1 /*
2 * EAP peer method: EAP-EKE (RFC 6124)
3 * Copyright (c) 2013, 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_eke_common.h"
15
16 struct eap_eke_data {
17 enum {
18 IDENTITY, COMMIT, CONFIRM, SUCCESS, FAILURE
19 } state;
20 u8 msk[EAP_MSK_LEN];
21 u8 emsk[EAP_EMSK_LEN];
22 u8 *peerid;
23 size_t peerid_len;
24 u8 *serverid;
25 size_t serverid_len;
26 u8 dh_priv[EAP_EKE_MAX_DH_LEN];
27 struct eap_eke_session sess;
28 u8 nonce_p[EAP_EKE_MAX_NONCE_LEN];
29 u8 nonce_s[EAP_EKE_MAX_NONCE_LEN];
30 struct wpabuf *msgs;
31 u8 dhgroup; /* forced DH group or 0 to allow all supported */
32 u8 encr; /* forced encryption algorithm or 0 to allow all supported */
33 u8 prf; /* forced PRF or 0 to allow all supported */
34 u8 mac; /* forced MAC or 0 to allow all supported */
35 };
36
37
eap_eke_state_txt(int state)38 static const char * eap_eke_state_txt(int state)
39 {
40 switch (state) {
41 case IDENTITY:
42 return "IDENTITY";
43 case COMMIT:
44 return "COMMIT";
45 case CONFIRM:
46 return "CONFIRM";
47 case SUCCESS:
48 return "SUCCESS";
49 case FAILURE:
50 return "FAILURE";
51 default:
52 return "?";
53 }
54 }
55
56
eap_eke_state(struct eap_eke_data * data,int state)57 static void eap_eke_state(struct eap_eke_data *data, int state)
58 {
59 wpa_printf(MSG_DEBUG, "EAP-EKE: %s -> %s",
60 eap_eke_state_txt(data->state), eap_eke_state_txt(state));
61 data->state = state;
62 }
63
64
65 static void eap_eke_deinit(struct eap_sm *sm, void *priv);
66
67
eap_eke_init(struct eap_sm * sm)68 static void * eap_eke_init(struct eap_sm *sm)
69 {
70 struct eap_eke_data *data;
71 const u8 *identity, *password;
72 size_t identity_len, password_len;
73 const char *phase1;
74
75 password = eap_get_config_password(sm, &password_len);
76 if (!password) {
77 wpa_printf(MSG_INFO, "EAP-EKE: No password configured");
78 return NULL;
79 }
80
81 data = os_zalloc(sizeof(*data));
82 if (data == NULL)
83 return NULL;
84 eap_eke_state(data, IDENTITY);
85
86 identity = eap_get_config_identity(sm, &identity_len);
87 if (identity) {
88 data->peerid = os_malloc(identity_len);
89 if (data->peerid == NULL) {
90 eap_eke_deinit(sm, data);
91 return NULL;
92 }
93 os_memcpy(data->peerid, identity, identity_len);
94 data->peerid_len = identity_len;
95 }
96
97 phase1 = eap_get_config_phase1(sm);
98 if (phase1) {
99 const char *pos;
100
101 pos = os_strstr(phase1, "dhgroup=");
102 if (pos) {
103 data->dhgroup = atoi(pos + 8);
104 wpa_printf(MSG_DEBUG, "EAP-EKE: Forced dhgroup %u",
105 data->dhgroup);
106 }
107
108 pos = os_strstr(phase1, "encr=");
109 if (pos) {
110 data->encr = atoi(pos + 5);
111 wpa_printf(MSG_DEBUG, "EAP-EKE: Forced encr %u",
112 data->encr);
113 }
114
115 pos = os_strstr(phase1, "prf=");
116 if (pos) {
117 data->prf = atoi(pos + 4);
118 wpa_printf(MSG_DEBUG, "EAP-EKE: Forced prf %u",
119 data->prf);
120 }
121
122 pos = os_strstr(phase1, "mac=");
123 if (pos) {
124 data->mac = atoi(pos + 4);
125 wpa_printf(MSG_DEBUG, "EAP-EKE: Forced mac %u",
