1 /*
2  * Wi-Fi Protected Setup - Enrollee
3  * Copyright (c) 2008, Jouni Malinen <j@w1.fi>
4  *
5  * This software may be distributed under the terms of the BSD license.
6  * See README for more details.
7  */
8 
9 #include "includes.h"
10 
11 #include "common.h"
12 #include "crypto/crypto.h"
13 #include "crypto/sha256.h"
14 #include "crypto/random.h"
15 #include "wps_i.h"
16 #include "wps_dev_attr.h"
17 
18 
wps_build_wps_state(struct wps_data * wps,struct wpabuf * msg)19 static int wps_build_wps_state(struct wps_data *wps, struct wpabuf *msg)
20 {
21 	u8 state;
22 	if (wps->wps->ap)
23 		state = wps->wps->wps_state;
24 	else
25 		state = WPS_STATE_NOT_CONFIGURED;
26 	wpa_printf(MSG_DEBUG, "WPS:  * Wi-Fi Protected Setup State (%d)",
27 		   state);
28 	wpabuf_put_be16(msg, ATTR_WPS_STATE);
29 	wpabuf_put_be16(msg, 1);
30 	wpabuf_put_u8(msg, state);
31 	return 0;
32 }
33 
34 
wps_build_e_hash(struct wps_data * wps,struct wpabuf * msg)35 static int wps_build_e_hash(struct wps_data *wps, struct wpabuf *msg)
36 {
37 	u8 *hash;
38 	const u8 *addr[4];
39 	size_t len[4];
40 
41 	if (random_get_bytes(wps->snonce, 2 * WPS_SECRET_NONCE_LEN) < 0)
42 		return -1;
43 	wpa_hexdump(MSG_DEBUG, "WPS: E-S1", wps->snonce, WPS_SECRET_NONCE_LEN);
44 	wpa_hexdump(MSG_DEBUG, "WPS: E-S2",
45 		    wps->snonce + WPS_SECRET_NONCE_LEN, WPS_SECRET_NONCE_LEN);
46 
47 	if (wps->dh_pubkey_e == NULL || wps->dh_pubkey_r == NULL) {
48 		wpa_printf(MSG_DEBUG, "WPS: DH public keys not available for "
49 			   "E-Hash derivation");
50 		return -1;
51 	}
52 
53 	wpa_printf(MSG_DEBUG, "WPS:  * E-Hash1");
54 	wpabuf_put_be16(msg, ATTR_E_HASH1);
55 	wpabuf_put_be16(msg, SHA256_MAC_LEN);
56 	hash = wpabuf_put(msg, SHA256_MAC_LEN);
57 	/* E-Hash1 = HMAC_AuthKey(E-S1 || PSK1 || PK_E || PK_R) */
58 	addr[0] = wps->snonce;
59 	len[0] = WPS_SECRET_NONCE_LEN;
60 	addr[1] = wps->psk1;
61 	len[1] = WPS_PSK_LEN;
62 	addr[2] = wpabuf_head(wps->dh_pubkey_e);
63 	len[2] = wpabuf_len(wps->dh_pubkey_e);
64 	addr[3] = wpabuf_head(wps->dh_pubkey_r);
65 	len[3] = wpabuf_len(wps->dh_pubkey_r);
66 	hmac_sha256_vector(wps->authkey, WPS_AUTHKEY_LEN, 4, addr, len, hash);
67 	wpa_hexdump(MSG_DEBUG, "WPS: E-Hash1", hash, SHA256_MAC_LEN);
68 
69 	wpa_printf(MSG_DEBUG, "WPS:  * E-Hash2");
70 	wpabuf_put_be16(msg, ATTR_E_HASH2);
71 	wpabuf_put_be16(msg, SHA256_MAC_LEN);
72 	hash = wpabuf_put(msg, SHA256_MAC_LEN);
73 	/* E-Hash2 = HMAC_AuthKey(E-S2 || PSK2 || PK_E || PK_R) */
74 	addr[0] = wps->snonce + WPS_SECRET_NONCE_LEN;
75 	addr[1] = wps->psk2;
76 	hmac_sha256_vector(wps->authkey, WPS_AUTHKEY_LEN, 4, addr, len, hash);
77 	wpa_hexdump(MSG_DEBUG, "WPS: E-Hash2", hash, SHA256_MAC_LEN);
78 
79 	return 0;
80 }
81 
82 
wps_build_e_snonce1(struct wps_data * wps,struct wpabuf * msg)83 static int wps_build_e_snonce1(struct wps_data *wps, struct wpabuf *msg)
84 {
85 	wpa_printf(MSG_DEBUG, "WPS:  * E-SNonce1");
86 	wpabuf_put_be16(msg, ATTR_E_SNONCE1);
87 	wpabuf_put_be16(msg, WPS_SECRET_NONCE_LEN);
88 	wpabuf_put_data(msg, wps->snonce, WPS_SECRET_NONCE_LEN);
89 	return 0;
90 }
91 
92 
wps_build_e_snonce2(struct wps_data * wps,struct wpabuf * msg)93 static int wps_build_e_snonce2(struct wps_data *wps, struct wpabuf *msg)
94 {
95 	wpa_printf(MSG_DEBUG, "WPS:  * E-SNonce2");
96 	wpabuf_put_be16(msg, ATTR_E_SNONCE2);
97 	wpabuf_put_be16(msg, WPS_SECRET_NONCE_LEN);
98 	wpabuf_put_data(msg, wps->snonce + WPS_SECRET_NONCE_LEN,
99 			WPS_SECRET_NONCE_LEN);
100 	return 0;
101 }
102 
103 
wps_build_m1(struct wps_data * wps)104 static struct wpabuf * wps_build_m1(struct wps_data *wps)
105 {
106 	struct wpabuf *msg;
107 	u16 config_methods;
108 
109 	if (random_get_bytes(wps->nonce_e, WPS_NONCE_LEN) < 0)
110 		return NULL;
111 	wpa_hexdump(MSG_DEBUG, "WPS: Enrollee Nonce",
112 		    wps->nonce_e, WPS_NONCE_LEN);
113 
114 	wpa_printf(MSG_DEBUG, "WPS: Building Message M1");
115 	msg = wpabuf_alloc(1000);
116 	if (msg == NULL)
117 		return NULL;
118 
119 	config_methods = wps->wps->config_methods;
120 	if (wps->wps->ap && !wps->pbc_in_m1 &&
121 	    (wps->dev_password_len != 0 ||
122 	     (config_methods & WPS_CONFIG_DISPLAY))) {
123 		/*
124 		 * These are the methods that the AP supports as an Enrollee
125 		 * for adding external Registrars, so remove PushButton.
126 		 *
127 		 * As a workaround for Windows 7 mechanism for probing WPS
128 		 * capabilities from M1, leave PushButton option if no PIN
129 		 * method is available or if WPS configuration enables PBC
130 		 * workaround.
