1 /*
2 * hostapd / EAP-SIM (RFC 4186)
3 * Copyright (c) 2005-2012, 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_server/eap_i.h"
14 #include "eap_common/eap_sim_common.h"
15 #include "eap_server/eap_sim_db.h"
16
17
18 struct eap_sim_data {
19 u8 mk[EAP_SIM_MK_LEN];
20 u8 nonce_mt[EAP_SIM_NONCE_MT_LEN];
21 u8 nonce_s[EAP_SIM_NONCE_S_LEN];
22 u8 k_aut[EAP_SIM_K_AUT_LEN];
23 u8 k_encr[EAP_SIM_K_ENCR_LEN];
24 u8 msk[EAP_SIM_KEYING_DATA_LEN];
25 u8 emsk[EAP_EMSK_LEN];
26 u8 kc[EAP_SIM_MAX_CHAL][EAP_SIM_KC_LEN];
27 u8 sres[EAP_SIM_MAX_CHAL][EAP_SIM_SRES_LEN];
28 u8 rand[EAP_SIM_MAX_CHAL][GSM_RAND_LEN];
29 u8 reauth_mac[EAP_SIM_MAC_LEN];
30 int num_chal;
31 enum {
32 START, CHALLENGE, REAUTH, NOTIFICATION, SUCCESS, FAILURE
33 } state;
34 char *next_pseudonym;
35 char *next_reauth_id;
36 u16 counter;
37 struct eap_sim_reauth *reauth;
38 u16 notification;
39 int use_result_ind;
40 int start_round;
41 char permanent[20]; /* Permanent username */
42 };
43
44
eap_sim_state_txt(int state)45 static const char * eap_sim_state_txt(int state)
46 {
47 switch (state) {
48 case START:
49 return "START";
50 case CHALLENGE:
51 return "CHALLENGE";
52 case REAUTH:
53 return "REAUTH";
54 case SUCCESS:
55 return "SUCCESS";
56 case FAILURE:
57 return "FAILURE";
58 case NOTIFICATION:
59 return "NOTIFICATION";
60 default:
61 return "Unknown?!";
62 }
63 }
64
65
eap_sim_state(struct eap_sim_data * data,int state)66 static void eap_sim_state(struct eap_sim_data *data, int state)
67 {
68 wpa_printf(MSG_DEBUG, "EAP-SIM: %s -> %s",
69 eap_sim_state_txt(data->state),
70 eap_sim_state_txt(state));
71 data->state = state;
72 }
73
74
eap_sim_init(struct eap_sm * sm)75 static void * eap_sim_init(struct eap_sm *sm)
76 {
77 struct eap_sim_data *data;
78
79 if (sm->eap_sim_db_priv == NULL) {
80 wpa_printf(MSG_WARNING, "EAP-SIM: eap_sim_db not configured");
81 return NULL;
82 }
83
84 data = os_zalloc(sizeof(*data));
85 if (data == NULL)
86 return NULL;
87 data->state = START;
88
89 return data;
90 }
91
92
eap_sim_reset(struct eap_sm * sm,void * priv)93 static void eap_sim_reset(struct eap_sm *sm, void *priv)
94 {
95 struct eap_sim_data *data = priv;
96 os_free(data->next_pseudonym);
97 os_free(data->next_reauth_id);
98 bin_clear_free(data, sizeof(*data));
99 }
100
101
eap_sim_build_start(struct eap_sm * sm,struct eap_sim_data * data,u8 id)102 static struct wpabuf * eap_sim_build_start(struct eap_sm *sm,
103 struct eap_sim_data *data, u8 id)
104 {
105 struct eap_sim_msg *msg;
106 u8 ver[2];
107
108 wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Start");
109 msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM,
110 EAP_SIM_SUBTYPE_START);
111 data->start_round++;
112 if (data->start_round == 1) {
113 /*
114 * RFC 4186, Chap. 4.2.4 recommends that identity from EAP is
115 * ignored and the SIM/Start is used to request the identity.
116 */
117 wpa_printf(MSG_DEBUG, " AT_ANY_ID_REQ");
118 eap_sim_msg_add(msg, EAP_SIM_AT_ANY_ID_REQ, 0, NULL, 0);
119 } else if (data->start_round > 3) {
120 /* Cannot use more than three rounds of Start messages */
121 eap_sim_msg_free(msg);
122 return NULL;
123 } else if (data->start_round == 0) {
124 /*
125 * This is a special case that is used to recover from
126 * AT_COUNTER_TOO_SMALL during re-authentication. Since we
127 * already know the identity of the peer, there is no need to
128 * request any identity in this case.
