1 /*
2 * EAP peer method: EAP-SIM (RFC 4186)
3 * Copyright (c) 2004-2006, Jouni Malinen <j@w1.fi>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * Alternatively, this software may be distributed under the terms of BSD
10 * license.
11 *
12 * See README and COPYING for more details.
13 */
14
15 #include "includes.h"
16
17 #include "common.h"
18 #include "eap_i.h"
19 #include "config_ssid.h"
20 #include "crypto.h"
21 #include "pcsc_funcs.h"
22 #include "eap_sim_common.h"
23
24
25 struct eap_sim_data {
26 u8 *ver_list;
27 size_t ver_list_len;
28 int selected_version;
29 size_t min_num_chal, num_chal;
30
31 u8 kc[3][EAP_SIM_KC_LEN];
32 u8 sres[3][EAP_SIM_SRES_LEN];
33 u8 nonce_mt[EAP_SIM_NONCE_MT_LEN], nonce_s[EAP_SIM_NONCE_S_LEN];
34 u8 mk[EAP_SIM_MK_LEN];
35 u8 k_aut[EAP_SIM_K_AUT_LEN];
36 u8 k_encr[EAP_SIM_K_ENCR_LEN];
37 u8 msk[EAP_SIM_KEYING_DATA_LEN];
38 u8 emsk[EAP_EMSK_LEN];
39 u8 rand[3][GSM_RAND_LEN];
40
41 int num_id_req, num_notification;
42 u8 *pseudonym;
43 size_t pseudonym_len;
44 u8 *reauth_id;
45 size_t reauth_id_len;
46 int reauth;
47 unsigned int counter, counter_too_small;
48 u8 *last_eap_identity;
49 size_t last_eap_identity_len;
50 enum { CONTINUE, SUCCESS, FAILURE } state;
51 };
52
53
eap_sim_init(struct eap_sm * sm)54 static void * eap_sim_init(struct eap_sm *sm)
55 {
56 struct eap_sim_data *data;
57 struct wpa_ssid *config = eap_get_config(sm);
58
59 data = os_zalloc(sizeof(*data));
60 if (data == NULL)
61 return NULL;
62
63 if (hostapd_get_rand(data->nonce_mt, EAP_SIM_NONCE_MT_LEN)) {
64 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to get random data "
65 "for NONCE_MT");
66 os_free(data);
67 return NULL;
68 }
69
70 data->min_num_chal = 2;
71 if (config && config->phase1) {
72 char *pos = os_strstr(config->phase1, "sim_min_num_chal=");
73 if (pos) {
74 data->min_num_chal = atoi(pos + 17);
75 if (data->min_num_chal < 2 || data->min_num_chal > 3) {
76 wpa_printf(MSG_WARNING, "EAP-SIM: Invalid "
77 "sim_min_num_chal configuration "
78 "(%lu, expected 2 or 3)",
79 (unsigned long) data->min_num_chal);
80 os_free(data);
81 return NULL;
82 }
83 wpa_printf(MSG_DEBUG, "EAP-SIM: Set minimum number of "
84 "challenges to %lu",
85 (unsigned long) data->min_num_chal);
86 }
87 }
88
89 data->state = CONTINUE;
90
91 return data;
92 }
93
94
eap_sim_deinit(struct eap_sm * sm,void * priv)95 static void eap_sim_deinit(struct eap_sm *sm, void *priv)
96 {
97 struct eap_sim_data *data = priv;
98 if (data) {
99 os_free(data->ver_list);
100 os_free(data->pseudonym);
101 os_free(data->reauth_id);
102 os_free(data->last_eap_identity);
103 os_free(data);
104 }
105 }
106
107
eap_sim_gsm_auth(struct eap_sm * sm,struct eap_sim_data * data)108 static int eap_sim_gsm_auth(struct eap_sm *sm, struct eap_sim_data *data)
109 {
110 wpa_printf(MSG_DEBUG, "EAP-SIM: GSM authentication algorithm");
111 #ifdef PCSC_FUNCS
112 if (scard_gsm_auth(sm->scard_ctx, data->rand[0],
113 data->sres[0], data->kc[0]) ||
114 scard_gsm_auth(sm->scard_ctx, data->rand[1],
115 data->sres[1], data->kc[1]) ||
116 (data->num_chal > 2 &&
117 scard_gsm_auth(sm->scard_ctx, data->rand[2],
118 data->sres[2], data->kc[2]))) {
119 wpa_printf(MSG_DEBUG, "EAP-SIM: GSM SIM authentication could "
120 "not be completed");
121 return -1;
122 }
123 #else /* PCSC_FUNCS */
124 /* These hardcoded Kc and SRES values are used for testing. RAND to
125 * KC/SREC mapping is very bogus as far as real authentication is
126 * concerned, but it is quite useful for cases where the AS is rotating
127 * the order of pre-configured values. */
128 {
129 size_t i;
130 for (i = 0; i < data->num_chal; i++) {
131 if (data->rand[i][0] == 0xaa) {
132 os_memcpy(data->kc[i],
133 "\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7",
134 EAP_SIM_KC_LEN);
135 os_memcpy(data->sres[i], "\xd1\xd2\xd3\xd4",
136 EAP_SIM_SRES_LEN);
137 } else if (data->rand[i][0] == 0xbb) {
138 os_memcpy(data->kc[i],
139 "\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7",
140 EAP_SIM_KC_LEN);
141 os_memcpy(data->sres[i], "\xe1\xe2\xe3\xe4",
142 EAP_SIM_SRES_LEN);
143 } else {
144 os_memcpy(data->kc[i],
145 "\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7",
146 EAP_SIM_KC_LEN);
147 os_memcpy(data->sres[i], "\xf1\xf2\xf3\xf4",