131 		 */
132 		config_methods &= ~WPS_CONFIG_PUSHBUTTON;
133 		config_methods &= ~(WPS_CONFIG_VIRT_PUSHBUTTON |
134 				    WPS_CONFIG_PHY_PUSHBUTTON);
135 	}
136 
137 	if (wps_build_version(msg) ||
138 	    wps_build_msg_type(msg, WPS_M1) ||
139 	    wps_build_uuid_e(msg, wps->uuid_e) ||
140 	    wps_build_mac_addr(msg, wps->mac_addr_e) ||
141 	    wps_build_enrollee_nonce(wps, msg) ||
142 	    wps_build_public_key(wps, msg) ||
143 	    wps_build_auth_type_flags(wps, msg) ||
144 	    wps_build_encr_type_flags(wps, msg) ||
145 	    wps_build_conn_type_flags(wps, msg) ||
146 	    wps_build_config_methods(msg, config_methods) ||
147 	    wps_build_wps_state(wps, msg) ||
148 	    wps_build_device_attrs(&wps->wps->dev, msg) ||
149 	    wps_build_rf_bands(&wps->wps->dev, msg,
150 			       wps->wps->rf_band_cb(wps->wps->cb_ctx)) ||
151 	    wps_build_assoc_state(wps, msg) ||
152 	    wps_build_dev_password_id(msg, wps->dev_pw_id) ||
153 	    wps_build_config_error(msg, WPS_CFG_NO_ERROR) ||
154 	    wps_build_os_version(&wps->wps->dev, msg) ||
155 	    wps_build_wfa_ext(msg, 0, NULL, 0) ||
156 	    wps_build_vendor_ext_m1(&wps->wps->dev, msg)) {
157 		wpabuf_free(msg);
158 		return NULL;
159 	}
160 
161 	wps->state = RECV_M2;
162 	return msg;
163 }
164 
165 
wps_build_m3(struct wps_data * wps)166 static struct wpabuf * wps_build_m3(struct wps_data *wps)
167 {
168 	struct wpabuf *msg;
169 
170 	wpa_printf(MSG_DEBUG, "WPS: Building Message M3");
171 
172 	if (wps->dev_password == NULL) {
173 		wpa_printf(MSG_DEBUG, "WPS: No Device Password available");
174 		return NULL;
175 	}
176 	wps_derive_psk(wps, wps->dev_password, wps->dev_password_len);
177 
178 	if (wps->wps->ap && random_pool_ready() != 1) {
179 		wpa_printf(MSG_INFO,
180 			   "WPS: Not enough entropy in random pool to proceed - do not allow AP PIN to be used");
181 		return NULL;
182 	}
183 
184 	msg = wpabuf_alloc(1000);
185 	if (msg == NULL)
186 		return NULL;
187 
188 	if (wps_build_version(msg) ||
189 	    wps_build_msg_type(msg, WPS_M3) ||
190 	    wps_build_registrar_nonce(wps, msg) ||
191 	    wps_build_e_hash(wps, msg) ||
192 	    wps_build_wfa_ext(msg, 0, NULL, 0) ||
193 	    wps_build_authenticator(wps, msg)) {
194 		wpabuf_free(msg);
195 		return NULL;
196 	}
197 
198 	wps->state = RECV_M4;
199 	return msg;
200 }
201 
202 
wps_build_m5(struct wps_data * wps)203 static struct wpabuf * wps_build_m5(struct wps_data *wps)
204 {
205 	struct wpabuf *msg, *plain;
206 
207 	wpa_printf(MSG_DEBUG, "WPS: Building Message M5");
208 
209 	plain = wpabuf_alloc(200);
210 	if (plain == NULL)
211 		return NULL;
212 
213 	msg = wpabuf_alloc(1000);
214 	if (msg == NULL) {
215 		wpabuf_free(plain);
216 		return NULL;
217 	}
218 
219 	if (wps_build_version(msg) ||
220 	    wps_build_msg_type(msg, WPS_M5) ||
221 	    wps_build_registrar_nonce(wps, msg) ||
222 	    wps_build_e_snonce1(wps, plain) ||
223 	    wps_build_key_wrap_auth(wps, plain) ||
224 	    wps_build_encr_settings(wps, msg, plain) ||
225 	    wps_build_wfa_ext(msg, 0, NULL, 0) ||
226 	    wps_build_authenticator(wps, msg)) {
227 		wpabuf_free(plain);
228 		wpabuf_free(msg);
229 		return NULL;
230 	}
231 	wpabuf_free(plain);
232 
233 	wps->state = RECV_M6;
234 	return msg;
235 }
236 
237 
wps_build_cred_ssid(struct wps_data * wps,struct wpabuf * msg)238 static int wps_build_cred_ssid(struct wps_data *wps, struct wpabuf *msg)
239 {
240 	wpa_printf(MSG_DEBUG, "WPS:  * SSID");
241 	wpabuf_put_be16(msg, ATTR_SSID);
242 	wpabuf_put_be16(msg, wps->wps->ssid_len);
243 	wpabuf_put_data(msg, wps->wps->ssid, wps->wps->ssid_len);
244 	return 0;
245 }
246 
247 
wps_build_cred_auth_type(struct wps_data * wps,struct wpabuf * msg)248 static int wps_build_cred_auth_type(struct wps_data *wps, struct wpabuf *msg)
249 {
250 	u16 auth_type = wps->wps->ap_auth_type;
251 
252 	/*
253 	 * Work around issues with Windows 7 WPS implementation not liking
254 	 * multiple Authentication Type bits in M7 AP Settings attribute by
255 	 * showing only the most secure option from current configuration.
256 	 */
257 	if (auth_type & WPS_AUTH_WPA2PSK)
258 		auth_type = WPS_AUTH_WPA2PSK;
259 	else if (auth_type & WPS_AUTH_WPAPSK)
260 		auth_type = WPS_AUTH_WPAPSK;
261 	else if (auth_type & WPS_AUTH_OPEN)
262 		auth_type = WPS_AUTH_OPEN;
263 
264 	wpa_printf(MSG_DEBUG, "WPS:  * Authentication Type (0x%x)", auth_type);
265 	wpabuf_put_be16(msg, ATTR_AUTH_TYPE);
266 	wpabuf_put_be16(msg, 2);
267 	wpabuf_put_be16(msg, auth_type);
268 	return 0;
269 }
270 
271 
wps_build_cred_encr_type(struct wps_data * wps,struct wpabuf * msg)272 static int wps_build_cred_encr_type(struct wps_data *wps, struct wpabuf *msg)
273 {
274 	u16 encr_type = wps->wps->ap_encr_type;
275 
276 	/*
277 	 * Work around issues with Windows 7 WPS implementation not liking
278 	 * multiple Encryption Type bits in M7 AP Settings attribute by
279 	 * showing only the most secure option from current configuration.
280 	 */
281 	if (wps->wps->ap_auth_type & (WPS_AUTH_WPA2PSK | WPS_AUTH_WPAPSK)) {
282 		if (encr_type & WPS_ENCR_AES)
283 			encr_type = WPS_ENCR_AES;
284 		else if (encr_type & WPS_ENCR_TKIP)
285 			encr_type = WPS_ENCR_TKIP;
286 	}
287 
288 	wpa_printf(MSG_DEBUG, "WPS:  * Encryption Type (0x%x)", encr_type);
289 	wpabuf_put_be16(msg, ATTR_ENCR_TYPE);
290 	wpabuf_put_be16(msg, 2);
291 	wpabuf_put_be16(msg, encr_type);
292 	return 0;
293 }
294 
295 
wps_build_cred_network_key(struct wps_data * wps,struct wpabuf * msg)296 static int wps_build_cred_network_key(struct wps_data *wps, struct wpabuf *msg)
297 {
298 	if ((wps->wps->ap_auth_type & (WPS_AUTH_WPAPSK | WPS_AUTH_WPA2PSK)) &&
299 	    wps->wps->network_key_len == 0) {
300 		char hex[65];
301 		u8 psk[32];
302 		/* Generate a random per-device PSK */
303 		if (random_pool_ready() != 1 ||
304 		    random_get_bytes(psk, sizeof(psk)) < 0) {
305 			wpa_printf(MSG_INFO,
306 				   "WPS: Could not generate random PSK");
307 			return -1;
308 		}
309 		wpa_hexdump_key(MSG_DEBUG, "WPS: Generated per-device PSK",
310 				psk, sizeof(psk));
311 		wpa_printf(MSG_DEBUG, "WPS:  * Network Key (len=%u)",
312 			   (unsigned int) wps->new_psk_len * 2);
313 		wpa_snprintf_hex(hex, sizeof(hex), psk, sizeof(psk));
314 		wpabuf_put_be16(msg, ATTR_NETWORK_KEY);
315 		wpabuf_put_be16(msg, sizeof(psk) * 2);
316 		wpabuf_put_data(msg, hex, sizeof(psk) * 2);
317 		if (wps->wps->registrar) {
318 			wps_cb_new_psk(wps->wps->registrar,
319 				       wps->peer_dev.mac_addr,
320 				       wps->p2p_dev_addr, psk, sizeof(psk));
321 		}
322 		return 0;
323 	}
324 
325 	wpa_printf(MSG_DEBUG, "WPS:  * Network Key (len=%u)",
326 		   (unsigned int) wps->wps->network_key_len);
327 	wpabuf_put_be16(msg, ATTR_NETWORK_KEY);
328 	wpabuf_put_be16(msg, wps->wps->network_key_len);
329 	wpabuf_put_data(msg, wps->wps->network_key, wps->wps->network_key_len);
330 	return 0;
331 }
332 
333 
wps_build_cred_mac_addr(struct wps_data * wps,struct wpabuf * msg)334 static int wps_build_cred_mac_addr(struct wps_data *wps, struct wpabuf *msg)
335 {
336 	wpa_printf(MSG_DEBUG, "WPS:  * MAC Address (AP BSSID)");
337 	wpabuf_put_be16(msg, ATTR_MAC_ADDR);
338 	wpabuf_put_be16(msg, ETH_ALEN);
339 	wpabuf_put_data(msg, wps->wps->dev.mac_addr, ETH_ALEN);
340 	return 0;
341 }
342 
343 
wps_build_ap_settings(struct wps_data * wps,struct wpabuf * plain)344 static int wps_build_ap_settings(struct wps_data *wps, struct wpabuf *plain)
345 {
346 	const u8 *start, *end;
347 	int ret;
348 
349 	if (wps->wps->ap_settings) {
350 		wpa_printf(MSG_DEBUG, "WPS:  * AP Settings (pre-configured)");
351 		wpabuf_put_data(plain, wps->wps->ap_settings,
352 				wps->wps->ap_settings_len);
353 		return 0;
354 	}
355 
356 	wpa_printf(MSG_DEBUG, "WPS:  * AP Settings based on current configuration");
357 	start = wpabuf_put(plain, 0);
358 	ret = wps_build_cred_ssid(wps, plain) ||
359 		wps_build_cred_mac_addr(wps, plain) ||
360 		wps_build_cred_auth_type(wps, plain) ||
361 		wps_build_cred_encr_type(wps, plain) ||
362 		wps_build_cred_network_key(wps, plain);
363 	end = wpabuf_put(plain, 0);
364 
365 	wpa_hexdump_key(MSG_DEBUG, "WPS: Plaintext AP Settings",
366 			start, end - start);
367 
368 	return ret;
369 }
370 
371 
wps_build_m7(struct wps_data * wps)372 static struct wpabuf * wps_build_m7(struct wps_data *wps)
373 {
374 	struct wpabuf *msg, *plain;
375 
376 	wpa_printf(MSG_DEBUG, "WPS: Building Message M7");
377 
378 	plain = wpabuf_alloc(500 + wps->wps->ap_settings_len);
379 	if (plain == NULL)
380 		return NULL;
381 
382 	msg = wpabuf_alloc(1000 + wps->wps->ap_settings_len);
383 	if (msg == NULL) {
384 		wpabuf_free(plain);
385 		return NULL;
386 	}
387 
388 	if (wps_build_version(msg) ||
389 	    wps_build_msg_type(msg, WPS_M7) ||
390 	    wps_build_registrar_nonce(wps, msg) ||
391 	    wps_build_e_snonce2(wps, plain) ||
392 	    (wps->wps->ap && wps_build_ap_settings(wps, plain)) ||
393 	    wps_build_key_wrap_auth(wps, plain) ||
394 	    wps_build_encr_settings(wps, msg, plain) ||
395 	    wps_build_wfa_ext(msg, 0, NULL, 0) ||
396 	    wps_build_authenticator(wps, msg)) {
397 		wpabuf_free(plain);
398 		wpabuf_free(msg);
399 		return NULL;
400 	}
401 	wpabuf_free(plain);
402 
403 	if (wps->wps->ap && wps->wps->registrar) {
404 		/*
405 		 * If the Registrar is only learning our current configuration,
406 		 * it may not continue protocol run to successful completion.
