Line data Source code
1 : /*
2 : * EAP peer method: EAP-SAKE (RFC 4763)
3 : * Copyright (c) 2006-2008, 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 "crypto/random.h"
13 : #include "eap_peer/eap_i.h"
14 : #include "eap_common/eap_sake_common.h"
15 :
16 : struct eap_sake_data {
17 : enum { IDENTITY, CHALLENGE, CONFIRM, SUCCESS, FAILURE } state;
18 : u8 root_secret_a[EAP_SAKE_ROOT_SECRET_LEN];
19 : u8 root_secret_b[EAP_SAKE_ROOT_SECRET_LEN];
20 : u8 rand_s[EAP_SAKE_RAND_LEN];
21 : u8 rand_p[EAP_SAKE_RAND_LEN];
22 : struct {
23 : u8 auth[EAP_SAKE_TEK_AUTH_LEN];
24 : u8 cipher[EAP_SAKE_TEK_CIPHER_LEN];
25 : } tek;
26 : u8 msk[EAP_MSK_LEN];
27 : u8 emsk[EAP_EMSK_LEN];
28 : u8 session_id;
29 : int session_id_set;
30 : u8 *peerid;
31 : size_t peerid_len;
32 : u8 *serverid;
33 : size_t serverid_len;
34 : };
35 :
36 :
37 16 : static const char * eap_sake_state_txt(int state)
38 : {
39 16 : switch (state) {
40 : case IDENTITY:
41 3 : return "IDENTITY";
42 : case CHALLENGE:
43 6 : return "CHALLENGE";
44 : case CONFIRM:
45 5 : return "CONFIRM";
46 : case SUCCESS:
47 2 : return "SUCCESS";
48 : case FAILURE:
49 0 : return "FAILURE";
50 : default:
51 0 : return "?";
52 : }
53 : }
54 :
55 :
56 8 : static void eap_sake_state(struct eap_sake_data *data, int state)
57 : {
58 16 : wpa_printf(MSG_DEBUG, "EAP-SAKE: %s -> %s",
59 8 : eap_sake_state_txt(data->state),
60 : eap_sake_state_txt(state));
61 8 : data->state = state;
62 8 : }
63 :
64 :
65 : static void eap_sake_deinit(struct eap_sm *sm, void *priv);
66 :
67 :
68 3 : static void * eap_sake_init(struct eap_sm *sm)
69 : {
70 : struct eap_sake_data *data;
71 : const u8 *identity, *password;
72 : size_t identity_len, password_len;
73 :
74 3 : password = eap_get_config_password(sm, &password_len);
75 3 : if (!password || password_len != 2 * EAP_SAKE_ROOT_SECRET_LEN) {
76 0 : wpa_printf(MSG_INFO, "EAP-SAKE: No key of correct length "
77 : "configured");
78 0 : return NULL;
79 : }
80 :
81 3 : data = os_zalloc(sizeof(*data));
82 3 : if (data == NULL)
83 0 : return NULL;
84 3 : data->state = IDENTITY;
85 :
86 3 : identity = eap_get_config_identity(sm, &identity_len);
87 3 : if (identity) {
88 3 : data->peerid = os_malloc(identity_len);
89 3 : if (data->peerid == NULL) {
90 0 : eap_sake_deinit(sm, data);
91 0 : return NULL;
92 : }
93 3 : os_memcpy(data->peerid, identity, identity_len);
94 3 : data->peerid_len = identity_len;
95 : }
96 :
97 3 : os_memcpy(data->root_secret_a, password, EAP_SAKE_ROOT_SECRET_LEN);
98 3 : os_memcpy(data->root_secret_b,
99 : password + EAP_SAKE_ROOT_SECRET_LEN,
100 : EAP_SAKE_ROOT_SECRET_LEN);
101 :
102 3 : return data;
103 : }
104 :
105 :
106 3 : static void eap_sake_deinit(struct eap_sm *sm, void *priv)
107 : {
108 3 : struct eap_sake_data *data = priv;
109 3 : os_free(data->serverid);
110 3 : os_free(data->peerid);
111 3 : os_free(data);
112 3 : }
113 :
114 :
115 5 : static struct wpabuf * eap_sake_build_msg(struct eap_sake_data *data,
116 : int id, size_t length, u8 subtype)
117 : {
118 : struct eap_sake_hdr *sake;
119 : struct wpabuf *msg;
120 : size_t plen;
121 :
122 5 : plen = length + sizeof(struct eap_sake_hdr);
