1 /*
2 * EAP peer method: EAP-SIM (RFC 4186)
3 * Copyright (c) 2004-2012, 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 "pcsc_funcs.h"
13 #include "crypto/milenage.h"
14 #include "crypto/random.h"
15 #include "eap_peer/eap_i.h"
16 #include "eap_config.h"
17 #include "eap_common/eap_sim_common.h"
18
19
20 struct eap_sim_data {
21 u8 *ver_list;
22 size_t ver_list_len;
23 int selected_version;
24 size_t min_num_chal, num_chal;
25
26 u8 kc[3][EAP_SIM_KC_LEN];
27 u8 sres[3][EAP_SIM_SRES_LEN];
28 u8 nonce_mt[EAP_SIM_NONCE_MT_LEN], nonce_s[EAP_SIM_NONCE_S_LEN];
29 u8 mk[EAP_SIM_MK_LEN];
30 u8 k_aut[EAP_SIM_K_AUT_LEN];
31 u8 k_encr[EAP_SIM_K_ENCR_LEN];
32 u8 msk[EAP_SIM_KEYING_DATA_LEN];
33 u8 emsk[EAP_EMSK_LEN];
34 u8 rand[3][GSM_RAND_LEN];
35
36 int num_id_req, num_notification;
37 u8 *pseudonym;
38 size_t pseudonym_len;
39 u8 *reauth_id;
40 size_t reauth_id_len;
41 int reauth;
42 unsigned int counter, counter_too_small;
43 u8 *last_eap_identity;
44 size_t last_eap_identity_len;
45 enum {
46 CONTINUE, RESULT_SUCCESS, RESULT_FAILURE, SUCCESS, FAILURE
47 } state;
48 int result_ind, use_result_ind;
49 };
50
51
52 #ifndef CONFIG_NO_STDOUT_DEBUG
eap_sim_state_txt(int state)53 static const char * eap_sim_state_txt(int state)
54 {
55 switch (state) {
56 case CONTINUE:
57 return "CONTINUE";
58 case RESULT_SUCCESS:
59 return "RESULT_SUCCESS";
60 case RESULT_FAILURE:
61 return "RESULT_FAILURE";
62 case SUCCESS:
63 return "SUCCESS";
64 case FAILURE:
65 return "FAILURE";
66 default:
67 return "?";
68 }
69 }
70 #endif /* CONFIG_NO_STDOUT_DEBUG */
71
72
eap_sim_state(struct eap_sim_data * data,int state)73 static void eap_sim_state(struct eap_sim_data *data, int state)
74 {
75 wpa_printf(MSG_DEBUG, "EAP-SIM: %s -> %s",
76 eap_sim_state_txt(data->state),
77 eap_sim_state_txt(state));
78 data->state = state;
79 }
80
81
eap_sim_init(struct eap_sm * sm)82 static void * eap_sim_init(struct eap_sm *sm)
83 {
84 struct eap_sim_data *data;
85 struct eap_peer_config *config = eap_get_config(sm);
86
87 data = os_zalloc(sizeof(*data));
88 if (data == NULL)
89 return NULL;
90
91 if (random_get_bytes(data->nonce_mt, EAP_SIM_NONCE_MT_LEN)) {
92 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to get random data "
93 "for NONCE_MT");
94 os_free(data);
95 return NULL;
96 }
97
98 data->min_num_chal = 2;
99 if (config && config->phase1) {
100 char *pos = os_strstr(config->phase1, "sim_min_num_chal=");
101 if (pos) {
102 data->min_num_chal = atoi(pos + 17);
103 if (data->min_num_chal < 2 || data->min_num_chal > 3) {
104 wpa_printf(MSG_WARNING, "EAP-SIM: Invalid "
105 "sim_min_num_chal configuration "
106 "(%lu, expected 2 or 3)",
107 (unsigned long) data->min_num_chal);
108 os_free(data);
109 return NULL;
110 }
111 wpa_printf(MSG_DEBUG, "EAP-SIM: Set minimum number of "
112 "challenges to %lu",
113 (unsigned long) data->min_num_chal);
114 }
115
116 data->result_ind = os_strstr(config->phase1, "result_ind=1") !=
117 NULL;
118 }
119
120 if (config && config->anonymous_identity) {
121 data->pseudonym = os_malloc(config->anonymous_identity_len);
122 if (data->pseudonym) {
123 os_memcpy(data->pseudonym, config->anonymous_identity,
124 config->anonymous_identity_len);
125 data->pseudonym_len = config->anonymous_identity_len;
126 }
127 }
128
129 eap_sim_state(data, CONTINUE);
130
131 return data;
132 }
133
134
eap_sim_deinit(struct eap_sm * sm,void * priv)135 static void eap_sim_deinit(struct eap_sm *sm, void *priv)
136 {
137 struct eap_sim_data *data = priv;
138 if (data) {
139 os_free(data->ver_list);
140 os_free(data->pseudonym);
141 os_free(data->reauth_id);
142 os_free(data->last_eap_identity);
143 os_free(data);
144 }
145 }
146
147
eap_sim_gsm_auth(struct eap_sm * sm,struct eap_sim_data * data)148 static int eap_sim_gsm_auth(struct eap_sm *sm, struct eap_sim_data *data)
149 {
150 struct eap_peer_config *conf;
151
152 wpa_printf(MSG_DEBUG, "EAP-SIM: GSM authentication algorithm");
153
154 conf = eap_get_config(sm);
155 if (conf == NULL)
156 return -1;
157 if (conf->pcsc) {
158 if (scard_gsm_auth(sm->scard_ctx, data->rand[0],
159 data->sres[0], data->kc[0]) ||
160 scard_gsm_auth(sm->scard_ctx, data->rand[1],
161 data->sres[1], data->kc[1]) ||
162 (data->num_chal > 2 &&
163 scard_gsm_auth(sm->scard_ctx, data->rand[2],
164 data->sres[2], data->kc[2]))) {
165 wpa_printf(MSG_DEBUG, "EAP-SIM: GSM SIM "
166 "authentication could not be completed");
167 return -1;
168 }
169 return 0;
170 }
171
172 #ifdef CONFIG_SIM_SIMULATOR
