1 /*
2 * EAP-WSC server for Wi-Fi Protected Setup
3 * Copyright (c) 2007-2008, 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 "eloop.h"
13 #include "eap_i.h"
14 #include "eap_common/eap_wsc_common.h"
15 #include "p2p/p2p.h"
16 #include "wps/wps.h"
17
18
19 struct eap_wsc_data {
20 enum { 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 int ext_reg_timeout;
29 };
30
31
32 #ifndef CONFIG_NO_STDOUT_DEBUG
eap_wsc_state_txt(int state)33 static const char * eap_wsc_state_txt(int state)
34 {
35 switch (state) {
36 case START:
37 return "START";
38 case MESG:
39 return "MESG";
40 case FRAG_ACK:
41 return "FRAG_ACK";
42 case WAIT_FRAG_ACK:
43 return "WAIT_FRAG_ACK";
44 case DONE:
45 return "DONE";
46 case FAIL:
47 return "FAIL";
48 default:
49 return "?";
50 }
51 }
52 #endif /* CONFIG_NO_STDOUT_DEBUG */
53
54
eap_wsc_state(struct eap_wsc_data * data,int state)55 static void eap_wsc_state(struct eap_wsc_data *data, int state)
56 {
57 #ifndef CONFIG_PRINT_NOUSE
58 wpa_printf(MSG_DEBUG, "EAP-WSC: %s -> %s",
59 eap_wsc_state_txt(data->state),
60 eap_wsc_state_txt(state));
61 #endif /* CONFIG_PRINT_NOUSE */
62 data->state = state;
63 }
64
65
eap_wsc_ext_reg_timeout(void * eloop_ctx,void * timeout_ctx)66 static void eap_wsc_ext_reg_timeout(void *eloop_ctx, void *timeout_ctx)
67 {
68 struct eap_sm *sm = eloop_ctx;
69 struct eap_wsc_data *data = timeout_ctx;
70
71 if (sm->method_pending != METHOD_PENDING_WAIT)
72 return;
73
74 wpa_printf(MSG_DEBUG, "EAP-WSC: Timeout while waiting for an External "
75 "Registrar");
76 data->ext_reg_timeout = 1;
77 eap_sm_pending_cb(sm);
78 }
79
80
eap_wsc_init(struct eap_sm * sm)81 static void * eap_wsc_init(struct eap_sm *sm)
82 {
83 struct eap_wsc_data *data;
84 int registrar;
85 struct wps_config cfg;
86
87 if (sm->identity && sm->identity_len == WSC_ID_REGISTRAR_LEN &&
88 os_memcmp(sm->identity, WSC_ID_REGISTRAR, WSC_ID_REGISTRAR_LEN) ==
89 0)
90 registrar = 0; /* Supplicant is Registrar */
91 else if (sm->identity && sm->identity_len == WSC_ID_ENROLLEE_LEN &&
92 os_memcmp(sm->identity, WSC_ID_ENROLLEE, WSC_ID_ENROLLEE_LEN)
93 == 0)
94 registrar = 1; /* Supplicant is Enrollee */
95 else {
96 wpa_hexdump_ascii(MSG_INFO, "EAP-WSC: Unexpected identity",
97 sm->identity, sm->identity_len);
98 return NULL;
99 }
100
101 data = os_zalloc(sizeof(*data));
102 if (data == NULL)
103 return NULL;
104 data->state = registrar ? START : MESG;
105 data->registrar = registrar;
106
107 os_memset(&cfg, 0, sizeof(cfg));
108 cfg.wps = sm->cfg->wps;
109 cfg.registrar = registrar;
110 if (registrar) {
111 if (!sm->cfg->wps || !sm->cfg->wps->registrar) {
112 wpa_printf(MSG_INFO, "EAP-WSC: WPS Registrar not "
113 "initialized");
114 os_free(data);
115 return NULL;
116 }
117 } else {
118 if (sm->user == NULL || sm->user->password == NULL) {
119 /*
120 * In theory, this should not really be needed, but
121 * Windows 7 uses Registrar mode to probe AP's WPS
122 * capabilities before trying to use Enrollee and fails
123 * if the AP does not allow that probing to happen..
