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 	u8 multi_ap_backhaul_sta = 0;
109 
110 	if (random_get_bytes(wps->nonce_e, WPS_NONCE_LEN) < 0)
111 		return NULL;
112 	wpa_hexdump(MSG_DEBUG, "WPS: Enrollee Nonce",
113 		    wps->nonce_e, WPS_NONCE_LEN);
114 
115 	wpa_printf(MSG_DEBUG, "WPS: Building Message M1");
116 	msg = wpabuf_alloc(1000);
117 	if (msg == NULL)
118 		return NULL;
119 
120 	config_methods = wps->wps->config_methods;
121 	if (wps->wps->ap && !wps->pbc_in_m1 &&
122 	    (wps->dev_password_len != 0 ||
123 	     (config_methods & WPS_CONFIG_DISPLAY))) {
124 		/*
125 		 * These are the methods that the AP supports as an Enrollee
126 		 * for adding external Registrars, so remove PushButton.
127 		 *
128 		 * As a workaround for Windows 7 mechanism for probing WPS
129 		 * capabilities from M1, leave PushButton option if no PIN
130 		 * method is available or if WPS configuration enables PBC
131 		 * workaround.
132 		 */
133 		config_methods &= ~WPS_CONFIG_PUSHBUTTON;
134 		config_methods &= ~(WPS_CONFIG_VIRT_PUSHBUTTON |
135 				    WPS_CONFIG_PHY_PUSHBUTTON);
136 	}
137 
138 	if (wps->multi_ap_backhaul_sta)
139 		multi_ap_backhaul_sta = MULTI_AP_BACKHAUL_STA;
140 
141 	if (wps_build_version(msg) ||
142 	    wps_build_msg_type(msg, WPS_M1) ||
143 	    wps_build_uuid_e(msg, wps->uuid_e) ||
144 	    wps_build_mac_addr(msg, wps->mac_addr_e) ||
145 	    wps_build_enrollee_nonce(wps, msg) ||
146 	    wps_build_public_key(wps, msg) ||
147 	    wps_build_auth_type_flags(wps, msg) ||
148 	    wps_build_encr_type_flags(wps, msg) ||
149 	    wps_build_conn_type_flags(wps, msg) ||
150 	    wps_build_config_methods(msg, config_methods) ||
151 	    wps_build_wps_state(wps, msg) ||
152 	    wps_build_device_attrs(&wps->wps->dev, msg) ||
153 	    wps_build_rf_bands(&wps->wps->dev, msg,
154 			       wps->wps->rf_band_cb(wps->wps->cb_ctx)) ||
155 	    wps_build_assoc_state(wps, msg) ||
156 	    wps_build_dev_password_id(msg, wps->dev_pw_id) ||
157 	    wps_build_config_error(msg, WPS_CFG_NO_ERROR) ||
158 	    wps_build_os_version(&wps->wps->dev, msg) ||
159 	    wps_build_wfa_ext(msg, 0, NULL, 0, multi_ap_backhaul_sta) ||
160 	    wps_build_vendor_ext_m1(&wps->wps->dev, msg)) {
161 		wpabuf_free(msg);
162 		return NULL;
163 	}
164 
165 	wps->state = RECV_M2;
166 	return msg;
167 }
168 
169 
wps_build_m3(struct wps_data * wps)170 static struct wpabuf * wps_build_m3(struct wps_data *wps)
171 {
172 	struct wpabuf *msg;
173 
174 	wpa_printf(MSG_DEBUG, "WPS: Building Message M3");
175 
176 	if (wps->dev_password == NULL) {
177 		wpa_printf(MSG_DEBUG, "WPS: No Device Password available");
178 		return NULL;
179 	}
180 	if (wps_derive_psk(wps, wps->dev_password, wps->dev_password_len) < 0)
181 		return NULL;
182 
183 	if (wps->wps->ap && random_pool_ready() != 1) {
184 		wpa_printf(MSG_INFO,
185 			   "WPS: Not enough entropy in random pool to proceed - do not allow AP PIN to be used");
186 		return NULL;
187 	}
188 
189 	msg = wpabuf_alloc(1000);
190 	if (msg == NULL)
191 		return NULL;
192 
193 	if (wps_build_version(msg) ||
194 	    wps_build_msg_type(msg, WPS_M3) ||
195 	    wps_build_registrar_nonce(wps, msg) ||
196 	    wps_build_e_hash(wps, msg) ||
197 	    wps_build_wfa_ext(msg, 0, NULL, 0, 0) ||
198 	    wps_build_authenticator(wps, msg)) {
199 		wpabuf_free(msg);
200 		return NULL;
201 	}
202 
203 	wps->state = RECV_M4;
204 	return msg;
205 }
206 
207 
wps_build_m5(struct wps_data * wps)208 static struct wpabuf * wps_build_m5(struct wps_data *wps)
209 {
210 	struct wpabuf *msg, *plain;
211 
212 	wpa_printf(MSG_DEBUG, "WPS: Building Message M5");
213 
214 	plain = wpabuf_alloc(200);
215 	if (plain == NULL)
216 		return NULL;
217 
218 	msg = wpabuf_alloc(1000);
219 	if (msg == NULL) {
220 		wpabuf_free(plain);
221 		return NULL;
222 	}
223 
224 	if (wps_build_version(msg) ||
225 	    wps_build_msg_type(msg, WPS_M5) ||
226 	    wps_build_registrar_nonce(wps, msg) ||
227 	    wps_build_e_snonce1(wps, plain) ||
228 	    wps_build_key_wrap_auth(wps, plain) ||
229 	    wps_build_encr_settings(wps, msg, plain) ||
230 	    wps_build_wfa_ext(msg, 0, NULL, 0, 0) ||
231 	    wps_build_authenticator(wps, msg)) {
232 		wpabuf_clear_free(plain);
233 		wpabuf_free(msg);
234 		return NULL;
235 	}
236 	wpabuf_clear_free(plain);
237 
238 	wps->state = RECV_M6;
239 	return msg;
240 }
241 
242 
wps_build_cred_ssid(struct wps_data * wps,struct wpabuf * msg)243 static int wps_build_cred_ssid(struct wps_data *wps, struct wpabuf *msg)
244 {
245 	wpa_printf(MSG_DEBUG, "WPS:  * SSID");
246 	wpabuf_put_be16(msg, ATTR_SSID);
247 	wpabuf_put_be16(msg, wps->wps->ssid_len);
248 	wpabuf_put_data(msg, wps->wps->ssid, wps->wps->ssid_len);
249 	return 0;
250 }
251 
252 
wps_build_cred_auth_type(struct wps_data * wps,struct wpabuf * msg)253 static int wps_build_cred_auth_type(struct wps_data *wps, struct wpabuf *msg)
254 {
255 	u16 auth_type = wps->wps->ap_auth_type;
256 
257 	/*
258 	 * Work around issues with Windows 7 WPS implementation not liking
259 	 * multiple Authentication Type bits in M7 AP Settings attribute by
260 	 * showing only the most secure option from current configuration.
261 	 */
262 	if (auth_type & WPS_AUTH_WPA2PSK)
263 		auth_type = WPS_AUTH_WPA2PSK;
264 	else if (auth_type & WPS_AUTH_WPAPSK)
265 		auth_type = WPS_AUTH_WPAPSK;
266 	else if (auth_type & WPS_AUTH_OPEN)
267 		auth_type = WPS_AUTH_OPEN;
268 
269 	wpa_printf(MSG_DEBUG, "WPS:  * Authentication Type (0x%x)", auth_type);
270 	wpabuf_put_be16(msg, ATTR_AUTH_TYPE);
271 	wpabuf_put_be16(msg, 2);
272 	wpabuf_put_be16(msg, auth_type);
273 	return 0;
274 }
275 
276 
wps_build_cred_encr_type(struct wps_data * wps,struct wpabuf * msg)277 static int wps_build_cred_encr_type(struct wps_data *wps, struct wpabuf *msg)
278 {
279 	u16 encr_type = wps->wps->ap_encr_type;
280 
281 	/*
282 	 * Work around issues with Windows 7 WPS implementation not liking
283 	 * multiple Encryption Type bits in M7 AP Settings attribute by
284 	 * showing only the most secure option from current configuration.