129 */
130 } else if (sm->identity && sm->identity_len > 0 &&
131 sm->identity[0] == EAP_SIM_REAUTH_ID_PREFIX) {
132 /* Reauth id may have expired - try fullauth */
133 wpa_printf(MSG_DEBUG, " AT_FULLAUTH_ID_REQ");
134 eap_sim_msg_add(msg, EAP_SIM_AT_FULLAUTH_ID_REQ, 0, NULL, 0);
135 } else {
136 wpa_printf(MSG_DEBUG, " AT_PERMANENT_ID_REQ");
137 eap_sim_msg_add(msg, EAP_SIM_AT_PERMANENT_ID_REQ, 0, NULL, 0);
138 }
139 wpa_printf(MSG_DEBUG, " AT_VERSION_LIST");
140 ver[0] = 0;
141 ver[1] = EAP_SIM_VERSION;
142 eap_sim_msg_add(msg, EAP_SIM_AT_VERSION_LIST, sizeof(ver),
143 ver, sizeof(ver));
144 return eap_sim_msg_finish(msg, EAP_TYPE_SIM, NULL, NULL, 0);
145 }
146
147
eap_sim_build_encr(struct eap_sm * sm,struct eap_sim_data * data,struct eap_sim_msg * msg,u16 counter,const u8 * nonce_s)148 static int eap_sim_build_encr(struct eap_sm *sm, struct eap_sim_data *data,
149 struct eap_sim_msg *msg, u16 counter,
150 const u8 *nonce_s)
151 {
152 os_free(data->next_pseudonym);
153 if (!(sm->eap_sim_id & 0x01)) {
154 /* Use of pseudonyms disabled in configuration */
155 data->next_pseudonym = NULL;
156 } else if (!nonce_s) {
157 data->next_pseudonym =
158 eap_sim_db_get_next_pseudonym(sm->eap_sim_db_priv,
159 EAP_SIM_DB_SIM);
160 } else {
161 /* Do not update pseudonym during re-authentication */
162 data->next_pseudonym = NULL;
163 }
164 os_free(data->next_reauth_id);
165 if (!(sm->eap_sim_id & 0x02)) {
166 /* Use of fast reauth disabled in configuration */
167 data->next_reauth_id = NULL;
168 } else if (data->counter <= EAP_SIM_MAX_FAST_REAUTHS) {
169 data->next_reauth_id =
170 eap_sim_db_get_next_reauth_id(sm->eap_sim_db_priv,
171 EAP_SIM_DB_SIM);
172 } else {
173 wpa_printf(MSG_DEBUG, "EAP-SIM: Max fast re-authentication "
174 "count exceeded - force full authentication");
175 data->next_reauth_id = NULL;
176 }
177
178 if (data->next_pseudonym == NULL && data->next_reauth_id == NULL &&
179 counter == 0 && nonce_s == NULL)
180 return 0;
181
182 wpa_printf(MSG_DEBUG, " AT_IV");
183 wpa_printf(MSG_DEBUG, " AT_ENCR_DATA");
184 eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV, EAP_SIM_AT_ENCR_DATA);
185
186 if (counter > 0) {
187 wpa_printf(MSG_DEBUG, " *AT_COUNTER (%u)", counter);
188 eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, counter, NULL, 0);
189 }
190
191 if (nonce_s) {
192 wpa_printf(MSG_DEBUG, " *AT_NONCE_S");
193 eap_sim_msg_add(msg, EAP_SIM_AT_NONCE_S, 0, nonce_s,
194 EAP_SIM_NONCE_S_LEN);
195 }
196
197 if (data->next_pseudonym) {
198 wpa_printf(MSG_DEBUG, " *AT_NEXT_PSEUDONYM (%s)",
199 data->next_pseudonym);
200 eap_sim_msg_add(msg, EAP_SIM_AT_NEXT_PSEUDONYM,
201 os_strlen(data->next_pseudonym),
202 (u8 *) data->next_pseudonym,
203 os_strlen(data->next_pseudonym));
204 }
205
206 if (data->next_reauth_id) {
207 wpa_printf(MSG_DEBUG, " *AT_NEXT_REAUTH_ID (%s)",
208 data->next_reauth_id);
209 eap_sim_msg_add(msg, EAP_SIM_AT_NEXT_REAUTH_ID,
210 os_strlen(data->next_reauth_id),
211 (u8 *) data->next_reauth_id,
212 os_strlen(data->next_reauth_id));
213 }
214
215 if (eap_sim_msg_add_encr_end(msg, data->k_encr, EAP_SIM_AT_PADDING)) {
216 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to encrypt "
217 "AT_ENCR_DATA");
218 return -1;
219 }
220
221 return 0;
222 }
223
224
eap_sim_build_challenge(struct eap_sm * sm,struct eap_sim_data * data,u8 id)225 static struct wpabuf * eap_sim_build_challenge(struct eap_sm *sm,
226 struct eap_sim_data *data,
227 u8 id)
