Line data Source code
1 : /*
2 : * EAP server method: EAP-TNC (Trusted Network Connect)
3 : * Copyright (c) 2007-2010, 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 "eap_i.h"
13 : #include "tncs.h"
14 :
15 :
16 : struct eap_tnc_data {
17 : enum eap_tnc_state {
18 : START, CONTINUE, RECOMMENDATION, FRAG_ACK, WAIT_FRAG_ACK, DONE,
19 : FAIL
20 : } state;
21 : enum { ALLOW, ISOLATE, NO_ACCESS, NO_RECOMMENDATION } recommendation;
22 : struct tncs_data *tncs;
23 : struct wpabuf *in_buf;
24 : struct wpabuf *out_buf;
25 : size_t out_used;
26 : size_t fragment_size;
27 : unsigned int was_done:1;
28 : unsigned int was_fail:1;
29 : };
30 :
31 :
32 : /* EAP-TNC Flags */
33 : #define EAP_TNC_FLAGS_LENGTH_INCLUDED 0x80
34 : #define EAP_TNC_FLAGS_MORE_FRAGMENTS 0x40
35 : #define EAP_TNC_FLAGS_START 0x20
36 : #define EAP_TNC_VERSION_MASK 0x07
37 :
38 : #define EAP_TNC_VERSION 1
39 :
40 :
41 94 : static const char * eap_tnc_state_txt(enum eap_tnc_state state)
42 : {
43 94 : switch (state) {
44 : case START:
45 9 : return "START";
46 : case CONTINUE:
47 40 : return "CONTINUE";
48 : case RECOMMENDATION:
49 6 : return "RECOMMENDATION";
50 : case FRAG_ACK:
51 0 : return "FRAG_ACK";
52 : case WAIT_FRAG_ACK:
53 34 : return "WAIT_FRAG_ACK";
54 : case DONE:
55 5 : return "DONE";
56 : case FAIL:
57 0 : return "FAIL";
58 : }
59 0 : return "??";
60 : }
61 :
62 :
63 47 : static void eap_tnc_set_state(struct eap_tnc_data *data,
64 : enum eap_tnc_state new_state)
65 : {
66 47 : wpa_printf(MSG_DEBUG, "EAP-TNC: %s -> %s",
67 : eap_tnc_state_txt(data->state),
68 : eap_tnc_state_txt(new_state));
69 47 : data->state = new_state;
70 47 : }
71 :
72 :
73 3 : static void * eap_tnc_init(struct eap_sm *sm)
74 : {
75 : struct eap_tnc_data *data;
76 :
77 3 : data = os_zalloc(sizeof(*data));
78 3 : if (data == NULL)
79 0 : return NULL;
80 3 : eap_tnc_set_state(data, START);
81 3 : data->tncs = tncs_init();
82 3 : if (data->tncs == NULL) {
83 0 : os_free(data);
84 0 : return NULL;
85 : }
86 :
87 4 : data->fragment_size = sm->fragment_size > 100 ?
88 1 : sm->fragment_size - 98 : 1300;
89 :
90 3 : return data;
91 : }
92 :
93 :
94 3 : static void eap_tnc_reset(struct eap_sm *sm, void *priv)
95 : {
96 3 : struct eap_tnc_data *data = priv;
97 3 : wpabuf_free(data->in_buf);
98 3 : wpabuf_free(data->out_buf);
99 3 : tncs_deinit(data->tncs);
100 3 : os_free(data);
101 3 : }
102 :
103 :
104 3 : static struct wpabuf * eap_tnc_build_start(struct eap_sm *sm,
105 : struct eap_tnc_data *data, u8 id)
106 : {
107 : struct wpabuf *req;
108 :
109 3 : req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_TNC, 1, EAP_CODE_REQUEST,
110 : id);
111 3 : if (req == NULL) {
112 0 : wpa_printf(MSG_ERROR, "EAP-TNC: Failed to allocate memory for "
113 : "request");
114 0 : eap_tnc_set_state(data, FAIL);
115 0 : return NULL;
116 : }
117 :
118 3 : wpabuf_put_u8(req, EAP_TNC_FLAGS_START | EAP_TNC_VERSION);
119 :
120 3 : eap_tnc_set_state(data, CONTINUE);
121 :
122 3 : return req;
123 : }
124 :
125 :
126 6 : static struct wpabuf * eap_tnc_build(struct eap_sm *sm,
127 : struct eap_tnc_data *data)
128 : {
129 : struct wpabuf *req;
130 : u8 *rpos, *rpos1;
131 : size_t rlen;
132 : char *start_buf, *end_buf;
133 : size_t start_len, end_len;
134 : size_t imv_len;
135 :
136 6 : imv_len = tncs_total_send_len(data->tncs);
137 :
138 6 : start_buf = tncs_if_tnccs_start(data->tncs);
139 6 : if (start_buf == NULL)
140 0 : return NULL;
141 6 : start_len = os_strlen(start_buf);
