contrib/wpa/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         wpa_printf(MSG_DEBUG, "   AT_NOTIFICATION");
 472         eap_sim_msg_add(msg, EAP_SIM_AT_NOTIFICATION, notification, NULL, 0);
 473         if (k_aut && data->reauth) {
 474                 wpa_printf(MSG_DEBUG, "   AT_IV");
 475                 wpa_printf(MSG_DEBUG, "   AT_ENCR_DATA");
 476                 eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV,
 477                                            EAP_SIM_AT_ENCR_DATA);
 478                 wpa_printf(MSG_DEBUG, "   *AT_COUNTER %d", data->counter);
 479                 eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, data->counter,
 480                                 NULL, 0);
 481                 if (eap_sim_msg_add_encr_end(msg, data->k_encr,
 482                                              EAP_SIM_AT_PADDING)) {
 483                         wpa_printf(MSG_WARNING, "EAP-SIM: Failed to encrypt "
 484                                    "AT_ENCR_DATA");
 485                         eap_sim_msg_free(msg);
 486                         return NULL;
 487                 }
 488         }
 489         if (k_aut) {
 490                 wpa_printf(MSG_DEBUG, "   AT_MAC");
 491                 eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
 492         }
 493         return eap_sim_msg_finish(msg, k_aut, (u8 *) "", 0);
 494 }
 495
 496
 497 static struct wpabuf * eap_sim_process_start(struct eap_sm *sm,
 498                                              struct eap_sim_data *data, u8 id,
 499                                              struct eap_sim_attrs *attr)
 500 {
 501         int selected_version = -1, id_error;
 502         size_t i;
 503         u8 *pos;
 504
 505         wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Start");
 506         if (attr->version_list == NULL) {
 507                 wpa_printf(MSG_INFO, "EAP-SIM: No AT_VERSION_LIST in "
 508                            "SIM/Start");
 509                 return eap_sim_client_error(data, id,
 510                                             EAP_SIM_UNSUPPORTED_VERSION);
 511         }
 512
 513         os_free(data->ver_list);
 514         data->ver_list = os_malloc(attr->version_list_len);
 515         if (data->ver_list == NULL) {
 516                 wpa_printf(MSG_DEBUG, "EAP-SIM: Failed to allocate "
 517                            "memory for version list");
 518                 return eap_sim_client_error(data, id,
 519                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 520         }
 521         os_memcpy(data->ver_list, attr->version_list, attr->version_list_len);
 522         data->ver_list_len = attr->version_list_len;
 523         pos = data->ver_list;
 524         for (i = 0; i < data->ver_list_len / 2; i++) {
 525                 int ver = pos[0] * 256 + pos[1];
 526                 pos += 2;
 527                 if (eap_sim_supported_ver(ver)) {
 528                         selected_version = ver;
 529                         break;
 530                 }
 531         }
 532         if (selected_version < 0) {
 533                 wpa_printf(MSG_INFO, "EAP-SIM: Could not find a supported "
 534                            "version");
 535                 return eap_sim_client_error(data, id,
 536                                             EAP_SIM_UNSUPPORTED_VERSION);
 537         }
 538         wpa_printf(MSG_DEBUG, "EAP-SIM: Selected Version %d",
 539                    selected_version);
 540         data->selected_version = selected_version;
 541
 542         id_error = 0;
 543         switch (attr->id_req) {
 544         case NO_ID_REQ:
 545                 break;
 546         case ANY_ID:
 547                 if (data->num_id_req > 0)
 548                         id_error++;
 549                 data->num_id_req++;
 550                 break;
 551         case FULLAUTH_ID:
 552                 if (data->num_id_req > 1)
 553                         id_error++;
 554                 data->num_id_req++;
 555                 break;
 556         case PERMANENT_ID:
 557                 if (data->num_id_req > 2)
 558                         id_error++;
 559                 data->num_id_req++;
 560                 break;
 561         }
 562         if (id_error) {
 563                 wpa_printf(MSG_INFO, "EAP-SIM: Too many ID requests "
 564                            "used within one authentication");
 565                 return eap_sim_client_error(data, id,
 566                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 567         }
 568
 569         return eap_sim_response_start(sm, data, id, attr->id_req);
 570 }
 571
 572
 573 static struct wpabuf * eap_sim_process_challenge(struct eap_sm *sm,
 574                                                  struct eap_sim_data *data,
 575                                                  u8 id,
 576                                                  const struct wpabuf *reqData,
 577                                                  struct eap_sim_attrs *attr)
 578 {
 579         const u8 *identity;
 580         size_t identity_len;
 581         struct eap_sim_attrs eattr;
 582