126 data->mac);
127 }
128 }
129
130 return data;
131 }
132
133
eap_eke_deinit(struct eap_sm * sm,void * priv)134 static void eap_eke_deinit(struct eap_sm *sm, void *priv)
135 {
136 struct eap_eke_data *data = priv;
137 eap_eke_session_clean(&data->sess);
138 os_free(data->serverid);
139 os_free(data->peerid);
140 wpabuf_free(data->msgs);
141 bin_clear_free(data, sizeof(*data));
142 }
143
144
eap_eke_build_msg(struct eap_eke_data * data,int id,size_t length,u8 eke_exch)145 static struct wpabuf * eap_eke_build_msg(struct eap_eke_data *data, int id,
146 size_t length, u8 eke_exch)
147 {
148 struct wpabuf *msg;
149 size_t plen;
150
151 plen = 1 + length;
152
153 msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_EKE, plen,
154 EAP_CODE_RESPONSE, id);
155 if (msg == NULL) {
156 wpa_printf(MSG_ERROR, "EAP-EKE: Failed to allocate memory");
157 return NULL;
158 }
159
160 wpabuf_put_u8(msg, eke_exch);
161
162 return msg;
163 }
164
165
eap_eke_supp_dhgroup(u8 dhgroup)166 static int eap_eke_supp_dhgroup(u8 dhgroup)
167 {
168 return dhgroup == EAP_EKE_DHGROUP_EKE_2 ||
169 dhgroup == EAP_EKE_DHGROUP_EKE_5 ||
170 dhgroup == EAP_EKE_DHGROUP_EKE_14 ||
171 dhgroup == EAP_EKE_DHGROUP_EKE_15 ||
172 dhgroup == EAP_EKE_DHGROUP_EKE_16;
173 }
174
175
eap_eke_supp_encr(u8 encr)176 static int eap_eke_supp_encr(u8 encr)
177 {
178 return encr == EAP_EKE_ENCR_AES128_CBC;
179 }
180
181
eap_eke_supp_prf(u8 prf)182 static int eap_eke_supp_prf(u8 prf)
183 {
184 return prf == EAP_EKE_PRF_HMAC_SHA1 ||
185 prf == EAP_EKE_PRF_HMAC_SHA2_256;
186 }
187
188
eap_eke_supp_mac(u8 mac)189 static int eap_eke_supp_mac(u8 mac)
190 {
191 return mac == EAP_EKE_MAC_HMAC_SHA1 ||
192 mac == EAP_EKE_MAC_HMAC_SHA2_256;
193 }
194
195
eap_eke_build_fail(struct eap_eke_data * data,struct eap_method_ret * ret,u8 id,u32 failure_code)196 static struct wpabuf * eap_eke_build_fail(struct eap_eke_data *data,
197 struct eap_method_ret *ret,
198 u8 id, u32 failure_code)
199 {
200 struct wpabuf *resp;
201
202 wpa_printf(MSG_DEBUG, "EAP-EKE: Sending EAP-EKE-Failure/Response - code=0x%x",
203 failure_code);
204
205 resp = eap_eke_build_msg(data, id, 4, EAP_EKE_FAILURE);
206 if (resp)
207 wpabuf_put_be32(resp, failure_code);
208
209 os_memset(data->dh_priv, 0, sizeof(data->dh_priv));
210 eap_eke_session_clean(&data->sess);
211
212 eap_eke_state(data, FAILURE);
213 ret->methodState = METHOD_DONE;
214 ret->decision = DECISION_FAIL;
215 ret->allowNotifications = FALSE;
216
217 return resp;
218 }
219
220
eap_eke_process_id(struct eap_eke_data * data,struct eap_method_ret * ret,const struct wpabuf * reqData,const u8 * payload,size_t payload_len)221 static struct wpabuf * eap_eke_process_id(struct eap_eke_data *data,
222 struct eap_method_ret *ret,
223 const struct wpabuf *reqData,
224 const u8 *payload,
225 size_t payload_len)
226 {
227 struct wpabuf *resp;
228 unsigned num_prop, i;
229 const u8 *pos, *end;
230 const u8 *prop = NULL;
231 u8 idtype;
232 u8 id = eap_get_id(reqData);
