src/eap_peer/eap_sim.c

   1 /*
   2  * EAP peer method: EAP-SIM (RFC 4186)
   3  * Copyright (c) 2004-2008, 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_peer/eap_i.h"
  19 #include "eap_config.h"
  20 #include "pcsc_funcs.h"
  21 #include "eap_common/eap_sim_common.h"
  22 #ifdef CONFIG_SIM_SIMULATOR
  23 #include "hlr_auc_gw/milenage.h"
  24 #endif /* CONFIG_SIM_SIMULATOR */
  25
  26
  27 struct eap_sim_data {
  28         u8 *ver_list;
  29         size_t ver_list_len;
  30         int selected_version;
  31         size_t min_num_chal, num_chal;
  32
  33         u8 kc[3][EAP_SIM_KC_LEN];
  34         u8 sres[3][EAP_SIM_SRES_LEN];
  35         u8 nonce_mt[EAP_SIM_NONCE_MT_LEN], nonce_s[EAP_SIM_NONCE_S_LEN];
  36         u8 mk[EAP_SIM_MK_LEN];
  37         u8 k_aut[EAP_SIM_K_AUT_LEN];
  38         u8 k_encr[EAP_SIM_K_ENCR_LEN];
  39         u8 msk[EAP_SIM_KEYING_DATA_LEN];
  40         u8 emsk[EAP_EMSK_LEN];
  41         u8 rand[3][GSM_RAND_LEN];
  42
  43         int num_id_req, num_notification;
  44         u8 *pseudonym;
  45         size_t pseudonym_len;
  46         u8 *reauth_id;
  47         size_t reauth_id_len;
  48         int reauth;
  49         unsigned int counter, counter_too_small;
  50         u8 *last_eap_identity;
  51         size_t last_eap_identity_len;
  52         enum {
  53                 CONTINUE, RESULT_SUCCESS, RESULT_FAILURE, SUCCESS, FAILURE
  54         } state;
  55         int result_ind, use_result_ind;
  56 };
  57
  58
  59 #ifndef CONFIG_NO_STDOUT_DEBUG
  60 static const char * eap_sim_state_txt(int state)
  61 {
  62         switch (state) {
  63         case CONTINUE:
  64                 return "CONTINUE";
  65         case RESULT_SUCCESS:
  66                 return "RESULT_SUCCESS";
  67         case RESULT_FAILURE:
  68                 return "RESULT_FAILURE";
  69         case SUCCESS:
  70                 return "SUCCESS";
  71         case FAILURE:
  72                 return "FAILURE";
  73         default:
  74                 return "?";
  75         }
  76 }
  77 #endif /* CONFIG_NO_STDOUT_DEBUG */
  78
  79
  80 static void eap_sim_state(struct eap_sim_data *data, int state)
  81 {
  82         wpa_printf(MSG_DEBUG, "EAP-SIM: %s -> %s",
  83                    eap_sim_state_txt(data->state),
  84                    eap_sim_state_txt(state));
  85         data->state = state;
  86 }
  87
  88
  89 static void * eap_sim_init(struct eap_sm *sm)
  90 {
  91         struct eap_sim_data *data;
  92         struct eap_peer_config *config = eap_get_config(sm);
  93
  94         data = os_zalloc(sizeof(*data));
  95         if (data == NULL)
  96                 return NULL;
  97
  98         if (os_get_random(data->nonce_mt, EAP_SIM_NONCE_MT_LEN)) {
  99                 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to get random data "
 100                            "for NONCE_MT");
 101                 os_free(data);
 102                 return NULL;
 103         }
 104
 105         data->min_num_chal = 2;
 106         if (config && config->phase1) {
 107                 char *pos = os_strstr(config->phase1, "sim_min_num_chal=");
 108                 if (pos) {
 109                         data->min_num_chal = atoi(pos + 17);
 110                         if (data->min_num_chal < 2 || data->min_num_chal > 3) {
 111                                 wpa_printf(MSG_WARNING, "EAP-SIM: Invalid "
 112                                            "sim_min_num_chal configuration "
 113                                            "(%lu, expected 2 or 3)",
 114                                            (unsigned long) data->min_num_chal);
 115                                 os_free(data);
 116                                 return NULL;
 117                         }
 118                         wpa_printf(MSG_DEBUG, "EAP-SIM: Set minimum number of "
 119                                    "challenges to %lu",
 120                                    (unsigned long) data->min_num_chal);
 121                 }
 122
 123                 data->result_ind = os_strstr(config->phase1, "result_ind=1") !=
 124                         NULL;
 125         }
 126
 127         eap_sim_state(data, CONTINUE);
 128
 129         return data;
 130 }
 131
 132
 133 static void eap_sim_deinit(struct eap_sm *sm, void *priv)
 134 {
 135         struct eap_sim_data *data = priv;
 136         if (data) {
 137                 os_free(data->ver_list);
 138                 os_free(data->pseudonym);
 139                 os_free(data->reauth_id);
 140                 os_free(data->last_eap_identity);
 141                 os_free(data);
 142         }
 143 }
 144
 145
 146 static int eap_sim_gsm_auth(struct eap_sm *sm, struct eap_sim_data *data)
 147 {
 148         struct eap_peer_config *conf;
 149
 150         wpa_printf(MSG_DEBUG, "EAP-SIM: GSM authentication algorithm");
 151
 152         conf = eap_get_config(sm);
 153         if (conf == NULL)
 154                 return -1;
 155         if (conf->pcsc) {
 156                 if (scard_gsm_auth(sm->scard_ctx, data->rand[0],
 157                                    data->sres[0], data->kc[0]) ||
 158                     scard_gsm_auth(sm->scard_ctx, data->rand[1],
 159                                    data->sres[1], data->kc[1]) ||
 160                     (data->num_chal > 2 &&
 161                      scard_gsm_auth(sm->scard_ctx, data->rand[2],
 162                                     data->sres[2], data->kc[2]))) {
 163                         wpa_printf(MSG_DEBUG, "EAP-SIM: GSM SIM "
 164                                    "authentication could not be completed");
 165                         return -1;
 166                 }
 167                 return 0;
 168         }
 169
 170 #ifdef CONFIG_SIM_SIMULATOR
 171         if (conf->password) {
 172                 u8 opc[16], k[16];
 173                 const char *pos;