148 EAP_SIM_SRES_LEN);
149 }
150 }
151 }
152 #endif /* PCSC_FUNCS */
153 return 0;
154 }
155
156
eap_sim_supported_ver(int version)157 static int eap_sim_supported_ver(int version)
158 {
159 return version == EAP_SIM_VERSION;
160 }
161
162
163 #define CLEAR_PSEUDONYM 0x01
164 #define CLEAR_REAUTH_ID 0x02
165 #define CLEAR_EAP_ID 0x04
166
eap_sim_clear_identities(struct eap_sim_data * data,int id)167 static void eap_sim_clear_identities(struct eap_sim_data *data, int id)
168 {
169 wpa_printf(MSG_DEBUG, "EAP-SIM: forgetting old%s%s%s",
170 id & CLEAR_PSEUDONYM ? " pseudonym" : "",
171 id & CLEAR_REAUTH_ID ? " reauth_id" : "",
172 id & CLEAR_EAP_ID ? " eap_id" : "");
173 if (id & CLEAR_PSEUDONYM) {
174 os_free(data->pseudonym);
175 data->pseudonym = NULL;
176 data->pseudonym_len = 0;
177 }
178 if (id & CLEAR_REAUTH_ID) {
179 os_free(data->reauth_id);
180 data->reauth_id = NULL;
181 data->reauth_id_len = 0;
182 }
183 if (id & CLEAR_EAP_ID) {
184 os_free(data->last_eap_identity);
185 data->last_eap_identity = NULL;
186 data->last_eap_identity_len = 0;
187 }
188 }
189
190
eap_sim_learn_ids(struct eap_sim_data * data,struct eap_sim_attrs * attr)191 static int eap_sim_learn_ids(struct eap_sim_data *data,
192 struct eap_sim_attrs *attr)
193 {
194 if (attr->next_pseudonym) {
195 os_free(data->pseudonym);
196 data->pseudonym = os_malloc(attr->next_pseudonym_len);
197 if (data->pseudonym == NULL) {
198 wpa_printf(MSG_INFO, "EAP-SIM: (encr) No memory for "
199 "next pseudonym");
200 return -1;
201 }
202 os_memcpy(data->pseudonym, attr->next_pseudonym,
203 attr->next_pseudonym_len);
204 data->pseudonym_len = attr->next_pseudonym_len;
205 wpa_hexdump_ascii(MSG_DEBUG,
206 "EAP-SIM: (encr) AT_NEXT_PSEUDONYM",
207 data->pseudonym,
208 data->pseudonym_len);
209 }
210
211 if (attr->next_reauth_id) {
212 os_free(data->reauth_id);
213 data->reauth_id = os_malloc(attr->next_reauth_id_len);
214 if (data->reauth_id == NULL) {
215 wpa_printf(MSG_INFO, "EAP-SIM: (encr) No memory for "
216 "next reauth_id");
217 return -1;
218 }
219 os_memcpy(data->reauth_id, attr->next_reauth_id,
220 attr->next_reauth_id_len);
221 data->reauth_id_len = attr->next_reauth_id_len;
222 wpa_hexdump_ascii(MSG_DEBUG,
223 "EAP-SIM: (encr) AT_NEXT_REAUTH_ID",
224 data->reauth_id,
225 data->reauth_id_len);
226 }
227
228 return 0;
229 }
230
231
eap_sim_client_error(struct eap_sim_data * data,const struct eap_hdr * req,size_t * respDataLen,int err)232 static u8 * eap_sim_client_error(struct eap_sim_data *data,
233 const struct eap_hdr *req,
234 size_t *respDataLen, int err)
235 {
236 struct eap_sim_msg *msg;
237
238 data->state = FAILURE;
239 data->num_id_req = 0;
240 data->num_notification = 0;
241
242 msg = eap_sim_msg_init(EAP_CODE_RESPONSE, req->identifier,
243 EAP_TYPE_SIM, EAP_SIM_SUBTYPE_CLIENT_ERROR);
244 eap_sim_msg_add(msg, EAP_SIM_AT_CLIENT_ERROR_CODE, err, NULL, 0);
245 return eap_sim_msg_finish(msg, respDataLen, NULL, NULL, 0);
246 }
247
248
eap_sim_response_start(struct eap_sm * sm,struct eap_sim_data * data,const struct eap_hdr * req,size_t * respDataLen,enum eap_sim_id_req id_req)249 static u8 * eap_sim_response_start(struct eap_sm *sm,
250 struct eap_sim_data *data,
251 const struct eap_hdr *req,
252 size_t *respDataLen,
253 enum eap_sim_id_req id_req)
254 {
255 const u8 *identity = NULL;
256 size_t identity_len = 0;
257 struct eap_sim_msg *msg;
258
259 data->reauth = 0;
260 if (id_req == ANY_ID && data->reauth_id) {
261 identity = data->reauth_id;
262 identity_len = data->reauth_id_len;
263 data->reauth = 1;
264 } else if ((id_req == ANY_ID || id_req == FULLAUTH_ID) &&
265 data->pseudonym) {
266 identity = data->pseudonym;
267 identity_len = data->pseudonym_len;
268 eap_sim_clear_identities(data, CLEAR_REAUTH_ID);
269 } else if (id_req != NO_ID_REQ) {
270 identity = eap_get_config_identity(sm, &identity_len);
271 if (identity) {
272 eap_sim_clear_identities(data, CLEAR_PSEUDONYM |
273 CLEAR_REAUTH_ID);
274 }
275 }
276 if (id_req != NO_ID_REQ)
277 eap_sim_clear_identities(data, CLEAR_EAP_ID);
278
279 wpa_printf(MSG_DEBUG, "Generating EAP-SIM Start (id=%d)",
280 req->identifier);
281 msg = eap_sim_msg_init(EAP_CODE_RESPONSE, req->identifier,
282 EAP_TYPE_SIM, EAP_SIM_SUBTYPE_START);
283 if (!data->reauth) {
