contrib/wpa_supplicant-0.5.8/eap_aka.c

   1 /*
   2  * EAP peer method: EAP-AKA (RFC 4187)
   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 "crypto.h"
  20 #include "pcsc_funcs.h"
  21 #include "eap_sim_common.h"
  22
  23
  24 struct eap_aka_data {
  25         u8 ik[EAP_AKA_IK_LEN], ck[EAP_AKA_CK_LEN], res[EAP_AKA_RES_MAX_LEN];
  26         size_t res_len;
  27         u8 nonce_s[EAP_SIM_NONCE_S_LEN];
  28         u8 mk[EAP_SIM_MK_LEN];
  29         u8 k_aut[EAP_SIM_K_AUT_LEN];
  30         u8 k_encr[EAP_SIM_K_ENCR_LEN];
  31         u8 msk[EAP_SIM_KEYING_DATA_LEN];
  32         u8 emsk[EAP_EMSK_LEN];
  33         u8 rand[EAP_AKA_RAND_LEN], autn[EAP_AKA_AUTN_LEN];
  34         u8 auts[EAP_AKA_AUTS_LEN];
  35
  36         int num_id_req, num_notification;
  37         u8 *pseudonym;
  38         size_t pseudonym_len;
  39         u8 *reauth_id;
  40         size_t reauth_id_len;
  41         int reauth;
  42         unsigned int counter, counter_too_small;
  43         u8 *last_eap_identity;
  44         size_t last_eap_identity_len;
  45         enum { CONTINUE, SUCCESS, FAILURE } state;
  46 };
  47
  48
  49 static void * eap_aka_init(struct eap_sm *sm)
  50 {
  51         struct eap_aka_data *data;
  52         data = os_zalloc(sizeof(*data));
  53         if (data == NULL)
  54                 return NULL;
  55
  56         data->state = CONTINUE;
  57
  58         return data;
  59 }
  60
  61
  62 static void eap_aka_deinit(struct eap_sm *sm, void *priv)
  63 {
  64         struct eap_aka_data *data = priv;
  65         if (data) {
  66                 os_free(data->pseudonym);
  67                 os_free(data->reauth_id);
  68                 os_free(data->last_eap_identity);
  69                 os_free(data);
  70         }
  71 }
  72
  73
  74 static int eap_aka_umts_auth(struct eap_sm *sm, struct eap_aka_data *data)
  75 {
  76         wpa_printf(MSG_DEBUG, "EAP-AKA: UMTS authentication algorithm");
  77 #ifdef PCSC_FUNCS
  78         return scard_umts_auth(sm->scard_ctx, data->rand,
  79                                data->autn, data->res, &data->res_len,
  80                                data->ik, data->ck, data->auts);
  81 #else /* PCSC_FUNCS */
  82         /* These hardcoded Kc and SRES values are used for testing.
  83          * Could consider making them configurable. */
  84         os_memset(data->res, '2', EAP_AKA_RES_MAX_LEN);
  85         data->res_len = EAP_AKA_RES_MAX_LEN;
  86         os_memset(data->ik, '3', EAP_AKA_IK_LEN);
  87         os_memset(data->ck, '4', EAP_AKA_CK_LEN);
  88         {
  89                 u8 autn[EAP_AKA_AUTN_LEN];
  90                 os_memset(autn, '1', EAP_AKA_AUTN_LEN);
  91                 if (os_memcmp(autn, data->autn, EAP_AKA_AUTN_LEN) != 0) {
  92                         wpa_printf(MSG_WARNING, "EAP-AKA: AUTN did not match "
  93                                    "with expected value");
  94                         return -1;
  95                 }
  96         }
  97 #if 0
  98         {
  99                 static int test_resync = 1;
 100                 if (test_resync) {
 101                         /* Test Resynchronization */
 102                         test_resync = 0;
 103                         return -2;
 104                 }
 105         }
 106 #endif
 107         return 0;
 108 #endif /* PCSC_FUNCS */
 109 }
 110
 111
 112 #define CLEAR_PSEUDONYM 0x01
 113 #define CLEAR_REAUTH_ID 0x02
 114 #define CLEAR_EAP_ID    0x04
 115
 116 static void eap_aka_clear_identities(struct eap_aka_data *data, int id)
 117 {
 118         wpa_printf(MSG_DEBUG, "EAP-AKA: forgetting old%s%s%s",
 119                    id & CLEAR_PSEUDONYM ? " pseudonym" : "",
 120                    id & CLEAR_REAUTH_ID ? " reauth_id" : "",
 121                    id & CLEAR_EAP_ID ? " eap_id" : "");
 122         if (id & CLEAR_PSEUDONYM) {
 123                 os_free(data->pseudonym);
 124                 data->pseudonym = NULL;
 125                 data->pseudonym_len = 0;
 126         }
 127         if (id & CLEAR_REAUTH_ID) {
