xref: /freebsd/contrib/wpa/src/eap_peer/eap_wsc.c (revision f05cddf9)
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 
19 struct 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 
32 static 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 
53 static 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 
62 static 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 		return -1;
82 	cred->ssid_len = len / 2;
83 
84 	pos = os_strstr(params, "new_auth=");
85 	if (pos == NULL)
86 		return -1;
87 	if (os_strncmp(pos + 9, "OPEN", 4) == 0)
88 		cred->auth_type = WPS_AUTH_OPEN;
89 	else if (os_strncmp(pos + 9, "WPAPSK", 6) == 0)
90 		cred->auth_type = WPS_AUTH_WPAPSK;
91 	else if (os_strncmp(pos + 9, "WPA2PSK", 7) == 0)
92 		cred->auth_type = WPS_AUTH_WPA2PSK;
93 	else
94 		return -1;
95 
96 	pos = os_strstr(params, "new_encr=");
97 	if (pos == NULL)
98 		return -1;
99 	if (os_strncmp(pos + 9, "NONE", 4) == 0)
100 		cred->encr_type = WPS_ENCR_NONE;
101 	else if (os_strncmp(pos + 9, "WEP", 3) == 0)
102 		cred->encr_type = WPS_ENCR_WEP;
103 	else if (os_strncmp(pos + 9, "TKIP", 4) == 0)
104 		cred->encr_type = WPS_ENCR_TKIP;
105 	else if (os_strncmp(pos + 9, "CCMP", 4) == 0)
106 		cred->encr_type = WPS_ENCR_AES;
107 	else
108 		return -1;
109 
110 	pos = os_strstr(params, "new_key=");
111 	if (pos == NULL)
112 		return 0;
113 	pos += 8;
114 	end = os_strchr(pos, ' ');
115 	if (end == NULL)
116 		len = os_strlen(pos);
117 	else
118 		len = end - pos;
119 	if ((len & 1) || len > 2 * sizeof(cred->key) ||
120 	    hexstr2bin(pos, cred->key, len / 2))
121 		return -1;
122 	cred->key_len = len / 2;
123 
124 	return 1;
125 }
126 
127 
128 static void * eap_wsc_init(struct eap_sm *sm)
129 {
130 	struct eap_wsc_data *data;
131 	const u8 *identity;
132 	size_t identity_len;
133 	int registrar;
134 	struct wps_config cfg;
135 	const char *pos;
136 	const char *phase1;
137 	struct wps_context *wps;
138 	struct wps_credential new_ap_settings;
139 	int res;
140 	u8 dev_pw[WPS_OOB_DEVICE_PASSWORD_LEN];
141 	int nfc = 0;
142 
143 	wps = sm->wps;
144 	if (wps == NULL) {
145 		wpa_printf(MSG_ERROR, "EAP-WSC: WPS context not available");
146 		return NULL;
147 	}
148 
149 	identity = eap_get_config_identity(sm, &identity_len);
150 
151 	if (identity && identity_len == WSC_ID_REGISTRAR_LEN &&
152 	    os_memcmp(identity, WSC_ID_REGISTRAR, WSC_ID_REGISTRAR_LEN) == 0)
153 		registrar = 1; /* Supplicant is Registrar */
154 	else if (identity && identity_len == WSC_ID_ENROLLEE_LEN &&
155 	    os_memcmp(identity, WSC_ID_ENROLLEE, WSC_ID_ENROLLEE_LEN) == 0)
156 		registrar = 0; /* Supplicant is Enrollee */
157 	else {
158 		wpa_hexdump_ascii(MSG_INFO, "EAP-WSC: Unexpected identity",
159 				  identity, identity_len);
160 		return NULL;
161 	}
162 
163 	data = os_zalloc(sizeof(*data));
164 	if (data == NULL)
165 		return NULL;
166 	data->state = registrar ? MESG : WAIT_START;
167 	data->registrar = registrar;
168 	data->wps_ctx = wps;
169 
170 	os_memset(&cfg, 0, sizeof(cfg));
171 	cfg.wps = wps;
172 	cfg.registrar = registrar;
173 
174 	phase1 = eap_get_config_phase1(sm);
175 	if (phase1 == NULL) {
176 		wpa_printf(MSG_INFO, "EAP-WSC: phase1 configuration data not "
177 			   "set");
178 		os_free(data);
179 		return NULL;
180 	}
181 
182 	pos = os_strstr(phase1, "pin=");
183 	if (pos) {
184 		pos += 4;
185 		cfg.pin = (const u8 *) pos;
186 		while (*pos != '\0' && *pos != ' ')
187 			pos++;
188 		cfg.pin_len = pos - (const char *) cfg.pin;
189 		if (cfg.pin_len >= WPS_OOB_DEVICE_PASSWORD_MIN_LEN * 2 &&
190 		    cfg.pin_len <= WPS_OOB_DEVICE_PASSWORD_LEN * 2 &&
191 		    hexstr2bin((const char *) cfg.pin, dev_pw,
