www.project-moonshot.org Git - mech_eap.orig/blob - libeap/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 "pcsc_funcs.h"
  19 #include "crypto/milenage.h"
  20 #include "eap_peer/eap_i.h"
  21 #include "eap_config.h"
  22 #include "eap_common/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 {
  51                 CONTINUE, RESULT_SUCCESS, RESULT_FAILURE, SUCCESS, FAILURE
  52         } state;
  53         int result_ind, use_result_ind;
  54 };
  55
  56
  57 #ifndef CONFIG_NO_STDOUT_DEBUG
  58 static const char * eap_sim_state_txt(int state)
  59 {
  60         switch (state) {
  61         case CONTINUE:
  62                 return "CONTINUE";
  63         case RESULT_SUCCESS:
  64                 return "RESULT_SUCCESS";
  65         case RESULT_FAILURE:
  66                 return "RESULT_FAILURE";
  67         case SUCCESS:
  68                 return "SUCCESS";
  69         case FAILURE:
  70                 return "FAILURE";
  71         default:
  72                 return "?";
  73         }
  74 }
  75 #endif /* CONFIG_NO_STDOUT_DEBUG */
  76
  77
  78 static void eap_sim_state(struct eap_sim_data *data, int state)
  79 {
  80         wpa_printf(MSG_DEBUG, "EAP-SIM: %s -> %s",
  81                    eap_sim_state_txt(data->state),
  82                    eap_sim_state_txt(state));
  83         data->state = state;
  84 }
  85
  86
  87 static void * eap_sim_init(struct eap_sm *sm)
  88 {
  89         struct eap_sim_data *data;
  90         struct eap_peer_config *config = eap_get_config(sm);
  91
  92         data = os_zalloc(sizeof(*data));
  93         if (data == NULL)
  94                 return NULL;
  95
  96         if (os_get_random(data->nonce_mt, EAP_SIM_NONCE_MT_LEN)) {
  97                 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to get random data "
  98                            "for NONCE_MT");
  99                 os_free(data);
 100                 return NULL;
 101         }
 102
 103         data->min_num_chal = 2;
 104         if (config && config->phase1) {
 105                 char *pos = os_strstr(config->phase1, "sim_min_num_chal=");
 106                 if (pos) {
 107                         data->min_num_chal = atoi(pos + 17);
 108                         if (data->min_num_chal < 2 || data->min_num_chal > 3) {
 109                                 wpa_printf(MSG_WARNING, "EAP-SIM: Invalid "
 110                                            "sim_min_num_chal configuration "
 111                                            "(%lu, expected 2 or 3)",
 112                                            (unsigned long) data->min_num_chal);
 113                                 os_free(data);
 114                                 return NULL;
 115                         }
 116                         wpa_printf(MSG_DEBUG, "EAP-SIM: Set minimum number of "
 117                                    "challenges to %lu",
 118                                    (unsigned long) data->min_num_chal);
 119                 }
 120
 121                 data->result_ind = os_strstr(config->phase1, "result_ind=1") !=
 122                         NULL;
 123         }
 124
 125         eap_sim_state(data, CONTINUE);
 126
 127         return data;
 128 }
 129
 130
 131 static void eap_sim_deinit(struct eap_sm *sm, void *priv)
 132 {
 133         struct eap_sim_data *data = priv;
 134         if (data) {
 135                 os_free(data->ver_list);
 136                 os_free(data->pseudonym);
 137                 os_free(data->reauth_id);
 138                 os_free(data->last_eap_identity);
 139                 os_free(data);
 140         }
 141 }
 142
 143
 144 static int eap_sim_gsm_auth(struct eap_sm *sm, struct eap_sim_data *data)
 145 {
 146         struct eap_peer_config *conf;
 147
 148         wpa_printf(MSG_DEBUG, "EAP-SIM: GSM authentication algorithm");
 149
 150         conf = eap_get_config(sm);
 151         if (conf == NULL)
 152                 return -1;
 153         if (conf->pcsc) {
 154                 if (scard_gsm_auth(sm->scard_ctx, data->rand[0],
 155                                    data->sres[0], data->kc[0]) ||
 156                     scard_gsm_auth(sm->scard_ctx, data->rand[1],
 157                                    data->sres[1], data->kc[1]) ||
 158                     (data->num_chal > 2 &&
 159                      scard_gsm_auth(sm->scard_ctx, data->rand[2],
 160                                     data->sres[2], data->kc[2]))) {
 161                         wpa_printf(MSG_DEBUG, "EAP-SIM: GSM SIM "
 162                                    "authentication could not be completed");
 163                         return -1;
 164                 }
 165                 return 0;
 166         }
 167
 168 #ifdef CONFIG_SIM_SIMULATOR
 169         if (conf->password) {
 170                 u8 opc[16], k[16];
 171                 const char *pos;
 172                 size_t i;
 173                 wpa_printf(MSG_DEBUG, "EAP-SIM: Use internal GSM-Milenage "
 174                            "implementation for authentication");
 175                 if (conf->password_len < 65) {
 176                         wpa_printf(MSG_DEBUG, "EAP-SIM: invalid GSM-Milenage "
 177                                    "password");
 178                         return -1;
 179                 }
 180                 pos = (const char *) conf->password;
 181                 if (hexstr2bin(pos, k, 16))
 182                         return -1;
 183                 pos += 32;
 184                 if (*pos != ':')
 185                         return -1;
 186                 pos++;
 187
 188                 if (hexstr2bin(pos, opc, 16))
 189                         return -1;
 190
 191                 for (i = 0; i < data->num_chal; i++) {
