Line data Source code
1 : /*
2 : * EAP peer method: EAP-TNC (Trusted Network Connect)
3 : * Copyright (c) 2007, 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 "tncc.h"
14 :
15 :
16 : struct eap_tnc_data {
17 : enum { WAIT_START, PROC_MSG, WAIT_FRAG_ACK, DONE, FAIL } state;
18 : struct tncc_data *tncc;
19 : struct wpabuf *in_buf;
20 : struct wpabuf *out_buf;
21 : size_t out_used;
22 : size_t fragment_size;
23 : };
24 :
25 :
26 : /* EAP-TNC Flags */
27 : #define EAP_TNC_FLAGS_LENGTH_INCLUDED 0x80
28 : #define EAP_TNC_FLAGS_MORE_FRAGMENTS 0x40
29 : #define EAP_TNC_FLAGS_START 0x20
30 : #define EAP_TNC_VERSION_MASK 0x07
31 :
32 : #define EAP_TNC_VERSION 1
33 :
34 :
35 2 : static void * eap_tnc_init(struct eap_sm *sm)
36 : {
37 : struct eap_tnc_data *data;
38 :
39 2 : data = os_zalloc(sizeof(*data));
40 2 : if (data == NULL)
41 0 : return NULL;
42 2 : data->state = WAIT_START;
43 2 : data->fragment_size = 1300;
44 2 : data->tncc = tncc_init();
45 2 : if (data->tncc == NULL) {
46 0 : os_free(data);
47 0 : return NULL;
48 : }
49 :
50 2 : return data;
51 : }
52 :
53 :
54 2 : static void eap_tnc_deinit(struct eap_sm *sm, void *priv)
55 : {
56 2 : struct eap_tnc_data *data = priv;
57 :
58 2 : wpabuf_free(data->in_buf);
59 2 : wpabuf_free(data->out_buf);
60 2 : tncc_deinit(data->tncc);
61 2 : os_free(data);
62 2 : }
63 :
64 :
65 0 : static struct wpabuf * eap_tnc_build_frag_ack(u8 id, u8 code)
66 : {
67 : struct wpabuf *msg;
68 :
69 0 : msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_TNC, 1, code, id);
70 0 : if (msg == NULL) {
71 0 : wpa_printf(MSG_ERROR, "EAP-TNC: Failed to allocate memory "
72 : "for fragment ack");
73 0 : return NULL;
74 : }
75 0 : wpabuf_put_u8(msg, EAP_TNC_VERSION); /* Flags */
76 :
77 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: Send fragment ack");
78 :
79 0 : return msg;
80 : }
81 :
82 :
83 4 : static struct wpabuf * eap_tnc_build_msg(struct eap_tnc_data *data,
84 : struct eap_method_ret *ret, u8 id)
85 : {
86 : struct wpabuf *resp;
87 : u8 flags;
88 : size_t send_len, plen;
89 :
90 4 : ret->ignore = FALSE;
91 4 : wpa_printf(MSG_DEBUG, "EAP-TNC: Generating Response");
92 4 : ret->allowNotifications = TRUE;
93 :
94 4 : flags = EAP_TNC_VERSION;
95 4 : send_len = wpabuf_len(data->out_buf) - data->out_used;
96 4 : if (1 + send_len > data->fragment_size) {
97 0 : send_len = data->fragment_size - 1;
98 0 : flags |= EAP_TNC_FLAGS_MORE_FRAGMENTS;
99 0 : if (data->out_used == 0) {
100 0 : flags |= EAP_TNC_FLAGS_LENGTH_INCLUDED;
101 0 : send_len -= 4;
102 : }
103 : }
104 :
105 4 : plen = 1 + send_len;
106 4 : if (flags & EAP_TNC_FLAGS_LENGTH_INCLUDED)
107 0 : plen += 4;
108 4 : resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_TNC, plen,
109 : EAP_CODE_RESPONSE, id);
110 4 : if (resp == NULL)
111 0 : return NULL;
112 :
113 4 : wpabuf_put_u8(resp, flags); /* Flags */
114 4 : if (flags & EAP_TNC_FLAGS_LENGTH_INCLUDED)
115 0 : wpabuf_put_be32(resp, wpabuf_len(data->out_buf));
116 :
117 4 : wpabuf_put_data(resp, wpabuf_head_u8(data->out_buf) + data->out_used,
118 : send_len);
119 4 : data->out_used += send_len;
120 :
121 4 : ret->methodState = METHOD_MAY_CONT;
