xref: /freebsd/contrib/wpa/src/ap/wpa_auth_kay.c (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
1 /*
2  * IEEE 802.1X-2010 KaY Interface
3  * Copyright (c) 2019, The Linux Foundation
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 "pae/ieee802_1x_key.h"
13 #include "pae/ieee802_1x_kay.h"
14 #include "hostapd.h"
15 #include "sta_info.h"
16 #include "wpa_auth_kay.h"
17 #include "ieee802_1x.h"
18 
19 
20 #define DEFAULT_KEY_LEN		16
21 /* secure Connectivity Association Key Name (CKN) */
22 #define DEFAULT_CKN_LEN		16
23 
24 
25 static int hapd_macsec_init(void *priv, struct macsec_init_params *params)
26 {
27 	struct hostapd_data *hapd = priv;
28 
29 	if (!hapd->driver->macsec_init)
30 		return -1;
31 	return hapd->driver->macsec_init(hapd->drv_priv, params);
32 }
33 
34 
35 static int hapd_macsec_deinit(void *priv)
36 {
37 	struct hostapd_data *hapd = priv;
38 
39 	if (!hapd->driver->macsec_deinit)
40 		return -1;
41 	return hapd->driver->macsec_deinit(hapd->drv_priv);
42 }
43 
44 
45 static int hapd_macsec_get_capability(void *priv, enum macsec_cap *cap)
46 {
47 	struct hostapd_data *hapd = priv;
48 
49 	if (!hapd->driver->macsec_get_capability)
50 		return -1;
51 	return hapd->driver->macsec_get_capability(hapd->drv_priv, cap);
52 }
53 
54 
55 static int hapd_enable_protect_frames(void *priv, bool enabled)
56 {
57 	struct hostapd_data *hapd = priv;
58 
59 	if (!hapd->driver->enable_protect_frames)
60 		return -1;
61 	return hapd->driver->enable_protect_frames(hapd->drv_priv, enabled);
62 }
63 
64 
65 static int hapd_enable_encrypt(void *priv, bool enabled)
66 {
67 	struct hostapd_data *hapd = priv;
68 
69 	if (!hapd->driver->enable_encrypt)
70 		return -1;
71 	return hapd->driver->enable_encrypt(hapd->drv_priv, enabled);
72 }
73 
74 
75 static int hapd_set_replay_protect(void *priv, bool enabled, u32 window)
76 {
77 	struct hostapd_data *hapd = priv;
78 
79 	if (!hapd->driver->set_replay_protect)
80 		return -1;
81 	return hapd->driver->set_replay_protect(hapd->drv_priv, enabled,
82 						 window);
83 }
84 
85 
86 static int hapd_set_current_cipher_suite(void *priv, u64 cs)
87 {
88 	struct hostapd_data *hapd = priv;
89 
90 	if (!hapd->driver->set_current_cipher_suite)
91 		return -1;
92 	return hapd->driver->set_current_cipher_suite(hapd->drv_priv, cs);
93 }
94 
95 
96 static int hapd_enable_controlled_port(void *priv, bool enabled)
97 {
98 	struct hostapd_data *hapd = priv;
99 
100 	if (!hapd->driver->enable_controlled_port)
101 		return -1;
102 	return hapd->driver->enable_controlled_port(hapd->drv_priv, enabled);
103 }
104 
105 
106 static int hapd_get_receive_lowest_pn(void *priv, struct receive_sa *sa)
107 {
108 	struct hostapd_data *hapd = priv;
109 
110 	if (!hapd->driver->get_receive_lowest_pn)
111 		return -1;
112 	return hapd->driver->get_receive_lowest_pn(hapd->drv_priv, sa);
113 }
114 
115 