123 :
124 5 : msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_SAKE, plen,
125 : EAP_CODE_RESPONSE, id);
126 5 : if (msg == NULL) {
127 0 : wpa_printf(MSG_ERROR, "EAP-SAKE: Failed to allocate memory "
128 : "request");
129 0 : return NULL;
130 : }
131 :
132 5 : sake = wpabuf_put(msg, sizeof(*sake));
133 5 : sake->version = EAP_SAKE_VERSION;
134 5 : sake->session_id = data->session_id;
135 5 : sake->subtype = subtype;
136 :
137 5 : return msg;
138 : }
139 :
140 :
141 0 : static struct wpabuf * eap_sake_process_identity(struct eap_sm *sm,
142 : struct eap_sake_data *data,
143 : struct eap_method_ret *ret,
144 : const struct wpabuf *reqData,
145 : const u8 *payload,
146 : size_t payload_len)
147 : {
148 : struct eap_sake_parse_attr attr;
149 : struct wpabuf *resp;
150 :
151 0 : if (data->state != IDENTITY) {
152 0 : ret->ignore = TRUE;
153 0 : return NULL;
154 : }
155 :
156 0 : wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Request/Identity");
157 :
158 0 : if (eap_sake_parse_attributes(payload, payload_len, &attr))
159 0 : return NULL;
160 :
161 0 : if (!attr.perm_id_req && !attr.any_id_req) {
162 0 : wpa_printf(MSG_INFO, "EAP-SAKE: No AT_PERM_ID_REQ or "
163 : "AT_ANY_ID_REQ in Request/Identity");
164 0 : return NULL;
165 : }
166 :
167 0 : wpa_printf(MSG_DEBUG, "EAP-SAKE: Sending Response/Identity");
168 :
169 0 : resp = eap_sake_build_msg(data, eap_get_id(reqData),
170 0 : 2 + data->peerid_len,
171 : EAP_SAKE_SUBTYPE_IDENTITY);
172 0 : if (resp == NULL)
173 0 : return NULL;
174 :
175 0 : wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_PEERID");
176 0 : eap_sake_add_attr(resp, EAP_SAKE_AT_PEERID,
177 0 : data->peerid, data->peerid_len);
178 :
179 0 : eap_sake_state(data, CHALLENGE);
180 :
181 0 : return resp;
182 : }
183 :
184 :
185 3 : static struct wpabuf * eap_sake_process_challenge(struct eap_sm *sm,
186 : struct eap_sake_data *data,
187 : struct eap_method_ret *ret,
188 : const struct wpabuf *reqData,
189 : const u8 *payload,
190 : size_t payload_len)
191 : {
192 : struct eap_sake_parse_attr attr;
193 : struct wpabuf *resp;
194 : u8 *rpos;
195 : size_t rlen;
196 :
197 3 : if (data->state != IDENTITY && data->state != CHALLENGE) {
198 0 : wpa_printf(MSG_DEBUG, "EAP-SAKE: Request/Challenge received "
199 0 : "in unexpected state (%d)", data->state);
200 0 : ret->ignore = TRUE;
201 0 : return NULL;
202 : }
203 3 : if (data->state == IDENTITY)
204 3 : eap_sake_state(data, CHALLENGE);
205 :
206 3 : wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Request/Challenge");
207 :
208 3 : if (eap_sake_parse_attributes(payload, payload_len, &attr))
209 0 : return NULL;
210 :
211 3 : if (!attr.rand_s) {
212 0 : wpa_printf(MSG_INFO, "EAP-SAKE: Request/Challenge did not "
213 : "include AT_RAND_S");
214 0 : return NULL;
215 : }
216 :
217 3 : os_memcpy(data->rand_s, attr.rand_s, EAP_SAKE_RAND_LEN);
218 3 : wpa_hexdump(MSG_MSGDUMP, "EAP-SAKE: RAND_S (server rand)",
219 3 : data->rand_s, EAP_SAKE_RAND_LEN);
220 :
221 3 : if (random_get_bytes(data->rand_p, EAP_SAKE_RAND_LEN)) {
222 0 : wpa_printf(MSG_ERROR, "EAP-SAKE: Failed to get random data");