 174                 wpa_printf(MSG_DEBUG, "EAP-SIM: Use internal GSM-Milenage "
 175                            "implementation for authentication");
 176                 if (conf->password_len < 65) {
 177                         wpa_printf(MSG_DEBUG, "EAP-SIM: invalid GSM-Milenage "
 178                                    "password");
 179                         return -1;
 180                 }
 181                 pos = (const char *) conf->password;
 182                 if (hexstr2bin(pos, k, 16))
 183                         return -1;
 184                 pos += 32;
 185                 if (*pos != ':')
 186                         return -1;
 187                 pos++;
 188
 189                 if (hexstr2bin(pos, opc, 16))
 190                         return -1;
 191
 192                 if (gsm_milenage(opc, k, data->rand[0],
 193                                  data->sres[0], data->kc[0]) ||
 194                     gsm_milenage(opc, k, data->rand[1],
 195                                  data->sres[1], data->kc[1]) ||
 196                     (data->num_chal > 2 &&
 197                      gsm_milenage(opc, k, data->rand[2],
 198                                   data->sres[2], data->kc[2]))) {
 199                         wpa_printf(MSG_DEBUG, "EAP-SIM: GSM-Milenage "
 200                                    "authentication could not be completed");
 201                         return -1;
 202                 }
 203                 return 0;
 204         }
 205 #endif /* CONFIG_SIM_SIMULATOR */
 206
 207 #ifdef CONFIG_SIM_HARDCODED
 208         /* These hardcoded Kc and SRES values are used for testing. RAND to
 209          * KC/SREC mapping is very bogus as far as real authentication is
 210          * concerned, but it is quite useful for cases where the AS is rotating
 211          * the order of pre-configured values. */
 212         {
 213                 size_t i;
 214
 215                 wpa_printf(MSG_DEBUG, "EAP-SIM: Use hardcoded Kc and SRES "
 216                            "values for testing");
 217
 218                 for (i = 0; i < data->num_chal; i++) {
 219                         if (data->rand[i][0] == 0xaa) {
 220                                 os_memcpy(data->kc[i],
 221                                           "\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7",
 222                                           EAP_SIM_KC_LEN);
 223                                 os_memcpy(data->sres[i], "\xd1\xd2\xd3\xd4",
 224                                           EAP_SIM_SRES_LEN);
 225                         } else if (data->rand[i][0] == 0xbb) {
 226                                 os_memcpy(data->kc[i],
 227                                           "\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7",
 228                                           EAP_SIM_KC_LEN);
 229                                 os_memcpy(data->sres[i], "\xe1\xe2\xe3\xe4",
 230                                           EAP_SIM_SRES_LEN);
 231                         } else {
 232                                 os_memcpy(data->kc[i],
 233                                           "\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7",
 234                                           EAP_SIM_KC_LEN);
 235                                 os_memcpy(data->sres[i], "\xf1\xf2\xf3\xf4",
 236                                           EAP_SIM_SRES_LEN);
 237                         }
 238                 }
 239         }
 240
 241         return 0;
 242
 243 #else /* CONFIG_SIM_HARDCODED */
 244
 245         wpa_printf(MSG_DEBUG, "EAP-SIM: No GSM authentication algorithm "
 246                    "enabled");
 247         return -1;
 248
 249 #endif /* CONFIG_SIM_HARDCODED */
 250 }
 251
 252
 253 static int eap_sim_supported_ver(int version)
 254 {
 255         return version == EAP_SIM_VERSION;
 256 }
 257
 258
 259 #define CLEAR_PSEUDONYM 0x01
 260 #define CLEAR_REAUTH_ID 0x02
 261 #define CLEAR_EAP_ID    0x04
 262
 263 static void eap_sim_clear_identities(struct eap_sim_data *data, int id)
 264 {
 265         wpa_printf(MSG_DEBUG, "EAP-SIM: forgetting old%s%s%s",
 266                    id & CLEAR_PSEUDONYM ? " pseudonym" : "",
 267                    id & CLEAR_REAUTH_ID ? " reauth_id" : "",
 268                    id & CLEAR_EAP_ID ? " eap_id" : "");
 269         if (id & CLEAR_PSEUDONYM) {
 270                 os_free(data->pseudonym);
 271                 data->pseudonym = NULL;
 272                 data->pseudonym_len = 0;
 273         }
 274         if (id & CLEAR_REAUTH_ID) {
 275                 os_free(data->reauth_id);
 276                 data->reauth_id = NULL;
 277                 data->reauth_id_len = 0;
 278         }
 279         if (id & CLEAR_EAP_ID) {
 280                 os_free(data->last_eap_identity);
 281                 data->last_eap_identity = NULL;
 282                 data->last_eap_identity_len = 0;
 283         }
 284 }
 285
 286
 287 static int eap_sim_learn_ids(struct eap_sim_data *data,
 288                              struct eap_sim_attrs *attr)
 289 {
 290         if (attr->next_pseudonym) {
 291                 os_free(data->pseudonym);
 292                 data->pseudonym = os_malloc(attr->next_pseudonym_len);
 293                 if (data->pseudonym == NULL) {
 294                         wpa_printf(MSG_INFO, "EAP-SIM: (encr) No memory for "
 295                                    "next pseudonym");
 296                         return -1;
 297                 }
 298                 os_memcpy(data->pseudonym, attr->next_pseudonym,
 299                           attr->next_pseudonym_len);
 300                 data->pseudonym_len = attr->next_pseudonym_len;
 301                 wpa_hexdump_ascii(MSG_DEBUG,
 302                                   "EAP-SIM: (encr) AT_NEXT_PSEUDONYM",
 303                                   data->pseudonym,
 304                                   data->pseudonym_len);
 305         }
 306
