Line data Source code
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 : int num_chal;
30 : enum {
31 : START, CHALLENGE, REAUTH, NOTIFICATION, SUCCESS, FAILURE
32 : } state;
33 : char *next_pseudonym;
34 : char *next_reauth_id;
35 : u16 counter;
36 : struct eap_sim_reauth *reauth;
37 : u16 notification;
38 : int use_result_ind;
39 : int start_round;
40 : char permanent[20]; /* Permanent username */
41 : };
42 :
43 :
44 168 : static const char * eap_sim_state_txt(int state)
45 : {
46 168 : switch (state) {
47 : case START:
48 42 : return "START";
49 : case CHALLENGE:
50 66 : return "CHALLENGE";
51 : case REAUTH:
52 14 : return "REAUTH";
53 : case SUCCESS:
54 25 : return "SUCCESS";
55 : case FAILURE:
56 15 : return "FAILURE";
57 : case NOTIFICATION:
58 6 : return "NOTIFICATION";
59 : default:
60 0 : return "Unknown?!";
61 : }
62 : }
63 :
64 :
65 84 : static void eap_sim_state(struct eap_sim_data *data, int state)
66 : {
67 168 : wpa_printf(MSG_DEBUG, "EAP-SIM: %s -> %s",
68 84 : eap_sim_state_txt(data->state),
69 : eap_sim_state_txt(state));
70 84 : data->state = state;
71 84 : }
72 :
73 :
74 42 : static void * eap_sim_init(struct eap_sm *sm)
75 : {
76 : struct eap_sim_data *data;
77 :
78 42 : if (sm->eap_sim_db_priv == NULL) {
79 0 : wpa_printf(MSG_WARNING, "EAP-SIM: eap_sim_db not configured");
80 0 : return NULL;
81 : }
82 :
83 42 : data = os_zalloc(sizeof(*data));
84 42 : if (data == NULL)
85 0 : return NULL;
86 42 : data->state = START;
87 :
88 42 : return data;
89 : }
90 :
91 :
92 42 : static void eap_sim_reset(struct eap_sm *sm, void *priv)
93 : {
94 42 : struct eap_sim_data *data = priv;
95 42 : os_free(data->next_pseudonym);
96 42 : os_free(data->next_reauth_id);
97 42 : bin_clear_free(data, sizeof(*data));
98 42 : }
99 :
100 :
101 47 : static struct wpabuf * eap_sim_build_start(struct eap_sm *sm,
102 : struct eap_sim_data *data, u8 id)
103 : {
104 : struct eap_sim_msg *msg;
105 : u8 ver[2];
106 :
107 47 : wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Start");
108 47 : msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM,
109 : EAP_SIM_SUBTYPE_START);
110 47 : data->start_round++;
111 47 : if (data->start_round == 1) {
112 : /*
113 : * RFC 4186, Chap. 4.2.4 recommends that identity from EAP is
114 : * ignored and the SIM/Start is used to request the identity.
115 : */
116 42 : wpa_printf(MSG_DEBUG, " AT_ANY_ID_REQ");
117 42 : eap_sim_msg_add(msg, EAP_SIM_AT_ANY_ID_REQ, 0, NULL, 0);
118 5 : } else if (data->start_round > 3) {
119 : /* Cannot use more than three rounds of Start messages */
120 0 : eap_sim_msg_free(msg);
121 0 : return NULL;
122 5 : } else if (data->start_round == 0) {
123 : /*
124 : * This is a special case that is used to recover from
125 : * AT_COUNTER_TOO_SMALL during re-authentication. Since we
126 : * already know the identity of the peer, there is no need to
127 : * request any identity in this case.