 583         wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Challenge");
 584         data->reauth = 0;
 585         if (!attr->mac || !attr->rand) {
 586                 wpa_printf(MSG_WARNING, "EAP-SIM: Challenge message "
 587                            "did not include%s%s",
 588                            !attr->mac ? " AT_MAC" : "",
 589                            !attr->rand ? " AT_RAND" : "");
 590                 return eap_sim_client_error(data, id,
 591                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 592         }
 593
 594         wpa_printf(MSG_DEBUG, "EAP-SIM: %lu challenges",
 595                    (unsigned long) attr->num_chal);
 596         if (attr->num_chal < data->min_num_chal) {
 597                 wpa_printf(MSG_INFO, "EAP-SIM: Insufficient number of "
 598                            "challenges (%lu)", (unsigned long) attr->num_chal);
 599                 return eap_sim_client_error(data, id,
 600                                             EAP_SIM_INSUFFICIENT_NUM_OF_CHAL);
 601         }
 602         if (attr->num_chal > 3) {
 603                 wpa_printf(MSG_INFO, "EAP-SIM: Too many challenges "
 604                            "(%lu)", (unsigned long) attr->num_chal);
 605                 return eap_sim_client_error(data, id,
 606                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 607         }
 608
 609         /* Verify that RANDs are different */
 610         if (os_memcmp(attr->rand, attr->rand + GSM_RAND_LEN,
 611                    GSM_RAND_LEN) == 0 ||
 612             (attr->num_chal > 2 &&
 613              (os_memcmp(attr->rand, attr->rand + 2 * GSM_RAND_LEN,
 614                         GSM_RAND_LEN) == 0 ||
 615               os_memcmp(attr->rand + GSM_RAND_LEN,
 616                         attr->rand + 2 * GSM_RAND_LEN,
 617                         GSM_RAND_LEN) == 0))) {
 618                 wpa_printf(MSG_INFO, "EAP-SIM: Same RAND used multiple times");
 619                 return eap_sim_client_error(data, id,
 620                                             EAP_SIM_RAND_NOT_FRESH);
 621         }
 622
 623         os_memcpy(data->rand, attr->rand, attr->num_chal * GSM_RAND_LEN);
 624         data->num_chal = attr->num_chal;
 625
 626         if (eap_sim_gsm_auth(sm, data)) {
 627                 wpa_printf(MSG_WARNING, "EAP-SIM: GSM authentication failed");
 628                 return eap_sim_client_error(data, id,
 629                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 630         }
 631         if (data->last_eap_identity) {
 632                 identity = data->last_eap_identity;
 633                 identity_len = data->last_eap_identity_len;
 634         } else if (data->pseudonym) {
 635                 identity = data->pseudonym;
 636                 identity_len = data->pseudonym_len;
 637         } else
 638                 identity = eap_get_config_identity(sm, &identity_len);
 639         wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Selected identity for MK "
 640                           "derivation", identity, identity_len);
 641         eap_sim_derive_mk(identity, identity_len, data->nonce_mt,
 642                           data->selected_version, data->ver_list,
 643                           data->ver_list_len, data->num_chal,
 644                           (const u8 *) data->kc, data->mk);
 645         eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut, data->msk,
 646                             data->emsk);
 647         if (eap_sim_verify_mac(data->k_aut, reqData, attr->mac, data->nonce_mt,
 648                                EAP_SIM_NONCE_MT_LEN)) {
 649                 wpa_printf(MSG_WARNING, "EAP-SIM: Challenge message "
 650                            "used invalid AT_MAC");
 651                 return eap_sim_client_error(data, id,
 652                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 653         }
 654
 655         /* Old reauthentication and pseudonym identities must not be used
 656          * anymore. In other words, if no new identities are received, full
 657          * authentication will be used on next reauthentication. */
 658         eap_sim_clear_identities(data, CLEAR_PSEUDONYM | CLEAR_REAUTH_ID |
 659                                  CLEAR_EAP_ID);
 660
 661         if (attr->encr_data) {
 662                 u8 *decrypted;
 663                 decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
 664                                                attr->encr_data_len, attr->iv,
 665                                                &eattr, 0);
 666                 if (decrypted == NULL) {
 667                         return eap_sim_client_error(
 668                                 data, id, EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 669                 }
 670                 eap_sim_learn_ids(data, &eattr);
 671                 os_free(decrypted);
 672         }
 673
 674         if (data->result_ind && attr->result_ind)
 675                 data->use_result_ind = 1;
 676
 677         if (data->state != FAILURE && data->state != RESULT_FAILURE) {
 678                 eap_sim_state(data, data->use_result_ind ?