 128                 os_free(data->reauth_id);
 129                 data->reauth_id = NULL;
 130                 data->reauth_id_len = 0;
 131         }
 132         if (id & CLEAR_EAP_ID) {
 133                 os_free(data->last_eap_identity);
 134                 data->last_eap_identity = NULL;
 135                 data->last_eap_identity_len = 0;
 136         }
 137 }
 138
 139
 140 static int eap_aka_learn_ids(struct eap_aka_data *data,
 141                              struct eap_sim_attrs *attr)
 142 {
 143         if (attr->next_pseudonym) {
 144                 os_free(data->pseudonym);
 145                 data->pseudonym = os_malloc(attr->next_pseudonym_len);
 146                 if (data->pseudonym == NULL) {
 147                         wpa_printf(MSG_INFO, "EAP-AKA: (encr) No memory for "
 148                                    "next pseudonym");
 149                         return -1;
 150                 }
 151                 os_memcpy(data->pseudonym, attr->next_pseudonym,
 152                           attr->next_pseudonym_len);
 153                 data->pseudonym_len = attr->next_pseudonym_len;
 154                 wpa_hexdump_ascii(MSG_DEBUG,
 155                                   "EAP-AKA: (encr) AT_NEXT_PSEUDONYM",
 156                                   data->pseudonym,
 157                                   data->pseudonym_len);
 158         }
 159
 160         if (attr->next_reauth_id) {
 161                 os_free(data->reauth_id);
 162                 data->reauth_id = os_malloc(attr->next_reauth_id_len);
 163                 if (data->reauth_id == NULL) {
 164                         wpa_printf(MSG_INFO, "EAP-AKA: (encr) No memory for "
 165                                    "next reauth_id");
 166                         return -1;
 167                 }
 168                 os_memcpy(data->reauth_id, attr->next_reauth_id,
 169                           attr->next_reauth_id_len);
 170                 data->reauth_id_len = attr->next_reauth_id_len;
 171                 wpa_hexdump_ascii(MSG_DEBUG,
 172                                   "EAP-AKA: (encr) AT_NEXT_REAUTH_ID",
 173                                   data->reauth_id,
 174                                   data->reauth_id_len);
 175         }
 176
 177         return 0;
 178 }
 179
 180
 181 static u8 * eap_aka_client_error(struct eap_aka_data *data,
 182                                  const struct eap_hdr *req,
 183                                  size_t *respDataLen, int err)
 184 {
 185         struct eap_sim_msg *msg;
 186
 187         data->state = FAILURE;
 188         data->num_id_req = 0;
 189         data->num_notification = 0;
 190
 191         msg = eap_sim_msg_init(EAP_CODE_RESPONSE, req->identifier,
 192                                EAP_TYPE_AKA, EAP_AKA_SUBTYPE_CLIENT_ERROR);
 193         eap_sim_msg_add(msg, EAP_SIM_AT_CLIENT_ERROR_CODE, err, NULL, 0);
 194         return eap_sim_msg_finish(msg, respDataLen, NULL, NULL, 0);
 195 }
 196
 197
 198 static u8 * eap_aka_authentication_reject(struct eap_aka_data *data,
 199                                           const struct eap_hdr *req,
 200                                           size_t *respDataLen)
 201 {
 202         struct eap_sim_msg *msg;
 203
 204         data->state = FAILURE;
 205         data->num_id_req = 0;
 206         data->num_notification = 0;
 207
 208         wpa_printf(MSG_DEBUG, "Generating EAP-AKA Authentication-Reject "
 209                    "(id=%d)", req->identifier);
 210         msg = eap_sim_msg_init(EAP_CODE_RESPONSE, req->identifier,
 211                                EAP_TYPE_AKA,
 212                                EAP_AKA_SUBTYPE_AUTHENTICATION_REJECT);
 213         return eap_sim_msg_finish(msg, respDataLen, NULL, NULL, 0);
 214 }
 215
 216
 217 static u8 * eap_aka_synchronization_failure(struct eap_aka_data *data,
 218                                             const struct eap_hdr *req,
 219                                             size_t *respDataLen)
 220 {
 221         struct eap_sim_msg *msg;
 222
