contrib/wpa_supplicant/eap_sim.c

   1 /*
   2  * EAP peer method: EAP-SIM (RFC 4186)
   3  * Copyright (c) 2004-2006, 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_i.h"
  19 #include "config_ssid.h"
  20 #include "crypto.h"
  21 #include "pcsc_funcs.h"
  22 #include "eap_sim_common.h"
  23
  24
  25 struct eap_sim_data {
  26         u8 *ver_list;
  27         size_t ver_list_len;
  28         int selected_version;
  29         size_t min_num_chal, num_chal;
  30
  31         u8 kc[3][EAP_SIM_KC_LEN];
  32         u8 sres[3][EAP_SIM_SRES_LEN];
  33         u8 nonce_mt[EAP_SIM_NONCE_MT_LEN], nonce_s[EAP_SIM_NONCE_S_LEN];
  34         u8 mk[EAP_SIM_MK_LEN];
  35         u8 k_aut[EAP_SIM_K_AUT_LEN];
  36         u8 k_encr[EAP_SIM_K_ENCR_LEN];
  37         u8 msk[EAP_SIM_KEYING_DATA_LEN];
  38         u8 emsk[EAP_EMSK_LEN];
  39         u8 rand[3][GSM_RAND_LEN];
  40
  41         int num_id_req, num_notification;
  42         u8 *pseudonym;
  43         size_t pseudonym_len;
  44         u8 *reauth_id;
  45         size_t reauth_id_len;
  46         int reauth;
  47         unsigned int counter, counter_too_small;
  48         u8 *last_eap_identity;
  49         size_t last_eap_identity_len;
  50         enum { CONTINUE, SUCCESS, FAILURE } state;
  51 };
  52
  53
  54 static void * eap_sim_init(struct eap_sm *sm)
  55 {
  56         struct eap_sim_data *data;
  57         struct wpa_ssid *config = eap_get_config(sm);
  58
  59         data = os_zalloc(sizeof(*data));
  60         if (data == NULL)
  61                 return NULL;
  62
  63         if (hostapd_get_rand(data->nonce_mt, EAP_SIM_NONCE_MT_LEN)) {
  64                 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to get random data "
  65                            "for NONCE_MT");
  66                 os_free(data);
  67                 return NULL;
  68         }
  69
  70         data->min_num_chal = 2;
  71         if (config && config->phase1) {
  72                 char *pos = os_strstr(config->phase1, "sim_min_num_chal=");
  73                 if (pos) {
  74                         data->min_num_chal = atoi(pos + 17);
  75                         if (data->min_num_chal < 2 || data->min_num_chal > 3) {
  76                                 wpa_printf(MSG_WARNING, "EAP-SIM: Invalid "
  77                                            "sim_min_num_chal configuration "
  78                                            "(%lu, expected 2 or 3)",
  79                                            (unsigned long) data->min_num_chal);
  80                                 os_free(data);
  81                                 return NULL;
  82                         }
  83                         wpa_printf(MSG_DEBUG, "EAP-SIM: Set minimum number of "
  84                                    "challenges to %lu",
  85                                    (unsigned long) data->min_num_chal);
  86                 }
  87         }
  88
  89         data->state = CONTINUE;
  90
  91         return data;
  92 }
  93
  94
  95 static void eap_sim_deinit(struct eap_sm *sm, void *priv)
  96 {
  97         struct eap_sim_data *data = priv;
  98         if (data) {
  99                 os_free(data->ver_list);
 100                 os_free(data->pseudonym);
 101                 os_free(data->reauth_id);
 102                 os_free(data->last_eap_identity);
 103                 os_free(data);
 104         }
 105 }
 106
 107
 108 static int eap_sim_gsm_auth(struct eap_sm *sm, struct eap_sim_data *data)
 109 {
 110         wpa_printf(MSG_DEBUG, "EAP-SIM: GSM authentication algorithm");
 111 #ifdef PCSC_FUNCS
 112         if (scard_gsm_auth(sm->scard_ctx, data->rand[0],
 113                            data->sres[0], data->kc[0]) ||
 114             scard_gsm_auth(sm->scard_ctx, data->rand[1],
 115                            data->sres[1], data->kc[1]) ||
 116             (data->num_chal > 2 &&
 117              scard_gsm_auth(sm->scard_ctx, data->rand[2],
 118                             data->sres[2], data->kc[2]))) {
 119                 wpa_printf(MSG_DEBUG, "EAP-SIM: GSM SIM authentication could "
 120                            "not be completed");
 121                 return -1;
 122         }
 123 #else /* PCSC_FUNCS */
 124         /* These hardcoded Kc and SRES values are used for testing. RAND to
 125          * KC/SREC mapping is very bogus as far as real authentication is
 126          * concerned, but it is quite useful for cases where the AS is rotating
 127          * the order of pre-configured values. */
 128         {
 129                 size_t i;
 130                 for (i = 0; i < data->num_chal; i++) {
 131                         if (data->rand[i][0] == 0xaa) {
 132                                 os_memcpy(data->kc[i],
 133                                           "\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7",
 134                                           EAP_SIM_KC_LEN);
 135                                 os_memcpy(data->sres[i], "\xd1\xd2\xd3\xd4",
 136                                           EAP_SIM_SRES_LEN);
 137                         } else if (data->rand[i][0] == 0xbb) {
 138                                 os_memcpy(data->kc[i],
 139                                           "\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7",
 140                                           EAP_SIM_KC_LEN);
 141                                 os_memcpy(data->sres[i], "\xe1\xe2\xe3\xe4",
 142                                           EAP_SIM_SRES_LEN);
 143                         } else {
 144                                 os_memcpy(data->kc[i],
 145                                           "\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7",
 146                                           EAP_SIM_KC_LEN);