192 			       cfg.pin_len / 2) == 0) {
193 			/* Convert OOB Device Password to binary */
194 			cfg.pin = dev_pw;
195 			cfg.pin_len /= 2;
196 		}
197 		if (cfg.pin_len == 6 && os_strncmp(pos, "nfc-pw", 6) == 0) {
198 			cfg.pin = NULL;
199 			cfg.pin_len = 0;
200 			nfc = 1;
201 		}
202 	} else {
203 		pos = os_strstr(phase1, "pbc=1");
204 		if (pos)
205 			cfg.pbc = 1;
206 	}
207 
208 	if (cfg.pin == NULL && !cfg.pbc && !nfc) {
209 		wpa_printf(MSG_INFO, "EAP-WSC: PIN or PBC not set in phase1 "
210 			   "configuration data");
211 		os_free(data);
212 		return NULL;
213 	}
214 
215 	pos = os_strstr(phase1, "dev_pw_id=");
216 	if (pos && cfg.pin)
217 		cfg.dev_pw_id = atoi(pos + 10);
218 
219 	res = eap_wsc_new_ap_settings(&new_ap_settings, phase1);
220 	if (res < 0) {
221 		os_free(data);
222 		return NULL;
223 	}
224 	if (res == 1) {
225 		wpa_printf(MSG_DEBUG, "EAP-WSC: Provide new AP settings for "
226 			   "WPS");
227 		cfg.new_ap_settings = &new_ap_settings;
228 	}
229 
230 	data->wps = wps_init(&cfg);
231 	if (data->wps == NULL) {
232 		os_free(data);
233 		return NULL;
234 	}
235 	res = eap_get_config_fragment_size(sm);
236 	if (res > 0)
237 		data->fragment_size = res;
238 	else
239 		data->fragment_size = WSC_FRAGMENT_SIZE;
240 	wpa_printf(MSG_DEBUG, "EAP-WSC: Fragment size limit %u",
241 		   (unsigned int) data->fragment_size);
242 
243 	if (registrar && cfg.pin) {
244 		wps_registrar_add_pin(data->wps_ctx->registrar, NULL, NULL,
245 				      cfg.pin, cfg.pin_len, 0);
246 	}
247 
248 	/* Use reduced client timeout for WPS to avoid long wait */
249 	if (sm->ClientTimeout > 30)
250 		sm->ClientTimeout = 30;
251 
252 	return data;
253 }
254 
255 
256 static void eap_wsc_deinit(struct eap_sm *sm, void *priv)
257 {
258 	struct eap_wsc_data *data = priv;
259 	wpabuf_free(data->in_buf);
260 	wpabuf_free(data->out_buf);
261 	wps_deinit(data->wps);
262 	os_free(data->wps_ctx->network_key);
263 	data->wps_ctx->network_key = NULL;
264 	os_free(data);
265 }
266 
267 
268 static struct wpabuf * eap_wsc_build_msg(struct eap_wsc_data *data,
269 					 struct eap_method_ret *ret, u8 id)
270 {
271 	struct wpabuf *resp;
272 	u8 flags;
273 	size_t send_len, plen;
274 
275 	ret->ignore = FALSE;
276 	wpa_printf(MSG_DEBUG, "EAP-WSC: Generating Response");
277 	ret->allowNotifications = TRUE;
278 
279 	flags = 0;
280 	send_len = wpabuf_len(data->out_buf) - data->out_used;
281 	if (2 + send_len > data->fragment_size) {
282 		send_len = data->fragment_size - 2;
283 		flags |= WSC_FLAGS_MF;
284 		if (data->out_used == 0) {
285 			flags |= WSC_FLAGS_LF;
286 			send_len -= 2;
287 		}
288 	}
289 	plen = 2 + send_len;
290 	if (flags & WSC_FLAGS_LF)
291 		plen += 2;
292 	resp = eap_msg_alloc(EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC, plen,
293 			     EAP_CODE_RESPONSE, id);
294 	if (resp == NULL)
295 		return NULL;
296 
297 	wpabuf_put_u8(resp, data->out_op_code); /* Op-Code */
298 	wpabuf_put_u8(resp, flags); /* Flags */
299 	if (flags & WSC_FLAGS_LF)
300 		wpabuf_put_be16(resp, wpabuf_len(data->out_buf));
301 
302 	wpabuf_put_data(resp, wpabuf_head_u8(data->out_buf) + data->out_used,
303 			send_len);
304 	data->out_used += send_len;
305 
306 	ret->methodState = METHOD_MAY_CONT;
307 	ret->decision = DECISION_FAIL;
308 
309 	if (data->out_used == wpabuf_len(data->out_buf)) {
310 		wpa_printf(MSG_DEBUG, "EAP-WSC: Sending out %lu bytes "
311 			   "(message sent completely)",
312 			   (unsigned long) send_len);
313 		wpabuf_free(data->out_buf);
314 		data->out_buf = NULL;
315 		data->out_used = 0;
316 		if ((data->state == FAIL && data->out_op_code == WSC_ACK) ||