 223         data->num_id_req = 0;
 224         data->num_notification = 0;
 225
 226         wpa_printf(MSG_DEBUG, "Generating EAP-AKA Synchronization-Failure "
 227                    "(id=%d)", req->identifier);
 228         msg = eap_sim_msg_init(EAP_CODE_RESPONSE, req->identifier,
 229                                EAP_TYPE_AKA,
 230                                EAP_AKA_SUBTYPE_SYNCHRONIZATION_FAILURE);
 231         wpa_printf(MSG_DEBUG, "   AT_AUTS");
 232         eap_sim_msg_add_full(msg, EAP_SIM_AT_AUTS, data->auts,
 233                              EAP_AKA_AUTS_LEN);
 234         return eap_sim_msg_finish(msg, respDataLen, NULL, NULL, 0);
 235 }
 236
 237
 238 static u8 * eap_aka_response_identity(struct eap_sm *sm,
 239                                       struct eap_aka_data *data,
 240                                       const struct eap_hdr *req,
 241                                       size_t *respDataLen,
 242                                       enum eap_sim_id_req id_req)
 243 {
 244         const u8 *identity = NULL;
 245         size_t identity_len = 0;
 246         struct eap_sim_msg *msg;
 247
 248         data->reauth = 0;
 249         if (id_req == ANY_ID && data->reauth_id) {
 250                 identity = data->reauth_id;
 251                 identity_len = data->reauth_id_len;
 252                 data->reauth = 1;
 253         } else if ((id_req == ANY_ID || id_req == FULLAUTH_ID) &&
 254                    data->pseudonym) {
 255                 identity = data->pseudonym;
 256                 identity_len = data->pseudonym_len;
 257                 eap_aka_clear_identities(data, CLEAR_REAUTH_ID);
 258         } else if (id_req != NO_ID_REQ) {
 259                 identity = eap_get_config_identity(sm, &identity_len);
 260                 if (identity) {
 261                         eap_aka_clear_identities(data, CLEAR_PSEUDONYM |
 262                                                  CLEAR_REAUTH_ID);
 263                 }
 264         }
 265         if (id_req != NO_ID_REQ)
 266                 eap_aka_clear_identities(data, CLEAR_EAP_ID);
 267
 268         wpa_printf(MSG_DEBUG, "Generating EAP-AKA Identity (id=%d)",
 269                    req->identifier);
 270         msg = eap_sim_msg_init(EAP_CODE_RESPONSE, req->identifier,
 271                                EAP_TYPE_AKA, EAP_AKA_SUBTYPE_IDENTITY);
 272
 273         if (identity) {
 274                 wpa_hexdump_ascii(MSG_DEBUG, "   AT_IDENTITY",
 275                                   identity, identity_len);
 276                 eap_sim_msg_add(msg, EAP_SIM_AT_IDENTITY, identity_len,
 277                                 identity, identity_len);
 278         }
 279
 280         return eap_sim_msg_finish(msg, respDataLen, NULL, NULL, 0);
 281 }
 282
 283
 284 static u8 * eap_aka_response_challenge(struct eap_aka_data *data,
 285                                        const struct eap_hdr *req,
 286                                        size_t *respDataLen)
 287 {
 288         struct eap_sim_msg *msg;
 289
 290         wpa_printf(MSG_DEBUG, "Generating EAP-AKA Challenge (id=%d)",
 291                    req->identifier);
 292         msg = eap_sim_msg_init(EAP_CODE_RESPONSE, req->identifier,
 293                                EAP_TYPE_AKA, EAP_AKA_SUBTYPE_CHALLENGE);
 294         wpa_printf(MSG_DEBUG, "   AT_RES");
 295         eap_sim_msg_add(msg, EAP_SIM_AT_RES, data->res_len,
 296                         data->res, data->res_len);
 297         wpa_printf(MSG_DEBUG, "   AT_MAC");
 298         eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
 299         return eap_sim_msg_finish(msg, respDataLen, data->k_aut, (u8 *) "", 0);
 300 }
 301
 302
 303 static u8 * eap_aka_response_reauth(struct eap_aka_data *data,
 304                                     const struct eap_hdr *req,
 305                                     size_t *respDataLen, int counter_too_small,
 306                                     const u8 *nonce_s)
 307 {
 308         struct eap_sim_msg *msg;
 309         unsigned int counter;
