1/*
2 * Wi-Fi Protected Setup - attribute parsing
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 "wps_defs.h"
13#include "wps_attr_parse.h"
14
15#ifndef CONFIG_WPS_STRICT
16#define WPS_WORKAROUNDS
17#endif /* CONFIG_WPS_STRICT */
18
19
20static int wps_set_vendor_ext_wfa_subelem(struct wps_parse_attr *attr,
21					  u8 id, u8 len, const u8 *pos)
22{
23	wpa_printf(MSG_EXCESSIVE, "WPS: WFA subelement id=%u len=%u",
24		   id, len);
25	switch (id) {
26	case WFA_ELEM_VERSION2:
27		if (len != 1) {
28			wpa_printf(MSG_DEBUG, "WPS: Invalid Version2 length "
29				   "%u", len);
30			return -1;
31		}
32		attr->version2 = pos;
33		break;
34	case WFA_ELEM_AUTHORIZEDMACS:
35		attr->authorized_macs = pos;
36		attr->authorized_macs_len = len;
37		break;
38	case WFA_ELEM_NETWORK_KEY_SHAREABLE:
39		if (len != 1) {
40			wpa_printf(MSG_DEBUG, "WPS: Invalid Network Key "
41				   "Shareable length %u", len);
42			return -1;
43		}
44		attr->network_key_shareable = pos;
45		break;
46	case WFA_ELEM_REQUEST_TO_ENROLL:
47		if (len != 1) {
48			wpa_printf(MSG_DEBUG, "WPS: Invalid Request to Enroll "
49				   "length %u", len);
50			return -1;
51		}
52		attr->request_to_enroll = pos;
53		break;
54	case WFA_ELEM_SETTINGS_DELAY_TIME:
55		if (len != 1) {
56			wpa_printf(MSG_DEBUG, "WPS: Invalid Settings Delay "
57				   "Time length %u", len);
58			return -1;
59		}
60		attr->settings_delay_time = pos;
61		break;
62	case WFA_ELEM_REGISTRAR_CONFIGURATION_METHODS:
63		if (len != 2) {
64			wpa_printf(MSG_DEBUG, "WPS: Invalid Registrar Configuration Methods length %u",
65				   len);
66			return -1;
67		}
68		attr->registrar_configuration_methods = pos;
69		break;
70	default:
71		wpa_printf(MSG_MSGDUMP, "WPS: Skipped unknown WFA Vendor "
72			   "Extension subelement %u", id);
73		break;
74	}
75
76	return 0;
77}
78
79
80static int wps_parse_vendor_ext_wfa(struct wps_parse_attr *attr, const u8 *pos,
81				    u16 len)
82{
83	const u8 *end = pos + len;
84	u8 id, elen;
85
86	while (end - pos >= 2) {
87		id = *pos++;
88		elen = *pos++;
89		if (elen > end - pos)
90			break;
91		if (wps_set_vendor_ext_wfa_subelem(attr, id, elen, pos) < 0)
92			return -1;
93		pos += elen;
94	}
95
96	return 0;
97}
98
99
100static int wps_parse_vendor_ext(struct wps_parse_attr *attr, const u8 *pos,
101				u16 len)
102{
103	u32 vendor_id;
104
105	if (len < 3) {
106		wpa_printf(MSG_DEBUG, "WPS: Skip invalid Vendor Extension");
107		return 0;
108	}
109
110	vendor_id = WPA_GET_BE24(pos);
111	switch (vendor_id) {
112	case WPS_VENDOR_ID_WFA:
113		return wps_parse_vendor_ext_wfa(attr, pos + 3, len - 3);
114	}
115
116	/* Handle unknown vendor extensions */
117
118	wpa_printf(MSG_MSGDUMP, "WPS: Unknown Vendor Extension (Vendor ID %u)",
119		   vendor_id);
120
121	if (len > WPS_MAX_VENDOR_EXT_LEN) {
122		wpa_printf(MSG_DEBUG, "WPS: Too long Vendor Extension (%u)",
123			   len);
124		return -1;
125	}
126