 192                         if (gsm_milenage(opc, k, data->rand[i],
 193                                          data->sres[i], data->kc[i])) {
 194                                 wpa_printf(MSG_DEBUG, "EAP-SIM: "
 195                                            "GSM-Milenage authentication "
 196                                            "could not be completed");
 197                                 return -1;
 198                         }
 199                         wpa_hexdump(MSG_DEBUG, "EAP-SIM: RAND",
 200                                     data->rand[i], GSM_RAND_LEN);
 201                         wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: SRES",
 202                                         data->sres[i], EAP_SIM_SRES_LEN);
 203                         wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: Kc",
 204                                         data->kc[i], EAP_SIM_KC_LEN);
 205                 }
 206                 return 0;
 207         }
 208 #endif /* CONFIG_SIM_SIMULATOR */
 209
 210 #ifdef CONFIG_SIM_HARDCODED
 211         /* These hardcoded Kc and SRES values are used for testing. RAND to
 212          * KC/SREC mapping is very bogus as far as real authentication is
 213          * concerned, but it is quite useful for cases where the AS is rotating
 214          * the order of pre-configured values. */
 215         {
 216                 size_t i;
 217
 218                 wpa_printf(MSG_DEBUG, "EAP-SIM: Use hardcoded Kc and SRES "
 219                            "values for testing");
 220
 221                 for (i = 0; i < data->num_chal; i++) {
 222                         if (data->rand[i][0] == 0xaa) {
 223                                 os_memcpy(data->kc[i],
 224                                           "\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7",
 225                                           EAP_SIM_KC_LEN);
 226                                 os_memcpy(data->sres[i], "\xd1\xd2\xd3\xd4",
 227                                           EAP_SIM_SRES_LEN);
 228                         } else if (data->rand[i][0] == 0xbb) {
 229                                 os_memcpy(data->kc[i],
 230                                           "\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7",
 231                                           EAP_SIM_KC_LEN);
 232                                 os_memcpy(data->sres[i], "\xe1\xe2\xe3\xe4",
 233                                           EAP_SIM_SRES_LEN);
 234                         } else {
 235                                 os_memcpy(data->kc[i],
 236                                           "\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7",
 237                                           EAP_SIM_KC_LEN);
 238                                 os_memcpy(data->sres[i], "\xf1\xf2\xf3\xf4",
 239                                           EAP_SIM_SRES_LEN);
 240                         }
 241                 }
 242         }
 243
 244         return 0;
 245
 246 #else /* CONFIG_SIM_HARDCODED */
 247
 248         wpa_printf(MSG_DEBUG, "EAP-SIM: No GSM authentication algorithm "
 249                    "enabled");
 250         return -1;
 251
 252 #endif /* CONFIG_SIM_HARDCODED */
 253 }
 254
 255
 256 static int eap_sim_supported_ver(int version)
 257 {
 258         return version == EAP_SIM_VERSION;
 259 }
 260
 261
 262 #define CLEAR_PSEUDONYM 0x01
 263 #define CLEAR_REAUTH_ID 0x02
 264 #define CLEAR_EAP_ID    0x04
 265
 266 static void eap_sim_clear_identities(struct eap_sim_data *data, int id)
 267 {
 268         wpa_printf(MSG_DEBUG, "EAP-SIM: forgetting old%s%s%s",
 269                    id & CLEAR_PSEUDONYM ? " pseudonym" : "",
 270                    id & CLEAR_REAUTH_ID ? " reauth_id" : "",
 271                    id & CLEAR_EAP_ID ? " eap_id" : "");
 272         if (id & CLEAR_PSEUDONYM) {
 273                 os_free(data->pseudonym);
 274                 data->pseudonym = NULL;
 275                 data->pseudonym_len = 0;
 276         }
 277         if (id & CLEAR_REAUTH_ID) {
 278                 os_free(data->reauth_id);
 279                 data->reauth_id = NULL;
 280                 data->reauth_id_len = 0;
 281         }
 282         if (id & CLEAR_EAP_ID) {
 283                 os_free(data->last_eap_identity);
 284                 data->last_eap_identity = NULL;
 285                 data->last_eap_identity_len = 0;
 286         }
 287 }
 288
 289
 290 static int eap_sim_learn_ids(struct eap_sim_data *data,
 291                              struct eap_sim_attrs *attr)
 292 {
 293         if (attr->next_pseudonym) {
 294                 os_free(data->pseudonym);
 295                 data->pseudonym = os_malloc(attr->next_pseudonym_len);
 296                 if (data->pseudonym == NULL) {
 297                         wpa_printf(MSG_INFO, "EAP-SIM: (encr) No memory for "
 298                                    "next pseudonym");
 299                         return -1;
 300                 }
 301                 os_memcpy(data->pseudonym, attr->next_pseudonym,
 302                           attr->next_pseudonym_len);
 303                 data->pseudonym_len = attr->next_pseudonym_len;
 304                 wpa_hexdump_ascii(MSG_DEBUG,
 305                                   "EAP-SIM: (encr) AT_NEXT_PSEUDONYM",
 306                                   data->pseudonym,
 307                                   data->pseudonym_len);
 308         }
 309
 310         if (attr->next_reauth_id) {
 311                 os_free(data->reauth_id);
 312                 data->reauth_id = os_malloc(attr->next_reauth_id_len);
 313                 if (data->reauth_id == NULL) {
 314                         wpa_printf(MSG_INFO, "EAP-SIM: (encr) No memory for "
 315                                    "next reauth_id");