284 wpa_hexdump(MSG_DEBUG, " AT_NONCE_MT",
285 data->nonce_mt, EAP_SIM_NONCE_MT_LEN);
286 eap_sim_msg_add(msg, EAP_SIM_AT_NONCE_MT, 0,
287 data->nonce_mt, EAP_SIM_NONCE_MT_LEN);
288 wpa_printf(MSG_DEBUG, " AT_SELECTED_VERSION %d",
289 data->selected_version);
290 eap_sim_msg_add(msg, EAP_SIM_AT_SELECTED_VERSION,
291 data->selected_version, NULL, 0);
292 }
293
294 if (identity) {
295 wpa_hexdump_ascii(MSG_DEBUG, " AT_IDENTITY",
296 identity, identity_len);
297 eap_sim_msg_add(msg, EAP_SIM_AT_IDENTITY, identity_len,
298 identity, identity_len);
299 }
300
301 return eap_sim_msg_finish(msg, respDataLen, NULL, NULL, 0);
302 }
303
304
eap_sim_response_challenge(struct eap_sim_data * data,const struct eap_hdr * req,size_t * respDataLen)305 static u8 * eap_sim_response_challenge(struct eap_sim_data *data,
306 const struct eap_hdr *req,
307 size_t *respDataLen)
308 {
309 struct eap_sim_msg *msg;
310
311 wpa_printf(MSG_DEBUG, "Generating EAP-SIM Challenge (id=%d)",
312 req->identifier);
313 msg = eap_sim_msg_init(EAP_CODE_RESPONSE, req->identifier,
314 EAP_TYPE_SIM, EAP_SIM_SUBTYPE_CHALLENGE);
315 wpa_printf(MSG_DEBUG, " AT_MAC");
316 eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
317 return eap_sim_msg_finish(msg, respDataLen, data->k_aut,
318 (u8 *) data->sres,
319 data->num_chal * EAP_SIM_SRES_LEN);
320 }
321
322
eap_sim_response_reauth(struct eap_sim_data * data,const struct eap_hdr * req,size_t * respDataLen,int counter_too_small)323 static u8 * eap_sim_response_reauth(struct eap_sim_data *data,
324 const struct eap_hdr *req,
325 size_t *respDataLen, int counter_too_small)
326 {
327 struct eap_sim_msg *msg;
328 unsigned int counter;
329
330 wpa_printf(MSG_DEBUG, "Generating EAP-SIM Reauthentication (id=%d)",
331 req->identifier);
332 msg = eap_sim_msg_init(EAP_CODE_RESPONSE, req->identifier,
333 EAP_TYPE_SIM,
334 EAP_SIM_SUBTYPE_REAUTHENTICATION);
335 wpa_printf(MSG_DEBUG, " AT_IV");
336 wpa_printf(MSG_DEBUG, " AT_ENCR_DATA");
337 eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV, EAP_SIM_AT_ENCR_DATA);
338
339 if (counter_too_small) {
340 wpa_printf(MSG_DEBUG, " *AT_COUNTER_TOO_SMALL");
341 eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER_TOO_SMALL, 0, NULL, 0);
342 counter = data->counter_too_small;
343 } else
344 counter = data->counter;
345
346 wpa_printf(MSG_DEBUG, " *AT_COUNTER %d", counter);
347 eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, counter, NULL, 0);
348
349 if (eap_sim_msg_add_encr_end(msg, data->k_encr, EAP_SIM_AT_PADDING)) {
350 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to encrypt "
351 "AT_ENCR_DATA");
352 eap_sim_msg_free(msg);
353 return NULL;
354 }
355 wpa_printf(MSG_DEBUG, " AT_MAC");
356 eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
357 return eap_sim_msg_finish(msg, respDataLen, data->k_aut, data->nonce_s,
358 EAP_SIM_NONCE_S_LEN);
359 }
360
361
eap_sim_response_notification(struct eap_sim_data * data,const struct eap_hdr * req,size_t * respDataLen,u16 notification)362 static u8 * eap_sim_response_notification(struct eap_sim_data *data,
363 const struct eap_hdr *req,
364 size_t *respDataLen,
365 u16 notification)
366 {
367 struct eap_sim_msg *msg;
368 u8 *k_aut = (notification & 0x4000) == 0 ? data->k_aut : NULL;
369
370 wpa_printf(MSG_DEBUG, "Generating EAP-SIM Notification (id=%d)",
371 req->identifier);
372 msg = eap_sim_msg_init(EAP_CODE_RESPONSE, req->identifier,
373 EAP_TYPE_SIM, EAP_SIM_SUBTYPE_NOTIFICATION);
374 wpa_printf(MSG_DEBUG, " AT_NOTIFICATION");
375 eap_sim_msg_add(msg, EAP_SIM_AT_NOTIFICATION, notification, NULL, 0);
376 if (k_aut && data->reauth) {
377 wpa_printf(MSG_DEBUG, " AT_IV");
378 wpa_printf(MSG_DEBUG, " AT_ENCR_DATA");
379 eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV,
380 EAP_SIM_AT_ENCR_DATA);
381 wpa_printf(MSG_DEBUG, " *AT_COUNTER %d", data->counter);
382 eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, data->counter,
383 NULL, 0);
384 if (eap_sim_msg_add_encr_end(msg, data->k_encr,
385 EAP_SIM_AT_PADDING)) {
386 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to encrypt "
387 "AT_ENCR_DATA");
388 eap_sim_msg_free(msg);
389 return NULL;
390 }
391 }
392 if (k_aut) {
393 wpa_printf(MSG_DEBUG, " AT_MAC");
