1/*
2 * EAP-WSC peer for Wi-Fi Protected Setup
3 * Copyright (c) 2007-2009, 2012, 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 "uuid.h"
13#include "eap_i.h"
14#include "eap_common/eap_wsc_common.h"
15#include "wps/wps.h"
16#include "wps/wps_defs.h"
17
18
19struct eap_wsc_data {
20	enum { WAIT_START, MESG, FRAG_ACK, WAIT_FRAG_ACK, DONE, FAIL } state;
21	int registrar;
22	struct wpabuf *in_buf;
23	struct wpabuf *out_buf;
24	enum wsc_op_code in_op_code, out_op_code;
25	size_t out_used;
26	size_t fragment_size;
27	struct wps_data *wps;
28	struct wps_context *wps_ctx;
29};
30
31
32static const char * eap_wsc_state_txt(int state)
33{
34	switch (state) {
35	case WAIT_START:
36		return "WAIT_START";
37	case MESG:
38		return "MESG";
39	case FRAG_ACK:
40		return "FRAG_ACK";
41	case WAIT_FRAG_ACK:
42		return "WAIT_FRAG_ACK";
43	case DONE:
44		return "DONE";
45	case FAIL:
46		return "FAIL";
47	default:
48		return "?";
49	}
50}
51
52
53static void eap_wsc_state(struct eap_wsc_data *data, int state)
54{
55	wpa_printf(MSG_DEBUG, "EAP-WSC: %s -> %s",
56		   eap_wsc_state_txt(data->state),
57		   eap_wsc_state_txt(state));
58	data->state = state;
59}
60
61
62static int eap_wsc_new_ap_settings(struct wps_credential *cred,
63				   const char *params)
64{
65	const char *pos, *end;
66	size_t len;
67
68	os_memset(cred, 0, sizeof(*cred));
69
70	pos = os_strstr(params, "new_ssid=");
71	if (pos == NULL)
72		return 0;
73	pos += 9;
74	end = os_strchr(pos, ' ');
75	if (end == NULL)
76		len = os_strlen(pos);
77	else
78		len = end - pos;
79	if ((len & 1) || len > 2 * sizeof(cred->ssid) ||
80	    hexstr2bin(pos, cred->ssid, len / 2)) {
81		wpa_printf(MSG_DEBUG, "EAP-WSC: Invalid new_ssid");
82		return -1;
83	}
84	cred->ssid_len = len / 2;
85
86	pos = os_strstr(params, "new_auth=");
87	if (pos == NULL) {
88		wpa_printf(MSG_DEBUG, "EAP-WSC: Missing new_auth");
89		return -1;
90	}
91	if (os_strncmp(pos + 9, "OPEN", 4) == 0)
92		cred->auth_type = WPS_AUTH_OPEN;
93	else if (os_strncmp(pos + 9, "WPAPSK", 6) == 0)
94		cred->auth_type = WPS_AUTH_WPAPSK;
95	else if (os_strncmp(pos + 9, "WPA2PSK", 7) == 0)
96		cred->auth_type = WPS_AUTH_WPA2PSK;
97	else {
98		wpa_printf(MSG_DEBUG, "EAP-WSC: Unknown new_auth");
99		return -1;
100	}
101
102	pos = os_strstr(params, "new_encr=");
103	if (pos == NULL) {
104		wpa_printf(MSG_DEBUG, "EAP-WSC: Missing new_encr");
105		return -1;
106	}
107	if (os_strncmp(pos + 9, "NONE", 4) == 0)
108		cred->encr_type = WPS_ENCR_NONE;
109#ifdef CONFIG_TESTING_OPTIONS
110	else if (os_strncmp(pos + 9, "WEP", 3) == 0)
111		cred->encr_type = WPS_ENCR_WEP;
112#endif /* CONFIG_TESTING_OPTIONS */
113	else if (os_strncmp(pos + 9, "TKIP", 4) == 0)
114		cred->encr_type = WPS_ENCR_TKIP;
115	else if (os_strncmp(pos + 9, "CCMP", 4) == 0)
116		cred->encr_type = WPS_ENCR_AES;
117	else {
118		wpa_printf(MSG_DEBUG, "EAP-WSC: Unknown new_encr");
119		return -1;
120	}
121
122	pos = os_strstr(params, "new_key=");
123	if (pos == NULL)
124		return 0;
125	pos += 8;
126	end = os_strchr(pos, ' ');
127	if (end == NULL)
128		len = os_strlen(pos);
129	else
130		len = end - pos;
131	if ((len & 1) || len > 2 * sizeof(cred->key) ||
132	    hexstr2bin(pos, cred->key, len / 2)) {
133		wpa_printf(MSG_DEBUG, "EAP-WSC: Invalid new_key");