 679                               RESULT_SUCCESS : SUCCESS);
 680         }
 681
 682         data->num_id_req = 0;
 683         data->num_notification = 0;
 684         /* RFC 4186 specifies that counter is initialized to one after
 685          * fullauth, but initializing it to zero makes it easier to implement
 686          * reauth verification. */
 687         data->counter = 0;
 688         return eap_sim_response_challenge(data, id);
 689 }
 690
 691
 692 static int eap_sim_process_notification_reauth(struct eap_sim_data *data,
 693                                                struct eap_sim_attrs *attr)
 694 {
 695         struct eap_sim_attrs eattr;
 696         u8 *decrypted;
 697
 698         if (attr->encr_data == NULL || attr->iv == NULL) {
 699                 wpa_printf(MSG_WARNING, "EAP-SIM: Notification message after "
 700                            "reauth did not include encrypted data");
 701                 return -1;
 702         }
 703
 704         decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
 705                                        attr->encr_data_len, attr->iv, &eattr,
 706                                        0);
 707         if (decrypted == NULL) {
 708                 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to parse encrypted "
 709                            "data from notification message");
 710                 return -1;
 711         }
 712
 713         if (eattr.counter < 0 || (size_t) eattr.counter != data->counter) {
 714                 wpa_printf(MSG_WARNING, "EAP-SIM: Counter in notification "
 715                            "message does not match with counter in reauth "
 716                            "message");
 717                 os_free(decrypted);
 718                 return -1;
 719         }
 720
 721         os_free(decrypted);
 722         return 0;
 723 }
 724
 725
 726 static int eap_sim_process_notification_auth(struct eap_sim_data *data,
 727                                              const struct wpabuf *reqData,
 728                                              struct eap_sim_attrs *attr)
 729 {
 730         if (attr->mac == NULL) {
 731                 wpa_printf(MSG_INFO, "EAP-SIM: no AT_MAC in after_auth "
 732                            "Notification message");
 733                 return -1;
 734         }
 735
 736         if (eap_sim_verify_mac(data->k_aut, reqData, attr->mac, (u8 *) "", 0))
 737         {
 738                 wpa_printf(MSG_WARNING, "EAP-SIM: Notification message "
 739                            "used invalid AT_MAC");
 740                 return -1;
 741         }
 742
 743         if (data->reauth &&
 744             eap_sim_process_notification_reauth(data, attr)) {
 745                 wpa_printf(MSG_WARNING, "EAP-SIM: Invalid notification "
 746                            "message after reauth");
 747                 return -1;
 748         }
 749
 750         return 0;
 751 }
 752
 753
 754 static struct wpabuf * eap_sim_process_notification(
 755         struct eap_sm *sm, struct eap_sim_data *data, u8 id,
 756         const struct wpabuf *reqData, struct eap_sim_attrs *attr)
 757 {
 758         wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Notification");
 759         if (data->num_notification > 0) {
 760                 wpa_printf(MSG_INFO, "EAP-SIM: too many notification "
 761                            "rounds (only one allowed)");
 762                 return eap_sim_client_error(data, id,
 763                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 764         }
 765         data->num_notification++;
 766         if (attr->notification == -1) {
 767                 wpa_printf(MSG_INFO, "EAP-SIM: no AT_NOTIFICATION in "
 768                            "Notification message");
 769                 return eap_sim_client_error(data, id,
 770                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 771         }
 772
 773         if ((attr->notification & 0x4000) == 0 &&
 774             eap_sim_process_notification_auth(data, reqData, attr)) {
 775                 return eap_sim_client_error(data, id,
 776                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 777         }
 778
 779         eap_sim_report_notification(sm->msg_ctx, attr->notification, 0);
 780         if (attr->notification >= 0 && attr->notification < 32768) {
 781                 eap_sim_state(data, FAILURE);
 782         } else if (attr->notification == EAP_SIM_SUCCESS &&
 783                    data->state == RESULT_SUCCESS)
 784                 eap_sim_state(data, SUCCESS);
