xref: /freebsd/contrib/wpa/src/eap_peer/eap_wsc.c (revision 884a2a699669ec61e2366e3e358342dbc94be24a)
1 /*
2  * EAP-WSC peer for Wi-Fi Protected Setup
3  * Copyright (c) 2007-2009, Jouni Malinen <j@w1.fi>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  *
9  * Alternatively, this software may be distributed under the terms of BSD
10  * license.
11  *
12  * See README and COPYING for more details.
13  */
14 
15 #include "includes.h"
16 
17 #include "common.h"
18 #include "uuid.h"
19 #include "eap_i.h"
20 #include "eap_common/eap_wsc_common.h"
21 #include "wps/wps.h"
22 #include "wps/wps_defs.h"
23 
24 
25 struct eap_wsc_data {
26 	enum { WAIT_START, MESG, FRAG_ACK, WAIT_FRAG_ACK, DONE, FAIL } state;
27 	int registrar;
28 	struct wpabuf *in_buf;
29 	struct wpabuf *out_buf;
30 	enum wsc_op_code in_op_code, out_op_code;
31 	size_t out_used;
32 	size_t fragment_size;
33 	struct wps_data *wps;
34 	struct wps_context *wps_ctx;
35 };
36 
37 
38 static const char * eap_wsc_state_txt(int state)
39 {
40 	switch (state) {
41 	case WAIT_START:
42 		return "WAIT_START";
43 	case MESG:
44 		return "MESG";
45 	case FRAG_ACK:
46 		return "FRAG_ACK";
47 	case WAIT_FRAG_ACK:
48 		return "WAIT_FRAG_ACK";
49 	case DONE:
50 		return "DONE";
51 	case FAIL:
52 		return "FAIL";
53 	default:
54 		return "?";
55 	}
56 }
57 
58 
59 static void eap_wsc_state(struct eap_wsc_data *data, int state)
60 {
61 	wpa_printf(MSG_DEBUG, "EAP-WSC: %s -> %s",
62 		   eap_wsc_state_txt(data->state),
63 		   eap_wsc_state_txt(state));
64 	data->state = state;
65 }
66 
67 
68 static int eap_wsc_new_ap_settings(struct wps_credential *cred,
69 				   const char *params)
70 {
71 	const char *pos, *end;
72 	size_t len;
73 
74 	os_memset(cred, 0, sizeof(*cred));
75 
76 	pos = os_strstr(params, "new_ssid=");
77 	if (pos == NULL)
78 		return 0;
79 	pos += 9;
80 	end = os_strchr(pos, ' ');
81 	if (end == NULL)
82 		len = os_strlen(pos);
83 	else
84 		len = end - pos;
85 	if ((len & 1) || len > 2 * sizeof(cred->ssid) ||
86 	    hexstr2bin(pos, cred->ssid, len / 2))
87 		return -1;
88 	cred->ssid_len = len / 2;
89 
90 	pos = os_strstr(params, "new_auth=");
91 	if (pos == NULL)
92 		return -1;
93 	if (os_strncmp(pos + 9, "OPEN", 4) == 0)
94 		cred->auth_type = WPS_AUTH_OPEN;
95 	else if (os_strncmp(pos + 9, "WPAPSK", 6) == 0)
96 		cred->auth_type = WPS_AUTH_WPAPSK;
97 	else if (os_strncmp(pos + 9, "WPA2PSK", 7) == 0)
98 		cred->auth_type = WPS_AUTH_WPA2PSK;
99 	else
100 		return -1;
101 
102 	pos = os_strstr(params, "new_encr=");
103 	if (pos == NULL)
104 		return -1;
105 	if (os_strncmp(pos + 9, "NONE", 4) == 0)
106 		cred->encr_type = WPS_ENCR_NONE;
107 	else if (os_strncmp(pos + 9, "WEP", 3) == 0)
108 		cred->encr_type = WPS_ENCR_WEP;
109 	else if (os_strncmp(pos + 9, "TKIP", 4) == 0)
110 		cred->encr_type = WPS_ENCR_TKIP;
111 	else if (os_strncmp(pos + 9, "CCMP", 4) == 0)
112 		cred->encr_type = WPS_ENCR_AES;
113 	else
114 		return -1;
115 
116 	pos = os_strstr(params, "new_key=");
117 	if (pos == NULL)
118 		return 0;
119 	pos += 8;
120 	end = os_strchr(pos, ' ');