 307         if (attr->next_reauth_id) {
 308                 os_free(data->reauth_id);
 309                 data->reauth_id = os_malloc(attr->next_reauth_id_len);
 310                 if (data->reauth_id == NULL) {
 311                         wpa_printf(MSG_INFO, "EAP-SIM: (encr) No memory for "
 312                                    "next reauth_id");
 313                         return -1;
 314                 }
 315                 os_memcpy(data->reauth_id, attr->next_reauth_id,
 316                           attr->next_reauth_id_len);
 317                 data->reauth_id_len = attr->next_reauth_id_len;
 318                 wpa_hexdump_ascii(MSG_DEBUG,
 319                                   "EAP-SIM: (encr) AT_NEXT_REAUTH_ID",
 320                                   data->reauth_id,
 321                                   data->reauth_id_len);
 322         }
 323
 324         return 0;
 325 }
 326
 327
 328 static struct wpabuf * eap_sim_client_error(struct eap_sim_data *data, u8 id,
 329                                             int err)
 330 {
 331         struct eap_sim_msg *msg;
 332
 333         eap_sim_state(data, FAILURE);
 334         data->num_id_req = 0;
 335         data->num_notification = 0;
 336
 337         msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, EAP_TYPE_SIM,
 338                                EAP_SIM_SUBTYPE_CLIENT_ERROR);
 339         eap_sim_msg_add(msg, EAP_SIM_AT_CLIENT_ERROR_CODE, err, NULL, 0);
 340         return eap_sim_msg_finish(msg, NULL, NULL, 0);
 341 }
 342
 343
 344 static struct wpabuf * eap_sim_response_start(struct eap_sm *sm,
 345                                               struct eap_sim_data *data, u8 id,
 346                                               enum eap_sim_id_req id_req)
 347 {
 348         const u8 *identity = NULL;
 349         size_t identity_len = 0;
 350         struct eap_sim_msg *msg;
 351
 352         data->reauth = 0;
 353         if (id_req == ANY_ID && data->reauth_id) {
 354                 identity = data->reauth_id;
 355                 identity_len = data->reauth_id_len;
 356                 data->reauth = 1;
 357         } else if ((id_req == ANY_ID || id_req == FULLAUTH_ID) &&
 358                    data->pseudonym) {
 359                 identity = data->pseudonym;
 360                 identity_len = data->pseudonym_len;
 361                 eap_sim_clear_identities(data, CLEAR_REAUTH_ID);
 362         } else if (id_req != NO_ID_REQ) {
 363                 identity = eap_get_config_identity(sm, &identity_len);
 364                 if (identity) {
 365                         eap_sim_clear_identities(data, CLEAR_PSEUDONYM |
 366                                                  CLEAR_REAUTH_ID);
 367                 }
 368         }
 369         if (id_req != NO_ID_REQ)
 370                 eap_sim_clear_identities(data, CLEAR_EAP_ID);
 371
 372         wpa_printf(MSG_DEBUG, "Generating EAP-SIM Start (id=%d)", id);
 373         msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id,
 374                                EAP_TYPE_SIM, EAP_SIM_SUBTYPE_START);
 375         if (!data->reauth) {
 376                 wpa_hexdump(MSG_DEBUG, "   AT_NONCE_MT",
 377                             data->nonce_mt, EAP_SIM_NONCE_MT_LEN);
 378                 eap_sim_msg_add(msg, EAP_SIM_AT_NONCE_MT, 0,
 379                                 data->nonce_mt, EAP_SIM_NONCE_MT_LEN);
 380                 wpa_printf(MSG_DEBUG, "   AT_SELECTED_VERSION %d",
 381                            data->selected_version);
 382                 eap_sim_msg_add(msg, EAP_SIM_AT_SELECTED_VERSION,
 383                                 data->selected_version, NULL, 0);
 384         }
 385
 386         if (identity) {
 387                 wpa_hexdump_ascii(MSG_DEBUG, "   AT_IDENTITY",
 388                                   identity, identity_len);
 389                 eap_sim_msg_add(msg, EAP_SIM_AT_IDENTITY, identity_len,
 390                                 identity, identity_len);
 391         }
 392
 393         return eap_sim_msg_finish(msg, NULL, NULL, 0);
 394 }
 395
 396
 397 static struct wpabuf * eap_sim_response_challenge(struct eap_sim_data *data,
 398                                                   u8 id)
 399 {
 400         struct eap_sim_msg *msg;
 401
 402         wpa_printf(MSG_DEBUG, "Generating EAP-SIM Challenge (id=%d)", id);
 403         msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, EAP_TYPE_SIM,
 404                                EAP_SIM_SUBTYPE_CHALLENGE);
 405         if (data->use_result_ind) {
 406                 wpa_printf(MSG_DEBUG, "   AT_RESULT_IND");
 407                 eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0);
 408         }
 409         wpa_printf(MSG_DEBUG, "   AT_MAC");
 410         eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
 411         return eap_sim_msg_finish(msg, data->k_aut, (u8 *) data->sres,
 412                                   data->num_chal * EAP_SIM_SRES_LEN);
 413 }
 414
 415
 416 static struct wpabuf * eap_sim_response_reauth(struct eap_sim_data *data,
 417                                                u8 id, int counter_too_small)
 418 {
 419         struct eap_sim_msg *msg;
 420         unsigned int counter;
 421
 422         wpa_printf(MSG_DEBUG, "Generating EAP-SIM Reauthentication (id=%d)",
 423                    id);
 424         msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, EAP_TYPE_SIM,
 425                                EAP_SIM_SUBTYPE_REAUTHENTICATION);
 426         wpa_printf(MSG_DEBUG, "   AT_IV");
 427         wpa_printf(MSG_DEBUG, "   AT_ENCR_DATA");
 428         eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV, EAP_SIM_AT_ENCR_DATA);
 429
 430         if (counter_too_small) {
 431                 wpa_printf(MSG_DEBUG, "   *AT_COUNTER_TOO_SMALL");
 432                 eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER_TOO_SMALL, 0, NULL, 0);