233
234 if (data->state != IDENTITY) {
235 return eap_eke_build_fail(data, ret, id,
236 EAP_EKE_FAIL_PROTO_ERROR);
237 }
238
239 wpa_printf(MSG_DEBUG, "EAP-EKE: Received EAP-EKE-ID/Request");
240
241 if (payload_len < 2 + 4) {
242 wpa_printf(MSG_DEBUG, "EAP-EKE: Too short ID/Request Data");
243 return eap_eke_build_fail(data, ret, id,
244 EAP_EKE_FAIL_PROTO_ERROR);
245 }
246
247 pos = payload;
248 end = payload + payload_len;
249
250 num_prop = *pos++;
251 pos++; /* Ignore Reserved field */
252
253 if (pos + num_prop * 4 > end) {
254 wpa_printf(MSG_DEBUG, "EAP-EKE: Too short ID/Request Data (num_prop=%u)",
255 num_prop);
256 return eap_eke_build_fail(data, ret, id,
257 EAP_EKE_FAIL_PROTO_ERROR);
258 }
259
260 for (i = 0; i < num_prop; i++) {
261 const u8 *tmp = pos;
262
263 wpa_printf(MSG_DEBUG, "EAP-EKE: Proposal #%u: dh=%u encr=%u prf=%u mac=%u",
264 i, pos[0], pos[1], pos[2], pos[3]);
265 pos += 4;
266
267 if ((data->dhgroup && data->dhgroup != *tmp) ||
268 !eap_eke_supp_dhgroup(*tmp))
269 continue;
270 tmp++;
271 if ((data->encr && data->encr != *tmp) ||
272 !eap_eke_supp_encr(*tmp))
273 continue;
274 tmp++;
275 if ((data->prf && data->prf != *tmp) ||
276 !eap_eke_supp_prf(*tmp))
277 continue;
278 tmp++;
279 if ((data->mac && data->mac != *tmp) ||
280 !eap_eke_supp_mac(*tmp))
281 continue;
282
283 prop = tmp - 3;
284 if (eap_eke_session_init(&data->sess, prop[0], prop[1], prop[2],
285 prop[3]) < 0) {
286 prop = NULL;
287 continue;
288 }
289
290 wpa_printf(MSG_DEBUG, "EAP-EKE: Selected proposal");
291 break;
292 }
293
294 if (prop == NULL) {
295 wpa_printf(MSG_DEBUG, "EAP-EKE: No acceptable proposal found");
296 return eap_eke_build_fail(data, ret, id,
297 EAP_EKE_FAIL_NO_PROPOSAL_CHOSEN);
298 }
299
300 pos += (num_prop - i - 1) * 4;
301
302 if (pos == end) {
303 wpa_printf(MSG_DEBUG, "EAP-EKE: Too short ID/Request Data to include IDType/Identity");
304 return eap_eke_build_fail(data, ret, id,
305 EAP_EKE_FAIL_PROTO_ERROR);
306 }
307
308 idtype = *pos++;
309 wpa_printf(MSG_DEBUG, "EAP-EKE: Server IDType %u", idtype);
310 wpa_hexdump_ascii(MSG_DEBUG, "EAP-EKE: Server Identity",
311 pos, end - pos);
312 os_free(data->serverid);
313 data->serverid = os_malloc(end - pos);
314 if (data->serverid == NULL) {
315 return eap_eke_build_fail(data, ret, id,
316 EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
317 }
318 os_memcpy(data->serverid, pos, end - pos);
319 data->serverid_len = end - pos;
320
321 wpa_printf(MSG_DEBUG, "EAP-EKE: Sending EAP-EKE-ID/Response");
322
323 resp = eap_eke_build_msg(data, id,
324 2 + 4 + 1 + data->peerid_len,
325 EAP_EKE_ID);
326 if (resp == NULL) {
327 return eap_eke_build_fail(data, ret, id,
328 EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
329 }
330
331 wpabuf_put_u8(resp, 1); /* NumProposals */
332 wpabuf_put_u8(resp, 0); /* Reserved */
333 wpabuf_put_data(resp, prop, 4); /* Selected Proposal */
334 wpabuf_put_u8(resp, EAP_EKE_ID_NAI);
335 if (data->peerid)
