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