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 50 : static const char * eap_sake_state_txt(int state)
38 : {
39 50 : switch (state) {
40 : case IDENTITY:
41 12 : return "IDENTITY";
42 : case CHALLENGE:
43 21 : return "CHALLENGE";
44 : case CONFIRM:
45 13 : return "CONFIRM";
46 : case SUCCESS:
47 3 : return "SUCCESS";
48 : case FAILURE:
49 1 : return "FAILURE";
50 : default:
51 0 : return "?";
52 : }
53 : }
54 :
55 :
56 25 : static void eap_sake_state(struct eap_sake_data *data, int state)
57 : {
58 50 : wpa_printf(MSG_DEBUG, "EAP-SAKE: %s -> %s",
59 25 : eap_sake_state_txt(data->state),
60 : eap_sake_state_txt(state));
61 25 : data->state = state;
62 25 : }
63 :
64 :
65 : static void eap_sake_deinit(struct eap_sm *sm, void *priv);
66 :
67 :
68 29 : 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 29 : password = eap_get_config_password(sm, &password_len);
75 29 : if (!password || password_len != 2 * EAP_SAKE_ROOT_SECRET_LEN) {
76 11 : wpa_printf(MSG_INFO, "EAP-SAKE: No key of correct length "
77 : "configured");
78 11 : return NULL;
79 : }
80 :
81 18 : data = os_zalloc(sizeof(*data));
82 18 : if (data == NULL)
83 0 : return NULL;
84 18 : data->state = IDENTITY;
85 :
86 18 : identity = eap_get_config_identity(sm, &identity_len);
87 18 : if (identity) {
88 18 : data->peerid = os_malloc(identity_len);
89 18 : if (data->peerid == NULL) {
90 0 : eap_sake_deinit(sm, data);
91 0 : return NULL;
92 : }
93 18 : os_memcpy(data->peerid, identity, identity_len);
94 18 : data->peerid_len = identity_len;
95 : }
96 :
97 18 : os_memcpy(data->root_secret_a, password, EAP_SAKE_ROOT_SECRET_LEN);
98 18 : os_memcpy(data->root_secret_b,
99 : password + EAP_SAKE_ROOT_SECRET_LEN,
100 : EAP_SAKE_ROOT_SECRET_LEN);
101 :
102 18 : return data;
103 : }
104 :
105 :
106 18 : static void eap_sake_deinit(struct eap_sm *sm, void *priv)
107 : {
108 18 : struct eap_sake_data *data = priv;
109 18 : os_free(data->serverid);
110 18 : os_free(data->peerid);
111 18 : bin_clear_free(data, sizeof(*data));
112 18 : }
113 :
114 :
115 14 : 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 14 : plen = length + sizeof(struct eap_sake_hdr);
123 :
124 14 : msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_SAKE, plen,
125 : EAP_CODE_RESPONSE, id);
126 14 : if (msg == NULL) {
127 0 : wpa_printf(MSG_ERROR, "EAP-SAKE: Failed to allocate memory "
128 : "request");
129 0 : return NULL;
130 : }
131 :
132 14 : sake = wpabuf_put(msg, sizeof(*sake));
133 14 : sake->version = EAP_SAKE_VERSION;
134 14 : sake->session_id = data->session_id;
135 14 : sake->subtype = subtype;
136 :
137 14 : return msg;
138 : }
139 :
140 :
141 5 : static struct wpabuf * eap_sake_process_identity(struct eap_sm *sm,
142 : struct eap_sake_data *data,
143 : struct eap_method_ret *ret,
144 : u8 id,
145 : const u8 *payload,
146 : size_t payload_len)
147 : {
148 : struct eap_sake_parse_attr attr;
149 : struct wpabuf *resp;
150 :