 433                 counter = data->counter_too_small;
 434         } else
 435                 counter = data->counter;
 436
 437         wpa_printf(MSG_DEBUG, "   *AT_COUNTER %d", counter);
 438         eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, counter, NULL, 0);
 439
 440         if (eap_sim_msg_add_encr_end(msg, data->k_encr, EAP_SIM_AT_PADDING)) {
 441                 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to encrypt "
 442                            "AT_ENCR_DATA");
 443                 eap_sim_msg_free(msg);
 444                 return NULL;
 445         }
 446         if (data->use_result_ind) {
 447                 wpa_printf(MSG_DEBUG, "   AT_RESULT_IND");
 448                 eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0);
 449         }
 450         wpa_printf(MSG_DEBUG, "   AT_MAC");
 451         eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
 452         return eap_sim_msg_finish(msg, data->k_aut, data->nonce_s,
 453                                   EAP_SIM_NONCE_S_LEN);
 454 }
 455
 456
 457 static struct wpabuf * eap_sim_response_notification(struct eap_sim_data *data,
 458                                                      u8 id, u16 notification)
 459 {
 460         struct eap_sim_msg *msg;
 461         u8 *k_aut = (notification & 0x4000) == 0 ? data->k_aut : NULL;
 462
 463         wpa_printf(MSG_DEBUG, "Generating EAP-SIM Notification (id=%d)", id);
 464         msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id,
 465                                EAP_TYPE_SIM, EAP_SIM_SUBTYPE_NOTIFICATION);
 466         wpa_printf(MSG_DEBUG, "   AT_NOTIFICATION");
 467         eap_sim_msg_add(msg, EAP_SIM_AT_NOTIFICATION, notification, NULL, 0);
 468         if (k_aut && data->reauth) {
 469                 wpa_printf(MSG_DEBUG, "   AT_IV");
 470                 wpa_printf(MSG_DEBUG, "   AT_ENCR_DATA");
 471                 eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV,
 472                                            EAP_SIM_AT_ENCR_DATA);
 473                 wpa_printf(MSG_DEBUG, "   *AT_COUNTER %d", data->counter);
 474                 eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, data->counter,
 475                                 NULL, 0);
 476                 if (eap_sim_msg_add_encr_end(msg, data->k_encr,
 477                                              EAP_SIM_AT_PADDING)) {
 478                         wpa_printf(MSG_WARNING, "EAP-SIM: Failed to encrypt "
 479                                    "AT_ENCR_DATA");
 480                         eap_sim_msg_free(msg);
 481                         return NULL;
 482                 }
 483         }
 484         if (k_aut) {
 485                 wpa_printf(MSG_DEBUG, "   AT_MAC");
 486                 eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
 487         }
 488         return eap_sim_msg_finish(msg, k_aut, (u8 *) "", 0);
 489 }
 490
 491
 492 static struct wpabuf * eap_sim_process_start(struct eap_sm *sm,
 493                                              struct eap_sim_data *data, u8 id,
 494                                              struct eap_sim_attrs *attr)
 495 {
 496         int selected_version = -1, id_error;
 497         size_t i;
 498         u8 *pos;
 499
 500         wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Start");
 501         if (attr->version_list == NULL) {
 502                 wpa_printf(MSG_INFO, "EAP-SIM: No AT_VERSION_LIST in "
 503                            "SIM/Start");
 504                 return eap_sim_client_error(data, id,
 505                                             EAP_SIM_UNSUPPORTED_VERSION);
 506         }
 507
 508         os_free(data->ver_list);
 509         data->ver_list = os_malloc(attr->version_list_len);
 510         if (data->ver_list == NULL) {
 511                 wpa_printf(MSG_DEBUG, "EAP-SIM: Failed to allocate "
 512                            "memory for version list");
 513                 return eap_sim_client_error(data, id,
 514                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 515         }
 516         os_memcpy(data->ver_list, attr->version_list, attr->version_list_len);
 517         data->ver_list_len = attr->version_list_len;
 518         pos = data->ver_list;
 519         for (i = 0; i < data->ver_list_len / 2; i++) {
 520                 int ver = pos[0] * 256 + pos[1];
 521                 pos += 2;
 522                 if (eap_sim_supported_ver(ver)) {
 523                         selected_version = ver;
 524                         break;
 525                 }
 526         }
 527         if (selected_version < 0) {
 528                 wpa_printf(MSG_INFO, "EAP-SIM: Could not find a supported "
 529                            "version");
 530                 return eap_sim_client_error(data, id,
 531                                             EAP_SIM_UNSUPPORTED_VERSION);
 532         }
 533         wpa_printf(MSG_DEBUG, "EAP-SIM: Selected Version %d",
 534                    selected_version);
 535         data->selected_version = selected_version;
 536
 537         id_error = 0;
 538         switch (attr->id_req) {
 539         case NO_ID_REQ:
 540                 break;
 541         case ANY_ID:
 542                 if (data->num_id_req > 0)
 543                         id_error++;
 544                 data->num_id_req++;
 545                 break;
 546         case FULLAUTH_ID:
 547                 if (data->num_id_req > 1)
 548                         id_error++;
 549                 data->num_id_req++;
 550                 break;
 551         case PERMANENT_ID:
 552                 if (data->num_id_req > 2)
 553                         id_error++;
 554                 data->num_id_req++;
 555                 break;
 556         }
 557         if (id_error) {
 558                 wpa_printf(MSG_INFO, "EAP-SIM: Too many ID requests "
 559                            "used within one authentication");