124 */
125 wpa_printf(MSG_DEBUG, "EAP-WSC: No AP PIN (password) "
126 "configured for Enrollee functionality - "
127 "allow for probing capabilities (M1)");
128 } else {
129 cfg.pin = sm->user->password;
130 cfg.pin_len = sm->user->password_len;
131 }
132 }
133 cfg.assoc_wps_ie = sm->assoc_wps_ie;
134 cfg.peer_addr = sm->peer_addr;
135 #ifdef CONFIG_P2P
136 if (sm->assoc_p2p_ie) {
137 if (!sm->cfg->wps->use_passphrase) {
138 wpa_printf(MSG_DEBUG,
139 "EAP-WSC: Prefer PSK format for non-6 GHz P2P client");
140 cfg.use_psk_key = 1;
141 }
142 cfg.p2p_dev_addr = p2p_get_go_dev_addr(sm->assoc_p2p_ie);
143 }
144 #endif /* CONFIG_P2P */
145 cfg.pbc_in_m1 = sm->cfg->pbc_in_m1;
146 data->wps = wps_init(&cfg);
147 if (data->wps == NULL) {
148 os_free(data);
149 return NULL;
150 }
151 data->fragment_size = sm->cfg->fragment_size > 0 ?
152 sm->cfg->fragment_size : WSC_FRAGMENT_SIZE;
153
154 return data;
155 }
156
157
eap_wsc_reset(struct eap_sm * sm,void * priv)158 static void eap_wsc_reset(struct eap_sm *sm, void *priv)
159 {
160 struct eap_wsc_data *data = priv;
161 eloop_cancel_timeout(eap_wsc_ext_reg_timeout, sm, data);
162 wpabuf_free(data->in_buf);
163 wpabuf_free(data->out_buf);
164 wps_deinit(data->wps);
165 os_free(data);
166 }
167
168
eap_wsc_build_start(struct eap_sm * sm,struct eap_wsc_data * data,u8 id)169 static struct wpabuf * eap_wsc_build_start(struct eap_sm *sm,
170 struct eap_wsc_data *data, u8 id)
171 {
172 struct wpabuf *req;
173
174 req = eap_msg_alloc(EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC, 2,
175 EAP_CODE_REQUEST, id);
176 if (req == NULL) {
177 wpa_printf(MSG_ERROR, "EAP-WSC: Failed to allocate memory for "
178 "request");
179 return NULL;
180 }
181
182 wpa_printf(MSG_DEBUG, "EAP-WSC: Send WSC/Start");
183 wpabuf_put_u8(req, WSC_Start); /* Op-Code */
184 wpabuf_put_u8(req, 0); /* Flags */
185
186 return req;
187 }
188
189
eap_wsc_build_msg(struct eap_wsc_data * data,u8 id)190 static struct wpabuf * eap_wsc_build_msg(struct eap_wsc_data *data, u8 id)
191 {
192 struct wpabuf *req;
193 u8 flags;
194 size_t send_len, plen;
195
196 flags = 0;
197 send_len = wpabuf_len(data->out_buf) - data->out_used;
198 if (2 + send_len > data->fragment_size) {
199 send_len = data->fragment_size - 2;
200 flags |= WSC_FLAGS_MF;
201 if (data->out_used == 0) {
202 flags |= WSC_FLAGS_LF;
203 send_len -= 2;
204 }
205 }
206 plen = 2 + send_len;
207 if (flags & WSC_FLAGS_LF)
208 plen += 2;
209 req = eap_msg_alloc(EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC, plen,
210 EAP_CODE_REQUEST, id);
211 if (req == NULL) {
212 wpa_printf(MSG_ERROR, "EAP-WSC: Failed to allocate memory for "
213 "request");
214 return NULL;
215 }
216
217 wpabuf_put_u8(req, data->out_op_code); /* Op-Code */
218 wpabuf_put_u8(req, flags); /* Flags */
219 if (flags & WSC_FLAGS_LF)
220 wpabuf_put_be16(req, wpabuf_len(data->out_buf));
221
222 wpabuf_put_data(req, wpabuf_head_u8(data->out_buf) + data->out_used,
223 send_len);
224 data->out_used += send_len;
225
226 if (data->out_used == wpabuf_len(data->out_buf)) {
227 wpa_printf(MSG_DEBUG, "EAP-WSC: Sending out %lu bytes "
228 "(message sent completely)",
229 (unsigned long) send_len);
230 wpabuf_free(data->out_buf);
231 data->out_buf = NULL;
232 data->out_used = 0;
233 eap_wsc_state(data, MESG);
234 } else {
235 wpa_printf(MSG_DEBUG, "EAP-WSC: Sending out %lu bytes "
236 "(%lu more to send)", (unsigned long) send_len,
237 (unsigned long) wpabuf_len(data->out_buf) -
238 data->out_used);
239 eap_wsc_state(data, WAIT_FRAG_ACK);
240 }
241
242 return req;
243 }
244
245
eap_wsc_buildReq(struct eap_sm * sm,void * priv,u8 id)246 static struct wpabuf * eap_wsc_buildReq(struct eap_sm *sm, void *priv, u8 id)
247 {
248 struct eap_wsc_data *data = priv;
249
250 switch (data->state) {
251 case START:
252 return eap_wsc_build_start(sm, data, id);
253 case MESG:
254 if (data->out_buf == NULL) {
255 data->out_buf = wps_get_msg(data->wps,
256 &data->out_op_code);
257 if (data->out_buf == NULL) {
258 wpa_printf(MSG_DEBUG, "EAP-WSC: Failed to "
259 "receive message from WPS");
260 return NULL;
261 }
262 data->out_used = 0;
263 }
264 /* fall through */
265 case WAIT_FRAG_ACK:
266 return eap_wsc_build_msg(data, id);
267 case FRAG_ACK:
268 return eap_wsc_build_frag_ack(id, EAP_CODE_REQUEST);
269 default:
270 wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected state %d in "
271 "buildReq", data->state);
272 return NULL;
273 }
274 }
275
276
eap_wsc_check(struct eap_sm * sm,void * priv,struct wpabuf * respData)277 static bool eap_wsc_check(struct eap_sm *sm, void *priv,
278 struct wpabuf *respData)
279 {
280 const u8 *pos;
281 size_t len;
282
283 pos = eap_hdr_validate(EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC,
284 respData, &len);
285 if (pos == NULL || len < 2) {
286 wpa_printf(MSG_INFO, "EAP-WSC: Invalid frame");
287 return true;
288 }
289
290 return false;
291 }
292
293
eap_wsc_process_cont(struct eap_wsc_data * data,const u8 * buf,size_t len,u8 op_code)294 static int eap_wsc_process_cont(struct eap_wsc_data *data,
295 const u8 *buf, size_t len, u8 op_code)
296 {
297 /* Process continuation of a pending message */
298 if (op_code != data->in_op_code) {
299 wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d in "
300 "fragment (expected %d)",
301 op_code, data->in_op_code);
302 eap_wsc_state(data, FAIL);
303 return -1;
304 }
305
306 if (len > wpabuf_tailroom(data->in_buf)) {
307 wpa_printf(MSG_DEBUG, "EAP-WSC: Fragment overflow");
308 eap_wsc_state(data, FAIL);
309 return -1;
310 }
311
312 wpabuf_put_data(data->in_buf, buf, len);
313 wpa_printf(MSG_DEBUG, "EAP-WSC: Received %lu bytes, waiting for %lu "
314 "bytes more", (unsigned long) len,
315 (unsigned long) wpabuf_tailroom(data->in_buf));
316
317 return 0;
318 }
319
320
eap_wsc_process_fragment(struct eap_wsc_data * data,u8 flags,u8 op_code,u16 message_length,const u8 * buf,size_t len)321 static int eap_wsc_process_fragment(struct eap_wsc_data *data,
322 u8 flags, u8 op_code, u16 message_length,
323 const u8 *buf, size_t len)
324 {
325 /* Process a fragment that is not the last one of the message */
326 if (data->in_buf == NULL && !(flags & WSC_FLAGS_LF)) {
327 wpa_printf(MSG_DEBUG, "EAP-WSC: No Message Length "
328 "field in a fragmented packet");
329 return -1;
330 }
331
332 if (data->in_buf == NULL) {
333 /* First fragment of the message */
334 data->in_buf = wpabuf_alloc(message_length);
335 if (data->in_buf == NULL) {
336 wpa_printf(MSG_DEBUG, "EAP-WSC: No memory for "
337 "message");
338 return -1;
339 }
340 data->in_op_code = op_code;
341 wpabuf_put_data(data->in_buf, buf, len);
342 wpa_printf(MSG_DEBUG, "EAP-WSC: Received %lu bytes in "
343 "first fragment, waiting for %lu bytes more",
344 (unsigned long) len,
345 (unsigned long) wpabuf_tailroom(data->in_buf));
346 }
347
348 return 0;
349 }
350
351
eap_wsc_process(struct eap_sm * sm,void * priv,struct wpabuf * respData)352 static void eap_wsc_process(struct eap_sm *sm, void *priv,
353 struct wpabuf *respData)
354 {
355 struct eap_wsc_data *data = priv;
356 const u8 *start, *pos, *end;
357 size_t len;
358 u8 op_code, flags;
359 u16 message_length = 0;
360 enum wps_process_res res;
361 struct wpabuf tmpbuf;
362
363 eloop_cancel_timeout(eap_wsc_ext_reg_timeout, sm, data);
364 if (data->ext_reg_timeout) {
365 eap_wsc_state(data, FAIL);
366 return;
367 }
368
369 pos = eap_hdr_validate(EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC,
370 respData, &len);
371 if (pos == NULL || len < 2)
372 return; /* Should not happen; message already verified */
373
374 start = pos;
375 end = start + len;