151 5 : if (data->state != IDENTITY) {
152 1 : ret->ignore = TRUE;
153 1 : return NULL;
154 : }
155 :
156 4 : wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Request/Identity");
157 :
158 4 : if (eap_sake_parse_attributes(payload, payload_len, &attr))
159 2 : return NULL;
160 :
161 2 : if (!attr.perm_id_req && !attr.any_id_req) {
162 1 : wpa_printf(MSG_INFO, "EAP-SAKE: No AT_PERM_ID_REQ or "
163 : "AT_ANY_ID_REQ in Request/Identity");
164 1 : return NULL;
165 : }
166 :
167 1 : wpa_printf(MSG_DEBUG, "EAP-SAKE: Sending Response/Identity");
168 :
169 1 : resp = eap_sake_build_msg(data, id, 2 + data->peerid_len,
170 : EAP_SAKE_SUBTYPE_IDENTITY);
171 1 : if (resp == NULL)
172 0 : return NULL;
173 :
174 1 : wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_PEERID");
175 2 : eap_sake_add_attr(resp, EAP_SAKE_AT_PEERID,
176 1 : data->peerid, data->peerid_len);
177 :
178 1 : eap_sake_state(data, CHALLENGE);
179 :
180 1 : return resp;
181 : }
182 :
183 :
184 12 : static struct wpabuf * eap_sake_process_challenge(struct eap_sm *sm,
185 : struct eap_sake_data *data,
186 : struct eap_method_ret *ret,
187 : u8 id,
188 : const u8 *payload,
189 : size_t payload_len)
190 : {
191 : struct eap_sake_parse_attr attr;
192 : struct wpabuf *resp;
193 : u8 *rpos;
194 : size_t rlen;
195 :
196 12 : if (data->state != IDENTITY && data->state != CHALLENGE) {
197 1 : wpa_printf(MSG_DEBUG, "EAP-SAKE: Request/Challenge received "
198 1 : "in unexpected state (%d)", data->state);
199 1 : ret->ignore = TRUE;
200 1 : return NULL;
201 : }
202 11 : if (data->state == IDENTITY)
203 11 : eap_sake_state(data, CHALLENGE);
204 :
205 11 : wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Request/Challenge");
206 :
207 11 : if (eap_sake_parse_attributes(payload, payload_len, &attr))
208 1 : return NULL;
209 :
210 10 : if (!attr.rand_s) {
211 1 : wpa_printf(MSG_INFO, "EAP-SAKE: Request/Challenge did not "
212 : "include AT_RAND_S");
213 1 : return NULL;
214 : }
215 :
216 9 : os_memcpy(data->rand_s, attr.rand_s, EAP_SAKE_RAND_LEN);
217 9 : wpa_hexdump(MSG_MSGDUMP, "EAP-SAKE: RAND_S (server rand)",
218 9 : data->rand_s, EAP_SAKE_RAND_LEN);
219 :
220 9 : if (random_get_bytes(data->rand_p, EAP_SAKE_RAND_LEN)) {
221 0 : wpa_printf(MSG_ERROR, "EAP-SAKE: Failed to get random data");
222 0 : return NULL;
223 : }
224 9 : wpa_hexdump(MSG_MSGDUMP, "EAP-SAKE: RAND_P (peer rand)",
225 9 : data->rand_p, EAP_SAKE_RAND_LEN);
226 :
227 9 : os_free(data->serverid);
228 9 : data->serverid = NULL;
229 9 : data->serverid_len = 0;
230 9 : if (attr.serverid) {
231 8 : wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-SAKE: SERVERID",
232 4 : attr.serverid, attr.serverid_len);
233 4 : data->serverid = os_malloc(attr.serverid_len);
234 4 : if (data->serverid == NULL)
235 0 : return NULL;
236 4 : os_memcpy(data->serverid, attr.serverid, attr.serverid_len);
237 4 : data->serverid_len = attr.serverid_len;
238 : }
239 :