407 		 * Store information here to make sure it remains available.
408 		 */
409 		wps_device_store(wps->wps->registrar, &wps->peer_dev,
410 				 wps->uuid_r);
411 	}
412 
413 	wps->state = RECV_M8;
414 	return msg;
415 }
416 
417 
wps_build_wsc_done(struct wps_data * wps)418 static struct wpabuf * wps_build_wsc_done(struct wps_data *wps)
419 {
420 	struct wpabuf *msg;
421 
422 	wpa_printf(MSG_DEBUG, "WPS: Building Message WSC_Done");
423 
424 	msg = wpabuf_alloc(1000);
425 	if (msg == NULL)
426 		return NULL;
427 
428 	if (wps_build_version(msg) ||
429 	    wps_build_msg_type(msg, WPS_WSC_DONE) ||
430 	    wps_build_enrollee_nonce(wps, msg) ||
431 	    wps_build_registrar_nonce(wps, msg) ||
432 	    wps_build_wfa_ext(msg, 0, NULL, 0)) {
433 		wpabuf_free(msg);
434 		return NULL;
435 	}
436 
437 	if (wps->wps->ap)
438 		wps->state = RECV_ACK;
439 	else {
440 		wps_success_event(wps->wps, wps->peer_dev.mac_addr);
441 		wps->state = WPS_FINISHED;
442 	}
443 	return msg;
444 }
445 
446 
wps_enrollee_get_msg(struct wps_data * wps,enum wsc_op_code * op_code)447 struct wpabuf * wps_enrollee_get_msg(struct wps_data *wps,
448 				     enum wsc_op_code *op_code)
449 {
450 	struct wpabuf *msg;
451 
452 	switch (wps->state) {
453 	case SEND_M1:
454 		msg = wps_build_m1(wps);
455 		*op_code = WSC_MSG;
456 		break;
457 	case SEND_M3:
458 		msg = wps_build_m3(wps);
459 		*op_code = WSC_MSG;
460 		break;
461 	case SEND_M5:
462 		msg = wps_build_m5(wps);
463 		*op_code = WSC_MSG;
464 		break;
465 	case SEND_M7:
466 		msg = wps_build_m7(wps);
467 		*op_code = WSC_MSG;
468 		break;
469 	case RECEIVED_M2D:
470 		if (wps->wps->ap) {
471 			msg = wps_build_wsc_nack(wps);
472 			*op_code = WSC_NACK;
473 			break;
474 		}
475 		msg = wps_build_wsc_ack(wps);
476 		*op_code = WSC_ACK;
477 		if (msg) {
478 			/* Another M2/M2D may be received */
479 			wps->state = RECV_M2;
480 		}
481 		break;
482 	case SEND_WSC_NACK:
483 		msg = wps_build_wsc_nack(wps);
484 		*op_code = WSC_NACK;
485 		break;
486 	case WPS_MSG_DONE:
487 		msg = wps_build_wsc_done(wps);
488 		*op_code = WSC_Done;
489 		break;
490 	default:
491 		wpa_printf(MSG_DEBUG, "WPS: Unsupported state %d for building "
492 			   "a message", wps->state);
493 		msg = NULL;
494 		break;
495 	}
496 
497 	if (*op_code == WSC_MSG && msg) {
498 		/* Save a copy of the last message for Authenticator derivation
499 		 */
500 		wpabuf_free(wps->last_msg);
501 		wps->last_msg = wpabuf_dup(msg);
502 	}
503 
504 	return msg;
505 }
506 
507 
wps_process_registrar_nonce(struct wps_data * wps,const u8 * r_nonce)508 static int wps_process_registrar_nonce(struct wps_data *wps, const u8 *r_nonce)
509 {
510 	if (r_nonce == NULL) {
511 		wpa_printf(MSG_DEBUG, "WPS: No Registrar Nonce received");
512 		return -1;
513 	}
514 
515 	os_memcpy(wps->nonce_r, r_nonce, WPS_NONCE_LEN);
516 	wpa_hexdump(MSG_DEBUG, "WPS: Registrar Nonce",
517 		    wps->nonce_r, WPS_NONCE_LEN);
518 
519 	return 0;
520 }
521 
522 
wps_process_enrollee_nonce(struct wps_data * wps,const u8 * e_nonce)523 static int wps_process_enrollee_nonce(struct wps_data *wps, const u8 *e_nonce)
524 {
525 	if (e_nonce == NULL) {
526 		wpa_printf(MSG_DEBUG, "WPS: No Enrollee Nonce received");
527 		return -1;
528 	}
529 
530 	if (os_memcmp(wps->nonce_e, e_nonce, WPS_NONCE_LEN) != 0) {
531 		wpa_printf(MSG_DEBUG, "WPS: Invalid Enrollee Nonce received");
532 		return -1;
533 	}
534 
535 	return 0;
536 }
537 
538 
wps_process_uuid_r(struct wps_data * wps,const u8 * uuid_r)539 static int wps_process_uuid_r(struct wps_data *wps, const u8 *uuid_r)
540 {
541 	if (uuid_r == NULL) {
542 		wpa_printf(MSG_DEBUG, "WPS: No UUID-R received");
543 		return -1;
544 	}
545 
546 	os_memcpy(wps->uuid_r, uuid_r, WPS_UUID_LEN);
547 	wpa_hexdump(MSG_DEBUG, "WPS: UUID-R", wps->uuid_r, WPS_UUID_LEN);
548 
549 	return 0;
550 }
551 
552 
wps_process_pubkey(struct wps_data * wps,const u8 * pk,size_t pk_len)553 static int wps_process_pubkey(struct wps_data *wps, const u8 *pk,
554 			      size_t pk_len)
555 {
556 	if (pk == NULL || pk_len == 0) {
557 		wpa_printf(MSG_DEBUG, "WPS: No Public Key received");
558 		return -1;
559 	}
560 
561 	if (wps->peer_pubkey_hash_set) {
562 		u8 hash[WPS_HASH_LEN];
563 		sha256_vector(1, &pk, &pk_len, hash);
564 		if (os_memcmp_const(hash, wps->peer_pubkey_hash,
565 				    WPS_OOB_PUBKEY_HASH_LEN) != 0) {
566 			wpa_printf(MSG_ERROR, "WPS: Public Key hash mismatch");
567 			wpa_hexdump(MSG_DEBUG, "WPS: Received public key",
568 				    pk, pk_len);
569 			wpa_hexdump(MSG_DEBUG, "WPS: Calculated public key "
570 				    "hash", hash, WPS_OOB_PUBKEY_HASH_LEN);
571 			wpa_hexdump(MSG_DEBUG, "WPS: Expected public key hash",
572 				    wps->peer_pubkey_hash,
573 				    WPS_OOB_PUBKEY_HASH_LEN);
574 			wps->config_error = WPS_CFG_PUBLIC_KEY_HASH_MISMATCH;
575 			return -1;
576 		}
577 	}
578 
579 	wpabuf_free(wps->dh_pubkey_r);
580 	wps->dh_pubkey_r = wpabuf_alloc_copy(pk, pk_len);
