1 /* 2 * EAP peer method: EAP-SIM (RFC 4186) 3 * Copyright (c) 2004-2012, Jouni Malinen <j (at) 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 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 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 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 } 133 134 135 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 } 146 147 148 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 } 258 259 260 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 269 270 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 } 293 294 295 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 } 356 357 358 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 } 374 375 376 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 } 427 428 429 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 } 446 447 448 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 } 488 489 490 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 } 521 522 523 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 } 597 598 599 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 } 716 717 718 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 } 750 751 752 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 } 778 779 780 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 } 813 814 815 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 } 915 916 917 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 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 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 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 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 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 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 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 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