116 static int hapd_get_transmit_next_pn(void *priv, struct transmit_sa *sa)
117 {
118 	struct hostapd_data *hapd = priv;
119 
120 	if (!hapd->driver->get_transmit_next_pn)
121 		return -1;
122 	return hapd->driver->get_transmit_next_pn(hapd->drv_priv, sa);
123 }
124 
125 
126 static int hapd_set_transmit_next_pn(void *priv, struct transmit_sa *sa)
127 {
128 	struct hostapd_data *hapd = priv;
129 
130 	if (!hapd->driver->set_transmit_next_pn)
131 		return -1;
132 	return hapd->driver->set_transmit_next_pn(hapd->drv_priv, sa);
133 }
134 
135 
136 static unsigned int conf_offset_val(enum confidentiality_offset co)
137 {
138 	switch (co) {
139 	case CONFIDENTIALITY_OFFSET_30:
140 		return 30;
141 		break;
142 	case CONFIDENTIALITY_OFFSET_50:
143 		return 50;
144 	default:
145 		return 0;
146 	}
147 }
148 
149 
150 static int hapd_create_receive_sc(void *priv, struct receive_sc *sc,
151 				  enum validate_frames vf,
152 				  enum confidentiality_offset co)
153 {
154 	struct hostapd_data *hapd = priv;
155 
156 	if (!hapd->driver->create_receive_sc)
157 		return -1;
158 	return hapd->driver->create_receive_sc(hapd->drv_priv, sc,
159 					       conf_offset_val(co), vf);
160 }
161 
162 
163 static int hapd_delete_receive_sc(void *priv, struct receive_sc *sc)
164 {
165 	struct hostapd_data *hapd = priv;
166 
167 	if (!hapd->driver->delete_receive_sc)
168 		return -1;
169 	return hapd->driver->delete_receive_sc(hapd->drv_priv, sc);
170 }
171 
172 
173 static int hapd_create_receive_sa(void *priv, struct receive_sa *sa)
174 {
175 	struct hostapd_data *hapd = priv;
176 
177 	if (!hapd->driver->create_receive_sa)
178 		return -1;
179 	return hapd->driver->create_receive_sa(hapd->drv_priv, sa);
180 }
181 
182 
183 static int hapd_delete_receive_sa(void *priv, struct receive_sa *sa)
184 {
185 	struct hostapd_data *hapd = priv;
186 
187 	if (!hapd->driver->delete_receive_sa)
188 		return -1;
189 	return hapd->driver->delete_receive_sa(hapd->drv_priv, sa);
190 }
191 
192 
193 static int hapd_enable_receive_sa(void *priv, struct receive_sa *sa)
194 {
195 	struct hostapd_data *hapd = priv;
196 
197 	if (!hapd->driver->enable_receive_sa)
198 		return -1;
199 	return hapd->driver->enable_receive_sa(hapd->drv_priv, sa);
200 }
201 
202 
203 static int hapd_disable_receive_sa(void *priv, struct receive_sa *sa)
204 {
205 	struct hostapd_data *hapd = priv;
206 
207 	if (!hapd->driver->disable_receive_sa)
208 		return -1;
209 	return hapd->driver->disable_receive_sa(hapd->drv_priv, sa);
210 }
211 
212 
213 static int
214 hapd_create_transmit_sc(void *priv, struct transmit_sc *sc,
215 			enum confidentiality_offset co)
216 {
217 	struct hostapd_data *hapd = priv;
218 
219 	if (!hapd->driver->create_transmit_sc)
220 		return -1;
221 	return hapd->driver->create_transmit_sc(hapd->drv_priv, sc,
222 						conf_offset_val(co));
223 }
224 
225 
226 static int hapd_delete_transmit_sc(void *priv, struct transmit_sc *sc)