127	if (attr->num_vendor_ext >= MAX_WPS_PARSE_VENDOR_EXT) {
128		wpa_printf(MSG_DEBUG, "WPS: Skipped Vendor Extension "
129			   "attribute (max %d vendor extensions)",
130			   MAX_WPS_PARSE_VENDOR_EXT);
131		return -1;
132	}
133	attr->vendor_ext[attr->num_vendor_ext] = pos;
134	attr->vendor_ext_len[attr->num_vendor_ext] = len;
135	attr->num_vendor_ext++;
136
137	return 0;
138}
139
140
141static int wps_set_attr(struct wps_parse_attr *attr, u16 type,
142			const u8 *pos, u16 len)
143{
144	switch (type) {
145	case ATTR_VERSION:
146		if (len != 1) {
147			wpa_printf(MSG_DEBUG, "WPS: Invalid Version length %u",
148				   len);
149			return -1;
150		}
151		attr->version = pos;
152		break;
153	case ATTR_MSG_TYPE:
154		if (len != 1) {
155			wpa_printf(MSG_DEBUG, "WPS: Invalid Message Type "
156				   "length %u", len);
157			return -1;
158		}
159		attr->msg_type = pos;
160		break;
161	case ATTR_ENROLLEE_NONCE:
162		if (len != WPS_NONCE_LEN) {
163			wpa_printf(MSG_DEBUG, "WPS: Invalid Enrollee Nonce "
164				   "length %u", len);
165			return -1;
166		}
167		attr->enrollee_nonce = pos;
168		break;
169	case ATTR_REGISTRAR_NONCE:
170		if (len != WPS_NONCE_LEN) {
171			wpa_printf(MSG_DEBUG, "WPS: Invalid Registrar Nonce "
172				   "length %u", len);
173			return -1;
174		}
175		attr->registrar_nonce = pos;
176		break;
177	case ATTR_UUID_E:
178		if (len != WPS_UUID_LEN) {
179			wpa_printf(MSG_DEBUG, "WPS: Invalid UUID-E length %u",
180				   len);
181			return -1;
182		}
183		attr->uuid_e = pos;
184		break;
185	case ATTR_UUID_R:
186		if (len != WPS_UUID_LEN) {
187			wpa_printf(MSG_DEBUG, "WPS: Invalid UUID-R length %u",
188				   len);
189			return -1;
190		}
191		attr->uuid_r = pos;
192		break;
193	case ATTR_AUTH_TYPE_FLAGS:
194		if (len != 2) {
195			wpa_printf(MSG_DEBUG, "WPS: Invalid Authentication "
196				   "Type Flags length %u", len);
197			return -1;
198		}
199		attr->auth_type_flags = pos;
200		break;
201	case ATTR_ENCR_TYPE_FLAGS:
202		if (len != 2) {
203			wpa_printf(MSG_DEBUG, "WPS: Invalid Encryption Type "
204				   "Flags length %u", len);
205			return -1;
206		}
207		attr->encr_type_flags = pos;
208		break;
209	case ATTR_CONN_TYPE_FLAGS:
210		if (len != 1) {
211			wpa_printf(MSG_DEBUG, "WPS: Invalid Connection Type "
212				   "Flags length %u", len);
213			return -1;
214		}
215		attr->conn_type_flags = pos;
216		break;
217	case ATTR_CONFIG_METHODS:
218		if (len != 2) {
219			wpa_printf(MSG_DEBUG, "WPS: Invalid Config Methods "
220				   "length %u", len);
221			return -1;
222		}
223		attr->config_methods = pos;
224		break;
225	case ATTR_SELECTED_REGISTRAR_CONFIG_METHODS:
226		if (len != 2) {
227			wpa_printf(MSG_DEBUG, "WPS: Invalid Selected "
228				   "Registrar Config Methods length %u", len);
229			return -1;
230		}
231		attr->sel_reg_config_methods = pos;
232		break;
233	case ATTR_PRIMARY_DEV_TYPE:
234		if (len != WPS_DEV_TYPE_LEN) {