134		return -1;
135	}
136	cred->key_len = len / 2;
137
138	return 1;
139}
140
141
142static void * eap_wsc_init(struct eap_sm *sm)
143{
144	struct eap_wsc_data *data;
145	const u8 *identity;
146	size_t identity_len;
147	int registrar;
148	struct wps_config cfg;
149	const char *pos, *end;
150	const char *phase1;
151	struct wps_context *wps;
152	struct wps_credential new_ap_settings;
153	int res;
154	int nfc = 0;
155	u8 pkhash[WPS_OOB_PUBKEY_HASH_LEN];
156
157	wps = sm->wps;
158	if (wps == NULL) {
159		wpa_printf(MSG_ERROR, "EAP-WSC: WPS context not available");
160		return NULL;
161	}
162
163	identity = eap_get_config_identity(sm, &identity_len);
164
165	if (identity && identity_len == WSC_ID_REGISTRAR_LEN &&
166	    os_memcmp(identity, WSC_ID_REGISTRAR, WSC_ID_REGISTRAR_LEN) == 0)
167		registrar = 1; /* Supplicant is Registrar */
168	else if (identity && identity_len == WSC_ID_ENROLLEE_LEN &&
169	    os_memcmp(identity, WSC_ID_ENROLLEE, WSC_ID_ENROLLEE_LEN) == 0)
170		registrar = 0; /* Supplicant is Enrollee */
171	else {
172		wpa_hexdump_ascii(MSG_INFO, "EAP-WSC: Unexpected identity",
173				  identity, identity_len);
174		return NULL;
175	}
176
177	data = os_zalloc(sizeof(*data));
178	if (data == NULL)
179		return NULL;
180	data->state = registrar ? MESG : WAIT_START;
181	data->registrar = registrar;
182	data->wps_ctx = wps;
183
184	os_memset(&cfg, 0, sizeof(cfg));
185	cfg.wps = wps;
186	cfg.registrar = registrar;
187
188	phase1 = eap_get_config_phase1(sm);
189	if (phase1 == NULL) {
190		wpa_printf(MSG_INFO, "EAP-WSC: phase1 configuration data not "
191			   "set");
192		os_free(data);
193		return NULL;
194	}
195
196	pos = os_strstr(phase1, "pin=");
197	if (pos) {
198		pos += 4;
199		cfg.pin = (const u8 *) pos;
200		while (*pos != '\0' && *pos != ' ')
201			pos++;
202		cfg.pin_len = pos - (const char *) cfg.pin;
203		if (cfg.pin_len == 6 &&
204		    os_strncmp((const char *) cfg.pin, "nfc-pw", 6) == 0) {
205			cfg.pin = NULL;
206			cfg.pin_len = 0;
207			nfc = 1;
208		}
209	} else {
210		pos = os_strstr(phase1, "pbc=1");
211		if (pos)
212			cfg.pbc = 1;
213	}
214
215	pos = os_strstr(phase1, "dev_pw_id=");
216	if (pos) {
217		u16 id = atoi(pos + 10);
218		if (id == DEV_PW_NFC_CONNECTION_HANDOVER)
219			nfc = 1;
220		if (cfg.pin || id == DEV_PW_NFC_CONNECTION_HANDOVER)
221			cfg.dev_pw_id = id;
222	}
223
224	if (cfg.pin == NULL && !cfg.pbc && !nfc) {
225		wpa_printf(MSG_INFO, "EAP-WSC: PIN or PBC not set in phase1 "
226			   "configuration data");
227		os_free(data);
228		return NULL;
229	}
230
231	pos = os_strstr(phase1, " pkhash=");
232	if (pos) {
233		size_t len;
234		pos += 8;
235		end = os_strchr(pos, ' ');
236		if (end)
237			len = end - pos;
238		else
239			len = os_strlen(pos);
240		if (len != 2 * WPS_OOB_PUBKEY_HASH_LEN ||
241		    hexstr2bin(pos, pkhash, WPS_OOB_PUBKEY_HASH_LEN)) {
242			wpa_printf(MSG_INFO, "EAP-WSC: Invalid pkhash");
243			os_free(data);
244			return NULL;
245		}
246		cfg.peer_pubkey_hash = pkhash;
247	}
248
249	res = eap_wsc_new_ap_settings(&new_ap_settings, phase1);
250	if (res < 0) {
251		os_free(data);
252		wpa_printf(MSG_DEBUG, "EAP-WSC: Failed to parse new AP "
253			   "settings");
254		return NULL;
255	}
256	if (res == 1) {