223 0 : return NULL;
224 : }
225 3 : wpa_hexdump(MSG_MSGDUMP, "EAP-SAKE: RAND_P (peer rand)",
226 3 : data->rand_p, EAP_SAKE_RAND_LEN);
227 :
228 3 : os_free(data->serverid);
229 3 : data->serverid = NULL;
230 3 : data->serverid_len = 0;
231 3 : if (attr.serverid) {
232 6 : wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-SAKE: SERVERID",
233 3 : attr.serverid, attr.serverid_len);
234 3 : data->serverid = os_malloc(attr.serverid_len);
235 3 : if (data->serverid == NULL)
236 0 : return NULL;
237 3 : os_memcpy(data->serverid, attr.serverid, attr.serverid_len);
238 3 : data->serverid_len = attr.serverid_len;
239 : }
240 :
241 3 : eap_sake_derive_keys(data->root_secret_a, data->root_secret_b,
242 3 : data->rand_s, data->rand_p,
243 3 : (u8 *) &data->tek, data->msk, data->emsk);
244 :
245 3 : wpa_printf(MSG_DEBUG, "EAP-SAKE: Sending Response/Challenge");
246 :
247 3 : rlen = 2 + EAP_SAKE_RAND_LEN + 2 + EAP_SAKE_MIC_LEN;
248 3 : if (data->peerid)
249 3 : rlen += 2 + data->peerid_len;
250 3 : resp = eap_sake_build_msg(data, eap_get_id(reqData), rlen,
251 : EAP_SAKE_SUBTYPE_CHALLENGE);
252 3 : if (resp == NULL)
253 0 : return NULL;
254 :
255 3 : wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_RAND_P");
256 3 : eap_sake_add_attr(resp, EAP_SAKE_AT_RAND_P,
257 3 : data->rand_p, EAP_SAKE_RAND_LEN);
258 :
259 3 : if (data->peerid) {
260 3 : wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_PEERID");
261 6 : eap_sake_add_attr(resp, EAP_SAKE_AT_PEERID,
262 3 : data->peerid, data->peerid_len);
263 : }
264 :
265 3 : wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_MIC_P");
266 3 : wpabuf_put_u8(resp, EAP_SAKE_AT_MIC_P);
267 3 : wpabuf_put_u8(resp, 2 + EAP_SAKE_MIC_LEN);
268 3 : rpos = wpabuf_put(resp, EAP_SAKE_MIC_LEN);
269 12 : if (eap_sake_compute_mic(data->tek.auth, data->rand_s, data->rand_p,
270 3 : data->serverid, data->serverid_len,
271 3 : data->peerid, data->peerid_len, 1,
272 3 : wpabuf_head(resp), wpabuf_len(resp), rpos,
273 : rpos)) {
274 0 : wpa_printf(MSG_INFO, "EAP-SAKE: Failed to compute MIC");
275 0 : wpabuf_free(resp);
276 0 : return NULL;
277 : }
278 :
279 3 : eap_sake_state(data, CONFIRM);
280 :
281 3 : return resp;
282 : }
283 :
284 :
285 2 : static struct wpabuf * eap_sake_process_confirm(struct eap_sm *sm,
286 : struct eap_sake_data *data,
287 : struct eap_method_ret *ret,
288 : const struct wpabuf *reqData,
289 : const u8 *payload,
290 : size_t payload_len)
291 : {
292 : struct eap_sake_parse_attr attr;
293 : u8 mic_s[EAP_SAKE_MIC_LEN];
294 : struct wpabuf *resp;
295 : u8 *rpos;
296 :
297 2 : if (data->state != CONFIRM) {
298 0 : ret->ignore = TRUE;
299 0 : return NULL;
300 : }
301 :
302 2 : wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Request/Confirm");
303 :
304 2 : if (eap_sake_parse_attributes(payload, payload_len, &attr))
305 0 : return NULL;
306 :
307 2 : if (!attr.mic_s) {
308 0 : wpa_printf(MSG_INFO, "EAP-SAKE: Request/Confirm did not "
309 : "include AT_MIC_S");
310 0 : return NULL;
311 : }
312 :
313 8 : eap_sake_compute_mic(data->tek.auth, data->rand_s, data->rand_p,
314 2 : data->serverid, data->serverid_len,