128 : */
129 8 : } else if (sm->identity && sm->identity_len > 0 &&
130 4 : sm->identity[0] == EAP_SIM_REAUTH_ID_PREFIX) {
131 : /* Reauth id may have expired - try fullauth */
132 2 : wpa_printf(MSG_DEBUG, " AT_FULLAUTH_ID_REQ");
133 2 : eap_sim_msg_add(msg, EAP_SIM_AT_FULLAUTH_ID_REQ, 0, NULL, 0);
134 : } else {
135 2 : wpa_printf(MSG_DEBUG, " AT_PERMANENT_ID_REQ");
136 2 : eap_sim_msg_add(msg, EAP_SIM_AT_PERMANENT_ID_REQ, 0, NULL, 0);
137 : }
138 47 : wpa_printf(MSG_DEBUG, " AT_VERSION_LIST");
139 47 : ver[0] = 0;
140 47 : ver[1] = EAP_SIM_VERSION;
141 47 : eap_sim_msg_add(msg, EAP_SIM_AT_VERSION_LIST, sizeof(ver),
142 : ver, sizeof(ver));
143 47 : return eap_sim_msg_finish(msg, EAP_TYPE_SIM, NULL, NULL, 0);
144 : }
145 :
146 :
147 40 : static int eap_sim_build_encr(struct eap_sm *sm, struct eap_sim_data *data,
148 : struct eap_sim_msg *msg, u16 counter,
149 : const u8 *nonce_s)
150 : {
151 40 : os_free(data->next_pseudonym);
152 40 : if (nonce_s == NULL) {
153 33 : data->next_pseudonym =
154 33 : eap_sim_db_get_next_pseudonym(sm->eap_sim_db_priv,
155 : EAP_SIM_DB_SIM);
156 : } else {
157 : /* Do not update pseudonym during re-authentication */
158 7 : data->next_pseudonym = NULL;
159 : }
160 40 : os_free(data->next_reauth_id);
161 40 : if (data->counter <= EAP_SIM_MAX_FAST_REAUTHS) {
162 39 : data->next_reauth_id =
163 39 : eap_sim_db_get_next_reauth_id(sm->eap_sim_db_priv,
164 : EAP_SIM_DB_SIM);
165 : } else {
166 1 : wpa_printf(MSG_DEBUG, "EAP-SIM: Max fast re-authentication "
167 : "count exceeded - force full authentication");
168 1 : data->next_reauth_id = NULL;
169 : }
170 :
171 40 : if (data->next_pseudonym == NULL && data->next_reauth_id == NULL &&
172 0 : counter == 0 && nonce_s == NULL)
173 0 : return 0;
174 :
175 40 : wpa_printf(MSG_DEBUG, " AT_IV");
176 40 : wpa_printf(MSG_DEBUG, " AT_ENCR_DATA");
177 40 : eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV, EAP_SIM_AT_ENCR_DATA);
178 :
179 40 : if (counter > 0) {
180 7 : wpa_printf(MSG_DEBUG, " *AT_COUNTER (%u)", counter);
181 7 : eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, counter, NULL, 0);
182 : }
183 :
184 40 : if (nonce_s) {
185 7 : wpa_printf(MSG_DEBUG, " *AT_NONCE_S");
186 7 : eap_sim_msg_add(msg, EAP_SIM_AT_NONCE_S, 0, nonce_s,
187 : EAP_SIM_NONCE_S_LEN);
188 : }
189 :
190 40 : if (data->next_pseudonym) {
191 33 : wpa_printf(MSG_DEBUG, " *AT_NEXT_PSEUDONYM (%s)",
192 : data->next_pseudonym);
193 66 : eap_sim_msg_add(msg, EAP_SIM_AT_NEXT_PSEUDONYM,
194 33 : os_strlen(data->next_pseudonym),
195 33 : (u8 *) data->next_pseudonym,
196 33 : os_strlen(data->next_pseudonym));
197 : }
198 :
199 40 : if (data->next_reauth_id) {
200 39 : wpa_printf(MSG_DEBUG, " *AT_NEXT_REAUTH_ID (%s)",
201 : data->next_reauth_id);
202 78 : eap_sim_msg_add(msg, EAP_SIM_AT_NEXT_REAUTH_ID,
203 39 : os_strlen(data->next_reauth_id),
204 39 : (u8 *) data->next_reauth_id,
205 39 : os_strlen(data->next_reauth_id));
206 : }
207 :
208 40 : if (eap_sim_msg_add_encr_end(msg, data->k_encr, EAP_SIM_AT_PADDING)) {
209 0 : wpa_printf(MSG_WARNING, "EAP-SIM: Failed to encrypt "
210 : "AT_ENCR_DATA");
211 0 : return -1;
212 : }
213 :
214 40 : return 0;
215 : }
216 :
217 :
218 33 : static struct wpabuf * eap_sim_build_challenge(struct eap_sm *sm,
219 : struct eap_sim_data *data,
220 : u8 id)
221 : {
222 : struct eap_sim_msg *msg;
223 :