581 	if (wps->dh_pubkey_r == NULL)
582 		return -1;
583 
584 	if (wps_derive_keys(wps) < 0)
585 		return -1;
586 
587 	return 0;
588 }
589 
590 
wps_process_r_hash1(struct wps_data * wps,const u8 * r_hash1)591 static int wps_process_r_hash1(struct wps_data *wps, const u8 *r_hash1)
592 {
593 	if (r_hash1 == NULL) {
594 		wpa_printf(MSG_DEBUG, "WPS: No R-Hash1 received");
595 		return -1;
596 	}
597 
598 	os_memcpy(wps->peer_hash1, r_hash1, WPS_HASH_LEN);
599 	wpa_hexdump(MSG_DEBUG, "WPS: R-Hash1", wps->peer_hash1, WPS_HASH_LEN);
600 
601 	return 0;
602 }
603 
604 
wps_process_r_hash2(struct wps_data * wps,const u8 * r_hash2)605 static int wps_process_r_hash2(struct wps_data *wps, const u8 *r_hash2)
606 {
607 	if (r_hash2 == NULL) {
608 		wpa_printf(MSG_DEBUG, "WPS: No R-Hash2 received");
609 		return -1;
610 	}
611 
612 	os_memcpy(wps->peer_hash2, r_hash2, WPS_HASH_LEN);
613 	wpa_hexdump(MSG_DEBUG, "WPS: R-Hash2", wps->peer_hash2, WPS_HASH_LEN);
614 
615 	return 0;
616 }
617 
618 
wps_process_r_snonce1(struct wps_data * wps,const u8 * r_snonce1)619 static int wps_process_r_snonce1(struct wps_data *wps, const u8 *r_snonce1)
620 {
621 	u8 hash[SHA256_MAC_LEN];
622 	const u8 *addr[4];
623 	size_t len[4];
624 
625 	if (r_snonce1 == NULL) {
626 		wpa_printf(MSG_DEBUG, "WPS: No R-SNonce1 received");
627 		return -1;
628 	}
629 
630 	wpa_hexdump_key(MSG_DEBUG, "WPS: R-SNonce1", r_snonce1,
631 			WPS_SECRET_NONCE_LEN);
632 
633 	/* R-Hash1 = HMAC_AuthKey(R-S1 || PSK1 || PK_E || PK_R) */
634 	addr[0] = r_snonce1;
635 	len[0] = WPS_SECRET_NONCE_LEN;
636 	addr[1] = wps->psk1;
637 	len[1] = WPS_PSK_LEN;
638 	addr[2] = wpabuf_head(wps->dh_pubkey_e);
639 	len[2] = wpabuf_len(wps->dh_pubkey_e);
640 	addr[3] = wpabuf_head(wps->dh_pubkey_r);
641 	len[3] = wpabuf_len(wps->dh_pubkey_r);
642 	hmac_sha256_vector(wps->authkey, WPS_AUTHKEY_LEN, 4, addr, len, hash);
643 
644 	if (os_memcmp_const(wps->peer_hash1, hash, WPS_HASH_LEN) != 0) {
645 		wpa_printf(MSG_DEBUG, "WPS: R-Hash1 derived from R-S1 does "
646 			   "not match with the pre-committed value");
647 		wps->config_error = WPS_CFG_DEV_PASSWORD_AUTH_FAILURE;
648 		wps_pwd_auth_fail_event(wps->wps, 1, 1, wps->peer_dev.mac_addr);
649 		return -1;
650 	}
651 
652 	wpa_printf(MSG_DEBUG, "WPS: Registrar proved knowledge of the first "
653 		   "half of the device password");
654 
655 	return 0;
656 }
657 
658 
wps_process_r_snonce2(struct wps_data * wps,const u8 * r_snonce2)659 static int wps_process_r_snonce2(struct wps_data *wps, const u8 *r_snonce2)
660 {
661 	u8 hash[SHA256_MAC_LEN];
662 	const u8 *addr[4];
663 	size_t len[4];
664 
665 	if (r_snonce2 == NULL) {
666 		wpa_printf(MSG_DEBUG, "WPS: No R-SNonce2 received");
667 		return -1;
668 	}
669 
670 	wpa_hexdump_key(MSG_DEBUG, "WPS: R-SNonce2", r_snonce2,
671 			WPS_SECRET_NONCE_LEN);
672 
673 	/* R-Hash2 = HMAC_AuthKey(R-S2 || PSK2 || PK_E || PK_R) */
674 	addr[0] = r_snonce2;
675 	len[0] = WPS_SECRET_NONCE_LEN;
676 	addr[1] = wps->psk2;
677 	len[1] = WPS_PSK_LEN;
678 	addr[2] = wpabuf_head(wps->dh_pubkey_e);
679 	len[2] = wpabuf_len(wps->dh_pubkey_e);
680 	addr[3] = wpabuf_head(wps->dh_pubkey_r);
681 	len[3] = wpabuf_len(wps->dh_pubkey_r);
682 	hmac_sha256_vector(wps->authkey, WPS_AUTHKEY_LEN, 4, addr, len, hash);
683 
684 	if (os_memcmp_const(wps->peer_hash2, hash, WPS_HASH_LEN) != 0) {
685 		wpa_printf(MSG_DEBUG, "WPS: R-Hash2 derived from R-S2 does "
686 			   "not match with the pre-committed value");
687 		wps->config_error = WPS_CFG_DEV_PASSWORD_AUTH_FAILURE;
688 		wps_pwd_auth_fail_event(wps->wps, 1, 2, wps->peer_dev.mac_addr);
689 		return -1;
690 	}
691 
692 	wpa_printf(MSG_DEBUG, "WPS: Registrar proved knowledge of the second "
693 		   "half of the device password");
694 
695 	return 0;
696 }
697 
698 
wps_process_cred_e(struct wps_data * wps,const u8 * cred,size_t cred_len,int wps2)699 static int wps_process_cred_e(struct wps_data *wps, const u8 *cred,
700 			      size_t cred_len, int wps2)
701 {
702 	struct wps_parse_attr attr;
703 	struct wpabuf msg;
704 	int ret = 0;
705 
706 	wpa_printf(MSG_DEBUG, "WPS: Received Credential");
707 	os_memset(&wps->cred, 0, sizeof(wps->cred));
708 	wpabuf_set(&msg, cred, cred_len);
709 	if (wps_parse_msg(&msg, &attr) < 0 ||
710 	    wps_process_cred(&attr, &wps->cred))
711 		return -1;
712 
713 	if (os_memcmp(wps->cred.mac_addr, wps->wps->dev.mac_addr, ETH_ALEN) !=
714 	    0) {
715 		wpa_printf(MSG_DEBUG, "WPS: MAC Address in the Credential ("
716 			   MACSTR ") does not match with own address (" MACSTR
717 			   ")", MAC2STR(wps->cred.mac_addr),
718 			   MAC2STR(wps->wps->dev.mac_addr));
719 		/*
720 		 * In theory, this could be consider fatal error, but there are
721 		 * number of deployed implementations using other address here
722 		 * due to unclarity in the specification. For interoperability
723 		 * reasons, allow this to be processed since we do not really
724 		 * use the MAC Address information for anything.
