src/eap_server/eap_server_sim.c

   1 /*
   2  * hostapd / EAP-SIM (RFC 4186)
   3  * Copyright (c) 2005-2008, 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_server/eap_i.h"
  19 #include "eap_common/eap_sim_common.h"
  20 #include "eap_server/eap_sim_db.h"
  21
  22
  23 struct eap_sim_data {
  24         u8 mk[EAP_SIM_MK_LEN];
  25         u8 nonce_mt[EAP_SIM_NONCE_MT_LEN];
  26         u8 nonce_s[EAP_SIM_NONCE_S_LEN];
  27         u8 k_aut[EAP_SIM_K_AUT_LEN];
  28         u8 k_encr[EAP_SIM_K_ENCR_LEN];
  29         u8 msk[EAP_SIM_KEYING_DATA_LEN];
  30         u8 emsk[EAP_EMSK_LEN];
  31         u8 kc[EAP_SIM_MAX_CHAL][EAP_SIM_KC_LEN];
  32         u8 sres[EAP_SIM_MAX_CHAL][EAP_SIM_SRES_LEN];
  33         u8 rand[EAP_SIM_MAX_CHAL][GSM_RAND_LEN];
  34         int num_chal;
  35         enum {
  36                 START, CHALLENGE, REAUTH, NOTIFICATION, SUCCESS, FAILURE
  37         } state;
  38         char *next_pseudonym;
  39         char *next_reauth_id;
  40         u16 counter;
  41         struct eap_sim_reauth *reauth;
  42         u16 notification;
  43         int use_result_ind;
  44 };
  45
  46
  47 static const char * eap_sim_state_txt(int state)
  48 {
  49         switch (state) {
  50         case START:
  51                 return "START";
  52         case CHALLENGE:
  53                 return "CHALLENGE";
  54         case REAUTH:
  55                 return "REAUTH";
  56         case SUCCESS:
  57                 return "SUCCESS";
  58         case FAILURE:
  59                 return "FAILURE";
  60         case NOTIFICATION:
  61                 return "NOTIFICATION";
  62         default:
  63                 return "Unknown?!";
  64         }
  65 }
  66
  67
  68 static void eap_sim_state(struct eap_sim_data *data, int state)
  69 {
  70         wpa_printf(MSG_DEBUG, "EAP-SIM: %s -> %s",
  71                    eap_sim_state_txt(data->state),
  72                    eap_sim_state_txt(state));
  73         data->state = state;
  74 }
  75
  76
  77 static void * eap_sim_init(struct eap_sm *sm)
  78 {
  79         struct eap_sim_data *data;
  80
  81         if (sm->eap_sim_db_priv == NULL) {
  82                 wpa_printf(MSG_WARNING, "EAP-SIM: eap_sim_db not configured");
  83                 return NULL;
  84         }
  85
  86         data = os_zalloc(sizeof(*data));
  87         if (data == NULL)
  88                 return NULL;
  89         data->state = START;
  90
  91         return data;
  92 }
  93
  94
  95 static void eap_sim_reset(struct eap_sm *sm, void *priv)
  96 {
  97         struct eap_sim_data *data = priv;
  98         os_free(data->next_pseudonym);
  99         os_free(data->next_reauth_id);
 100         os_free(data);
 101 }
 102
 103
 104 static struct wpabuf * eap_sim_build_start(struct eap_sm *sm,
 105                                            struct eap_sim_data *data, u8 id)
 106 {
 107         struct eap_sim_msg *msg;
 108         u8 ver[2];
 109
 110         wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Start");
 111         msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM,
 112                                EAP_SIM_SUBTYPE_START);
 113         if (eap_sim_db_identity_known(sm->eap_sim_db_priv, sm->identity,
 114                                       sm->identity_len)) {
 115                 wpa_printf(MSG_DEBUG, "   AT_PERMANENT_ID_REQ");
 116                 eap_sim_msg_add(msg, EAP_SIM_AT_PERMANENT_ID_REQ, 0, NULL, 0);
 117         } else {
 118                 /*
 119                  * RFC 4186, Chap. 4.2.4 recommends that identity from EAP is
 120                  * ignored and the SIM/Start is used to request the identity.