224 33 : wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Challenge");
225 33 : msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM,
226 : EAP_SIM_SUBTYPE_CHALLENGE);
227 33 : wpa_printf(MSG_DEBUG, " AT_RAND");
228 33 : eap_sim_msg_add(msg, EAP_SIM_AT_RAND, 0, (u8 *) data->rand,
229 33 : data->num_chal * GSM_RAND_LEN);
230 :
231 33 : if (eap_sim_build_encr(sm, data, msg, 0, NULL)) {
232 0 : eap_sim_msg_free(msg);
233 0 : return NULL;
234 : }
235 :
236 33 : if (sm->eap_sim_aka_result_ind) {
237 32 : wpa_printf(MSG_DEBUG, " AT_RESULT_IND");
238 32 : eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0);
239 : }
240 :
241 33 : wpa_printf(MSG_DEBUG, " AT_MAC");
242 33 : eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
243 33 : return eap_sim_msg_finish(msg, EAP_TYPE_SIM, data->k_aut,
244 33 : data->nonce_mt, EAP_SIM_NONCE_MT_LEN);
245 : }
246 :
247 :
248 7 : static struct wpabuf * eap_sim_build_reauth(struct eap_sm *sm,
249 : struct eap_sim_data *data, u8 id)
250 : {
251 : struct eap_sim_msg *msg;
252 :
253 7 : wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Re-authentication");
254 :
255 7 : if (random_get_bytes(data->nonce_s, EAP_SIM_NONCE_S_LEN))
256 0 : return NULL;
257 7 : wpa_hexdump_key(MSG_MSGDUMP, "EAP-SIM: NONCE_S",
258 7 : data->nonce_s, EAP_SIM_NONCE_S_LEN);
259 :
260 7 : eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut, data->msk,
261 7 : data->emsk);
262 7 : eap_sim_derive_keys_reauth(data->counter, sm->identity,
263 7 : sm->identity_len, data->nonce_s, data->mk,
264 7 : data->msk, data->emsk);
265 :
266 7 : msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM,
267 : EAP_SIM_SUBTYPE_REAUTHENTICATION);
268 :
269 7 : if (eap_sim_build_encr(sm, data, msg, data->counter, data->nonce_s)) {
270 0 : eap_sim_msg_free(msg);
271 0 : return NULL;
272 : }
273 :
274 7 : if (sm->eap_sim_aka_result_ind) {
275 7 : wpa_printf(MSG_DEBUG, " AT_RESULT_IND");
276 7 : eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0);
277 : }
278 :
279 7 : wpa_printf(MSG_DEBUG, " AT_MAC");
280 7 : eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
281 7 : return eap_sim_msg_finish(msg, EAP_TYPE_SIM, data->k_aut, NULL, 0);
282 : }
283 :
284 :
285 3 : static struct wpabuf * eap_sim_build_notification(struct eap_sm *sm,
286 : struct eap_sim_data *data,
287 : u8 id)
288 : {
289 : struct eap_sim_msg *msg;
290 :
291 3 : wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Notification");
292 3 : msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM,
293 : EAP_SIM_SUBTYPE_NOTIFICATION);
294 3 : wpa_printf(MSG_DEBUG, " AT_NOTIFICATION (%d)", data->notification);
295 3 : eap_sim_msg_add(msg, EAP_SIM_AT_NOTIFICATION, data->notification,
296 : NULL, 0);
297 3 : if (data->use_result_ind) {
298 2 : if (data->reauth) {
299 1 : wpa_printf(MSG_DEBUG, " AT_IV");
300 1 : wpa_printf(MSG_DEBUG, " AT_ENCR_DATA");
301 1 : eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV,
302 : EAP_SIM_AT_ENCR_DATA);
303 1 : wpa_printf(MSG_DEBUG, " *AT_COUNTER (%u)",
304 1 : data->counter);
305 1 : eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, data->counter,
306 : NULL, 0);
307 :
308 1 : if (eap_sim_msg_add_encr_end(msg, data->k_encr,
309 : EAP_SIM_AT_PADDING)) {
310 0 : wpa_printf(MSG_WARNING, "EAP-SIM: Failed to "
311 : "encrypt AT_ENCR_DATA");
312 0 : eap_sim_msg_free(msg);
313 0 : return NULL;
314 : }
315 : }
316 :