 147                                 os_memcpy(data->sres[i], "\xf1\xf2\xf3\xf4",
 148                                           EAP_SIM_SRES_LEN);
 149                         }
 150                 }
 151         }
 152 #endif /* PCSC_FUNCS */
 153         return 0;
 154 }
 155
 156
 157 static int eap_sim_supported_ver(int version)
 158 {
 159         return version == EAP_SIM_VERSION;
 160 }
 161
 162
 163 #define CLEAR_PSEUDONYM 0x01
 164 #define CLEAR_REAUTH_ID 0x02
 165 #define CLEAR_EAP_ID    0x04
 166
 167 static void eap_sim_clear_identities(struct eap_sim_data *data, int id)
 168 {
 169         wpa_printf(MSG_DEBUG, "EAP-SIM: forgetting old%s%s%s",
 170                    id & CLEAR_PSEUDONYM ? " pseudonym" : "",
 171                    id & CLEAR_REAUTH_ID ? " reauth_id" : "",
 172                    id & CLEAR_EAP_ID ? " eap_id" : "");
 173         if (id & CLEAR_PSEUDONYM) {
 174                 os_free(data->pseudonym);
 175                 data->pseudonym = NULL;
 176                 data->pseudonym_len = 0;
 177         }
 178         if (id & CLEAR_REAUTH_ID) {
 179                 os_free(data->reauth_id);
 180                 data->reauth_id = NULL;
 181                 data->reauth_id_len = 0;
 182         }
 183         if (id & CLEAR_EAP_ID) {
 184                 os_free(data->last_eap_identity);
 185                 data->last_eap_identity = NULL;
 186                 data->last_eap_identity_len = 0;
 187         }
 188 }
 189
 190
 191 static int eap_sim_learn_ids(struct eap_sim_data *data,
 192                              struct eap_sim_attrs *attr)
 193 {
 194         if (attr->next_pseudonym) {
 195                 os_free(data->pseudonym);
 196                 data->pseudonym = os_malloc(attr->next_pseudonym_len);
 197                 if (data->pseudonym == NULL) {
 198                         wpa_printf(MSG_INFO, "EAP-SIM: (encr) No memory for "
 199                                    "next pseudonym");
 200                         return -1;
 201                 }
 202                 os_memcpy(data->pseudonym, attr->next_pseudonym,
 203                           attr->next_pseudonym_len);
 204                 data->pseudonym_len = attr->next_pseudonym_len;
 205                 wpa_hexdump_ascii(MSG_DEBUG,
 206                                   "EAP-SIM: (encr) AT_NEXT_PSEUDONYM",
 207                                   data->pseudonym,
 208                                   data->pseudonym_len);
 209         }
 210
 211         if (attr->next_reauth_id) {
 212                 os_free(data->reauth_id);
 213                 data->reauth_id = os_malloc(attr->next_reauth_id_len);
 214                 if (data->reauth_id == NULL) {
 215                         wpa_printf(MSG_INFO, "EAP-SIM: (encr) No memory for "
 216                                    "next reauth_id");
 217                         return -1;
 218                 }
 219                 os_memcpy(data->reauth_id, attr->next_reauth_id,
 220                           attr->next_reauth_id_len);
 221                 data->reauth_id_len = attr->next_reauth_id_len;
 222                 wpa_hexdump_ascii(MSG_DEBUG,
 223                                   "EAP-SIM: (encr) AT_NEXT_REAUTH_ID",
 224                                   data->reauth_id,
 225                                   data->reauth_id_len);
 226         }
 227
 228         return 0;
 229 }
 230
 231
 232 static u8 * eap_sim_client_error(struct eap_sim_data *data,
 233                                  const struct eap_hdr *req,
 234                                  size_t *respDataLen, int err)
 235 {
 236         struct eap_sim_msg *msg;
 237
 238         data->state = FAILURE;
 239         data->num_id_req = 0;
 240         data->num_notification = 0;
 241
 242         msg = eap_sim_msg_init(EAP_CODE_RESPONSE, req->identifier,
 243                                EAP_TYPE_SIM, EAP_SIM_SUBTYPE_CLIENT_ERROR);
 244         eap_sim_msg_add(msg, EAP_SIM_AT_CLIENT_ERROR_CODE, err, NULL, 0);
 245         return eap_sim_msg_finish(msg, respDataLen, NULL, NULL, 0);
 246 }
 247
 248
 249 static u8 * eap_sim_response_start(struct eap_sm *sm,
 250                                    struct eap_sim_data *data,
 251                                    const struct eap_hdr *req,
 252                                    size_t *respDataLen,
 253                                    enum eap_sim_id_req id_req)
 254 {
 255         const u8 *identity = NULL;
 256         size_t identity_len = 0;
 257         struct eap_sim_msg *msg;
 258
 259         data->reauth = 0;
 260         if (id_req == ANY_ID && data->reauth_id) {
 261                 identity = data->reauth_id;
 262                 identity_len = data->reauth_id_len;
 263                 data->reauth = 1;
 264         } else if ((id_req == ANY_ID || id_req == FULLAUTH_ID) &&
 265                    data->pseudonym) {
 266                 identity = data->pseudonym;
 267                 identity_len = data->pseudonym_len;
 268                 eap_sim_clear_identities(data, CLEAR_REAUTH_ID);
 269         } else if (id_req != NO_ID_REQ) {
 270                 identity = eap_get_config_identity(sm, &identity_len);
 271                 if (identity) {
 272                         eap_sim_clear_identities(data, CLEAR_PSEUDONYM |
 273                                                  CLEAR_REAUTH_ID);
 274                 }
 275         }
 276         if (id_req != NO_ID_REQ)
 277                 eap_sim_clear_identities(data, CLEAR_EAP_ID);
 278
 279         wpa_printf(MSG_DEBUG, "Generating EAP-SIM Start (id=%d)",
 280                    req->identifier);
 281         msg = eap_sim_msg_init(EAP_CODE_RESPONSE, req->identifier,
 282                                EAP_TYPE_SIM, EAP_SIM_SUBTYPE_START);