315 2 : data->peerid, data->peerid_len, 0,
316 2 : wpabuf_head(reqData), wpabuf_len(reqData),
317 : attr.mic_s, mic_s);
318 2 : if (os_memcmp(attr.mic_s, mic_s, EAP_SAKE_MIC_LEN) != 0) {
319 0 : wpa_printf(MSG_INFO, "EAP-SAKE: Incorrect AT_MIC_S");
320 0 : eap_sake_state(data, FAILURE);
321 0 : ret->methodState = METHOD_DONE;
322 0 : ret->decision = DECISION_FAIL;
323 0 : ret->allowNotifications = FALSE;
324 0 : wpa_printf(MSG_DEBUG, "EAP-SAKE: Sending "
325 : "Response/Auth-Reject");
326 0 : return eap_sake_build_msg(data, eap_get_id(reqData), 0,
327 : EAP_SAKE_SUBTYPE_AUTH_REJECT);
328 : }
329 :
330 2 : wpa_printf(MSG_DEBUG, "EAP-SAKE: Sending Response/Confirm");
331 :
332 2 : resp = eap_sake_build_msg(data, eap_get_id(reqData),
333 : 2 + EAP_SAKE_MIC_LEN,
334 : EAP_SAKE_SUBTYPE_CONFIRM);
335 2 : if (resp == NULL)
336 0 : return NULL;
337 :
338 2 : wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_MIC_P");
339 2 : wpabuf_put_u8(resp, EAP_SAKE_AT_MIC_P);
340 2 : wpabuf_put_u8(resp, 2 + EAP_SAKE_MIC_LEN);
341 2 : rpos = wpabuf_put(resp, EAP_SAKE_MIC_LEN);
342 8 : if (eap_sake_compute_mic(data->tek.auth, data->rand_s, data->rand_p,
343 2 : data->serverid, data->serverid_len,
344 2 : data->peerid, data->peerid_len, 1,
345 2 : wpabuf_head(resp), wpabuf_len(resp), rpos,
346 : rpos)) {
347 0 : wpa_printf(MSG_INFO, "EAP-SAKE: Failed to compute MIC");
348 0 : wpabuf_free(resp);
349 0 : return NULL;
350 : }
351 :
352 2 : eap_sake_state(data, SUCCESS);
353 2 : ret->methodState = METHOD_DONE;
354 2 : ret->decision = DECISION_UNCOND_SUCC;
355 2 : ret->allowNotifications = FALSE;
356 :
357 2 : return resp;
358 : }
359 :
360 :
361 5 : static struct wpabuf * eap_sake_process(struct eap_sm *sm, void *priv,
362 : struct eap_method_ret *ret,
363 : const struct wpabuf *reqData)
364 : {
365 5 : struct eap_sake_data *data = priv;
366 : const struct eap_sake_hdr *req;
367 : struct wpabuf *resp;
368 : const u8 *pos, *end;
369 : size_t len;
370 : u8 subtype, session_id;
371 :
372 5 : pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SAKE, reqData, &len);
373 5 : if (pos == NULL || len < sizeof(struct eap_sake_hdr)) {
374 0 : ret->ignore = TRUE;
375 0 : return NULL;
376 : }
377 :
378 5 : req = (const struct eap_sake_hdr *) pos;
379 5 : end = pos + len;
380 5 : subtype = req->subtype;
381 5 : session_id = req->session_id;
382 5 : pos = (const u8 *) (req + 1);
383 :
384 5 : wpa_printf(MSG_DEBUG, "EAP-SAKE: Received frame: subtype %d "
385 : "session_id %d", subtype, session_id);
386 5 : wpa_hexdump(MSG_DEBUG, "EAP-SAKE: Received attributes",
387 5 : pos, end - pos);
388 :
389 5 : if (data->session_id_set && data->session_id != session_id) {
390 0 : wpa_printf(MSG_INFO, "EAP-SAKE: Session ID mismatch (%d,%d)",
391 0 : session_id, data->session_id);
392 0 : ret->ignore = TRUE;
393 0 : return NULL;
394 : }
395 5 : data->session_id = session_id;
396 5 : data->session_id_set = 1;
397 :
398 5 : ret->ignore = FALSE;
399 5 : ret->methodState = METHOD_MAY_CONT;
400 5 : ret->decision = DECISION_FAIL;
401 5 : ret->allowNotifications = TRUE;
402 :
403 5 : switch (subtype) {
404 : case EAP_SAKE_SUBTYPE_IDENTITY:
405 0 : resp = eap_sake_process_identity(sm, data, ret, reqData,
406 0 : pos, end - pos);
407 0 : break;
408 : case EAP_SAKE_SUBTYPE_CHALLENGE:
409 3 : resp = eap_sake_process_challenge(sm, data, ret, reqData,
410 3 : pos, end - pos);
411 3 : break;
412 : case EAP_SAKE_SUBTYPE_CONFIRM:
413 2 : resp = eap_sake_process_confirm(sm, data, ret, reqData,
414 2 : pos, end - pos);
415 2 : break;
416 : default:
417 0 : wpa_printf(MSG_DEBUG, "EAP-SAKE: Ignoring message with "
418 : "unknown subtype %d", subtype);
419 0 : ret->ignore = TRUE;
420 0 : return NULL;
421 : }
422 :
423 5 : if (ret->methodState == METHOD_DONE)
424 2 : ret->allowNotifications = FALSE;
425 :
426 5 : return resp;
427 : }
428 :
429 :
430 5 : static Boolean eap_sake_isKeyAvailable(struct eap_sm *sm, void *priv)
431 : {
432 5 : struct eap_sake_data *data = priv;
433 5 : return data->state == SUCCESS;
434 : }
435 :
436 :
437 2 : static u8 * eap_sake_getKey(struct eap_sm *sm, void *priv, size_t *len)
438 : {
439 2 : struct eap_sake_data *data = priv;
440 : u8 *key;
441 :
442 2 : if (data->state != SUCCESS)
443 0 : return NULL;
444 :
445 2 : key = os_malloc(EAP_MSK_LEN);
446 2 : if (key == NULL)
447 0 : return NULL;
448 2 : os_memcpy(key, data->msk, EAP_MSK_LEN);
449 2 : *len = EAP_MSK_LEN;
450 :
451 2 : return key;
452 : }
453 :
454 :
455 2 : static u8 * eap_sake_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
456 : {
457 2 : struct eap_sake_data *data = priv;
458 : u8 *id;
459 :
460 2 : if (data->state != SUCCESS)
461 0 : return NULL;
462 :
463 2 : *len = 1 + 2 * EAP_SAKE_RAND_LEN;
464 2 : id = os_malloc(*len);
465 2 : if (id == NULL)
466 0 : return NULL;
467 :
468 2 : id[0] = EAP_TYPE_SAKE;
469 2 : os_memcpy(id + 1, data->rand_s, EAP_SAKE_RAND_LEN);
470 2 : os_memcpy(id + 1 + EAP_SAKE_RAND_LEN, data->rand_s, EAP_SAKE_RAND_LEN);
471 2 : wpa_hexdump(MSG_DEBUG, "EAP-SAKE: Derived Session-Id", id, *len);
472 :
473 2 : return id;
474 : }
475 :
476 :
477 0 : static u8 * eap_sake_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
478 : {
479 0 : struct eap_sake_data *data = priv;
480 : u8 *key;
481 :
482 0 : if (data->state != SUCCESS)
483 0 : return NULL;
484 :
485 0 : key = os_malloc(EAP_EMSK_LEN);
486 0 : if (key == NULL)
487 0 : return NULL;
488 0 : os_memcpy(key, data->emsk, EAP_EMSK_LEN);
489 0 : *len = EAP_EMSK_LEN;
490 :
491 0 : return key;
492 : }
493 :
494 :
495 4 : int eap_peer_sake_register(void)
496 : {
497 : struct eap_method *eap;
498 : int ret;
499 :
500 4 : eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
501 : EAP_VENDOR_IETF, EAP_TYPE_SAKE, "SAKE");
502 4 : if (eap == NULL)
503 0 : return -1;
504 :
505 4 : eap->init = eap_sake_init;
506 4 : eap->deinit = eap_sake_deinit;
507 4 : eap->process = eap_sake_process;
508 4 : eap->isKeyAvailable = eap_sake_isKeyAvailable;
509 4 : eap->getKey = eap_sake_getKey;
510 4 : eap->getSessionId = eap_sake_get_session_id;
511 4 : eap->get_emsk = eap_sake_get_emsk;
512 :
513 4 : ret = eap_peer_method_register(eap);
514 4 : if (ret)
515 0 : eap_peer_method_free(eap);
516 4 : return ret;
517 : }
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