227 {
228 	struct hostapd_data *hapd = priv;
229 
230 	if (!hapd->driver->delete_transmit_sc)
231 		return -1;
232 	return hapd->driver->delete_transmit_sc(hapd->drv_priv, sc);
233 }
234 
235 
236 static int hapd_create_transmit_sa(void *priv, struct transmit_sa *sa)
237 {
238 	struct hostapd_data *hapd = priv;
239 
240 	if (!hapd->driver->create_transmit_sa)
241 		return -1;
242 	return hapd->driver->create_transmit_sa(hapd->drv_priv, sa);
243 }
244 
245 
246 static int hapd_delete_transmit_sa(void *priv, struct transmit_sa *sa)
247 {
248 	struct hostapd_data *hapd = priv;
249 
250 	if (!hapd->driver->delete_transmit_sa)
251 		return -1;
252 	return hapd->driver->delete_transmit_sa(hapd->drv_priv, sa);
253 }
254 
255 
256 static int hapd_enable_transmit_sa(void *priv, struct transmit_sa *sa)
257 {
258 	struct hostapd_data *hapd = priv;
259 
260 	if (!hapd->driver->enable_transmit_sa)
261 		return -1;
262 	return hapd->driver->enable_transmit_sa(hapd->drv_priv, sa);
263 }
264 
265 
266 static int hapd_disable_transmit_sa(void *priv, struct transmit_sa *sa)
267 {
268 	struct hostapd_data *hapd = priv;
269 
270 	if (!hapd->driver->disable_transmit_sa)
271 		return -1;
272 	return hapd->driver->disable_transmit_sa(hapd->drv_priv, sa);
273 }
274 
275 
276 int ieee802_1x_alloc_kay_sm_hapd(struct hostapd_data *hapd,
277 				 struct sta_info *sta)
278 {
279 	struct ieee802_1x_kay_ctx *kay_ctx;
280 	struct ieee802_1x_kay *res = NULL;
281 	enum macsec_policy policy;
282 
283 	ieee802_1x_dealloc_kay_sm_hapd(hapd);
284 
285 	if (!hapd->conf || hapd->conf->macsec_policy == 0)
286 		return 0;
287 
288 	if (hapd->conf->macsec_policy == 1) {
289 		if (hapd->conf->macsec_integ_only == 1)
290 			policy = SHOULD_SECURE;
291 		else
292 			policy = SHOULD_ENCRYPT;
293 	} else {
294 		policy = DO_NOT_SECURE;
295 	}
296 
297 	wpa_printf(MSG_DEBUG, "%s: if_name=%s", __func__, hapd->conf->iface);
298 	kay_ctx = os_zalloc(sizeof(*kay_ctx));
299 	if (!kay_ctx)
300 		return -1;
301 
302 	kay_ctx->ctx = hapd;
303 
304 	kay_ctx->macsec_init = hapd_macsec_init;
305 	kay_ctx->macsec_deinit = hapd_macsec_deinit;
306 	kay_ctx->macsec_get_capability = hapd_macsec_get_capability;
307 	kay_ctx->enable_protect_frames = hapd_enable_protect_frames;
308 	kay_ctx->enable_encrypt = hapd_enable_encrypt;
309 	kay_ctx->set_replay_protect = hapd_set_replay_protect;
310 	kay_ctx->set_current_cipher_suite = hapd_set_current_cipher_suite;
311 	kay_ctx->enable_controlled_port = hapd_enable_controlled_port;
312 	kay_ctx->get_receive_lowest_pn = hapd_get_receive_lowest_pn;
313 	kay_ctx->get_transmit_next_pn = hapd_get_transmit_next_pn;
314 	kay_ctx->set_transmit_next_pn = hapd_set_transmit_next_pn;
315 	kay_ctx->create_receive_sc = hapd_create_receive_sc;
316 	kay_ctx->delete_receive_sc = hapd_delete_receive_sc;
317 	kay_ctx->create_receive_sa = hapd_create_receive_sa;
