password available"); |
a206e2a1 | 332 | return -1; |
0f950df0 TP |
333 | } |
334 | ||
335 | if (mesh_rsn_sae_group(wpa_s, sta->sae) < 0) { | |
336 | wpa_msg(wpa_s, MSG_DEBUG, "SAE: Failed to select group"); | |
a206e2a1 | 337 | return -1; |
0f950df0 TP |
338 | } |
339 | ||
9be19d0b JM |
340 | if (sta->sae->tmp && !sta->sae->tmp->pw_id && ssid->sae_password_id) { |
341 | sta->sae->tmp->pw_id = os_strdup(ssid->sae_password_id); | |
342 | if (!sta->sae->tmp->pw_id) | |
343 | return -1; | |
344 | } | |
a206e2a1 | 345 | return sae_prepare_commit(wpa_s->own_addr, sta->addr, |
a34ca59e | 346 | (u8 *) password, os_strlen(password), |
9be19d0b | 347 | ssid->sae_password_id, |
a34ca59e | 348 | sta->sae); |
0f950df0 TP |
349 | } |
350 | ||
351 | ||
352 | /* initiate new SAE authentication with sta */ | |
353 | int mesh_rsn_auth_sae_sta(struct wpa_supplicant *wpa_s, | |
354 | struct sta_info *sta) | |
355 | { | |
a206e2a1 | 356 | struct hostapd_data *hapd = wpa_s->ifmsh->bss[0]; |
0f950df0 | 357 | struct wpa_ssid *ssid = wpa_s->current_ssid; |
9f2cf23e | 358 | struct rsn_pmksa_cache_entry *pmksa; |
c596f3f0 | 359 | unsigned int rnd; |
a206e2a1 | 360 | int ret; |
0f950df0 | 361 | |
608b0ff5 JM |
362 | if (!ssid) { |
363 | wpa_msg(wpa_s, MSG_DEBUG, | |
364 | "AUTH: No current_ssid known to initiate new SAE"); | |
365 | return -1; | |
366 | } | |
367 | ||
0f950df0 TP |
368 | if (!sta->sae) { |
369 | sta->sae = os_zalloc(sizeof(*sta->sae)); | |
370 | if (sta->sae == NULL) | |
371 | return -1; | |
372 | } | |
373 | ||
c1bd4bac | 374 | pmksa = wpa_auth_pmksa_get(hapd->wpa_auth, sta->addr, NULL); |
9f2cf23e MH |
375 | if (pmksa) { |
376 | if (!sta->wpa_sm) | |
377 | sta->wpa_sm = wpa_auth_sta_init(hapd->wpa_auth, | |
378 | sta->addr, NULL); | |
379 | if (!sta->wpa_sm) { | |
380 | wpa_printf(MSG_ERROR, | |
381 | "mesh: Failed to initialize RSN state machine"); | |
382 | return -1; | |
383 | } | |
384 | ||
385 | wpa_printf(MSG_DEBUG, | |
386 | "AUTH: Mesh PMKSA cache entry found for " MACSTR | |
387 | " - try to use PMKSA caching instead of new SAE authentication", | |
388 | MAC2STR(sta->addr)); | |
389 | wpa_auth_pmksa_set_to_sm(pmksa, sta->wpa_sm, hapd->wpa_auth, | |
390 | sta->sae->pmkid, sta->sae->pmk); | |
391 | sae_accept_sta(hapd, sta); | |
392 | sta->mesh_sae_pmksa_caching = 1; | |
393 | return 0; | |
394 | } | |
395 | sta->mesh_sae_pmksa_caching = 0; | |
396 | ||
a206e2a1 | 397 | if (mesh_rsn_build_sae_commit(wpa_s, ssid, sta)) |
0f950df0 TP |
398 | return -1; |
399 | ||
400 | wpa_msg(wpa_s, MSG_DEBUG, | |
401 | "AUTH: started authentication with SAE peer: " MACSTR, | |