173 if (conf->password) {
174 u8 opc[16], k[16];
175 const char *pos;
176 size_t i;
177 wpa_printf(MSG_DEBUG, "EAP-SIM: Use internal GSM-Milenage "
178 "implementation for authentication");
179 if (conf->password_len < 65) {
180 wpa_printf(MSG_DEBUG, "EAP-SIM: invalid GSM-Milenage "
181 "password");
182 return -1;
183 }
184 pos = (const char *) conf->password;
185 if (hexstr2bin(pos, k, 16))
186 return -1;
187 pos += 32;
188 if (*pos != ':')
189 return -1;
190 pos++;
191
192 if (hexstr2bin(pos, opc, 16))
193 return -1;
194
195 for (i = 0; i < data->num_chal; i++) {
196 if (gsm_milenage(opc, k, data->rand[i],
197 data->sres[i], data->kc[i])) {
198 wpa_printf(MSG_DEBUG, "EAP-SIM: "
199 "GSM-Milenage authentication "
200 "could not be completed");
201 return -1;
202 }
203 wpa_hexdump(MSG_DEBUG, "EAP-SIM: RAND",
204 data->rand[i], GSM_RAND_LEN);
205 wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: SRES",
206 data->sres[i], EAP_SIM_SRES_LEN);
207 wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: Kc",
208 data->kc[i], EAP_SIM_KC_LEN);
209 }
210 return 0;
211 }
212 #endif /* CONFIG_SIM_SIMULATOR */
213
214 #ifdef CONFIG_SIM_HARDCODED
215 /* These hardcoded Kc and SRES values are used for testing. RAND to
216 * KC/SREC mapping is very bogus as far as real authentication is
217 * concerned, but it is quite useful for cases where the AS is rotating
218 * the order of pre-configured values. */
219 {
220 size_t i;
221
222 wpa_printf(MSG_DEBUG, "EAP-SIM: Use hardcoded Kc and SRES "
223 "values for testing");
224
225 for (i = 0; i < data->num_chal; i++) {
226 if (data->rand[i][0] == 0xaa) {
227 os_memcpy(data->kc[i],
228 "\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7",
229 EAP_SIM_KC_LEN);
230 os_memcpy(data->sres[i], "\xd1\xd2\xd3\xd4",
231 EAP_SIM_SRES_LEN);
232 } else if (data->rand[i][0] == 0xbb) {
233 os_memcpy(data->kc[i],
234 "\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7",
235 EAP_SIM_KC_LEN);
236 os_memcpy(data->sres[i], "\xe1\xe2\xe3\xe4",
237 EAP_SIM_SRES_LEN);
238 } else {
239 os_memcpy(data->kc[i],
240 "\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7",
241 EAP_SIM_KC_LEN);
242 os_memcpy(data->sres[i], "\xf1\xf2\xf3\xf4",
243 EAP_SIM_SRES_LEN);
244 }
245 }
246 }
247
248 return 0;
249
250 #else /* CONFIG_SIM_HARDCODED */
251
252 wpa_printf(MSG_DEBUG, "EAP-SIM: No GSM authentication algorithm "
253 "enabled");
254 return -1;
255
256 #endif /* CONFIG_SIM_HARDCODED */
257 }
258
259
eap_sim_supported_ver(int version)260 static int eap_sim_supported_ver(int version)
261 {
262 return version == EAP_SIM_VERSION;
263 }
264
265
266 #define CLEAR_PSEUDONYM 0x01
267 #define CLEAR_REAUTH_ID 0x02
268 #define CLEAR_EAP_ID 0x04
269
eap_sim_clear_identities(struct eap_sm * sm,struct eap_sim_data * data,int id)270 static void eap_sim_clear_identities(struct eap_sm *sm,
271 struct eap_sim_data *data, int id)
272 {
273 if ((id & CLEAR_PSEUDONYM) && data->pseudonym) {
274 wpa_printf(MSG_DEBUG, "EAP-SIM: forgetting old pseudonym");
275 os_free(data->pseudonym);
276 data->pseudonym = NULL;
277 data->pseudonym_len = 0;
278 eap_set_anon_id(sm, NULL, 0);
279 }
280 if ((id & CLEAR_REAUTH_ID) && data->reauth_id) {
281 wpa_printf(MSG_DEBUG, "EAP-SIM: forgetting old reauth_id");
282 os_free(data->reauth_id);
283 data->reauth_id = NULL;
284 data->reauth_id_len = 0;
285 }
286 if ((id & CLEAR_EAP_ID) && data->last_eap_identity) {
287 wpa_printf(MSG_DEBUG, "EAP-SIM: forgetting old eap_id");
288 os_free(data->last_eap_identity);
289 data->last_eap_identity = NULL;
290 data->last_eap_identity_len = 0;
291 }
292 }
293
294
eap_sim_learn_ids(struct eap_sm * sm,struct eap_sim_data * data,struct eap_sim_attrs * attr)295 static int eap_sim_learn_ids(struct eap_sm *sm, struct eap_sim_data *data,
296 struct eap_sim_attrs *attr)
297 {
298 if (attr->next_pseudonym) {
299 const u8 *identity = NULL;
300 size_t identity_len = 0;
301 const u8 *realm = NULL;
302 size_t realm_len = 0;
303
304 wpa_hexdump_ascii(MSG_DEBUG,
305 "EAP-SIM: (encr) AT_NEXT_PSEUDONYM",
306 attr->next_pseudonym,
307 attr->next_pseudonym_len);
308 os_free(data->pseudonym);
309 /* Look for the realm of the permanent identity */
310 identity = eap_get_config_identity(sm, &identity_len);
311 if (identity) {
312 for (realm = identity, realm_len = identity_len;
313 realm_len > 0; realm_len--, realm++) {
314 if (*realm == '@')
315 break;
316 }
317 }
318 data->pseudonym = os_malloc(attr->next_pseudonym_len +
319 realm_len);
320 if (data->pseudonym == NULL) {