235			wpa_printf(MSG_DEBUG, "WPS: Invalid Primary Device "
236				   "Type length %u", len);
237			return -1;
238		}
239		attr->primary_dev_type = pos;
240		break;
241	case ATTR_RF_BANDS:
242		if (len != 1) {
243			wpa_printf(MSG_DEBUG, "WPS: Invalid RF Bands length "
244				   "%u", len);
245			return -1;
246		}
247		attr->rf_bands = pos;
248		break;
249	case ATTR_ASSOC_STATE:
250		if (len != 2) {
251			wpa_printf(MSG_DEBUG, "WPS: Invalid Association State "
252				   "length %u", len);
253			return -1;
254		}
255		attr->assoc_state = pos;
256		break;
257	case ATTR_CONFIG_ERROR:
258		if (len != 2) {
259			wpa_printf(MSG_DEBUG, "WPS: Invalid Configuration "
260				   "Error length %u", len);
261			return -1;
262		}
263		attr->config_error = pos;
264		break;
265	case ATTR_DEV_PASSWORD_ID:
266		if (len != 2) {
267			wpa_printf(MSG_DEBUG, "WPS: Invalid Device Password "
268				   "ID length %u", len);
269			return -1;
270		}
271		attr->dev_password_id = pos;
272		break;
273	case ATTR_OOB_DEVICE_PASSWORD:
274		if (len < WPS_OOB_PUBKEY_HASH_LEN + 2 ||
275		    len > WPS_OOB_PUBKEY_HASH_LEN + 2 +
276		    WPS_OOB_DEVICE_PASSWORD_LEN ||
277		    (len < WPS_OOB_PUBKEY_HASH_LEN + 2 +
278		     WPS_OOB_DEVICE_PASSWORD_MIN_LEN &&
279		     WPA_GET_BE16(pos + WPS_OOB_PUBKEY_HASH_LEN) !=
280		     DEV_PW_NFC_CONNECTION_HANDOVER)) {
281			wpa_printf(MSG_DEBUG, "WPS: Invalid OOB Device "
282				   "Password length %u", len);
283			return -1;
284		}
285		attr->oob_dev_password = pos;
286		attr->oob_dev_password_len = len;
287		break;
288	case ATTR_OS_VERSION:
289		if (len != 4) {
290			wpa_printf(MSG_DEBUG, "WPS: Invalid OS Version length "
291				   "%u", len);
292			return -1;
293		}
294		attr->os_version = pos;
295		break;
296	case ATTR_WPS_STATE:
297		if (len != 1) {
298			wpa_printf(MSG_DEBUG, "WPS: Invalid Wi-Fi Protected "
299				   "Setup State length %u", len);
300			return -1;
301		}
302		attr->wps_state = pos;
303		break;
304	case ATTR_AUTHENTICATOR:
305		if (len != WPS_AUTHENTICATOR_LEN) {
306			wpa_printf(MSG_DEBUG, "WPS: Invalid Authenticator "
307				   "length %u", len);
308			return -1;
309		}
310		attr->authenticator = pos;
311		break;
312	case ATTR_R_HASH1:
313		if (len != WPS_HASH_LEN) {
314			wpa_printf(MSG_DEBUG, "WPS: Invalid R-Hash1 length %u",
315				   len);
316			return -1;
317		}
318		attr->r_hash1 = pos;
319		break;
320	case ATTR_R_HASH2:
321		if (len != WPS_HASH_LEN) {
322			wpa_printf(MSG_DEBUG, "WPS: Invalid R-Hash2 length %u",
323				   len);
324			return -1;
325		}
326		attr->r_hash2 = pos;
327		break;
328	case ATTR_E_HASH1:
329		if (len != WPS_HASH_LEN) {
330			wpa_printf(MSG_DEBUG, "WPS: Invalid E-Hash1 length %u",
331				   len);
332			return -1;
333		}
334		attr->e_hash1 = pos;
335		break;
336	case ATTR_E_HASH2:
337		if (len != WPS_HASH_LEN) {
338			wpa_printf(MSG_DEBUG, "WPS: Invalid E-Hash2 length %u",
339				   len);
340			return -1;
341		}
342		attr->e_hash2 = pos;