 121                  */
 122                 wpa_printf(MSG_DEBUG, "   AT_ANY_ID_REQ");
 123                 eap_sim_msg_add(msg, EAP_SIM_AT_ANY_ID_REQ, 0, NULL, 0);
 124         }
 125         wpa_printf(MSG_DEBUG, "   AT_VERSION_LIST");
 126         ver[0] = 0;
 127         ver[1] = EAP_SIM_VERSION;
 128         eap_sim_msg_add(msg, EAP_SIM_AT_VERSION_LIST, sizeof(ver),
 129                         ver, sizeof(ver));
 130         return eap_sim_msg_finish(msg, NULL, NULL, 0);
 131 }
 132
 133
 134 static int eap_sim_build_encr(struct eap_sm *sm, struct eap_sim_data *data,
 135                               struct eap_sim_msg *msg, u16 counter,
 136                               const u8 *nonce_s)
 137 {
 138         os_free(data->next_pseudonym);
 139         data->next_pseudonym =
 140                 eap_sim_db_get_next_pseudonym(sm->eap_sim_db_priv, 0);
 141         os_free(data->next_reauth_id);
 142         if (data->counter <= EAP_SIM_MAX_FAST_REAUTHS) {
 143                 data->next_reauth_id =
 144                         eap_sim_db_get_next_reauth_id(sm->eap_sim_db_priv, 0);
 145         } else {
 146                 wpa_printf(MSG_DEBUG, "EAP-SIM: Max fast re-authentication "
 147                            "count exceeded - force full authentication");
 148                 data->next_reauth_id = NULL;
 149         }
 150
 151         if (data->next_pseudonym == NULL && data->next_reauth_id == NULL &&
 152             counter == 0 && nonce_s == NULL)
 153                 return 0;
 154
 155         wpa_printf(MSG_DEBUG, "   AT_IV");
 156         wpa_printf(MSG_DEBUG, "   AT_ENCR_DATA");
 157         eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV, EAP_SIM_AT_ENCR_DATA);
 158
 159         if (counter > 0) {
 160                 wpa_printf(MSG_DEBUG, "   *AT_COUNTER (%u)", counter);
 161                 eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, counter, NULL, 0);
 162         }
 163
 164         if (nonce_s) {
 165                 wpa_printf(MSG_DEBUG, "   *AT_NONCE_S");
 166                 eap_sim_msg_add(msg, EAP_SIM_AT_NONCE_S, 0, nonce_s,
 167                                 EAP_SIM_NONCE_S_LEN);
 168         }
 169
 170         if (data->next_pseudonym) {
 171                 wpa_printf(MSG_DEBUG, "   *AT_NEXT_PSEUDONYM (%s)",
 172                            data->next_pseudonym);
 173                 eap_sim_msg_add(msg, EAP_SIM_AT_NEXT_PSEUDONYM,
 174                                 os_strlen(data->next_pseudonym),
 175                                 (u8 *) data->next_pseudonym,
 176                                 os_strlen(data->next_pseudonym));
 177         }
 178
 179         if (data->next_reauth_id) {
 180                 wpa_printf(MSG_DEBUG, "   *AT_NEXT_REAUTH_ID (%s)",
 181                            data->next_reauth_id);
 182                 eap_sim_msg_add(msg, EAP_SIM_AT_NEXT_REAUTH_ID,
 183                                 os_strlen(data->next_reauth_id),
 184                                 (u8 *) data->next_reauth_id,
 185                                 os_strlen(data->next_reauth_id));
 186         }
 187
 188         if (eap_sim_msg_add_encr_end(msg, data->k_encr, EAP_SIM_AT_PADDING)) {
 189                 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to encrypt "
 190                            "AT_ENCR_DATA");
 191                 return -1;
 192         }
 193
 194         return 0;
 195 }
 196
 197
 198 static struct wpabuf * eap_sim_build_challenge(struct eap_sm *sm,
 199                                                struct eap_sim_data *data,
 200                                                u8 id)
 201 {
 202         struct eap_sim_msg *msg;
 203
 204         wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Challenge");
 205         msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM,
 206                                EAP_SIM_SUBTYPE_CHALLENGE);
 207         wpa_printf(MSG_DEBUG, "   AT_RAND");
 208         eap_sim_msg_add(msg, EAP_SIM_AT_RAND, 0, (u8 *) data->rand,
 209                         data->num_chal * GSM_RAND_LEN);
 210