285 	 */
286 	if (wps->wps->ap_auth_type & (WPS_AUTH_WPA2PSK | WPS_AUTH_WPAPSK)) {
287 		if (encr_type & WPS_ENCR_AES)
288 			encr_type = WPS_ENCR_AES;
289 		else if (encr_type & WPS_ENCR_TKIP)
290 			encr_type = WPS_ENCR_TKIP;
291 	}
292 
293 	wpa_printf(MSG_DEBUG, "WPS:  * Encryption Type (0x%x)", encr_type);
294 	wpabuf_put_be16(msg, ATTR_ENCR_TYPE);
295 	wpabuf_put_be16(msg, 2);
296 	wpabuf_put_be16(msg, encr_type);
297 	return 0;
298 }
299 
300 
wps_build_cred_network_key(struct wps_data * wps,struct wpabuf * msg)301 static int wps_build_cred_network_key(struct wps_data *wps, struct wpabuf *msg)
302 {
303 	if ((wps->wps->ap_auth_type & (WPS_AUTH_WPAPSK | WPS_AUTH_WPA2PSK)) &&
304 	    wps->wps->network_key_len == 0) {
305 		char hex[65];
306 		u8 psk[32];
307 		/* Generate a random per-device PSK */
308 		if (random_pool_ready() != 1 ||
309 		    random_get_bytes(psk, sizeof(psk)) < 0) {
310 			wpa_printf(MSG_INFO,
311 				   "WPS: Could not generate random PSK");
312 			return -1;
313 		}
314 		wpa_hexdump_key(MSG_DEBUG, "WPS: Generated per-device PSK",
315 				psk, sizeof(psk));
316 		wpa_printf(MSG_DEBUG, "WPS:  * Network Key (len=%u)",
317 			   (unsigned int) wps->new_psk_len * 2);
318 		wpa_snprintf_hex(hex, sizeof(hex), psk, sizeof(psk));
319 		wpabuf_put_be16(msg, ATTR_NETWORK_KEY);
320 		wpabuf_put_be16(msg, sizeof(psk) * 2);
321 		wpabuf_put_data(msg, hex, sizeof(psk) * 2);
322 		if (wps->wps->registrar) {
323 			wps_cb_new_psk(wps->wps->registrar,
324 				       wps->peer_dev.mac_addr,
325 				       wps->p2p_dev_addr, psk, sizeof(psk));
326 		}
327 		return 0;
328 	}
329 
330 	wpa_printf(MSG_DEBUG, "WPS:  * Network Key (len=%u)",
331 		   (unsigned int) wps->wps->network_key_len);
332 	wpabuf_put_be16(msg, ATTR_NETWORK_KEY);
333 	wpabuf_put_be16(msg, wps->wps->network_key_len);
334 	wpabuf_put_data(msg, wps->wps->network_key, wps->wps->network_key_len);
335 	return 0;
336 }
337 
338 
wps_build_cred_mac_addr(struct wps_data * wps,struct wpabuf * msg)339 static int wps_build_cred_mac_addr(struct wps_data *wps, struct wpabuf *msg)
340 {
341 	wpa_printf(MSG_DEBUG, "WPS:  * MAC Address (AP BSSID)");
342 	wpabuf_put_be16(msg, ATTR_MAC_ADDR);
343 	wpabuf_put_be16(msg, ETH_ALEN);
344 	wpabuf_put_data(msg, wps->wps->dev.mac_addr, ETH_ALEN);
345 	return 0;
346 }
347 
348 
wps_build_ap_settings(struct wps_data * wps,struct wpabuf * plain)349 static int wps_build_ap_settings(struct wps_data *wps, struct wpabuf *plain)
350 {
351 	const u8 *start, *end;
352 	int ret;
353 
354 	if (wps->wps->ap_settings) {
355 		wpa_printf(MSG_DEBUG, "WPS:  * AP Settings (pre-configured)");
356 		wpabuf_put_data(plain, wps->wps->ap_settings,
357 				wps->wps->ap_settings_len);
358 		return 0;
359 	}
360 
361 	wpa_printf(MSG_DEBUG, "WPS:  * AP Settings based on current configuration");
362 	start = wpabuf_put(plain, 0);
363 	ret = wps_build_cred_ssid(wps, plain) ||
364 		wps_build_cred_mac_addr(wps, plain) ||
365 		wps_build_cred_auth_type(wps, plain) ||
366 		wps_build_cred_encr_type(wps, plain) ||
367 		wps_build_cred_network_key(wps, plain);
368 	end = wpabuf_put(plain, 0);
369 
370 	wpa_hexdump_key(MSG_DEBUG, "WPS: Plaintext AP Settings",
371 			start, end - start);
372 
373 	return ret;
374 }
375 
376 
wps_build_m7(struct wps_data * wps)377 static struct wpabuf * wps_build_m7(struct wps_data *wps)
378 {
379 	struct wpabuf *msg, *plain;
380 
381 	wpa_printf(MSG_DEBUG, "WPS: Building Message M7");
382 
383 	plain = wpabuf_alloc(500 + wps->wps->ap_settings_len);
384 	if (plain == NULL)
385 		return NULL;
386 
387 	msg = wpabuf_alloc(1000 + wps->wps->ap_settings_len);
388 	if (msg == NULL) {
389 		wpabuf_free(plain);
390 		return NULL;
391 	}
392 
393 	if (wps_build_version(msg) ||
394 	    wps_build_msg_type(msg, WPS_M7) ||
395 	    wps_build_registrar_nonce(wps, msg) ||
396 	    wps_build_e_snonce2(wps, plain) ||
397 	    (wps->wps->ap && wps_build_ap_settings(wps, plain)) ||
398 	    wps_build_key_wrap_auth(wps, plain) ||
399 	    wps_build_encr_settings(wps, msg, plain) ||
400 	    wps_build_wfa_ext(msg, 0, NULL, 0, 0) ||
401 	    wps_build_authenticator(wps, msg)) {
402 		wpabuf_clear_free(plain);
403 		wpabuf_free(msg);
404 		return NULL;
405 	}
406 	wpabuf_clear_free(plain);
407 
408 	if (wps->wps->ap && wps->wps->registrar) {
409 		/*
410 		 * If the Registrar is only learning our current configuration,
411 		 * it may not continue protocol run to successful completion.
412 		 * Store information here to make sure it remains available.