 283         wpa_hexdump(MSG_DEBUG, "   AT_NONCE_MT",
 284                     data->nonce_mt, EAP_SIM_NONCE_MT_LEN);
 285         eap_sim_msg_add(msg, EAP_SIM_AT_NONCE_MT, 0,
 286                         data->nonce_mt, EAP_SIM_NONCE_MT_LEN);
 287         wpa_printf(MSG_DEBUG, "   AT_SELECTED_VERSION %d",
 288                    data->selected_version);
 289         eap_sim_msg_add(msg, EAP_SIM_AT_SELECTED_VERSION,
 290                         data->selected_version, NULL, 0);
 291
 292         if (identity) {
 293                 wpa_hexdump_ascii(MSG_DEBUG, "   AT_IDENTITY",
 294                                   identity, identity_len);
 295                 eap_sim_msg_add(msg, EAP_SIM_AT_IDENTITY, identity_len,
 296                                 identity, identity_len);
 297         }
 298
 299         return eap_sim_msg_finish(msg, respDataLen, NULL, NULL, 0);
 300 }
 301
 302
 303 static u8 * eap_sim_response_challenge(struct eap_sim_data *data,
 304                                        const struct eap_hdr *req,
 305                                        size_t *respDataLen)
 306 {
 307         struct eap_sim_msg *msg;
 308
 309         wpa_printf(MSG_DEBUG, "Generating EAP-SIM Challenge (id=%d)",
 310                    req->identifier);
 311         msg = eap_sim_msg_init(EAP_CODE_RESPONSE, req->identifier,
 312                                EAP_TYPE_SIM, EAP_SIM_SUBTYPE_CHALLENGE);
 313         wpa_printf(MSG_DEBUG, "   AT_MAC");
 314         eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
 315         return eap_sim_msg_finish(msg, respDataLen, data->k_aut,
 316                                   (u8 *) data->sres,
 317                                   data->num_chal * EAP_SIM_SRES_LEN);
 318 }
 319
 320
 321 static u8 * eap_sim_response_reauth(struct eap_sim_data *data,
 322                                     const struct eap_hdr *req,
 323                                     size_t *respDataLen, int counter_too_small)
 324 {
 325         struct eap_sim_msg *msg;
 326         unsigned int counter;
 327
 328         wpa_printf(MSG_DEBUG, "Generating EAP-SIM Reauthentication (id=%d)",
 329                    req->identifier);
 330         msg = eap_sim_msg_init(EAP_CODE_RESPONSE, req->identifier,
 331                                EAP_TYPE_SIM,
 332                                EAP_SIM_SUBTYPE_REAUTHENTICATION);
 333         wpa_printf(MSG_DEBUG, "   AT_IV");
 334         wpa_printf(MSG_DEBUG, "   AT_ENCR_DATA");
 335         eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV, EAP_SIM_AT_ENCR_DATA);
 336
 337         if (counter_too_small) {
 338                 wpa_printf(MSG_DEBUG, "   *AT_COUNTER_TOO_SMALL");
 339                 eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER_TOO_SMALL, 0, NULL, 0);
 340                 counter = data->counter_too_small;
 341         } else
 342                 counter = data->counter;
 343
 344         wpa_printf(MSG_DEBUG, "   *AT_COUNTER %d", counter);
 345         eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, counter, NULL, 0);
 346
 347         if (eap_sim_msg_add_encr_end(msg, data->k_encr, EAP_SIM_AT_PADDING)) {
 348                 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to encrypt "
 349                            "AT_ENCR_DATA");
 350                 eap_sim_msg_free(msg);
 351                 return NULL;
 352         }
 353         wpa_printf(MSG_DEBUG, "   AT_MAC");
 354         eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
 355         return eap_sim_msg_finish(msg, respDataLen, data->k_aut, data->nonce_s,
 356                                   EAP_SIM_NONCE_S_LEN);
 357 }
 358
 359
 360 static u8 * eap_sim_response_notification(struct eap_sim_data *data,
 361                                           const struct eap_hdr *req,
 362                                           size_t *respDataLen,
 363                                           u16 notification)
 364 {
 365         struct eap_sim_msg *msg;
 366         u8 *k_aut = (notification & 0x4000) == 0 ? data->k_aut : NULL;
 367
 368         wpa_printf(MSG_DEBUG, "Generating EAP-SIM Notification (id=%d)",
 369                    req->identifier);
 370         msg = eap_sim_msg_init(EAP_CODE_RESPONSE, req->identifier,
 371                                EAP_TYPE_SIM, EAP_SIM_SUBTYPE_NOTIFICATION);
 372         wpa_printf(MSG_DEBUG, "   AT_NOTIFICATION");
 373         eap_sim_msg_add(msg, EAP_SIM_AT_NOTIFICATION, notification, NULL, 0);
 374         if (k_aut && data->reauth) {
 375                 wpa_printf(MSG_DEBUG, "   AT_IV");
 376                 wpa_printf(MSG_DEBUG, "   AT_ENCR_DATA");
 377                 eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV,
 378                                            EAP_SIM_AT_ENCR_DATA);
 379                 wpa_printf(MSG_DEBUG, "   *AT_COUNTER %d", data->counter);
 380                 eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, data->counter,
 381                                 NULL, 0);
 382                 if (eap_sim_msg_add_encr_end(msg, data->k_encr,
 383                                              EAP_SIM_AT_PADDING)) {
 384                         wpa_printf(MSG_WARNING, "EAP-SIM: Failed to encrypt "
 385                                    "AT_ENCR_DATA");
 386                         eap_sim_msg_free(msg);
 387                         return NULL;
 388                 }
 389         }
 390         if (k_aut) {
 391                 wpa_printf(MSG_DEBUG, "   AT_MAC");
 392                 eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
 393         }
 394         return eap_sim_msg_finish(msg, respDataLen, k_aut, (u8 *) "", 0);
 395 }
 396
 397
 398 static u8 * eap_sim_process_start(struct eap_sm *sm, struct eap_sim_data *data,