 211         if (eap_sim_build_encr(sm, data, msg, 0, NULL)) {
 212                 eap_sim_msg_free(msg);
 213                 return NULL;
 214         }
 215
 216         if (sm->eap_sim_aka_result_ind) {
 217                 wpa_printf(MSG_DEBUG, "   AT_RESULT_IND");
 218                 eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0);
 219         }
 220
 221         wpa_printf(MSG_DEBUG, "   AT_MAC");
 222         eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
 223         return eap_sim_msg_finish(msg, data->k_aut, data->nonce_mt,
 224                                   EAP_SIM_NONCE_MT_LEN);
 225 }
 226
 227
 228 static struct wpabuf * eap_sim_build_reauth(struct eap_sm *sm,
 229                                             struct eap_sim_data *data, u8 id)
 230 {
 231         struct eap_sim_msg *msg;
 232
 233         wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Re-authentication");
 234
 235         if (os_get_random(data->nonce_s, EAP_SIM_NONCE_S_LEN))
 236                 return NULL;
 237         wpa_hexdump_key(MSG_MSGDUMP, "EAP-SIM: NONCE_S",
 238                         data->nonce_s, EAP_SIM_NONCE_S_LEN);
 239
 240         eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut, data->msk,
 241                             data->emsk);
 242         eap_sim_derive_keys_reauth(data->counter, sm->identity,
 243                                    sm->identity_len, data->nonce_s, data->mk,
 244                                    data->msk, data->emsk);
 245
 246         msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM,
 247                                EAP_SIM_SUBTYPE_REAUTHENTICATION);
 248
 249         if (eap_sim_build_encr(sm, data, msg, data->counter, data->nonce_s)) {
 250                 eap_sim_msg_free(msg);
 251                 return NULL;
 252         }
 253
 254         if (sm->eap_sim_aka_result_ind) {
 255                 wpa_printf(MSG_DEBUG, "   AT_RESULT_IND");
 256                 eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0);
 257         }
 258
 259         wpa_printf(MSG_DEBUG, "   AT_MAC");
 260         eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
 261         return eap_sim_msg_finish(msg, data->k_aut, NULL, 0);
 262 }
 263
 264
 265 static struct wpabuf * eap_sim_build_notification(struct eap_sm *sm,
 266                                                   struct eap_sim_data *data,
 267                                                   u8 id)
 268 {
 269         struct eap_sim_msg *msg;
 270
 271         wpa_printf(MSG_DEBUG, "EAP-SIM: Generating Notification");
 272         msg = eap_sim_msg_init(EAP_CODE_REQUEST, id, EAP_TYPE_SIM,
 273                                EAP_SIM_SUBTYPE_NOTIFICATION);
 274         wpa_printf(MSG_DEBUG, "   AT_NOTIFICATION (%d)", data->notification);
 275         eap_sim_msg_add(msg, EAP_SIM_AT_NOTIFICATION, data->notification,
 276                         NULL, 0);
 277         if (data->use_result_ind) {
 278                 if (data->reauth) {
 279                         wpa_printf(MSG_DEBUG, "   AT_IV");
 280                         wpa_printf(MSG_DEBUG, "   AT_ENCR_DATA");
 281                         eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV,
 282                                                    EAP_SIM_AT_ENCR_DATA);
 283                         wpa_printf(MSG_DEBUG, "   *AT_COUNTER (%u)",
 284                                    data->counter);
 285                         eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, data->counter,
 286                                         NULL, 0);
 287
 288                         if (eap_sim_msg_add_encr_end(msg, data->k_encr,
 289                                                      EAP_SIM_AT_PADDING)) {
 290                                 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to "
 291                                            "encrypt AT_ENCR_DATA");
 292                                 eap_sim_msg_free(msg);
 293                                 return NULL;
 294                         }
 295                 }