142 6 : end_buf = tncs_if_tnccs_end();
143 6 : if (end_buf == NULL) {
144 0 : os_free(start_buf);
145 0 : return NULL;
146 : }
147 6 : end_len = os_strlen(end_buf);
148 :
149 6 : rlen = start_len + imv_len + end_len;
150 6 : req = wpabuf_alloc(rlen);
151 6 : if (req == NULL) {
152 0 : os_free(start_buf);
153 0 : os_free(end_buf);
154 0 : return NULL;
155 : }
156 :
157 6 : wpabuf_put_data(req, start_buf, start_len);
158 6 : os_free(start_buf);
159 :
160 6 : rpos1 = wpabuf_put(req, 0);
161 6 : rpos = tncs_copy_send_buf(data->tncs, rpos1);
162 6 : wpabuf_put(req, rpos - rpos1);
163 :
164 6 : wpabuf_put_data(req, end_buf, end_len);
165 6 : os_free(end_buf);
166 :
167 6 : wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-TNC: Request",
168 : wpabuf_head(req), wpabuf_len(req));
169 :
170 6 : return req;
171 : }
172 :
173 :
174 3 : static struct wpabuf * eap_tnc_build_recommendation(struct eap_sm *sm,
175 : struct eap_tnc_data *data)
176 : {
177 3 : switch (data->recommendation) {
178 : case ALLOW:
179 3 : eap_tnc_set_state(data, DONE);
180 3 : break;
181 : case ISOLATE:
182 0 : eap_tnc_set_state(data, FAIL);
183 : /* TODO: support assignment to a different VLAN */
184 0 : break;
185 : case NO_ACCESS:
186 0 : eap_tnc_set_state(data, FAIL);
187 0 : break;
188 : case NO_RECOMMENDATION:
189 0 : eap_tnc_set_state(data, DONE);
190 0 : break;
191 : default:
192 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: Unknown recommendation");
193 0 : return NULL;
194 : }
195 :
196 3 : return eap_tnc_build(sm, data);
197 : }
198 :
199 :
200 0 : static struct wpabuf * eap_tnc_build_frag_ack(u8 id, u8 code)
201 : {
202 : struct wpabuf *msg;
203 :
204 0 : msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_TNC, 1, code, id);
205 0 : if (msg == NULL) {
206 0 : wpa_printf(MSG_ERROR, "EAP-TNC: Failed to allocate memory "
207 : "for fragment ack");
208 0 : return NULL;
209 : }
210 0 : wpabuf_put_u8(msg, EAP_TNC_VERSION); /* Flags */
211 :
212 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: Send fragment ack");
213 :
214 0 : return msg;
215 : }
216 :
217 :
218 23 : static struct wpabuf * eap_tnc_build_msg(struct eap_tnc_data *data, u8 id)
219 : {
220 : struct wpabuf *req;
221 : u8 flags;
222 : size_t send_len, plen;
223 :
224 23 : wpa_printf(MSG_DEBUG, "EAP-TNC: Generating Request");
225 :
226 23 : flags = EAP_TNC_VERSION;
227 23 : send_len = wpabuf_len(data->out_buf) - data->out_used;
228 23 : if (1 + send_len > data->fragment_size) {
229 17 : send_len = data->fragment_size - 1;
230 17 : flags |= EAP_TNC_FLAGS_MORE_FRAGMENTS;
231 17 : if (data->out_used == 0) {
232 2 : flags |= EAP_TNC_FLAGS_LENGTH_INCLUDED;
233 2 : send_len -= 4;
234 : }
235 : }
236 :
237 23 : plen = 1 + send_len;
238 23 : if (flags & EAP_TNC_FLAGS_LENGTH_INCLUDED)
239 2 : plen += 4;
240 23 : req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_TNC, plen,
241 : EAP_CODE_REQUEST, id);
242 23 : if (req == NULL)
243 0 : return NULL;
244 :
245 23 : wpabuf_put_u8(req, flags); /* Flags */
246 23 : if (flags & EAP_TNC_FLAGS_LENGTH_INCLUDED)
247 2 : wpabuf_put_be32(req, wpabuf_len(data->out_buf));
248 :
249 23 : wpabuf_put_data(req, wpabuf_head_u8(data->out_buf) + data->out_used,
250 : send_len);
251 23 : data->out_used += send_len;
252 :
253 23 : if (data->out_used == wpabuf_len(data->out_buf)) {
254 6 : wpa_printf(MSG_DEBUG, "EAP-TNC: Sending out %lu bytes "
255 : "(message sent completely)",