 399                                   const struct eap_hdr *req,
 400                                   size_t *respDataLen,
 401                                   struct eap_sim_attrs *attr)
 402 {
 403         int selected_version = -1, id_error;
 404         size_t i;
 405         u8 *pos;
 406
 407         wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Start");
 408         if (attr->version_list == NULL) {
 409                 wpa_printf(MSG_INFO, "EAP-SIM: No AT_VERSION_LIST in "
 410                            "SIM/Start");
 411                 return eap_sim_client_error(data, req, respDataLen,
 412                                             EAP_SIM_UNSUPPORTED_VERSION);
 413         }
 414
 415         os_free(data->ver_list);
 416         data->ver_list = os_malloc(attr->version_list_len);
 417         if (data->ver_list == NULL) {
 418                 wpa_printf(MSG_DEBUG, "EAP-SIM: Failed to allocate "
 419                            "memory for version list");
 420                 return eap_sim_client_error(data, req, respDataLen,
 421                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 422         }
 423         os_memcpy(data->ver_list, attr->version_list, attr->version_list_len);
 424         data->ver_list_len = attr->version_list_len;
 425         pos = data->ver_list;
 426         for (i = 0; i < data->ver_list_len / 2; i++) {
 427                 int ver = pos[0] * 256 + pos[1];
 428                 pos += 2;
 429                 if (eap_sim_supported_ver(ver)) {
 430                         selected_version = ver;
 431                         break;
 432                 }
 433         }
 434         if (selected_version < 0) {
 435                 wpa_printf(MSG_INFO, "EAP-SIM: Could not find a supported "
 436                            "version");
 437                 return eap_sim_client_error(data, req, respDataLen,
 438                                             EAP_SIM_UNSUPPORTED_VERSION);
 439         }
 440         wpa_printf(MSG_DEBUG, "EAP-SIM: Selected Version %d",
 441                    selected_version);
 442         data->selected_version = selected_version;
 443
 444         id_error = 0;
 445         switch (attr->id_req) {
 446         case NO_ID_REQ:
 447                 break;
 448         case ANY_ID:
 449                 if (data->num_id_req > 0)
 450                         id_error++;
 451                 data->num_id_req++;
 452                 break;
 453         case FULLAUTH_ID:
 454                 if (data->num_id_req > 1)
 455                         id_error++;
 456                 data->num_id_req++;
 457                 break;
 458         case PERMANENT_ID:
 459                 if (data->num_id_req > 2)
 460                         id_error++;
 461                 data->num_id_req++;
 462                 break;
 463         }
 464         if (id_error) {
 465                 wpa_printf(MSG_INFO, "EAP-SIM: Too many ID requests "
 466                            "used within one authentication");
 467                 return eap_sim_client_error(data, req, respDataLen,
 468                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 469         }
 470
 471         return eap_sim_response_start(sm, data, req, respDataLen,
 472                                       attr->id_req);
 473 }
 474
 475
 476 static u8 * eap_sim_process_challenge(struct eap_sm *sm,
 477                                       struct eap_sim_data *data,
 478                                       const struct eap_hdr *req,
 479                                       size_t reqDataLen,
 480                                       size_t *respDataLen,
 481                                       struct eap_sim_attrs *attr)
 482 {
 483         const u8 *identity;
 484         size_t identity_len;
 485         struct eap_sim_attrs eattr;
 486
 487         wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Challenge");
 488         data->reauth = 0;
 489         if (!attr->mac || !attr->rand) {
 490                 wpa_printf(MSG_WARNING, "EAP-SIM: Challenge message "
 491                            "did not include%s%s",
 492                            !attr->mac ? " AT_MAC" : "",
 493                            !attr->rand ? " AT_RAND" : "");
 494                 return eap_sim_client_error(data, req, respDataLen,
 495                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 496         }
 497
 498         wpa_printf(MSG_DEBUG, "EAP-SIM: %lu challenges",
 499                    (unsigned long) attr->num_chal);
 500         if (attr->num_chal < data->min_num_chal) {
 501                 wpa_printf(MSG_INFO, "EAP-SIM: Insufficient number of "
 502                            "challenges (%lu)", (unsigned long) attr->num_chal);
 503                 return eap_sim_client_error(data, req, respDataLen,
 504                                             EAP_SIM_INSUFFICIENT_NUM_OF_CHAL);
 505         }
 506         if (attr->num_chal > 3) {
 507                 wpa_printf(MSG_INFO, "EAP-SIM: Too many challenges "
 508                            "(%lu)", (unsigned long) attr->num_chal);
 509                 return eap_sim_client_error(data, req, respDataLen,
 510                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 511         }
 512
 513         /* Verify that RANDs are different */
 514         if (os_memcmp(attr->rand, attr->rand + GSM_RAND_LEN,
 515                    GSM_RAND_LEN) == 0 ||
 516             (attr->num_chal > 2 &&
 517              (os_memcmp(attr->rand, attr->rand + 2 * GSM_RAND_LEN,
 518                         GSM_RAND_LEN) == 0 ||
 519               os_memcmp(attr->rand + GSM_RAND_LEN,
 520                         attr->rand + 2 * GSM_RAND_LEN,
 521                         GSM_RAND_LEN) == 0))) {