725 		 */
726 #ifdef CONFIG_WPS_STRICT
727 		if (wps2) {
728 			wpa_printf(MSG_INFO, "WPS: Do not accept incorrect "
729 				   "MAC Address in AP Settings");
730 			return -1;
731 		}
732 #endif /* CONFIG_WPS_STRICT */
733 	}
734 
735 	if (!(wps->cred.encr_type &
736 	      (WPS_ENCR_NONE | WPS_ENCR_TKIP | WPS_ENCR_AES))) {
737 		if (wps->cred.encr_type & WPS_ENCR_WEP) {
738 			wpa_printf(MSG_INFO, "WPS: Reject Credential "
739 				   "due to WEP configuration");
740 			wps->error_indication = WPS_EI_SECURITY_WEP_PROHIBITED;
741 			return -2;
742 		}
743 
744 		wpa_printf(MSG_INFO, "WPS: Reject Credential due to "
745 			   "invalid encr_type 0x%x", wps->cred.encr_type);
746 		return -1;
747 	}
748 
749 	if (wps->wps->cred_cb) {
750 		wps->cred.cred_attr = cred - 4;
751 		wps->cred.cred_attr_len = cred_len + 4;
752 		ret = wps->wps->cred_cb(wps->wps->cb_ctx, &wps->cred);
753 		wps->cred.cred_attr = NULL;
754 		wps->cred.cred_attr_len = 0;
755 	}
756 
757 	return ret;
758 }
759 
760 
wps_process_creds(struct wps_data * wps,const u8 * cred[],u16 cred_len[],unsigned int num_cred,int wps2)761 static int wps_process_creds(struct wps_data *wps, const u8 *cred[],
762 			     u16 cred_len[], unsigned int num_cred, int wps2)
763 {
764 	size_t i;
765 	int ok = 0;
766 
767 	if (wps->wps->ap)
768 		return 0;
769 
770 	if (num_cred == 0) {
771 		wpa_printf(MSG_DEBUG, "WPS: No Credential attributes "
772 			   "received");
773 		return -1;
774 	}
775 
776 	for (i = 0; i < num_cred; i++) {
777 		int res;
778 		res = wps_process_cred_e(wps, cred[i], cred_len[i], wps2);
779 		if (res == 0)
780 			ok++;
781 		else if (res == -2)
782 			wpa_printf(MSG_DEBUG, "WPS: WEP credential skipped");
783 		else
784 			return -1;
785 	}
786 
787 	if (ok == 0) {
788 		wpa_printf(MSG_DEBUG, "WPS: No valid Credential attribute "
789 			   "received");
790 		return -1;
791 	}
792 
793 	return 0;
794 }
795 
796 
wps_process_ap_settings_e(struct wps_data * wps,struct wps_parse_attr * attr,struct wpabuf * attrs,int wps2)797 static int wps_process_ap_settings_e(struct wps_data *wps,
798 				     struct wps_parse_attr *attr,
799 				     struct wpabuf *attrs, int wps2)
800 {
801 	struct wps_credential cred;
802 	int ret = 0;
803 
804 	if (!wps->wps->ap)
805 		return 0;
806 
807 	if (wps_process_ap_settings(attr, &cred) < 0)
808 		return -1;
809 
810 	wpa_printf(MSG_INFO, "WPS: Received new AP configuration from "
811 		   "Registrar");
812 
813 	if (os_memcmp(cred.mac_addr, wps->wps->dev.mac_addr, ETH_ALEN) !=
814 	    0) {
815 		wpa_printf(MSG_DEBUG, "WPS: MAC Address in the AP Settings ("
816 			   MACSTR ") does not match with own address (" MACSTR
817 			   ")", MAC2STR(cred.mac_addr),
818 			   MAC2STR(wps->wps->dev.mac_addr));
819 		/*
820 		 * In theory, this could be consider fatal error, but there are
821 		 * number of deployed implementations using other address here
822 		 * due to unclarity in the specification. For interoperability
823 		 * reasons, allow this to be processed since we do not really
824 		 * use the MAC Address information for anything.
825 		 */
826 #ifdef CONFIG_WPS_STRICT
827 		if (wps2) {
828 			wpa_printf(MSG_INFO, "WPS: Do not accept incorrect "
829 				   "MAC Address in AP Settings");
830 			return -1;
831 		}
832 #endif /* CONFIG_WPS_STRICT */
833 	}
834 
835 	if (!(cred.encr_type & (WPS_ENCR_NONE | WPS_ENCR_TKIP | WPS_ENCR_AES)))
836 	{
837 		if (cred.encr_type & WPS_ENCR_WEP) {
838 			wpa_printf(MSG_INFO, "WPS: Reject new AP settings "
839 				   "due to WEP configuration");
840 			wps->error_indication = WPS_EI_SECURITY_WEP_PROHIBITED;
841 			return -1;
842 		}
843 
844 		wpa_printf(MSG_INFO, "WPS: Reject new AP settings due to "
845 			   "invalid encr_type 0x%x", cred.encr_type);
846 		return -1;
847 	}
848 
849 #ifdef CONFIG_WPS_STRICT
850 	if (wps2) {
851 		if ((cred.encr_type & (WPS_ENCR_TKIP | WPS_ENCR_AES)) ==
852 		    WPS_ENCR_TKIP ||
853 		    (cred.auth_type & (WPS_AUTH_WPAPSK | WPS_AUTH_WPA2PSK)) ==
854 		    WPS_AUTH_WPAPSK) {
855 			wpa_printf(MSG_INFO, "WPS-STRICT: Invalid WSC 2.0 "
856 				   "AP Settings: WPA-Personal/TKIP only");
857 			wps->error_indication =
858 				WPS_EI_SECURITY_TKIP_ONLY_PROHIBITED;
859 			return -1;
860 		}
861 	}
862 #endif /* CONFIG_WPS_STRICT */
863 
864 	if ((cred.encr_type & (WPS_ENCR_TKIP | WPS_ENCR_AES)) == WPS_ENCR_TKIP)
865 	{
866 		wpa_printf(MSG_DEBUG, "WPS: Upgrade encr_type TKIP -> "
867 			   "TKIP+AES");
868 		cred.encr_type |= WPS_ENCR_AES;
869 	}
870 
871 	if ((cred.auth_type & (WPS_AUTH_WPAPSK | WPS_AUTH_WPA2PSK)) ==
872 	    WPS_AUTH_WPAPSK) {
873 		wpa_printf(MSG_DEBUG, "WPS: Upgrade auth_type WPAPSK -> "
874 			   "WPAPSK+WPA2PSK");
875 		cred.auth_type |= WPS_AUTH_WPA2PSK;
876 	}
877 
878 	if (wps->wps->cred_cb) {
879 		cred.cred_attr = wpabuf_head(attrs);
880 		cred.cred_attr_len = wpabuf_len(attrs);
881 		ret = wps->wps->cred_cb(wps->wps->cb_ctx, &cred);
882 	}
883 
884 	return ret;
885 }
886 
887 
wps_process_dev_pw_id(struct wps_data * wps,const u8 * dev_pw_id)888 static int wps_process_dev_pw_id(struct wps_data *wps, const u8 *dev_pw_id)
889 {
890 	u16 id;
891 
892 	if (dev_pw_id == NULL) {
893 		wpa_printf(MSG_DEBUG, "WPS: Device Password ID");
894 		return -1;
895 	}
896 
897 	id = WPA_GET_BE16(dev_pw_id);
898 	if (wps->dev_pw_id == id) {
899 		wpa_printf(MSG_DEBUG, "WPS: Device Password ID %u", id);
900 		return 0;
901 	}
902 
903 #ifdef CONFIG_P2P
904 	if ((id == DEV_PW_DEFAULT &&
905 	     wps->dev_pw_id == DEV_PW_REGISTRAR_SPECIFIED) ||
906 	    (id == DEV_PW_REGISTRAR_SPECIFIED &&
907 	     wps->dev_pw_id == DEV_PW_DEFAULT)) {
908 		/*
909 		 * Common P2P use cases indicate whether the PIN is from the
910 		 * client or GO using Device Password Id in M1/M2 in a way that
911 		 * does not look fully compliant with WSC specification. Anyway,
912 		 * this is deployed and needs to be allowed, so ignore changes
913 		 * between Registrar-Specified and Default PIN.
914 		 */
915 		wpa_printf(MSG_DEBUG, "WPS: Allow PIN Device Password ID "
916 			   "change");
917 		return 0;
918 	}
919 #endif /* CONFIG_P2P */
920 
921 	wpa_printf(MSG_DEBUG, "WPS: Registrar trying to change Device Password "
922 		   "ID from %u to %u", wps->dev_pw_id, id);
923 
924 	if (wps->dev_pw_id == DEV_PW_PUSHBUTTON && id == DEV_PW_DEFAULT) {
925 		wpa_printf(MSG_DEBUG,
926 			   "WPS: Workaround - ignore PBC-to-PIN change");
927 		return 0;
928 	}
929 
930 	if (wps->alt_dev_password && wps->alt_dev_pw_id == id) {
931 		wpa_printf(MSG_DEBUG, "WPS: Found a matching Device Password");
932 		bin_clear_free(wps->dev_password, wps->dev_password_len);
933 		wps->dev_pw_id = wps->alt_dev_pw_id;
934 		wps->dev_password = wps->alt_dev_password;
935 		wps->dev_password_len = wps->alt_dev_password_len;
936 		wps->alt_dev_password = NULL;
937 		wps->alt_dev_password_len = 0;
938 		return 0;
939 	}
940 
941 	return -1;
942 }
943 
944 
wps_process_m2(struct wps_data * wps,const struct wpabuf * msg,struct wps_parse_attr * attr)945 static enum wps_process_res wps_process_m2(struct wps_data *wps,
946 					   const struct wpabuf *msg,
947 					   struct wps_parse_attr *attr)
948 {
949 	wpa_printf(MSG_DEBUG, "WPS: Received M2");
950 
951 	if (wps->state != RECV_M2) {
952 		wpa_printf(MSG_DEBUG, "WPS: Unexpected state (%d) for "
953 			   "receiving M2", wps->state);
954 		wps->state = SEND_WSC_NACK;
955 		return WPS_CONTINUE;
956 	}
957 
958 	if (wps_process_registrar_nonce(wps, attr->registrar_nonce) ||
959 	    wps_process_enrollee_nonce(wps, attr->enrollee_nonce) ||
960 	    wps_process_uuid_r(wps, attr->uuid_r) ||
961 	    wps_process_dev_pw_id(wps, attr->dev_password_id)) {
962 		wps->state = SEND_WSC_NACK;
963 		return WPS_CONTINUE;
964 	}
965 
966 	/*
967 	 * Stop here on an AP as an Enrollee if AP Setup is locked unless the
968 	 * special locked mode is used to allow protocol run up to M7 in order
969 	 * to support external Registrars that only learn the current AP
970 	 * configuration without changing it.