 296
 297                 wpa_printf(MSG_DEBUG, "   AT_MAC");
 298                 eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
 299         }
 300         return eap_sim_msg_finish(msg, data->k_aut, NULL, 0);
 301 }
 302
 303
 304 static struct wpabuf * eap_sim_buildReq(struct eap_sm *sm, void *priv, u8 id)
 305 {
 306         struct eap_sim_data *data = priv;
 307
 308         switch (data->state) {
 309         case START:
 310                 return eap_sim_build_start(sm, data, id);
 311         case CHALLENGE:
 312                 return eap_sim_build_challenge(sm, data, id);
 313         case REAUTH:
 314                 return eap_sim_build_reauth(sm, data, id);
 315         case NOTIFICATION:
 316                 return eap_sim_build_notification(sm, data, id);
 317         default:
 318                 wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown state %d in "
 319                            "buildReq", data->state);
 320                 break;
 321         }
 322         return NULL;
 323 }
 324
 325
 326 static Boolean eap_sim_check(struct eap_sm *sm, void *priv,
 327                              struct wpabuf *respData)
 328 {
 329         struct eap_sim_data *data = priv;
 330         const u8 *pos;
 331         size_t len;
 332         u8 subtype;
 333
 334         pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SIM, respData, &len);
 335         if (pos == NULL || len < 3) {
 336                 wpa_printf(MSG_INFO, "EAP-SIM: Invalid frame");
 337                 return TRUE;
 338         }
 339         subtype = *pos;
 340
 341         if (subtype == EAP_SIM_SUBTYPE_CLIENT_ERROR)
 342                 return FALSE;
 343
 344         switch (data->state) {
 345         case START:
 346                 if (subtype != EAP_SIM_SUBTYPE_START) {
 347                         wpa_printf(MSG_INFO, "EAP-SIM: Unexpected response "
 348                                    "subtype %d", subtype);
 349                         return TRUE;
 350                 }
 351                 break;
 352         case CHALLENGE:
 353                 if (subtype != EAP_SIM_SUBTYPE_CHALLENGE) {
 354                         wpa_printf(MSG_INFO, "EAP-SIM: Unexpected response "
 355                                    "subtype %d", subtype);
 356                         return TRUE;
 357                 }
 358                 break;
 359         case REAUTH:
 360                 if (subtype != EAP_SIM_SUBTYPE_REAUTHENTICATION) {
 361                         wpa_printf(MSG_INFO, "EAP-SIM: Unexpected response "
 362                                    "subtype %d", subtype);
 363                         return TRUE;
 364                 }
 365                 break;
 366         case NOTIFICATION:
 367                 if (subtype != EAP_SIM_SUBTYPE_NOTIFICATION) {
 368                         wpa_printf(MSG_INFO, "EAP-SIM: Unexpected response "
 369                                    "subtype %d", subtype);
 370                         return TRUE;
 371                 }
 372                 break;
 373         default:
 374                 wpa_printf(MSG_INFO, "EAP-SIM: Unexpected state (%d) for "
 375                            "processing a response", data->state);
 376                 return TRUE;
 377         }
 378
 379         return FALSE;
 380 }
 381
 382
 383 static int eap_sim_supported_ver(struct eap_sim_data *data, int version)
 384 {
 385         return version == EAP_SIM_VERSION;
 386 }
 387
 388
 389 static void eap_sim_process_start(struct eap_sm *sm,
 390                                   struct eap_sim_data *data,
 391                                   struct wpabuf *respData,
 392                                   struct eap_sim_attrs *attr)
 393 {
 394         const u8 *identity;
 395         size_t identity_len;
 396         u8 ver_list[2];
 397
 398         wpa_printf(MSG_DEBUG, "EAP-SIM: Receive start response");
 399
 400         if (attr->identity) {
 401                 os_free(sm->identity);
 402                 sm->identity = os_malloc(attr->identity_len);
 403                 if (sm->identity) {