 522                 wpa_printf(MSG_INFO, "EAP-SIM: Same RAND used multiple times");
 523                 return eap_sim_client_error(data, req, respDataLen,
 524                                             EAP_SIM_RAND_NOT_FRESH);
 525         }
 526
 527         os_memcpy(data->rand, attr->rand, attr->num_chal * GSM_RAND_LEN);
 528         data->num_chal = attr->num_chal;
 529
 530         if (eap_sim_gsm_auth(sm, data)) {
 531                 wpa_printf(MSG_WARNING, "EAP-SIM: GSM authentication failed");
 532                 return eap_sim_client_error(data, req, respDataLen,
 533                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 534         }
 535         if (data->last_eap_identity) {
 536                 identity = data->last_eap_identity;
 537                 identity_len = data->last_eap_identity_len;
 538         } else if (data->pseudonym) {
 539                 identity = data->pseudonym;
 540                 identity_len = data->pseudonym_len;
 541         } else
 542                 identity = eap_get_config_identity(sm, &identity_len);
 543         wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Selected identity for MK "
 544                           "derivation", identity, identity_len);
 545         eap_sim_derive_mk(identity, identity_len, data->nonce_mt,
 546                           data->selected_version, data->ver_list,
 547                           data->ver_list_len, data->num_chal,
 548                           (const u8 *) data->kc, data->mk);
 549         eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut, data->msk,
 550                             data->emsk);
 551         if (eap_sim_verify_mac(data->k_aut, (const u8 *) req, reqDataLen,
 552                                attr->mac, data->nonce_mt,
 553                                EAP_SIM_NONCE_MT_LEN)) {
 554                 wpa_printf(MSG_WARNING, "EAP-SIM: Challenge message "
 555                            "used invalid AT_MAC");
 556                 return eap_sim_client_error(data, req, respDataLen,
 557                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 558         }
 559
 560         /* Old reauthentication and pseudonym identities must not be used
 561          * anymore. In other words, if no new identities are received, full
 562          * authentication will be used on next reauthentication. */
 563         eap_sim_clear_identities(data, CLEAR_PSEUDONYM | CLEAR_REAUTH_ID |
 564                                  CLEAR_EAP_ID);
 565
 566         if (attr->encr_data) {
 567                 u8 *decrypted;
 568                 decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
 569                                                attr->encr_data_len, attr->iv,
 570                                                &eattr, 0);
 571                 if (decrypted == NULL) {
 572                         return eap_sim_client_error(
 573                                 data, req, respDataLen,
 574                                 EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 575                 }
 576                 eap_sim_learn_ids(data, &eattr);
 577                 os_free(decrypted);
 578         }
 579
 580         if (data->state != FAILURE)
 581                 data->state = SUCCESS;
 582
 583         data->num_id_req = 0;
 584         data->num_notification = 0;
 585         /* RFC 4186 specifies that counter is initialized to one after
 586          * fullauth, but initializing it to zero makes it easier to implement
 587          * reauth verification. */
 588         data->counter = 0;
 589         return eap_sim_response_challenge(data, req, respDataLen);
 590 }
 591
 592
 593 static int eap_sim_process_notification_reauth(struct eap_sim_data *data,
 594                                                struct eap_sim_attrs *attr)
 595 {
 596         struct eap_sim_attrs eattr;
 597         u8 *decrypted;
 598
 599         if (attr->encr_data == NULL || attr->iv == NULL) {
 600                 wpa_printf(MSG_WARNING, "EAP-SIM: Notification message after "
 601                            "reauth did not include encrypted data");
 602                 return -1;
 603         }
 604
 605         decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
 606                                        attr->encr_data_len, attr->iv, &eattr,
 607                                        0);
 608         if (decrypted == NULL) {
 609                 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to parse encrypted "
 610                            "data from notification message");
 611                 return -1;
 612         }
 613
 614         if (eattr.counter < 0 || (size_t) eattr.counter != data->counter) {
 615                 wpa_printf(MSG_WARNING, "EAP-SIM: Counter in notification "
 616                            "message does not match with counter in reauth "
 617                            "message");
 618                 os_free(decrypted);
 619                 return -1;
 620         }
 621
 622         os_free(decrypted);
 623         return 0;
 624 }
 625
 626
 627 static int eap_sim_process_notification_auth(struct eap_sim_data *data,
 628                                              const struct eap_hdr *req,
 629                                              size_t reqDataLen,
 630                                              struct eap_sim_attrs *attr)
 631 {
 632         if (attr->mac == NULL) {
 633                 wpa_printf(MSG_INFO, "EAP-SIM: no AT_MAC in after_auth "
 634                            "Notification message");
 635                 return -1;
 636         }
 637
 638         if (eap_sim_verify_mac(data->k_aut, (u8 *) req, reqDataLen, attr->mac,
 639                                (u8 *) "", 0)) {
