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