402 | MAC2STR(sta->addr)); | |
403 | ||
a206e2a1 BC |
404 | ret = auth_sae_init_committed(hapd, sta); |
405 | if (ret) | |
406 | return ret; | |
0f950df0 | 407 | |
bf51f4f8 | 408 | eloop_cancel_timeout(mesh_auth_timer, wpa_s, sta); |
c596f3f0 CYY |
409 | rnd = rand() % MESH_AUTH_TIMEOUT; |
410 | eloop_register_timeout(MESH_AUTH_TIMEOUT + rnd, 0, mesh_auth_timer, | |
411 | wpa_s, sta); | |
0f950df0 TP |
412 | return 0; |
413 | } | |
414 | ||
415 | ||
416 | void mesh_rsn_get_pmkid(struct mesh_rsn *rsn, struct sta_info *sta, u8 *pmkid) | |
417 | { | |
6c33eed3 | 418 | os_memcpy(pmkid, sta->sae->pmkid, SAE_PMKID_LEN); |
0f950df0 TP |
419 | } |
420 | ||
421 | ||
422 | static void | |
423 | mesh_rsn_derive_aek(struct mesh_rsn *rsn, struct sta_info *sta) | |
424 | { | |
425 | u8 *myaddr = rsn->wpa_s->own_addr; | |
426 | u8 *peer = sta->addr; | |
f5ba6923 JM |
427 | u8 *addr1, *addr2; |
428 | u8 context[RSN_SELECTOR_LEN + 2 * ETH_ALEN], *ptr = context; | |
0f950df0 | 429 | |
f5ba6923 JM |
430 | /* |
431 | * AEK = KDF-Hash-256(PMK, "AEK Derivation", Selected AKM Suite || | |
432 | * min(localMAC, peerMAC) || max(localMAC, peerMAC)) | |
433 | */ | |
a59c5e92 | 434 | /* Selected AKM Suite: SAE */ |
f5ba6923 JM |
435 | RSN_SELECTOR_PUT(ptr, RSN_AUTH_KEY_MGMT_SAE); |
436 | ptr += RSN_SELECTOR_LEN; | |
0f950df0 TP |
437 | |
438 | if (os_memcmp(myaddr, peer, ETH_ALEN) < 0) { | |
439 | addr1 = myaddr; | |
440 | addr2 = peer; | |
f5ba6923 JM |
441 | } else { |
442 | addr1 = peer; | |
443 | addr2 = myaddr; | |
0f950df0 | 444 | } |
f5ba6923 JM |
445 | os_memcpy(ptr, addr1, ETH_ALEN); |
446 | ptr += ETH_ALEN; | |
447 | os_memcpy(ptr, addr2, ETH_ALEN); | |
0f950df0 TP |
448 | |
449 | sha256_prf(sta->sae->pmk, sizeof(sta->sae->pmk), "AEK Derivation", | |
450 | context, sizeof(context), sta->aek, sizeof(sta->aek)); | |
451 | } | |
452 | ||
453 | ||
454 | /* derive mesh temporal key from pmk */ | |
455 | int mesh_rsn_derive_mtk(struct wpa_supplicant *wpa_s, struct sta_info *sta) | |
456 | { | |
457 | u8 *ptr; | |
458 | u8 *min, *max; | |
0f950df0 TP |
459 | u8 *myaddr = wpa_s->own_addr; |
460 | u8 *peer = sta->addr; | |
846201df | 461 | u8 context[2 * WPA_NONCE_LEN + 2 * 2 + RSN_SELECTOR_LEN + 2 * ETH_ALEN]; |
0f950df0 | 462 | |
846201df JM |
463 | /* |
464 | * MTK = KDF-Hash-Length(PMK, "Temporal Key Derivation", min(localNonce, | |
465 | * peerNonce) || max(localNonce, peerNonce) || min(localLinkID, | |
466 | * peerLinkID) || max(localLinkID, peerLinkID) || Selected AKM Suite || | |
467 | * min(localMAC, peerMAC) || max(localMAC, peerMAC)) | |
468 | */ | |
0f950df0 | 469 | ptr = context; |