 785         return eap_sim_response_notification(data, id, attr->notification);
 786 }
 787
 788
 789 static struct wpabuf * eap_sim_process_reauthentication(
 790         struct eap_sm *sm, struct eap_sim_data *data, u8 id,
 791         const struct wpabuf *reqData, struct eap_sim_attrs *attr)
 792 {
 793         struct eap_sim_attrs eattr;
 794         u8 *decrypted;
 795
 796         wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Reauthentication");
 797
 798         if (data->reauth_id == NULL) {
 799                 wpa_printf(MSG_WARNING, "EAP-SIM: Server is trying "
 800                            "reauthentication, but no reauth_id available");
 801                 return eap_sim_client_error(data, id,
 802                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 803         }
 804
 805         data->reauth = 1;
 806         if (eap_sim_verify_mac(data->k_aut, reqData, attr->mac, (u8 *) "", 0))
 807         {
 808                 wpa_printf(MSG_WARNING, "EAP-SIM: Reauthentication "
 809                            "did not have valid AT_MAC");
 810                 return eap_sim_client_error(data, id,
 811                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 812         }
 813
 814         if (attr->encr_data == NULL || attr->iv == NULL) {
 815                 wpa_printf(MSG_WARNING, "EAP-SIM: Reauthentication "
 816                            "message did not include encrypted data");
 817                 return eap_sim_client_error(data, id,
 818                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 819         }
 820
 821         decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
 822                                        attr->encr_data_len, attr->iv, &eattr,
 823                                        0);
 824         if (decrypted == NULL) {
 825                 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to parse encrypted "
 826                            "data from reauthentication message");
 827                 return eap_sim_client_error(data, id,
 828                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 829         }
 830
 831         if (eattr.nonce_s == NULL || eattr.counter < 0) {
 832                 wpa_printf(MSG_INFO, "EAP-SIM: (encr) No%s%s in reauth packet",
 833                            !eattr.nonce_s ? " AT_NONCE_S" : "",
 834                            eattr.counter < 0 ? " AT_COUNTER" : "");
 835                 os_free(decrypted);
 836                 return eap_sim_client_error(data, id,
 837                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 838         }
 839
 840         if (eattr.counter < 0 || (size_t) eattr.counter <= data->counter) {
 841                 wpa_printf(MSG_INFO, "EAP-SIM: (encr) Invalid counter "
 842                            "(%d <= %d)", eattr.counter, data->counter);
 843                 data->counter_too_small = eattr.counter;
 844                 /* Reply using Re-auth w/ AT_COUNTER_TOO_SMALL. The current
 845                  * reauth_id must not be used to start a new reauthentication.
 846                  * However, since it was used in the last EAP-Response-Identity
 847                  * packet, it has to saved for the following fullauth to be
 848                  * used in MK derivation. */
 849                 os_free(data->last_eap_identity);
 850                 data->last_eap_identity = data->reauth_id;
 851                 data->last_eap_identity_len = data->reauth_id_len;
 852                 data->reauth_id = NULL;
 853                 data->reauth_id_len = 0;
 854                 os_free(decrypted);
 855                 return eap_sim_response_reauth(data, id, 1);
 856         }
 857         data->counter = eattr.counter;
 858
 859         os_memcpy(data->nonce_s, eattr.nonce_s, EAP_SIM_NONCE_S_LEN);
 860         wpa_hexdump(MSG_DEBUG, "EAP-SIM: (encr) AT_NONCE_S",
 861                     data->nonce_s, EAP_SIM_NONCE_S_LEN);
 862
 863         eap_sim_derive_keys_reauth(data->counter,
 864                                    data->reauth_id, data->reauth_id_len,
 865                                    data->nonce_s, data->mk, data->msk,
 866                                    data->emsk);
 867         eap_sim_clear_identities(data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
 868         eap_sim_learn_ids(data, &eattr);
 869
 870         if (data->result_ind && attr->result_ind)
 871                 data->use_result_ind = 1;
 872
 873         if (data->state != FAILURE && data->state != RESULT_FAILURE) {
 874                 eap_sim_state(data, data->use_result_ind ?