121 	if (end == NULL)
122 		len = os_strlen(pos);
123 	else
124 		len = end - pos;
125 	if ((len & 1) || len > 2 * sizeof(cred->key) ||
126 	    hexstr2bin(pos, cred->key, len / 2))
127 		return -1;
128 	cred->key_len = len / 2;
129 
130 	return 1;
131 }
132 
133 
134 static void * eap_wsc_init(struct eap_sm *sm)
135 {
136 	struct eap_wsc_data *data;
137 	const u8 *identity;
138 	size_t identity_len;
139 	int registrar;
140 	struct wps_config cfg;
141 	const char *pos;
142 	const char *phase1;
143 	struct wps_context *wps;
144 	struct wps_credential new_ap_settings;
145 	int res;
146 
147 	wps = sm->wps;
148 	if (wps == NULL) {
149 		wpa_printf(MSG_ERROR, "EAP-WSC: WPS context not available");
150 		return NULL;
151 	}
152 
153 	identity = eap_get_config_identity(sm, &identity_len);
154 
155 	if (identity && identity_len == WSC_ID_REGISTRAR_LEN &&
156 	    os_memcmp(identity, WSC_ID_REGISTRAR, WSC_ID_REGISTRAR_LEN) == 0)
157 		registrar = 1; /* Supplicant is Registrar */
158 	else if (identity && identity_len == WSC_ID_ENROLLEE_LEN &&
159 	    os_memcmp(identity, WSC_ID_ENROLLEE, WSC_ID_ENROLLEE_LEN) == 0)
160 		registrar = 0; /* Supplicant is Enrollee */
161 	else {
162 		wpa_hexdump_ascii(MSG_INFO, "EAP-WSC: Unexpected identity",
163 				  identity, identity_len);
164 		return NULL;
165 	}
166 
167 	data = os_zalloc(sizeof(*data));
168 	if (data == NULL)
169 		return NULL;
170 	data->state = registrar ? MESG : WAIT_START;
171 	data->registrar = registrar;
172 	data->wps_ctx = wps;
173 
174 	os_memset(&cfg, 0, sizeof(cfg));
175 	cfg.wps = wps;
176 	cfg.registrar = registrar;
177 
178 	phase1 = eap_get_config_phase1(sm);
179 	if (phase1 == NULL) {
180 		wpa_printf(MSG_INFO, "EAP-WSC: phase1 configuration data not "
181 			   "set");
182 		os_free(data);
183 		return NULL;
184 	}
185 
186 	pos = os_strstr(phase1, "pin=");
187 	if (pos) {
188 		pos += 4;
189 		cfg.pin = (const u8 *) pos;
190 		while (*pos != '\0' && *pos != ' ')
191 			pos++;
192 		cfg.pin_len = pos - (const char *) cfg.pin;
193 	} else {
194 		pos = os_strstr(phase1, "pbc=1");
195 		if (pos)
196 			cfg.pbc = 1;
197 	}
198 
199 	if (cfg.pin == NULL && !cfg.pbc) {
200 		wpa_printf(MSG_INFO, "EAP-WSC: PIN or PBC not set in phase1 "
201 			   "configuration data");
202 		os_free(data);
203 		return NULL;
204 	}
205 
206 	res = eap_wsc_new_ap_settings(&new_ap_settings, phase1);
207 	if (res < 0) {
208 		os_free(data);
209 		return NULL;
210 	}
211 	if (res == 1) {
212 		wpa_printf(MSG_DEBUG, "EAP-WSC: Provide new AP settings for "
213 			   "WPS");
214 		cfg.new_ap_settings = &new_ap_settings;
215 	}
216 
217 	data->wps = wps_init(&cfg);
218 	if (data->wps == NULL) {
219 		os_free(data);
220 		return NULL;
221 	}
222 	data->fragment_size = WSC_FRAGMENT_SIZE;
223 
224 	if (registrar && cfg.pin) {
225 		wps_registrar_add_pin(data->wps_ctx->registrar, NULL,
226 				      cfg.pin, cfg.pin_len, 0);
227 	}
228 
229 	/* Use reduced client timeout for WPS to avoid long wait */
230 	if (sm->ClientTimeout > 30)
231 		sm->ClientTimeout = 30;
232 
233 	return data;
234 }
235 
236 