413 		 */
414 		wps_device_store(wps->wps->registrar, &wps->peer_dev,
415 				 wps->uuid_r);
416 	}
417 
418 	wps->state = RECV_M8;
419 	return msg;
420 }
421 
422 
wps_build_wsc_done(struct wps_data * wps)423 static struct wpabuf * wps_build_wsc_done(struct wps_data *wps)
424 {
425 	struct wpabuf *msg;
426 
427 	wpa_printf(MSG_DEBUG, "WPS: Building Message WSC_Done");
428 
429 	msg = wpabuf_alloc(1000);
430 	if (msg == NULL)
431 		return NULL;
432 
433 	if (wps_build_version(msg) ||
434 	    wps_build_msg_type(msg, WPS_WSC_DONE) ||
435 	    wps_build_enrollee_nonce(wps, msg) ||
436 	    wps_build_registrar_nonce(wps, msg) ||
437 	    wps_build_wfa_ext(msg, 0, NULL, 0, 0)) {
438 		wpabuf_free(msg);
439 		return NULL;
440 	}
441 
442 	if (wps->wps->ap)
443 		wps->state = RECV_ACK;
444 	else {
445 		wps_success_event(wps->wps, wps->peer_dev.mac_addr);
446 		wps->state = WPS_FINISHED;
447 	}
448 	return msg;
449 }
450 
451 
wps_enrollee_get_msg(struct wps_data * wps,enum wsc_op_code * op_code)452 struct wpabuf * wps_enrollee_get_msg(struct wps_data *wps,
453 				     enum wsc_op_code *op_code)
454 {
455 	struct wpabuf *msg;
456 
457 	switch (wps->state) {
458 	case SEND_M1:
459 		msg = wps_build_m1(wps);
460 		*op_code = WSC_MSG;
461 		break;
462 	case SEND_M3:
463 		msg = wps_build_m3(wps);
464 		*op_code = WSC_MSG;
465 		break;
466 	case SEND_M5:
467 		msg = wps_build_m5(wps);
468 		*op_code = WSC_MSG;
469 		break;
470 	case SEND_M7:
471 		msg = wps_build_m7(wps);
472 		*op_code = WSC_MSG;
473 		break;
474 	case RECEIVED_M2D:
475 		if (wps->wps->ap) {
476 			msg = wps_build_wsc_nack(wps);
477 			*op_code = WSC_NACK;
478 			break;
479 		}
480 		msg = wps_build_wsc_ack(wps);
481 		*op_code = WSC_ACK;
482 		if (msg) {
483 			/* Another M2/M2D may be received */
484 			wps->state = RECV_M2;
485 		}
486 		break;
487 	case SEND_WSC_NACK:
488 		msg = wps_build_wsc_nack(wps);
489 		*op_code = WSC_NACK;
490 		break;
491 	case WPS_MSG_DONE:
492 		msg = wps_build_wsc_done(wps);
493 		*op_code = WSC_Done;
494 		break;
495 	default:
496 		wpa_printf(MSG_DEBUG, "WPS: Unsupported state %d for building "
497 			   "a message", wps->state);
498 		msg = NULL;
499 		break;
500 	}
501 
502 	if (*op_code == WSC_MSG && msg) {
503 		/* Save a copy of the last message for Authenticator derivation
504 		 */
505 		wpabuf_free(wps->last_msg);
506 		wps->last_msg = wpabuf_dup(msg);
507 	}
508 
509 	return msg;
510 }
511 
512 
wps_process_registrar_nonce(struct wps_data * wps,const u8 * r_nonce)513 static int wps_process_registrar_nonce(struct wps_data *wps, const u8 *r_nonce)
514 {
515 	if (r_nonce == NULL) {
516 		wpa_printf(MSG_DEBUG, "WPS: No Registrar Nonce received");
517 		return -1;
518 	}
519 
520 	os_memcpy(wps->nonce_r, r_nonce, WPS_NONCE_LEN);
521 	wpa_hexdump(MSG_DEBUG, "WPS: Registrar Nonce",
522 		    wps->nonce_r, WPS_NONCE_LEN);
523 
524 	return 0;
525 }
526 
527 
wps_process_enrollee_nonce(struct wps_data * wps,const u8 * e_nonce)528 static int wps_process_enrollee_nonce(struct wps_data *wps, const u8 *e_nonce)
529 {
530 	if (e_nonce == NULL) {
531 		wpa_printf(MSG_DEBUG, "WPS: No Enrollee Nonce received");
532 		return -1;
533 	}
534 
535 	if (os_memcmp(wps->nonce_e, e_nonce, WPS_NONCE_LEN) != 0) {
536 		wpa_printf(MSG_DEBUG, "WPS: Invalid Enrollee Nonce received");
537 		return -1;
538 	}
539 
540 	return 0;
541 }
542 
543 
wps_process_uuid_r(struct wps_data * wps,const u8 * uuid_r)544 static int wps_process_uuid_r(struct wps_data *wps, const u8 *uuid_r)
545 {
546 	if (uuid_r == NULL) {
547 		wpa_printf(MSG_DEBUG, "WPS: No UUID-R received");
548 		return -1;
549 	}
550 
551 	os_memcpy(wps->uuid_r, uuid_r, WPS_UUID_LEN);
552 	wpa_hexdump(MSG_DEBUG, "WPS: UUID-R", wps->uuid_r, WPS_UUID_LEN);
553 
554 	return 0;
555 }
556 
557 
wps_process_pubkey(struct wps_data * wps,const u8 * pk,size_t pk_len)558 static int wps_process_pubkey(struct wps_data *wps, const u8 *pk,
559 			      size_t pk_len)
560 {
561 	if (pk == NULL || pk_len == 0) {
562 		wpa_printf(MSG_DEBUG, "WPS: No Public Key received");
563 		return -1;
564 	}
565 
566 	if (wps->peer_pubkey_hash_set) {
567 		u8 hash[WPS_HASH_LEN];
568 		sha256_vector(1, &pk, &pk_len, hash);
569 		if (os_memcmp_const(hash, wps->peer_pubkey_hash,
570 				    WPS_OOB_PUBKEY_HASH_LEN) != 0) {
571 			wpa_printf(MSG_ERROR, "WPS: Public Key hash mismatch");
572 			wpa_hexdump(MSG_DEBUG, "WPS: Received public key",
573 				    pk, pk_len);
574 			wpa_hexdump(MSG_DEBUG, "WPS: Calculated public key "
575 				    "hash", hash, WPS_OOB_PUBKEY_HASH_LEN);
576 			wpa_hexdump(MSG_DEBUG, "WPS: Expected public key hash",
577 				    wps->peer_pubkey_hash,
578 				    WPS_OOB_PUBKEY_HASH_LEN);
579 			wps->config_error = WPS_CFG_PUBLIC_KEY_HASH_MISMATCH;
580 			return -1;
581 		}
582 	}
583 
584 	wpabuf_free(wps->dh_pubkey_r);
585 	wps->dh_pubkey_r = wpabuf_alloc_copy(pk, pk_len);
586 	if (wps->dh_pubkey_r == NULL)
587 		return -1;
588 
589 	if (wps_derive_keys(wps) < 0)
590 		return -1;
591 
592 	return 0;
593 }
594 
595 
wps_process_r_hash1(struct wps_data * wps,const u8 * r_hash1)596 static int wps_process_r_hash1(struct wps_data *wps, const u8 *r_hash1)
597 {
598 	if (r_hash1 == NULL) {
599 		wpa_printf(MSG_DEBUG, "WPS: No R-Hash1 received");
600 		return -1;
601 	}
602 
603 	os_memcpy(wps->peer_hash1, r_hash1, WPS_HASH_LEN);
604 	wpa_hexdump(MSG_DEBUG, "WPS: R-Hash1", wps->peer_hash1, WPS_HASH_LEN);
605 
606 	return 0;
607 }
608 
609 
wps_process_r_hash2(struct wps_data * wps,const u8 * r_hash2)610 static int wps_process_r_hash2(struct wps_data *wps, const u8 *r_hash2)
611 {
612 	if (r_hash2 == NULL) {
613 		wpa_printf(MSG_DEBUG, "WPS: No R-Hash2 received");
614 		return -1;
615 	}
616 
617 	os_memcpy(wps->peer_hash2, r_hash2, WPS_HASH_LEN);
618 	wpa_hexdump(MSG_DEBUG, "WPS: R-Hash2", wps->peer_hash2, WPS_HASH_LEN);
619 
620 	return 0;
621 }
622 
623 
wps_process_r_snonce1(struct wps_data * wps,const u8 * r_snonce1)624 static int wps_process_r_snonce1(struct wps_data *wps, const u8 *r_snonce1)
625 {
626 	u8 hash[SHA256_MAC_LEN];
627 	const u8 *addr[4];
628 	size_t len[4];
629 
630 	if (r_snonce1 == NULL) {
631 		wpa_printf(MSG_DEBUG, "WPS: No R-SNonce1 received");
632 		return -1;
633 	}
634 
635 	wpa_hexdump_key(MSG_DEBUG, "WPS: R-SNonce1", r_snonce1,
636 			WPS_SECRET_NONCE_LEN);
637 
638 	/* R-Hash1 = HMAC_AuthKey(R-S1 || PSK1 || PK_E || PK_R) */
639 	addr[0] = r_snonce1;
640 	len[0] = WPS_SECRET_NONCE_LEN;
641 	addr[1] = wps->psk1;