 310
 311         wpa_printf(MSG_DEBUG, "Generating EAP-AKA Reauthentication (id=%d)",
 312                    req->identifier);
 313         msg = eap_sim_msg_init(EAP_CODE_RESPONSE, req->identifier,
 314                                EAP_TYPE_AKA,
 315                                EAP_AKA_SUBTYPE_REAUTHENTICATION);
 316         wpa_printf(MSG_DEBUG, "   AT_IV");
 317         wpa_printf(MSG_DEBUG, "   AT_ENCR_DATA");
 318         eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV, EAP_SIM_AT_ENCR_DATA);
 319
 320         if (counter_too_small) {
 321                 wpa_printf(MSG_DEBUG, "   *AT_COUNTER_TOO_SMALL");
 322                 eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER_TOO_SMALL, 0, NULL, 0);
 323                 counter = data->counter_too_small;
 324         } else
 325                 counter = data->counter;
 326
 327         wpa_printf(MSG_DEBUG, "   *AT_COUNTER %d", counter);
 328         eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, counter, NULL, 0);
 329
 330         if (eap_sim_msg_add_encr_end(msg, data->k_encr, EAP_SIM_AT_PADDING)) {
 331                 wpa_printf(MSG_WARNING, "EAP-AKA: Failed to encrypt "
 332                            "AT_ENCR_DATA");
 333                 eap_sim_msg_free(msg);
 334                 return NULL;
 335         }
 336         wpa_printf(MSG_DEBUG, "   AT_MAC");
 337         eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
 338         return eap_sim_msg_finish(msg, respDataLen, data->k_aut, nonce_s,
 339                                   EAP_SIM_NONCE_S_LEN);
 340 }
 341
 342
 343 static u8 * eap_aka_response_notification(struct eap_aka_data *data,
 344                                           const struct eap_hdr *req,
 345                                           size_t *respDataLen,
 346                                           u16 notification)
 347 {
 348         struct eap_sim_msg *msg;
 349         u8 *k_aut = (notification & 0x4000) == 0 ? data->k_aut : NULL;
 350
 351         wpa_printf(MSG_DEBUG, "Generating EAP-AKA Notification (id=%d)",
 352                    req->identifier);
 353         msg = eap_sim_msg_init(EAP_CODE_RESPONSE, req->identifier,
 354                                EAP_TYPE_AKA, EAP_AKA_SUBTYPE_NOTIFICATION);
 355         if (k_aut && data->reauth) {
 356                 wpa_printf(MSG_DEBUG, "   AT_IV");
 357                 wpa_printf(MSG_DEBUG, "   AT_ENCR_DATA");
 358                 eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV,
 359                                            EAP_SIM_AT_ENCR_DATA);
 360                 wpa_printf(MSG_DEBUG, "   *AT_COUNTER %d", data->counter);
 361                 eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, data->counter,
 362                                 NULL, 0);
 363                 if (eap_sim_msg_add_encr_end(msg, data->k_encr,
 364                                              EAP_SIM_AT_PADDING)) {
 365                         wpa_printf(MSG_WARNING, "EAP-AKA: Failed to encrypt "
 366                                    "AT_ENCR_DATA");
 367                         eap_sim_msg_free(msg);
 368                         return NULL;
 369                 }
 370         }
 371         if (k_aut) {
 372                 wpa_printf(MSG_DEBUG, "   AT_MAC");
 373                 eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
 374         }
 375         return eap_sim_msg_finish(msg, respDataLen, k_aut, (u8 *) "", 0);
 376 }
 377
 378
 379 static u8 * eap_aka_process_identity(struct eap_sm *sm,
 380                                      struct eap_aka_data *data,
 381                                      const struct eap_hdr *req,
 382                                      size_t *respDataLen,
 383                                      struct eap_sim_attrs *attr)
 384 {
 385         int id_error;
 386
 387         wpa_printf(MSG_DEBUG, "EAP-AKA: subtype Identity");
 388
 389         id_error = 0;
 390         switch (attr->id_req) {
 391         case NO_ID_REQ:
 392                 break;