237 static void eap_wsc_deinit(struct eap_sm *sm, void *priv)
238 {
239 	struct eap_wsc_data *data = priv;
240 	wpabuf_free(data->in_buf);
241 	wpabuf_free(data->out_buf);
242 	wps_deinit(data->wps);
243 	os_free(data->wps_ctx->network_key);
244 	data->wps_ctx->network_key = NULL;
245 	os_free(data);
246 }
247 
248 
249 static struct wpabuf * eap_wsc_build_msg(struct eap_wsc_data *data,
250 					 struct eap_method_ret *ret, u8 id)
251 {
252 	struct wpabuf *resp;
253 	u8 flags;
254 	size_t send_len, plen;
255 
256 	ret->ignore = FALSE;
257 	wpa_printf(MSG_DEBUG, "EAP-WSC: Generating Response");
258 	ret->allowNotifications = TRUE;
259 
260 	flags = 0;
261 	send_len = wpabuf_len(data->out_buf) - data->out_used;
262 	if (2 + send_len > data->fragment_size) {
263 		send_len = data->fragment_size - 2;
264 		flags |= WSC_FLAGS_MF;
265 		if (data->out_used == 0) {
266 			flags |= WSC_FLAGS_LF;
267 			send_len -= 2;
268 		}
269 	}
270 	plen = 2 + send_len;
271 	if (flags & WSC_FLAGS_LF)
272 		plen += 2;
273 	resp = eap_msg_alloc(EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC, plen,
274 			     EAP_CODE_RESPONSE, id);
275 	if (resp == NULL)
276 		return NULL;
277 
278 	wpabuf_put_u8(resp, data->out_op_code); /* Op-Code */
279 	wpabuf_put_u8(resp, flags); /* Flags */
280 	if (flags & WSC_FLAGS_LF)
281 		wpabuf_put_be16(resp, wpabuf_len(data->out_buf));
282 
283 	wpabuf_put_data(resp, wpabuf_head_u8(data->out_buf) + data->out_used,
284 			send_len);
285 	data->out_used += send_len;
286 
287 	ret->methodState = METHOD_MAY_CONT;
288 	ret->decision = DECISION_FAIL;
289 
290 	if (data->out_used == wpabuf_len(data->out_buf)) {
291 		wpa_printf(MSG_DEBUG, "EAP-WSC: Sending out %lu bytes "
292 			   "(message sent completely)",
293 			   (unsigned long) send_len);
294 		wpabuf_free(data->out_buf);
295 		data->out_buf = NULL;
296 		data->out_used = 0;
297 		if ((data->state == FAIL && data->out_op_code == WSC_ACK) ||
298 		    data->out_op_code == WSC_NACK ||
299 		    data->out_op_code == WSC_Done) {
300 			eap_wsc_state(data, FAIL);
301 			ret->methodState = METHOD_DONE;
302 		} else
303 			eap_wsc_state(data, MESG);
304 	} else {
305 		wpa_printf(MSG_DEBUG, "EAP-WSC: Sending out %lu bytes "
306 			   "(%lu more to send)", (unsigned long) send_len,
307 			   (unsigned long) wpabuf_len(data->out_buf) -
308 			   data->out_used);
309 		eap_wsc_state(data, WAIT_FRAG_ACK);
310 	}
311 
312 	return resp;
313 }
314 
315 
316 static int eap_wsc_process_cont(struct eap_wsc_data *data,
317 				const u8 *buf, size_t len, u8 op_code)
318 {
319 	/* Process continuation of a pending message */
320 	if (op_code != data->in_op_code) {
321 		wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d in "
322 			   "fragment (expected %d)",
323 			   op_code, data->in_op_code);
324 		return -1;
325 	}
326 
327 	if (len > wpabuf_tailroom(data->in_buf)) {
328 		wpa_printf(MSG_DEBUG, "EAP-WSC: Fragment overflow");
329 		eap_wsc_state(data, FAIL);
330 		return -1;
331 	}
332 
333 	wpabuf_put_data(data->in_buf, buf, len);
334 	wpa_printf(MSG_DEBUG, "EAP-WSC: Received %lu bytes, waiting "