228 {
229 struct eap_sim_msg *msg;
230
231 wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Challenge");
232 msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM,
233 EAP_SIM_SUBTYPE_CHALLENGE);
234 wpa_printf(MSG_DEBUG, " AT_RAND");
235 eap_sim_msg_add(msg, EAP_SIM_AT_RAND, 0, (u8 *) data->rand,
236 data->num_chal * GSM_RAND_LEN);
237
238 if (eap_sim_build_encr(sm, data, msg, 0, NULL)) {
239 eap_sim_msg_free(msg);
240 return NULL;
241 }
242
243 if (sm->eap_sim_aka_result_ind) {
244 wpa_printf(MSG_DEBUG, " AT_RESULT_IND");
245 eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0);
246 }
247
248 wpa_printf(MSG_DEBUG, " AT_MAC");
249 eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
250 return eap_sim_msg_finish(msg, EAP_TYPE_SIM, data->k_aut,
251 data->nonce_mt, EAP_SIM_NONCE_MT_LEN);
252 }
253
254
eap_sim_build_reauth(struct eap_sm * sm,struct eap_sim_data * data,u8 id)255 static struct wpabuf * eap_sim_build_reauth(struct eap_sm *sm,
256 struct eap_sim_data *data, u8 id)
257 {
258 struct eap_sim_msg *msg;
259 struct wpabuf *buf;
260
261 wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Re-authentication");
262
263 if (random_get_bytes(data->nonce_s, EAP_SIM_NONCE_S_LEN))
264 return NULL;
265 wpa_hexdump_key(MSG_MSGDUMP, "EAP-SIM: NONCE_S",
266 data->nonce_s, EAP_SIM_NONCE_S_LEN);
267
268 eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut, data->msk,
269 data->emsk);
270 eap_sim_derive_keys_reauth(data->counter, sm->identity,
271 sm->identity_len, data->nonce_s, data->mk,
272 data->msk, data->emsk);
273
274 msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM,
275 EAP_SIM_SUBTYPE_REAUTHENTICATION);
276
277 if (eap_sim_build_encr(sm, data, msg, data->counter, data->nonce_s)) {
278 eap_sim_msg_free(msg);
279 return NULL;
280 }
281
282 if (sm->eap_sim_aka_result_ind) {
283 wpa_printf(MSG_DEBUG, " AT_RESULT_IND");
284 eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0);
285 }
286
287 wpa_printf(MSG_DEBUG, " AT_MAC");
288 eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
289 buf = eap_sim_msg_finish(msg, EAP_TYPE_SIM, data->k_aut, NULL, 0);
290
291 /* Remember this MAC before sending it to the peer. This MAC is used for
292 * Session-Id calculation after receiving response from the peer and
293 * after all other checks pass. */
294 os_memcpy(data->reauth_mac,
295 wpabuf_head_u8(buf) + wpabuf_len(buf) - EAP_SIM_MAC_LEN,
296 EAP_SIM_MAC_LEN);
297
298 return buf;
299 }
300
301
eap_sim_build_notification(struct eap_sm * sm,struct eap_sim_data * data,u8 id)302 static struct wpabuf * eap_sim_build_notification(struct eap_sm *sm,
303 struct eap_sim_data *data,
304 u8 id)
305 {
306 struct eap_sim_msg *msg;
307
308 wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Notification");
309 msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM,
310 EAP_SIM_SUBTYPE_NOTIFICATION);
311 wpa_printf(MSG_DEBUG, " AT_NOTIFICATION (%d)", data->notification);
312 eap_sim_msg_add(msg, EAP_SIM_AT_NOTIFICATION, data->notification,
313 NULL, 0);
314 if (data->use_result_ind) {
315 if (data->reauth) {
316 wpa_printf(MSG_DEBUG, " AT_IV");
317 wpa_printf(MSG_DEBUG, " AT_ENCR_DATA");
318 eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV,
319 EAP_SIM_AT_ENCR_DATA);
320 wpa_printf(MSG_DEBUG, " *AT_COUNTER (%u)",
321 data->counter);
322 eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, data->counter,
323 NULL, 0);
324
325 if (eap_sim_msg_add_encr_end(msg, data->k_encr,