256 : (unsigned long) send_len);
257 6 : wpabuf_free(data->out_buf);
258 6 : data->out_buf = NULL;
259 6 : data->out_used = 0;
260 6 : if (data->was_fail)
261 0 : eap_tnc_set_state(data, FAIL);
262 6 : else if (data->was_done)
263 1 : eap_tnc_set_state(data, DONE);
264 : } else {
265 17 : wpa_printf(MSG_DEBUG, "EAP-TNC: Sending out %lu bytes "
266 : "(%lu more to send)", (unsigned long) send_len,
267 17 : (unsigned long) wpabuf_len(data->out_buf) -
268 17 : data->out_used);
269 17 : if (data->state == FAIL)
270 0 : data->was_fail = 1;
271 17 : else if (data->state == DONE)
272 1 : data->was_done = 1;
273 17 : eap_tnc_set_state(data, WAIT_FRAG_ACK);
274 : }
275 :
276 23 : return req;
277 : }
278 :
279 :
280 26 : static struct wpabuf * eap_tnc_buildReq(struct eap_sm *sm, void *priv, u8 id)
281 : {
282 26 : struct eap_tnc_data *data = priv;
283 :
284 26 : switch (data->state) {
285 : case START:
286 3 : tncs_init_connection(data->tncs);
287 3 : return eap_tnc_build_start(sm, data, id);
288 : case CONTINUE:
289 20 : if (data->out_buf == NULL) {
290 3 : data->out_buf = eap_tnc_build(sm, data);
291 3 : if (data->out_buf == NULL) {
292 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: Failed to "
293 : "generate message");
294 0 : return NULL;
295 : }
296 3 : data->out_used = 0;
297 : }
298 20 : return eap_tnc_build_msg(data, id);
299 : case RECOMMENDATION:
300 3 : if (data->out_buf == NULL) {
301 3 : data->out_buf = eap_tnc_build_recommendation(sm, data);
302 3 : if (data->out_buf == NULL) {
303 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: Failed to "
304 : "generate recommendation message");
305 0 : return NULL;
306 : }
307 3 : data->out_used = 0;
308 : }
309 3 : return eap_tnc_build_msg(data, id);
310 : case WAIT_FRAG_ACK:
311 0 : return eap_tnc_build_msg(data, id);
312 : case FRAG_ACK:
313 0 : return eap_tnc_build_frag_ack(id, EAP_CODE_REQUEST);
314 : case DONE:
315 : case FAIL:
316 0 : return NULL;
317 : }
318 :
319 0 : return NULL;
320 : }
321 :
322 :
323 26 : static Boolean eap_tnc_check(struct eap_sm *sm, void *priv,
324 : struct wpabuf *respData)
325 : {
326 26 : struct eap_tnc_data *data = priv;
327 : const u8 *pos;
328 : size_t len;
329 :
330 26 : pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_TNC, respData,
331 : &len);
332 26 : if (pos == NULL) {
333 0 : wpa_printf(MSG_INFO, "EAP-TNC: Invalid frame");
334 0 : return TRUE;
335 : }
336 :
337 26 : if (len == 0 && data->state != WAIT_FRAG_ACK) {
338 0 : wpa_printf(MSG_INFO, "EAP-TNC: Invalid frame (empty)");
339 0 : return TRUE;
340 : }
341 :
342 26 : if (len == 0)
343 0 : return FALSE; /* Fragment ACK does not include flags */
344 :
345 26 : if ((*pos & EAP_TNC_VERSION_MASK) != EAP_TNC_VERSION) {
346 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: Unsupported version %d",
347 0 : *pos & EAP_TNC_VERSION_MASK);
348 0 : return TRUE;
349 : }
350 :
351 26 : if (*pos & EAP_TNC_FLAGS_START) {
352 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: Peer used Start flag");
353 0 : return TRUE;
354 : }
355 :
356 26 : return FALSE;
357 : }
358 :
359 :
360 6 : static void tncs_process(struct eap_tnc_data *data, struct wpabuf *inbuf)
361 : {
362 : enum tncs_process_res res;
363 :
364 6 : res = tncs_process_if_tnccs(data->tncs, wpabuf_head(inbuf),
365 : wpabuf_len(inbuf));
366 6 : switch (res) {
367 : case TNCCS_RECOMMENDATION_ALLOW:
368 3 : wpa_printf(MSG_DEBUG, "EAP-TNC: TNCS allowed access");