257		wpa_printf(MSG_DEBUG, "EAP-WSC: Provide new AP settings for "
258			   "WPS");
259		cfg.new_ap_settings = &new_ap_settings;
260	}
261
262	data->wps = wps_init(&cfg);
263	if (data->wps == NULL) {
264		os_free(data);
265		wpa_printf(MSG_DEBUG, "EAP-WSC: wps_init failed");
266		return NULL;
267	}
268	res = eap_get_config_fragment_size(sm);
269	if (res > 0)
270		data->fragment_size = res;
271	else
272		data->fragment_size = WSC_FRAGMENT_SIZE;
273	wpa_printf(MSG_DEBUG, "EAP-WSC: Fragment size limit %u",
274		   (unsigned int) data->fragment_size);
275
276	if (registrar && cfg.pin) {
277		wps_registrar_add_pin(data->wps_ctx->registrar, NULL, NULL,
278				      cfg.pin, cfg.pin_len, 0);
279	}
280
281	/* Use reduced client timeout for WPS to avoid long wait */
282	if (sm->ClientTimeout > 30)
283		sm->ClientTimeout = 30;
284
285	return data;
286}
287
288
289static void eap_wsc_deinit(struct eap_sm *sm, void *priv)
290{
291	struct eap_wsc_data *data = priv;
292	wpabuf_free(data->in_buf);
293	wpabuf_free(data->out_buf);
294	wps_deinit(data->wps);
295	os_free(data->wps_ctx->network_key);
296	data->wps_ctx->network_key = NULL;
297	os_free(data);
298}
299
300
301static struct wpabuf * eap_wsc_build_msg(struct eap_wsc_data *data,
302					 struct eap_method_ret *ret, u8 id)
303{
304	struct wpabuf *resp;
305	u8 flags;
306	size_t send_len, plen;
307
308	ret->ignore = FALSE;
309	wpa_printf(MSG_DEBUG, "EAP-WSC: Generating Response");
310	ret->allowNotifications = TRUE;
311
312	flags = 0;
313	send_len = wpabuf_len(data->out_buf) - data->out_used;
314	if (2 + send_len > data->fragment_size) {
315		send_len = data->fragment_size - 2;
316		flags |= WSC_FLAGS_MF;
317		if (data->out_used == 0) {
318			flags |= WSC_FLAGS_LF;
319			send_len -= 2;
320		}
321	}
322	plen = 2 + send_len;
323	if (flags & WSC_FLAGS_LF)
324		plen += 2;
325	resp = eap_msg_alloc(EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC, plen,
326			     EAP_CODE_RESPONSE, id);
327	if (resp == NULL)
328		return NULL;
329
330	wpabuf_put_u8(resp, data->out_op_code); /* Op-Code */
331	wpabuf_put_u8(resp, flags); /* Flags */
332	if (flags & WSC_FLAGS_LF)
333		wpabuf_put_be16(resp, wpabuf_len(data->out_buf));
334
335	wpabuf_put_data(resp, wpabuf_head_u8(data->out_buf) + data->out_used,
336			send_len);
337	data->out_used += send_len;
338
339	ret->methodState = METHOD_MAY_CONT;
340	ret->decision = DECISION_FAIL;
341
342	if (data->out_used == wpabuf_len(data->out_buf)) {
343		wpa_printf(MSG_DEBUG, "EAP-WSC: Sending out %lu bytes "
344			   "(message sent completely)",
345			   (unsigned long) send_len);
346		wpabuf_free(data->out_buf);
347		data->out_buf = NULL;
348		data->out_used = 0;
349		if ((data->state == FAIL && data->out_op_code == WSC_ACK) ||
350		    data->out_op_code == WSC_NACK ||
351		    data->out_op_code == WSC_Done) {
352			eap_wsc_state(data, FAIL);
353			ret->methodState = METHOD_DONE;
354		} else
355			eap_wsc_state(data, MESG);
356	} else {
357		wpa_printf(MSG_DEBUG, "EAP-WSC: Sending out %lu bytes "
358			   "(%lu more to send)", (unsigned long) send_len,
359			   (unsigned long) wpabuf_len(data->out_buf) -
360			   data->out_used);
361		eap_wsc_state(data, WAIT_FRAG_ACK);
362	}
363
364	return resp;
365}
366
367
368static int eap_wsc_process_cont(struct eap_wsc_data *data,