321 wpa_printf(MSG_INFO, "EAP-SIM: (encr) No memory for "
322 "next pseudonym");
323 data->pseudonym_len = 0;
324 return -1;
325 }
326 os_memcpy(data->pseudonym, attr->next_pseudonym,
327 attr->next_pseudonym_len);
328 if (realm_len) {
329 os_memcpy(data->pseudonym + attr->next_pseudonym_len,
330 realm, realm_len);
331 }
332 data->pseudonym_len = attr->next_pseudonym_len + realm_len;
333 eap_set_anon_id(sm, data->pseudonym, data->pseudonym_len);
334 }
335
336 if (attr->next_reauth_id) {
337 os_free(data->reauth_id);
338 data->reauth_id = os_malloc(attr->next_reauth_id_len);
339 if (data->reauth_id == NULL) {
340 wpa_printf(MSG_INFO, "EAP-SIM: (encr) No memory for "
341 "next reauth_id");
342 data->reauth_id_len = 0;
343 return -1;
344 }
345 os_memcpy(data->reauth_id, attr->next_reauth_id,
346 attr->next_reauth_id_len);
347 data->reauth_id_len = attr->next_reauth_id_len;
348 wpa_hexdump_ascii(MSG_DEBUG,
349 "EAP-SIM: (encr) AT_NEXT_REAUTH_ID",
350 data->reauth_id,
351 data->reauth_id_len);
352 }
353
354 return 0;
355 }
356
357
eap_sim_client_error(struct eap_sim_data * data,u8 id,int err)358 static struct wpabuf * eap_sim_client_error(struct eap_sim_data *data, u8 id,
359 int err)
360 {
361 struct eap_sim_msg *msg;
362
363 eap_sim_state(data, FAILURE);
364 data->num_id_req = 0;
365 data->num_notification = 0;
366
367 wpa_printf(MSG_DEBUG, "EAP-SIM: Send Client-Error (error code %d)",
368 err);
369 msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, EAP_TYPE_SIM,
370 EAP_SIM_SUBTYPE_CLIENT_ERROR);
371 eap_sim_msg_add(msg, EAP_SIM_AT_CLIENT_ERROR_CODE, err, NULL, 0);
372 return eap_sim_msg_finish(msg, NULL, NULL, 0);
373 }
374
375
eap_sim_response_start(struct eap_sm * sm,struct eap_sim_data * data,u8 id,enum eap_sim_id_req id_req)376 static struct wpabuf * eap_sim_response_start(struct eap_sm *sm,
377 struct eap_sim_data *data, u8 id,
378 enum eap_sim_id_req id_req)
379 {
380 const u8 *identity = NULL;
381 size_t identity_len = 0;
382 struct eap_sim_msg *msg;
383
384 data->reauth = 0;
385 if (id_req == ANY_ID && data->reauth_id) {
386 identity = data->reauth_id;
387 identity_len = data->reauth_id_len;
388 data->reauth = 1;
389 } else if ((id_req == ANY_ID || id_req == FULLAUTH_ID) &&
390 data->pseudonym) {
391 identity = data->pseudonym;
392 identity_len = data->pseudonym_len;
393 eap_sim_clear_identities(sm, data, CLEAR_REAUTH_ID);
394 } else if (id_req != NO_ID_REQ) {
395 identity = eap_get_config_identity(sm, &identity_len);
396 if (identity) {
397 eap_sim_clear_identities(sm, data, CLEAR_PSEUDONYM |
398 CLEAR_REAUTH_ID);
399 }
400 }
401 if (id_req != NO_ID_REQ)
402 eap_sim_clear_identities(sm, data, CLEAR_EAP_ID);
403
404 wpa_printf(MSG_DEBUG, "Generating EAP-SIM Start (id=%d)", id);
405 msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id,
406 EAP_TYPE_SIM, EAP_SIM_SUBTYPE_START);
407 if (!data->reauth) {
408 wpa_hexdump(MSG_DEBUG, " AT_NONCE_MT",
409 data->nonce_mt, EAP_SIM_NONCE_MT_LEN);
410 eap_sim_msg_add(msg, EAP_SIM_AT_NONCE_MT, 0,
411 data->nonce_mt, EAP_SIM_NONCE_MT_LEN);
412 wpa_printf(MSG_DEBUG, " AT_SELECTED_VERSION %d",
413 data->selected_version);
414 eap_sim_msg_add(msg, EAP_SIM_AT_SELECTED_VERSION,
415 data->selected_version, NULL, 0);
416 }
417
418 if (identity) {
419 wpa_hexdump_ascii(MSG_DEBUG, " AT_IDENTITY",
420 identity, identity_len);
421 eap_sim_msg_add(msg, EAP_SIM_AT_IDENTITY, identity_len,
422 identity, identity_len);
423 }
424
425 return eap_sim_msg_finish(msg, NULL, NULL, 0);
426 }
427
428
eap_sim_response_challenge(struct eap_sim_data * data,u8 id)429 static struct wpabuf * eap_sim_response_challenge(struct eap_sim_data *data,
430 u8 id)
431 {
432 struct eap_sim_msg *msg;
433
434 wpa_printf(MSG_DEBUG, "Generating EAP-SIM Challenge (id=%d)", id);
435 msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, EAP_TYPE_SIM,
436 EAP_SIM_SUBTYPE_CHALLENGE);
437 if (data->use_result_ind) {
438 wpa_printf(MSG_DEBUG, " AT_RESULT_IND");
439 eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0);
440 }
441 wpa_printf(MSG_DEBUG, " AT_MAC");
442 eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
443 return eap_sim_msg_finish(msg, data->k_aut, (u8 *) data->sres,
444 data->num_chal * EAP_SIM_SRES_LEN);
445 }
446
447
eap_sim_response_reauth(struct eap_sim_data * data,u8 id,int counter_too_small,const u8 * nonce_s)448 static struct wpabuf * eap_sim_response_reauth(struct eap_sim_data *data,
449 u8 id, int counter_too_small,
450 const u8 *nonce_s)
451 {