 560                 return eap_sim_client_error(data, id,
 561                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 562         }
 563
 564         return eap_sim_response_start(sm, data, id, attr->id_req);
 565 }
 566
 567
 568 static struct wpabuf * eap_sim_process_challenge(struct eap_sm *sm,
 569                                                  struct eap_sim_data *data,
 570                                                  u8 id,
 571                                                  const struct wpabuf *reqData,
 572                                                  struct eap_sim_attrs *attr)
 573 {
 574         const u8 *identity;
 575         size_t identity_len;
 576         struct eap_sim_attrs eattr;
 577
 578         wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Challenge");
 579         data->reauth = 0;
 580         if (!attr->mac || !attr->rand) {
 581                 wpa_printf(MSG_WARNING, "EAP-SIM: Challenge message "
 582                            "did not include%s%s",
 583                            !attr->mac ? " AT_MAC" : "",
 584                            !attr->rand ? " AT_RAND" : "");
 585                 return eap_sim_client_error(data, id,
 586                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 587         }
 588
 589         wpa_printf(MSG_DEBUG, "EAP-SIM: %lu challenges",
 590                    (unsigned long) attr->num_chal);
 591         if (attr->num_chal < data->min_num_chal) {
 592                 wpa_printf(MSG_INFO, "EAP-SIM: Insufficient number of "
 593                            "challenges (%lu)", (unsigned long) attr->num_chal);
 594                 return eap_sim_client_error(data, id,
 595                                             EAP_SIM_INSUFFICIENT_NUM_OF_CHAL);
 596         }
 597         if (attr->num_chal > 3) {
 598                 wpa_printf(MSG_INFO, "EAP-SIM: Too many challenges "
 599                            "(%lu)", (unsigned long) attr->num_chal);
 600                 return eap_sim_client_error(data, id,
 601                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 602         }
 603
 604         /* Verify that RANDs are different */
 605         if (os_memcmp(attr->rand, attr->rand + GSM_RAND_LEN,
 606                    GSM_RAND_LEN) == 0 ||
 607             (attr->num_chal > 2 &&
 608              (os_memcmp(attr->rand, attr->rand + 2 * GSM_RAND_LEN,
 609                         GSM_RAND_LEN) == 0 ||
 610               os_memcmp(attr->rand + GSM_RAND_LEN,
 611                         attr->rand + 2 * GSM_RAND_LEN,
 612                         GSM_RAND_LEN) == 0))) {
 613                 wpa_printf(MSG_INFO, "EAP-SIM: Same RAND used multiple times");
 614                 return eap_sim_client_error(data, id,
 615                                             EAP_SIM_RAND_NOT_FRESH);
 616         }
 617
 618         os_memcpy(data->rand, attr->rand, attr->num_chal * GSM_RAND_LEN);
 619         data->num_chal = attr->num_chal;
 620
 621         if (eap_sim_gsm_auth(sm, data)) {
 622                 wpa_printf(MSG_WARNING, "EAP-SIM: GSM authentication failed");
 623                 return eap_sim_client_error(data, id,
 624                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 625         }
 626         if (data->last_eap_identity) {
 627                 identity = data->last_eap_identity;
 628                 identity_len = data->last_eap_identity_len;
 629         } else if (data->pseudonym) {
 630                 identity = data->pseudonym;
 631                 identity_len = data->pseudonym_len;
 632         } else
 633                 identity = eap_get_config_identity(sm, &identity_len);
 634         wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Selected identity for MK "
 635                           "derivation", identity, identity_len);
 636         eap_sim_derive_mk(identity, identity_len, data->nonce_mt,
 637                           data->selected_version, data->ver_list,
 638                           data->ver_list_len, data->num_chal,
 639                           (const u8 *) data->kc, data->mk);
 640         eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut, data->msk,
 641                             data->emsk);
 642         if (eap_sim_verify_mac(data->k_aut, reqData, attr->mac, data->nonce_mt,
 643                                EAP_SIM_NONCE_MT_LEN)) {
 644                 wpa_printf(MSG_WARNING, "EAP-SIM: Challenge message "
 645                            "used invalid AT_MAC");
 646                 return eap_sim_client_error(data, id,
 647                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 648         }
 649
 650         /* Old reauthentication and pseudonym identities must not be used
 651          * anymore. In other words, if no new identities are received, full
 652          * authentication will be used on next reauthentication. */
 653         eap_sim_clear_identities(data, CLEAR_PSEUDONYM | CLEAR_REAUTH_ID |
 654                                  CLEAR_EAP_ID);
 655
 656         if (attr->encr_data) {
 657                 u8 *decrypted;
 658                 decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
 659                                                attr->encr_data_len, attr->iv,
 660                                                &eattr, 0);
 661                 if (decrypted == NULL) {
 662                         return eap_sim_client_error(
 663                                 data, id, EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 664                 }
 665                 eap_sim_learn_ids(data, &eattr);
 666                 os_free(decrypted);
 667         }
 668
 669         if (data->result_ind && attr->result_ind)
 670                 data->use_result_ind = 1;
 671
 672         if (data->state != FAILURE && data->state != RESULT_FAILURE) {
 673                 eap_sim_state(data, data->use_result_ind ?