394 eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
395 }
396 return eap_sim_msg_finish(msg, respDataLen, k_aut, (u8 *) "", 0);
397 }
398
399
eap_sim_process_start(struct eap_sm * sm,struct eap_sim_data * data,const struct eap_hdr * req,size_t * respDataLen,struct eap_sim_attrs * attr)400 static u8 * eap_sim_process_start(struct eap_sm *sm, struct eap_sim_data *data,
401 const struct eap_hdr *req,
402 size_t *respDataLen,
403 struct eap_sim_attrs *attr)
404 {
405 int selected_version = -1, id_error;
406 size_t i;
407 u8 *pos;
408
409 wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Start");
410 if (attr->version_list == NULL) {
411 wpa_printf(MSG_INFO, "EAP-SIM: No AT_VERSION_LIST in "
412 "SIM/Start");
413 return eap_sim_client_error(data, req, respDataLen,
414 EAP_SIM_UNSUPPORTED_VERSION);
415 }
416
417 os_free(data->ver_list);
418 data->ver_list = os_malloc(attr->version_list_len);
419 if (data->ver_list == NULL) {
420 wpa_printf(MSG_DEBUG, "EAP-SIM: Failed to allocate "
421 "memory for version list");
422 return eap_sim_client_error(data, req, respDataLen,
423 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
424 }
425 os_memcpy(data->ver_list, attr->version_list, attr->version_list_len);
426 data->ver_list_len = attr->version_list_len;
427 pos = data->ver_list;
428 for (i = 0; i < data->ver_list_len / 2; i++) {
429 int ver = pos[0] * 256 + pos[1];
430 pos += 2;
431 if (eap_sim_supported_ver(ver)) {
432 selected_version = ver;
433 break;
434 }
435 }
436 if (selected_version < 0) {
437 wpa_printf(MSG_INFO, "EAP-SIM: Could not find a supported "
438 "version");
439 return eap_sim_client_error(data, req, respDataLen,
440 EAP_SIM_UNSUPPORTED_VERSION);
441 }
442 wpa_printf(MSG_DEBUG, "EAP-SIM: Selected Version %d",
443 selected_version);
444 data->selected_version = selected_version;
445
446 id_error = 0;
447 switch (attr->id_req) {
448 case NO_ID_REQ:
449 break;
450 case ANY_ID:
451 if (data->num_id_req > 0)
452 id_error++;
453 data->num_id_req++;
454 break;
455 case FULLAUTH_ID:
456 if (data->num_id_req > 1)
457 id_error++;
458 data->num_id_req++;
459 break;
460 case PERMANENT_ID:
461 if (data->num_id_req > 2)
462 id_error++;
463 data->num_id_req++;
464 break;
465 }
466 if (id_error) {
467 wpa_printf(MSG_INFO, "EAP-SIM: Too many ID requests "
468 "used within one authentication");
469 return eap_sim_client_error(data, req, respDataLen,
470 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
471 }
472
473 return eap_sim_response_start(sm, data, req, respDataLen,
474 attr->id_req);
475 }
476
477
eap_sim_process_challenge(struct eap_sm * sm,struct eap_sim_data * data,const struct eap_hdr * req,size_t reqDataLen,size_t * respDataLen,struct eap_sim_attrs * attr)478 static u8 * eap_sim_process_challenge(struct eap_sm *sm,
479 struct eap_sim_data *data,
480 const struct eap_hdr *req,
481 size_t reqDataLen,
482 size_t *respDataLen,
483 struct eap_sim_attrs *attr)
484 {
485 const u8 *identity;
486 size_t identity_len;
487 struct eap_sim_attrs eattr;
488
489 wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Challenge");
490 data->reauth = 0;
491 if (!attr->mac || !attr->rand) {
492 wpa_printf(MSG_WARNING, "EAP-SIM: Challenge message "
493 "did not include%s%s",
494 !attr->mac ? " AT_MAC" : "",
495 !attr->rand ? " AT_RAND" : "");
496 return eap_sim_client_error(data, req, respDataLen,
497 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
498 }
499
500 wpa_printf(MSG_DEBUG, "EAP-SIM: %lu challenges",
501 (unsigned long) attr->num_chal);
502 if (attr->num_chal < data->min_num_chal) {
503 wpa_printf(MSG_INFO, "EAP-SIM: Insufficient number of "
504 "challenges (%lu)", (unsigned long) attr->num_chal);
505 return eap_sim_client_error(data, req, respDataLen,
506 EAP_SIM_INSUFFICIENT_NUM_OF_CHAL);
507 }
508 if (attr->num_chal > 3) {
509 wpa_printf(MSG_INFO, "EAP-SIM: Too many challenges "
510 "(%lu)", (unsigned long) attr->num_chal);
511 return eap_sim_client_error(data, req, respDataLen,
512 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
513 }
514
515 /* Verify that RANDs are different */
516 if (os_memcmp(attr->rand, attr->rand + GSM_RAND_LEN,
517 GSM_RAND_LEN) == 0 ||
518 (attr->num_chal > 2 &&
519 (os_memcmp(attr->rand, attr->rand + 2 * GSM_RAND_LEN,