343		break;
344	case ATTR_R_SNONCE1:
345		if (len != WPS_SECRET_NONCE_LEN) {
346			wpa_printf(MSG_DEBUG, "WPS: Invalid R-SNonce1 length "
347				   "%u", len);
348			return -1;
349		}
350		attr->r_snonce1 = pos;
351		break;
352	case ATTR_R_SNONCE2:
353		if (len != WPS_SECRET_NONCE_LEN) {
354			wpa_printf(MSG_DEBUG, "WPS: Invalid R-SNonce2 length "
355				   "%u", len);
356			return -1;
357		}
358		attr->r_snonce2 = pos;
359		break;
360	case ATTR_E_SNONCE1:
361		if (len != WPS_SECRET_NONCE_LEN) {
362			wpa_printf(MSG_DEBUG, "WPS: Invalid E-SNonce1 length "
363				   "%u", len);
364			return -1;
365		}
366		attr->e_snonce1 = pos;
367		break;
368	case ATTR_E_SNONCE2:
369		if (len != WPS_SECRET_NONCE_LEN) {
370			wpa_printf(MSG_DEBUG, "WPS: Invalid E-SNonce2 length "
371				   "%u", len);
372			return -1;
373		}
374		attr->e_snonce2 = pos;
375		break;
376	case ATTR_KEY_WRAP_AUTH:
377		if (len != WPS_KWA_LEN) {
378			wpa_printf(MSG_DEBUG, "WPS: Invalid Key Wrap "
379				   "Authenticator length %u", len);
380			return -1;
381		}
382		attr->key_wrap_auth = pos;
383		break;
384	case ATTR_AUTH_TYPE:
385		if (len != 2) {
386			wpa_printf(MSG_DEBUG, "WPS: Invalid Authentication "
387				   "Type length %u", len);
388			return -1;
389		}
390		attr->auth_type = pos;
391		break;
392	case ATTR_ENCR_TYPE:
393		if (len != 2) {
394			wpa_printf(MSG_DEBUG, "WPS: Invalid Encryption "
395				   "Type length %u", len);
396			return -1;
397		}
398		attr->encr_type = pos;
399		break;
400	case ATTR_NETWORK_INDEX:
401		if (len != 1) {
402			wpa_printf(MSG_DEBUG, "WPS: Invalid Network Index "
403				   "length %u", len);
404			return -1;
405		}
406		attr->network_idx = pos;
407		break;
408	case ATTR_NETWORK_KEY_INDEX:
409		if (len != 1) {
410			wpa_printf(MSG_DEBUG, "WPS: Invalid Network Key Index "
411				   "length %u", len);
412			return -1;
413		}
414		attr->network_key_idx = pos;
415		break;
416	case ATTR_MAC_ADDR:
417		if (len != ETH_ALEN) {
418			wpa_printf(MSG_DEBUG, "WPS: Invalid MAC Address "
419				   "length %u", len);
420			return -1;
421		}
422		attr->mac_addr = pos;
423		break;
424	case ATTR_SELECTED_REGISTRAR:
425		if (len != 1) {
426			wpa_printf(MSG_DEBUG, "WPS: Invalid Selected Registrar"
427				   " length %u", len);
428			return -1;
429		}
430		attr->selected_registrar = pos;
431		break;
432	case ATTR_REQUEST_TYPE:
433		if (len != 1) {
434			wpa_printf(MSG_DEBUG, "WPS: Invalid Request Type "
435				   "length %u", len);
436			return -1;
437		}
438		attr->request_type = pos;
439		break;
440	case ATTR_RESPONSE_TYPE:
441		if (len != 1) {
442			wpa_printf(MSG_DEBUG, "WPS: Invalid Response Type "
443				   "length %u", len);
444			return -1;
445		}
446		attr->response_type = pos;
447		break;
448	case ATTR_MANUFACTURER:
449		attr->manufacturer = pos;
450		if (len > WPS_MANUFACTURER_MAX_LEN)
451			attr->manufacturer_len = WPS_MANUFACTURER_MAX_LEN;
452		else