317 		    data->out_op_code == WSC_NACK ||
318 		    data->out_op_code == WSC_Done) {
319 			eap_wsc_state(data, FAIL);
320 			ret->methodState = METHOD_DONE;
321 		} else
322 			eap_wsc_state(data, MESG);
323 	} else {
324 		wpa_printf(MSG_DEBUG, "EAP-WSC: Sending out %lu bytes "
325 			   "(%lu more to send)", (unsigned long) send_len,
326 			   (unsigned long) wpabuf_len(data->out_buf) -
327 			   data->out_used);
328 		eap_wsc_state(data, WAIT_FRAG_ACK);
329 	}
330 
331 	return resp;
332 }
333 
334 
335 static int eap_wsc_process_cont(struct eap_wsc_data *data,
336 				const u8 *buf, size_t len, u8 op_code)
337 {
338 	/* Process continuation of a pending message */
339 	if (op_code != data->in_op_code) {
340 		wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d in "
341 			   "fragment (expected %d)",
342 			   op_code, data->in_op_code);
343 		return -1;
344 	}
345 
346 	if (len > wpabuf_tailroom(data->in_buf)) {
347 		wpa_printf(MSG_DEBUG, "EAP-WSC: Fragment overflow");
348 		eap_wsc_state(data, FAIL);
349 		return -1;
350 	}
351 
352 	wpabuf_put_data(data->in_buf, buf, len);
353 	wpa_printf(MSG_DEBUG, "EAP-WSC: Received %lu bytes, waiting "
354 		   "for %lu bytes more", (unsigned long) len,
355 		   (unsigned long) wpabuf_tailroom(data->in_buf));
356 
357 	return 0;
358 }
359 
360 
361 static struct wpabuf * eap_wsc_process_fragment(struct eap_wsc_data *data,
362 						struct eap_method_ret *ret,
363 						u8 id, u8 flags, u8 op_code,
364 						u16 message_length,
365 						const u8 *buf, size_t len)
366 {
367 	/* Process a fragment that is not the last one of the message */
368 	if (data->in_buf == NULL && !(flags & WSC_FLAGS_LF)) {
369 		wpa_printf(MSG_DEBUG, "EAP-WSC: No Message Length field in a "
370 			   "fragmented packet");
371 		ret->ignore = TRUE;
372 		return NULL;
373 	}
374 
375 	if (data->in_buf == NULL) {
376 		/* First fragment of the message */
377 		data->in_buf = wpabuf_alloc(message_length);
378 		if (data->in_buf == NULL) {
379 			wpa_printf(MSG_DEBUG, "EAP-WSC: No memory for "
380 				   "message");
381 			ret->ignore = TRUE;
382 			return NULL;
383 		}
384 		data->in_op_code = op_code;
385 		wpabuf_put_data(data->in_buf, buf, len);
386 		wpa_printf(MSG_DEBUG, "EAP-WSC: Received %lu bytes in first "
387 			   "fragment, waiting for %lu bytes more",
388 			   (unsigned long) len,
389 			   (unsigned long) wpabuf_tailroom(data->in_buf));
390 	}
391 
392 	return eap_wsc_build_frag_ack(id, EAP_CODE_RESPONSE);
393 }
394 
395 
396 static struct wpabuf * eap_wsc_process(struct eap_sm *sm, void *priv,
397 				       struct eap_method_ret *ret,
398 				       const struct wpabuf *reqData)
399 {
400 	struct eap_wsc_data *data = priv;
401 	const u8 *start, *pos, *end;
402 	size_t len;
403 	u8 op_code, flags, id;
404 	u16 message_length = 0;
405 	enum wps_process_res res;
406 	struct wpabuf tmpbuf;
407 	struct wpabuf *r;
408 
409 	pos = eap_hdr_validate(EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC, reqData,
410 			       &len);
411 	if (pos == NULL || len < 2) {
412 		ret->ignore = TRUE;
413 		return NULL;
414 	}
415 
416 	id = eap_get_id(reqData);
417 
418 	start = pos;
419 	end = start + len;
420 
421 	op_code = *pos++;
422 	flags = *pos++;
423 	if (flags & WSC_FLAGS_LF) {
424 		if (end - pos < 2) {
425 			wpa_printf(MSG_DEBUG, "EAP-WSC: Message underflow");
426 			ret->ignore = TRUE;
427 			return NULL;
428 		}
429 		message_length = WPA_GET_BE16(pos);
430 		pos += 2;
431 
432 		if (message_length < end - pos) {
433 			wpa_printf(MSG_DEBUG, "EAP-WSC: Invalid Message "
434 				   "Length");
435 			ret->ignore = TRUE;
436 			return NULL;
437 		}