 316                         return -1;
 317                 }
 318                 os_memcpy(data->reauth_id, attr->next_reauth_id,
 319                           attr->next_reauth_id_len);
 320                 data->reauth_id_len = attr->next_reauth_id_len;
 321                 wpa_hexdump_ascii(MSG_DEBUG,
 322                                   "EAP-SIM: (encr) AT_NEXT_REAUTH_ID",
 323                                   data->reauth_id,
 324                                   data->reauth_id_len);
 325         }
 326
 327         return 0;
 328 }
 329
 330
 331 static struct wpabuf * eap_sim_client_error(struct eap_sim_data *data, u8 id,
 332                                             int err)
 333 {
 334         struct eap_sim_msg *msg;
 335
 336         eap_sim_state(data, FAILURE);
 337         data->num_id_req = 0;
 338         data->num_notification = 0;
 339
 340         msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, EAP_TYPE_SIM,
 341                                EAP_SIM_SUBTYPE_CLIENT_ERROR);
 342         eap_sim_msg_add(msg, EAP_SIM_AT_CLIENT_ERROR_CODE, err, NULL, 0);
 343         return eap_sim_msg_finish(msg, NULL, NULL, 0);
 344 }
 345
 346
 347 static struct wpabuf * eap_sim_response_start(struct eap_sm *sm,
 348                                               struct eap_sim_data *data, u8 id,
 349                                               enum eap_sim_id_req id_req)
 350 {
 351         const u8 *identity = NULL;
 352         size_t identity_len = 0;
 353         struct eap_sim_msg *msg;
 354
 355         data->reauth = 0;
 356         if (id_req == ANY_ID && data->reauth_id) {
 357                 identity = data->reauth_id;
 358                 identity_len = data->reauth_id_len;
 359                 data->reauth = 1;
 360         } else if ((id_req == ANY_ID || id_req == FULLAUTH_ID) &&
 361                    data->pseudonym) {
 362                 identity = data->pseudonym;
 363                 identity_len = data->pseudonym_len;
 364                 eap_sim_clear_identities(data, CLEAR_REAUTH_ID);
 365         } else if (id_req != NO_ID_REQ) {
 366                 identity = eap_get_config_identity(sm, &identity_len);
 367                 if (identity) {
 368                         eap_sim_clear_identities(data, CLEAR_PSEUDONYM |
 369                                                  CLEAR_REAUTH_ID);
 370                 }
 371         }
 372         if (id_req != NO_ID_REQ)
 373                 eap_sim_clear_identities(data, CLEAR_EAP_ID);
 374
 375         wpa_printf(MSG_DEBUG, "Generating EAP-SIM Start (id=%d)", id);
 376         msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id,
 377                                EAP_TYPE_SIM, EAP_SIM_SUBTYPE_START);
 378         if (!data->reauth) {
 379                 wpa_hexdump(MSG_DEBUG, "   AT_NONCE_MT",
 380                             data->nonce_mt, EAP_SIM_NONCE_MT_LEN);
 381                 eap_sim_msg_add(msg, EAP_SIM_AT_NONCE_MT, 0,
 382                                 data->nonce_mt, EAP_SIM_NONCE_MT_LEN);
 383                 wpa_printf(MSG_DEBUG, "   AT_SELECTED_VERSION %d",
 384                            data->selected_version);
 385                 eap_sim_msg_add(msg, EAP_SIM_AT_SELECTED_VERSION,
 386                                 data->selected_version, NULL, 0);
 387         }
 388
 389         if (identity) {
 390                 wpa_hexdump_ascii(MSG_DEBUG, "   AT_IDENTITY",
 391                                   identity, identity_len);
 392                 eap_sim_msg_add(msg, EAP_SIM_AT_IDENTITY, identity_len,
 393                                 identity, identity_len);
 394         }
 395
 396         return eap_sim_msg_finish(msg, NULL, NULL, 0);
 397 }
 398
 399
 400 static struct wpabuf * eap_sim_response_challenge(struct eap_sim_data *data,
 401                                                   u8 id)
 402 {
 403         struct eap_sim_msg *msg;
 404
 405         wpa_printf(MSG_DEBUG, "Generating EAP-SIM Challenge (id=%d)", id);
 406         msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, EAP_TYPE_SIM,
 407                                EAP_SIM_SUBTYPE_CHALLENGE);
 408         if (data->use_result_ind) {
 409                 wpa_printf(MSG_DEBUG, "   AT_RESULT_IND");
 410                 eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0);
 411         }
 412         wpa_printf(MSG_DEBUG, "   AT_MAC");
 413         eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
 414         return eap_sim_msg_finish(msg, data->k_aut, (u8 *) data->sres,
 415                                   data->num_chal * EAP_SIM_SRES_LEN);
 416 }
 417
 418
 419 static struct wpabuf * eap_sim_response_reauth(struct eap_sim_data *data,
 420                                                u8 id, int counter_too_small)
 421 {
 422         struct eap_sim_msg *msg;
 423         unsigned int counter;
 424
 425         wpa_printf(MSG_DEBUG, "Generating EAP-SIM Reauthentication (id=%d)",
 426                    id);
 427         msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, EAP_TYPE_SIM,
 428                                EAP_SIM_SUBTYPE_REAUTHENTICATION);
 429         wpa_printf(MSG_DEBUG, "   AT_IV");
 430         wpa_printf(MSG_DEBUG, "   AT_ENCR_DATA");
 431         eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV, EAP_SIM_AT_ENCR_DATA);
 432
 433         if (counter_too_small) {
 434                 wpa_printf(MSG_DEBUG, "   *AT_COUNTER_TOO_SMALL");
 435                 eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER_TOO_SMALL, 0, NULL, 0);
 436                 counter = data->counter_too_small;
 437         } else
 438                 counter = data->counter;
 439
 440         wpa_printf(MSG_DEBUG, "   *AT_COUNTER %d", counter);