 640                 wpa_printf(MSG_WARNING, "EAP-SIM: Notification message "
 641                            "used invalid AT_MAC");
 642                 return -1;
 643         }
 644
 645         if (data->reauth &&
 646             eap_sim_process_notification_reauth(data, attr)) {
 647                 wpa_printf(MSG_WARNING, "EAP-SIM: Invalid notification "
 648                            "message after reauth");
 649                 return -1;
 650         }
 651
 652         return 0;
 653 }
 654
 655
 656 static u8 * eap_sim_process_notification(struct eap_sm *sm,
 657                                          struct eap_sim_data *data,
 658                                          const struct eap_hdr *req,
 659                                          size_t reqDataLen,
 660                                          size_t *respDataLen,
 661                                          struct eap_sim_attrs *attr)
 662 {
 663         wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Notification");
 664         if (data->num_notification > 0) {
 665                 wpa_printf(MSG_INFO, "EAP-SIM: too many notification "
 666                            "rounds (only one allowed)");
 667                 return eap_sim_client_error(data, req, respDataLen,
 668                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 669         }
 670         data->num_notification++;
 671         if (attr->notification == -1) {
 672                 wpa_printf(MSG_INFO, "EAP-SIM: no AT_NOTIFICATION in "
 673                            "Notification message");
 674                 return eap_sim_client_error(data, req, respDataLen,
 675                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 676         }
 677
 678         if ((attr->notification & 0x4000) == 0 &&
 679             eap_sim_process_notification_auth(data, req, reqDataLen, attr)) {
 680                 return eap_sim_client_error(data, req, respDataLen,
 681                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 682         }
 683
 684         eap_sim_report_notification(sm->msg_ctx, attr->notification, 0);
 685         if (attr->notification >= 0 && attr->notification < 32768) {
 686                 data->state = FAILURE;
 687         }
 688         return eap_sim_response_notification(data, req, respDataLen,
 689                                              attr->notification);
 690 }
 691
 692
 693 static u8 * eap_sim_process_reauthentication(struct eap_sm *sm,
 694                                              struct eap_sim_data *data,
 695                                              const struct eap_hdr *req,
 696                                              size_t reqDataLen,
 697                                              size_t *respDataLen,
 698                                              struct eap_sim_attrs *attr)
 699 {
 700         struct eap_sim_attrs eattr;
 701         u8 *decrypted;
 702
 703         wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Reauthentication");
 704
 705         if (data->reauth_id == NULL) {
 706                 wpa_printf(MSG_WARNING, "EAP-SIM: Server is trying "
 707                            "reauthentication, but no reauth_id available");
 708                 return eap_sim_client_error(data, req, respDataLen,
 709                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 710         }
 711
 712         data->reauth = 1;
 713         if (eap_sim_verify_mac(data->k_aut, (const u8 *) req, reqDataLen,
 714                                attr->mac, (u8 *) "", 0)) {
 715                 wpa_printf(MSG_WARNING, "EAP-SIM: Reauthentication "
 716                            "did not have valid AT_MAC");
 717                 return eap_sim_client_error(data, req, respDataLen,
 718                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 719         }
 720
 721         if (attr->encr_data == NULL || attr->iv == NULL) {
 722                 wpa_printf(MSG_WARNING, "EAP-SIM: Reauthentication "
 723                            "message did not include encrypted data");
 724                 return eap_sim_client_error(data, req, respDataLen,
 725                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 726         }
 727
 728         decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
 729                                        attr->encr_data_len, attr->iv, &eattr,
 730                                        0);
 731         if (decrypted == NULL) {
 732                 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to parse encrypted "
 733                            "data from reauthentication message");
 734                 return eap_sim_client_error(data, req, respDataLen,
 735                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 736         }
 737
 738         if (eattr.nonce_s == NULL || eattr.counter < 0) {
 739                 wpa_printf(MSG_INFO, "EAP-SIM: (encr) No%s%s in reauth packet",
 740                            !eattr.nonce_s ? " AT_NONCE_S" : "",
 741                            eattr.counter < 0 ? " AT_COUNTER" : "");
 742                 os_free(decrypted);
 743                 return eap_sim_client_error(data, req, respDataLen,
 744                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 745         }
 746
 747         if (eattr.counter < 0 || (size_t) eattr.counter <= data->counter) {
 748                 wpa_printf(MSG_INFO, "EAP-SIM: (encr) Invalid counter "
 749                            "(%d <= %d)", eattr.counter, data->counter);
 750                 data->counter_too_small = eattr.counter;
 751                 /* Reply using Re-auth w/ AT_COUNTER_TOO_SMALL. The current
 752                  * reauth_id must not be used to start a new reauthentication.