336 wpabuf_put_data(resp, data->peerid, data->peerid_len);
337
338 wpabuf_free(data->msgs);
339 data->msgs = wpabuf_alloc(wpabuf_len(reqData) + wpabuf_len(resp));
340 if (data->msgs == NULL) {
341 wpabuf_free(resp);
342 return eap_eke_build_fail(data, ret, id,
343 EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
344 }
345 wpabuf_put_buf(data->msgs, reqData);
346 wpabuf_put_buf(data->msgs, resp);
347
348 eap_eke_state(data, COMMIT);
349
350 return resp;
351 }
352
353
eap_eke_process_commit(struct eap_sm * sm,struct eap_eke_data * data,struct eap_method_ret * ret,const struct wpabuf * reqData,const u8 * payload,size_t payload_len)354 static struct wpabuf * eap_eke_process_commit(struct eap_sm *sm,
355 struct eap_eke_data *data,
356 struct eap_method_ret *ret,
357 const struct wpabuf *reqData,
358 const u8 *payload,
359 size_t payload_len)
360 {
361 struct wpabuf *resp;
362 const u8 *pos, *end, *dhcomp;
363 size_t prot_len;
364 u8 *rpos;
365 u8 key[EAP_EKE_MAX_KEY_LEN];
366 u8 pub[EAP_EKE_MAX_DH_LEN];
367 const u8 *password;
368 size_t password_len;
369 u8 id = eap_get_id(reqData);
370
371 if (data->state != COMMIT) {
372 wpa_printf(MSG_DEBUG, "EAP-EKE: EAP-EKE-Commit/Request received in unexpected state (%d)", data->state);
373 return eap_eke_build_fail(data, ret, id,
374 EAP_EKE_FAIL_PROTO_ERROR);
375 }
376
377 wpa_printf(MSG_DEBUG, "EAP-EKE: Received EAP-EKE-Commit/Request");
378
379 password = eap_get_config_password(sm, &password_len);
380 if (password == NULL) {
381 wpa_printf(MSG_INFO, "EAP-EKE: No password configured!");
382 return eap_eke_build_fail(data, ret, id,
383 EAP_EKE_FAIL_PASSWD_NOT_FOUND);
384 }
385
386 pos = payload;
387 end = payload + payload_len;
388
389 if (pos + data->sess.dhcomp_len > end) {
390 wpa_printf(MSG_DEBUG, "EAP-EKE: Too short EAP-EKE-Commit");
391 return eap_eke_build_fail(data, ret, id,
392 EAP_EKE_FAIL_PROTO_ERROR);
393 }
394
395 wpa_hexdump(MSG_DEBUG, "EAP-EKE: DHComponent_S",
396 pos, data->sess.dhcomp_len);
397 dhcomp = pos;
398 pos += data->sess.dhcomp_len;
399 wpa_hexdump(MSG_DEBUG, "EAP-EKE: CBValue", pos, end - pos);
400
401 /*
402 * temp = prf(0+, password)
403 * key = prf+(temp, ID_S | ID_P)
404 */
405 if (eap_eke_derive_key(&data->sess, password, password_len,
406 data->serverid, data->serverid_len,
407 data->peerid, data->peerid_len, key) < 0) {
408 wpa_printf(MSG_INFO, "EAP-EKE: Failed to derive key");
409 return eap_eke_build_fail(data, ret, id,
410 EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
411 }
412
413 /*
414 * y_p = g ^ x_p (mod p)
415 * x_p = random number 2 .. p-1
416 */
417 if (eap_eke_dh_init(data->sess.dhgroup, data->dh_priv, pub) < 0) {
418 wpa_printf(MSG_INFO, "EAP-EKE: Failed to initialize DH");
419 os_memset(key, 0, sizeof(key));
420 return eap_eke_build_fail(data, ret, id,
421 EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
422 }
423
424 if (eap_eke_shared_secret(&data->sess, key, data->dh_priv, dhcomp) < 0)
425 {