240 9 : eap_sake_derive_keys(data->root_secret_a, data->root_secret_b,
241 9 : data->rand_s, data->rand_p,
242 9 : (u8 *) &data->tek, data->msk, data->emsk);
243 :
244 9 : wpa_printf(MSG_DEBUG, "EAP-SAKE: Sending Response/Challenge");
245 :
246 9 : rlen = 2 + EAP_SAKE_RAND_LEN + 2 + EAP_SAKE_MIC_LEN;
247 9 : if (data->peerid)
248 9 : rlen += 2 + data->peerid_len;
249 9 : resp = eap_sake_build_msg(data, id, rlen, EAP_SAKE_SUBTYPE_CHALLENGE);
250 9 : if (resp == NULL)
251 0 : return NULL;
252 :
253 9 : wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_RAND_P");
254 9 : eap_sake_add_attr(resp, EAP_SAKE_AT_RAND_P,
255 9 : data->rand_p, EAP_SAKE_RAND_LEN);
256 :
257 9 : if (data->peerid) {
258 9 : wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_PEERID");
259 18 : eap_sake_add_attr(resp, EAP_SAKE_AT_PEERID,
260 9 : data->peerid, data->peerid_len);
261 : }
262 :
263 9 : wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_MIC_P");
264 9 : wpabuf_put_u8(resp, EAP_SAKE_AT_MIC_P);
265 9 : wpabuf_put_u8(resp, 2 + EAP_SAKE_MIC_LEN);
266 9 : rpos = wpabuf_put(resp, EAP_SAKE_MIC_LEN);
267 36 : if (eap_sake_compute_mic(data->tek.auth, data->rand_s, data->rand_p,
268 9 : data->serverid, data->serverid_len,
269 9 : data->peerid, data->peerid_len, 1,
270 9 : wpabuf_head(resp), wpabuf_len(resp), rpos,
271 : rpos)) {
272 0 : wpa_printf(MSG_INFO, "EAP-SAKE: Failed to compute MIC");
273 0 : wpabuf_free(resp);
274 0 : return NULL;
275 : }
276 :
277 9 : eap_sake_state(data, CONFIRM);
278 :
279 9 : return resp;
280 : }
281 :
282 :
283 7 : static struct wpabuf * eap_sake_process_confirm(struct eap_sm *sm,
284 : struct eap_sake_data *data,
285 : struct eap_method_ret *ret,
286 : u8 id,
287 : const struct wpabuf *reqData,
288 : const u8 *payload,
289 : size_t payload_len)
290 : {
291 : struct eap_sake_parse_attr attr;
292 : u8 mic_s[EAP_SAKE_MIC_LEN];
293 : struct wpabuf *resp;
294 : u8 *rpos;
295 :
296 7 : if (data->state != CONFIRM) {
297 1 : ret->ignore = TRUE;
298 1 : return NULL;
299 : }
300 :
301 6 : wpa_printf(MSG_DEBUG, "EAP-SAKE: Received Request/Confirm");
302 :
303 6 : if (eap_sake_parse_attributes(payload, payload_len, &attr))
304 1 : return NULL;
305 :
306 5 : if (!attr.mic_s) {
307 1 : wpa_printf(MSG_INFO, "EAP-SAKE: Request/Confirm did not "
308 : "include AT_MIC_S");
309 1 : return NULL;
310 : }
311 :
312 16 : eap_sake_compute_mic(data->tek.auth, data->rand_s, data->rand_p,
313 4 : data->serverid, data->serverid_len,
314 4 : data->peerid, data->peerid_len, 0,
315 4 : wpabuf_head(reqData), wpabuf_len(reqData),
316 : attr.mic_s, mic_s);
317 4 : if (os_memcmp_const(attr.mic_s, mic_s, EAP_SAKE_MIC_LEN) != 0) {
318 1 : wpa_printf(MSG_INFO, "EAP-SAKE: Incorrect AT_MIC_S");
319 1 : eap_sake_state(data, FAILURE);
320 1 : ret->methodState = METHOD_DONE;
321 1 : ret->decision = DECISION_FAIL;
322 1 : ret->allowNotifications = FALSE;
323 1 : wpa_printf(MSG_DEBUG, "EAP-SAKE: Sending "