 875                               RESULT_SUCCESS : SUCCESS);
 876         }
 877
 878         data->num_id_req = 0;
 879         data->num_notification = 0;
 880         if (data->counter > EAP_SIM_MAX_FAST_REAUTHS) {
 881                 wpa_printf(MSG_DEBUG, "EAP-SIM: Maximum number of "
 882                            "fast reauths performed - force fullauth");
 883                 eap_sim_clear_identities(data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
 884         }
 885         os_free(decrypted);
 886         return eap_sim_response_reauth(data, id, 0);
 887 }
 888
 889
 890 static struct wpabuf * eap_sim_process(struct eap_sm *sm, void *priv,
 891                                        struct eap_method_ret *ret,
 892                                        const struct wpabuf *reqData)
 893 {
 894         struct eap_sim_data *data = priv;
 895         const struct eap_hdr *req;
 896         u8 subtype, id;
 897         struct wpabuf *res;
 898         const u8 *pos;
 899         struct eap_sim_attrs attr;
 900         size_t len;
 901
 902         wpa_hexdump_buf(MSG_DEBUG, "EAP-SIM: EAP data", reqData);
 903         if (eap_get_config_identity(sm, &len) == NULL) {
 904                 wpa_printf(MSG_INFO, "EAP-SIM: Identity not configured");
 905                 eap_sm_request_identity(sm);
 906                 ret->ignore = TRUE;
 907                 return NULL;
 908         }
 909
 910         pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SIM, reqData, &len);
 911         if (pos == NULL || len < 1) {
 912                 ret->ignore = TRUE;
 913                 return NULL;
 914         }
 915         req = wpabuf_head(reqData);
 916         id = req->identifier;
 917         len = be_to_host16(req->length);
 918
 919         ret->ignore = FALSE;
 920         ret->methodState = METHOD_MAY_CONT;
 921         ret->decision = DECISION_FAIL;
 922         ret->allowNotifications = TRUE;
 923
 924         subtype = *pos++;
 925         wpa_printf(MSG_DEBUG, "EAP-SIM: Subtype=%d", subtype);
 926         pos += 2; /* Reserved */
 927
 928         if (eap_sim_parse_attr(pos, wpabuf_head_u8(reqData) + len, &attr, 0,
 929                                0)) {
 930                 res = eap_sim_client_error(data, id,
 931                                            EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 932                 goto done;
 933         }
 934
 935         switch (subtype) {
 936         case EAP_SIM_SUBTYPE_START:
 937                 res = eap_sim_process_start(sm, data, id, &attr);
 938                 break;
 939         case EAP_SIM_SUBTYPE_CHALLENGE:
 940                 res = eap_sim_process_challenge(sm, data, id, reqData, &attr);
 941                 break;
 942         case EAP_SIM_SUBTYPE_NOTIFICATION:
 943                 res = eap_sim_process_notification(sm, data, id, reqData,
 944                                                    &attr);
 945                 break;
 946         case EAP_SIM_SUBTYPE_REAUTHENTICATION:
 947                 res = eap_sim_process_reauthentication(sm, data, id, reqData,
 948                                                        &attr);
 949                 break;
 950         case EAP_SIM_SUBTYPE_CLIENT_ERROR:
 951                 wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Client-Error");
 952                 res = eap_sim_client_error(data, id,
 953                                            EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 954                 break;
 955         default:
 956                 wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown subtype=%d", subtype);
 957                 res = eap_sim_client_error(data, id,
 958                                            EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 959                 break;
 960         }
 961
 962 done:
 963         if (data->state == FAILURE) {
 964                 ret->decision = DECISION_FAIL;
 965                 ret->methodState = METHOD_DONE;
 966         } else if (data->state == SUCCESS) {
 967                 ret->decision = data->use_result_ind ?
 968                         DECISION_UNCOND_SUCC : DECISION_COND_SUCC;
 969                 ret->methodState = data->use_result_ind ?