326 EAP_SIM_AT_PADDING)) {
327 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to "
328 "encrypt AT_ENCR_DATA");
329 eap_sim_msg_free(msg);
330 return NULL;
331 }
332 }
333
334 wpa_printf(MSG_DEBUG, " AT_MAC");
335 eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
336 }
337 return eap_sim_msg_finish(msg, EAP_TYPE_SIM, data->k_aut, NULL, 0);
338 }
339
340
eap_sim_buildReq(struct eap_sm * sm,void * priv,u8 id)341 static struct wpabuf * eap_sim_buildReq(struct eap_sm *sm, void *priv, u8 id)
342 {
343 struct eap_sim_data *data = priv;
344
345 switch (data->state) {
346 case START:
347 return eap_sim_build_start(sm, data, id);
348 case CHALLENGE:
349 return eap_sim_build_challenge(sm, data, id);
350 case REAUTH:
351 return eap_sim_build_reauth(sm, data, id);
352 case NOTIFICATION:
353 return eap_sim_build_notification(sm, data, id);
354 default:
355 wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown state %d in "
356 "buildReq", data->state);
357 break;
358 }
359 return NULL;
360 }
361
362
eap_sim_check(struct eap_sm * sm,void * priv,struct wpabuf * respData)363 static Boolean eap_sim_check(struct eap_sm *sm, void *priv,
364 struct wpabuf *respData)
365 {
366 const u8 *pos;
367 size_t len;
368
369 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SIM, respData, &len);
370 if (pos == NULL || len < 3) {
371 wpa_printf(MSG_INFO, "EAP-SIM: Invalid frame");
372 return TRUE;
373 }
374
375 return FALSE;
376 }
377
378
eap_sim_unexpected_subtype(struct eap_sim_data * data,u8 subtype)379 static Boolean eap_sim_unexpected_subtype(struct eap_sim_data *data,
380 u8 subtype)
381 {
382 if (subtype == EAP_SIM_SUBTYPE_CLIENT_ERROR)
383 return FALSE;
384
385 switch (data->state) {
386 case START:
387 if (subtype != EAP_SIM_SUBTYPE_START) {
388 wpa_printf(MSG_INFO, "EAP-SIM: Unexpected response "
389 "subtype %d", subtype);
390 return TRUE;
391 }
392 break;
393 case CHALLENGE:
394 if (subtype != EAP_SIM_SUBTYPE_CHALLENGE) {
395 wpa_printf(MSG_INFO, "EAP-SIM: Unexpected response "
396 "subtype %d", subtype);
397 return TRUE;
398 }
399 break;
400 case REAUTH:
401 if (subtype != EAP_SIM_SUBTYPE_REAUTHENTICATION) {
402 wpa_printf(MSG_INFO, "EAP-SIM: Unexpected response "
403 "subtype %d", subtype);
404 return TRUE;
405 }
406 break;
407 case NOTIFICATION:
408 if (subtype != EAP_SIM_SUBTYPE_NOTIFICATION) {
409 wpa_printf(MSG_INFO, "EAP-SIM: Unexpected response "
410 "subtype %d", subtype);
411 return TRUE;
412 }
413 break;
414 default:
415 wpa_printf(MSG_INFO, "EAP-SIM: Unexpected state (%d) for "
416 "processing a response", data->state);
417 return TRUE;
418 }
419
420 return FALSE;
421 }
422
423
eap_sim_supported_ver(struct eap_sim_data * data,int version)424 static int eap_sim_supported_ver(struct eap_sim_data *data, int version)
425 {
426 return version == EAP_SIM_VERSION;
427 }
428
429
eap_sim_process_start(struct eap_sm * sm,struct eap_sim_data * data,struct wpabuf * respData,struct eap_sim_attrs * attr)430 static void eap_sim_process_start(struct eap_sm *sm,
431 struct eap_sim_data *data,
432 struct wpabuf *respData,
433 struct eap_sim_attrs *attr)
434 {
435 size_t identity_len;
436 u8 ver_list[2];
437 u8 *new_identity;
438 char *username;
439
440 wpa_printf(MSG_DEBUG, "EAP-SIM: Receive start response");
441
442 if (data->start_round == 0) {
443 /*
444 * Special case for AT_COUNTER_TOO_SMALL recovery - no identity
445 * was requested since we already know it.