520 GSM_RAND_LEN) == 0 ||
521 os_memcmp(attr->rand + GSM_RAND_LEN,
522 attr->rand + 2 * GSM_RAND_LEN,
523 GSM_RAND_LEN) == 0))) {
524 wpa_printf(MSG_INFO, "EAP-SIM: Same RAND used multiple times");
525 return eap_sim_client_error(data, req, respDataLen,
526 EAP_SIM_RAND_NOT_FRESH);
527 }
528
529 os_memcpy(data->rand, attr->rand, attr->num_chal * GSM_RAND_LEN);
530 data->num_chal = attr->num_chal;
531
532 if (eap_sim_gsm_auth(sm, data)) {
533 wpa_printf(MSG_WARNING, "EAP-SIM: GSM authentication failed");
534 return eap_sim_client_error(data, req, respDataLen,
535 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
536 }
537 if (data->last_eap_identity) {
538 identity = data->last_eap_identity;
539 identity_len = data->last_eap_identity_len;
540 } else if (data->pseudonym) {
541 identity = data->pseudonym;
542 identity_len = data->pseudonym_len;
543 } else
544 identity = eap_get_config_identity(sm, &identity_len);
545 wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Selected identity for MK "
546 "derivation", identity, identity_len);
547 eap_sim_derive_mk(identity, identity_len, data->nonce_mt,
548 data->selected_version, data->ver_list,
549 data->ver_list_len, data->num_chal,
550 (const u8 *) data->kc, data->mk);
551 eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut, data->msk,
552 data->emsk);
553 if (eap_sim_verify_mac(data->k_aut, (const u8 *) req, reqDataLen,
554 attr->mac, data->nonce_mt,
555 EAP_SIM_NONCE_MT_LEN)) {
556 wpa_printf(MSG_WARNING, "EAP-SIM: Challenge message "
557 "used invalid AT_MAC");
558 return eap_sim_client_error(data, req, respDataLen,
559 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
560 }
561
562 /* Old reauthentication and pseudonym identities must not be used
563 * anymore. In other words, if no new identities are received, full
564 * authentication will be used on next reauthentication. */
565 eap_sim_clear_identities(data, CLEAR_PSEUDONYM | CLEAR_REAUTH_ID |
566 CLEAR_EAP_ID);
567
568 if (attr->encr_data) {
569 u8 *decrypted;
570 decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
571 attr->encr_data_len, attr->iv,
572 &eattr, 0);
573 if (decrypted == NULL) {
574 return eap_sim_client_error(
575 data, req, respDataLen,
576 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
577 }
578 eap_sim_learn_ids(data, &eattr);
579 os_free(decrypted);
580 }
581
582 if (data->state != FAILURE)
583 data->state = SUCCESS;
584
585 data->num_id_req = 0;
586 data->num_notification = 0;
587 /* RFC 4186 specifies that counter is initialized to one after
588 * fullauth, but initializing it to zero makes it easier to implement
589 * reauth verification. */
590 data->counter = 0;
591 return eap_sim_response_challenge(data, req, respDataLen);
592 }
593
594
eap_sim_process_notification_reauth(struct eap_sim_data * data,struct eap_sim_attrs * attr)595 static int eap_sim_process_notification_reauth(struct eap_sim_data *data,
596 struct eap_sim_attrs *attr)
597 {
598 struct eap_sim_attrs eattr;
599 u8 *decrypted;
600
601 if (attr->encr_data == NULL || attr->iv == NULL) {
602 wpa_printf(MSG_WARNING, "EAP-SIM: Notification message after "
603 "reauth did not include encrypted data");
604 return -1;
605 }
606
607 decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
608 attr->encr_data_len, attr->iv, &eattr,
609 0);
610 if (decrypted == NULL) {
611 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to parse encrypted "
612 "data from notification message");
613 return -1;
614 }
615
616 if (eattr.counter < 0 || (size_t) eattr.counter != data->counter) {
617 wpa_printf(MSG_WARNING, "EAP-SIM: Counter in notification "
618 "message does not match with counter in reauth "
619 "message");
620 os_free(decrypted);
621 return -1;
622 }
623
624 os_free(decrypted);
625 return 0;
626 }
627
628
eap_sim_process_notification_auth(struct eap_sim_data * data,const struct eap_hdr * req,size_t reqDataLen,struct eap_sim_attrs * attr)629 static int eap_sim_process_notification_auth(struct eap_sim_data *data,
630 const struct eap_hdr *req,
631 size_t reqDataLen,
632 struct eap_sim_attrs *attr)
633 {
634 if (attr->mac == NULL) {
635 wpa_printf(MSG_INFO, "EAP-SIM: no AT_MAC in after_auth "
636 "Notification message");
637 return -1;
638 }
639