 393         case ANY_ID:
 394                 if (data->num_id_req > 0)
 395                         id_error++;
 396                 data->num_id_req++;
 397                 break;
 398         case FULLAUTH_ID:
 399                 if (data->num_id_req > 1)
 400                         id_error++;
 401                 data->num_id_req++;
 402                 break;
 403         case PERMANENT_ID:
 404                 if (data->num_id_req > 2)
 405                         id_error++;
 406                 data->num_id_req++;
 407                 break;
 408         }
 409         if (id_error) {
 410                 wpa_printf(MSG_INFO, "EAP-AKA: Too many ID requests "
 411                            "used within one authentication");
 412                 return eap_aka_client_error(data, req, respDataLen,
 413                                             EAP_AKA_UNABLE_TO_PROCESS_PACKET);
 414         }
 415
 416         return eap_aka_response_identity(sm, data, req, respDataLen,
 417                                          attr->id_req);
 418 }
 419
 420
 421 static u8 * eap_aka_process_challenge(struct eap_sm *sm,
 422                                       struct eap_aka_data *data,
 423                                       const struct eap_hdr *req,
 424                                       size_t reqDataLen,
 425                                       size_t *respDataLen,
 426                                       struct eap_sim_attrs *attr)
 427 {
 428         const u8 *identity;
 429         size_t identity_len;
 430         int res;
 431         struct eap_sim_attrs eattr;
 432
 433         wpa_printf(MSG_DEBUG, "EAP-AKA: subtype Challenge");
 434         data->reauth = 0;
 435         if (!attr->mac || !attr->rand || !attr->autn) {
 436                 wpa_printf(MSG_WARNING, "EAP-AKA: Challenge message "
 437                            "did not include%s%s%s",
 438                            !attr->mac ? " AT_MAC" : "",
 439                            !attr->rand ? " AT_RAND" : "",
 440                            !attr->autn ? " AT_AUTN" : "");
 441                 return eap_aka_client_error(data, req, respDataLen,
 442                                             EAP_AKA_UNABLE_TO_PROCESS_PACKET);
 443         }
 444         os_memcpy(data->rand, attr->rand, EAP_AKA_RAND_LEN);
 445         os_memcpy(data->autn, attr->autn, EAP_AKA_AUTN_LEN);
 446
 447         res = eap_aka_umts_auth(sm, data);
 448         if (res == -1) {
 449                 wpa_printf(MSG_WARNING, "EAP-AKA: UMTS authentication "
 450                            "failed (AUTN)");
 451                 return eap_aka_authentication_reject(data, req, respDataLen);
 452         } else if (res == -2) {
 453                 wpa_printf(MSG_WARNING, "EAP-AKA: UMTS authentication "
 454                            "failed (AUTN seq# -> AUTS)");
 455                 return eap_aka_synchronization_failure(data, req, respDataLen);
 456         } else if (res) {
 457                 wpa_printf(MSG_WARNING, "EAP-AKA: UMTS authentication failed");
 458                 return eap_aka_client_error(data, req, respDataLen,
 459                                             EAP_AKA_UNABLE_TO_PROCESS_PACKET);
 460         }
 461         if (data->last_eap_identity) {
 462                 identity = data->last_eap_identity;
 463                 identity_len = data->last_eap_identity_len;
 464         } else if (data->pseudonym) {
 465                 identity = data->pseudonym;
 466                 identity_len = data->pseudonym_len;
 467         } else
 468                 identity = eap_get_config_identity(sm, &identity_len);
 469         wpa_hexdump_ascii(MSG_DEBUG, "EAP-AKA: Selected identity for MK "
 470                           "derivation", identity, identity_len);
 471         eap_aka_derive_mk(identity, identity_len, data->ik, data->ck,
 472                           data->mk);
 473         eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut, data->msk,
 474                             data->emsk);