317 2 : wpa_printf(MSG_DEBUG, " AT_MAC");
318 2 : eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
319 : }
320 3 : return eap_sim_msg_finish(msg, EAP_TYPE_SIM, data->k_aut, NULL, 0);
321 : }
322 :
323 :
324 90 : static struct wpabuf * eap_sim_buildReq(struct eap_sm *sm, void *priv, u8 id)
325 : {
326 90 : struct eap_sim_data *data = priv;
327 :
328 90 : switch (data->state) {
329 : case START:
330 47 : return eap_sim_build_start(sm, data, id);
331 : case CHALLENGE:
332 33 : return eap_sim_build_challenge(sm, data, id);
333 : case REAUTH:
334 7 : return eap_sim_build_reauth(sm, data, id);
335 : case NOTIFICATION:
336 3 : return eap_sim_build_notification(sm, data, id);
337 : default:
338 0 : wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown state %d in "
339 0 : "buildReq", data->state);
340 0 : break;
341 : }
342 0 : return NULL;
343 : }
344 :
345 :
346 88 : static Boolean eap_sim_check(struct eap_sm *sm, void *priv,
347 : struct wpabuf *respData)
348 : {
349 : const u8 *pos;
350 : size_t len;
351 :
352 88 : pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SIM, respData, &len);
353 88 : if (pos == NULL || len < 3) {
354 0 : wpa_printf(MSG_INFO, "EAP-SIM: Invalid frame");
355 0 : return TRUE;
356 : }
357 :
358 88 : return FALSE;
359 : }
360 :
361 :
362 122 : static Boolean eap_sim_unexpected_subtype(struct eap_sim_data *data,
363 : u8 subtype)
364 : {
365 122 : if (subtype == EAP_SIM_SUBTYPE_CLIENT_ERROR)
366 14 : return FALSE;
367 :
368 108 : switch (data->state) {
369 : case START:
370 79 : if (subtype != EAP_SIM_SUBTYPE_START) {
371 0 : wpa_printf(MSG_INFO, "EAP-SIM: Unexpected response "
372 : "subtype %d", subtype);
373 0 : return TRUE;
374 : }
375 79 : break;
376 : case CHALLENGE:
377 20 : if (subtype != EAP_SIM_SUBTYPE_CHALLENGE) {
378 0 : wpa_printf(MSG_INFO, "EAP-SIM: Unexpected response "
379 : "subtype %d", subtype);
380 0 : return TRUE;
381 : }
382 20 : break;
383 : case REAUTH:
384 6 : if (subtype != EAP_SIM_SUBTYPE_REAUTHENTICATION) {
385 0 : wpa_printf(MSG_INFO, "EAP-SIM: Unexpected response "
386 : "subtype %d", subtype);
387 0 : return TRUE;
388 : }
389 6 : break;
390 : case NOTIFICATION:
391 3 : if (subtype != EAP_SIM_SUBTYPE_NOTIFICATION) {
392 0 : wpa_printf(MSG_INFO, "EAP-SIM: Unexpected response "
393 : "subtype %d", subtype);
394 0 : return TRUE;
395 : }
396 3 : break;
397 : default:
398 0 : wpa_printf(MSG_INFO, "EAP-SIM: Unexpected state (%d) for "
399 0 : "processing a response", data->state);
400 0 : return TRUE;
401 : }
402 :
403 108 : return FALSE;
404 : }
405 :
406 :
407 68 : static int eap_sim_supported_ver(struct eap_sim_data *data, int version)
408 : {
409 68 : return version == EAP_SIM_VERSION;
410 : }
411 :
412 :
413 79 : static void eap_sim_process_start(struct eap_sm *sm,
414 : struct eap_sim_data *data,
415 : struct wpabuf *respData,
416 : struct eap_sim_attrs *attr)
417 : {
418 : size_t identity_len;
419 : u8 ver_list[2];
420 : u8 *new_identity;
421 : char *username;
422 :
423 79 : wpa_printf(MSG_DEBUG, "EAP-SIM: Receive start response");
424 :
425 79 : if (data->start_round == 0) {
426 : /*
427 : * Special case for AT_COUNTER_TOO_SMALL recovery - no identity
428 : * was requested since we already know it.
429 : */
430 2 : goto skip_id_update;
431 : }
432 :
433 : /*
434 : * We always request identity in SIM/Start, so the peer is required to
435 : * have replied with one.