640 if (eap_sim_verify_mac(data->k_aut, (u8 *) req, reqDataLen, attr->mac,
641 (u8 *) "", 0)) {
642 wpa_printf(MSG_WARNING, "EAP-SIM: Notification message "
643 "used invalid AT_MAC");
644 return -1;
645 }
646
647 if (data->reauth &&
648 eap_sim_process_notification_reauth(data, attr)) {
649 wpa_printf(MSG_WARNING, "EAP-SIM: Invalid notification "
650 "message after reauth");
651 return -1;
652 }
653
654 return 0;
655 }
656
657
eap_sim_process_notification(struct eap_sm * sm,struct eap_sim_data * data,const struct eap_hdr * req,size_t reqDataLen,size_t * respDataLen,struct eap_sim_attrs * attr)658 static u8 * eap_sim_process_notification(struct eap_sm *sm,
659 struct eap_sim_data *data,
660 const struct eap_hdr *req,
661 size_t reqDataLen,
662 size_t *respDataLen,
663 struct eap_sim_attrs *attr)
664 {
665 wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Notification");
666 if (data->num_notification > 0) {
667 wpa_printf(MSG_INFO, "EAP-SIM: too many notification "
668 "rounds (only one allowed)");
669 return eap_sim_client_error(data, req, respDataLen,
670 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
671 }
672 data->num_notification++;
673 if (attr->notification == -1) {
674 wpa_printf(MSG_INFO, "EAP-SIM: no AT_NOTIFICATION in "
675 "Notification message");
676 return eap_sim_client_error(data, req, respDataLen,
677 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
678 }
679
680 if ((attr->notification & 0x4000) == 0 &&
681 eap_sim_process_notification_auth(data, req, reqDataLen, attr)) {
682 return eap_sim_client_error(data, req, respDataLen,
683 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
684 }
685
686 eap_sim_report_notification(sm->msg_ctx, attr->notification, 0);
687 if (attr->notification >= 0 && attr->notification < 32768) {
688 data->state = FAILURE;
689 }
690 return eap_sim_response_notification(data, req, respDataLen,
691 attr->notification);
692 }
693
694
eap_sim_process_reauthentication(struct eap_sm * sm,struct eap_sim_data * data,const struct eap_hdr * req,size_t reqDataLen,size_t * respDataLen,struct eap_sim_attrs * attr)695 static u8 * eap_sim_process_reauthentication(struct eap_sm *sm,
696 struct eap_sim_data *data,
697 const struct eap_hdr *req,
698 size_t reqDataLen,
699 size_t *respDataLen,
700 struct eap_sim_attrs *attr)
701 {
702 struct eap_sim_attrs eattr;
703 u8 *decrypted;
704
705 wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Reauthentication");
706
707 if (data->reauth_id == NULL) {
708 wpa_printf(MSG_WARNING, "EAP-SIM: Server is trying "
709 "reauthentication, but no reauth_id available");
710 return eap_sim_client_error(data, req, respDataLen,
711 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
712 }
713
714 data->reauth = 1;
715 if (eap_sim_verify_mac(data->k_aut, (const u8 *) req, reqDataLen,
716 attr->mac, (u8 *) "", 0)) {
717 wpa_printf(MSG_WARNING, "EAP-SIM: Reauthentication "
718 "did not have valid AT_MAC");
719 return eap_sim_client_error(data, req, respDataLen,
720 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
721 }
722
723 if (attr->encr_data == NULL || attr->iv == NULL) {
724 wpa_printf(MSG_WARNING, "EAP-SIM: Reauthentication "
725 "message did not include encrypted data");
726 return eap_sim_client_error(data, req, respDataLen,
727 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
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 reauthentication message");
736 return eap_sim_client_error(data, req, respDataLen,
737 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
738 }
739
740 if (eattr.nonce_s == NULL || eattr.counter < 0) {
741 wpa_printf(MSG_INFO, "EAP-SIM: (encr) No%s%s in reauth packet",
742 !eattr.nonce_s ? " AT_NONCE_S" : "",
743 eattr.counter < 0 ? " AT_COUNTER" : "");
744 os_free(decrypted);
745 return eap_sim_client_error(data, req, respDataLen,
746 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
747 }
748
749 if (eattr.counter < 0 || (size_t) eattr.counter <= data->counter) {
750 wpa_printf(MSG_INFO, "EAP-SIM: (encr) Invalid counter "
751 "(%d <= %d)", eattr.counter, data->counter);
752 data->counter_too_small = eattr.counter;
753 /* Reply using Re-auth w/ AT_COUNTER_TOO_SMALL. The current
754 * reauth_id must not be used to start a new reauthentication.