426 wpa_printf(MSG_INFO, "EAP-EKE: Failed to derive shared secret");
427 os_memset(key, 0, sizeof(key));
428 return eap_eke_build_fail(data, ret, id,
429 EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
430 }
431
432 if (eap_eke_derive_ke_ki(&data->sess,
433 data->serverid, data->serverid_len,
434 data->peerid, data->peerid_len) < 0) {
435 wpa_printf(MSG_INFO, "EAP-EKE: Failed to derive Ke/Ki");
436 os_memset(key, 0, sizeof(key));
437 return eap_eke_build_fail(data, ret, id,
438 EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
439 }
440
441 wpa_printf(MSG_DEBUG, "EAP-EKE: Sending EAP-EKE-Commit/Response");
442
443 resp = eap_eke_build_msg(data, id,
444 data->sess.dhcomp_len + data->sess.pnonce_len,
445 EAP_EKE_COMMIT);
446 if (resp == NULL) {
447 os_memset(key, 0, sizeof(key));
448 return eap_eke_build_fail(data, ret, id,
449 EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
450 }
451
452 /* DHComponent_P = Encr(key, y_p) */
453 rpos = wpabuf_put(resp, data->sess.dhcomp_len);
454 if (eap_eke_dhcomp(&data->sess, key, pub, rpos) < 0) {
455 wpa_printf(MSG_INFO, "EAP-EKE: Failed to build DHComponent_P");
456 os_memset(key, 0, sizeof(key));
457 return eap_eke_build_fail(data, ret, id,
458 EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
459 }
460 os_memset(key, 0, sizeof(key));
461
462 wpa_hexdump(MSG_DEBUG, "EAP-EKE: DHComponent_P",
463 rpos, data->sess.dhcomp_len);
464
465 if (random_get_bytes(data->nonce_p, data->sess.nonce_len)) {
466 wpabuf_free(resp);
467 return eap_eke_build_fail(data, ret, id,
468 EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
469 }
470 wpa_hexdump_key(MSG_DEBUG, "EAP-EKE: Nonce_P",
471 data->nonce_p, data->sess.nonce_len);
472 prot_len = wpabuf_tailroom(resp);
473 if (eap_eke_prot(&data->sess, data->nonce_p, data->sess.nonce_len,
474 wpabuf_put(resp, 0), &prot_len) < 0) {
475 wpabuf_free(resp);
476 return eap_eke_build_fail(data, ret, id,
477 EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
478 }
479 wpa_hexdump(MSG_DEBUG, "EAP-EKE: PNonce_P",
480 wpabuf_put(resp, 0), prot_len);
481 wpabuf_put(resp, prot_len);
482
483 /* TODO: CBValue */
484
485 if (wpabuf_resize(&data->msgs, wpabuf_len(reqData) + wpabuf_len(resp))
486 < 0) {
487 wpabuf_free(resp);
488 return eap_eke_build_fail(data, ret, id,
489 EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
490 }
491 wpabuf_put_buf(data->msgs, reqData);
492 wpabuf_put_buf(data->msgs, resp);
493
494 eap_eke_state(data, CONFIRM);
495
496 return resp;
497 }
498
499
eap_eke_process_confirm(struct eap_eke_data * data,struct eap_method_ret * ret,const struct wpabuf * reqData,const u8 * payload,size_t payload_len)500 static struct wpabuf * eap_eke_process_confirm(struct eap_eke_data *data,
501 struct eap_method_ret *ret,
502 const struct wpabuf *reqData,
503 const u8 *payload,
504 size_t payload_len)
505 {
506 struct wpabuf *resp;
507 const u8 *pos, *end;
508 size_t prot_len;
509 u8 nonces[2 * EAP_EKE_MAX_NONCE_LEN];
510 u8 auth_s[EAP_EKE_MAX_HASH_LEN];