452 struct eap_sim_msg *msg;
453 unsigned int counter;
454
455 wpa_printf(MSG_DEBUG, "Generating EAP-SIM Reauthentication (id=%d)",
456 id);
457 msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, EAP_TYPE_SIM,
458 EAP_SIM_SUBTYPE_REAUTHENTICATION);
459 wpa_printf(MSG_DEBUG, " AT_IV");
460 wpa_printf(MSG_DEBUG, " AT_ENCR_DATA");
461 eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV, EAP_SIM_AT_ENCR_DATA);
462
463 if (counter_too_small) {
464 wpa_printf(MSG_DEBUG, " *AT_COUNTER_TOO_SMALL");
465 eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER_TOO_SMALL, 0, NULL, 0);
466 counter = data->counter_too_small;
467 } else
468 counter = data->counter;
469
470 wpa_printf(MSG_DEBUG, " *AT_COUNTER %d", counter);
471 eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, counter, NULL, 0);
472
473 if (eap_sim_msg_add_encr_end(msg, data->k_encr, EAP_SIM_AT_PADDING)) {
474 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to encrypt "
475 "AT_ENCR_DATA");
476 eap_sim_msg_free(msg);
477 return NULL;
478 }
479 if (data->use_result_ind) {
480 wpa_printf(MSG_DEBUG, " AT_RESULT_IND");
481 eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0);
482 }
483 wpa_printf(MSG_DEBUG, " AT_MAC");
484 eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
485 return eap_sim_msg_finish(msg, data->k_aut, nonce_s,
486 EAP_SIM_NONCE_S_LEN);
487 }
488
489
eap_sim_response_notification(struct eap_sim_data * data,u8 id,u16 notification)490 static struct wpabuf * eap_sim_response_notification(struct eap_sim_data *data,
491 u8 id, u16 notification)
492 {
493 struct eap_sim_msg *msg;
494 u8 *k_aut = (notification & 0x4000) == 0 ? data->k_aut : NULL;
495
496 wpa_printf(MSG_DEBUG, "Generating EAP-SIM Notification (id=%d)", id);
497 msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id,
498 EAP_TYPE_SIM, EAP_SIM_SUBTYPE_NOTIFICATION);
499 if (k_aut && data->reauth) {
500 wpa_printf(MSG_DEBUG, " AT_IV");
501 wpa_printf(MSG_DEBUG, " AT_ENCR_DATA");
502 eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV,
503 EAP_SIM_AT_ENCR_DATA);
504 wpa_printf(MSG_DEBUG, " *AT_COUNTER %d", data->counter);
505 eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, data->counter,
506 NULL, 0);
507 if (eap_sim_msg_add_encr_end(msg, data->k_encr,
508 EAP_SIM_AT_PADDING)) {
509 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to encrypt "
510 "AT_ENCR_DATA");
511 eap_sim_msg_free(msg);
512 return NULL;
513 }
514 }
515 if (k_aut) {
516 wpa_printf(MSG_DEBUG, " AT_MAC");
517 eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
518 }
519 return eap_sim_msg_finish(msg, k_aut, (u8 *) "", 0);
520 }
521
522
eap_sim_process_start(struct eap_sm * sm,struct eap_sim_data * data,u8 id,struct eap_sim_attrs * attr)523 static struct wpabuf * eap_sim_process_start(struct eap_sm *sm,
524 struct eap_sim_data *data, u8 id,
525 struct eap_sim_attrs *attr)
526 {
527 int selected_version = -1, id_error;
528 size_t i;
529 u8 *pos;
530
531 wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Start");
532 if (attr->version_list == NULL) {
533 wpa_printf(MSG_INFO, "EAP-SIM: No AT_VERSION_LIST in "
534 "SIM/Start");
535 return eap_sim_client_error(data, id,
536 EAP_SIM_UNSUPPORTED_VERSION);
537 }
538
539 os_free(data->ver_list);
540 data->ver_list = os_malloc(attr->version_list_len);
541 if (data->ver_list == NULL) {
542 wpa_printf(MSG_DEBUG, "EAP-SIM: Failed to allocate "
543 "memory for version list");
544 return eap_sim_client_error(data, id,
545 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
546 }
547 os_memcpy(data->ver_list, attr->version_list, attr->version_list_len);
548 data->ver_list_len = attr->version_list_len;
549 pos = data->ver_list;
550 for (i = 0; i < data->ver_list_len / 2; i++) {
551 int ver = pos[0] * 256 + pos[1];
552 pos += 2;
553 if (eap_sim_supported_ver(ver)) {
554 selected_version = ver;
555 break;
556 }
557 }
558 if (selected_version < 0) {
559 wpa_printf(MSG_INFO, "EAP-SIM: Could not find a supported "
560 "version");
561 return eap_sim_client_error(data, id,
562 EAP_SIM_UNSUPPORTED_VERSION);
563 }
564 wpa_printf(MSG_DEBUG, "EAP-SIM: Selected Version %d",
565 selected_version);
566 data->selected_version = selected_version;
567
568 id_error = 0;
569 switch (attr->id_req) {
570 case NO_ID_REQ:
571 break;
572 case ANY_ID:
573 if (data->num_id_req > 0)
574 id_error++;
575 data->num_id_req++;
576 break;
577 case FULLAUTH_ID:
578 if (data->num_id_req > 1)
579 id_error++;
580 data->num_id_req++;
581 break;
582 case PERMANENT_ID:
583 if (data->num_id_req > 2)
584 id_error++;
585 data->num_id_req++;
586 break;
587 }
588 if (id_error) {
589 wpa_printf(MSG_INFO, "EAP-SIM: Too many ID requests "
590 "used within one authentication");
591 return eap_sim_client_error(data, id,
592 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
593 }
594
595 return eap_sim_response_start(sm, data, id, attr->id_req);
596 }
597
598
eap_sim_process_challenge(struct eap_sm * sm,struct eap_sim_data * data,u8 id,const struct wpabuf * reqData,struct eap_sim_attrs * attr)599 static struct wpabuf * eap_sim_process_challenge(struct eap_sm *sm,
600 struct eap_sim_data *data,
601 u8 id,
602 const struct wpabuf *reqData,
603 struct eap_sim_attrs *attr)
604 {
605 const u8 *identity;
606 size_t identity_len;
607 struct eap_sim_attrs eattr;
608
609 wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Challenge");
610 data->reauth = 0;
611 if (!attr->mac || !attr->rand) {
612 wpa_printf(MSG_WARNING, "EAP-SIM: Challenge message "
613 "did not include%s%s",
614 !attr->mac ? " AT_MAC" : "",
615 !attr->rand ? " AT_RAND" : "");
616 return eap_sim_client_error(data, id,
617 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
618 }
619
620 wpa_printf(MSG_DEBUG, "EAP-SIM: %lu challenges",
621 (unsigned long) attr->num_chal);
622 if (attr->num_chal < data->min_num_chal) {
623 wpa_printf(MSG_INFO, "EAP-SIM: Insufficient number of "
624 "challenges (%lu)", (unsigned long) attr->num_chal);
625 return eap_sim_client_error(data, id,
626 EAP_SIM_INSUFFICIENT_NUM_OF_CHAL);
627 }
628 if (attr->num_chal > 3) {
629 wpa_printf(MSG_INFO, "EAP-SIM: Too many challenges "
630 "(%lu)", (unsigned long) attr->num_chal);
631 return eap_sim_client_error(data, id,
632 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
633 }
634
635 /* Verify that RANDs are different */
636 if (os_memcmp(attr->rand, attr->rand + GSM_RAND_LEN,
637 GSM_RAND_LEN) == 0 ||
638 (attr->num_chal > 2 &&
639 (os_memcmp(attr->rand, attr->rand + 2 * GSM_RAND_LEN,
640 GSM_RAND_LEN) == 0 ||
641 os_memcmp(attr->rand + GSM_RAND_LEN,
642 attr->rand + 2 * GSM_RAND_LEN,
643 GSM_RAND_LEN) == 0))) {
644 wpa_printf(MSG_INFO, "EAP-SIM: Same RAND used multiple times");
645 return eap_sim_client_error(data, id,
646 EAP_SIM_RAND_NOT_FRESH);
647 }
648
649 os_memcpy(data->rand, attr->rand, attr->num_chal * GSM_RAND_LEN);
650 data->num_chal = attr->num_chal;
651
652 if (eap_sim_gsm_auth(sm, data)) {
653 wpa_printf(MSG_WARNING, "EAP-SIM: GSM authentication failed");
654 return eap_sim_client_error(data, id,
655 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
656 }
657 if (data->last_eap_identity) {
658 identity = data->last_eap_identity;
659 identity_len = data->last_eap_identity_len;
660 } else if (data->pseudonym) {
661 identity = data->pseudonym;
662 identity_len = data->pseudonym_len;
663 } else
664 identity = eap_get_config_identity(sm, &identity_len);
665 wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Selected identity for MK "
666 "derivation", identity, identity_len);
667 eap_sim_derive_mk(identity, identity_len, data->nonce_mt,
668 data->selected_version, data->ver_list,
669 data->ver_list_len, data->num_chal,
670 (const u8 *) data->kc, data->mk);
671 eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut, data->msk,
672 data->emsk);
673 if (eap_sim_verify_mac(data->k_aut, reqData, attr->mac, data->nonce_mt,
674 EAP_SIM_NONCE_MT_LEN)) {
675 wpa_printf(MSG_WARNING, "EAP-SIM: Challenge message "
676 "used invalid AT_MAC");
677 return eap_sim_client_error(data, id,
678 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
679 }
680
681 /* Old reauthentication identity must not be used anymore. In
682 * other words, if no new reauth identity is received, full
683 * authentication will be used on next reauthentication (using
684 * pseudonym identity or permanent identity). */
685 eap_sim_clear_identities(sm, data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
686
687 if (attr->encr_data) {
688 u8 *decrypted;
689 decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
690 attr->encr_data_len, attr->iv,
691 &eattr, 0);
692 if (decrypted == NULL) {
693 return eap_sim_client_error(
694 data, id, EAP_SIM_UNABLE_TO_PROCESS_PACKET);
695 }
696 eap_sim_learn_ids(sm, data, &eattr);
697 os_free(decrypted);
698 }
699
700 if (data->result_ind && attr->result_ind)
701 data->use_result_ind = 1;
702
703 if (data->state != FAILURE && data->state != RESULT_FAILURE) {
704 eap_sim_state(data, data->use_result_ind ?