642 	len[1] = WPS_PSK_LEN;
643 	addr[2] = wpabuf_head(wps->dh_pubkey_e);
644 	len[2] = wpabuf_len(wps->dh_pubkey_e);
645 	addr[3] = wpabuf_head(wps->dh_pubkey_r);
646 	len[3] = wpabuf_len(wps->dh_pubkey_r);
647 	hmac_sha256_vector(wps->authkey, WPS_AUTHKEY_LEN, 4, addr, len, hash);
648 
649 	if (os_memcmp_const(wps->peer_hash1, hash, WPS_HASH_LEN) != 0) {
650 		wpa_printf(MSG_DEBUG, "WPS: R-Hash1 derived from R-S1 does "
651 			   "not match with the pre-committed value");
652 		wps->config_error = WPS_CFG_DEV_PASSWORD_AUTH_FAILURE;
653 		wps_pwd_auth_fail_event(wps->wps, 1, 1, wps->peer_dev.mac_addr);
654 		return -1;
655 	}
656 
657 	wpa_printf(MSG_DEBUG, "WPS: Registrar proved knowledge of the first "
658 		   "half of the device password");
659 
660 	return 0;
661 }
662 
663 
wps_process_r_snonce2(struct wps_data * wps,const u8 * r_snonce2)664 static int wps_process_r_snonce2(struct wps_data *wps, const u8 *r_snonce2)
665 {
666 	u8 hash[SHA256_MAC_LEN];
667 	const u8 *addr[4];
668 	size_t len[4];
669 
670 	if (r_snonce2 == NULL) {
671 		wpa_printf(MSG_DEBUG, "WPS: No R-SNonce2 received");
672 		return -1;
673 	}
674 
675 	wpa_hexdump_key(MSG_DEBUG, "WPS: R-SNonce2", r_snonce2,
676 			WPS_SECRET_NONCE_LEN);
677 
678 	/* R-Hash2 = HMAC_AuthKey(R-S2 || PSK2 || PK_E || PK_R) */
679 	addr[0] = r_snonce2;
680 	len[0] = WPS_SECRET_NONCE_LEN;
681 	addr[1] = wps->psk2;
682 	len[1] = WPS_PSK_LEN;
683 	addr[2] = wpabuf_head(wps->dh_pubkey_e);
684 	len[2] = wpabuf_len(wps->dh_pubkey_e);
685 	addr[3] = wpabuf_head(wps->dh_pubkey_r);
686 	len[3] = wpabuf_len(wps->dh_pubkey_r);
687 	hmac_sha256_vector(wps->authkey, WPS_AUTHKEY_LEN, 4, addr, len, hash);
688 
689 	if (os_memcmp_const(wps->peer_hash2, hash, WPS_HASH_LEN) != 0) {
690 		wpa_printf(MSG_DEBUG, "WPS: R-Hash2 derived from R-S2 does "
691 			   "not match with the pre-committed value");
692 		wps->config_error = WPS_CFG_DEV_PASSWORD_AUTH_FAILURE;
693 		wps_pwd_auth_fail_event(wps->wps, 1, 2, wps->peer_dev.mac_addr);
694 		return -1;
695 	}
696 
697 	wpa_printf(MSG_DEBUG, "WPS: Registrar proved knowledge of the second "
698 		   "half of the device password");
699 
700 	return 0;
701 }
702 
703 
wps_process_cred_e(struct wps_data * wps,const u8 * cred,size_t cred_len,int wps2)704 static int wps_process_cred_e(struct wps_data *wps, const u8 *cred,
705 			      size_t cred_len, int wps2)
706 {
707 	struct wps_parse_attr attr;
708 	struct wpabuf msg;
709 	int ret = 0;
710 
711 	wpa_printf(MSG_DEBUG, "WPS: Received Credential");
712 	os_memset(&wps->cred, 0, sizeof(wps->cred));
713 	wpabuf_set(&msg, cred, cred_len);
714 	if (wps_parse_msg(&msg, &attr) < 0 ||
715 	    wps_process_cred(&attr, &wps->cred))
716 		return -1;
717 
718 	if (os_memcmp(wps->cred.mac_addr, wps->wps->dev.mac_addr, ETH_ALEN) !=
719 	    0) {
720 		wpa_printf(MSG_DEBUG, "WPS: MAC Address in the Credential ("
721 			   MACSTR ") does not match with own address (" MACSTR
722 			   ")", MAC2STR(wps->cred.mac_addr),
723 			   MAC2STR(wps->wps->dev.mac_addr));
724 		/*
725 		 * In theory, this could be consider fatal error, but there are
726 		 * number of deployed implementations using other address here
727 		 * due to unclarity in the specification. For interoperability
728 		 * reasons, allow this to be processed since we do not really
729 		 * use the MAC Address information for anything.
730 		 */
731 #ifdef CONFIG_WPS_STRICT
732 		if (wps2) {
733 			wpa_printf(MSG_INFO, "WPS: Do not accept incorrect "
734 				   "MAC Address in AP Settings");
735 			return -1;
736 		}
737 #endif /* CONFIG_WPS_STRICT */
738 	}
739 
740 	if (!(wps->cred.encr_type &
741 	      (WPS_ENCR_NONE | WPS_ENCR_TKIP | WPS_ENCR_AES))) {
742 		if (wps->cred.encr_type & WPS_ENCR_WEP) {
743 			wpa_printf(MSG_INFO, "WPS: Reject Credential "
744 				   "due to WEP configuration");
745 			wps->error_indication = WPS_EI_SECURITY_WEP_PROHIBITED;
746 			return -2;
747 		}
748 
749 		wpa_printf(MSG_INFO, "WPS: Reject Credential due to "
750 			   "invalid encr_type 0x%x", wps->cred.encr_type);
751 		return -1;
752 	}
753 
754 	if (wps->wps->cred_cb) {
755 		wps->cred.cred_attr = cred - 4;
756 		wps->cred.cred_attr_len = cred_len + 4;
757 		ret = wps->wps->cred_cb(wps->wps->cb_ctx, &wps->cred);
758 		wps->cred.cred_attr = NULL;
759 		wps->cred.cred_attr_len = 0;
760 	}
761 
762 	return ret;
763 }
764 
765 
wps_process_creds(struct wps_data * wps,const u8 * cred[],u16 cred_len[],unsigned int num_cred,int wps2)766 static int wps_process_creds(struct wps_data *wps, const u8 *cred[],
767 			     u16 cred_len[], unsigned int num_cred, int wps2)
768 {
769 	size_t i;
770 	int ok = 0;
771 
772 	if (wps->wps->ap)
773 		return 0;
774 
775 	if (num_cred == 0) {
776 		wpa_printf(MSG_DEBUG, "WPS: No Credential attributes "
777 			   "received");
778 		return -1;
779 	}
780 
781 	for (i = 0; i < num_cred; i++) {
782 		int res;
783 		res = wps_process_cred_e(wps, cred[i], cred_len[i], wps2);
784 		if (res == 0)
785 			ok++;
786 		else if (res == -2)
787 			wpa_printf(MSG_DEBUG, "WPS: WEP credential skipped");
788 		else
789 			return -1;
790 	}
791 
792 	if (ok == 0) {
793 		wpa_printf(MSG_DEBUG, "WPS: No valid Credential attribute "
794 			   "received");
795 		return -1;
796 	}
797 
798 	return 0;
799 }
800 
801 
wps_process_ap_settings_e(struct wps_data * wps,struct wps_parse_attr * attr,struct wpabuf * attrs,int wps2)802 static int wps_process_ap_settings_e(struct wps_data *wps,
803 				     struct wps_parse_attr *attr,
804 				     struct wpabuf *attrs, int wps2)
805 {
806 	struct wps_credential cred;
807 	int ret = 0;
808 
809 	if (!wps->wps->ap)
810 		return 0;
811 
812 	if (wps_process_ap_settings(attr, &cred) < 0)
813 		return -1;
814 
815 	wpa_printf(MSG_INFO, "WPS: Received new AP configuration from "
816 		   "Registrar");
817 
818 	if (os_memcmp(cred.mac_addr, wps->wps->dev.mac_addr, ETH_ALEN) !=
819 	    0) {
820 		wpa_printf(MSG_DEBUG, "WPS: MAC Address in the AP Settings ("
821 			   MACSTR ") does not match with own address (" MACSTR
822 			   ")", MAC2STR(cred.mac_addr),
823 			   MAC2STR(wps->wps->dev.mac_addr));
824 		/*
825 		 * In theory, this could be consider fatal error, but there are
826 		 * number of deployed implementations using other address here
827 		 * due to unclarity in the specification. For interoperability
828 		 * reasons, allow this to be processed since we do not really
829 		 * use the MAC Address information for anything.