755 * However, since it was used in the last EAP-Response-Identity
756 * packet, it has to saved for the following fullauth to be
757 * used in MK derivation. */
758 os_free(data->last_eap_identity);
759 data->last_eap_identity = data->reauth_id;
760 data->last_eap_identity_len = data->reauth_id_len;
761 data->reauth_id = NULL;
762 data->reauth_id_len = 0;
763 os_free(decrypted);
764 return eap_sim_response_reauth(data, req, respDataLen, 1);
765 }
766 data->counter = eattr.counter;
767
768 os_memcpy(data->nonce_s, eattr.nonce_s, EAP_SIM_NONCE_S_LEN);
769 wpa_hexdump(MSG_DEBUG, "EAP-SIM: (encr) AT_NONCE_S",
770 data->nonce_s, EAP_SIM_NONCE_S_LEN);
771
772 eap_sim_derive_keys_reauth(data->counter,
773 data->reauth_id, data->reauth_id_len,
774 data->nonce_s, data->mk, data->msk,
775 data->emsk);
776 eap_sim_clear_identities(data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
777 eap_sim_learn_ids(data, &eattr);
778
779 if (data->state != FAILURE)
780 data->state = SUCCESS;
781
782 data->num_id_req = 0;
783 data->num_notification = 0;
784 if (data->counter > EAP_SIM_MAX_FAST_REAUTHS) {
785 wpa_printf(MSG_DEBUG, "EAP-SIM: Maximum number of "
786 "fast reauths performed - force fullauth");
787 eap_sim_clear_identities(data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
788 }
789 os_free(decrypted);
790 return eap_sim_response_reauth(data, req, respDataLen, 0);
791 }
792
793
eap_sim_process(struct eap_sm * sm,void * priv,struct eap_method_ret * ret,const u8 * reqData,size_t reqDataLen,size_t * respDataLen)794 static u8 * eap_sim_process(struct eap_sm *sm, void *priv,
795 struct eap_method_ret *ret,
796 const u8 *reqData, size_t reqDataLen,
797 size_t *respDataLen)
798 {
799 struct eap_sim_data *data = priv;
800 const struct eap_hdr *req;
801 u8 subtype, *res;
802 const u8 *pos;
803 struct eap_sim_attrs attr;
804 size_t len;
805
806 wpa_hexdump(MSG_DEBUG, "EAP-SIM: EAP data", reqData, reqDataLen);
807 if (eap_get_config_identity(sm, &len) == NULL) {
808 wpa_printf(MSG_INFO, "EAP-SIM: Identity not configured");
809 eap_sm_request_identity(sm);
810 ret->ignore = TRUE;
811 return NULL;
812 }
813
814 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SIM,
815 reqData, reqDataLen, &len);
816 if (pos == NULL || len < 1) {
817 ret->ignore = TRUE;
818 return NULL;
819 }
820 req = (const struct eap_hdr *) reqData;
821 len = be_to_host16(req->length);
822
823 ret->ignore = FALSE;
824 ret->methodState = METHOD_MAY_CONT;
825 ret->decision = DECISION_FAIL;
826 ret->allowNotifications = TRUE;
827
828 subtype = *pos++;
829 wpa_printf(MSG_DEBUG, "EAP-SIM: Subtype=%d", subtype);
830 pos += 2; /* Reserved */
831
832 if (eap_sim_parse_attr(pos, reqData + len, &attr, 0, 0)) {
833 res = eap_sim_client_error(data, req, respDataLen,
834 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
835 goto done;
836 }
837
838 switch (subtype) {
839 case EAP_SIM_SUBTYPE_START:
840 res = eap_sim_process_start(sm, data, req,
841 respDataLen, &attr);
842 break;
843 case EAP_SIM_SUBTYPE_CHALLENGE:
844 res = eap_sim_process_challenge(sm, data, req, len,
845 respDataLen, &attr);
846 break;
847 case EAP_SIM_SUBTYPE_NOTIFICATION:
848 res = eap_sim_process_notification(sm, data, req, len,
849 respDataLen, &attr);
850 break;
851 case EAP_SIM_SUBTYPE_REAUTHENTICATION:
852 res = eap_sim_process_reauthentication(sm, data, req, len,
853 respDataLen, &attr);
854 break;
855 case EAP_SIM_SUBTYPE_CLIENT_ERROR:
856 wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Client-Error");
857 res = eap_sim_client_error(data, req, respDataLen,
858 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
859 break;
860 default:
861 wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown subtype=%d", subtype);
862 res = eap_sim_client_error(data, req, respDataLen,