971 	 */
972 	if (wps->wps->ap &&
973 	    ((wps->wps->ap_setup_locked && wps->wps->ap_setup_locked != 2) ||
974 	     wps->dev_password == NULL)) {
975 		wpa_printf(MSG_DEBUG, "WPS: AP Setup is locked - refuse "
976 			   "registration of a new Registrar");
977 		wps->config_error = WPS_CFG_SETUP_LOCKED;
978 		wps->state = SEND_WSC_NACK;
979 		return WPS_CONTINUE;
980 	}
981 
982 	if (wps_process_pubkey(wps, attr->public_key, attr->public_key_len) ||
983 	    wps_process_authenticator(wps, attr->authenticator, msg) ||
984 	    wps_process_device_attrs(&wps->peer_dev, attr)) {
985 		wps->state = SEND_WSC_NACK;
986 		return WPS_CONTINUE;
987 	}
988 
989 #ifdef CONFIG_WPS_NFC
990 	if (wps->peer_pubkey_hash_set) {
991 		struct wpabuf *decrypted;
992 		struct wps_parse_attr eattr;
993 
994 		decrypted = wps_decrypt_encr_settings(wps, attr->encr_settings,
995 						      attr->encr_settings_len);
996 		if (decrypted == NULL) {
997 			wpa_printf(MSG_DEBUG, "WPS: Failed to decrypt "
998 				   "Encrypted Settings attribute");
999 			wps->state = SEND_WSC_NACK;
1000 			return WPS_CONTINUE;
1001 		}
1002 
1003 		wpa_printf(MSG_DEBUG, "WPS: Processing decrypted Encrypted "
1004 			   "Settings attribute");
1005 		if (wps_parse_msg(decrypted, &eattr) < 0 ||
1006 		    wps_process_key_wrap_auth(wps, decrypted,
1007 					      eattr.key_wrap_auth) ||
1008 		    wps_process_creds(wps, eattr.cred, eattr.cred_len,
1009 				      eattr.num_cred, attr->version2 != NULL)) {
1010 			wpabuf_free(decrypted);
1011 			wps->state = SEND_WSC_NACK;
1012 			return WPS_CONTINUE;
1013 		}
1014 		wpabuf_free(decrypted);
1015 
1016 		wps->state = WPS_MSG_DONE;
1017 		return WPS_CONTINUE;
1018 	}
1019 #endif /* CONFIG_WPS_NFC */
1020 
1021 	wps->state = SEND_M3;
1022 	return WPS_CONTINUE;
1023 }
1024 
1025 
wps_process_m2d(struct wps_data * wps,struct wps_parse_attr * attr)1026 static enum wps_process_res wps_process_m2d(struct wps_data *wps,
1027 					    struct wps_parse_attr *attr)
1028 {
1029 	wpa_printf(MSG_DEBUG, "WPS: Received M2D");
1030 
1031 	if (wps->state != RECV_M2) {
1032 		wpa_printf(MSG_DEBUG, "WPS: Unexpected state (%d) for "
1033 			   "receiving M2D", wps->state);
1034 		wps->state = SEND_WSC_NACK;
1035 		return WPS_CONTINUE;
1036 	}
1037 
1038 	wpa_hexdump_ascii(MSG_DEBUG, "WPS: Manufacturer",
1039 			  attr->manufacturer, attr->manufacturer_len);
1040 	wpa_hexdump_ascii(MSG_DEBUG, "WPS: Model Name",
1041 			  attr->model_name, attr->model_name_len);
1042 	wpa_hexdump_ascii(MSG_DEBUG, "WPS: Model Number",
1043 			  attr->model_number, attr->model_number_len);
1044 	wpa_hexdump_ascii(MSG_DEBUG, "WPS: Serial Number",
1045 			  attr->serial_number, attr->serial_number_len);
1046 	wpa_hexdump_ascii(MSG_DEBUG, "WPS: Device Name",
1047 			  attr->dev_name, attr->dev_name_len);
1048 
1049 	if (wps->wps->event_cb) {
1050 		union wps_event_data data;
1051 		struct wps_event_m2d *m2d = &data.m2d;
1052 		os_memset(&data, 0, sizeof(data));
1053 		if (attr->config_methods)
1054 			m2d->config_methods =
1055 				WPA_GET_BE16(attr->config_methods);
1056 		m2d->manufacturer = attr->manufacturer;
1057 		m2d->manufacturer_len = attr->manufacturer_len;
1058 		m2d->model_name = attr->model_name;
1059 		m2d->model_name_len = attr->model_name_len;
1060 		m2d->model_number = attr->model_number;
1061 		m2d->model_number_len = attr->model_number_len;
1062 		m2d->serial_number = attr->serial_number;
1063 		m2d->serial_number_len = attr->serial_number_len;
1064 		m2d->dev_name = attr->dev_name;
1065 		m2d->dev_name_len = attr->dev_name_len;
1066 		m2d->primary_dev_type = attr->primary_dev_type;
1067 		if (attr->config_error)
1068 			m2d->config_error =
1069 				WPA_GET_BE16(attr->config_error);
1070 		if (attr->dev_password_id)
1071 			m2d->dev_password_id =
1072 				WPA_GET_BE16(attr->dev_password_id);
1073 		wps->wps->event_cb(wps->wps->cb_ctx, WPS_EV_M2D, &data);
1074 	}
1075 
1076 	wps->state = RECEIVED_M2D;
1077 	return WPS_CONTINUE;
1078 }
1079 
1080 
wps_process_m4(struct wps_data * wps,const struct wpabuf * msg,struct wps_parse_attr * attr)1081 static enum wps_process_res wps_process_m4(struct wps_data *wps,
1082 					   const struct wpabuf *msg,
1083 					   struct wps_parse_attr *attr)
1084 {
1085 	struct wpabuf *decrypted;
1086 	struct wps_parse_attr eattr;
1087 
1088 	wpa_printf(MSG_DEBUG, "WPS: Received M4");
1089 
1090 	if (wps->state != RECV_M4) {
1091 		wpa_printf(MSG_DEBUG, "WPS: Unexpected state (%d) for "
1092 			   "receiving M4", wps->state);
1093 		wps->state = SEND_WSC_NACK;
1094 		return WPS_CONTINUE;
1095 	}
1096 
1097 	if (wps_process_enrollee_nonce(wps, attr->enrollee_nonce) ||
1098 	    wps_process_authenticator(wps, attr->authenticator, msg) ||
1099 	    wps_process_r_hash1(wps, attr->r_hash1) ||
1100 	    wps_process_r_hash2(wps, attr->r_hash2)) {
1101 		wps->state = SEND_WSC_NACK;
1102 		return WPS_CONTINUE;
1103 	}
1104 
1105 	decrypted = wps_decrypt_encr_settings(wps, attr->encr_settings,
1106 					      attr->encr_settings_len);
1107 	if (decrypted == NULL) {
1108 		wpa_printf(MSG_DEBUG, "WPS: Failed to decrypted Encrypted "
1109 			   "Settings attribute");
1110 		wps->state = SEND_WSC_NACK;
1111 		return WPS_CONTINUE;
1112 	}
1113 
1114 	if (wps_validate_m4_encr(decrypted, attr->version2 != NULL) < 0) {
1115 		wpabuf_free(decrypted);
1116 		wps->state = SEND_WSC_NACK;
1117 		return WPS_CONTINUE;
1118 	}
1119 
1120 	wpa_printf(MSG_DEBUG, "WPS: Processing decrypted Encrypted Settings "
1121 		   "attribute");
1122 	if (wps_parse_msg(decrypted, &eattr) < 0 ||
1123 	    wps_process_key_wrap_auth(wps, decrypted, eattr.key_wrap_auth) ||
1124 	    wps_process_r_snonce1(wps, eattr.r_snonce1)) {
1125 		wpabuf_free(decrypted);
1126 		wps->state = SEND_WSC_NACK;
1127 		return WPS_CONTINUE;
1128 	}
1129 	wpabuf_free(decrypted);
1130 
1131 	wps->state = SEND_M5;
1132 	return WPS_CONTINUE;
1133 }
1134 
1135 
wps_process_m6(struct wps_data * wps,const struct wpabuf * msg,struct wps_parse_attr * attr)1136 static enum wps_process_res wps_process_m6(struct wps_data *wps,
1137 					   const struct wpabuf *msg,
1138 					   struct wps_parse_attr *attr)
1139 {
1140 	struct wpabuf *decrypted;
1141 	struct wps_parse_attr eattr;
1142 
1143 	wpa_printf(MSG_DEBUG, "WPS: Received M6");
1144 
1145 	if (wps->state != RECV_M6) {
1146 		wpa_printf(MSG_DEBUG, "WPS: Unexpected state (%d) for "
1147 			   "receiving M6", wps->state);
1148 		wps->state = SEND_WSC_NACK;
1149 		return WPS_CONTINUE;
1150 	}
1151 