436 : */
437 77 : if (!attr->identity || attr->identity_len == 0) {
438 0 : wpa_printf(MSG_DEBUG, "EAP-SIM: Peer did not provide any "
439 : "identity");
440 0 : goto failed;
441 : }
442 :
443 77 : new_identity = os_malloc(attr->identity_len);
444 77 : if (new_identity == NULL)
445 0 : goto failed;
446 77 : os_free(sm->identity);
447 77 : sm->identity = new_identity;
448 77 : os_memcpy(sm->identity, attr->identity, attr->identity_len);
449 77 : sm->identity_len = attr->identity_len;
450 :
451 154 : wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Identity",
452 77 : sm->identity, sm->identity_len);
453 77 : username = sim_get_username(sm->identity, sm->identity_len);
454 77 : if (username == NULL)
455 0 : goto failed;
456 :
457 77 : if (username[0] == EAP_SIM_REAUTH_ID_PREFIX) {
458 9 : wpa_printf(MSG_DEBUG, "EAP-SIM: Reauth username '%s'",
459 : username);
460 9 : data->reauth = eap_sim_db_get_reauth_entry(
461 : sm->eap_sim_db_priv, username);
462 9 : os_free(username);
463 9 : if (data->reauth == NULL) {
464 2 : wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown reauth "
465 : "identity - request full auth identity");
466 : /* Remain in START state for another round */
467 2 : return;
468 : }
469 7 : wpa_printf(MSG_DEBUG, "EAP-SIM: Using fast re-authentication");
470 7 : os_strlcpy(data->permanent, data->reauth->permanent,
471 : sizeof(data->permanent));
472 7 : data->counter = data->reauth->counter;
473 7 : os_memcpy(data->mk, data->reauth->mk, EAP_SIM_MK_LEN);
474 7 : eap_sim_state(data, REAUTH);
475 7 : return;
476 : }
477 :
478 68 : if (username[0] == EAP_SIM_PSEUDONYM_PREFIX) {
479 : const char *permanent;
480 4 : wpa_printf(MSG_DEBUG, "EAP-SIM: Pseudonym username '%s'",
481 : username);
482 4 : permanent = eap_sim_db_get_permanent(
483 : sm->eap_sim_db_priv, username);
484 4 : os_free(username);
485 4 : if (permanent == NULL) {
486 2 : wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown pseudonym "
487 : "identity - request permanent identity");
488 : /* Remain in START state for another round */
489 2 : return;
490 : }
491 2 : os_strlcpy(data->permanent, permanent,
492 : sizeof(data->permanent));
493 64 : } else if (username[0] == EAP_SIM_PERMANENT_PREFIX) {
494 64 : wpa_printf(MSG_DEBUG, "EAP-SIM: Permanent username '%s'",
495 : username);
496 64 : os_strlcpy(data->permanent, username, sizeof(data->permanent));
497 64 : os_free(username);
498 : } else {
499 0 : wpa_printf(MSG_DEBUG, "EAP-SIM: Unrecognized username '%s'",
500 : username);
501 0 : os_free(username);
502 0 : goto failed;
503 : }
504 :
505 : skip_id_update:
506 : /* Full authentication */
507 :
508 68 : if (attr->nonce_mt == NULL || attr->selected_version < 0) {
509 0 : wpa_printf(MSG_DEBUG, "EAP-SIM: Start/Response missing "
510 : "required attributes");
511 0 : goto failed;
512 : }
513 :
514 68 : if (!eap_sim_supported_ver(data, attr->selected_version)) {
515 0 : wpa_printf(MSG_DEBUG, "EAP-SIM: Peer selected unsupported "
516 : "version %d", attr->selected_version);
517 0 : goto failed;
518 : }
519 :
520 68 : data->counter = 0; /* reset re-auth counter since this is full auth */
521 68 : data->reauth = NULL;
522 :
523 68 : data->num_chal = eap_sim_db_get_gsm_triplets(
524 68 : sm->eap_sim_db_priv, data->permanent, EAP_SIM_MAX_CHAL,
525 68 : (u8 *) data->rand, (u8 *) data->kc, (u8 *) data->sres, sm);
526 68 : if (data->num_chal == EAP_SIM_DB_PENDING) {
527 34 : wpa_printf(MSG_DEBUG, "EAP-SIM: GSM authentication triplets "
528 : "not yet available - pending request");
529 34 : sm->method_pending = METHOD_PENDING_WAIT;
530 34 : return;
531 : }
532 34 : if (data->num_chal < 2) {