 441         eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, counter, NULL, 0);
 442
 443         if (eap_sim_msg_add_encr_end(msg, data->k_encr, EAP_SIM_AT_PADDING)) {
 444                 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to encrypt "
 445                            "AT_ENCR_DATA");
 446                 eap_sim_msg_free(msg);
 447                 return NULL;
 448         }
 449         if (data->use_result_ind) {
 450                 wpa_printf(MSG_DEBUG, "   AT_RESULT_IND");
 451                 eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0);
 452         }
 453         wpa_printf(MSG_DEBUG, "   AT_MAC");
 454         eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
 455         return eap_sim_msg_finish(msg, data->k_aut, data->nonce_s,
 456                                   EAP_SIM_NONCE_S_LEN);
 457 }
 458
 459
 460 static struct wpabuf * eap_sim_response_notification(struct eap_sim_data *data,
 461                                                      u8 id, u16 notification)
 462 {
 463         struct eap_sim_msg *msg;
 464         u8 *k_aut = (notification & 0x4000) == 0 ? data->k_aut : NULL;
 465
 466         wpa_printf(MSG_DEBUG, "Generating EAP-SIM Notification (id=%d)", id);
 467         msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id,
 468                                EAP_TYPE_SIM, EAP_SIM_SUBTYPE_NOTIFICATION);
 469         if (k_aut && data->reauth) {
 470                 wpa_printf(MSG_DEBUG, "   AT_IV");
 471                 wpa_printf(MSG_DEBUG, "   AT_ENCR_DATA");
 472                 eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV,
 473                                            EAP_SIM_AT_ENCR_DATA);
 474                 wpa_printf(MSG_DEBUG, "   *AT_COUNTER %d", data->counter);
 475                 eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, data->counter,
 476                                 NULL, 0);
 477                 if (eap_sim_msg_add_encr_end(msg, data->k_encr,
 478                                              EAP_SIM_AT_PADDING)) {
 479                         wpa_printf(MSG_WARNING, "EAP-SIM: Failed to encrypt "
 480                                    "AT_ENCR_DATA");
 481                         eap_sim_msg_free(msg);
 482                         return NULL;
 483                 }
 484         }
 485         if (k_aut) {
 486                 wpa_printf(MSG_DEBUG, "   AT_MAC");
 487                 eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
 488         }
 489         return eap_sim_msg_finish(msg, k_aut, (u8 *) "", 0);
 490 }
 491
 492
 493 static struct wpabuf * eap_sim_process_start(struct eap_sm *sm,
 494                                              struct eap_sim_data *data, u8 id,
 495                                              struct eap_sim_attrs *attr)
 496 {
 497         int selected_version = -1, id_error;
 498         size_t i;
 499         u8 *pos;
 500
 501         wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Start");
 502         if (attr->version_list == NULL) {
 503                 wpa_printf(MSG_INFO, "EAP-SIM: No AT_VERSION_LIST in "
 504                            "SIM/Start");
 505                 return eap_sim_client_error(data, id,
 506                                             EAP_SIM_UNSUPPORTED_VERSION);
 507         }
 508
 509         os_free(data->ver_list);
 510         data->ver_list = os_malloc(attr->version_list_len);
 511         if (data->ver_list == NULL) {
 512                 wpa_printf(MSG_DEBUG, "EAP-SIM: Failed to allocate "
 513                            "memory for version list");
 514                 return eap_sim_client_error(data, id,
 515                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 516         }
 517         os_memcpy(data->ver_list, attr->version_list, attr->version_list_len);
 518         data->ver_list_len = attr->version_list_len;
 519         pos = data->ver_list;
 520         for (i = 0; i < data->ver_list_len / 2; i++) {
 521                 int ver = pos[0] * 256 + pos[1];
 522                 pos += 2;
 523                 if (eap_sim_supported_ver(ver)) {
 524                         selected_version = ver;
 525                         break;
 526                 }
 527         }
 528         if (selected_version < 0) {
 529                 wpa_printf(MSG_INFO, "EAP-SIM: Could not find a supported "
 530                            "version");
 531                 return eap_sim_client_error(data, id,
 532                                             EAP_SIM_UNSUPPORTED_VERSION);
 533         }
 534         wpa_printf(MSG_DEBUG, "EAP-SIM: Selected Version %d",
 535                    selected_version);
 536         data->selected_version = selected_version;
 537
 538         id_error = 0;
 539         switch (attr->id_req) {
 540         case NO_ID_REQ:
 541                 break;
 542         case ANY_ID:
 543                 if (data->num_id_req > 0)
 544                         id_error++;
 545                 data->num_id_req++;
 546                 break;
 547         case FULLAUTH_ID:
 548                 if (data->num_id_req > 1)
 549                         id_error++;
 550                 data->num_id_req++;
 551                 break;
 552         case PERMANENT_ID:
 553                 if (data->num_id_req > 2)
 554                         id_error++;
 555                 data->num_id_req++;
 556                 break;
 557         }
 558         if (id_error) {
 559                 wpa_printf(MSG_INFO, "EAP-SIM: Too many ID requests "
 560                            "used within one authentication");
 561                 return eap_sim_client_error(data, id,
 562                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 563         }
 564