335 		   "for %lu bytes more", (unsigned long) len,
336 		   (unsigned long) wpabuf_tailroom(data->in_buf));
337 
338 	return 0;
339 }
340 
341 
342 static struct wpabuf * eap_wsc_process_fragment(struct eap_wsc_data *data,
343 						struct eap_method_ret *ret,
344 						u8 id, u8 flags, u8 op_code,
345 						u16 message_length,
346 						const u8 *buf, size_t len)
347 {
348 	/* Process a fragment that is not the last one of the message */
349 	if (data->in_buf == NULL && !(flags & WSC_FLAGS_LF)) {
350 		wpa_printf(MSG_DEBUG, "EAP-WSC: No Message Length field in a "
351 			   "fragmented packet");
352 		ret->ignore = TRUE;
353 		return NULL;
354 	}
355 
356 	if (data->in_buf == NULL) {
357 		/* First fragment of the message */
358 		data->in_buf = wpabuf_alloc(message_length);
359 		if (data->in_buf == NULL) {
360 			wpa_printf(MSG_DEBUG, "EAP-WSC: No memory for "
361 				   "message");
362 			ret->ignore = TRUE;
363 			return NULL;
364 		}
365 		data->in_op_code = op_code;
366 		wpabuf_put_data(data->in_buf, buf, len);
367 		wpa_printf(MSG_DEBUG, "EAP-WSC: Received %lu bytes in first "
368 			   "fragment, waiting for %lu bytes more",
369 			   (unsigned long) len,
370 			   (unsigned long) wpabuf_tailroom(data->in_buf));
371 	}
372 
373 	return eap_wsc_build_frag_ack(id, EAP_CODE_RESPONSE);
374 }
375 
376 
377 static struct wpabuf * eap_wsc_process(struct eap_sm *sm, void *priv,
378 				       struct eap_method_ret *ret,
379 				       const struct wpabuf *reqData)
380 {
381 	struct eap_wsc_data *data = priv;
382 	const u8 *start, *pos, *end;
383 	size_t len;
384 	u8 op_code, flags, id;
385 	u16 message_length = 0;
386 	enum wps_process_res res;
387 	struct wpabuf tmpbuf;
388 	struct wpabuf *r;
389 
390 	pos = eap_hdr_validate(EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC, reqData,
391 			       &len);
392 	if (pos == NULL || len < 2) {
393 		ret->ignore = TRUE;
394 		return NULL;
395 	}
396 
397 	id = eap_get_id(reqData);
398 
399 	start = pos;
400 	end = start + len;
401 
402 	op_code = *pos++;
403 	flags = *pos++;
404 	if (flags & WSC_FLAGS_LF) {
405 		if (end - pos < 2) {
406 			wpa_printf(MSG_DEBUG, "EAP-WSC: Message underflow");
407 			ret->ignore = TRUE;
408 			return NULL;
409 		}
410 		message_length = WPA_GET_BE16(pos);
411 		pos += 2;
412 
413 		if (message_length < end - pos) {
414 			wpa_printf(MSG_DEBUG, "EAP-WSC: Invalid Message "
415 				   "Length");
416 			ret->ignore = TRUE;
417 			return NULL;
418 		}
419 	}
420 
421 	wpa_printf(MSG_DEBUG, "EAP-WSC: Received packet: Op-Code %d "
422 		   "Flags 0x%x Message Length %d",
423 		   op_code, flags, message_length);
424 
425 	if (data->state == WAIT_FRAG_ACK) {
426 		if (op_code != WSC_FRAG_ACK) {
427 			wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d "
428 				   "in WAIT_FRAG_ACK state", op_code);
429 			ret->ignore = TRUE;
430 			return NULL;
431 		}
432 		wpa_printf(MSG_DEBUG, "EAP-WSC: Fragment acknowledged");
433 		eap_wsc_state(data, MESG);
434 		return eap_wsc_build_msg(data, ret, id);
435 	}
436 