446 */
447 goto skip_id_update;
448 }
449
450 /*
451 * We always request identity in SIM/Start, so the peer is required to
452 * have replied with one.
453 */
454 if (!attr->identity || attr->identity_len == 0) {
455 wpa_printf(MSG_DEBUG, "EAP-SIM: Peer did not provide any "
456 "identity");
457 goto failed;
458 }
459
460 new_identity = os_malloc(attr->identity_len);
461 if (new_identity == NULL)
462 goto failed;
463 os_free(sm->identity);
464 sm->identity = new_identity;
465 os_memcpy(sm->identity, attr->identity, attr->identity_len);
466 sm->identity_len = attr->identity_len;
467
468 wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Identity",
469 sm->identity, sm->identity_len);
470 username = sim_get_username(sm->identity, sm->identity_len);
471 if (username == NULL)
472 goto failed;
473
474 if (username[0] == EAP_SIM_REAUTH_ID_PREFIX) {
475 wpa_printf(MSG_DEBUG, "EAP-SIM: Reauth username '%s'",
476 username);
477 data->reauth = eap_sim_db_get_reauth_entry(
478 sm->eap_sim_db_priv, username);
479 os_free(username);
480 if (data->reauth == NULL) {
481 wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown reauth "
482 "identity - request full auth identity");
483 /* Remain in START state for another round */
484 return;
485 }
486 wpa_printf(MSG_DEBUG, "EAP-SIM: Using fast re-authentication");
487 os_strlcpy(data->permanent, data->reauth->permanent,
488 sizeof(data->permanent));
489 data->counter = data->reauth->counter;
490 os_memcpy(data->mk, data->reauth->mk, EAP_SIM_MK_LEN);
491 eap_sim_state(data, REAUTH);
492 return;
493 }
494
495 if (username[0] == EAP_SIM_PSEUDONYM_PREFIX) {
496 const char *permanent;
497 wpa_printf(MSG_DEBUG, "EAP-SIM: Pseudonym username '%s'",
498 username);
499 permanent = eap_sim_db_get_permanent(
500 sm->eap_sim_db_priv, username);
501 os_free(username);
502 if (permanent == NULL) {
503 wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown pseudonym "
504 "identity - request permanent identity");
505 /* Remain in START state for another round */
506 return;
507 }
508 os_strlcpy(data->permanent, permanent,
509 sizeof(data->permanent));
510 } else if (username[0] == EAP_SIM_PERMANENT_PREFIX) {
511 wpa_printf(MSG_DEBUG, "EAP-SIM: Permanent username '%s'",
512 username);
513 os_strlcpy(data->permanent, username, sizeof(data->permanent));
514 os_free(username);
515 } else {
516 wpa_printf(MSG_DEBUG, "EAP-SIM: Unrecognized username '%s'",
517 username);
518 os_free(username);
519 goto failed;
520 }
521
522 skip_id_update:
523 /* Full authentication */
524
525 if (attr->nonce_mt == NULL || attr->selected_version < 0) {
526 wpa_printf(MSG_DEBUG, "EAP-SIM: Start/Response missing "
527 "required attributes");
528 goto failed;
529 }
530
531 if (!eap_sim_supported_ver(data, attr->selected_version)) {
532 wpa_printf(MSG_DEBUG, "EAP-SIM: Peer selected unsupported "
533 "version %d", attr->selected_version);
534 goto failed;
535 }
536
537 data->counter = 0; /* reset re-auth counter since this is full auth */
538 data->reauth = NULL;
539
540 data->num_chal = eap_sim_db_get_gsm_triplets(
541 sm->eap_sim_db_priv, data->permanent, EAP_SIM_MAX_CHAL,
542 (u8 *) data->rand, (u8 *) data->kc, (u8 *) data->sres, sm);
543 if (data->num_chal == EAP_SIM_DB_PENDING) {
544 wpa_printf(MSG_DEBUG, "EAP-SIM: GSM authentication triplets "
545 "not yet available - pending request");
546 sm->method_pending = METHOD_PENDING_WAIT;
547 return;
548 }
549 if (data->num_chal < 2) {
550 wpa_printf(MSG_INFO, "EAP-SIM: Failed to get GSM "
551 "authentication triplets for the peer");
552 goto failed;