 565         return eap_sim_response_start(sm, data, id, attr->id_req);
 566 }
 567
 568
 569 static struct wpabuf * eap_sim_process_challenge(struct eap_sm *sm,
 570                                                  struct eap_sim_data *data,
 571                                                  u8 id,
 572                                                  const struct wpabuf *reqData,
 573                                                  struct eap_sim_attrs *attr)
 574 {
 575         const u8 *identity;
 576         size_t identity_len;
 577         struct eap_sim_attrs eattr;
 578
 579         wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Challenge");
 580         data->reauth = 0;
 581         if (!attr->mac || !attr->rand) {
 582                 wpa_printf(MSG_WARNING, "EAP-SIM: Challenge message "
 583                            "did not include%s%s",
 584                            !attr->mac ? " AT_MAC" : "",
 585                            !attr->rand ? " AT_RAND" : "");
 586                 return eap_sim_client_error(data, id,
 587                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 588         }
 589
 590         wpa_printf(MSG_DEBUG, "EAP-SIM: %lu challenges",
 591                    (unsigned long) attr->num_chal);
 592         if (attr->num_chal < data->min_num_chal) {
 593                 wpa_printf(MSG_INFO, "EAP-SIM: Insufficient number of "
 594                            "challenges (%lu)", (unsigned long) attr->num_chal);
 595                 return eap_sim_client_error(data, id,
 596                                             EAP_SIM_INSUFFICIENT_NUM_OF_CHAL);
 597         }
 598         if (attr->num_chal > 3) {
 599                 wpa_printf(MSG_INFO, "EAP-SIM: Too many challenges "
 600                            "(%lu)", (unsigned long) attr->num_chal);
 601                 return eap_sim_client_error(data, id,
 602                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 603         }
 604
 605         /* Verify that RANDs are different */
 606         if (os_memcmp(attr->rand, attr->rand + GSM_RAND_LEN,
 607                    GSM_RAND_LEN) == 0 ||
 608             (attr->num_chal > 2 &&
 609              (os_memcmp(attr->rand, attr->rand + 2 * GSM_RAND_LEN,
 610                         GSM_RAND_LEN) == 0 ||
 611               os_memcmp(attr->rand + GSM_RAND_LEN,
 612                         attr->rand + 2 * GSM_RAND_LEN,
 613                         GSM_RAND_LEN) == 0))) {
 614                 wpa_printf(MSG_INFO, "EAP-SIM: Same RAND used multiple times");
 615                 return eap_sim_client_error(data, id,
 616                                             EAP_SIM_RAND_NOT_FRESH);
 617         }
 618
 619         os_memcpy(data->rand, attr->rand, attr->num_chal * GSM_RAND_LEN);
 620         data->num_chal = attr->num_chal;
 621
 622         if (eap_sim_gsm_auth(sm, data)) {
 623                 wpa_printf(MSG_WARNING, "EAP-SIM: GSM authentication failed");
 624                 return eap_sim_client_error(data, id,
 625                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 626         }
 627         if (data->last_eap_identity) {
 628                 identity = data->last_eap_identity;
 629                 identity_len = data->last_eap_identity_len;
 630         } else if (data->pseudonym) {
 631                 identity = data->pseudonym;
 632                 identity_len = data->pseudonym_len;
 633         } else
 634                 identity = eap_get_config_identity(sm, &identity_len);
 635         wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Selected identity for MK "
 636                           "derivation", identity, identity_len);
 637         eap_sim_derive_mk(identity, identity_len, data->nonce_mt,
 638                           data->selected_version, data->ver_list,
 639                           data->ver_list_len, data->num_chal,
 640                           (const u8 *) data->kc, data->mk);
 641         eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut, data->msk,
 642                             data->emsk);
 643         if (eap_sim_verify_mac(data->k_aut, reqData, attr->mac, data->nonce_mt,
 644                                EAP_SIM_NONCE_MT_LEN)) {
 645                 wpa_printf(MSG_WARNING, "EAP-SIM: Challenge message "
 646                            "used invalid AT_MAC");
 647                 return eap_sim_client_error(data, id,
 648                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 649         }
 650
 651         /* Old reauthentication and pseudonym identities must not be used
 652          * anymore. In other words, if no new identities are received, full
 653          * authentication will be used on next reauthentication. */
 654         eap_sim_clear_identities(data, CLEAR_PSEUDONYM | CLEAR_REAUTH_ID |
 655                                  CLEAR_EAP_ID);
 656
 657         if (attr->encr_data) {
 658                 u8 *decrypted;
 659                 decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
 660                                                attr->encr_data_len, attr->iv,
 661                                                &eattr, 0);
 662                 if (decrypted == NULL) {
 663                         return eap_sim_client_error(
 664                                 data, id, EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 665                 }
 666                 eap_sim_learn_ids(data, &eattr);
 667                 os_free(decrypted);
 668         }
 669
 670         if (data->result_ind && attr->result_ind)
 671                 data->use_result_ind = 1;
 672
 673         if (data->state != FAILURE && data->state != RESULT_FAILURE) {
 674                 eap_sim_state(data, data->use_result_ind ?