1152 	if (wps_process_enrollee_nonce(wps, attr->enrollee_nonce) ||
1153 	    wps_process_authenticator(wps, attr->authenticator, msg)) {
1154 		wps->state = SEND_WSC_NACK;
1155 		return WPS_CONTINUE;
1156 	}
1157 
1158 	decrypted = wps_decrypt_encr_settings(wps, attr->encr_settings,
1159 					      attr->encr_settings_len);
1160 	if (decrypted == NULL) {
1161 		wpa_printf(MSG_DEBUG, "WPS: Failed to decrypted Encrypted "
1162 			   "Settings attribute");
1163 		wps->state = SEND_WSC_NACK;
1164 		return WPS_CONTINUE;
1165 	}
1166 
1167 	if (wps_validate_m6_encr(decrypted, attr->version2 != NULL) < 0) {
1168 		wpabuf_free(decrypted);
1169 		wps->state = SEND_WSC_NACK;
1170 		return WPS_CONTINUE;
1171 	}
1172 
1173 	wpa_printf(MSG_DEBUG, "WPS: Processing decrypted Encrypted Settings "
1174 		   "attribute");
1175 	if (wps_parse_msg(decrypted, &eattr) < 0 ||
1176 	    wps_process_key_wrap_auth(wps, decrypted, eattr.key_wrap_auth) ||
1177 	    wps_process_r_snonce2(wps, eattr.r_snonce2)) {
1178 		wpabuf_free(decrypted);
1179 		wps->state = SEND_WSC_NACK;
1180 		return WPS_CONTINUE;
1181 	}
1182 	wpabuf_free(decrypted);
1183 
1184 	if (wps->wps->ap)
1185 		wps->wps->event_cb(wps->wps->cb_ctx, WPS_EV_AP_PIN_SUCCESS,
1186 				   NULL);
1187 
1188 	wps->state = SEND_M7;
1189 	return WPS_CONTINUE;
1190 }
1191 
1192 
wps_process_m8(struct wps_data * wps,const struct wpabuf * msg,struct wps_parse_attr * attr)1193 static enum wps_process_res wps_process_m8(struct wps_data *wps,
1194 					   const struct wpabuf *msg,
1195 					   struct wps_parse_attr *attr)
1196 {
1197 	struct wpabuf *decrypted;
1198 	struct wps_parse_attr eattr;
1199 
1200 	wpa_printf(MSG_DEBUG, "WPS: Received M8");
1201 
1202 	if (wps->state != RECV_M8) {
1203 		wpa_printf(MSG_DEBUG, "WPS: Unexpected state (%d) for "
1204 			   "receiving M8", wps->state);
1205 		wps->state = SEND_WSC_NACK;
1206 		return WPS_CONTINUE;
1207 	}
1208 
1209 	if (wps_process_enrollee_nonce(wps, attr->enrollee_nonce) ||
1210 	    wps_process_authenticator(wps, attr->authenticator, msg)) {
1211 		wps->state = SEND_WSC_NACK;
1212 		return WPS_CONTINUE;
1213 	}
1214 
1215 	if (wps->wps->ap && wps->wps->ap_setup_locked) {
1216 		/*
1217 		 * Stop here if special ap_setup_locked == 2 mode allowed the
1218 		 * protocol to continue beyond M2. This allows ER to learn the
1219 		 * current AP settings without changing them.
1220 		 */
1221 		wpa_printf(MSG_DEBUG, "WPS: AP Setup is locked - refuse "
1222 			   "registration of a new Registrar");
1223 		wps->config_error = WPS_CFG_SETUP_LOCKED;
1224 		wps->state = SEND_WSC_NACK;
1225 		return WPS_CONTINUE;
1226 	}
1227 
1228 	decrypted = wps_decrypt_encr_settings(wps, attr->encr_settings,
1229 					      attr->encr_settings_len);
1230 	if (decrypted == NULL) {
1231 		wpa_printf(MSG_DEBUG, "WPS: Failed to decrypted Encrypted "
1232 			   "Settings attribute");
1233 		wps->state = SEND_WSC_NACK;
1234 		return WPS_CONTINUE;
1235 	}
1236 
1237 	if (wps_validate_m8_encr(decrypted, wps->wps->ap,
1238 				 attr->version2 != NULL) < 0) {
1239 		wpabuf_free(decrypted);
1240 		wps->state = SEND_WSC_NACK;
1241 		return WPS_CONTINUE;
1242 	}
1243 
1244 	wpa_printf(MSG_DEBUG, "WPS: Processing decrypted Encrypted Settings "
1245 		   "attribute");
1246 	if (wps_parse_msg(decrypted, &eattr) < 0 ||
1247 	    wps_process_key_wrap_auth(wps, decrypted, eattr.key_wrap_auth) ||
1248 	    wps_process_creds(wps, eattr.cred, eattr.cred_len,
1249 			      eattr.num_cred, attr->version2 != NULL) ||
1250 	    wps_process_ap_settings_e(wps, &eattr, decrypted,
1251 				      attr->version2 != NULL)) {
1252 		wpabuf_free(decrypted);
1253 		wps->state = SEND_WSC_NACK;
1254 		return WPS_CONTINUE;
1255 	}
1256 	wpabuf_free(decrypted);
1257 
1258 	wps->state = WPS_MSG_DONE;
1259 	return WPS_CONTINUE;
1260 }
1261 
1262 
wps_process_wsc_msg(struct wps_data * wps,const struct wpabuf * msg)1263 static enum wps_process_res wps_process_wsc_msg(struct wps_data *wps,
1264 						const struct wpabuf *msg)
1265 {
1266 	struct wps_parse_attr attr;
1267 	enum wps_process_res ret = WPS_CONTINUE;
1268 
1269 	wpa_printf(MSG_DEBUG, "WPS: Received WSC_MSG");
1270 
1271 	if (wps_parse_msg(msg, &attr) < 0)
1272 		return WPS_FAILURE;
1273 
1274 	if (attr.enrollee_nonce == NULL ||
1275 	    os_memcmp(wps->nonce_e, attr.enrollee_nonce, WPS_NONCE_LEN) != 0) {
1276 		wpa_printf(MSG_DEBUG, "WPS: Mismatch in enrollee nonce");
1277 		return WPS_FAILURE;
1278 	}
1279 
1280 	if (attr.msg_type == NULL) {
1281 		wpa_printf(MSG_DEBUG, "WPS: No Message Type attribute");
1282 		wps->state = SEND_WSC_NACK;
1283 		return WPS_CONTINUE;
1284 	}
1285 
1286 	switch (*attr.msg_type) {
1287 	case WPS_M2:
1288 		if (wps_validate_m2(msg) < 0)
1289 			return WPS_FAILURE;
1290 		ret = wps_process_m2(wps, msg, &attr);
1291 		break;
1292 	case WPS_M2D:
1293 		if (wps_validate_m2d(msg) < 0)
1294 			return WPS_FAILURE;
1295 		ret = wps_process_m2d(wps, &attr);
1296 		break;
1297 	case WPS_M4:
1298 		if (wps_validate_m4(msg) < 0)
1299 			return WPS_FAILURE;
1300 		ret = wps_process_m4(wps, msg, &attr);
1301 		if (ret == WPS_FAILURE || wps->state == SEND_WSC_NACK)
1302 			wps_fail_event(wps->wps, WPS_M4, wps->config_error,
1303 				       wps->error_indication,
1304 				       wps->peer_dev.mac_addr);
1305 		break;
1306 	case WPS_M6:
1307 		if (wps_validate_m6(msg) < 0)
1308 			return WPS_FAILURE;
1309 		ret = wps_process_m6(wps, msg, &attr);
1310 		if (ret == WPS_FAILURE || wps->state == SEND_WSC_NACK)
1311 			wps_fail_event(wps->wps, WPS_M6, wps->config_error,
1312 				       wps->error_indication,
1313 				       wps->peer_dev.mac_addr);
1314 		break;
1315 	case WPS_M8:
1316 		if (wps_validate_m8(msg) < 0)
1317 			return WPS_FAILURE;
1318 		ret = wps_process_m8(wps, msg, &attr);
1319 		if (ret == WPS_FAILURE || wps->state == SEND_WSC_NACK)
1320 			wps_fail_event(wps->wps, WPS_M8, wps->config_error,
1321 				       wps->error_indication,
1322 				       wps->peer_dev.mac_addr);
1323 		break;
1324 	default:
1325 		wpa_printf(MSG_DEBUG, "WPS: Unsupported Message Type %d",
1326 			   *attr.msg_type);
1327 		return WPS_FAILURE;
1328 	}
1329 
1330 	/*
1331 	 * Save a copy of the last message for Authenticator derivation if we
1332 	 * are continuing. However, skip M2D since it is not authenticated and
1333 	 * neither is the ACK/NACK response frame. This allows the possibly
1334 	 * following M2 to be processed correctly by using the previously sent
1335 	 * M1 in Authenticator derivation.