b8b499e4 | 470 | if (os_memcmp(sta->my_nonce, sta->peer_nonce, WPA_NONCE_LEN) < 0) { |
0f950df0 TP |
471 | min = sta->my_nonce; |
472 | max = sta->peer_nonce; | |
473 | } else { | |
474 | min = sta->peer_nonce; | |
475 | max = sta->my_nonce; | |
476 | } | |
b8b499e4 | 477 | os_memcpy(ptr, min, WPA_NONCE_LEN); |
846201df JM |
478 | ptr += WPA_NONCE_LEN; |
479 | os_memcpy(ptr, max, WPA_NONCE_LEN); | |
480 | ptr += WPA_NONCE_LEN; | |
0f950df0 TP |
481 | |
482 | if (sta->my_lid < sta->peer_lid) { | |
846201df JM |
483 | WPA_PUT_LE16(ptr, sta->my_lid); |
484 | ptr += 2; | |
485 | WPA_PUT_LE16(ptr, sta->peer_lid); | |
486 | ptr += 2; | |
0f950df0 | 487 | } else { |
846201df JM |
488 | WPA_PUT_LE16(ptr, sta->peer_lid); |
489 | ptr += 2; | |
490 | WPA_PUT_LE16(ptr, sta->my_lid); | |
491 | ptr += 2; | |
0f950df0 | 492 | } |
0f950df0 | 493 | |
0f76d824 JM |
494 | /* Selected AKM Suite: SAE */ |
495 | RSN_SELECTOR_PUT(ptr, RSN_AUTH_KEY_MGMT_SAE); | |
846201df | 496 | ptr += RSN_SELECTOR_LEN; |
0f950df0 TP |
497 | |
498 | if (os_memcmp(myaddr, peer, ETH_ALEN) < 0) { | |
499 | min = myaddr; | |
500 | max = peer; | |
501 | } else { | |
502 | min = peer; | |
503 | max = myaddr; | |
504 | } | |
505 | os_memcpy(ptr, min, ETH_ALEN); | |
846201df JM |
506 | ptr += ETH_ALEN; |
507 | os_memcpy(ptr, max, ETH_ALEN); | |
0f950df0 | 508 | |
3b6deac0 | 509 | sta->mtk_len = wpa_cipher_key_len(wpa_s->mesh_rsn->pairwise_cipher); |
846201df | 510 | sha256_prf(sta->sae->pmk, SAE_PMK_LEN, |
0f950df0 | 511 | "Temporal Key Derivation", context, sizeof(context), |
b02f4d05 | 512 | sta->mtk, sta->mtk_len); |
0f950df0 TP |
513 | return 0; |
514 | } | |
515 | ||
516 | ||
517 | void mesh_rsn_init_ampe_sta(struct wpa_supplicant *wpa_s, struct sta_info *sta) | |
518 | { | |
b8b499e4 | 519 | if (random_get_bytes(sta->my_nonce, WPA_NONCE_LEN) < 0) { |
0f950df0 TP |
520 | wpa_printf(MSG_INFO, "mesh: Failed to derive random nonce"); |
521 | /* TODO: How to handle this more cleanly? */ | |
522 | } | |
b8b499e4 | 523 | os_memset(sta->peer_nonce, 0, WPA_NONCE_LEN); |
0f950df0 TP |
524 | mesh_rsn_derive_aek(wpa_s->mesh_rsn, sta); |
525 | } | |
526 | ||
527 | ||
528 | /* insert AMPE and encrypted MIC at @ie. | |
529 | * @mesh_rsn: mesh RSN context | |
530 | * @sta: STA we're sending to | |
531 | * @cat: pointer to category code in frame header. | |
532 | * @buf: wpabuf to add encrypted AMPE and MIC to. | |
533 | * */ | |
534 | int mesh_rsn_protect_frame(struct mesh_rsn *rsn, struct sta_info *sta, | |
535 | const u8 *cat, struct wpabuf *buf) | |
536 | { | |
537 | struct ieee80211_ampe_ie *ampe; | |
538 | u8 const *ie = wpabuf_head_u8(buf) + wpabuf_len(buf); | |