 753                  * However, since it was used in the last EAP-Response-Identity
 754                  * packet, it has to saved for the following fullauth to be
 755                  * used in MK derivation. */
 756                 os_free(data->last_eap_identity);
 757                 data->last_eap_identity = data->reauth_id;
 758                 data->last_eap_identity_len = data->reauth_id_len;
 759                 data->reauth_id = NULL;
 760                 data->reauth_id_len = 0;
 761                 os_free(decrypted);
 762                 return eap_sim_response_reauth(data, req, respDataLen, 1);
 763         }
 764         data->counter = eattr.counter;
 765
 766         os_memcpy(data->nonce_s, eattr.nonce_s, EAP_SIM_NONCE_S_LEN);
 767         wpa_hexdump(MSG_DEBUG, "EAP-SIM: (encr) AT_NONCE_S",
 768                     data->nonce_s, EAP_SIM_NONCE_S_LEN);
 769
 770         eap_sim_derive_keys_reauth(data->counter,
 771                                    data->reauth_id, data->reauth_id_len,
 772                                    data->nonce_s, data->mk, data->msk,
 773                                    data->emsk);
 774         eap_sim_clear_identities(data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
 775         eap_sim_learn_ids(data, &eattr);
 776
 777         if (data->state != FAILURE)
 778                 data->state = SUCCESS;
 779
 780         data->num_id_req = 0;
 781         data->num_notification = 0;
 782         if (data->counter > EAP_SIM_MAX_FAST_REAUTHS) {
 783                 wpa_printf(MSG_DEBUG, "EAP-SIM: Maximum number of "
 784                            "fast reauths performed - force fullauth");
 785                 eap_sim_clear_identities(data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
 786         }
 787         os_free(decrypted);
 788         return eap_sim_response_reauth(data, req, respDataLen, 0);
 789 }
 790
 791
 792 static u8 * eap_sim_process(struct eap_sm *sm, void *priv,
 793                             struct eap_method_ret *ret,
 794                             const u8 *reqData, size_t reqDataLen,
 795                             size_t *respDataLen)
 796 {
 797         struct eap_sim_data *data = priv;
 798         const struct eap_hdr *req;
 799         u8 subtype, *res;
 800         const u8 *pos;
 801         struct eap_sim_attrs attr;
 802         size_t len;
 803
 804         wpa_hexdump(MSG_DEBUG, "EAP-SIM: EAP data", reqData, reqDataLen);
 805         if (eap_get_config_identity(sm, &len) == NULL) {
 806                 wpa_printf(MSG_INFO, "EAP-SIM: Identity not configured");
 807                 eap_sm_request_identity(sm);
 808                 ret->ignore = TRUE;
 809                 return NULL;
 810         }
 811
 812         pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SIM,
 813                                reqData, reqDataLen, &len);
 814         if (pos == NULL || len < 1) {
 815                 ret->ignore = TRUE;
 816                 return NULL;
 817         }
 818         req = (const struct eap_hdr *) reqData;
 819         len = be_to_host16(req->length);
 820
 821         ret->ignore = FALSE;
 822         ret->methodState = METHOD_MAY_CONT;
 823         ret->decision = DECISION_FAIL;
 824         ret->allowNotifications = TRUE;
 825
 826         subtype = *pos++;
 827         wpa_printf(MSG_DEBUG, "EAP-SIM: Subtype=%d", subtype);
 828         pos += 2; /* Reserved */
 829
 830         if (eap_sim_parse_attr(pos, reqData + len, &attr, 0, 0)) {
 831                 res = eap_sim_client_error(data, req, respDataLen,
 832                                            EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 833                 goto done;
 834         }
 835
 836         switch (subtype) {
 837         case EAP_SIM_SUBTYPE_START:
 838                 res = eap_sim_process_start(sm, data, req,
 839                                             respDataLen, &attr);
 840                 break;
 841         case EAP_SIM_SUBTYPE_CHALLENGE:
 842                 res = eap_sim_process_challenge(sm, data, req, len,
 843                                                 respDataLen, &attr);
 844                 break;
 845         case EAP_SIM_SUBTYPE_NOTIFICATION:
 846                 res = eap_sim_process_notification(sm, data, req, len,
 847                                                    respDataLen, &attr);
 848                 break;
 849         case EAP_SIM_SUBTYPE_REAUTHENTICATION:
 850                 res = eap_sim_process_reauthentication(sm, data, req, len,
 851                                                        respDataLen, &attr);
 852                 break;
 853         case EAP_SIM_SUBTYPE_CLIENT_ERROR:
 854                 wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Client-Error");