830 		 */
831 #ifdef CONFIG_WPS_STRICT
832 		if (wps2) {
833 			wpa_printf(MSG_INFO, "WPS: Do not accept incorrect "
834 				   "MAC Address in AP Settings");
835 			return -1;
836 		}
837 #endif /* CONFIG_WPS_STRICT */
838 	}
839 
840 	if (!(cred.encr_type & (WPS_ENCR_NONE | WPS_ENCR_TKIP | WPS_ENCR_AES)))
841 	{
842 		if (cred.encr_type & WPS_ENCR_WEP) {
843 			wpa_printf(MSG_INFO, "WPS: Reject new AP settings "
844 				   "due to WEP configuration");
845 			wps->error_indication = WPS_EI_SECURITY_WEP_PROHIBITED;
846 			return -1;
847 		}
848 
849 		wpa_printf(MSG_INFO, "WPS: Reject new AP settings due to "
850 			   "invalid encr_type 0x%x", cred.encr_type);
851 		return -1;
852 	}
853 
854 #ifdef CONFIG_WPS_STRICT
855 	if (wps2) {
856 		if ((cred.encr_type & (WPS_ENCR_TKIP | WPS_ENCR_AES)) ==
857 		    WPS_ENCR_TKIP ||
858 		    (cred.auth_type & (WPS_AUTH_WPAPSK | WPS_AUTH_WPA2PSK)) ==
859 		    WPS_AUTH_WPAPSK) {
860 			wpa_printf(MSG_INFO, "WPS-STRICT: Invalid WSC 2.0 "
861 				   "AP Settings: WPA-Personal/TKIP only");
862 			wps->error_indication =
863 				WPS_EI_SECURITY_TKIP_ONLY_PROHIBITED;
864 			return -1;
865 		}
866 	}
867 #endif /* CONFIG_WPS_STRICT */
868 
869 	if ((cred.encr_type & (WPS_ENCR_TKIP | WPS_ENCR_AES)) == WPS_ENCR_TKIP)
870 	{
871 		wpa_printf(MSG_DEBUG, "WPS: Upgrade encr_type TKIP -> "
872 			   "TKIP+AES");
873 		cred.encr_type |= WPS_ENCR_AES;
874 	}
875 
876 	if ((cred.auth_type & (WPS_AUTH_WPAPSK | WPS_AUTH_WPA2PSK)) ==
877 	    WPS_AUTH_WPAPSK) {
878 		wpa_printf(MSG_DEBUG, "WPS: Upgrade auth_type WPAPSK -> "
879 			   "WPAPSK+WPA2PSK");
880 		cred.auth_type |= WPS_AUTH_WPA2PSK;
881 	}
882 
883 	if (wps->wps->cred_cb) {
884 		cred.cred_attr = wpabuf_head(attrs);
885 		cred.cred_attr_len = wpabuf_len(attrs);
886 		ret = wps->wps->cred_cb(wps->wps->cb_ctx, &cred);
887 	}
888 
889 	return ret;
890 }
891 
892 
wps_process_dev_pw_id(struct wps_data * wps,const u8 * dev_pw_id)893 static int wps_process_dev_pw_id(struct wps_data *wps, const u8 *dev_pw_id)
894 {
895 	u16 id;
896 
897 	if (dev_pw_id == NULL) {
898 		wpa_printf(MSG_DEBUG, "WPS: Device Password ID");
899 		return -1;
900 	}
901 
902 	id = WPA_GET_BE16(dev_pw_id);
903 	if (wps->dev_pw_id == id) {
904 		wpa_printf(MSG_DEBUG, "WPS: Device Password ID %u", id);
905 		return 0;
906 	}
907 
908 #ifdef CONFIG_P2P
909 	if ((id == DEV_PW_DEFAULT &&
910 	     wps->dev_pw_id == DEV_PW_REGISTRAR_SPECIFIED) ||
911 	    (id == DEV_PW_REGISTRAR_SPECIFIED &&
912 	     wps->dev_pw_id == DEV_PW_DEFAULT)) {
913 		/*
914 		 * Common P2P use cases indicate whether the PIN is from the
915 		 * client or GO using Device Password Id in M1/M2 in a way that
916 		 * does not look fully compliant with WSC specification. Anyway,
917 		 * this is deployed and needs to be allowed, so ignore changes
918 		 * between Registrar-Specified and Default PIN.
919 		 */
920 		wpa_printf(MSG_DEBUG, "WPS: Allow PIN Device Password ID "
921 			   "change");
922 		return 0;
923 	}
924 #endif /* CONFIG_P2P */
925 
926 	wpa_printf(MSG_DEBUG, "WPS: Registrar trying to change Device Password "
927 		   "ID from %u to %u", wps->dev_pw_id, id);
928 
929 	if (wps->dev_pw_id == DEV_PW_PUSHBUTTON && id == DEV_PW_DEFAULT) {
930 		wpa_printf(MSG_DEBUG,
931 			   "WPS: Workaround - ignore PBC-to-PIN change");
932 		return 0;
933 	}
934 
935 	if (wps->alt_dev_password && wps->alt_dev_pw_id == id) {
936 		wpa_printf(MSG_DEBUG, "WPS: Found a matching Device Password");
937 		bin_clear_free(wps->dev_password, wps->dev_password_len);
938 		wps->dev_pw_id = wps->alt_dev_pw_id;
939 		wps->dev_password = wps->alt_dev_password;
940 		wps->dev_password_len = wps->alt_dev_password_len;
941 		wps->alt_dev_password = NULL;
942 		wps->alt_dev_password_len = 0;
943 		return 0;
944 	}
945 
946 	return -1;
947 }
948 
949 
wps_process_m2(struct wps_data * wps,const struct wpabuf * msg,struct wps_parse_attr * attr)950 static enum wps_process_res wps_process_m2(struct wps_data *wps,
951 					   const struct wpabuf *msg,
952 					   struct wps_parse_attr *attr)
953 {
954 	wpa_printf(MSG_DEBUG, "WPS: Received M2");
955 
956 	if (wps->state != RECV_M2) {
957 		wpa_printf(MSG_DEBUG, "WPS: Unexpected state (%d) for "
958 			   "receiving M2", wps->state);
959 		wps->state = SEND_WSC_NACK;
960 		return WPS_CONTINUE;
961 	}
962 
963 	if (wps_process_registrar_nonce(wps, attr->registrar_nonce) ||
964 	    wps_process_enrollee_nonce(wps, attr->enrollee_nonce) ||
965 	    wps_process_uuid_r(wps, attr->uuid_r) ||
966 	    wps_process_dev_pw_id(wps, attr->dev_password_id)) {
967 		wps->state = SEND_WSC_NACK;
968 		return WPS_CONTINUE;
969 	}
970 
971 	/*
972 	 * Stop here on an AP as an Enrollee if AP Setup is locked unless the
973 	 * special locked mode is used to allow protocol run up to M7 in order
974 	 * to support external Registrars that only learn the current AP
975 	 * configuration without changing it.