376
377 op_code = *pos++;
378 flags = *pos++;
379 if (flags & WSC_FLAGS_LF) {
380 if (end - pos < 2) {
381 wpa_printf(MSG_DEBUG, "EAP-WSC: Message underflow");
382 return;
383 }
384 message_length = WPA_GET_BE16(pos);
385 pos += 2;
386
387 if (message_length < end - pos || message_length > 50000) {
388 wpa_printf(MSG_DEBUG, "EAP-WSC: Invalid Message "
389 "Length");
390 return;
391 }
392 }
393
394 wpa_printf(MSG_DEBUG, "EAP-WSC: Received packet: Op-Code %d "
395 "Flags 0x%x Message Length %d",
396 op_code, flags, message_length);
397
398 if (data->state == WAIT_FRAG_ACK) {
399 if (op_code != WSC_FRAG_ACK) {
400 wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d "
401 "in WAIT_FRAG_ACK state", op_code);
402 eap_wsc_state(data, FAIL);
403 return;
404 }
405 wpa_printf(MSG_DEBUG, "EAP-WSC: Fragment acknowledged");
406 eap_wsc_state(data, MESG);
407 return;
408 }
409
410 if (op_code != WSC_ACK && op_code != WSC_NACK && op_code != WSC_MSG &&
411 op_code != WSC_Done) {
412 wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d",
413 op_code);
414 eap_wsc_state(data, FAIL);
415 return;
416 }
417
418 if (data->in_buf &&
419 eap_wsc_process_cont(data, pos, end - pos, op_code) < 0) {
420 eap_wsc_state(data, FAIL);
421 return;
422 }
423
424 if (flags & WSC_FLAGS_MF) {
425 if (eap_wsc_process_fragment(data, flags, op_code,
426 message_length, pos, end - pos) <
427 0)
428 eap_wsc_state(data, FAIL);
429 else
430 eap_wsc_state(data, FRAG_ACK);
431 return;
432 }
433
434 if (data->in_buf == NULL) {
435 /* Wrap unfragmented messages as wpabuf without extra copy */
436 wpabuf_set(&tmpbuf, pos, end - pos);
437 data->in_buf = &tmpbuf;
438 }
439
440 res = wps_process_msg(data->wps, op_code, data->in_buf);
441 switch (res) {
442 case WPS_DONE:
443 wpa_printf(MSG_DEBUG, "EAP-WSC: WPS processing completed "
444 "successfully - report EAP failure");
445 eap_wsc_state(data, FAIL);
446 break;
447 case WPS_CONTINUE:
448 eap_wsc_state(data, MESG);
449 break;
450 case WPS_FAILURE:
451 wpa_printf(MSG_DEBUG, "EAP-WSC: WPS processing failed");
452 eap_wsc_state(data, FAIL);
453 break;
454 case WPS_PENDING:
455 eap_wsc_state(data, MESG);
456 sm->method_pending = METHOD_PENDING_WAIT;
457 eloop_cancel_timeout(eap_wsc_ext_reg_timeout, sm, data);
458 eloop_register_timeout(5, 0, eap_wsc_ext_reg_timeout,
459 sm, data);
460 break;
461 }
462
463 if (data->in_buf != &tmpbuf)
464 wpabuf_free(data->in_buf);
465 data->in_buf = NULL;
466 }
467
468
eap_wsc_isDone(struct eap_sm * sm,void * priv)469 static bool eap_wsc_isDone(struct eap_sm *sm, void *priv)
470 {
471 struct eap_wsc_data *data = priv;
472 return data->state == FAIL;
473 }
474
475
eap_wsc_isSuccess(struct eap_sm * sm,void * priv)476 static bool eap_wsc_isSuccess(struct eap_sm *sm, void *priv)
477 {
478 /* EAP-WSC will always result in EAP-Failure */
479 return false;
480 }
481
482
eap_wsc_getTimeout(struct eap_sm * sm,void * priv)483 static int eap_wsc_getTimeout(struct eap_sm *sm, void *priv)
484 {
485 /* Recommended retransmit times: retransmit timeout 5 seconds,
486 * per-message timeout 15 seconds, i.e., 3 tries. */
487 sm->MaxRetrans = 2; /* total 3 attempts */
488 return 5;
489 }
490
491
eap_server_wsc_register(void)492 int eap_server_wsc_register(void)
493 {
494 struct eap_method *eap;
495
496 eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
497 EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC,
498 "WSC");
499 if (eap == NULL)
500 return -1;
501
502 eap->init = eap_wsc_init;
503 eap->reset = eap_wsc_reset;
504 eap->buildReq = eap_wsc_buildReq;
505 eap->check = eap_wsc_check;
506 eap->process = eap_wsc_process;
507 eap->isDone = eap_wsc_isDone;
508 eap->isSuccess = eap_wsc_isSuccess;
509 eap->getTimeout = eap_wsc_getTimeout;
510
511 return eap_server_method_register(eap);
512 }
513