705 RESULT_SUCCESS : SUCCESS);
706 }
707
708 data->num_id_req = 0;
709 data->num_notification = 0;
710 /* RFC 4186 specifies that counter is initialized to one after
711 * fullauth, but initializing it to zero makes it easier to implement
712 * reauth verification. */
713 data->counter = 0;
714 return eap_sim_response_challenge(data, id);
715 }
716
717
eap_sim_process_notification_reauth(struct eap_sim_data * data,struct eap_sim_attrs * attr)718 static int eap_sim_process_notification_reauth(struct eap_sim_data *data,
719 struct eap_sim_attrs *attr)
720 {
721 struct eap_sim_attrs eattr;
722 u8 *decrypted;
723
724 if (attr->encr_data == NULL || attr->iv == NULL) {
725 wpa_printf(MSG_WARNING, "EAP-SIM: Notification message after "
726 "reauth did not include encrypted data");
727 return -1;
728 }
729
730 decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
731 attr->encr_data_len, attr->iv, &eattr,
732 0);
733 if (decrypted == NULL) {
734 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to parse encrypted "
735 "data from notification message");
736 return -1;
737 }
738
739 if (eattr.counter < 0 || (size_t) eattr.counter != data->counter) {
740 wpa_printf(MSG_WARNING, "EAP-SIM: Counter in notification "
741 "message does not match with counter in reauth "
742 "message");
743 os_free(decrypted);
744 return -1;
745 }
746
747 os_free(decrypted);
748 return 0;
749 }
750
751
eap_sim_process_notification_auth(struct eap_sim_data * data,const struct wpabuf * reqData,struct eap_sim_attrs * attr)752 static int eap_sim_process_notification_auth(struct eap_sim_data *data,
753 const struct wpabuf *reqData,
754 struct eap_sim_attrs *attr)
755 {
756 if (attr->mac == NULL) {
757 wpa_printf(MSG_INFO, "EAP-SIM: no AT_MAC in after_auth "
758 "Notification message");
759 return -1;
760 }
761
762 if (eap_sim_verify_mac(data->k_aut, reqData, attr->mac, (u8 *) "", 0))
763 {
764 wpa_printf(MSG_WARNING, "EAP-SIM: Notification message "
765 "used invalid AT_MAC");
766 return -1;
767 }
768
769 if (data->reauth &&
770 eap_sim_process_notification_reauth(data, attr)) {
771 wpa_printf(MSG_WARNING, "EAP-SIM: Invalid notification "
772 "message after reauth");
773 return -1;
774 }
775
776 return 0;
777 }
778
779
eap_sim_process_notification(struct eap_sm * sm,struct eap_sim_data * data,u8 id,const struct wpabuf * reqData,struct eap_sim_attrs * attr)780 static struct wpabuf * eap_sim_process_notification(
781 struct eap_sm *sm, struct eap_sim_data *data, u8 id,
782 const struct wpabuf *reqData, struct eap_sim_attrs *attr)
783 {
784 wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Notification");
785 if (data->num_notification > 0) {
786 wpa_printf(MSG_INFO, "EAP-SIM: too many notification "
787 "rounds (only one allowed)");
788 return eap_sim_client_error(data, id,
789 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
790 }
791 data->num_notification++;
792 if (attr->notification == -1) {
793 wpa_printf(MSG_INFO, "EAP-SIM: no AT_NOTIFICATION in "
794 "Notification message");
795 return eap_sim_client_error(data, id,
796 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
797 }
798
799 if ((attr->notification & 0x4000) == 0 &&
800 eap_sim_process_notification_auth(data, reqData, attr)) {
801 return eap_sim_client_error(data, id,
802 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
803 }
804
805 eap_sim_report_notification(sm->msg_ctx, attr->notification, 0);
806 if (attr->notification >= 0 && attr->notification < 32768) {
807 eap_sim_state(data, FAILURE);
808 } else if (attr->notification == EAP_SIM_SUCCESS &&
809 data->state == RESULT_SUCCESS)
810 eap_sim_state(data, SUCCESS);
811 return eap_sim_response_notification(data, id, attr->notification);
812 }
813
814
eap_sim_process_reauthentication(struct eap_sm * sm,struct eap_sim_data * data,u8 id,const struct wpabuf * reqData,struct eap_sim_attrs * attr)815 static struct wpabuf * eap_sim_process_reauthentication(
816 struct eap_sm *sm, struct eap_sim_data *data, u8 id,
817 const struct wpabuf *reqData, struct eap_sim_attrs *attr)
818 {
819 struct eap_sim_attrs eattr;
820 u8 *decrypted;
821
822 wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Reauthentication");
823
824 if (data->reauth_id == NULL) {
825 wpa_printf(MSG_WARNING, "EAP-SIM: Server is trying "
826 "reauthentication, but no reauth_id available");
827 return eap_sim_client_error(data, id,
828 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
829 }
830
831 data->reauth = 1;
832 if (eap_sim_verify_mac(data->k_aut, reqData, attr->mac, (u8 *) "", 0))
833 {
834 wpa_printf(MSG_WARNING, "EAP-SIM: Reauthentication "
835 "did not have valid AT_MAC");
836 return eap_sim_client_error(data, id,
837 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
838 }
839
840 if (attr->encr_data == NULL || attr->iv == NULL) {
841 wpa_printf(MSG_WARNING, "EAP-SIM: Reauthentication "
842 "message did not include encrypted data");
843 return eap_sim_client_error(data, id,
844 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
845 }
846
847 decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
848 attr->encr_data_len, attr->iv, &eattr,
849 0);
850 if (decrypted == NULL) {
851 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to parse encrypted "
852 "data from reauthentication message");
853 return eap_sim_client_error(data, id,
854 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
855 }
856
857 if (eattr.nonce_s == NULL || eattr.counter < 0) {
858 wpa_printf(MSG_INFO, "EAP-SIM: (encr) No%s%s in reauth packet",
859 !eattr.nonce_s ? " AT_NONCE_S" : "",
860 eattr.counter < 0 ? " AT_COUNTER" : "");
861 os_free(decrypted);
862 return eap_sim_client_error(data, id,
863 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
864 }
865
866 if (eattr.counter < 0 || (size_t) eattr.counter <= data->counter) {
867 wpa_printf(MSG_INFO, "EAP-SIM: (encr) Invalid counter "
868 "(%d <= %d)", eattr.counter, data->counter);
869 data->counter_too_small = eattr.counter;
870 /* Reply using Re-auth w/ AT_COUNTER_TOO_SMALL. The current
871 * reauth_id must not be used to start a new reauthentication.