553 }
554
555 if (data->permanent[0] == EAP_SIM_PERMANENT_PREFIX)
556 os_strlcpy(sm->imsi, &data->permanent[1], sizeof(sm->imsi));
557
558 identity_len = sm->identity_len;
559 while (identity_len > 0 && sm->identity[identity_len - 1] == '\0') {
560 wpa_printf(MSG_DEBUG, "EAP-SIM: Workaround - drop last null "
561 "character from identity");
562 identity_len--;
563 }
564 wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Identity for MK derivation",
565 sm->identity, identity_len);
566
567 os_memcpy(data->nonce_mt, attr->nonce_mt, EAP_SIM_NONCE_MT_LEN);
568 WPA_PUT_BE16(ver_list, EAP_SIM_VERSION);
569 eap_sim_derive_mk(sm->identity, identity_len, attr->nonce_mt,
570 attr->selected_version, ver_list, sizeof(ver_list),
571 data->num_chal, (const u8 *) data->kc, data->mk);
572 eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut, data->msk,
573 data->emsk);
574
575 eap_sim_state(data, CHALLENGE);
576 return;
577
578 failed:
579 data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
580 eap_sim_state(data, NOTIFICATION);
581 }
582
583
eap_sim_process_challenge(struct eap_sm * sm,struct eap_sim_data * data,struct wpabuf * respData,struct eap_sim_attrs * attr)584 static void eap_sim_process_challenge(struct eap_sm *sm,
585 struct eap_sim_data *data,
586 struct wpabuf *respData,
587 struct eap_sim_attrs *attr)
588 {
589 if (attr->mac == NULL ||
590 eap_sim_verify_mac(data->k_aut, respData, attr->mac,
591 (u8 *) data->sres,
592 data->num_chal * EAP_SIM_SRES_LEN)) {
593 wpa_printf(MSG_WARNING, "EAP-SIM: Challenge message "
594 "did not include valid AT_MAC");
595 data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
596 eap_sim_state(data, NOTIFICATION);
597 return;
598 }
599
600 wpa_printf(MSG_DEBUG, "EAP-SIM: Challenge response includes the "
601 "correct AT_MAC");
602 if (sm->eap_sim_aka_result_ind && attr->result_ind) {
603 data->use_result_ind = 1;
604 data->notification = EAP_SIM_SUCCESS;
605 eap_sim_state(data, NOTIFICATION);
606 } else
607 eap_sim_state(data, SUCCESS);
608
609 if (data->next_pseudonym) {
610 eap_sim_db_add_pseudonym(sm->eap_sim_db_priv, data->permanent,
611 data->next_pseudonym);
612 data->next_pseudonym = NULL;
613 }
614 if (data->next_reauth_id) {
615 eap_sim_db_add_reauth(sm->eap_sim_db_priv, data->permanent,
616 data->next_reauth_id, data->counter + 1,
617 data->mk);
618 data->next_reauth_id = NULL;
619 }
620 }
621
622
eap_sim_process_reauth(struct eap_sm * sm,struct eap_sim_data * data,struct wpabuf * respData,struct eap_sim_attrs * attr)623 static void eap_sim_process_reauth(struct eap_sm *sm,
624 struct eap_sim_data *data,
625 struct wpabuf *respData,
626 struct eap_sim_attrs *attr)
627 {
628 struct eap_sim_attrs eattr;
629 u8 *decrypted = NULL;
630
631 if (attr->mac == NULL ||
632 eap_sim_verify_mac(data->k_aut, respData, attr->mac, data->nonce_s,
633 EAP_SIM_NONCE_S_LEN)) {
634 wpa_printf(MSG_WARNING, "EAP-SIM: Re-authentication message "
635 "did not include valid AT_MAC");
636 goto fail;
637 }
638
639 if (attr->encr_data == NULL || attr->iv == NULL) {
640 wpa_printf(MSG_WARNING, "EAP-SIM: Reauthentication "
641 "message did not include encrypted data");
642 goto fail;
643 }
644
645 decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
646 attr->encr_data_len, attr->iv, &eattr,
647 0);
648 if (decrypted == NULL) {
649 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to parse encrypted "
650 "data from reauthentication message");
651 goto fail;
652 }
653
654 if (eattr.counter != data->counter) {
655 wpa_printf(MSG_WARNING, "EAP-SIM: Re-authentication message "