 674                               RESULT_SUCCESS : SUCCESS);
 675         }
 676
 677         data->num_id_req = 0;
 678         data->num_notification = 0;
 679         /* RFC 4186 specifies that counter is initialized to one after
 680          * fullauth, but initializing it to zero makes it easier to implement
 681          * reauth verification. */
 682         data->counter = 0;
 683         return eap_sim_response_challenge(data, id);
 684 }
 685
 686
 687 static int eap_sim_process_notification_reauth(struct eap_sim_data *data,
 688                                                struct eap_sim_attrs *attr)
 689 {
 690         struct eap_sim_attrs eattr;
 691         u8 *decrypted;
 692
 693         if (attr->encr_data == NULL || attr->iv == NULL) {
 694                 wpa_printf(MSG_WARNING, "EAP-SIM: Notification message after "
 695                            "reauth did not include encrypted data");
 696                 return -1;
 697         }
 698
 699         decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
 700                                        attr->encr_data_len, attr->iv, &eattr,
 701                                        0);
 702         if (decrypted == NULL) {
 703                 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to parse encrypted "
 704                            "data from notification message");
 705                 return -1;
 706         }
 707
 708         if (eattr.counter < 0 || (size_t) eattr.counter != data->counter) {
 709                 wpa_printf(MSG_WARNING, "EAP-SIM: Counter in notification "
 710                            "message does not match with counter in reauth "
 711                            "message");
 712                 os_free(decrypted);
 713                 return -1;
 714         }
 715
 716         os_free(decrypted);
 717         return 0;
 718 }
 719
 720
 721 static int eap_sim_process_notification_auth(struct eap_sim_data *data,
 722                                              const struct wpabuf *reqData,
 723                                              struct eap_sim_attrs *attr)
 724 {
 725         if (attr->mac == NULL) {
 726                 wpa_printf(MSG_INFO, "EAP-SIM: no AT_MAC in after_auth "
 727                            "Notification message");
 728                 return -1;
 729         }
 730
 731         if (eap_sim_verify_mac(data->k_aut, reqData, attr->mac, (u8 *) "", 0))
 732         {
 733                 wpa_printf(MSG_WARNING, "EAP-SIM: Notification message "
 734                            "used invalid AT_MAC");
 735                 return -1;
 736         }
 737
 738         if (data->reauth &&
 739             eap_sim_process_notification_reauth(data, attr)) {
 740                 wpa_printf(MSG_WARNING, "EAP-SIM: Invalid notification "
 741                            "message after reauth");
 742                 return -1;
 743         }
 744
 745         return 0;
 746 }
 747
 748
 749 static struct wpabuf * eap_sim_process_notification(
 750         struct eap_sm *sm, struct eap_sim_data *data, u8 id,
 751         const struct wpabuf *reqData, struct eap_sim_attrs *attr)
 752 {
 753         wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Notification");
 754         if (data->num_notification > 0) {
 755                 wpa_printf(MSG_INFO, "EAP-SIM: too many notification "
 756                            "rounds (only one allowed)");
 757                 return eap_sim_client_error(data, id,
 758                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 759         }
 760         data->num_notification++;
 761         if (attr->notification == -1) {
 762                 wpa_printf(MSG_INFO, "EAP-SIM: no AT_NOTIFICATION in "
 763                            "Notification message");
 764                 return eap_sim_client_error(data, id,
 765                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 766         }
 767
 768         if ((attr->notification & 0x4000) == 0 &&
 769             eap_sim_process_notification_auth(data, reqData, attr)) {
 770                 return eap_sim_client_error(data, id,
 771                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 772         }
 773
 774         eap_sim_report_notification(sm->msg_ctx, attr->notification, 0);
 775         if (attr->notification >= 0 && attr->notification < 32768) {
 776                 eap_sim_state(data, FAILURE);
 777         } else if (attr->notification == EAP_SIM_SUCCESS &&
 778                    data->state == RESULT_SUCCESS)
 779                 eap_sim_state(data, SUCCESS);
 780         return eap_sim_response_notification(data, id, attr->notification);
 781 }
 782
 783
 784 static struct wpabuf * eap_sim_process_reauthentication(
 785         struct eap_sm *sm, struct eap_sim_data *data, u8 id,
 786         const struct wpabuf *reqData, struct eap_sim_attrs *attr)
 787 {
 788         struct eap_sim_attrs eattr;
 789         u8 *decrypted;
 790
 791         wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Reauthentication");
 792
 793         if (data->reauth_id == NULL) {
 794                 wpa_printf(MSG_WARNING, "EAP-SIM: Server is trying "
 795                            "reauthentication, but no reauth_id available");
 796                 return eap_sim_client_error(data, id,
 797                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 798         }
 799
 800         data->reauth = 1;
 801         if (eap_sim_verify_mac(data->k_aut, reqData, attr->mac, (u8 *) "", 0))
 802         {
 803                 wpa_printf(MSG_WARNING, "EAP-SIM: Reauthentication "
 804                            "did not have valid AT_MAC");
 805                 return eap_sim_client_error(data, id,
 806                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 807         }
 808
 809         if (attr->encr_data == NULL || attr->iv == NULL) {
 810                 wpa_printf(MSG_WARNING, "EAP-SIM: Reauthentication "
 811                            "message did not include encrypted data");
 812                 return eap_sim_client_error(data, id,
 813                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 814         }
 815
 816         decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
 817                                        attr->encr_data_len, attr->iv, &eattr,
 818                                        0);
 819         if (decrypted == NULL) {
 820                 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to parse encrypted "
 821                            "data from reauthentication message");
 822                 return eap_sim_client_error(data, id,
 823                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 824         }
 825
 826         if (eattr.nonce_s == NULL || eattr.counter < 0) {
 827                 wpa_printf(MSG_INFO, "EAP-SIM: (encr) No%s%s in reauth packet",
 828                            !eattr.nonce_s ? " AT_NONCE_S" : "",
 829                            eattr.counter < 0 ? " AT_COUNTER" : "");
 830                 os_free(decrypted);
 831                 return eap_sim_client_error(data, id,
 832                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 833         }
 834
 835         if (eattr.counter < 0 || (size_t) eattr.counter <= data->counter) {
 836                 wpa_printf(MSG_INFO, "EAP-SIM: (encr) Invalid counter "
 837                            "(%d <= %d)", eattr.counter, data->counter);
 838                 data->counter_too_small = eattr.counter;
 839                 /* Reply using Re-auth w/ AT_COUNTER_TOO_SMALL. The current
 840                  * reauth_id must not be used to start a new reauthentication.