437 	if (op_code != WSC_ACK && op_code != WSC_NACK && op_code != WSC_MSG &&
438 	    op_code != WSC_Done && op_code != WSC_Start) {
439 		wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d",
440 			   op_code);
441 		ret->ignore = TRUE;
442 		return NULL;
443 	}
444 
445 	if (data->state == WAIT_START) {
446 		if (op_code != WSC_Start) {
447 			wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d "
448 				   "in WAIT_START state", op_code);
449 			ret->ignore = TRUE;
450 			return NULL;
451 		}
452 		wpa_printf(MSG_DEBUG, "EAP-WSC: Received start");
453 		eap_wsc_state(data, MESG);
454 		/* Start message has empty payload, skip processing */
455 		goto send_msg;
456 	} else if (op_code == WSC_Start) {
457 		wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d",
458 			   op_code);
459 		ret->ignore = TRUE;
460 		return NULL;
461 	}
462 
463 	if (data->in_buf &&
464 	    eap_wsc_process_cont(data, pos, end - pos, op_code) < 0) {
465 		ret->ignore = TRUE;
466 		return NULL;
467 	}
468 
469 	if (flags & WSC_FLAGS_MF) {
470 		return eap_wsc_process_fragment(data, ret, id, flags, op_code,
471 						message_length, pos,
472 						end - pos);
473 	}
474 
475 	if (data->in_buf == NULL) {
476 		/* Wrap unfragmented messages as wpabuf without extra copy */
477 		wpabuf_set(&tmpbuf, pos, end - pos);
478 		data->in_buf = &tmpbuf;
479 	}
480 
481 	res = wps_process_msg(data->wps, op_code, data->in_buf);
482 	switch (res) {
483 	case WPS_DONE:
484 		wpa_printf(MSG_DEBUG, "EAP-WSC: WPS processing completed "
485 			   "successfully - wait for EAP failure");
486 		eap_wsc_state(data, FAIL);
487 		break;
488 	case WPS_CONTINUE:
489 		eap_wsc_state(data, MESG);
490 		break;
491 	case WPS_FAILURE:
492 	case WPS_PENDING:
493 		wpa_printf(MSG_DEBUG, "EAP-WSC: WPS processing failed");
494 		eap_wsc_state(data, FAIL);
495 		break;
496 	}
497 
498 	if (data->in_buf != &tmpbuf)
499 		wpabuf_free(data->in_buf);
500 	data->in_buf = NULL;
501 
502 send_msg:
503 	if (data->out_buf == NULL) {
504 		data->out_buf = wps_get_msg(data->wps, &data->out_op_code);
505 		if (data->out_buf == NULL) {
506 			wpa_printf(MSG_DEBUG, "EAP-WSC: Failed to receive "
507 				   "message from WPS");
508 			return NULL;
509 		}
510 		data->out_used = 0;
511 	}
512 
513 	eap_wsc_state(data, MESG);
514 	r = eap_wsc_build_msg(data, ret, id);
515 	if (data->state == FAIL && ret->methodState == METHOD_DONE) {
516 		/* Use reduced client timeout for WPS to avoid long wait */
517 		if (sm->ClientTimeout > 2)
518 			sm->ClientTimeout = 2;
519 	}
520 	return r;
521 }
522 
523 
524 int eap_peer_wsc_register(void)
525 {
526 	struct eap_method *eap;
527 	int ret;
528 
529 	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
530 				    EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC,
531 				    "WSC");
532 	if (eap == NULL)
533 		return -1;
534 
535 	eap->init = eap_wsc_init;
536 	eap->deinit = eap_wsc_deinit;
537 	eap->process = eap_wsc_process;
538 
539 	ret = eap_peer_method_register(eap);
540 	if (ret)
541 		eap_peer_method_free(eap);
542 	return ret;
543 }
544