122 4 : ret->decision = DECISION_FAIL;
123 :
124 4 : if (data->out_used == wpabuf_len(data->out_buf)) {
125 4 : wpa_printf(MSG_DEBUG, "EAP-TNC: Sending out %lu bytes "
126 : "(message sent completely)",
127 : (unsigned long) send_len);
128 4 : wpabuf_free(data->out_buf);
129 4 : data->out_buf = NULL;
130 4 : data->out_used = 0;
131 : } else {
132 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: Sending out %lu bytes "
133 : "(%lu more to send)", (unsigned long) send_len,
134 0 : (unsigned long) wpabuf_len(data->out_buf) -
135 0 : data->out_used);
136 0 : data->state = WAIT_FRAG_ACK;
137 : }
138 :
139 4 : return resp;
140 : }
141 :
142 :
143 0 : static int eap_tnc_process_cont(struct eap_tnc_data *data,
144 : const u8 *buf, size_t len)
145 : {
146 : /* Process continuation of a pending message */
147 0 : if (len > wpabuf_tailroom(data->in_buf)) {
148 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: Fragment overflow");
149 0 : data->state = FAIL;
150 0 : return -1;
151 : }
152 :
153 0 : wpabuf_put_data(data->in_buf, buf, len);
154 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: Received %lu bytes, waiting for "
155 : "%lu bytes more", (unsigned long) len,
156 0 : (unsigned long) wpabuf_tailroom(data->in_buf));
157 :
158 0 : return 0;
159 : }
160 :
161 :
162 0 : static struct wpabuf * eap_tnc_process_fragment(struct eap_tnc_data *data,
163 : struct eap_method_ret *ret,
164 : u8 id, u8 flags,
165 : u32 message_length,
166 : const u8 *buf, size_t len)
167 : {
168 : /* Process a fragment that is not the last one of the message */
169 0 : if (data->in_buf == NULL && !(flags & EAP_TNC_FLAGS_LENGTH_INCLUDED)) {
170 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: No Message Length field in a "
171 : "fragmented packet");
172 0 : ret->ignore = TRUE;
173 0 : return NULL;
174 : }
175 :
176 0 : if (data->in_buf == NULL) {
177 : /* First fragment of the message */
178 0 : data->in_buf = wpabuf_alloc(message_length);
179 0 : if (data->in_buf == NULL) {
180 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: No memory for "
181 : "message");
182 0 : ret->ignore = TRUE;
183 0 : return NULL;
184 : }
185 0 : wpabuf_put_data(data->in_buf, buf, len);
186 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: Received %lu bytes in first "
187 : "fragment, waiting for %lu bytes more",
188 : (unsigned long) len,
189 0 : (unsigned long) wpabuf_tailroom(data->in_buf));
190 : }
191 :
192 0 : return eap_tnc_build_frag_ack(id, EAP_CODE_RESPONSE);
193 : }
194 :
195 :
196 6 : static struct wpabuf * eap_tnc_process(struct eap_sm *sm, void *priv,
197 : struct eap_method_ret *ret,
198 : const struct wpabuf *reqData)
199 : {
200 6 : struct eap_tnc_data *data = priv;
201 : struct wpabuf *resp;
202 : const u8 *pos, *end;
203 : u8 *rpos, *rpos1;
204 : size_t len, rlen;
205 : size_t imc_len;
206 : char *start_buf, *end_buf;
207 : size_t start_len, end_len;
208 6 : int tncs_done = 0;
209 : u8 flags, id;
210 6 : u32 message_length = 0;
211 : struct wpabuf tmpbuf;
212 :
213 6 : pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_TNC, reqData, &len);
214 6 : if (pos == NULL) {