 841                  * However, since it was used in the last EAP-Response-Identity
 842                  * packet, it has to saved for the following fullauth to be
 843                  * used in MK derivation. */
 844                 os_free(data->last_eap_identity);
 845                 data->last_eap_identity = data->reauth_id;
 846                 data->last_eap_identity_len = data->reauth_id_len;
 847                 data->reauth_id = NULL;
 848                 data->reauth_id_len = 0;
 849                 os_free(decrypted);
 850                 return eap_sim_response_reauth(data, id, 1);
 851         }
 852         data->counter = eattr.counter;
 853
 854         os_memcpy(data->nonce_s, eattr.nonce_s, EAP_SIM_NONCE_S_LEN);
 855         wpa_hexdump(MSG_DEBUG, "EAP-SIM: (encr) AT_NONCE_S",
 856                     data->nonce_s, EAP_SIM_NONCE_S_LEN);
 857
 858         eap_sim_derive_keys_reauth(data->counter,
 859                                    data->reauth_id, data->reauth_id_len,
 860                                    data->nonce_s, data->mk, data->msk,
 861                                    data->emsk);
 862         eap_sim_clear_identities(data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
 863         eap_sim_learn_ids(data, &eattr);
 864
 865         if (data->result_ind && attr->result_ind)
 866                 data->use_result_ind = 1;
 867
 868         if (data->state != FAILURE && data->state != RESULT_FAILURE) {
 869                 eap_sim_state(data, data->use_result_ind ?
 870                               RESULT_SUCCESS : SUCCESS);
 871         }
 872
 873         data->num_id_req = 0;
 874         data->num_notification = 0;
 875         if (data->counter > EAP_SIM_MAX_FAST_REAUTHS) {
 876                 wpa_printf(MSG_DEBUG, "EAP-SIM: Maximum number of "
 877                            "fast reauths performed - force fullauth");
 878                 eap_sim_clear_identities(data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
 879         }
 880         os_free(decrypted);
 881         return eap_sim_response_reauth(data, id, 0);
 882 }
 883
 884
 885 static struct wpabuf * eap_sim_process(struct eap_sm *sm, void *priv,
 886                                        struct eap_method_ret *ret,
 887                                        const struct wpabuf *reqData)
 888 {
 889         struct eap_sim_data *data = priv;
 890         const struct eap_hdr *req;
 891         u8 subtype, id;
 892         struct wpabuf *res;
 893         const u8 *pos;
 894         struct eap_sim_attrs attr;
 895         size_t len;
 896
 897         wpa_hexdump_buf(MSG_DEBUG, "EAP-SIM: EAP data", reqData);
 898         if (eap_get_config_identity(sm, &len) == NULL) {
 899                 wpa_printf(MSG_INFO, "EAP-SIM: Identity not configured");
 900                 eap_sm_request_identity(sm);
 901                 ret->ignore = TRUE;
 902                 return NULL;
 903         }
 904
 905         pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SIM, reqData, &len);
 906         if (pos == NULL || len < 1) {
 907                 ret->ignore = TRUE;
 908                 return NULL;
 909         }
 910         req = wpabuf_head(reqData);
 911         id = req->identifier;
 912         len = be_to_host16(req->length);
 913
 914         ret->ignore = FALSE;
 915         ret->methodState = METHOD_MAY_CONT;
 916         ret->decision = DECISION_FAIL;
 917         ret->allowNotifications = TRUE;
 918
 919         subtype = *pos++;
 920         wpa_printf(MSG_DEBUG, "EAP-SIM: Subtype=%d", subtype);
 921         pos += 2; /* Reserved */
 922
 923         if (eap_sim_parse_attr(pos, wpabuf_head_u8(reqData) + len, &attr, 0,
 924                                0)) {
 925                 res = eap_sim_client_error(data, id,
 926                                            EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 927                 goto done;
 928         }
 929
 930         switch (subtype) {
 931         case EAP_SIM_SUBTYPE_START:
 932                 res = eap_sim_process_start(sm, data, id, &attr);
 933                 break;
 934         case EAP_SIM_SUBTYPE_CHALLENGE:
 935                 res = eap_sim_process_challenge(sm, data, id, reqData, &attr);
 936                 break;
 937         case EAP_SIM_SUBTYPE_NOTIFICATION:
 938                 res = eap_sim_process_notification(sm, data, id, reqData,
 939                                                    &attr);
 940                 break;
 941         case EAP_SIM_SUBTYPE_REAUTHENTICATION:
 942                 res = eap_sim_process_reauthentication(sm, data, id, reqData,
 943                                                        &attr);
 944                 break;
 945         case EAP_SIM_SUBTYPE_CLIENT_ERROR:
 946                 wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Client-Error");
 947                 res = eap_sim_client_error(data, id,
 948                                            EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 949                 break;
 950         default:
 951                 wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown subtype=%d", subtype);
 952                 res = eap_sim_client_error(data, id,
 953                                            EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 954                 break;
 955         }
 956
 957 done:
 958         if (data->state == FAILURE) {
 959                 ret->decision = DECISION_FAIL;
 960                 ret->methodState = METHOD_DONE;
 961         } else if (data->state == SUCCESS) {
 962                 ret->decision = data->use_result_ind ?