 855                 res = eap_sim_client_error(data, req, respDataLen,
 856                                            EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 857                 break;
 858         default:
 859                 wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown subtype=%d", subtype);
 860                 res = eap_sim_client_error(data, req, respDataLen,
 861                                            EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 862                 break;
 863         }
 864
 865 done:
 866         if (data->state == FAILURE) {
 867                 ret->decision = DECISION_FAIL;
 868                 ret->methodState = METHOD_DONE;
 869         } else if (data->state == SUCCESS) {
 870                 ret->decision = DECISION_COND_SUCC;
 871                 ret->methodState = METHOD_DONE;
 872         }
 873
 874         if (ret->methodState == METHOD_DONE) {
 875                 ret->allowNotifications = FALSE;
 876         }
 877
 878         return res;
 879 }
 880
 881
 882 static Boolean eap_sim_has_reauth_data(struct eap_sm *sm, void *priv)
 883 {
 884         struct eap_sim_data *data = priv;
 885         return data->pseudonym || data->reauth_id;
 886 }
 887
 888
 889 static void eap_sim_deinit_for_reauth(struct eap_sm *sm, void *priv)
 890 {
 891         struct eap_sim_data *data = priv;
 892         eap_sim_clear_identities(data, CLEAR_EAP_ID);
 893 }
 894
 895
 896 static void * eap_sim_init_for_reauth(struct eap_sm *sm, void *priv)
 897 {
 898         struct eap_sim_data *data = priv;
 899         if (hostapd_get_rand(data->nonce_mt, EAP_SIM_NONCE_MT_LEN)) {
 900                 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to get random data "
 901                            "for NONCE_MT");
 902                 os_free(data);
 903                 return NULL;
 904         }
 905         data->num_id_req = 0;
 906         data->num_notification = 0;
 907         data->state = CONTINUE;
 908         return priv;
 909 }
 910
 911
 912 static const u8 * eap_sim_get_identity(struct eap_sm *sm, void *priv,
 913                                        size_t *len)
 914 {
 915         struct eap_sim_data *data = priv;
 916
 917         if (data->reauth_id) {
 918                 *len = data->reauth_id_len;
 919                 return data->reauth_id;
 920         }
 921
 922         if (data->pseudonym) {
 923                 *len = data->pseudonym_len;
 924                 return data->pseudonym;
 925         }
 926
 927         return NULL;
 928 }
 929
 930
 931 static Boolean eap_sim_isKeyAvailable(struct eap_sm *sm, void *priv)
 932 {
 933         struct eap_sim_data *data = priv;
 934         return data->state == SUCCESS;
 935 }
 936
 937
 938 static u8 * eap_sim_getKey(struct eap_sm *sm, void *priv, size_t *len)
 939 {
 940         struct eap_sim_data *data = priv;
 941         u8 *key;
 942
 943         if (data->state != SUCCESS)
 944                 return NULL;
 945
 946         key = os_malloc(EAP_SIM_KEYING_DATA_LEN);
 947         if (key == NULL)
 948                 return NULL;
 949
 950         *len = EAP_SIM_KEYING_DATA_LEN;
 951         os_memcpy(key, data->msk, EAP_SIM_KEYING_DATA_LEN);
 952
 953         return key;
 954 }
 955
 956
 957 static u8 * eap_sim_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
 958 {
 959         struct eap_sim_data *data = priv;
 960         u8 *key;
 961
 962         if (data->state != SUCCESS)
 963                 return NULL;
 964
 965         key = os_malloc(EAP_EMSK_LEN);
 966         if (key == NULL)
 967                 return NULL;
 968
 969         *len = EAP_EMSK_LEN;
 970         os_memcpy(key, data->emsk, EAP_EMSK_LEN);
 971
 972         return key;
 973 }
 974
 975
 976 int eap_peer_sim_register(void)
 977 {
 978         struct eap_method *eap;
 979         int ret;
 980
 981         eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
 982                                     EAP_VENDOR_IETF, EAP_TYPE_SIM, "SIM");
 983         if (eap == NULL)
 984                 return -1;
 985
 986         eap->init = eap_sim_init;
 987         eap->deinit = eap_sim_deinit;
 988         eap->process = eap_sim_process;
 989         eap->isKeyAvailable = eap_sim_isKeyAvailable;
 990         eap->getKey = eap_sim_getKey;
 991         eap->has_reauth_data = eap_sim_has_reauth_data;
 992         eap->deinit_for_reauth = eap_sim_deinit_for_reauth;
 993         eap->init_for_reauth = eap_sim_init_for_reauth;
 994         eap->get_identity = eap_sim_get_identity;
 995         eap->get_emsk = eap_sim_get_emsk;
 996
 997         ret = eap_peer_method_register(eap);
 998         if (ret)
 999                 eap_peer_method_free(eap);
1000         return ret;
1001 }