976 	 */
977 	if (wps->wps->ap &&
978 	    ((wps->wps->ap_setup_locked && wps->wps->ap_setup_locked != 2) ||
979 	     wps->dev_password == NULL)) {
980 		wpa_printf(MSG_DEBUG, "WPS: AP Setup is locked - refuse "
981 			   "registration of a new Registrar");
982 		wps->config_error = WPS_CFG_SETUP_LOCKED;
983 		wps->state = SEND_WSC_NACK;
984 		return WPS_CONTINUE;
985 	}
986 
987 	if (wps_process_pubkey(wps, attr->public_key, attr->public_key_len) ||
988 	    wps_process_authenticator(wps, attr->authenticator, msg) ||
989 	    wps_process_device_attrs(&wps->peer_dev, attr)) {
990 		wps->state = SEND_WSC_NACK;
991 		return WPS_CONTINUE;
992 	}
993 
994 #ifdef CONFIG_WPS_NFC
995 	if (wps->peer_pubkey_hash_set) {
996 		struct wpabuf *decrypted;
997 		struct wps_parse_attr eattr;
998 
999 		decrypted = wps_decrypt_encr_settings(wps, attr->encr_settings,
1000 						      attr->encr_settings_len);
1001 		if (decrypted == NULL) {
1002 			wpa_printf(MSG_DEBUG, "WPS: Failed to decrypt "
1003 				   "Encrypted Settings attribute");
1004 			wps->state = SEND_WSC_NACK;
1005 			return WPS_CONTINUE;
1006 		}
1007 
1008 		wpa_printf(MSG_DEBUG, "WPS: Processing decrypted Encrypted "
1009 			   "Settings attribute");
1010 		if (wps_parse_msg(decrypted, &eattr) < 0 ||
1011 		    wps_process_key_wrap_auth(wps, decrypted,
1012 					      eattr.key_wrap_auth) ||
1013 		    wps_process_creds(wps, eattr.cred, eattr.cred_len,
1014 				      eattr.num_cred, attr->version2 != NULL)) {
1015 			wpabuf_clear_free(decrypted);
1016 			wps->state = SEND_WSC_NACK;
1017 			return WPS_CONTINUE;
1018 		}
1019 		wpabuf_clear_free(decrypted);
1020 
1021 		wps->state = WPS_MSG_DONE;
1022 		return WPS_CONTINUE;
1023 	}
1024 #endif /* CONFIG_WPS_NFC */
1025 
1026 	wps->state = SEND_M3;
1027 	return WPS_CONTINUE;
1028 }
1029 
1030 
wps_process_m2d(struct wps_data * wps,struct wps_parse_attr * attr)1031 static enum wps_process_res wps_process_m2d(struct wps_data *wps,
1032 					    struct wps_parse_attr *attr)
1033 {
1034 	wpa_printf(MSG_DEBUG, "WPS: Received M2D");
1035 
1036 	if (wps->state != RECV_M2) {
1037 		wpa_printf(MSG_DEBUG, "WPS: Unexpected state (%d) for "
1038 			   "receiving M2D", wps->state);
1039 		wps->state = SEND_WSC_NACK;
1040 		return WPS_CONTINUE;
1041 	}
1042 
1043 	wpa_hexdump_ascii(MSG_DEBUG, "WPS: Manufacturer",
1044 			  attr->manufacturer, attr->manufacturer_len);
1045 	wpa_hexdump_ascii(MSG_DEBUG, "WPS: Model Name",
1046 			  attr->model_name, attr->model_name_len);
1047 	wpa_hexdump_ascii(MSG_DEBUG, "WPS: Model Number",
1048 			  attr->model_number, attr->model_number_len);
1049 	wpa_hexdump_ascii(MSG_DEBUG, "WPS: Serial Number",
1050 			  attr->serial_number, attr->serial_number_len);
1051 	wpa_hexdump_ascii(MSG_DEBUG, "WPS: Device Name",
1052 			  attr->dev_name, attr->dev_name_len);
1053 
1054 	if (wps->wps->event_cb) {
1055 		union wps_event_data data;
1056 		struct wps_event_m2d *m2d = &data.m2d;
1057 		os_memset(&data, 0, sizeof(data));
1058 		if (attr->config_methods)
1059 			m2d->config_methods =
1060 				WPA_GET_BE16(attr->config_methods);
1061 		m2d->manufacturer = attr->manufacturer;
1062 		m2d->manufacturer_len = attr->manufacturer_len;
1063 		m2d->model_name = attr->model_name;
1064 		m2d->model_name_len = attr->model_name_len;
1065 		m2d->model_number = attr->model_number;
1066 		m2d->model_number_len = attr->model_number_len;
1067 		m2d->serial_number = attr->serial_number;
1068 		m2d->serial_number_len = attr->serial_number_len;
1069 		m2d->dev_name = attr->dev_name;
1070 		m2d->dev_name_len = attr->dev_name_len;
1071 		m2d->primary_dev_type = attr->primary_dev_type;
1072 		if (attr->config_error)
1073 			m2d->config_error =
1074 				WPA_GET_BE16(attr->config_error);
1075 		if (attr->dev_password_id)
1076 			m2d->dev_password_id =
1077 				WPA_GET_BE16(attr->dev_password_id);
1078 		wps->wps->event_cb(wps->wps->cb_ctx, WPS_EV_M2D, &data);
1079 	}
1080 
1081 	wps->state = RECEIVED_M2D;
1082 	return WPS_CONTINUE;
1083 }
1084 
1085 
wps_process_m4(struct wps_data * wps,const struct wpabuf * msg,struct wps_parse_attr * attr)1086 static enum wps_process_res wps_process_m4(struct wps_data *wps,
1087 					   const struct wpabuf *msg,
1088 					   struct wps_parse_attr *attr)
1089 {
1090 	struct wpabuf *decrypted;
1091 	struct wps_parse_attr eattr;
1092 
1093 	wpa_printf(MSG_DEBUG, "WPS: Received M4");
1094 
1095 	if (wps->state != RECV_M4) {
1096 		wpa_printf(MSG_DEBUG, "WPS: Unexpected state (%d) for "
1097 			   "receiving M4", wps->state);
1098 		wps->state = SEND_WSC_NACK;
1099 		return WPS_CONTINUE;
1100 	}
1101 
1102 	if (wps_process_enrollee_nonce(wps, attr->enrollee_nonce) ||
1103 	    wps_process_authenticator(wps, attr->authenticator, msg) ||
1104 	    wps_process_r_hash1(wps, attr->r_hash1) ||
1105 	    wps_process_r_hash2(wps, attr->r_hash2)) {
1106 		wps->state = SEND_WSC_NACK;
1107 		return WPS_CONTINUE;
1108 	}
1109 
1110 	decrypted = wps_decrypt_encr_settings(wps, attr->encr_settings,
1111 					      attr->encr_settings_len);
1112 	if (decrypted == NULL) {
1113 		wpa_printf(MSG_DEBUG, "WPS: Failed to decrypted Encrypted "
1114 			   "Settings attribute");
1115 		wps->state = SEND_WSC_NACK;
1116 		return WPS_CONTINUE;
1117 	}
1118 
1119 	if (wps_validate_m4_encr(decrypted, attr->version2 != NULL) < 0) {
1120 		wpabuf_clear_free(decrypted);
1121 		wps->state = SEND_WSC_NACK;
1122 		return WPS_CONTINUE;
1123 	}
1124 
1125 	wpa_printf(MSG_DEBUG, "WPS: Processing decrypted Encrypted Settings "
1126 		   "attribute");
1127 	if (wps_parse_msg(decrypted, &eattr) < 0 ||
1128 	    wps_process_key_wrap_auth(wps, decrypted, eattr.key_wrap_auth) ||
1129 	    wps_process_r_snonce1(wps, eattr.r_snonce1)) {
1130 		wpabuf_clear_free(decrypted);
1131 		wps->state = SEND_WSC_NACK;
1132 		return WPS_CONTINUE;
1133 	}
1134 	wpabuf_clear_free(decrypted);
1135 
1136 	wps->state = SEND_M5;
1137 	return WPS_CONTINUE;
1138 }
1139 
1140 
wps_process_m6(struct wps_data * wps,const struct wpabuf * msg,struct wps_parse_attr * attr)1141 static enum wps_process_res wps_process_m6(struct wps_data *wps,
1142 					   const struct wpabuf *msg,
1143 					   struct wps_parse_attr *attr)
1144 {
1145 	struct wpabuf *decrypted;
1146 	struct wps_parse_attr eattr;
1147 
1148 	wpa_printf(MSG_DEBUG, "WPS: Received M6");
1149 
1150 	if (wps->state != RECV_M6) {
1151 		wpa_printf(MSG_DEBUG, "WPS: Unexpected state (%d) for "
1152 			   "receiving M6", wps->state);
1153 		wps->state = SEND_WSC_NACK;
1154 		return WPS_CONTINUE;
1155 	}
1156 