369				const u8 *buf, size_t len, u8 op_code)
370{
371	/* Process continuation of a pending message */
372	if (op_code != data->in_op_code) {
373		wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d in "
374			   "fragment (expected %d)",
375			   op_code, data->in_op_code);
376		return -1;
377	}
378
379	if (len > wpabuf_tailroom(data->in_buf)) {
380		wpa_printf(MSG_DEBUG, "EAP-WSC: Fragment overflow");
381		eap_wsc_state(data, FAIL);
382		return -1;
383	}
384
385	wpabuf_put_data(data->in_buf, buf, len);
386	wpa_printf(MSG_DEBUG, "EAP-WSC: Received %lu bytes, waiting "
387		   "for %lu bytes more", (unsigned long) len,
388		   (unsigned long) wpabuf_tailroom(data->in_buf));
389
390	return 0;
391}
392
393
394static struct wpabuf * eap_wsc_process_fragment(struct eap_wsc_data *data,
395						struct eap_method_ret *ret,
396						u8 id, u8 flags, u8 op_code,
397						u16 message_length,
398						const u8 *buf, size_t len)
399{
400	/* Process a fragment that is not the last one of the message */
401	if (data->in_buf == NULL && !(flags & WSC_FLAGS_LF)) {
402		wpa_printf(MSG_DEBUG, "EAP-WSC: No Message Length field in a "
403			   "fragmented packet");
404		ret->ignore = TRUE;
405		return NULL;
406	}
407
408	if (data->in_buf == NULL) {
409		/* First fragment of the message */
410		data->in_buf = wpabuf_alloc(message_length);
411		if (data->in_buf == NULL) {
412			wpa_printf(MSG_DEBUG, "EAP-WSC: No memory for "
413				   "message");
414			ret->ignore = TRUE;
415			return NULL;
416		}
417		data->in_op_code = op_code;
418		wpabuf_put_data(data->in_buf, buf, len);
419		wpa_printf(MSG_DEBUG, "EAP-WSC: Received %lu bytes in first "
420			   "fragment, waiting for %lu bytes more",
421			   (unsigned long) len,
422			   (unsigned long) wpabuf_tailroom(data->in_buf));
423	}
424
425	return eap_wsc_build_frag_ack(id, EAP_CODE_RESPONSE);
426}
427
428
429static struct wpabuf * eap_wsc_process(struct eap_sm *sm, void *priv,
430				       struct eap_method_ret *ret,
431				       const struct wpabuf *reqData)
432{
433	struct eap_wsc_data *data = priv;
434	const u8 *start, *pos, *end;
435	size_t len;
436	u8 op_code, flags, id;
437	u16 message_length = 0;
438	enum wps_process_res res;
439	struct wpabuf tmpbuf;
440	struct wpabuf *r;
441
442	pos = eap_hdr_validate(EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC, reqData,
443			       &len);
444	if (pos == NULL || len < 2) {
445		ret->ignore = TRUE;
446		return NULL;
447	}
448
449	id = eap_get_id(reqData);
450
451	start = pos;
452	end = start + len;
453
454	op_code = *pos++;
455	flags = *pos++;
456	if (flags & WSC_FLAGS_LF) {
457		if (end - pos < 2) {
458			wpa_printf(MSG_DEBUG, "EAP-WSC: Message underflow");
459			ret->ignore = TRUE;
460			return NULL;
461		}
462		message_length = WPA_GET_BE16(pos);
463		pos += 2;
464
465		if (message_length < end - pos) {
466			wpa_printf(MSG_DEBUG, "EAP-WSC: Invalid Message "
467				   "Length");
468			ret->ignore = TRUE;
469			return NULL;
470		}
471	}
472
473	wpa_printf(MSG_DEBUG, "EAP-WSC: Received packet: Op-Code %d "
474		   "Flags 0x%x Message Length %d",
475		   op_code, flags, message_length);
476
477	if (data->state == WAIT_FRAG_ACK) {
478		if (op_code != WSC_FRAG_ACK) {
479			wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d "
