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