1157 	if (wps_process_enrollee_nonce(wps, attr->enrollee_nonce) ||
1158 	    wps_process_authenticator(wps, attr->authenticator, msg)) {
1159 		wps->state = SEND_WSC_NACK;
1160 		return WPS_CONTINUE;
1161 	}
1162 
1163 	decrypted = wps_decrypt_encr_settings(wps, attr->encr_settings,
1164 					      attr->encr_settings_len);
1165 	if (decrypted == NULL) {
1166 		wpa_printf(MSG_DEBUG, "WPS: Failed to decrypted Encrypted "
1167 			   "Settings attribute");
1168 		wps->state = SEND_WSC_NACK;
1169 		return WPS_CONTINUE;
1170 	}
1171 
1172 	if (wps_validate_m6_encr(decrypted, attr->version2 != NULL) < 0) {
1173 		wpabuf_clear_free(decrypted);
1174 		wps->state = SEND_WSC_NACK;
1175 		return WPS_CONTINUE;
1176 	}
1177 
1178 	wpa_printf(MSG_DEBUG, "WPS: Processing decrypted Encrypted Settings "
1179 		   "attribute");
1180 	if (wps_parse_msg(decrypted, &eattr) < 0 ||
1181 	    wps_process_key_wrap_auth(wps, decrypted, eattr.key_wrap_auth) ||
1182 	    wps_process_r_snonce2(wps, eattr.r_snonce2)) {
1183 		wpabuf_clear_free(decrypted);
1184 		wps->state = SEND_WSC_NACK;
1185 		return WPS_CONTINUE;
1186 	}
1187 	wpabuf_clear_free(decrypted);
1188 
1189 	if (wps->wps->ap)
1190 		wps->wps->event_cb(wps->wps->cb_ctx, WPS_EV_AP_PIN_SUCCESS,
1191 				   NULL);
1192 
1193 	wps->state = SEND_M7;
1194 	return WPS_CONTINUE;
1195 }
1196 
1197 
wps_process_m8(struct wps_data * wps,const struct wpabuf * msg,struct wps_parse_attr * attr)1198 static enum wps_process_res wps_process_m8(struct wps_data *wps,
1199 					   const struct wpabuf *msg,
1200 					   struct wps_parse_attr *attr)
1201 {
1202 	struct wpabuf *decrypted;
1203 	struct wps_parse_attr eattr;
1204 
1205 	wpa_printf(MSG_DEBUG, "WPS: Received M8");
1206 
1207 	if (wps->state != RECV_M8) {
1208 		wpa_printf(MSG_DEBUG, "WPS: Unexpected state (%d) for "
1209 			   "receiving M8", wps->state);
1210 		wps->state = SEND_WSC_NACK;
1211 		return WPS_CONTINUE;
1212 	}
1213 
1214 	if (wps_process_enrollee_nonce(wps, attr->enrollee_nonce) ||
1215 	    wps_process_authenticator(wps, attr->authenticator, msg)) {
1216 		wps->state = SEND_WSC_NACK;
1217 		return WPS_CONTINUE;
1218 	}
1219 
1220 	if (wps->wps->ap && wps->wps->ap_setup_locked) {
1221 		/*
1222 		 * Stop here if special ap_setup_locked == 2 mode allowed the
1223 		 * protocol to continue beyond M2. This allows ER to learn the
1224 		 * current AP settings without changing them.
1225 		 */
1226 		wpa_printf(MSG_DEBUG, "WPS: AP Setup is locked - refuse "
1227 			   "registration of a new Registrar");
1228 		wps->config_error = WPS_CFG_SETUP_LOCKED;
1229 		wps->state = SEND_WSC_NACK;
1230 		return WPS_CONTINUE;
1231 	}
1232 
1233 	decrypted = wps_decrypt_encr_settings(wps, attr->encr_settings,
1234 					      attr->encr_settings_len);
1235 	if (decrypted == NULL) {
1236 		wpa_printf(MSG_DEBUG, "WPS: Failed to decrypted Encrypted "
1237 			   "Settings attribute");
1238 		wps->state = SEND_WSC_NACK;
1239 		return WPS_CONTINUE;
1240 	}
1241 
1242 	if (wps_validate_m8_encr(decrypted, wps->wps->ap,
1243 				 attr->version2 != NULL) < 0) {
1244 		wpabuf_clear_free(decrypted);
1245 		wps->state = SEND_WSC_NACK;
1246 		return WPS_CONTINUE;
1247 	}
1248 
1249 	wpa_printf(MSG_DEBUG, "WPS: Processing decrypted Encrypted Settings "
1250 		   "attribute");
1251 	if (wps_parse_msg(decrypted, &eattr) < 0 ||
1252 	    wps_process_key_wrap_auth(wps, decrypted, eattr.key_wrap_auth) ||
1253 	    wps_process_creds(wps, eattr.cred, eattr.cred_len,
1254 			      eattr.num_cred, attr->version2 != NULL) ||
1255 	    wps_process_ap_settings_e(wps, &eattr, decrypted,
1256 				      attr->version2 != NULL)) {
1257 		wpabuf_clear_free(decrypted);
1258 		wps->state = SEND_WSC_NACK;
1259 		return WPS_CONTINUE;
1260 	}
1261 	wpabuf_clear_free(decrypted);
1262 
1263 	wps->state = WPS_MSG_DONE;
1264 	return WPS_CONTINUE;
1265 }
1266 
1267 
wps_process_wsc_msg(struct wps_data * wps,const struct wpabuf * msg)1268 static enum wps_process_res wps_process_wsc_msg(struct wps_data *wps,
1269 						const struct wpabuf *msg)
1270 {
1271 	struct wps_parse_attr attr;
1272 	enum wps_process_res ret = WPS_CONTINUE;
1273 
1274 	wpa_printf(MSG_DEBUG, "WPS: Received WSC_MSG");
1275 
1276 	if (wps_parse_msg(msg, &attr) < 0)
1277 		return WPS_FAILURE;
1278 
1279 	if (attr.enrollee_nonce == NULL ||
1280 	    os_memcmp(wps->nonce_e, attr.enrollee_nonce, WPS_NONCE_LEN) != 0) {
1281 		wpa_printf(MSG_DEBUG, "WPS: Mismatch in enrollee nonce");
1282 		return WPS_FAILURE;
1283 	}
1284 
1285 	if (attr.msg_type == NULL) {
1286 		wpa_printf(MSG_DEBUG, "WPS: No Message Type attribute");
1287 		wps->state = SEND_WSC_NACK;
1288 		return WPS_CONTINUE;
1289 	}
1290 
1291 	switch (*attr.msg_type) {
1292 	case WPS_M2:
1293 		if (wps_validate_m2(msg) < 0)
1294 			return WPS_FAILURE;
1295 		ret = wps_process_m2(wps, msg, &attr);
1296 		break;
1297 	case WPS_M2D:
1298 		if (wps_validate_m2d(msg) < 0)
1299 			return WPS_FAILURE;
1300 		ret = wps_process_m2d(wps, &attr);
1301 		break;
1302 	case WPS_M4:
1303 		if (wps_validate_m4(msg) < 0)
1304 			return WPS_FAILURE;
1305 		ret = wps_process_m4(wps, msg, &attr);
1306 		if (ret == WPS_FAILURE || wps->state == SEND_WSC_NACK)
1307 			wps_fail_event(wps->wps, WPS_M4, wps->config_error,
1308 				       wps->error_indication,
1309 				       wps->peer_dev.mac_addr);
1310 		break;
1311 	case WPS_M6:
1312 		if (wps_validate_m6(msg) < 0)
1313 			return WPS_FAILURE;
1314 		ret = wps_process_m6(wps, msg, &attr);
1315 		if (ret == WPS_FAILURE || wps->state == SEND_WSC_NACK)
1316 			wps_fail_event(wps->wps, WPS_M6, wps->config_error,
1317 				       wps->error_indication,
1318 				       wps->peer_dev.mac_addr);
1319 		break;
1320 	case WPS_M8:
1321 		if (wps_validate_m8(msg) < 0)
1322 			return WPS_FAILURE;
1323 		ret = wps_process_m8(wps, msg, &attr);
1324 		if (ret == WPS_FAILURE || wps->state == SEND_WSC_NACK)
1325 			wps_fail_event(wps->wps, WPS_M8, wps->config_error,
1326 				       wps->error_indication,
1327 				       wps->peer_dev.mac_addr);
1328 		break;
1329 	default:
1330 		wpa_printf(MSG_DEBUG, "WPS: Unsupported Message Type %d",
1331 			   *attr.msg_type);
1332 		return WPS_FAILURE;
1333 	}
1334 
1335 	/*
1336 	 * Save a copy of the last message for Authenticator derivation if we
1337 	 * are continuing. However, skip M2D since it is not authenticated and
1338 	 * neither is the ACK/NACK response frame. This allows the possibly
1339 	 * following M2 to be processed correctly by using the previously sent
1340 	 * M1 in Authenticator derivation.