f868d560 | 539 | u8 *ampe_ie, *pos, *mic_payload; |
0f950df0 TP |
540 | const u8 *aad[] = { rsn->wpa_s->own_addr, sta->addr, cat }; |
541 | const size_t aad_len[] = { ETH_ALEN, ETH_ALEN, ie - cat }; | |
542 | int ret = 0; | |
f868d560 | 543 | size_t len; |
0f950df0 | 544 | |
ee0ad453 JM |
545 | len = sizeof(*ampe); |
546 | if (cat[1] == PLINK_OPEN) | |
547 | len += rsn->mgtk_len + WPA_KEY_RSC_LEN + 4; | |
f868d560 | 548 | #ifdef CONFIG_IEEE80211W |
ee0ad453 | 549 | if (cat[1] == PLINK_OPEN && rsn->igtk_len) |
f868d560 JM |
550 | len += 2 + 6 + rsn->igtk_len; |
551 | #endif /* CONFIG_IEEE80211W */ | |
552 | ||
553 | if (2 + AES_BLOCK_SIZE + 2 + len > wpabuf_tailroom(buf)) { | |
0f950df0 TP |
554 | wpa_printf(MSG_ERROR, "protect frame: buffer too small"); |
555 | return -EINVAL; | |
556 | } | |
557 | ||
f868d560 | 558 | ampe_ie = os_zalloc(2 + len); |
0f950df0 TP |
559 | if (!ampe_ie) { |
560 | wpa_printf(MSG_ERROR, "protect frame: out of memory"); | |
561 | return -ENOMEM; | |
562 | } | |
563 | ||
0f950df0 TP |
564 | /* IE: AMPE */ |
565 | ampe_ie[0] = WLAN_EID_AMPE; | |
f868d560 | 566 | ampe_ie[1] = len; |
0f950df0 TP |
567 | ampe = (struct ieee80211_ampe_ie *) (ampe_ie + 2); |
568 | ||
569 | RSN_SELECTOR_PUT(ampe->selected_pairwise_suite, | |
f868d560 | 570 | RSN_CIPHER_SUITE_CCMP); |
b8b499e4 JM |
571 | os_memcpy(ampe->local_nonce, sta->my_nonce, WPA_NONCE_LEN); |
572 | os_memcpy(ampe->peer_nonce, sta->peer_nonce, WPA_NONCE_LEN); | |
f868d560 JM |
573 | |
574 | pos = (u8 *) (ampe + 1); | |
ee0ad453 JM |
575 | if (cat[1] != PLINK_OPEN) |
576 | goto skip_keys; | |
f868d560 JM |
577 | |
578 | /* TODO: Key Replay Counter[8] optionally for | |
579 | * Mesh Group Key Inform/Acknowledge frames */ | |
580 | ||
0f950df0 | 581 | /* TODO: static mgtk for now since we don't support rekeying! */ |
f868d560 JM |
582 | /* |
583 | * GTKdata[variable]: | |
584 | * MGTK[variable] || Key RSC[8] || GTKExpirationTime[4] | |
585 | */ | |
586 | os_memcpy(pos, rsn->mgtk, rsn->mgtk_len); | |
587 | pos += rsn->mgtk_len; | |
588 | wpa_drv_get_seqnum(rsn->wpa_s, NULL, rsn->mgtk_key_id, pos); | |
589 | pos += WPA_KEY_RSC_LEN; | |
590 | /* Use fixed GTKExpirationTime for now */ | |
591 | WPA_PUT_LE32(pos, 0xffffffff); | |
592 | pos += 4; | |
593 | ||
594 | #ifdef CONFIG_IEEE80211W | |
595 | /* | |
596 | * IGTKdata[variable]: | |
597 | * Key ID[2], IPN[6], IGTK[variable] | |
598 | */ | |
599 | if (rsn->igtk_len) { | |
600 | WPA_PUT_LE16(pos, rsn->igtk_key_id); | |
601 | pos += 2; | |
602 | wpa_drv_get_seqnum(rsn->wpa_s, NULL, rsn->igtk_key_id, pos); | |
603 | pos += 6; | |