872 * However, since it was used in the last EAP-Response-Identity
873 * packet, it has to saved for the following fullauth to be
874 * used in MK derivation. */
875 os_free(data->last_eap_identity);
876 data->last_eap_identity = data->reauth_id;
877 data->last_eap_identity_len = data->reauth_id_len;
878 data->reauth_id = NULL;
879 data->reauth_id_len = 0;
880 os_free(decrypted);
881 return eap_sim_response_reauth(data, id, 1, eattr.nonce_s);
882 }
883 data->counter = eattr.counter;
884
885 os_memcpy(data->nonce_s, eattr.nonce_s, EAP_SIM_NONCE_S_LEN);
886 wpa_hexdump(MSG_DEBUG, "EAP-SIM: (encr) AT_NONCE_S",
887 data->nonce_s, EAP_SIM_NONCE_S_LEN);
888
889 eap_sim_derive_keys_reauth(data->counter,
890 data->reauth_id, data->reauth_id_len,
891 data->nonce_s, data->mk, data->msk,
892 data->emsk);
893 eap_sim_clear_identities(sm, data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
894 eap_sim_learn_ids(sm, data, &eattr);
895
896 if (data->result_ind && attr->result_ind)
897 data->use_result_ind = 1;
898
899 if (data->state != FAILURE && data->state != RESULT_FAILURE) {
900 eap_sim_state(data, data->use_result_ind ?
901 RESULT_SUCCESS : SUCCESS);
902 }
903
904 data->num_id_req = 0;
905 data->num_notification = 0;
906 if (data->counter > EAP_SIM_MAX_FAST_REAUTHS) {
907 wpa_printf(MSG_DEBUG, "EAP-SIM: Maximum number of "
908 "fast reauths performed - force fullauth");
909 eap_sim_clear_identities(sm, data,
910 CLEAR_REAUTH_ID | CLEAR_EAP_ID);
911 }
912 os_free(decrypted);
913 return eap_sim_response_reauth(data, id, 0, data->nonce_s);
914 }
915
916
eap_sim_process(struct eap_sm * sm,void * priv,struct eap_method_ret * ret,const struct wpabuf * reqData)917 static struct wpabuf * eap_sim_process(struct eap_sm *sm, void *priv,
918 struct eap_method_ret *ret,
919 const struct wpabuf *reqData)
920 {
921 struct eap_sim_data *data = priv;
922 const struct eap_hdr *req;
923 u8 subtype, id;
924 struct wpabuf *res;
925 const u8 *pos;
926 struct eap_sim_attrs attr;
927 size_t len;
928
929 wpa_hexdump_buf(MSG_DEBUG, "EAP-SIM: EAP data", reqData);
930 if (eap_get_config_identity(sm, &len) == NULL) {
931 wpa_printf(MSG_INFO, "EAP-SIM: Identity not configured");
932 eap_sm_request_identity(sm);
933 ret->ignore = TRUE;
934 return NULL;
935 }
936
937 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SIM, reqData, &len);
938 if (pos == NULL || len < 1) {
939 ret->ignore = TRUE;
940 return NULL;
941 }
942 req = wpabuf_head(reqData);
943 id = req->identifier;
944 len = be_to_host16(req->length);
945
946 ret->ignore = FALSE;
947 ret->methodState = METHOD_MAY_CONT;
948 ret->decision = DECISION_FAIL;
949 ret->allowNotifications = TRUE;
950
951 subtype = *pos++;
952 wpa_printf(MSG_DEBUG, "EAP-SIM: Subtype=%d", subtype);
953 pos += 2; /* Reserved */
954
955 if (eap_sim_parse_attr(pos, wpabuf_head_u8(reqData) + len, &attr, 0,
956 0)) {
957 res = eap_sim_client_error(data, id,
958 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
959 goto done;
960 }
961
962 switch (subtype) {
963 case EAP_SIM_SUBTYPE_START:
964 res = eap_sim_process_start(sm, data, id, &attr);
965 break;
966 case EAP_SIM_SUBTYPE_CHALLENGE:
967 res = eap_sim_process_challenge(sm, data, id, reqData, &attr);
968 break;
969 case EAP_SIM_SUBTYPE_NOTIFICATION:
970 res = eap_sim_process_notification(sm, data, id, reqData,
971 &attr);
972 break;
973 case EAP_SIM_SUBTYPE_REAUTHENTICATION:
974 res = eap_sim_process_reauthentication(sm, data, id, reqData,
975 &attr);
976 break;
977 case EAP_SIM_SUBTYPE_CLIENT_ERROR:
978 wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Client-Error");
979 res = eap_sim_client_error(data, id,
980 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
981 break;
982 default:
983 wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown subtype=%d", subtype);
984 res = eap_sim_client_error(data, id,
985 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
986 break;
987 }
988
989 done:
990 if (data->state == FAILURE) {
991 ret->decision = DECISION_FAIL;
992 ret->methodState = METHOD_DONE;
993 } else if (data->state == SUCCESS) {
994 ret->decision = data->use_result_ind ?