 970                         METHOD_DONE : METHOD_MAY_CONT;
 971         } else if (data->state == RESULT_FAILURE)
 972                 ret->methodState = METHOD_CONT;
 973         else if (data->state == RESULT_SUCCESS)
 974                 ret->methodState = METHOD_CONT;
 975
 976         if (ret->methodState == METHOD_DONE) {
 977                 ret->allowNotifications = FALSE;
 978         }
 979
 980         return res;
 981 }
 982
 983
 984 static Boolean eap_sim_has_reauth_data(struct eap_sm *sm, void *priv)
 985 {
 986         struct eap_sim_data *data = priv;
 987         return data->pseudonym || data->reauth_id;
 988 }
 989
 990
 991 static void eap_sim_deinit_for_reauth(struct eap_sm *sm, void *priv)
 992 {
 993         struct eap_sim_data *data = priv;
 994         eap_sim_clear_identities(data, CLEAR_EAP_ID);
 995         data->use_result_ind = 0;
 996 }
 997
 998
 999 static void * eap_sim_init_for_reauth(struct eap_sm *sm, void *priv)
1000 {
1001         struct eap_sim_data *data = priv;
1002         if (os_get_random(data->nonce_mt, EAP_SIM_NONCE_MT_LEN)) {
1003                 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to get random data "
1004                            "for NONCE_MT");
1005                 os_free(data);
1006                 return NULL;
1007         }
1008         data->num_id_req = 0;
1009         data->num_notification = 0;
1010         eap_sim_state(data, CONTINUE);
1011         return priv;
1012 }
1013
1014
1015 static const u8 * eap_sim_get_identity(struct eap_sm *sm, void *priv,
1016                                        size_t *len)
1017 {
1018         struct eap_sim_data *data = priv;
1019
1020         if (data->reauth_id) {
1021                 *len = data->reauth_id_len;
1022                 return data->reauth_id;
1023         }
1024
1025         if (data->pseudonym) {
1026                 *len = data->pseudonym_len;
1027                 return data->pseudonym;
1028         }
1029
1030         return NULL;
1031 }
1032
1033
1034 static Boolean eap_sim_isKeyAvailable(struct eap_sm *sm, void *priv)
1035 {
1036         struct eap_sim_data *data = priv;
1037         return data->state == SUCCESS;
1038 }
1039
1040
1041 static u8 * eap_sim_getKey(struct eap_sm *sm, void *priv, size_t *len)
1042 {
1043         struct eap_sim_data *data = priv;
1044         u8 *key;
1045
1046         if (data->state != SUCCESS)
1047                 return NULL;
1048
1049         key = os_malloc(EAP_SIM_KEYING_DATA_LEN);
1050         if (key == NULL)
1051                 return NULL;
1052
1053         *len = EAP_SIM_KEYING_DATA_LEN;
1054         os_memcpy(key, data->msk, EAP_SIM_KEYING_DATA_LEN);
1055
1056         return key;
1057 }
1058
1059
1060 static u8 * eap_sim_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
1061 {
1062         struct eap_sim_data *data = priv;
1063         u8 *key;
1064
1065         if (data->state != SUCCESS)
1066                 return NULL;
1067
1068         key = os_malloc(EAP_EMSK_LEN);
1069         if (key == NULL)
1070                 return NULL;
1071
1072         *len = EAP_EMSK_LEN;
1073         os_memcpy(key, data->emsk, EAP_EMSK_LEN);
1074
1075         return key;
1076 }
1077
1078
1079 int eap_peer_sim_register(void)
1080 {
1081         struct eap_method *eap;
1082         int ret;
1083
1084         eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
1085                                     EAP_VENDOR_IETF, EAP_TYPE_SIM, "SIM");
1086         if (eap == NULL)
1087                 return -1;
1088
1089         eap->init = eap_sim_init;
1090         eap->deinit = eap_sim_deinit;
1091         eap->process = eap_sim_process;
1092         eap->isKeyAvailable = eap_sim_isKeyAvailable;
1093         eap->getKey = eap_sim_getKey;
1094         eap->has_reauth_data = eap_sim_has_reauth_data;
1095         eap->deinit_for_reauth = eap_sim_deinit_for_reauth;
1096         eap->init_for_reauth = eap_sim_init_for_reauth;
1097         eap->get_identity = eap_sim_get_identity;
1098         eap->get_emsk = eap_sim_get_emsk;
1099
1100         ret = eap_peer_method_register(eap);
1101         if (ret)
1102                 eap_peer_method_free(eap);
1103         return ret;
1104 }