1341 	 */
1342 	if (ret == WPS_CONTINUE && *attr.msg_type != WPS_M2D) {
1343 		/* Save a copy of the last message for Authenticator derivation
1344 		 */
1345 		wpabuf_free(wps->last_msg);
1346 		wps->last_msg = wpabuf_dup(msg);
1347 	}
1348 
1349 	return ret;
1350 }
1351 
1352 
wps_process_wsc_ack(struct wps_data * wps,const struct wpabuf * msg)1353 static enum wps_process_res wps_process_wsc_ack(struct wps_data *wps,
1354 						const struct wpabuf *msg)
1355 {
1356 	struct wps_parse_attr attr;
1357 
1358 	wpa_printf(MSG_DEBUG, "WPS: Received WSC_ACK");
1359 
1360 	if (wps_parse_msg(msg, &attr) < 0)
1361 		return WPS_FAILURE;
1362 
1363 	if (attr.msg_type == NULL) {
1364 		wpa_printf(MSG_DEBUG, "WPS: No Message Type attribute");
1365 		return WPS_FAILURE;
1366 	}
1367 
1368 	if (*attr.msg_type != WPS_WSC_ACK) {
1369 		wpa_printf(MSG_DEBUG, "WPS: Invalid Message Type %d",
1370 			   *attr.msg_type);
1371 		return WPS_FAILURE;
1372 	}
1373 
1374 	if (attr.registrar_nonce == NULL ||
1375 	    os_memcmp(wps->nonce_r, attr.registrar_nonce, WPS_NONCE_LEN) != 0)
1376 	{
1377 		wpa_printf(MSG_DEBUG, "WPS: Mismatch in registrar nonce");
1378 		return WPS_FAILURE;
1379 	}
1380 
1381 	if (attr.enrollee_nonce == NULL ||
1382 	    os_memcmp(wps->nonce_e, attr.enrollee_nonce, WPS_NONCE_LEN) != 0) {
1383 		wpa_printf(MSG_DEBUG, "WPS: Mismatch in enrollee nonce");
1384 		return WPS_FAILURE;
1385 	}
1386 
1387 	if (wps->state == RECV_ACK && wps->wps->ap) {
1388 		wpa_printf(MSG_DEBUG, "WPS: External Registrar registration "
1389 			   "completed successfully");
1390 		wps_success_event(wps->wps, wps->peer_dev.mac_addr);
1391 		wps->state = WPS_FINISHED;
1392 		return WPS_DONE;
1393 	}
1394 
1395 	return WPS_FAILURE;
1396 }
1397 
1398 
wps_process_wsc_nack(struct wps_data * wps,const struct wpabuf * msg)1399 static enum wps_process_res wps_process_wsc_nack(struct wps_data *wps,
1400 						 const struct wpabuf *msg)
1401 {
1402 	struct wps_parse_attr attr;
1403 	u16 config_error;
1404 
1405 	wpa_printf(MSG_DEBUG, "WPS: Received WSC_NACK");
1406 
1407 	if (wps_parse_msg(msg, &attr) < 0)
1408 		return WPS_FAILURE;
1409 
1410 	if (attr.msg_type == NULL) {
1411 		wpa_printf(MSG_DEBUG, "WPS: No Message Type attribute");
1412 		return WPS_FAILURE;
1413 	}
1414 
1415 	if (*attr.msg_type != WPS_WSC_NACK) {
1416 		wpa_printf(MSG_DEBUG, "WPS: Invalid Message Type %d",
1417 			   *attr.msg_type);
1418 		return WPS_FAILURE;
1419 	}
1420 
1421 	if (attr.registrar_nonce == NULL ||
1422 	    os_memcmp(wps->nonce_r, attr.registrar_nonce, WPS_NONCE_LEN) != 0)
1423 	{
1424 		wpa_printf(MSG_DEBUG, "WPS: Mismatch in registrar nonce");
1425 		wpa_hexdump(MSG_DEBUG, "WPS: Received Registrar Nonce",
1426 			    attr.registrar_nonce, WPS_NONCE_LEN);
1427 		wpa_hexdump(MSG_DEBUG, "WPS: Expected Registrar Nonce",
1428 			    wps->nonce_r, WPS_NONCE_LEN);
1429 		return WPS_FAILURE;
1430 	}
1431 
1432 	if (attr.enrollee_nonce == NULL ||
1433 	    os_memcmp(wps->nonce_e, attr.enrollee_nonce, WPS_NONCE_LEN) != 0) {
1434 		wpa_printf(MSG_DEBUG, "WPS: Mismatch in enrollee nonce");
1435 		wpa_hexdump(MSG_DEBUG, "WPS: Received Enrollee Nonce",
1436 			    attr.enrollee_nonce, WPS_NONCE_LEN);
1437 		wpa_hexdump(MSG_DEBUG, "WPS: Expected Enrollee Nonce",
1438 			    wps->nonce_e, WPS_NONCE_LEN);
1439 		return WPS_FAILURE;
1440 	}
1441 
1442 	if (attr.config_error == NULL) {
1443 		wpa_printf(MSG_DEBUG, "WPS: No Configuration Error attribute "
1444 			   "in WSC_NACK");
1445 		return WPS_FAILURE;
1446 	}
1447 
1448 	config_error = WPA_GET_BE16(attr.config_error);
1449 	wpa_printf(MSG_DEBUG, "WPS: Registrar terminated negotiation with "
1450 		   "Configuration Error %d", config_error);
1451 
1452 	switch (wps->state) {
1453 	case RECV_M4:
1454 		wps_fail_event(wps->wps, WPS_M3, config_error,
1455 			       wps->error_indication, wps->peer_dev.mac_addr);
1456 		break;
1457 	case RECV_M6:
1458 		wps_fail_event(wps->wps, WPS_M5, config_error,
1459 			       wps->error_indication, wps->peer_dev.mac_addr);
1460 		break;
1461 	case RECV_M8:
1462 		wps_fail_event(wps->wps, WPS_M7, config_error,
1463 			       wps->error_indication, wps->peer_dev.mac_addr);
1464 		break;
1465 	default:
1466 		break;
1467 	}
1468 
1469 	/* Followed by NACK if Enrollee is Supplicant or EAP-Failure if
1470 	 * Enrollee is Authenticator */
1471 	wps->state = SEND_WSC_NACK;
1472 
1473 	return WPS_FAILURE;
1474 }
1475 
1476 
wps_enrollee_process_msg(struct wps_data * wps,enum wsc_op_code op_code,const struct wpabuf * msg)1477 enum wps_process_res wps_enrollee_process_msg(struct wps_data *wps,
1478 					      enum wsc_op_code op_code,
1479 					      const struct wpabuf *msg)
1480 {
1481 
1482 	wpa_printf(MSG_DEBUG, "WPS: Processing received message (len=%lu "
1483 		   "op_code=%d)",
1484 		   (unsigned long) wpabuf_len(msg), op_code);
1485 
1486 	if (op_code == WSC_UPnP) {
1487 		/* Determine the OpCode based on message type attribute */
1488 		struct wps_parse_attr attr;
1489 		if (wps_parse_msg(msg, &attr) == 0 && attr.msg_type) {
1490 			if (*attr.msg_type == WPS_WSC_ACK)
1491 				op_code = WSC_ACK;
1492 			else if (*attr.msg_type == WPS_WSC_NACK)
1493 				op_code = WSC_NACK;
1494 		}
1495 	}
1496 
1497 	switch (op_code) {
1498 	case WSC_MSG:
1499 	case WSC_UPnP:
1500 		return wps_process_wsc_msg(wps, msg);
1501 	case WSC_ACK:
1502 		if (wps_validate_wsc_ack(msg) < 0)
1503 			return WPS_FAILURE;
1504 		return wps_process_wsc_ack(wps, msg);
1505 	case WSC_NACK:
1506 		if (wps_validate_wsc_nack(msg) < 0)
1507 			return WPS_FAILURE;
1508 		return wps_process_wsc_nack(wps, msg);
1509 	default:
1510 		wpa_printf(MSG_DEBUG, "WPS: Unsupported op_code %d", op_code);
1511 		return WPS_FAILURE;
1512 	}
1513 }
1514