453			attr->manufacturer_len = len;
454		break;
455	case ATTR_MODEL_NAME:
456		attr->model_name = pos;
457		if (len > WPS_MODEL_NAME_MAX_LEN)
458			attr->model_name_len = WPS_MODEL_NAME_MAX_LEN;
459		else
460			attr->model_name_len = len;
461		break;
462	case ATTR_MODEL_NUMBER:
463		attr->model_number = pos;
464		if (len > WPS_MODEL_NUMBER_MAX_LEN)
465			attr->model_number_len = WPS_MODEL_NUMBER_MAX_LEN;
466		else
467			attr->model_number_len = len;
468		break;
469	case ATTR_SERIAL_NUMBER:
470		attr->serial_number = pos;
471		if (len > WPS_SERIAL_NUMBER_MAX_LEN)
472			attr->serial_number_len = WPS_SERIAL_NUMBER_MAX_LEN;
473		else
474			attr->serial_number_len = len;
475		break;
476	case ATTR_DEV_NAME:
477		if (len > WPS_DEV_NAME_MAX_LEN) {
478			wpa_printf(MSG_DEBUG,
479				   "WPS: Ignore too long Device Name (len=%u)",
480				   len);
481			break;
482		}
483		attr->dev_name = pos;
484		attr->dev_name_len = len;
485		break;
486	case ATTR_PUBLIC_KEY:
487		/*
488		 * The Public Key attribute is supposed to be exactly 192 bytes
489		 * in length. Allow couple of bytes shorter one to try to
490		 * interoperate with implementations that do not use proper
491		 * zero-padding.
492		 */
493		if (len < 190 || len > 192) {
494			wpa_printf(MSG_DEBUG,
495				   "WPS: Ignore Public Key with unexpected length %u",
496				   len);
497			break;
498		}
499		attr->public_key = pos;
500		attr->public_key_len = len;
501		break;
502	case ATTR_ENCR_SETTINGS:
503		attr->encr_settings = pos;
504		attr->encr_settings_len = len;
505		break;
506	case ATTR_CRED:
507		if (attr->num_cred >= MAX_CRED_COUNT) {
508			wpa_printf(MSG_DEBUG, "WPS: Skipped Credential "
509				   "attribute (max %d credentials)",
510				   MAX_CRED_COUNT);
511			break;
512		}
513		attr->cred[attr->num_cred] = pos;
514		attr->cred_len[attr->num_cred] = len;
515		attr->num_cred++;
516		break;
517	case ATTR_SSID:
518		if (len > SSID_MAX_LEN) {
519			wpa_printf(MSG_DEBUG,
520				   "WPS: Ignore too long SSID (len=%u)", len);
521			break;
522		}
523		attr->ssid = pos;
524		attr->ssid_len = len;
525		break;
526	case ATTR_NETWORK_KEY:
527		attr->network_key = pos;
528		attr->network_key_len = len;
529		break;
530	case ATTR_AP_SETUP_LOCKED:
531		if (len != 1) {
532			wpa_printf(MSG_DEBUG, "WPS: Invalid AP Setup Locked "
533				   "length %u", len);
534			return -1;
535		}
536		attr->ap_setup_locked = pos;
537		break;
538	case ATTR_REQUESTED_DEV_TYPE:
539		if (len != WPS_DEV_TYPE_LEN) {
540			wpa_printf(MSG_DEBUG, "WPS: Invalid Requested Device "
541				   "Type length %u", len);
542			return -1;
543		}
544		if (attr->num_req_dev_type >= MAX_REQ_DEV_TYPE_COUNT) {
545			wpa_printf(MSG_DEBUG, "WPS: Skipped Requested Device "
546				   "Type attribute (max %u types)",
547				   MAX_REQ_DEV_TYPE_COUNT);
548			break;
549		}
550		attr->req_dev_type[attr->num_req_dev_type] = pos;
551		attr->num_req_dev_type++;
552		break;