 675                               RESULT_SUCCESS : SUCCESS);
 676         }
 677
 678         data->num_id_req = 0;
 679         data->num_notification = 0;
 680         /* RFC 4186 specifies that counter is initialized to one after
 681          * fullauth, but initializing it to zero makes it easier to implement
 682          * reauth verification. */
 683         data->counter = 0;
 684         return eap_sim_response_challenge(data, id);
 685 }
 686
 687
 688 static int eap_sim_process_notification_reauth(struct eap_sim_data *data,
 689                                                struct eap_sim_attrs *attr)
 690 {
 691         struct eap_sim_attrs eattr;
 692         u8 *decrypted;
 693
 694         if (attr->encr_data == NULL || attr->iv == NULL) {
 695                 wpa_printf(MSG_WARNING, "EAP-SIM: Notification message after "
 696                            "reauth did not include encrypted data");
 697                 return -1;
 698         }
 699
 700         decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
 701                                        attr->encr_data_len, attr->iv, &eattr,
 702                                        0);
 703         if (decrypted == NULL) {
 704                 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to parse encrypted "
 705                            "data from notification message");
 706                 return -1;
 707         }
 708
 709         if (eattr.counter < 0 || (size_t) eattr.counter != data->counter) {
 710                 wpa_printf(MSG_WARNING, "EAP-SIM: Counter in notification "
 711                            "message does not match with counter in reauth "
 712                            "message");
 713                 os_free(decrypted);
 714                 return -1;
 715         }
 716
 717         os_free(decrypted);
 718         return 0;
 719 }
 720
 721
 722 static int eap_sim_process_notification_auth(struct eap_sim_data *data,
 723                                              const struct wpabuf *reqData,
 724                                              struct eap_sim_attrs *attr)
 725 {
 726         if (attr->mac == NULL) {
 727                 wpa_printf(MSG_INFO, "EAP-SIM: no AT_MAC in after_auth "
 728                            "Notification message");
 729                 return -1;
 730         }
 731
 732         if (eap_sim_verify_mac(data->k_aut, reqData, attr->mac, (u8 *) "", 0))
 733         {
 734                 wpa_printf(MSG_WARNING, "EAP-SIM: Notification message "
 735                            "used invalid AT_MAC");
 736                 return -1;
 737         }
 738
 739         if (data->reauth &&
 740             eap_sim_process_notification_reauth(data, attr)) {
 741                 wpa_printf(MSG_WARNING, "EAP-SIM: Invalid notification "
 742                            "message after reauth");
 743                 return -1;
 744         }
 745
 746         return 0;
 747 }
 748
 749
 750 static struct wpabuf * eap_sim_process_notification(
 751         struct eap_sm *sm, struct eap_sim_data *data, u8 id,
 752         const struct wpabuf *reqData, struct eap_sim_attrs *attr)
 753 {
 754         wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Notification");
 755         if (data->num_notification > 0) {
 756                 wpa_printf(MSG_INFO, "EAP-SIM: too many notification "
 757                            "rounds (only one allowed)");
 758                 return eap_sim_client_error(data, id,
 759                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 760         }
 761         data->num_notification++;
 762         if (attr->notification == -1) {
 763                 wpa_printf(MSG_INFO, "EAP-SIM: no AT_NOTIFICATION in "
 764                            "Notification message");
 765                 return eap_sim_client_error(data, id,
 766                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 767         }
 768
 769         if ((attr->notification & 0x4000) == 0 &&
 770             eap_sim_process_notification_auth(data, reqData, attr)) {
 771                 return eap_sim_client_error(data, id,
 772                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 773         }
 774
 775         eap_sim_report_notification(sm->msg_ctx, attr->notification, 0);
 776         if (attr->notification >= 0 && attr->notification < 32768) {
 777                 eap_sim_state(data, FAILURE);
 778         } else if (attr->notification == EAP_SIM_SUCCESS &&
 779                    data->state == RESULT_SUCCESS)
 780                 eap_sim_state(data, SUCCESS);
 781         return eap_sim_response_notification(data, id, attr->notification);
 782 }
 783
 784
 785 static struct wpabuf * eap_sim_process_reauthentication(
 786         struct eap_sm *sm, struct eap_sim_data *data, u8 id,
 787         const struct wpabuf *reqData, struct eap_sim_attrs *attr)
 788 {
 789         struct eap_sim_attrs eattr;
 790         u8 *decrypted;
 791
 792         wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Reauthentication");
 793
 794         if (data->reauth_id == NULL) {
 795                 wpa_printf(MSG_WARNING, "EAP-SIM: Server is trying "
 796                            "reauthentication, but no reauth_id available");
 797                 return eap_sim_client_error(data, id,
 798                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 799         }
 800
 801         data->reauth = 1;
 802         if (eap_sim_verify_mac(data->k_aut, reqData, attr->mac, (u8 *) "", 0))
 803         {
 804                 wpa_printf(MSG_WARNING, "EAP-SIM: Reauthentication "
 805                            "did not have valid AT_MAC");
 806                 return eap_sim_client_error(data, id,
 807                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 808         }
 809
 810         if (attr->encr_data == NULL || attr->iv == NULL) {
 811                 wpa_printf(MSG_WARNING, "EAP-SIM: Reauthentication "
 812                            "message did not include encrypted data");
 813                 return eap_sim_client_error(data, id,
 814                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 815         }
 816
 817         decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
 818                                        attr->encr_data_len, attr->iv, &eattr,
 819                                        0);
 820         if (decrypted == NULL) {
 821                 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to parse encrypted "
 822                            "data from reauthentication message");
 823                 return eap_sim_client_error(data, id,
 824                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 825         }
 826
 827         if (eattr.nonce_s == NULL || eattr.counter < 0) {
 828                 wpa_printf(MSG_INFO, "EAP-SIM: (encr) No%s%s in reauth packet",
 829                            !eattr.nonce_s ? " AT_NONCE_S" : "",
 830                            eattr.counter < 0 ? " AT_COUNTER" : "");
 831                 os_free(decrypted);
 832                 return eap_sim_client_error(data, id,
 833                                             EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 834         }
 835
 836         if (eattr.counter < 0 || (size_t) eattr.counter <= data->counter) {
 837                 wpa_printf(MSG_INFO, "EAP-SIM: (encr) Invalid counter "
 838                            "(%d <= %d)", eattr.counter, data->counter);
 839                 data->counter_too_small = eattr.counter;
 840                 /* Reply using Re-auth w/ AT_COUNTER_TOO_SMALL. The current
 841                  * reauth_id must not be used to start a new reauthentication.