533 1 : wpa_printf(MSG_INFO, "EAP-SIM: Failed to get GSM "
534 : "authentication triplets for the peer");
535 1 : goto failed;
536 : }
537 :
538 33 : identity_len = sm->identity_len;
539 66 : while (identity_len > 0 && sm->identity[identity_len - 1] == '\0') {
540 0 : wpa_printf(MSG_DEBUG, "EAP-SIM: Workaround - drop last null "
541 : "character from identity");
542 0 : identity_len--;
543 : }
544 33 : wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Identity for MK derivation",
545 33 : sm->identity, identity_len);
546 :
547 33 : os_memcpy(data->nonce_mt, attr->nonce_mt, EAP_SIM_NONCE_MT_LEN);
548 33 : WPA_PUT_BE16(ver_list, EAP_SIM_VERSION);
549 66 : eap_sim_derive_mk(sm->identity, identity_len, attr->nonce_mt,
550 33 : attr->selected_version, ver_list, sizeof(ver_list),
551 33 : data->num_chal, (const u8 *) data->kc, data->mk);
552 33 : eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut, data->msk,
553 33 : data->emsk);
554 :
555 33 : eap_sim_state(data, CHALLENGE);
556 33 : return;
557 :
558 : failed:
559 1 : data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
560 1 : eap_sim_state(data, NOTIFICATION);
561 : }
562 :
563 :
564 20 : static void eap_sim_process_challenge(struct eap_sm *sm,
565 : struct eap_sim_data *data,
566 : struct wpabuf *respData,
567 : struct eap_sim_attrs *attr)
568 : {
569 40 : if (attr->mac == NULL ||
570 40 : eap_sim_verify_mac(data->k_aut, respData, attr->mac,
571 20 : (u8 *) data->sres,
572 20 : data->num_chal * EAP_SIM_SRES_LEN)) {
573 0 : wpa_printf(MSG_WARNING, "EAP-SIM: Challenge message "
574 : "did not include valid AT_MAC");
575 0 : data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
576 0 : eap_sim_state(data, NOTIFICATION);
577 20 : return;
578 : }
579 :
580 20 : wpa_printf(MSG_DEBUG, "EAP-SIM: Challenge response includes the "
581 : "correct AT_MAC");
582 20 : if (sm->eap_sim_aka_result_ind && attr->result_ind) {
583 1 : data->use_result_ind = 1;
584 1 : data->notification = EAP_SIM_SUCCESS;
585 1 : eap_sim_state(data, NOTIFICATION);
586 : } else
587 19 : eap_sim_state(data, SUCCESS);
588 :
589 20 : if (data->next_pseudonym) {
590 20 : eap_sim_db_add_pseudonym(sm->eap_sim_db_priv, data->permanent,
591 : data->next_pseudonym);
592 20 : data->next_pseudonym = NULL;
593 : }
594 20 : if (data->next_reauth_id) {
595 20 : eap_sim_db_add_reauth(sm->eap_sim_db_priv, data->permanent,
596 20 : data->next_reauth_id, data->counter + 1,
597 20 : data->mk);
598 20 : data->next_reauth_id = NULL;
599 : }
600 : }
601 :
602 :
603 6 : static void eap_sim_process_reauth(struct eap_sm *sm,
604 : struct eap_sim_data *data,
605 : struct wpabuf *respData,
606 : struct eap_sim_attrs *attr)
607 : {
608 : struct eap_sim_attrs eattr;
609 6 : u8 *decrypted = NULL;
610 :
611 12 : if (attr->mac == NULL ||
612 6 : eap_sim_verify_mac(data->k_aut, respData, attr->mac, data->nonce_s,
613 : EAP_SIM_NONCE_S_LEN)) {
614 0 : wpa_printf(MSG_WARNING, "EAP-SIM: Re-authentication message "
615 : "did not include valid AT_MAC");
616 0 : goto fail;
617 : }
618 :
619 6 : if (attr->encr_data == NULL || attr->iv == NULL) {
620 0 : wpa_printf(MSG_WARNING, "EAP-SIM: Reauthentication "
621 : "message did not include encrypted data");
622 0 : goto fail;
623 : }
624 :
625 6 : decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
626 : attr->encr_data_len, attr->iv, &eattr,
627 : 0);
628 6 : if (decrypted == NULL) {
629 0 : wpa_printf(MSG_WARNING, "EAP-SIM: Failed to parse encrypted "
630 : "data from reauthentication message");
631 0 : goto fail;
632 : }
633 :
634 6 : if (eattr.counter != data->counter) {