995 DECISION_UNCOND_SUCC : DECISION_COND_SUCC;
996 ret->methodState = data->use_result_ind ?
997 METHOD_DONE : METHOD_MAY_CONT;
998 } else if (data->state == RESULT_FAILURE)
999 ret->methodState = METHOD_CONT;
1000 else if (data->state == RESULT_SUCCESS)
1001 ret->methodState = METHOD_CONT;
1002
1003 if (ret->methodState == METHOD_DONE) {
1004 ret->allowNotifications = FALSE;
1005 }
1006
1007 return res;
1008 }
1009
1010
eap_sim_has_reauth_data(struct eap_sm * sm,void * priv)1011 static Boolean eap_sim_has_reauth_data(struct eap_sm *sm, void *priv)
1012 {
1013 struct eap_sim_data *data = priv;
1014 return data->pseudonym || data->reauth_id;
1015 }
1016
1017
eap_sim_deinit_for_reauth(struct eap_sm * sm,void * priv)1018 static void eap_sim_deinit_for_reauth(struct eap_sm *sm, void *priv)
1019 {
1020 struct eap_sim_data *data = priv;
1021 eap_sim_clear_identities(sm, data, CLEAR_EAP_ID);
1022 data->use_result_ind = 0;
1023 }
1024
1025
eap_sim_init_for_reauth(struct eap_sm * sm,void * priv)1026 static void * eap_sim_init_for_reauth(struct eap_sm *sm, void *priv)
1027 {
1028 struct eap_sim_data *data = priv;
1029 if (random_get_bytes(data->nonce_mt, EAP_SIM_NONCE_MT_LEN)) {
1030 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to get random data "
1031 "for NONCE_MT");
1032 os_free(data);
1033 return NULL;
1034 }
1035 data->num_id_req = 0;
1036 data->num_notification = 0;
1037 eap_sim_state(data, CONTINUE);
1038 return priv;
1039 }
1040
1041
eap_sim_get_identity(struct eap_sm * sm,void * priv,size_t * len)1042 static const u8 * eap_sim_get_identity(struct eap_sm *sm, void *priv,
1043 size_t *len)
1044 {
1045 struct eap_sim_data *data = priv;
1046
1047 if (data->reauth_id) {
1048 *len = data->reauth_id_len;
1049 return data->reauth_id;
1050 }
1051
1052 if (data->pseudonym) {
1053 *len = data->pseudonym_len;
1054 return data->pseudonym;
1055 }
1056
1057 return NULL;
1058 }
1059
1060
eap_sim_isKeyAvailable(struct eap_sm * sm,void * priv)1061 static Boolean eap_sim_isKeyAvailable(struct eap_sm *sm, void *priv)
1062 {
1063 struct eap_sim_data *data = priv;
1064 return data->state == SUCCESS;
1065 }
1066
1067
eap_sim_getKey(struct eap_sm * sm,void * priv,size_t * len)1068 static u8 * eap_sim_getKey(struct eap_sm *sm, void *priv, size_t *len)
1069 {
1070 struct eap_sim_data *data = priv;
1071 u8 *key;
1072
1073 if (data->state != SUCCESS)
1074 return NULL;
1075
1076 key = os_malloc(EAP_SIM_KEYING_DATA_LEN);
1077 if (key == NULL)
1078 return NULL;
1079
1080 *len = EAP_SIM_KEYING_DATA_LEN;
1081 os_memcpy(key, data->msk, EAP_SIM_KEYING_DATA_LEN);
1082
1083 return key;
1084 }
1085
1086
eap_sim_get_emsk(struct eap_sm * sm,void * priv,size_t * len)1087 static u8 * eap_sim_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
1088 {
1089 struct eap_sim_data *data = priv;
1090 u8 *key;
1091
1092 if (data->state != SUCCESS)
1093 return NULL;
1094
1095 key = os_malloc(EAP_EMSK_LEN);
1096 if (key == NULL)
1097 return NULL;
1098
1099 *len = EAP_EMSK_LEN;
1100 os_memcpy(key, data->emsk, EAP_EMSK_LEN);
1101
1102 return key;
1103 }
1104
1105
eap_peer_sim_register(void)1106 int eap_peer_sim_register(void)
1107 {
1108 struct eap_method *eap;
1109 int ret;
1110
1111 eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
1112 EAP_VENDOR_IETF, EAP_TYPE_SIM, "SIM");
1113 if (eap == NULL)
1114 return -1;
1115
1116 eap->init = eap_sim_init;
1117 eap->deinit = eap_sim_deinit;
1118 eap->process = eap_sim_process;
1119 eap->isKeyAvailable = eap_sim_isKeyAvailable;
1120 eap->getKey = eap_sim_getKey;
1121 eap->has_reauth_data = eap_sim_has_reauth_data;
1122 eap->deinit_for_reauth = eap_sim_deinit_for_reauth;
1123 eap->init_for_reauth = eap_sim_init_for_reauth;
1124 eap->get_identity = eap_sim_get_identity;
1125 eap->get_emsk = eap_sim_get_emsk;
1126
1127 ret = eap_peer_method_register(eap);
1128 if (ret)
1129 eap_peer_method_free(eap);
1130 return ret;
1131 }
1132