511 size_t decrypt_len;
512 u8 *auth;
513 u8 id = eap_get_id(reqData);
514
515 if (data->state != CONFIRM) {
516 wpa_printf(MSG_DEBUG, "EAP-EKE: EAP-EKE-Confirm/Request received in unexpected state (%d)",
517 data->state);
518 return eap_eke_build_fail(data, ret, id,
519 EAP_EKE_FAIL_PROTO_ERROR);
520 }
521
522 wpa_printf(MSG_DEBUG, "EAP-EKE: Received EAP-EKE-Confirm/Request");
523
524 pos = payload;
525 end = payload + payload_len;
526
527 if (pos + data->sess.pnonce_ps_len + data->sess.prf_len > end) {
528 wpa_printf(MSG_DEBUG, "EAP-EKE: Too short EAP-EKE-Confirm");
529 return eap_eke_build_fail(data, ret, id,
530 EAP_EKE_FAIL_PROTO_ERROR);
531 }
532
533 decrypt_len = sizeof(nonces);
534 if (eap_eke_decrypt_prot(&data->sess, pos, data->sess.pnonce_ps_len,
535 nonces, &decrypt_len) < 0) {
536 wpa_printf(MSG_INFO, "EAP-EKE: Failed to decrypt PNonce_PS");
537 return eap_eke_build_fail(data, ret, id,
538 EAP_EKE_FAIL_AUTHENTICATION_FAIL);
539 }
540 if (decrypt_len != (size_t) 2 * data->sess.nonce_len) {
541 wpa_printf(MSG_INFO, "EAP-EKE: PNonce_PS protected data length does not match length of Nonce_P and Nonce_S");
542 return eap_eke_build_fail(data, ret, id,
543 EAP_EKE_FAIL_AUTHENTICATION_FAIL);
544 }
545 wpa_hexdump_key(MSG_DEBUG, "EAP-EKE: Received Nonce_P | Nonce_S",
546 nonces, 2 * data->sess.nonce_len);
547 if (os_memcmp(data->nonce_p, nonces, data->sess.nonce_len) != 0) {
548 wpa_printf(MSG_INFO, "EAP-EKE: Received Nonce_P does not match transmitted Nonce_P");
549 return eap_eke_build_fail(data, ret, id,
550 EAP_EKE_FAIL_AUTHENTICATION_FAIL);
551 }
552
553 os_memcpy(data->nonce_s, nonces + data->sess.nonce_len,
554 data->sess.nonce_len);
555 wpa_hexdump_key(MSG_DEBUG, "EAP-EKE: Nonce_S",
556 data->nonce_s, data->sess.nonce_len);
557
558 if (eap_eke_derive_ka(&data->sess, data->serverid, data->serverid_len,
559 data->peerid, data->peerid_len,
560 data->nonce_p, data->nonce_s) < 0) {
561 return eap_eke_build_fail(data, ret, id,
562 EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
563 }
564
565 if (eap_eke_auth(&data->sess, "EAP-EKE server", data->msgs, auth_s) < 0)
566 {
567 return eap_eke_build_fail(data, ret, id,
568 EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
569 }
570 wpa_hexdump(MSG_DEBUG, "EAP-EKE: Auth_S", auth_s, data->sess.prf_len);
571 if (os_memcmp_const(auth_s, pos + data->sess.pnonce_ps_len,
572 data->sess.prf_len) != 0) {
573 wpa_printf(MSG_INFO, "EAP-EKE: Auth_S does not match");
574 return eap_eke_build_fail(data, ret, id,
575 EAP_EKE_FAIL_AUTHENTICATION_FAIL);
576 }
577
578 wpa_printf(MSG_DEBUG, "EAP-EKE: Sending EAP-EKE-Confirm/Response");
579
580 resp = eap_eke_build_msg(data, id,
581 data->sess.pnonce_len + data->sess.prf_len,
582 EAP_EKE_CONFIRM);
583 if (resp == NULL) {
584 return eap_eke_build_fail(data, ret, id,
585 EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
586 }
587
588 prot_len = wpabuf_tailroom(resp);
589 if (eap_eke_prot(&data->sess, data->nonce_s, data->sess.nonce_len,