863 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
864 break;
865 }
866
867 done:
868 if (data->state == FAILURE) {
869 ret->decision = DECISION_FAIL;
870 ret->methodState = METHOD_DONE;
871 } else if (data->state == SUCCESS) {
872 ret->decision = DECISION_COND_SUCC;
873 ret->methodState = METHOD_DONE;
874 }
875
876 if (ret->methodState == METHOD_DONE) {
877 ret->allowNotifications = FALSE;
878 }
879
880 return res;
881 }
882
883
eap_sim_has_reauth_data(struct eap_sm * sm,void * priv)884 static Boolean eap_sim_has_reauth_data(struct eap_sm *sm, void *priv)
885 {
886 struct eap_sim_data *data = priv;
887 return data->pseudonym || data->reauth_id;
888 }
889
890
eap_sim_deinit_for_reauth(struct eap_sm * sm,void * priv)891 static void eap_sim_deinit_for_reauth(struct eap_sm *sm, void *priv)
892 {
893 struct eap_sim_data *data = priv;
894 eap_sim_clear_identities(data, CLEAR_EAP_ID);
895 }
896
897
eap_sim_init_for_reauth(struct eap_sm * sm,void * priv)898 static void * eap_sim_init_for_reauth(struct eap_sm *sm, void *priv)
899 {
900 struct eap_sim_data *data = priv;
901 if (hostapd_get_rand(data->nonce_mt, EAP_SIM_NONCE_MT_LEN)) {
902 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to get random data "
903 "for NONCE_MT");
904 os_free(data);
905 return NULL;
906 }
907 data->num_id_req = 0;
908 data->num_notification = 0;
909 data->state = CONTINUE;
910 return priv;
911 }
912
913
eap_sim_get_identity(struct eap_sm * sm,void * priv,size_t * len)914 static const u8 * eap_sim_get_identity(struct eap_sm *sm, void *priv,
915 size_t *len)
916 {
917 struct eap_sim_data *data = priv;
918
919 if (data->reauth_id) {
920 *len = data->reauth_id_len;
921 return data->reauth_id;
922 }
923
924 if (data->pseudonym) {
925 *len = data->pseudonym_len;
926 return data->pseudonym;
927 }
928
929 return NULL;
930 }
931
932
eap_sim_isKeyAvailable(struct eap_sm * sm,void * priv)933 static Boolean eap_sim_isKeyAvailable(struct eap_sm *sm, void *priv)
934 {
935 struct eap_sim_data *data = priv;
936 return data->state == SUCCESS;
937 }
938
939
eap_sim_getKey(struct eap_sm * sm,void * priv,size_t * len)940 static u8 * eap_sim_getKey(struct eap_sm *sm, void *priv, size_t *len)
941 {
942 struct eap_sim_data *data = priv;
943 u8 *key;
944
945 if (data->state != SUCCESS)
946 return NULL;
947
948 key = os_malloc(EAP_SIM_KEYING_DATA_LEN);
949 if (key == NULL)
950 return NULL;
951
952 *len = EAP_SIM_KEYING_DATA_LEN;
953 os_memcpy(key, data->msk, EAP_SIM_KEYING_DATA_LEN);
954
955 return key;
956 }
957
958
eap_sim_get_emsk(struct eap_sm * sm,void * priv,size_t * len)959 static u8 * eap_sim_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
960 {
961 struct eap_sim_data *data = priv;
962 u8 *key;
963
964 if (data->state != SUCCESS)
965 return NULL;
966
967 key = os_malloc(EAP_EMSK_LEN);
968 if (key == NULL)
969 return NULL;
970
971 *len = EAP_EMSK_LEN;
972 os_memcpy(key, data->emsk, EAP_EMSK_LEN);
973
974 return key;
975 }
976
977
eap_peer_sim_register(void)978 int eap_peer_sim_register(void)
979 {
980 struct eap_method *eap;
981 int ret;
982
983 eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
984 EAP_VENDOR_IETF, EAP_TYPE_SIM, "SIM");
985 if (eap == NULL)
986 return -1;
987
988 eap->init = eap_sim_init;
989 eap->deinit = eap_sim_deinit;
990 eap->process = eap_sim_process;
991 eap->isKeyAvailable = eap_sim_isKeyAvailable;
992 eap->getKey = eap_sim_getKey;
993 eap->has_reauth_data = eap_sim_has_reauth_data;
994 eap->deinit_for_reauth = eap_sim_deinit_for_reauth;
995 eap->init_for_reauth = eap_sim_init_for_reauth;
996 eap->get_identity = eap_sim_get_identity;
997 eap->get_emsk = eap_sim_get_emsk;
998
999 ret = eap_peer_method_register(eap);
1000 if (ret)
1001 eap_peer_method_free(eap);
1002 return ret;
1003 }
1004