656 "used incorrect counter %u, expected %u",
657 eattr.counter, data->counter);
658 goto fail;
659 }
660 os_free(decrypted);
661 decrypted = NULL;
662
663 wpa_printf(MSG_DEBUG, "EAP-SIM: Re-authentication response includes "
664 "the correct AT_MAC");
665
666 if (eattr.counter_too_small) {
667 wpa_printf(MSG_DEBUG, "EAP-AKA: Re-authentication response "
668 "included AT_COUNTER_TOO_SMALL - starting full "
669 "authentication");
670 data->start_round = -1;
671 eap_sim_state(data, START);
672 return;
673 }
674
675 if (sm->eap_sim_aka_result_ind && attr->result_ind) {
676 data->use_result_ind = 1;
677 data->notification = EAP_SIM_SUCCESS;
678 eap_sim_state(data, NOTIFICATION);
679 } else
680 eap_sim_state(data, SUCCESS);
681
682 if (data->next_reauth_id) {
683 eap_sim_db_add_reauth(sm->eap_sim_db_priv, data->permanent,
684 data->next_reauth_id,
685 data->counter + 1, data->mk);
686 data->next_reauth_id = NULL;
687 } else {
688 eap_sim_db_remove_reauth(sm->eap_sim_db_priv, data->reauth);
689 data->reauth = NULL;
690 }
691
692 return;
693
694 fail:
695 data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
696 eap_sim_state(data, NOTIFICATION);
697 eap_sim_db_remove_reauth(sm->eap_sim_db_priv, data->reauth);
698 data->reauth = NULL;
699 os_free(decrypted);
700 }
701
702
eap_sim_process_client_error(struct eap_sm * sm,struct eap_sim_data * data,struct wpabuf * respData,struct eap_sim_attrs * attr)703 static void eap_sim_process_client_error(struct eap_sm *sm,
704 struct eap_sim_data *data,
705 struct wpabuf *respData,
706 struct eap_sim_attrs *attr)
707 {
708 wpa_printf(MSG_DEBUG, "EAP-SIM: Client reported error %d",
709 attr->client_error_code);
710 if (data->notification == EAP_SIM_SUCCESS && data->use_result_ind)
711 eap_sim_state(data, SUCCESS);
712 else
713 eap_sim_state(data, FAILURE);
714 }
715
716
eap_sim_process_notification(struct eap_sm * sm,struct eap_sim_data * data,struct wpabuf * respData,struct eap_sim_attrs * attr)717 static void eap_sim_process_notification(struct eap_sm *sm,
718 struct eap_sim_data *data,
719 struct wpabuf *respData,
720 struct eap_sim_attrs *attr)
721 {
722 wpa_printf(MSG_DEBUG, "EAP-SIM: Client replied to notification");
723 if (data->notification == EAP_SIM_SUCCESS && data->use_result_ind)
724 eap_sim_state(data, SUCCESS);
725 else
726 eap_sim_state(data, FAILURE);
727 }
728
729
eap_sim_process(struct eap_sm * sm,void * priv,struct wpabuf * respData)730 static void eap_sim_process(struct eap_sm *sm, void *priv,
731 struct wpabuf *respData)
732 {
733 struct eap_sim_data *data = priv;
734 const u8 *pos, *end;
735 u8 subtype;
736 size_t len;
737 struct eap_sim_attrs attr;
738
739 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SIM, respData, &len);
740 if (pos == NULL || len < 3)
741 return;
742
743 end = pos + len;
744 subtype = *pos;
745 pos += 3;
746
747 if (eap_sim_unexpected_subtype(data, subtype)) {
748 wpa_printf(MSG_DEBUG, "EAP-SIM: Unrecognized or unexpected "
749 "EAP-SIM Subtype in EAP Response");
750 data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
751 eap_sim_state(data, NOTIFICATION);
752 return;
753 }
754
755 if (eap_sim_parse_attr(pos, end, &attr, 0, 0)) {
756 wpa_printf(MSG_DEBUG, "EAP-SIM: Failed to parse attributes");
757 if (subtype != EAP_SIM_SUBTYPE_CLIENT_ERROR &&
758 (data->state == START || data->state == CHALLENGE ||
759 data->state == REAUTH)) {
760 data->notification =
761 EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
762 eap_sim_state(data, NOTIFICATION);
763 return;
764 }
765 eap_sim_state(data, FAILURE);
