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