635 0 : wpa_printf(MSG_WARNING, "EAP-SIM: Re-authentication message "
636 : "used incorrect counter %u, expected %u",
637 0 : eattr.counter, data->counter);
638 0 : goto fail;
639 : }
640 6 : os_free(decrypted);
641 6 : decrypted = NULL;
642 :
643 6 : wpa_printf(MSG_DEBUG, "EAP-SIM: Re-authentication response includes "
644 : "the correct AT_MAC");
645 :
646 6 : if (eattr.counter_too_small) {
647 1 : wpa_printf(MSG_DEBUG, "EAP-AKA: Re-authentication response "
648 : "included AT_COUNTER_TOO_SMALL - starting full "
649 : "authentication");
650 1 : data->start_round = -1;
651 1 : eap_sim_state(data, START);
652 1 : return;
653 : }
654 :
655 5 : if (sm->eap_sim_aka_result_ind && attr->result_ind) {
656 1 : data->use_result_ind = 1;
657 1 : data->notification = EAP_SIM_SUCCESS;
658 1 : eap_sim_state(data, NOTIFICATION);
659 : } else
660 4 : eap_sim_state(data, SUCCESS);
661 :
662 5 : if (data->next_reauth_id) {
663 4 : eap_sim_db_add_reauth(sm->eap_sim_db_priv, data->permanent,
664 : data->next_reauth_id,
665 4 : data->counter + 1, data->mk);
666 4 : data->next_reauth_id = NULL;
667 : } else {
668 1 : eap_sim_db_remove_reauth(sm->eap_sim_db_priv, data->reauth);
669 1 : data->reauth = NULL;
670 : }
671 :
672 5 : return;
673 :
674 : fail:
675 0 : data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
676 0 : eap_sim_state(data, NOTIFICATION);
677 0 : eap_sim_db_remove_reauth(sm->eap_sim_db_priv, data->reauth);
678 0 : data->reauth = NULL;
679 0 : os_free(decrypted);
680 : }
681 :
682 :
683 14 : static void eap_sim_process_client_error(struct eap_sm *sm,
684 : struct eap_sim_data *data,
685 : struct wpabuf *respData,
686 : struct eap_sim_attrs *attr)
687 : {
688 14 : wpa_printf(MSG_DEBUG, "EAP-SIM: Client reported error %d",
689 : attr->client_error_code);
690 14 : if (data->notification == EAP_SIM_SUCCESS && data->use_result_ind)
691 0 : eap_sim_state(data, SUCCESS);
692 : else
693 14 : eap_sim_state(data, FAILURE);
694 14 : }
695 :
696 :
697 3 : static void eap_sim_process_notification(struct eap_sm *sm,
698 : struct eap_sim_data *data,
699 : struct wpabuf *respData,
700 : struct eap_sim_attrs *attr)
701 : {
702 3 : wpa_printf(MSG_DEBUG, "EAP-SIM: Client replied to notification");
703 3 : if (data->notification == EAP_SIM_SUCCESS && data->use_result_ind)
704 2 : eap_sim_state(data, SUCCESS);
705 : else
706 1 : eap_sim_state(data, FAILURE);
707 3 : }
708 :
709 :
710 122 : static void eap_sim_process(struct eap_sm *sm, void *priv,
711 : struct wpabuf *respData)
712 : {
713 122 : struct eap_sim_data *data = priv;
714 : const u8 *pos, *end;
715 : u8 subtype;
716 : size_t len;
717 : struct eap_sim_attrs attr;
718 :
719 122 : pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SIM, respData, &len);
720 122 : if (pos == NULL || len < 3)
721 14 : return;
722 :
723 122 : end = pos + len;
724 122 : subtype = *pos;
725 122 : pos += 3;
726 :
727 122 : if (eap_sim_unexpected_subtype(data, subtype)) {
728 0 : wpa_printf(MSG_DEBUG, "EAP-SIM: Unrecognized or unexpected "
729 : "EAP-SIM Subtype in EAP Response");
730 0 : data->notification = EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
731 0 : eap_sim_state(data, NOTIFICATION);
732 0 : return;
733 : }
734 :
735 122 : if (eap_sim_parse_attr(pos, end, &attr, 0, 0)) {
736 0 : wpa_printf(MSG_DEBUG, "EAP-SIM: Failed to parse attributes");
737 0 : if (subtype != EAP_SIM_SUBTYPE_CLIENT_ERROR &&
738 0 : (data->state == START || data->state == CHALLENGE ||
739 0 : data->state == REAUTH)) {
740 0 : data->notification =
741 : EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH;
742 0 : eap_sim_state(data, NOTIFICATION);
743 0 : return;