324 : "Response/Auth-Reject");
325 1 : return eap_sake_build_msg(data, id, 0,
326 : EAP_SAKE_SUBTYPE_AUTH_REJECT);
327 : }
328 :
329 3 : wpa_printf(MSG_DEBUG, "EAP-SAKE: Sending Response/Confirm");
330 :
331 3 : resp = eap_sake_build_msg(data, id, 2 + EAP_SAKE_MIC_LEN,
332 : EAP_SAKE_SUBTYPE_CONFIRM);
333 3 : if (resp == NULL)
334 0 : return NULL;
335 :
336 3 : wpa_printf(MSG_DEBUG, "EAP-SAKE: * AT_MIC_P");
337 3 : wpabuf_put_u8(resp, EAP_SAKE_AT_MIC_P);
338 3 : wpabuf_put_u8(resp, 2 + EAP_SAKE_MIC_LEN);
339 3 : rpos = wpabuf_put(resp, EAP_SAKE_MIC_LEN);
340 12 : if (eap_sake_compute_mic(data->tek.auth, data->rand_s, data->rand_p,
341 3 : data->serverid, data->serverid_len,
342 3 : data->peerid, data->peerid_len, 1,
343 3 : wpabuf_head(resp), wpabuf_len(resp), rpos,
344 : rpos)) {
345 0 : wpa_printf(MSG_INFO, "EAP-SAKE: Failed to compute MIC");
346 0 : wpabuf_free(resp);
347 0 : return NULL;
348 : }
349 :
350 3 : eap_sake_state(data, SUCCESS);
351 3 : ret->methodState = METHOD_DONE;
352 3 : ret->decision = DECISION_UNCOND_SUCC;
353 3 : ret->allowNotifications = FALSE;
354 :
355 3 : return resp;
356 : }
357 :
358 :
359 27 : static struct wpabuf * eap_sake_process(struct eap_sm *sm, void *priv,
360 : struct eap_method_ret *ret,
361 : const struct wpabuf *reqData)
362 : {
363 27 : struct eap_sake_data *data = priv;
364 : const struct eap_sake_hdr *req;
365 : struct wpabuf *resp;
366 : const u8 *pos, *end;
367 : size_t len;
368 : u8 subtype, session_id, id;
369 :
370 27 : pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SAKE, reqData, &len);
371 27 : if (pos == NULL || len < sizeof(struct eap_sake_hdr)) {
372 1 : ret->ignore = TRUE;
373 1 : return NULL;
374 : }
375 :
376 26 : req = (const struct eap_sake_hdr *) pos;
377 26 : end = pos + len;
378 26 : id = eap_get_id(reqData);
379 26 : subtype = req->subtype;
380 26 : session_id = req->session_id;
381 26 : pos = (const u8 *) (req + 1);
382 :
383 26 : wpa_printf(MSG_DEBUG, "EAP-SAKE: Received frame: subtype %d "
384 : "session_id %d", subtype, session_id);
385 26 : wpa_hexdump(MSG_DEBUG, "EAP-SAKE: Received attributes",
386 26 : pos, end - pos);
387 :
388 26 : if (data->session_id_set && data->session_id != session_id) {
389 1 : wpa_printf(MSG_INFO, "EAP-SAKE: Session ID mismatch (%d,%d)",
390 1 : session_id, data->session_id);
391 1 : ret->ignore = TRUE;
392 1 : return NULL;
393 : }
394 25 : data->session_id = session_id;
395 25 : data->session_id_set = 1;
396 :
397 25 : ret->ignore = FALSE;
398 25 : ret->methodState = METHOD_MAY_CONT;
399 25 : ret->decision = DECISION_FAIL;
400 25 : ret->allowNotifications = TRUE;
401 :
402 25 : switch (subtype) {
403 : case EAP_SAKE_SUBTYPE_IDENTITY:
404 5 : resp = eap_sake_process_identity(sm, data, ret, id,
405 5 : pos, end - pos);
406 5 : break;
407 : case EAP_SAKE_SUBTYPE_CHALLENGE:
408 12 : resp = eap_sake_process_challenge(sm, data, ret, id,
409 12 : pos, end - pos);