 404                         os_memcpy(sm->identity, attr->identity,
 405                                   attr->identity_len);
 406                         sm->identity_len = attr->identity_len;
 407                 }
 408         }
 409
 410         identity = NULL;
 411         identity_len = 0;
 412
 413         if (sm->identity && sm->identity_len > 0 &&
 414             sm->identity[0] == EAP_SIM_PERMANENT_PREFIX) {
 415                 identity = sm->identity;
 416                 identity_len = sm->identity_len;
 417         } else {
 418                 identity = eap_sim_db_get_permanent(sm->eap_sim_db_priv,
 419                                                     sm->identity,
 420                                                     sm->identity_len,
 421                                                     &identity_len);
 422                 if (identity == NULL) {
 423                         data->reauth = eap_sim_db_get_reauth_entry(
 424                                 sm->eap_sim_db_priv, sm->identity,
 425                                 sm->identity_len);
 426                         if (data->reauth) {
 427                                 wpa_printf(MSG_DEBUG, "EAP-SIM: Using fast "
 428                                            "re-authentication");
 429                                 identity = data->reauth->identity;
 430                                 identity_len = data->reauth->identity_len;
 431                                 data->counter = data->reauth->counter;
 432                                 os_memcpy(data->mk, data->reauth->mk,
 433                                           EAP_SIM_MK_LEN);
 434                         }
 435                 }
 436         }
 437
 438         if (identity == NULL) {
 439                 wpa_printf(MSG_DEBUG, "EAP-SIM: Could not get proper permanent"
 440                            " user name");
 441                 eap_sim_state(data, FAILURE);
 442                 return;
 443         }
 444
 445         wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Identity",
 446                           identity, identity_len);
 447
 448         if (data->reauth) {
 449                 eap_sim_state(data, REAUTH);
 450                 return;
 451         }
 452
 453         if (attr->nonce_mt == NULL || attr->selected_version < 0) {
 454                 wpa_printf(MSG_DEBUG, "EAP-SIM: Start/Response missing "
 455                            "required attributes");
 456                 eap_sim_state(data, FAILURE);
 457                 return;
 458         }
 459
 460         if (!eap_sim_supported_ver(data, attr->selected_version)) {
 461                 wpa_printf(MSG_DEBUG, "EAP-SIM: Peer selected unsupported "
 462                            "version %d", attr->selected_version);
 463                 eap_sim_state(data, FAILURE);
 464                 return;
 465         }
 466
 467         data->counter = 0; /* reset re-auth counter since this is full auth */
 468         data->reauth = NULL;
 469
 470         data->num_chal = eap_sim_db_get_gsm_triplets(
 471                 sm->eap_sim_db_priv, identity, identity_len,
 472                 EAP_SIM_MAX_CHAL,
 473                 (u8 *) data->rand, (u8 *) data->kc, (u8 *) data->sres, sm);
 474         if (data->num_chal == EAP_SIM_DB_PENDING) {
 475                 wpa_printf(MSG_DEBUG, "EAP-SIM: GSM authentication triplets "
 476                            "not yet available - pending request");
 477                 sm->method_pending = METHOD_PENDING_WAIT;
 478                 return;
 479         }
 480         if (data->num_chal < 2) {
 481                 wpa_printf(MSG_INFO, "EAP-SIM: Failed to get GSM "
 482                            "authentication triplets for the peer");
 483                 eap_sim_state(data, FAILURE);
 484                 return;
 485         }
 486
 487         identity_len = sm->identity_len;
 488         while (identity_len > 0 && sm->identity[identity_len - 1] == '\0') {
 489                 wpa_printf(MSG_DEBUG, "EAP-SIM: Workaround - drop last null "