 475         if (eap_sim_verify_mac(data->k_aut, (const u8 *) req, reqDataLen,
 476                                attr->mac, (u8 *) "", 0)) {
 477                 wpa_printf(MSG_WARNING, "EAP-AKA: Challenge message "
 478                            "used invalid AT_MAC");
 479                 return eap_aka_client_error(data, req, respDataLen,
 480                                             EAP_AKA_UNABLE_TO_PROCESS_PACKET);
 481         }
 482
 483         /* Old reauthentication and pseudonym identities must not be used
 484          * anymore. In other words, if no new identities are received, full
 485          * authentication will be used on next reauthentication. */
 486         eap_aka_clear_identities(data, CLEAR_PSEUDONYM | CLEAR_REAUTH_ID |
 487                                  CLEAR_EAP_ID);
 488
 489         if (attr->encr_data) {
 490                 u8 *decrypted;
 491                 decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
 492                                                attr->encr_data_len, attr->iv,
 493                                                &eattr, 0);
 494                 if (decrypted == NULL) {
 495                         return eap_aka_client_error(
 496                                 data, req, respDataLen,
 497                                 EAP_AKA_UNABLE_TO_PROCESS_PACKET);
 498                 }
 499                 eap_aka_learn_ids(data, &eattr);
 500                 os_free(decrypted);
 501         }
 502
 503         if (data->state != FAILURE)
 504                 data->state = SUCCESS;
 505
 506         data->num_id_req = 0;
 507         data->num_notification = 0;
 508         /* RFC 4187 specifies that counter is initialized to one after
 509          * fullauth, but initializing it to zero makes it easier to implement
 510          * reauth verification. */
 511         data->counter = 0;
 512         return eap_aka_response_challenge(data, req, respDataLen);
 513 }
 514
 515
 516 static int eap_aka_process_notification_reauth(struct eap_aka_data *data,
 517                                                struct eap_sim_attrs *attr)
 518 {
 519         struct eap_sim_attrs eattr;
 520         u8 *decrypted;
 521
 522         if (attr->encr_data == NULL || attr->iv == NULL) {
 523                 wpa_printf(MSG_WARNING, "EAP-AKA: Notification message after "
 524                            "reauth did not include encrypted data");
 525                 return -1;
 526         }
 527
 528         decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
 529                                        attr->encr_data_len, attr->iv, &eattr,
 530                                        0);
 531         if (decrypted == NULL) {
 532                 wpa_printf(MSG_WARNING, "EAP-AKA: Failed to parse encrypted "
 533                            "data from notification message");
 534                 return -1;
 535         }
 536
 537         if (eattr.counter < 0 || (size_t) eattr.counter != data->counter) {
 538                 wpa_printf(MSG_WARNING, "EAP-AKA: Counter in notification "
 539                            "message does not match with counter in reauth "
 540                            "message");
 541                 os_free(decrypted);
 542                 return -1;
 543         }
 544
 545         os_free(decrypted);
 546         return 0;
 547 }
 548
 549
 550 static int eap_aka_process_notification_auth(struct eap_aka_data *data,
 551                                              const struct eap_hdr *req,
 552                                              size_t reqDataLen,
 553                                              struct eap_sim_attrs *attr)
 554 {
 555         if (attr->mac == NULL) {
 556                 wpa_printf(MSG_INFO, "EAP-AKA: no AT_MAC in after_auth "
 557                            "Notification message");
 558                 return -1;
 559         }
 560
 561         if (eap_sim_verify_mac(data->k_aut, (const u8 *) req, reqDataLen,
 562                                attr->mac, (u8 *) "", 0)) {
 563                 wpa_printf(MSG_WARNING, "EAP-AKA: Notification message "