410 12 : break;
411 : case EAP_SAKE_SUBTYPE_CONFIRM:
412 7 : resp = eap_sake_process_confirm(sm, data, ret, id, reqData,
413 7 : pos, end - pos);
414 7 : break;
415 : default:
416 1 : wpa_printf(MSG_DEBUG, "EAP-SAKE: Ignoring message with "
417 : "unknown subtype %d", subtype);
418 1 : ret->ignore = TRUE;
419 1 : return NULL;
420 : }
421 :
422 24 : if (ret->methodState == METHOD_DONE)
423 4 : ret->allowNotifications = FALSE;
424 :
425 24 : return resp;
426 : }
427 :
428 :
429 21 : static Boolean eap_sake_isKeyAvailable(struct eap_sm *sm, void *priv)
430 : {
431 21 : struct eap_sake_data *data = priv;
432 21 : return data->state == SUCCESS;
433 : }
434 :
435 :
436 3 : static u8 * eap_sake_getKey(struct eap_sm *sm, void *priv, size_t *len)
437 : {
438 3 : struct eap_sake_data *data = priv;
439 : u8 *key;
440 :
441 3 : if (data->state != SUCCESS)
442 0 : return NULL;
443 :
444 3 : key = os_malloc(EAP_MSK_LEN);
445 3 : if (key == NULL)
446 0 : return NULL;
447 3 : os_memcpy(key, data->msk, EAP_MSK_LEN);
448 3 : *len = EAP_MSK_LEN;
449 :
450 3 : return key;
451 : }
452 :
453 :
454 3 : static u8 * eap_sake_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
455 : {
456 3 : struct eap_sake_data *data = priv;
457 : u8 *id;
458 :
459 3 : if (data->state != SUCCESS)
460 0 : return NULL;
461 :
462 3 : *len = 1 + 2 * EAP_SAKE_RAND_LEN;
463 3 : id = os_malloc(*len);
464 3 : if (id == NULL)
465 0 : return NULL;
466 :
467 3 : id[0] = EAP_TYPE_SAKE;
468 3 : os_memcpy(id + 1, data->rand_s, EAP_SAKE_RAND_LEN);
469 3 : os_memcpy(id + 1 + EAP_SAKE_RAND_LEN, data->rand_s, EAP_SAKE_RAND_LEN);
470 3 : wpa_hexdump(MSG_DEBUG, "EAP-SAKE: Derived Session-Id", id, *len);
471 :
472 3 : return id;
473 : }
474 :
475 :
476 1 : static u8 * eap_sake_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
477 : {
478 1 : struct eap_sake_data *data = priv;
479 : u8 *key;
480 :
481 1 : if (data->state != SUCCESS)
482 0 : return NULL;
483 :
484 1 : key = os_malloc(EAP_EMSK_LEN);
485 1 : if (key == NULL)
486 0 : return NULL;
487 1 : os_memcpy(key, data->emsk, EAP_EMSK_LEN);
488 1 : *len = EAP_EMSK_LEN;
489 :
490 1 : return key;
491 : }
492 :
493 :
494 49 : int eap_peer_sake_register(void)
495 : {
496 : struct eap_method *eap;
497 : int ret;
498 :
499 49 : eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
500 : EAP_VENDOR_IETF, EAP_TYPE_SAKE, "SAKE");
501 49 : if (eap == NULL)
502 0 : return -1;
503 :
504 49 : eap->init = eap_sake_init;
505 49 : eap->deinit = eap_sake_deinit;
506 49 : eap->process = eap_sake_process;
507 49 : eap->isKeyAvailable = eap_sake_isKeyAvailable;
508 49 : eap->getKey = eap_sake_getKey;
509 49 : eap->getSessionId = eap_sake_get_session_id;
510 49 : eap->get_emsk = eap_sake_get_emsk;
511 :
512 49 : ret = eap_peer_method_register(eap);
513 49 : if (ret)
514 0 : eap_peer_method_free(eap);
515 49 : return ret;
516 : }
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