215 0 : wpa_printf(MSG_INFO, "EAP-TNC: Invalid frame (pos=%p len=%lu)",
216 : pos, (unsigned long) len);
217 0 : ret->ignore = TRUE;
218 0 : return NULL;
219 : }
220 :
221 6 : id = eap_get_id(reqData);
222 :
223 6 : end = pos + len;
224 :
225 6 : if (len == 0)
226 0 : flags = 0; /* fragment ack */
227 : else
228 6 : flags = *pos++;
229 :
230 6 : if (len > 0 && (flags & EAP_TNC_VERSION_MASK) != EAP_TNC_VERSION) {
231 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: Unsupported version %d",
232 : flags & EAP_TNC_VERSION_MASK);
233 0 : ret->ignore = TRUE;
234 0 : return NULL;
235 : }
236 :
237 6 : if (flags & EAP_TNC_FLAGS_LENGTH_INCLUDED) {
238 0 : if (end - pos < 4) {
239 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: Message underflow");
240 0 : ret->ignore = TRUE;
241 0 : return NULL;
242 : }
243 0 : message_length = WPA_GET_BE32(pos);
244 0 : pos += 4;
245 :
246 0 : if (message_length < (u32) (end - pos)) {
247 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: Invalid Message "
248 : "Length (%d; %ld remaining in this msg)",
249 : message_length, (long) (end - pos));
250 0 : ret->ignore = TRUE;
251 0 : return NULL;
252 : }
253 : }
254 :
255 6 : wpa_printf(MSG_DEBUG, "EAP-TNC: Received packet: Flags 0x%x "
256 : "Message Length %u", flags, message_length);
257 :
258 6 : if (data->state == WAIT_FRAG_ACK) {
259 0 : if (len > 1) {
260 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: Unexpected payload in "
261 : "WAIT_FRAG_ACK state");
262 0 : ret->ignore = TRUE;
263 0 : return NULL;
264 : }
265 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: Fragment acknowledged");
266 0 : data->state = PROC_MSG;
267 0 : return eap_tnc_build_msg(data, ret, id);
268 : }
269 :
270 6 : if (data->in_buf && eap_tnc_process_cont(data, pos, end - pos) < 0) {
271 0 : ret->ignore = TRUE;
272 0 : return NULL;
273 : }
274 :
275 6 : if (flags & EAP_TNC_FLAGS_MORE_FRAGMENTS) {
276 0 : return eap_tnc_process_fragment(data, ret, id, flags,
277 : message_length, pos,
278 0 : end - pos);
279 : }
280 :
281 6 : if (data->in_buf == NULL) {
282 : /* Wrap unfragmented messages as wpabuf without extra copy */
283 6 : wpabuf_set(&tmpbuf, pos, end - pos);
284 6 : data->in_buf = &tmpbuf;
285 : }
286 :
287 6 : if (data->state == WAIT_START) {
288 2 : if (!(flags & EAP_TNC_FLAGS_START)) {
289 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: Server did not use "
290 : "start flag in the first message");
291 0 : ret->ignore = TRUE;
292 0 : goto fail;
293 : }
294 :
295 2 : tncc_init_connection(data->tncc);
296 :
297 2 : data->state = PROC_MSG;
298 : } else {
299 : enum tncc_process_res res;
300 :
301 4 : if (flags & EAP_TNC_FLAGS_START) {
302 0 : wpa_printf(MSG_DEBUG, "EAP-TNC: Server used start "
303 : "flag again");
304 0 : ret->ignore = TRUE;
305 0 : goto fail;
306 : }
307 :
308 8 : res = tncc_process_if_tnccs(data->tncc,
309 4 : wpabuf_head(data->in_buf),
310 4 : wpabuf_len(data->in_buf));
311 4 : switch (res) {
312 : case TNCCS_PROCESS_ERROR:
313 0 : ret->ignore = TRUE;
314 0 : goto fail;
315 : case TNCCS_PROCESS_OK_NO_RECOMMENDATION:
316 : case TNCCS_RECOMMENDATION_ERROR:
317 2 : wpa_printf(MSG_DEBUG, "EAP-TNC: No "
318 : "TNCCS-Recommendation received");
319 2 : break;
320 : case TNCCS_RECOMMENDATION_ALLOW:
321 2 : wpa_msg(sm->msg_ctx, MSG_INFO,
322 : "TNC: Recommendation = allow");
323 2 : tncs_done = 1;
324 2 : break;
325 : case TNCCS_RECOMMENDATION_NONE:
326 0 : wpa_msg(sm->msg_ctx, MSG_INFO,
327 : "TNC: Recommendation = none");
328 0 : tncs_done = 1;
329 0 : break;
330 : case TNCCS_RECOMMENDATION_ISOLATE:
331 0 : wpa_msg(sm->msg_ctx, MSG_INFO,
332 : "TNC: Recommendation = isolate");
333 0 : tncs_done = 1;
334 0 : break;
335 : }
336 : }
337 :
338 6 : if (data->in_buf != &tmpbuf)
339 0 : wpabuf_free(data->in_buf);
340 6 : data->in_buf = NULL;
341 :
342 6 : ret->ignore = FALSE;
343 6 : ret->methodState = METHOD_MAY_CONT;
344 6 : ret->decision = DECISION_UNCOND_SUCC;
345 6 : ret->allowNotifications = TRUE;
346 :
347 6 : if (data->out_buf) {
348 0 : data->state = PROC_MSG;
349 0 : return eap_tnc_build_msg(data, ret, id);
350 : }
351 :
352 6 : if (tncs_done) {
353 2 : resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_TNC, 1,
354 2 : EAP_CODE_RESPONSE, eap_get_id(reqData));
355 2 : if (resp == NULL)
356 0 : return NULL;
357 :
358 2 : wpabuf_put_u8(resp, EAP_TNC_VERSION);
359 2 : wpa_printf(MSG_DEBUG, "EAP-TNC: TNCS done - reply with an "
360 : "empty ACK message");
361 2 : return resp;
362 : }
363 :
364 4 : imc_len = tncc_total_send_len(data->tncc);
365 :
366 4 : start_buf = tncc_if_tnccs_start(data->tncc);
367 4 : if (start_buf == NULL)
368 0 : return NULL;
369 4 : start_len = os_strlen(start_buf);
370 4 : end_buf = tncc_if_tnccs_end();
371 4 : if (end_buf == NULL) {
372 0 : os_free(start_buf);
373 0 : return NULL;
374 : }
375 4 : end_len = os_strlen(end_buf);
376 :
377 4 : rlen = start_len + imc_len + end_len;
378 4 : resp = wpabuf_alloc(rlen);
379 4 : if (resp == NULL) {
380 0 : os_free(start_buf);
381 0 : os_free(end_buf);
382 0 : return NULL;
383 : }
384 :
385 4 : wpabuf_put_data(resp, start_buf, start_len);
386 4 : os_free(start_buf);
387 :
388 4 : rpos1 = wpabuf_put(resp, 0);
389 4 : rpos = tncc_copy_send_buf(data->tncc, rpos1);
390 4 : wpabuf_put(resp, rpos - rpos1);
391 :
392 4 : wpabuf_put_data(resp, end_buf, end_len);
393 4 : os_free(end_buf);
394 :
395 4 : wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-TNC: Response",
396 : wpabuf_head(resp), wpabuf_len(resp));
397 :
398 4 : data->out_buf = resp;
399 4 : data->state = PROC_MSG;
400 4 : return eap_tnc_build_msg(data, ret, id);
401 :
402 : fail:
403 0 : if (data->in_buf == &tmpbuf)
404 0 : data->in_buf = NULL;
405 0 : return NULL;
406 : }
407 :
408 :
409 4 : int eap_peer_tnc_register(void)
410 : {
411 : struct eap_method *eap;
412 : int ret;
413 :
414 4 : eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
415 : EAP_VENDOR_IETF, EAP_TYPE_TNC, "TNC");
416 4 : if (eap == NULL)
417 0 : return -1;
418 :
419 4 : eap->init = eap_tnc_init;
420 4 : eap->deinit = eap_tnc_deinit;
421 4 : eap->process = eap_tnc_process;
422 :
423 4 : ret = eap_peer_method_register(eap);
424 4 : if (ret)
425 0 : eap_peer_method_free(eap);
426 4 : return ret;
427 : }
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