 842                  * However, since it was used in the last EAP-Response-Identity
 843                  * packet, it has to saved for the following fullauth to be
 844                  * used in MK derivation. */
 845                 os_free(data->last_eap_identity);
 846                 data->last_eap_identity = data->reauth_id;
 847                 data->last_eap_identity_len = data->reauth_id_len;
 848                 data->reauth_id = NULL;
 849                 data->reauth_id_len = 0;
 850                 os_free(decrypted);
 851                 return eap_sim_response_reauth(data, id, 1);
 852         }
 853         data->counter = eattr.counter;
 854
 855         os_memcpy(data->nonce_s, eattr.nonce_s, EAP_SIM_NONCE_S_LEN);
 856         wpa_hexdump(MSG_DEBUG, "EAP-SIM: (encr) AT_NONCE_S",
 857                     data->nonce_s, EAP_SIM_NONCE_S_LEN);
 858
 859         eap_sim_derive_keys_reauth(data->counter,
 860                                    data->reauth_id, data->reauth_id_len,
 861                                    data->nonce_s, data->mk, data->msk,
 862                                    data->emsk);
 863         eap_sim_clear_identities(data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
 864         eap_sim_learn_ids(data, &eattr);
 865
 866         if (data->result_ind && attr->result_ind)
 867                 data->use_result_ind = 1;
 868
 869         if (data->state != FAILURE && data->state != RESULT_FAILURE) {
 870                 eap_sim_state(data, data->use_result_ind ?
 871                               RESULT_SUCCESS : SUCCESS);
 872         }
 873
 874         data->num_id_req = 0;
 875         data->num_notification = 0;
 876         if (data->counter > EAP_SIM_MAX_FAST_REAUTHS) {
 877                 wpa_printf(MSG_DEBUG, "EAP-SIM: Maximum number of "
 878                            "fast reauths performed - force fullauth");
 879                 eap_sim_clear_identities(data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
 880         }
 881         os_free(decrypted);
 882         return eap_sim_response_reauth(data, id, 0);
 883 }
 884
 885
 886 static struct wpabuf * eap_sim_process(struct eap_sm *sm, void *priv,
 887                                        struct eap_method_ret *ret,
 888                                        const struct wpabuf *reqData)
 889 {
 890         struct eap_sim_data *data = priv;
 891         const struct eap_hdr *req;
 892         u8 subtype, id;
 893         struct wpabuf *res;
 894         const u8 *pos;
 895         struct eap_sim_attrs attr;
 896         size_t len;
 897
 898         wpa_hexdump_buf(MSG_DEBUG, "EAP-SIM: EAP data", reqData);
 899         if (eap_get_config_identity(sm, &len) == NULL) {
 900                 wpa_printf(MSG_INFO, "EAP-SIM: Identity not configured");
 901                 eap_sm_request_identity(sm);
 902                 ret->ignore = TRUE;
 903                 return NULL;
 904         }
 905
 906         pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SIM, reqData, &len);
 907         if (pos == NULL || len < 1) {
 908                 ret->ignore = TRUE;
 909                 return NULL;
 910         }
 911         req = wpabuf_head(reqData);
 912         id = req->identifier;
 913         len = be_to_host16(req->length);
 914
 915         ret->ignore = FALSE;
 916         ret->methodState = METHOD_MAY_CONT;
 917         ret->decision = DECISION_FAIL;
 918         ret->allowNotifications = TRUE;
 919
 920         subtype = *pos++;
 921         wpa_printf(MSG_DEBUG, "EAP-SIM: Subtype=%d", subtype);
 922         pos += 2; /* Reserved */
 923
 924         if (eap_sim_parse_attr(pos, wpabuf_head_u8(reqData) + len, &attr, 0,
 925                                0)) {
 926                 res = eap_sim_client_error(data, id,
 927                                            EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 928                 goto done;
 929         }
 930
 931         switch (subtype) {
 932         case EAP_SIM_SUBTYPE_START:
 933                 res = eap_sim_process_start(sm, data, id, &attr);
 934                 break;
 935         case EAP_SIM_SUBTYPE_CHALLENGE:
 936                 res = eap_sim_process_challenge(sm, data, id, reqData, &attr);
 937                 break;
 938         case EAP_SIM_SUBTYPE_NOTIFICATION:
 939                 res = eap_sim_process_notification(sm, data, id, reqData,
 940                                                    &attr);
 941                 break;
 942         case EAP_SIM_SUBTYPE_REAUTHENTICATION:
 943                 res = eap_sim_process_reauthentication(sm, data, id, reqData,
 944                                                        &attr);
 945                 break;
 946         case EAP_SIM_SUBTYPE_CLIENT_ERROR:
 947                 wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Client-Error");
 948                 res = eap_sim_client_error(data, id,
 949                                            EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 950                 break;
 951         default:
 952                 wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown subtype=%d", subtype);
 953                 res = eap_sim_client_error(data, id,
 954                                            EAP_SIM_UNABLE_TO_PROCESS_PACKET);
 955                 break;
 956         }
 957
 958 done:
 959         if (data->state == FAILURE) {
 960                 ret->decision = DECISION_FAIL;
 961                 ret->methodState = METHOD_DONE;
 962         } else if (data->state == SUCCESS) {
 963                 ret->decision = data->use_result_ind ?