590 wpabuf_put(resp, 0), &prot_len) < 0) {
591 wpabuf_free(resp);
592 return eap_eke_build_fail(data, ret, id,
593 EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
594 }
595 wpabuf_put(resp, prot_len);
596
597 auth = wpabuf_put(resp, data->sess.prf_len);
598 if (eap_eke_auth(&data->sess, "EAP-EKE peer", data->msgs, auth) < 0) {
599 wpabuf_free(resp);
600 return eap_eke_build_fail(data, ret, id,
601 EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
602 }
603 wpa_hexdump(MSG_DEBUG, "EAP-EKE: Auth_P", auth, data->sess.prf_len);
604
605 if (eap_eke_derive_msk(&data->sess, data->serverid, data->serverid_len,
606 data->peerid, data->peerid_len,
607 data->nonce_s, data->nonce_p,
608 data->msk, data->emsk) < 0) {
609 wpa_printf(MSG_INFO, "EAP-EKE: Failed to derive MSK/EMSK");
610 wpabuf_free(resp);
611 return eap_eke_build_fail(data, ret, id,
612 EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
613 }
614
615 os_memset(data->dh_priv, 0, sizeof(data->dh_priv));
616 eap_eke_session_clean(&data->sess);
617
618 eap_eke_state(data, SUCCESS);
619 ret->methodState = METHOD_MAY_CONT;
620 ret->decision = DECISION_COND_SUCC;
621 ret->allowNotifications = FALSE;
622
623 return resp;
624 }
625
626
eap_eke_process_failure(struct eap_eke_data * data,struct eap_method_ret * ret,const struct wpabuf * reqData,const u8 * payload,size_t payload_len)627 static struct wpabuf * eap_eke_process_failure(struct eap_eke_data *data,
628 struct eap_method_ret *ret,
629 const struct wpabuf *reqData,
630 const u8 *payload,
631 size_t payload_len)
632 {
633 wpa_printf(MSG_DEBUG, "EAP-EKE: Received EAP-EKE-Failure/Request");
634
635 if (payload_len < 4) {
636 wpa_printf(MSG_DEBUG, "EAP-EKE: Too short EAP-EKE-Failure");
637 } else {
638 u32 code;
639 code = WPA_GET_BE32(payload);
640 wpa_printf(MSG_INFO, "EAP-EKE: Failure-Code 0x%x", code);
641 }
642
643 return eap_eke_build_fail(data, ret, eap_get_id(reqData),
644 EAP_EKE_FAIL_NO_ERROR);
645 }
646
647
eap_eke_process(struct eap_sm * sm,void * priv,struct eap_method_ret * ret,const struct wpabuf * reqData)648 static struct wpabuf * eap_eke_process(struct eap_sm *sm, void *priv,
649 struct eap_method_ret *ret,
650 const struct wpabuf *reqData)
651 {
652 struct eap_eke_data *data = priv;
653 struct wpabuf *resp;
654 const u8 *pos, *end;
655 size_t len;
656 u8 eke_exch;
657
658 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_EKE, reqData, &len);
659 if (pos == NULL || len < 1) {
660 ret->ignore = TRUE;
661 return NULL;
662 }
663
664 end = pos + len;
665 eke_exch = *pos++;
666
667 wpa_printf(MSG_DEBUG, "EAP-EKE: Received frame: exch %d", eke_exch);
668 wpa_hexdump(MSG_DEBUG, "EAP-EKE: Received Data", pos, end - pos);
669
670 ret->ignore = FALSE;
671 ret->methodState = METHOD_MAY_CONT;
672 ret->decision = DECISION_FAIL;
673 ret->allowNotifications = TRUE;
674
675 switch (eke_exch) {
676 case EAP_EKE_ID:
677 resp = eap_eke_process_id(data, ret, reqData, pos, end - pos);