369 3 : eap_tnc_set_state(data, RECOMMENDATION);
370 3 : data->recommendation = ALLOW;
371 3 : break;
372 : case TNCCS_RECOMMENDATION_NO_RECOMMENDATION:
373 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: TNCS has no recommendation");
374 0 : eap_tnc_set_state(data, RECOMMENDATION);
375 0 : data->recommendation = NO_RECOMMENDATION;
376 0 : break;
377 : case TNCCS_RECOMMENDATION_ISOLATE:
378 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: TNCS requested isolation");
379 0 : eap_tnc_set_state(data, RECOMMENDATION);
380 0 : data->recommendation = ISOLATE;
381 0 : break;
382 : case TNCCS_RECOMMENDATION_NO_ACCESS:
383 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: TNCS rejected access");
384 0 : eap_tnc_set_state(data, RECOMMENDATION);
385 0 : data->recommendation = NO_ACCESS;
386 0 : break;
387 : case TNCCS_PROCESS_ERROR:
388 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: TNCS processing error");
389 0 : eap_tnc_set_state(data, FAIL);
390 0 : break;
391 : default:
392 3 : break;
393 : }
394 6 : }
395 :
396 :
397 0 : static int eap_tnc_process_cont(struct eap_tnc_data *data,
398 : const u8 *buf, size_t len)
399 : {
400 : /* Process continuation of a pending message */
401 0 : if (len > wpabuf_tailroom(data->in_buf)) {
402 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: Fragment overflow");
403 0 : eap_tnc_set_state(data, FAIL);
404 0 : return -1;
405 : }
406 :
407 0 : wpabuf_put_data(data->in_buf, buf, len);
408 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: Received %lu bytes, waiting for %lu "
409 : "bytes more", (unsigned long) len,
410 0 : (unsigned long) wpabuf_tailroom(data->in_buf));
411 :
412 0 : return 0;
413 : }
414 :
415 :
416 0 : static int eap_tnc_process_fragment(struct eap_tnc_data *data,
417 : u8 flags, u32 message_length,
418 : const u8 *buf, size_t len)
419 : {
420 : /* Process a fragment that is not the last one of the message */
421 0 : if (data->in_buf == NULL && !(flags & EAP_TNC_FLAGS_LENGTH_INCLUDED)) {
422 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: No Message Length field in a "
423 : "fragmented packet");
424 0 : return -1;
425 : }
426 :
427 0 : if (data->in_buf == NULL) {
428 : /* First fragment of the message */
429 0 : data->in_buf = wpabuf_alloc(message_length);
430 0 : if (data->in_buf == NULL) {
431 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: No memory for "
432 : "message");
433 0 : return -1;
434 : }
435 0 : wpabuf_put_data(data->in_buf, buf, len);
436 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: Received %lu bytes in first "
437 : "fragment, waiting for %lu bytes more",
438 : (unsigned long) len,
439 0 : (unsigned long) wpabuf_tailroom(data->in_buf));
440 : }
441 :
442 0 : return 0;
443 : }
444 :
445 :
446 26 : static void eap_tnc_process(struct eap_sm *sm, void *priv,
447 : struct wpabuf *respData)
448 : {
449 26 : struct eap_tnc_data *data = priv;
450 : const u8 *pos, *end;
451 : size_t len;
452 : u8 flags;
453 26 : u32 message_length = 0;
454 : struct wpabuf tmpbuf;
455 :
456 26 : pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_TNC, respData, &len);
457 26 : if (pos == NULL)
458 20 : return; /* Should not happen; message already verified */
459 :
460 26 : end = pos + len;
461 :
462 26 : if (len == 1 && (data->state == DONE || data->state == FAIL)) {
463 3 : wpa_printf(MSG_DEBUG, "EAP-TNC: Peer acknowledged the last "
464 : "message");
465 3 : return;
466 : }
467 :
468 23 : if (len == 0) {