744 : }
745 0 : eap_sim_state(data, FAILURE);
746 0 : return;
747 : }
748 :
749 122 : if (subtype == EAP_SIM_SUBTYPE_CLIENT_ERROR) {
750 14 : eap_sim_process_client_error(sm, data, respData, &attr);
751 14 : return;
752 : }
753 :
754 108 : switch (data->state) {
755 : case START:
756 79 : eap_sim_process_start(sm, data, respData, &attr);
757 79 : break;
758 : case CHALLENGE:
759 20 : eap_sim_process_challenge(sm, data, respData, &attr);
760 20 : break;
761 : case REAUTH:
762 6 : eap_sim_process_reauth(sm, data, respData, &attr);
763 6 : break;
764 : case NOTIFICATION:
765 3 : eap_sim_process_notification(sm, data, respData, &attr);
766 3 : break;
767 : default:
768 0 : wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown state %d in "
769 0 : "process", data->state);
770 0 : break;
771 : }
772 : }
773 :
774 :
775 137 : static Boolean eap_sim_isDone(struct eap_sm *sm, void *priv)
776 : {
777 137 : struct eap_sim_data *data = priv;
778 137 : return data->state == SUCCESS || data->state == FAILURE;
779 : }
780 :
781 :
782 40 : static u8 * eap_sim_getKey(struct eap_sm *sm, void *priv, size_t *len)
783 : {
784 40 : struct eap_sim_data *data = priv;
785 : u8 *key;
786 :
787 40 : if (data->state != SUCCESS)
788 15 : return NULL;
789 :
790 25 : key = os_malloc(EAP_SIM_KEYING_DATA_LEN);
791 25 : if (key == NULL)
792 0 : return NULL;
793 25 : os_memcpy(key, data->msk, EAP_SIM_KEYING_DATA_LEN);
794 25 : *len = EAP_SIM_KEYING_DATA_LEN;
795 25 : return key;
796 : }
797 :
798 :
799 1 : static u8 * eap_sim_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
800 : {
801 1 : struct eap_sim_data *data = priv;
802 : u8 *key;
803 :
804 1 : if (data->state != SUCCESS)
805 0 : return NULL;
806 :
807 1 : key = os_malloc(EAP_EMSK_LEN);
808 1 : if (key == NULL)
809 0 : return NULL;
810 1 : os_memcpy(key, data->emsk, EAP_EMSK_LEN);
811 1 : *len = EAP_EMSK_LEN;
812 1 : return key;
813 : }
814 :
815 :
816 55 : static Boolean eap_sim_isSuccess(struct eap_sm *sm, void *priv)
817 : {
818 55 : struct eap_sim_data *data = priv;
819 55 : return data->state == SUCCESS;
820 : }
821 :
822 :
823 40 : static u8 * eap_sim_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
824 : {
825 40 : struct eap_sim_data *data = priv;
826 : u8 *id;
827 :
828 40 : if (data->state != SUCCESS)
829 15 : return NULL;
830 :
831 25 : *len = 1 + data->num_chal * GSM_RAND_LEN + EAP_SIM_NONCE_MT_LEN;
832 25 : id = os_malloc(*len);
833 25 : if (id == NULL)
834 0 : return NULL;
835 :
836 25 : id[0] = EAP_TYPE_SIM;
837 25 : os_memcpy(id + 1, data->rand, data->num_chal * GSM_RAND_LEN);
838 25 : os_memcpy(id + 1 + data->num_chal * GSM_RAND_LEN, data->nonce_mt,
839 : EAP_SIM_NONCE_MT_LEN);
840 25 : wpa_hexdump(MSG_DEBUG, "EAP-SIM: Derived Session-Id", id, *len);
841 :
842 25 : return id;
843 : }
844 :
845 :
846 10 : int eap_server_sim_register(void)
847 : {
848 : struct eap_method *eap;
849 : int ret;
850 :
851 10 : eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
852 : EAP_VENDOR_IETF, EAP_TYPE_SIM, "SIM");
853 10 : if (eap == NULL)
854 0 : return -1;
855 :
856 10 : eap->init = eap_sim_init;
857 10 : eap->reset = eap_sim_reset;
858 10 : eap->buildReq = eap_sim_buildReq;
859 10 : eap->check = eap_sim_check;
860 10 : eap->process = eap_sim_process;
861 10 : eap->isDone = eap_sim_isDone;
862 10 : eap->getKey = eap_sim_getKey;
863 10 : eap->isSuccess = eap_sim_isSuccess;
864 10 : eap->get_emsk = eap_sim_get_emsk;
865 10 : eap->getSessionId = eap_sim_get_session_id;
866 :
867 10 : ret = eap_server_method_register(eap);
868 10 : if (ret)
869 0 : eap_server_method_free(eap);
870 10 : return ret;
871 : }
|