678 break;
679 case EAP_EKE_COMMIT:
680 resp = eap_eke_process_commit(sm, data, ret, reqData,
681 pos, end - pos);
682 break;
683 case EAP_EKE_CONFIRM:
684 resp = eap_eke_process_confirm(data, ret, reqData,
685 pos, end - pos);
686 break;
687 case EAP_EKE_FAILURE:
688 resp = eap_eke_process_failure(data, ret, reqData,
689 pos, end - pos);
690 break;
691 default:
692 wpa_printf(MSG_DEBUG, "EAP-EKE: Ignoring message with unknown EKE-Exch %d", eke_exch);
693 ret->ignore = TRUE;
694 return NULL;
695 }
696
697 if (ret->methodState == METHOD_DONE)
698 ret->allowNotifications = FALSE;
699
700 return resp;
701 }
702
703
eap_eke_isKeyAvailable(struct eap_sm * sm,void * priv)704 static Boolean eap_eke_isKeyAvailable(struct eap_sm *sm, void *priv)
705 {
706 struct eap_eke_data *data = priv;
707 return data->state == SUCCESS;
708 }
709
710
eap_eke_getKey(struct eap_sm * sm,void * priv,size_t * len)711 static u8 * eap_eke_getKey(struct eap_sm *sm, void *priv, size_t *len)
712 {
713 struct eap_eke_data *data = priv;
714 u8 *key;
715
716 if (data->state != SUCCESS)
717 return NULL;
718
719 key = os_malloc(EAP_MSK_LEN);
720 if (key == NULL)
721 return NULL;
722 os_memcpy(key, data->msk, EAP_MSK_LEN);
723 *len = EAP_MSK_LEN;
724
725 return key;
726 }
727
728
eap_eke_get_emsk(struct eap_sm * sm,void * priv,size_t * len)729 static u8 * eap_eke_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
730 {
731 struct eap_eke_data *data = priv;
732 u8 *key;
733
734 if (data->state != SUCCESS)
735 return NULL;
736
737 key = os_malloc(EAP_EMSK_LEN);
738 if (key == NULL)
739 return NULL;
740 os_memcpy(key, data->emsk, EAP_EMSK_LEN);
741 *len = EAP_EMSK_LEN;
742
743 return key;
744 }
745
746
eap_eke_get_session_id(struct eap_sm * sm,void * priv,size_t * len)747 static u8 * eap_eke_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
748 {
749 struct eap_eke_data *data = priv;
750 u8 *sid;
751 size_t sid_len;
752
753 if (data->state != SUCCESS)
754 return NULL;
755
756 sid_len = 1 + 2 * data->sess.nonce_len;
757 sid = os_malloc(sid_len);
758 if (sid == NULL)
759 return NULL;
760 sid[0] = EAP_TYPE_EKE;
761 os_memcpy(sid + 1, data->nonce_p, data->sess.nonce_len);
762 os_memcpy(sid + 1 + data->sess.nonce_len, data->nonce_s,
763 data->sess.nonce_len);
764 *len = sid_len;
765
766 return sid;
767 }
768
769
eap_peer_eke_register(void)770 int eap_peer_eke_register(void)
771 {
772 struct eap_method *eap;
773 int ret;
774
775 eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
776 EAP_VENDOR_IETF, EAP_TYPE_EKE, "EKE");
777 if (eap == NULL)
778 return -1;
779
780 eap->init = eap_eke_init;
781 eap->deinit = eap_eke_deinit;
782 eap->process = eap_eke_process;
783 eap->isKeyAvailable = eap_eke_isKeyAvailable;
784 eap->getKey = eap_eke_getKey;
785 eap->get_emsk = eap_eke_get_emsk;
786 eap->getSessionId = eap_eke_get_session_id;
787
788 ret = eap_peer_method_register(eap);
789 if (ret)
790 eap_peer_method_free(eap);
791 return ret;
792 }
793