604 | os_memcpy(pos, rsn->igtk, rsn->igtk_len); | |
605 | } | |
606 | #endif /* CONFIG_IEEE80211W */ | |
607 | ||
ee0ad453 | 608 | skip_keys: |
f868d560 JM |
609 | wpa_hexdump_key(MSG_DEBUG, "mesh: Plaintext AMPE element", |
610 | ampe_ie, 2 + len); | |
0f950df0 TP |
611 | |
612 | /* IE: MIC */ | |
f868d560 JM |
613 | wpabuf_put_u8(buf, WLAN_EID_MIC); |
614 | wpabuf_put_u8(buf, AES_BLOCK_SIZE); | |
0f950df0 TP |
615 | /* MIC field is output ciphertext */ |
616 | ||
617 | /* encrypt after MIC */ | |
f868d560 | 618 | mic_payload = wpabuf_put(buf, 2 + len + AES_BLOCK_SIZE); |
0f950df0 | 619 | |
325a85be | 620 | if (aes_siv_encrypt(sta->aek, sizeof(sta->aek), ampe_ie, 2 + len, 3, |
0f950df0 TP |
621 | aad, aad_len, mic_payload)) { |
622 | wpa_printf(MSG_ERROR, "protect frame: failed to encrypt"); | |
623 | ret = -ENOMEM; | |
0f950df0 TP |
624 | } |
625 | ||
0f950df0 | 626 | os_free(ampe_ie); |
0f950df0 TP |
627 | |
628 | return ret; | |
629 | } | |
630 | ||
631 | ||
632 | int mesh_rsn_process_ampe(struct wpa_supplicant *wpa_s, struct sta_info *sta, | |
633 | struct ieee802_11_elems *elems, const u8 *cat, | |
b2817cd5 | 634 | const u8 *chosen_pmk, |
0f950df0 TP |
635 | const u8 *start, size_t elems_len) |
636 | { | |
637 | int ret = 0; | |
638 | struct ieee80211_ampe_ie *ampe; | |
b8b499e4 | 639 | u8 null_nonce[WPA_NONCE_LEN] = {}; |
0f950df0 TP |
640 | u8 ampe_eid; |
641 | u8 ampe_ie_len; | |
f868d560 | 642 | u8 *ampe_buf, *crypt = NULL, *pos, *end; |
0f950df0 TP |
643 | size_t crypt_len; |
644 | const u8 *aad[] = { sta->addr, wpa_s->own_addr, cat }; | |
645 | const size_t aad_len[] = { ETH_ALEN, ETH_ALEN, | |
cc4cdefc | 646 | elems->mic ? (elems->mic - 2) - cat : 0 }; |
f868d560 | 647 | size_t key_len; |
0f950df0 | 648 | |
9f2cf23e MH |
649 | if (!sta->sae) { |
650 | struct hostapd_data *hapd = wpa_s->ifmsh->bss[0]; | |
651 | ||
c1bd4bac | 652 | if (!wpa_auth_pmksa_get(hapd->wpa_auth, sta->addr, NULL)) { |
9f2cf23e MH |
653 | wpa_printf(MSG_INFO, |
654 | "Mesh RSN: SAE is not prepared yet"); | |
655 | return -1; | |
656 | } | |
657 | mesh_rsn_auth_sae_sta(wpa_s, sta); | |
658 | } | |
659 | ||
9571f945 JM |
660 | if (chosen_pmk && |
661 | (!sta->sae || | |
662 | os_memcmp(chosen_pmk, sta->sae->pmkid, PMKID_LEN) != 0)) { | |
b2817cd5 BC |
663 | wpa_msg(wpa_s, MSG_DEBUG, |
664 | "Mesh RSN: Invalid PMKID (Chosen PMK did not match calculated PMKID)"); | |
665 | return -1; | |
666 | } | |
667 | ||
0f950df0 TP |
668 | if (!elems->mic || elems->mic_len < AES_BLOCK_SIZE) { |
669 | wpa_msg(wpa_s, MSG_DEBUG, "Mesh RSN: missing mic ie"); | |
670 | return -1; | |
671 | } | |
672 | ||