 490                            "character from identity");
 491                 identity_len--;
 492         }
 493         wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Identity for MK derivation",
 494                           sm->identity, identity_len);
 495
 496         os_memcpy(data->nonce_mt, attr->nonce_mt, EAP_SIM_NONCE_MT_LEN);
 497         WPA_PUT_BE16(ver_list, EAP_SIM_VERSION);
 498         eap_sim_derive_mk(sm->identity, identity_len, attr->nonce_mt,
 499                           attr->selected_version, ver_list, sizeof(ver_list),
 500                           data->num_chal, (const u8 *) data->kc, data->mk);
 501         eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut, data->msk,
 502                             data->emsk);
 503
 504         eap_sim_state(data, CHALLENGE);
 505 }
 506
 507
 508 static void eap_sim_process_challenge(struct eap_sm *sm,
 509                                       struct eap_sim_data *data,
 510                                       struct wpabuf *respData,
 511                                       struct eap_sim_attrs *attr)
 512 {
 513         const u8 *identity;
 514         size_t identity_len;
 515
 516         if (attr->mac == NULL ||
 517             eap_sim_verify_mac(data->k_aut, respData, attr->mac,
 518                                (u8 *) data->sres,
 519                                data->num_chal * EAP_SIM_SRES_LEN)) {
 520                 wpa_printf(MSG_WARNING, "EAP-SIM: Challenge message "
 521                            "did not include valid AT_MAC");
 522                 eap_sim_state(data, FAILURE);
 523                 return;
 524         }
 525
 526         wpa_printf(MSG_DEBUG, "EAP-SIM: Challenge response includes the "
 527                    "correct AT_MAC");
 528         if (sm->eap_sim_aka_result_ind && attr->result_ind) {
 529                 data->use_result_ind = 1;
 530                 data->notification = EAP_SIM_SUCCESS;
 531                 eap_sim_state(data, NOTIFICATION);
 532         } else
 533                 eap_sim_state(data, SUCCESS);
 534
 535         identity = eap_sim_db_get_permanent(sm->eap_sim_db_priv, sm->identity,
 536                                             sm->identity_len, &identity_len);
 537         if (identity == NULL) {
 538                 identity = sm->identity;
 539                 identity_len = sm->identity_len;
 540         }
 541
 542         if (data->next_pseudonym) {
 543                 eap_sim_db_add_pseudonym(sm->eap_sim_db_priv, identity,
 544                                          identity_len,
 545                                          data->next_pseudonym);
 546                 data->next_pseudonym = NULL;
 547         }
 548         if (data->next_reauth_id) {
 549                 eap_sim_db_add_reauth(sm->eap_sim_db_priv, identity,
 550                                       identity_len,
 551                                       data->next_reauth_id, data->counter + 1,
 552                                       data->mk);
 553                 data->next_reauth_id = NULL;
 554         }
 555 }
 556
 557
 558 static void eap_sim_process_reauth(struct eap_sm *sm,
 559                                    struct eap_sim_data *data,
 560                                    struct wpabuf *respData,
 561                                    struct eap_sim_attrs *attr)
 562 {
 563         struct eap_sim_attrs eattr;
 564         u8 *decrypted = NULL;
 565         const u8 *identity, *id2;
 566         size_t identity_len, id2_len;
 567
 568         if (attr->mac == NULL ||
 569             eap_sim_verify_mac(data->k_aut, respData, attr->mac, data->nonce_s,
 570                                EAP_SIM_NONCE_S_LEN)) {
 571                 wpa_printf(MSG_WARNING, "EAP-SIM: Re-authentication message "
 572                            "did not include valid AT_MAC");
 573                 goto fail;
 574         }
 575
 576         if (attr->encr_data == NULL || attr->iv == NULL) {
 577                 wpa_printf(MSG_WARNING, "EAP-SIM: Reauthentication "