469 : /* fragment ack */
470 0 : flags = 0;
471 : } else
472 23 : flags = *pos++;
473 :
474 23 : if (flags & EAP_TNC_FLAGS_LENGTH_INCLUDED) {
475 0 : if (end - pos < 4) {
476 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: Message underflow");
477 0 : eap_tnc_set_state(data, FAIL);
478 0 : return;
479 : }
480 0 : message_length = WPA_GET_BE32(pos);
481 0 : pos += 4;
482 :
483 0 : if (message_length < (u32) (end - pos) ||
484 : message_length > 75000) {
485 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: Invalid Message "
486 : "Length (%d; %ld remaining in this msg)",
487 : message_length, (long) (end - pos));
488 0 : eap_tnc_set_state(data, FAIL);
489 0 : return;
490 : }
491 : }
492 23 : wpa_printf(MSG_DEBUG, "EAP-TNC: Received packet: Flags 0x%x "
493 : "Message Length %u", flags, message_length);
494 :
495 23 : if (data->state == WAIT_FRAG_ACK) {
496 17 : if (len > 1) {
497 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: Unexpected payload "
498 : "in WAIT_FRAG_ACK state");
499 0 : eap_tnc_set_state(data, FAIL);
500 0 : return;
501 : }
502 17 : wpa_printf(MSG_DEBUG, "EAP-TNC: Fragment acknowledged");
503 17 : eap_tnc_set_state(data, CONTINUE);
504 17 : return;
505 : }
506 :
507 6 : if (data->in_buf && eap_tnc_process_cont(data, pos, end - pos) < 0) {
508 0 : eap_tnc_set_state(data, FAIL);
509 0 : return;
510 : }
511 :
512 6 : if (flags & EAP_TNC_FLAGS_MORE_FRAGMENTS) {
513 0 : if (eap_tnc_process_fragment(data, flags, message_length,
514 0 : pos, end - pos) < 0)
515 0 : eap_tnc_set_state(data, FAIL);
516 : else
517 0 : eap_tnc_set_state(data, FRAG_ACK);
518 0 : return;
519 6 : } else if (data->state == FRAG_ACK) {
520 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: All fragments received");
521 0 : eap_tnc_set_state(data, CONTINUE);
522 : }
523 :
524 6 : if (data->in_buf == NULL) {
525 : /* Wrap unfragmented messages as wpabuf without extra copy */
526 6 : wpabuf_set(&tmpbuf, pos, end - pos);
527 6 : data->in_buf = &tmpbuf;
528 : }
529 :
530 12 : wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-TNC: Received payload",
531 12 : wpabuf_head(data->in_buf), wpabuf_len(data->in_buf));
532 6 : tncs_process(data, data->in_buf);
533 :
534 6 : if (data->in_buf != &tmpbuf)
535 0 : wpabuf_free(data->in_buf);
536 6 : data->in_buf = NULL;
537 : }
538 :
539 :
540 26 : static Boolean eap_tnc_isDone(struct eap_sm *sm, void *priv)
541 : {
542 26 : struct eap_tnc_data *data = priv;
543 26 : return data->state == DONE || data->state == FAIL;
544 : }
545 :
546 :
547 3 : static Boolean eap_tnc_isSuccess(struct eap_sm *sm, void *priv)
548 : {
549 3 : struct eap_tnc_data *data = priv;
550 3 : return data->state == DONE;
551 : }
552 :
553 :
554 10 : int eap_server_tnc_register(void)
555 : {
556 : struct eap_method *eap;
557 : int ret;
558 :
559 10 : eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
560 : EAP_VENDOR_IETF, EAP_TYPE_TNC, "TNC");
561 10 : if (eap == NULL)
562 0 : return -1;
563 :
564 10 : eap->init = eap_tnc_init;
565 10 : eap->reset = eap_tnc_reset;
566 10 : eap->buildReq = eap_tnc_buildReq;
567 10 : eap->check = eap_tnc_check;
568 10 : eap->process = eap_tnc_process;
569 10 : eap->isDone = eap_tnc_isDone;
570 10 : eap->isSuccess = eap_tnc_isSuccess;
571 :
572 10 : ret = eap_server_method_register(eap);
573 10 : if (ret)
574 0 : eap_server_method_free(eap);
575 10 : return ret;
576 : }
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