318 	kay_ctx->delete_receive_sa = hapd_delete_receive_sa;
319 	kay_ctx->enable_receive_sa = hapd_enable_receive_sa;
320 	kay_ctx->disable_receive_sa = hapd_disable_receive_sa;
321 	kay_ctx->create_transmit_sc = hapd_create_transmit_sc;
322 	kay_ctx->delete_transmit_sc = hapd_delete_transmit_sc;
323 	kay_ctx->create_transmit_sa = hapd_create_transmit_sa;
324 	kay_ctx->delete_transmit_sa = hapd_delete_transmit_sa;
325 	kay_ctx->enable_transmit_sa = hapd_enable_transmit_sa;
326 	kay_ctx->disable_transmit_sa = hapd_disable_transmit_sa;
327 
328 	res = ieee802_1x_kay_init(kay_ctx, policy,
329 				  hapd->conf->macsec_replay_protect,
330 				  hapd->conf->macsec_replay_window,
331 				  hapd->conf->macsec_port,
332 				  hapd->conf->mka_priority, hapd->conf->iface,
333 				  hapd->own_addr);
334 	/* ieee802_1x_kay_init() frees kay_ctx on failure */
335 	if (!res)
336 		return -1;
337 
338 	hapd->kay = res;
339 
340 	return 0;
341 }
342 
343 
344 void ieee802_1x_dealloc_kay_sm_hapd(struct hostapd_data *hapd)
345 {
346 	if (!hapd->kay)
347 		return;
348 
349 	ieee802_1x_kay_deinit(hapd->kay);
350 	hapd->kay = NULL;
351 }
352 
353 
354 static int ieee802_1x_auth_get_session_id(struct hostapd_data *hapd,
355 					  struct sta_info *sta, u8 *sid,
356 					  size_t *len)
357 {
358 	const u8 *session_id;
359 	size_t id_len, need_len;
360 
361 	session_id = ieee802_1x_get_session_id(sta->eapol_sm, &id_len);
362 	if (!session_id) {
363 		wpa_printf(MSG_DEBUG,
364 			   "MACsec: Failed to get SessionID from EAPOL state machines");
365 		return -1;
366 	}
367 
368 	need_len = 1 + 2 * 32 /* random size */;
369 	if (need_len > id_len) {
370 		wpa_printf(MSG_DEBUG, "EAP Session-Id not long enough");
371 		return -1;
372 	}
373 
374 	os_memcpy(sid, session_id, need_len);
375 	*len = need_len;
376 
377 	return 0;
378 }
379 
380 
381 static int ieee802_1x_auth_get_msk(struct hostapd_data *hapd,
382 				   struct sta_info *sta, u8 *msk, size_t *len)
383 {
384 	const u8 *key;
385 	size_t keylen;
386 
387 	if (!sta->eapol_sm)
388 		return -1;
389 
390 	key = ieee802_1x_get_key(sta->eapol_sm, &keylen);
391 	if (key == NULL) {
392 		wpa_printf(MSG_DEBUG,
393 			   "MACsec: Failed to get MSK from EAPOL state machines");
394 		return -1;
395 	}
396 	wpa_printf(MSG_DEBUG, "MACsec: Successfully fetched key (len=%lu)",
397 		   (unsigned long) keylen);
398 	wpa_hexdump_key(MSG_DEBUG, "MSK: ", key, keylen);
399 
400 	if (keylen > *len)
401 		keylen = *len;
402 	os_memcpy(msk, key, keylen);
403 	*len = keylen;
404 
405 	return 0;
406 }
407 
408 
409 void * ieee802_1x_notify_create_actor_hapd(struct hostapd_data *hapd,
410 					   struct sta_info *sta)
411 {
412 	u8 *sid;
413 	size_t sid_len = 128;
414 	struct mka_key_name *ckn;
415 	struct mka_key *cak;
416 	struct mka_key *msk;
417 	void *res = NULL;
418 
419 	if (!hapd->kay || hapd->kay->policy == DO_NOT_SECURE)
420 		return NULL;
421 