 963                         DECISION_UNCOND_SUCC : DECISION_COND_SUCC;
 964                 ret->methodState = data->use_result_ind ?
 965                         METHOD_DONE : METHOD_MAY_CONT;
 966         } else if (data->state == RESULT_FAILURE)
 967                 ret->methodState = METHOD_CONT;
 968         else if (data->state == RESULT_SUCCESS)
 969                 ret->methodState = METHOD_CONT;
 970
 971         if (ret->methodState == METHOD_DONE) {
 972                 ret->allowNotifications = FALSE;
 973         }
 974
 975         return res;
 976 }
 977
 978
 979 static Boolean eap_sim_has_reauth_data(struct eap_sm *sm, void *priv)
 980 {
 981         struct eap_sim_data *data = priv;
 982         return data->pseudonym || data->reauth_id;
 983 }
 984
 985
 986 static void eap_sim_deinit_for_reauth(struct eap_sm *sm, void *priv)
 987 {
 988         struct eap_sim_data *data = priv;
 989         eap_sim_clear_identities(data, CLEAR_EAP_ID);
 990         data->use_result_ind = 0;
 991 }
 992
 993
 994 static void * eap_sim_init_for_reauth(struct eap_sm *sm, void *priv)
 995 {
 996         struct eap_sim_data *data = priv;
 997         if (os_get_random(data->nonce_mt, EAP_SIM_NONCE_MT_LEN)) {
 998                 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to get random data "
 999                            "for NONCE_MT");
1000                 os_free(data);
1001                 return NULL;
1002         }
1003         data->num_id_req = 0;
1004         data->num_notification = 0;
1005         eap_sim_state(data, CONTINUE);
1006         return priv;
1007 }
1008
1009
1010 static const u8 * eap_sim_get_identity(struct eap_sm *sm, void *priv,
1011                                        size_t *len)
1012 {
1013         struct eap_sim_data *data = priv;
1014
1015         if (data->reauth_id) {
1016                 *len = data->reauth_id_len;
1017                 return data->reauth_id;
1018         }
1019
1020         if (data->pseudonym) {
1021                 *len = data->pseudonym_len;
1022                 return data->pseudonym;
1023         }
1024
1025         return NULL;
1026 }
1027
1028
1029 static Boolean eap_sim_isKeyAvailable(struct eap_sm *sm, void *priv)
1030 {
1031         struct eap_sim_data *data = priv;
1032         return data->state == SUCCESS;
1033 }
1034
1035
1036 static u8 * eap_sim_getKey(struct eap_sm *sm, void *priv, size_t *len)
1037 {
1038         struct eap_sim_data *data = priv;
1039         u8 *key;
1040
1041         if (data->state != SUCCESS)
1042                 return NULL;
1043
1044         key = os_malloc(EAP_SIM_KEYING_DATA_LEN);
1045         if (key == NULL)
1046                 return NULL;
1047
1048         *len = EAP_SIM_KEYING_DATA_LEN;
1049         os_memcpy(key, data->msk, EAP_SIM_KEYING_DATA_LEN);
1050
1051         return key;
1052 }
1053
1054
1055 static u8 * eap_sim_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
1056 {
1057         struct eap_sim_data *data = priv;
1058         u8 *key;
1059
1060         if (data->state != SUCCESS)
1061                 return NULL;
1062
1063         key = os_malloc(EAP_EMSK_LEN);
1064         if (key == NULL)
1065                 return NULL;
1066
1067         *len = EAP_EMSK_LEN;
1068         os_memcpy(key, data->emsk, EAP_EMSK_LEN);
1069
1070         return key;
1071 }
1072
1073
1074 int eap_peer_sim_register(void)
1075 {
1076         struct eap_method *eap;
1077         int ret;
1078
1079         eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
1080                                     EAP_VENDOR_IETF, EAP_TYPE_SIM, "SIM");
1081         if (eap == NULL)
1082                 return -1;
1083
1084         eap->init = eap_sim_init;
1085         eap->deinit = eap_sim_deinit;
1086         eap->process = eap_sim_process;
1087         eap->isKeyAvailable = eap_sim_isKeyAvailable;
1088         eap->getKey = eap_sim_getKey;
1089         eap->has_reauth_data = eap_sim_has_reauth_data;
1090         eap->deinit_for_reauth = eap_sim_deinit_for_reauth;
1091         eap->init_for_reauth = eap_sim_init_for_reauth;
1092         eap->get_identity = eap_sim_get_identity;
1093         eap->get_emsk = eap_sim_get_emsk;
1094
1095         ret = eap_peer_method_register(eap);
1096         if (ret)
1097                 eap_peer_method_free(eap);
1098         return ret;
1099 }