438 	}
439 
440 	wpa_printf(MSG_DEBUG, "EAP-WSC: Received packet: Op-Code %d "
441 		   "Flags 0x%x Message Length %d",
442 		   op_code, flags, message_length);
443 
444 	if (data->state == WAIT_FRAG_ACK) {
445 		if (op_code != WSC_FRAG_ACK) {
446 			wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d "
447 				   "in WAIT_FRAG_ACK state", op_code);
448 			ret->ignore = TRUE;
449 			return NULL;
450 		}
451 		wpa_printf(MSG_DEBUG, "EAP-WSC: Fragment acknowledged");
452 		eap_wsc_state(data, MESG);
453 		return eap_wsc_build_msg(data, ret, id);
454 	}
455 
456 	if (op_code != WSC_ACK && op_code != WSC_NACK && op_code != WSC_MSG &&
457 	    op_code != WSC_Done && op_code != WSC_Start) {
458 		wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d",
459 			   op_code);
460 		ret->ignore = TRUE;
461 		return NULL;
462 	}
463 
464 	if (data->state == WAIT_START) {
465 		if (op_code != WSC_Start) {
466 			wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d "
467 				   "in WAIT_START state", op_code);
468 			ret->ignore = TRUE;
469 			return NULL;
470 		}
471 		wpa_printf(MSG_DEBUG, "EAP-WSC: Received start");
472 		eap_wsc_state(data, MESG);
473 		/* Start message has empty payload, skip processing */
474 		goto send_msg;
475 	} else if (op_code == WSC_Start) {
476 		wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d",
477 			   op_code);
478 		ret->ignore = TRUE;
479 		return NULL;
480 	}
481 
482 	if (data->in_buf &&
483 	    eap_wsc_process_cont(data, pos, end - pos, op_code) < 0) {
484 		ret->ignore = TRUE;
485 		return NULL;
486 	}
487 
488 	if (flags & WSC_FLAGS_MF) {
489 		return eap_wsc_process_fragment(data, ret, id, flags, op_code,
490 						message_length, pos,
491 						end - pos);
492 	}
493 
494 	if (data->in_buf == NULL) {
495 		/* Wrap unfragmented messages as wpabuf without extra copy */
496 		wpabuf_set(&tmpbuf, pos, end - pos);
497 		data->in_buf = &tmpbuf;
498 	}
499 
500 	res = wps_process_msg(data->wps, op_code, data->in_buf);
501 	switch (res) {
502 	case WPS_DONE:
503 		wpa_printf(MSG_DEBUG, "EAP-WSC: WPS processing completed "
504 			   "successfully - wait for EAP failure");
505 		eap_wsc_state(data, FAIL);
506 		break;
507 	case WPS_CONTINUE:
508 		eap_wsc_state(data, MESG);
509 		break;
510 	case WPS_FAILURE:
511 	case WPS_PENDING:
512 		wpa_printf(MSG_DEBUG, "EAP-WSC: WPS processing failed");
513 		eap_wsc_state(data, FAIL);
514 		break;
515 	}
516 
517 	if (data->in_buf != &tmpbuf)
518 		wpabuf_free(data->in_buf);
519 	data->in_buf = NULL;
520 
521 send_msg:
522 	if (data->out_buf == NULL) {
523 		data->out_buf = wps_get_msg(data->wps, &data->out_op_code);
524 		if (data->out_buf == NULL) {
525 			wpa_printf(MSG_DEBUG, "EAP-WSC: Failed to receive "
526 				   "message from WPS");
527 			return NULL;
528 		}
529 		data->out_used = 0;
530 	}
531 
532 	eap_wsc_state(data, MESG);
533 	r = eap_wsc_build_msg(data, ret, id);
534 	if (data->state == FAIL && ret->methodState == METHOD_DONE) {
535 		/* Use reduced client timeout for WPS to avoid long wait */
536 		if (sm->ClientTimeout > 2)
537 			sm->ClientTimeout = 2;
538 	}
539 	return r;
540 }
541 
542 
543 int eap_peer_wsc_register(void)
544 {
545 	struct eap_method *eap;
546 	int ret;
547 
548 	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
549 				    EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC,
550 				    "WSC");
551 	if (eap == NULL)
552 		return -1;
553 
554 	eap->init = eap_wsc_init;
555 	eap->deinit = eap_wsc_deinit;
556 	eap->process = eap_wsc_process;
557 
558 	ret = eap_peer_method_register(eap);
559 	if (ret)
560 		eap_peer_method_free(eap);
561 	return ret;
562 }
563