 578                            "message did not include encrypted data");
 579                 goto fail;
 580         }
 581
 582         decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
 583                                        attr->encr_data_len, attr->iv, &eattr,
 584                                        0);
 585         if (decrypted == NULL) {
 586                 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to parse encrypted "
 587                            "data from reauthentication message");
 588                 goto fail;
 589         }
 590
 591         if (eattr.counter != data->counter) {
 592                 wpa_printf(MSG_WARNING, "EAP-SIM: Re-authentication message "
 593                            "used incorrect counter %u, expected %u",
 594                            eattr.counter, data->counter);
 595                 goto fail;
 596         }
 597         os_free(decrypted);
 598         decrypted = NULL;
 599
 600         wpa_printf(MSG_DEBUG, "EAP-SIM: Re-authentication response includes "
 601                    "the correct AT_MAC");
 602         if (sm->eap_sim_aka_result_ind && attr->result_ind) {
 603                 data->use_result_ind = 1;
 604                 data->notification = EAP_SIM_SUCCESS;
 605                 eap_sim_state(data, NOTIFICATION);
 606         } else
 607                 eap_sim_state(data, SUCCESS);
 608
 609         if (data->reauth) {
 610                 identity = data->reauth->identity;
 611                 identity_len = data->reauth->identity_len;
 612         } else {
 613                 identity = sm->identity;
 614                 identity_len = sm->identity_len;
 615         }
 616
 617         id2 = eap_sim_db_get_permanent(sm->eap_sim_db_priv, identity,
 618                                        identity_len, &id2_len);
 619         if (id2) {
 620                 identity = id2;
 621                 identity_len = id2_len;
 622         }
 623
 624         if (data->next_pseudonym) {
 625                 eap_sim_db_add_pseudonym(sm->eap_sim_db_priv, identity,
 626                                          identity_len, data->next_pseudonym);
 627                 data->next_pseudonym = NULL;
 628         }
 629         if (data->next_reauth_id) {
 630                 eap_sim_db_add_reauth(sm->eap_sim_db_priv, identity,
 631                                       identity_len, data->next_reauth_id,
 632                                       data->counter + 1, data->mk);
 633                 data->next_reauth_id = NULL;
 634         } else {
 635                 eap_sim_db_remove_reauth(sm->eap_sim_db_priv, data->reauth);
 636                 data->reauth = NULL;
 637         }
 638
 639         return;
 640
 641 fail:
 642         eap_sim_state(data, FAILURE);
 643         eap_sim_db_remove_reauth(sm->eap_sim_db_priv, data->reauth);
 644         data->reauth = NULL;
 645         os_free(decrypted);
 646 }
 647
 648
 649 static void eap_sim_process_client_error(struct eap_sm *sm,
 650                                          struct eap_sim_data *data,
 651                                          struct wpabuf *respData,
 652                                          struct eap_sim_attrs *attr)
 653 {
 654         wpa_printf(MSG_DEBUG, "EAP-SIM: Client reported error %d",
 655                    attr->client_error_code);
 656         if (data->notification == EAP_SIM_SUCCESS && data->use_result_ind)
 657                 eap_sim_state(data, SUCCESS);
 658         else
 659                 eap_sim_state(data, FAILURE);
 660 }
 661
 662
 663 static void eap_sim_process_notification(struct eap_sm *sm,
 664                                          struct eap_sim_data *data,
 665                                          struct wpabuf *respData,
 666                                          struct eap_sim_attrs *attr)
 667 {
 668         wpa_printf(MSG_DEBUG, "EAP-SIM: Client replied to notification");
 669         if (data->notification == EAP_SIM_SUCCESS && data->use_result_ind)
 670                 eap_sim_state(data, SUCCESS);
 671         else