766 return;
767 }
768
769 if (subtype == EAP_SIM_SUBTYPE_CLIENT_ERROR) {
770 eap_sim_process_client_error(sm, data, respData, &attr);
771 return;
772 }
773
774 switch (data->state) {
775 case START:
776 eap_sim_process_start(sm, data, respData, &attr);
777 break;
778 case CHALLENGE:
779 eap_sim_process_challenge(sm, data, respData, &attr);
780 break;
781 case REAUTH:
782 eap_sim_process_reauth(sm, data, respData, &attr);
783 break;
784 case NOTIFICATION:
785 eap_sim_process_notification(sm, data, respData, &attr);
786 break;
787 default:
788 wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown state %d in "
789 "process", data->state);
790 break;
791 }
792 }
793
794
eap_sim_isDone(struct eap_sm * sm,void * priv)795 static Boolean eap_sim_isDone(struct eap_sm *sm, void *priv)
796 {
797 struct eap_sim_data *data = priv;
798 return data->state == SUCCESS || data->state == FAILURE;
799 }
800
801
eap_sim_getKey(struct eap_sm * sm,void * priv,size_t * len)802 static u8 * eap_sim_getKey(struct eap_sm *sm, void *priv, size_t *len)
803 {
804 struct eap_sim_data *data = priv;
805 u8 *key;
806
807 if (data->state != SUCCESS)
808 return NULL;
809
810 key = os_memdup(data->msk, EAP_SIM_KEYING_DATA_LEN);
811 if (key == NULL)
812 return NULL;
813 *len = EAP_SIM_KEYING_DATA_LEN;
814 return key;
815 }
816
817
eap_sim_get_emsk(struct eap_sm * sm,void * priv,size_t * len)818 static u8 * eap_sim_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
819 {
820 struct eap_sim_data *data = priv;
821 u8 *key;
822
823 if (data->state != SUCCESS)
824 return NULL;
825
826 key = os_memdup(data->emsk, EAP_EMSK_LEN);
827 if (key == NULL)
828 return NULL;
829 *len = EAP_EMSK_LEN;
830 return key;
831 }
832
833
eap_sim_isSuccess(struct eap_sm * sm,void * priv)834 static Boolean eap_sim_isSuccess(struct eap_sm *sm, void *priv)
835 {
836 struct eap_sim_data *data = priv;
837 return data->state == SUCCESS;
838 }
839
840
eap_sim_get_session_id(struct eap_sm * sm,void * priv,size_t * len)841 static u8 * eap_sim_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
842 {
843 struct eap_sim_data *data = priv;
844 u8 *id;
845
846 if (data->state != SUCCESS)
847 return NULL;
848
849 if (!data->reauth)
850 *len = 1 + data->num_chal * GSM_RAND_LEN + EAP_SIM_NONCE_MT_LEN;
851 else
852 *len = 1 + EAP_SIM_NONCE_S_LEN + EAP_SIM_MAC_LEN;
853 id = os_malloc(*len);
854 if (id == NULL)
855 return NULL;
856
857 id[0] = EAP_TYPE_SIM;
858 if (!data->reauth) {
859 os_memcpy(id + 1, data->rand, data->num_chal * GSM_RAND_LEN);
860 os_memcpy(id + 1 + data->num_chal * GSM_RAND_LEN,
861 data->nonce_mt, EAP_SIM_NONCE_MT_LEN);
862 } else {
863 os_memcpy(id + 1, data->nonce_s, EAP_SIM_NONCE_S_LEN);
864 os_memcpy(id + 1 + EAP_SIM_NONCE_S_LEN, data->reauth_mac,
865 EAP_SIM_MAC_LEN);
866
867 }
868 wpa_hexdump(MSG_DEBUG, "EAP-SIM: Derived Session-Id", id, *len);
869
870 return id;
871 }
872
873
eap_server_sim_register(void)874 int eap_server_sim_register(void)
875 {
876 struct eap_method *eap;
877
878 eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
879 EAP_VENDOR_IETF, EAP_TYPE_SIM, "SIM");
880 if (eap == NULL)
881 return -1;
882
883 eap->init = eap_sim_init;
884 eap->reset = eap_sim_reset;
885 eap->buildReq = eap_sim_buildReq;
886 eap->check = eap_sim_check;
887 eap->process = eap_sim_process;
888 eap->isDone = eap_sim_isDone;
889 eap->getKey = eap_sim_getKey;
890 eap->isSuccess = eap_sim_isSuccess;
891 eap->get_emsk = eap_sim_get_emsk;
892 eap->getSessionId = eap_sim_get_session_id;
893
894 return eap_server_method_register(eap);
895 }
896