553	case ATTR_SECONDARY_DEV_TYPE_LIST:
554		if (len > WPS_SEC_DEV_TYPE_MAX_LEN ||
555		    (len % WPS_DEV_TYPE_LEN) > 0) {
556			wpa_printf(MSG_DEBUG, "WPS: Invalid Secondary Device "
557				   "Type length %u", len);
558			return -1;
559		}
560		attr->sec_dev_type_list = pos;
561		attr->sec_dev_type_list_len = len;
562		break;
563	case ATTR_VENDOR_EXT:
564		if (wps_parse_vendor_ext(attr, pos, len) < 0)
565			return -1;
566		break;
567	case ATTR_AP_CHANNEL:
568		if (len != 2) {
569			wpa_printf(MSG_DEBUG, "WPS: Invalid AP Channel "
570				   "length %u", len);
571			return -1;
572		}
573		attr->ap_channel = pos;
574		break;
575	default:
576		wpa_printf(MSG_DEBUG, "WPS: Unsupported attribute type 0x%x "
577			   "len=%u", type, len);
578		break;
579	}
580
581	return 0;
582}
583
584
585int wps_parse_msg(const struct wpabuf *msg, struct wps_parse_attr *attr)
586{
587	const u8 *pos, *end;
588	u16 type, len;
589#ifdef WPS_WORKAROUNDS
590	u16 prev_type = 0;
591#endif /* WPS_WORKAROUNDS */
592
593	os_memset(attr, 0, sizeof(*attr));
594	pos = wpabuf_head(msg);
595	end = pos + wpabuf_len(msg);
596
597	while (pos < end) {
598		if (end - pos < 4) {
599			wpa_printf(MSG_DEBUG, "WPS: Invalid message - "
600				   "%lu bytes remaining",
601				   (unsigned long) (end - pos));
602			return -1;
603		}
604
605		type = WPA_GET_BE16(pos);
606		pos += 2;
607		len = WPA_GET_BE16(pos);
608		pos += 2;
609		wpa_printf(MSG_EXCESSIVE, "WPS: attr type=0x%x len=%u",
610			   type, len);
611		if (len > end - pos) {
612			wpa_printf(MSG_DEBUG, "WPS: Attribute overflow");
613			wpa_hexdump_buf(MSG_MSGDUMP, "WPS: Message data", msg);
614#ifdef WPS_WORKAROUNDS
615			/*
616			 * Some deployed APs seem to have a bug in encoding of
617			 * Network Key attribute in the Credential attribute
618			 * where they add an extra octet after the Network Key
619			 * attribute at least when open network is being
620			 * provisioned.
621			 */
622			if ((type & 0xff00) != 0x1000 &&
623			    prev_type == ATTR_NETWORK_KEY) {
624				wpa_printf(MSG_DEBUG, "WPS: Workaround - try "
625					   "to skip unexpected octet after "
626					   "Network Key");
627				pos -= 3;
628				continue;
629			}
630#endif /* WPS_WORKAROUNDS */
631			return -1;
632		}
633
634#ifdef WPS_WORKAROUNDS
635		if (type == 0 && len == 0) {
636			/*
637			 * Mac OS X 10.6 seems to be adding 0x00 padding to the
638			 * end of M1. Skip those to avoid interop issues.
639			 */
640			int i;
641			for (i = 0; i < end - pos; i++) {
642				if (pos[i])
643					break;
644			}
645			if (i == end - pos) {
646				wpa_printf(MSG_DEBUG, "WPS: Workaround - skip "
647					   "unexpected message padding");
648				break;
649			}
650		}
651#endif /* WPS_WORKAROUNDS */
652
653		if (wps_set_attr(attr, type, pos, len) < 0)
654			return -1;
655
656#ifdef WPS_WORKAROUNDS
657		prev_type = type;
658#endif /* WPS_WORKAROUNDS */
659		pos += len;
660	}
661
662	return 0;
663}
664