673 | ampe_buf = (u8 *) elems->mic + elems->mic_len; | |
674 | if ((int) elems_len < ampe_buf - start) | |
675 | return -1; | |
676 | ||
677 | crypt_len = elems_len - (elems->mic - start); | |
f868d560 | 678 | if (crypt_len < 2 + AES_BLOCK_SIZE) { |
0f950df0 TP |
679 | wpa_msg(wpa_s, MSG_DEBUG, "Mesh RSN: missing ampe ie"); |
680 | return -1; | |
681 | } | |
682 | ||
683 | /* crypt is modified by siv_decrypt */ | |
684 | crypt = os_zalloc(crypt_len); | |
685 | if (!crypt) { | |
686 | wpa_printf(MSG_ERROR, "Mesh RSN: out of memory"); | |
687 | ret = -ENOMEM; | |
688 | goto free; | |
689 | } | |
690 | ||
691 | os_memcpy(crypt, elems->mic, crypt_len); | |
692 | ||
325a85be | 693 | if (aes_siv_decrypt(sta->aek, sizeof(sta->aek), crypt, crypt_len, 3, |
0f950df0 TP |
694 | aad, aad_len, ampe_buf)) { |
695 | wpa_printf(MSG_ERROR, "Mesh RSN: frame verification failed!"); | |
1f2f3f1c | 696 | ret = -2; |
0f950df0 TP |
697 | goto free; |
698 | } | |
699 | ||
f868d560 JM |
700 | crypt_len -= AES_BLOCK_SIZE; |
701 | wpa_hexdump_key(MSG_DEBUG, "mesh: Decrypted AMPE element", | |
702 | ampe_buf, crypt_len); | |
703 | ||
0f950df0 TP |
704 | ampe_eid = *ampe_buf++; |
705 | ampe_ie_len = *ampe_buf++; | |
706 | ||
707 | if (ampe_eid != WLAN_EID_AMPE || | |
f868d560 | 708 | (size_t) 2 + ampe_ie_len > crypt_len || |
0f950df0 TP |
709 | ampe_ie_len < sizeof(struct ieee80211_ampe_ie)) { |
710 | wpa_msg(wpa_s, MSG_DEBUG, "Mesh RSN: invalid ampe ie"); | |
711 | ret = -1; | |
712 | goto free; | |
713 | } | |
714 | ||
715 | ampe = (struct ieee80211_ampe_ie *) ampe_buf; | |
f868d560 JM |
716 | pos = (u8 *) (ampe + 1); |
717 | end = ampe_buf + ampe_ie_len; | |
b8b499e4 JM |
718 | if (os_memcmp(ampe->peer_nonce, null_nonce, WPA_NONCE_LEN) != 0 && |
719 | os_memcmp(ampe->peer_nonce, sta->my_nonce, WPA_NONCE_LEN) != 0) { | |
0f950df0 TP |
720 | wpa_msg(wpa_s, MSG_DEBUG, "Mesh RSN: invalid peer nonce"); |
721 | ret = -1; | |
722 | goto free; | |
723 | } | |
724 | os_memcpy(sta->peer_nonce, ampe->local_nonce, | |
725 | sizeof(ampe->local_nonce)); | |
0f950df0 | 726 | |
f868d560 JM |
727 | /* TODO: Key Replay Counter[8] in Mesh Group Key Inform/Acknowledge |
728 | * frames */ | |
729 | ||
ee0ad453 JM |
730 | /* |
731 | * GTKdata shall not be included in Mesh Peering Confirm. While the | |
732 | * standard does not state the same about IGTKdata, that same constraint | |
733 | * needs to apply for it. It makes no sense to include the keys in Mesh | |
734 | * Peering Close frames either, so while the standard does not seem to | |
735 | * have a shall statement for these, they are described without | |
736 | * mentioning GTKdata. | |