 964                         DECISION_UNCOND_SUCC : DECISION_COND_SUCC;
 965                 ret->methodState = data->use_result_ind ?
 966                         METHOD_DONE : METHOD_MAY_CONT;
 967         } else if (data->state == RESULT_FAILURE)
 968                 ret->methodState = METHOD_CONT;
 969         else if (data->state == RESULT_SUCCESS)
 970                 ret->methodState = METHOD_CONT;
 971
 972         if (ret->methodState == METHOD_DONE) {
 973                 ret->allowNotifications = FALSE;
 974         }
 975
 976         return res;
 977 }
 978
 979
 980 static Boolean eap_sim_has_reauth_data(struct eap_sm *sm, void *priv)
 981 {
 982         struct eap_sim_data *data = priv;
 983         return data->pseudonym || data->reauth_id;
 984 }
 985
 986
 987 static void eap_sim_deinit_for_reauth(struct eap_sm *sm, void *priv)
 988 {
 989         struct eap_sim_data *data = priv;
 990         eap_sim_clear_identities(data, CLEAR_EAP_ID);
 991         data->use_result_ind = 0;
 992 }
 993
 994
 995 static void * eap_sim_init_for_reauth(struct eap_sm *sm, void *priv)
 996 {
 997         struct eap_sim_data *data = priv;
 998         if (os_get_random(data->nonce_mt, EAP_SIM_NONCE_MT_LEN)) {
 999                 wpa_printf(MSG_WARNING, "EAP-SIM: Failed to get random data "
1000                            "for NONCE_MT");
1001                 os_free(data);
1002                 return NULL;
1003         }
1004         data->num_id_req = 0;
1005         data->num_notification = 0;
1006         eap_sim_state(data, CONTINUE);
1007         return priv;
1008 }
1009
1010
1011 static const u8 * eap_sim_get_identity(struct eap_sm *sm, void *priv,
1012                                        size_t *len)
1013 {
1014         struct eap_sim_data *data = priv;
1015
1016         if (data->reauth_id) {
1017                 *len = data->reauth_id_len;
1018                 return data->reauth_id;
1019         }
1020
1021         if (data->pseudonym) {
1022                 *len = data->pseudonym_len;
1023                 return data->pseudonym;
1024         }
1025
1026         return NULL;
1027 }
1028
1029
1030 static Boolean eap_sim_isKeyAvailable(struct eap_sm *sm, void *priv)
1031 {
1032         struct eap_sim_data *data = priv;
1033         return data->state == SUCCESS;
1034 }
1035
1036
1037 static u8 * eap_sim_getKey(struct eap_sm *sm, void *priv, size_t *len)
1038 {
1039         struct eap_sim_data *data = priv;
1040         u8 *key;
1041
1042         if (data->state != SUCCESS)
1043                 return NULL;
1044
1045         key = os_malloc(EAP_SIM_KEYING_DATA_LEN);
1046         if (key == NULL)
1047                 return NULL;
1048
1049         *len = EAP_SIM_KEYING_DATA_LEN;
1050         os_memcpy(key, data->msk, EAP_SIM_KEYING_DATA_LEN);
1051
1052         return key;
1053 }
1054
1055
1056 static u8 * eap_sim_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
1057 {
1058         struct eap_sim_data *data = priv;
1059         u8 *key;
1060
1061         if (data->state != SUCCESS)
1062                 return NULL;
1063
1064         key = os_malloc(EAP_EMSK_LEN);
1065         if (key == NULL)
1066                 return NULL;
1067
1068         *len = EAP_EMSK_LEN;
1069         os_memcpy(key, data->emsk, EAP_EMSK_LEN);
1070
1071         return key;
1072 }
1073
1074
1075 int eap_peer_sim_register(void)
1076 {
1077         struct eap_method *eap;
1078         int ret;
1079
1080         eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
1081                                     EAP_VENDOR_IETF, EAP_TYPE_SIM, "SIM");
1082         if (eap == NULL)
1083                 return -1;
1084
1085         eap->init = eap_sim_init;
1086         eap->deinit = eap_sim_deinit;
1087         eap->process = eap_sim_process;
1088         eap->isKeyAvailable = eap_sim_isKeyAvailable;
1089         eap->getKey = eap_sim_getKey;
1090         eap->has_reauth_data = eap_sim_has_reauth_data;
1091         eap->deinit_for_reauth = eap_sim_deinit_for_reauth;
1092         eap->init_for_reauth = eap_sim_init_for_reauth;
1093         eap->get_identity = eap_sim_get_identity;
1094         eap->get_emsk = eap_sim_get_emsk;
1095
1096         ret = eap_peer_method_register(eap);
1097         if (ret)
1098                 eap_peer_method_free(eap);
1099         return ret;
1100 }