 564                            "used invalid AT_MAC");
 565                 return -1;
 566         }
 567
 568         if (data->reauth &&
 569             eap_aka_process_notification_reauth(data, attr)) {
 570                 wpa_printf(MSG_WARNING, "EAP-AKA: Invalid notification "
 571                            "message after reauth");
 572                 return -1;
 573         }
 574
 575         return 0;
 576 }
 577
 578
 579 static u8 * eap_aka_process_notification(struct eap_sm *sm,
 580                                          struct eap_aka_data *data,
 581                                          const struct eap_hdr *req,
 582                                          size_t reqDataLen,
 583                                          size_t *respDataLen,
 584                                          struct eap_sim_attrs *attr)
 585 {
 586         wpa_printf(MSG_DEBUG, "EAP-AKA: subtype Notification");
 587         if (data->num_notification > 0) {
 588                 wpa_printf(MSG_INFO, "EAP-AKA: too many notification "
 589                            "rounds (only one allowed)");
 590                 return eap_aka_client_error(data, req, respDataLen,
 591                                             EAP_AKA_UNABLE_TO_PROCESS_PACKET);
 592         }
 593         data->num_notification++;
 594         if (attr->notification == -1) {
 595                 wpa_printf(MSG_INFO, "EAP-AKA: no AT_NOTIFICATION in "
 596                            "Notification message");
 597                 return eap_aka_client_error(data, req, respDataLen,
 598                                             EAP_AKA_UNABLE_TO_PROCESS_PACKET);
 599         }
 600
 601         if ((attr->notification & 0x4000) == 0 &&
 602             eap_aka_process_notification_auth(data, req, reqDataLen, attr)) {
 603                 return eap_aka_client_error(data, req, respDataLen,
 604                                             EAP_AKA_UNABLE_TO_PROCESS_PACKET);
 605         }
 606
 607         eap_sim_report_notification(sm->msg_ctx, attr->notification, 1);
 608         if (attr->notification >= 0 && attr->notification < 32768) {
 609                 data->state = FAILURE;
 610         }
 611         return eap_aka_response_notification(data, req, respDataLen,
 612                                              attr->notification);
 613 }
 614
 615
 616 static u8 * eap_aka_process_reauthentication(struct eap_sm *sm,
 617                                              struct eap_aka_data *data,
 618                                              const struct eap_hdr *req,
 619                                              size_t reqDataLen,
 620                                              size_t *respDataLen,
 621                                              struct eap_sim_attrs *attr)
 622 {
 623         struct eap_sim_attrs eattr;
 624         u8 *decrypted;
 625
 626         wpa_printf(MSG_DEBUG, "EAP-AKA: subtype Reauthentication");
 627
 628         if (data->reauth_id == NULL) {
 629                 wpa_printf(MSG_WARNING, "EAP-AKA: Server is trying "
 630                            "reauthentication, but no reauth_id available");
 631                 return eap_aka_client_error(data, req, respDataLen,
 632                                             EAP_AKA_UNABLE_TO_PROCESS_PACKET);
 633         }
 634
 635         data->reauth = 1;
 636         if (eap_sim_verify_mac(data->k_aut, (const u8 *) req, reqDataLen,
 637                                attr->mac, (u8 *) "", 0)) {
 638                 wpa_printf(MSG_WARNING, "EAP-AKA: Reauthentication "
 639                            "did not have valid AT_MAC");
 640                 return eap_aka_client_error(data, req, respDataLen,
 641                                             EAP_AKA_UNABLE_TO_PROCESS_PACKET);
 642         }
 643
 644         if (attr->encr_data == NULL || attr->iv == NULL) {
 645                 wpa_printf(MSG_WARNING, "EAP-AKA: Reauthentication "
 646                            "message did not include encrypted data");