1336 	 */
1337 	if (ret == WPS_CONTINUE && *attr.msg_type != WPS_M2D) {
1338 		/* Save a copy of the last message for Authenticator derivation
1339 		 */
1340 		wpabuf_free(wps->last_msg);
1341 		wps->last_msg = wpabuf_dup(msg);
1342 	}
1343 
1344 	return ret;
1345 }
1346 
1347 
wps_process_wsc_ack(struct wps_data * wps,const struct wpabuf * msg)1348 static enum wps_process_res wps_process_wsc_ack(struct wps_data *wps,
1349 						const struct wpabuf *msg)
1350 {
1351 	struct wps_parse_attr attr;
1352 
1353 	wpa_printf(MSG_DEBUG, "WPS: Received WSC_ACK");
1354 
1355 	if (wps_parse_msg(msg, &attr) < 0)
1356 		return WPS_FAILURE;
1357 
1358 	if (attr.msg_type == NULL) {
1359 		wpa_printf(MSG_DEBUG, "WPS: No Message Type attribute");
1360 		return WPS_FAILURE;
1361 	}
1362 
1363 	if (*attr.msg_type != WPS_WSC_ACK) {
1364 		wpa_printf(MSG_DEBUG, "WPS: Invalid Message Type %d",
1365 			   *attr.msg_type);
1366 		return WPS_FAILURE;
1367 	}
1368 
1369 	if (attr.registrar_nonce == NULL ||
1370 	    os_memcmp(wps->nonce_r, attr.registrar_nonce, WPS_NONCE_LEN) != 0)
1371 	{
1372 		wpa_printf(MSG_DEBUG, "WPS: Mismatch in registrar nonce");
1373 		return WPS_FAILURE;
1374 	}
1375 
1376 	if (attr.enrollee_nonce == NULL ||
1377 	    os_memcmp(wps->nonce_e, attr.enrollee_nonce, WPS_NONCE_LEN) != 0) {
1378 		wpa_printf(MSG_DEBUG, "WPS: Mismatch in enrollee nonce");
1379 		return WPS_FAILURE;
1380 	}
1381 
1382 	if (wps->state == RECV_ACK && wps->wps->ap) {
1383 		wpa_printf(MSG_DEBUG, "WPS: External Registrar registration "
1384 			   "completed successfully");
1385 		wps_success_event(wps->wps, wps->peer_dev.mac_addr);
1386 		wps->state = WPS_FINISHED;
1387 		return WPS_DONE;
1388 	}
1389 
1390 	return WPS_FAILURE;
1391 }
1392 
1393 
wps_process_wsc_nack(struct wps_data * wps,const struct wpabuf * msg)1394 static enum wps_process_res wps_process_wsc_nack(struct wps_data *wps,
1395 						 const struct wpabuf *msg)
1396 {
1397 	struct wps_parse_attr attr;
1398 	u16 config_error;
1399 
1400 	wpa_printf(MSG_DEBUG, "WPS: Received WSC_NACK");
1401 
1402 	if (wps_parse_msg(msg, &attr) < 0)
1403 		return WPS_FAILURE;
1404 
1405 	if (attr.msg_type == NULL) {
1406 		wpa_printf(MSG_DEBUG, "WPS: No Message Type attribute");
1407 		return WPS_FAILURE;
1408 	}
1409 
1410 	if (*attr.msg_type != WPS_WSC_NACK) {
1411 		wpa_printf(MSG_DEBUG, "WPS: Invalid Message Type %d",
1412 			   *attr.msg_type);
1413 		return WPS_FAILURE;
1414 	}
1415 
1416 	if (attr.registrar_nonce == NULL ||
1417 	    os_memcmp(wps->nonce_r, attr.registrar_nonce, WPS_NONCE_LEN) != 0)
1418 	{
1419 		wpa_printf(MSG_DEBUG, "WPS: Mismatch in registrar nonce");
1420 		wpa_hexdump(MSG_DEBUG, "WPS: Received Registrar Nonce",
1421 			    attr.registrar_nonce, WPS_NONCE_LEN);
1422 		wpa_hexdump(MSG_DEBUG, "WPS: Expected Registrar Nonce",
1423 			    wps->nonce_r, WPS_NONCE_LEN);
1424 		return WPS_FAILURE;
1425 	}
1426 
1427 	if (attr.enrollee_nonce == NULL ||
1428 	    os_memcmp(wps->nonce_e, attr.enrollee_nonce, WPS_NONCE_LEN) != 0) {
1429 		wpa_printf(MSG_DEBUG, "WPS: Mismatch in enrollee nonce");
1430 		wpa_hexdump(MSG_DEBUG, "WPS: Received Enrollee Nonce",
1431 			    attr.enrollee_nonce, WPS_NONCE_LEN);
1432 		wpa_hexdump(MSG_DEBUG, "WPS: Expected Enrollee Nonce",
1433 			    wps->nonce_e, WPS_NONCE_LEN);
1434 		return WPS_FAILURE;
1435 	}
1436 
1437 	if (attr.config_error == NULL) {
1438 		wpa_printf(MSG_DEBUG, "WPS: No Configuration Error attribute "
1439 			   "in WSC_NACK");
1440 		return WPS_FAILURE;
1441 	}
1442 
1443 	config_error = WPA_GET_BE16(attr.config_error);
1444 	wpa_printf(MSG_DEBUG, "WPS: Registrar terminated negotiation with "
1445 		   "Configuration Error %d", config_error);
1446 
1447 	switch (wps->state) {
1448 	case RECV_M4:
1449 		wps_fail_event(wps->wps, WPS_M3, config_error,
1450 			       wps->error_indication, wps->peer_dev.mac_addr);
1451 		break;
1452 	case RECV_M6:
1453 		wps_fail_event(wps->wps, WPS_M5, config_error,
1454 			       wps->error_indication, wps->peer_dev.mac_addr);
1455 		break;
1456 	case RECV_M8:
1457 		wps_fail_event(wps->wps, WPS_M7, config_error,
1458 			       wps->error_indication, wps->peer_dev.mac_addr);
1459 		break;
1460 	default:
1461 		break;
1462 	}
1463 
1464 	/* Followed by NACK if Enrollee is Supplicant or EAP-Failure if
1465 	 * Enrollee is Authenticator */
1466 	wps->state = SEND_WSC_NACK;
1467 
1468 	return WPS_FAILURE;
1469 }
1470 
1471 
wps_enrollee_process_msg(struct wps_data * wps,enum wsc_op_code op_code,const struct wpabuf * msg)1472 enum wps_process_res wps_enrollee_process_msg(struct wps_data *wps,
1473 					      enum wsc_op_code op_code,
1474 					      const struct wpabuf *msg)
1475 {
1476 
1477 	wpa_printf(MSG_DEBUG, "WPS: Processing received message (len=%lu "
1478 		   "op_code=%d)",
1479 		   (unsigned long) wpabuf_len(msg), op_code);
1480 
1481 	if (op_code == WSC_UPnP) {
1482 		/* Determine the OpCode based on message type attribute */
1483 		struct wps_parse_attr attr;
1484 		if (wps_parse_msg(msg, &attr) == 0 && attr.msg_type) {
1485 			if (*attr.msg_type == WPS_WSC_ACK)
1486 				op_code = WSC_ACK;
1487 			else if (*attr.msg_type == WPS_WSC_NACK)
1488 				op_code = WSC_NACK;
1489 		}
1490 	}
1491 
1492 	switch (op_code) {
1493 	case WSC_MSG:
1494 	case WSC_UPnP:
1495 		return wps_process_wsc_msg(wps, msg);
1496 	case WSC_ACK:
1497 		if (wps_validate_wsc_ack(msg) < 0)
1498 			return WPS_FAILURE;
1499 		return wps_process_wsc_ack(wps, msg);
1500 	case WSC_NACK:
1501 		if (wps_validate_wsc_nack(msg) < 0)
1502 			return WPS_FAILURE;
1503 		return wps_process_wsc_nack(wps, msg);
1504 	default:
1505 		wpa_printf(MSG_DEBUG, "WPS: Unsupported op_code %d", op_code);
1506 		return WPS_FAILURE;
1507 	}
1508 }
1509