 672                 eap_sim_state(data, FAILURE);
 673 }
 674
 675
 676 static void eap_sim_process(struct eap_sm *sm, void *priv,
 677                             struct wpabuf *respData)
 678 {
 679         struct eap_sim_data *data = priv;
 680         const u8 *pos, *end;
 681         u8 subtype;
 682         size_t len;
 683         struct eap_sim_attrs attr;
 684
 685         pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SIM, respData, &len);
 686         if (pos == NULL || len < 3)
 687                 return;
 688
 689         end = pos + len;
 690         subtype = *pos;
 691         pos += 3;
 692
 693         if (eap_sim_parse_attr(pos, end, &attr, 0, 0)) {
 694                 wpa_printf(MSG_DEBUG, "EAP-SIM: Failed to parse attributes");
 695                 eap_sim_state(data, FAILURE);
 696                 return;
 697         }
 698
 699         if (subtype == EAP_SIM_SUBTYPE_CLIENT_ERROR) {
 700                 eap_sim_process_client_error(sm, data, respData, &attr);
 701                 return;
 702         }
 703
 704         switch (data->state) {
 705         case START:
 706                 eap_sim_process_start(sm, data, respData, &attr);
 707                 break;
 708         case CHALLENGE:
 709                 eap_sim_process_challenge(sm, data, respData, &attr);
 710                 break;
 711         case REAUTH:
 712                 eap_sim_process_reauth(sm, data, respData, &attr);
 713                 break;
 714         case NOTIFICATION:
 715                 eap_sim_process_notification(sm, data, respData, &attr);
 716                 break;
 717         default:
 718                 wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown state %d in "
 719                            "process", data->state);
 720                 break;
 721         }
 722 }
 723
 724
 725 static Boolean eap_sim_isDone(struct eap_sm *sm, void *priv)
 726 {
 727         struct eap_sim_data *data = priv;
 728         return data->state == SUCCESS || data->state == FAILURE;
 729 }
 730
 731
 732 static u8 * eap_sim_getKey(struct eap_sm *sm, void *priv, size_t *len)
 733 {
 734         struct eap_sim_data *data = priv;
 735         u8 *key;
 736
 737         if (data->state != SUCCESS)
 738                 return NULL;
 739
 740         key = os_malloc(EAP_SIM_KEYING_DATA_LEN);
 741         if (key == NULL)
 742                 return NULL;
 743         os_memcpy(key, data->msk, EAP_SIM_KEYING_DATA_LEN);
 744         *len = EAP_SIM_KEYING_DATA_LEN;
 745         return key;
 746 }
 747
 748
 749 static u8 * eap_sim_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
 750 {
 751         struct eap_sim_data *data = priv;
 752         u8 *key;
 753
 754         if (data->state != SUCCESS)
 755                 return NULL;
 756
 757         key = os_malloc(EAP_EMSK_LEN);
 758         if (key == NULL)
 759                 return NULL;
 760         os_memcpy(key, data->emsk, EAP_EMSK_LEN);
 761         *len = EAP_EMSK_LEN;
 762         return key;
 763 }
 764
 765
 766 static Boolean eap_sim_isSuccess(struct eap_sm *sm, void *priv)
 767 {
 768         struct eap_sim_data *data = priv;
 769         return data->state == SUCCESS;
 770 }
 771
 772
 773 int eap_server_sim_register(void)
 774 {
 775         struct eap_method *eap;
 776         int ret;
 777
 778         eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
 779                                       EAP_VENDOR_IETF, EAP_TYPE_SIM, "SIM");
 780         if (eap == NULL)
 781                 return -1;
 782
 783         eap->init = eap_sim_init;
 784         eap->reset = eap_sim_reset;
 785         eap->buildReq = eap_sim_buildReq;
 786         eap->check = eap_sim_check;
 787         eap->process = eap_sim_process;
 788         eap->isDone = eap_sim_isDone;
 789         eap->getKey = eap_sim_getKey;
 790         eap->isSuccess = eap_sim_isSuccess;
 791         eap->get_emsk = eap_sim_get_emsk;
 792
 793         ret = eap_server_method_register(eap);
 794         if (ret)
 795                 eap_server_method_free(eap);
 796         return ret;
 797 }