480				   "in WAIT_FRAG_ACK state", op_code);
481			ret->ignore = TRUE;
482			return NULL;
483		}
484		wpa_printf(MSG_DEBUG, "EAP-WSC: Fragment acknowledged");
485		eap_wsc_state(data, MESG);
486		return eap_wsc_build_msg(data, ret, id);
487	}
488
489	if (op_code != WSC_ACK && op_code != WSC_NACK && op_code != WSC_MSG &&
490	    op_code != WSC_Done && op_code != WSC_Start) {
491		wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d",
492			   op_code);
493		ret->ignore = TRUE;
494		return NULL;
495	}
496
497	if (data->state == WAIT_START) {
498		if (op_code != WSC_Start) {
499			wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d "
500				   "in WAIT_START state", op_code);
501			ret->ignore = TRUE;
502			return NULL;
503		}
504		wpa_printf(MSG_DEBUG, "EAP-WSC: Received start");
505		eap_wsc_state(data, MESG);
506		/* Start message has empty payload, skip processing */
507		goto send_msg;
508	} else if (op_code == WSC_Start) {
509		wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d",
510			   op_code);
511		ret->ignore = TRUE;
512		return NULL;
513	}
514
515	if (data->in_buf &&
516	    eap_wsc_process_cont(data, pos, end - pos, op_code) < 0) {
517		ret->ignore = TRUE;
518		return NULL;
519	}
520
521	if (flags & WSC_FLAGS_MF) {
522		return eap_wsc_process_fragment(data, ret, id, flags, op_code,
523						message_length, pos,
524						end - pos);
525	}
526
527	if (data->in_buf == NULL) {
528		/* Wrap unfragmented messages as wpabuf without extra copy */
529		wpabuf_set(&tmpbuf, pos, end - pos);
530		data->in_buf = &tmpbuf;
531	}
532
533	res = wps_process_msg(data->wps, op_code, data->in_buf);
534	switch (res) {
535	case WPS_DONE:
536		wpa_printf(MSG_DEBUG, "EAP-WSC: WPS processing completed "
537			   "successfully - wait for EAP failure");
538		eap_wsc_state(data, FAIL);
539		break;
540	case WPS_CONTINUE:
541		eap_wsc_state(data, MESG);
542		break;
543	case WPS_FAILURE:
544	case WPS_PENDING:
545		wpa_printf(MSG_DEBUG, "EAP-WSC: WPS processing failed");
546		eap_wsc_state(data, FAIL);
547		break;
548	}
549
550	if (data->in_buf != &tmpbuf)
551		wpabuf_free(data->in_buf);
552	data->in_buf = NULL;
553
554send_msg:
555	if (data->out_buf == NULL) {
556		data->out_buf = wps_get_msg(data->wps, &data->out_op_code);
557		if (data->out_buf == NULL) {
558			wpa_printf(MSG_DEBUG, "EAP-WSC: Failed to receive "
559				   "message from WPS");
560			return NULL;
561		}
562		data->out_used = 0;
563	}
564
565	eap_wsc_state(data, MESG);
566	r = eap_wsc_build_msg(data, ret, id);
567	if (data->state == FAIL && ret->methodState == METHOD_DONE) {
568		/* Use reduced client timeout for WPS to avoid long wait */
569		if (sm->ClientTimeout > 2)
570			sm->ClientTimeout = 2;
571	}
572	return r;
573}
574
575
576int eap_peer_wsc_register(void)
577{
578	struct eap_method *eap;
579	int ret;
580
581	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
582				    EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC,
583				    "WSC");
584	if (eap == NULL)
585		return -1;
586
587	eap->init = eap_wsc_init;
588	eap->deinit = eap_wsc_deinit;
589	eap->process = eap_wsc_process;
590
591	ret = eap_peer_method_register(eap);
592	if (ret)
593		eap_peer_method_free(eap);
594	return ret;
595}
596