737 | * | |
738 | * An earlier implementation used to add GTKdata to both Mesh Peering | |
739 | * Open and Mesh Peering Confirm frames, so ignore the possibly present | |
740 | * GTKdata frame without rejecting the frame as a backwards | |
741 | * compatibility mechanism. | |
742 | */ | |
743 | if (cat[1] != PLINK_OPEN) { | |
744 | if (end > pos) { | |
745 | wpa_hexdump_key(MSG_DEBUG, | |
746 | "mesh: Ignore unexpected GTKdata(etc.) fields in the end of AMPE element in Mesh Peering Confirm/Close", | |
747 | pos, end - pos); | |
748 | } | |
749 | goto free; | |
750 | } | |
751 | ||
f868d560 JM |
752 | /* |
753 | * GTKdata[variable]: | |
754 | * MGTK[variable] || Key RSC[8] || GTKExpirationTime[4] | |
755 | */ | |
3b6deac0 JM |
756 | sta->mgtk_key_id = 1; /* FIX: Where to get Key ID? */ |
757 | key_len = wpa_cipher_key_len(wpa_s->mesh_rsn->group_cipher); | |
f868d560 JM |
758 | if ((int) key_len + WPA_KEY_RSC_LEN + 4 > end - pos) { |
759 | wpa_dbg(wpa_s, MSG_DEBUG, "mesh: Truncated AMPE element"); | |
760 | ret = -1; | |
761 | goto free; | |
762 | } | |
763 | sta->mgtk_len = key_len; | |
764 | os_memcpy(sta->mgtk, pos, sta->mgtk_len); | |
765 | wpa_hexdump_key(MSG_DEBUG, "mesh: GTKdata - MGTK", | |
766 | sta->mgtk, sta->mgtk_len); | |
767 | pos += sta->mgtk_len; | |
768 | wpa_hexdump(MSG_DEBUG, "mesh: GTKdata - MGTK - Key RSC", | |
769 | pos, WPA_KEY_RSC_LEN); | |
770 | os_memcpy(sta->mgtk_rsc, pos, sizeof(sta->mgtk_rsc)); | |
771 | pos += WPA_KEY_RSC_LEN; | |
772 | wpa_printf(MSG_DEBUG, | |
773 | "mesh: GTKdata - MGTK - GTKExpirationTime: %u seconds", | |
774 | WPA_GET_LE32(pos)); | |
775 | pos += 4; | |
776 | ||
777 | #ifdef CONFIG_IEEE80211W | |
778 | /* | |
779 | * IGTKdata[variable]: | |
780 | * Key ID[2], IPN[6], IGTK[variable] | |
781 | */ | |
3b6deac0 | 782 | key_len = wpa_cipher_key_len(wpa_s->mesh_rsn->mgmt_group_cipher); |
f868d560 JM |
783 | if (end - pos >= (int) (2 + 6 + key_len)) { |
784 | sta->igtk_key_id = WPA_GET_LE16(pos); | |
785 | wpa_printf(MSG_DEBUG, "mesh: IGTKdata - Key ID %u", | |
786 | sta->igtk_key_id); | |
787 | pos += 2; | |
788 | os_memcpy(sta->igtk_rsc, pos, sizeof(sta->igtk_rsc)); | |
789 | wpa_hexdump(MSG_DEBUG, "mesh: IGTKdata - IPN", | |
790 | sta->igtk_rsc, sizeof(sta->igtk_rsc)); | |
791 | pos += 6; | |
792 | os_memcpy(sta->igtk, pos, key_len); | |
793 | sta->igtk_len = key_len; | |
794 | wpa_hexdump_key(MSG_DEBUG, "mesh: IGTKdata - IGTK", | |
795 | sta->igtk, sta->igtk_len); | |
796 | } | |
797 | #endif /* CONFIG_IEEE80211W */ | |
798 | ||
0f950df0 TP |
799 | free: |
800 | os_free(crypt); | |
801 | return ret; | |
802 | } |