422 	wpa_printf(MSG_DEBUG,
423 		   "IEEE 802.1X: External notification - Create MKA for "
424 		   MACSTR, MAC2STR(sta->addr));
425 
426 	msk = os_zalloc(sizeof(*msk));
427 	sid = os_zalloc(sid_len);
428 	ckn = os_zalloc(sizeof(*ckn));
429 	cak = os_zalloc(sizeof(*cak));
430 	if (!msk || !sid || !ckn || !cak)
431 		goto fail;
432 
433 	msk->len = DEFAULT_KEY_LEN;
434 	if (ieee802_1x_auth_get_msk(hapd, sta, msk->key, &msk->len)) {
435 		wpa_printf(MSG_ERROR, "IEEE 802.1X: Could not get MSK");
436 		goto fail;
437 	}
438 
439 	if (ieee802_1x_auth_get_session_id(hapd, sta, sid, &sid_len))
440 	{
441 		wpa_printf(MSG_ERROR,
442 			   "IEEE 802.1X: Could not get EAP Session Id");
443 		goto fail;
444 	}
445 
446 	wpa_hexdump(MSG_DEBUG, "own_addr", hapd->own_addr, ETH_ALEN);
447 	wpa_hexdump(MSG_DEBUG, "sta_addr", sta->addr, ETH_ALEN);
448 
449 	/* Derive CAK from MSK */
450 	cak->len = DEFAULT_KEY_LEN;
451 	if (ieee802_1x_cak_aes_cmac(msk->key, msk->len, hapd->own_addr,
452 				    sta->addr, cak->key, cak->len)) {
453 		wpa_printf(MSG_ERROR, "IEEE 802.1X: Deriving CAK failed");
454 		goto fail;
455 	}
456 	wpa_hexdump_key(MSG_DEBUG, "Derived CAK", cak->key, cak->len);
457 
458 	/* Derive CKN from MSK */
459 	ckn->len = DEFAULT_CKN_LEN;
460 	if (ieee802_1x_ckn_aes_cmac(msk->key, msk->len, hapd->own_addr,
461 				    sta->addr, sid, sid_len, ckn->name)) {
462 		wpa_printf(MSG_ERROR, "IEEE 802.1X: Deriving CKN failed");
463 		goto fail;
464 	}
465 	wpa_hexdump(MSG_DEBUG, "Derived CKN", ckn->name, ckn->len);
466 
467 	res = ieee802_1x_kay_create_mka(hapd->kay, ckn, cak, 0, EAP_EXCHANGE,
468 					true);
469 
470 fail:
471 	bin_clear_free(msk, sizeof(*msk));
472 	os_free(sid);
473 	os_free(ckn);
474 	bin_clear_free(cak, sizeof(*cak));
475 
476 	return res;
477 }
478 
479 
480 void * ieee802_1x_create_preshared_mka_hapd(struct hostapd_data *hapd,
481 					    struct sta_info *sta)
482 {
483 	struct mka_key *cak;
484 	struct mka_key_name *ckn;
485 	void *res = NULL;
486 
487 	if ((hapd->conf->mka_psk_set & MKA_PSK_SET) != MKA_PSK_SET)
488 		goto end;
489 
490 	ckn = os_zalloc(sizeof(*ckn));
491 	if (!ckn)
492 		goto end;
493 
494 	cak = os_zalloc(sizeof(*cak));
495 	if (!cak)
496 		goto free_ckn;
497 
498 	if (ieee802_1x_alloc_kay_sm_hapd(hapd, sta) < 0 || !hapd->kay)
499 		goto free_cak;
500 
501 	if (hapd->kay->policy == DO_NOT_SECURE)
502 		goto dealloc;
503 
504 	cak->len = hapd->conf->mka_cak_len;
505 	os_memcpy(cak->key, hapd->conf->mka_cak, cak->len);
506 
507 	ckn->len = hapd->conf->mka_ckn_len;;
508 	os_memcpy(ckn->name, hapd->conf->mka_ckn, ckn->len);
509 
510 	res = ieee802_1x_kay_create_mka(hapd->kay, ckn, cak, 0, PSK, true);
511 	if (res)
512 		goto free_cak;
513 
514 dealloc:
515 	/* Failed to create MKA */
516 	ieee802_1x_dealloc_kay_sm_hapd(hapd);
517 free_cak:
518 	os_free(cak);
519 free_ckn:
520 	os_free(ckn);
521 end:
522 	return res;
523 }
524