 647                 return eap_aka_client_error(data, req, respDataLen,
 648                                             EAP_AKA_UNABLE_TO_PROCESS_PACKET);
 649         }
 650
 651         decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
 652                                        attr->encr_data_len, attr->iv, &eattr,
 653                                        0);
 654         if (decrypted == NULL) {
 655                 wpa_printf(MSG_WARNING, "EAP-AKA: Failed to parse encrypted "
 656                            "data from reauthentication message");
 657                 return eap_aka_client_error(data, req, respDataLen,
 658                                             EAP_AKA_UNABLE_TO_PROCESS_PACKET);
 659         }
 660
 661         if (eattr.nonce_s == NULL || eattr.counter < 0) {
 662                 wpa_printf(MSG_INFO, "EAP-AKA: (encr) No%s%s in reauth packet",
 663                            !eattr.nonce_s ? " AT_NONCE_S" : "",
 664                            eattr.counter < 0 ? " AT_COUNTER" : "");
 665                 os_free(decrypted);
 666                 return eap_aka_client_error(data, req, respDataLen,
 667                                             EAP_AKA_UNABLE_TO_PROCESS_PACKET);
 668         }
 669
 670         if (eattr.counter < 0 || (size_t) eattr.counter <= data->counter) {
 671                 u8 *res;
 672                 wpa_printf(MSG_INFO, "EAP-AKA: (encr) Invalid counter "
 673                            "(%d <= %d)", eattr.counter, data->counter);
 674                 data->counter_too_small = eattr.counter;
 675
 676                 eap_sim_derive_keys_reauth(eattr.counter, data->reauth_id,
 677                                            data->reauth_id_len, eattr.nonce_s,
 678                                            data->mk, NULL, NULL);
 679
 680                 /* Reply using Re-auth w/ AT_COUNTER_TOO_SMALL. The current
 681                  * reauth_id must not be used to start a new reauthentication.
 682                  * However, since it was used in the last EAP-Response-Identity
 683                  * packet, it has to saved for the following fullauth to be
 684                  * used in MK derivation. */
 685                 os_free(data->last_eap_identity);
 686                 data->last_eap_identity = data->reauth_id;
 687                 data->last_eap_identity_len = data->reauth_id_len;
 688                 data->reauth_id = NULL;
 689                 data->reauth_id_len = 0;
 690
 691                 res = eap_aka_response_reauth(data, req, respDataLen, 1,
 692                                               eattr.nonce_s);
 693                 os_free(decrypted);
 694
 695                 return res;
 696         }
 697         data->counter = eattr.counter;
 698
 699         os_memcpy(data->nonce_s, eattr.nonce_s, EAP_SIM_NONCE_S_LEN);
 700         wpa_hexdump(MSG_DEBUG, "EAP-AKA: (encr) AT_NONCE_S",
 701                     data->nonce_s, EAP_SIM_NONCE_S_LEN);
 702
 703         eap_sim_derive_keys_reauth(data->counter,
 704                                    data->reauth_id, data->reauth_id_len,
 705                                    data->nonce_s, data->mk, data->msk,
 706                                    data->emsk);
 707         eap_aka_clear_identities(data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
 708         eap_aka_learn_ids(data, &eattr);
 709
 710         if (data->state != FAILURE)
 711                 data->state = SUCCESS;
 712
 713         data->num_id_req = 0;
 714         data->num_notification = 0;
 715         if (data->counter > EAP_AKA_MAX_FAST_REAUTHS) {
 716                 wpa_printf(MSG_DEBUG, "EAP-AKA: Maximum number of "
 717                            "fast reauths performed - force fullauth");
 718                 eap_aka_clear_identities(data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
 719         }
 720         os_free(decrypted);
 721         return eap_aka_response_reauth(data, req, respDataLen, 0,
 722                                        data->nonce_s);
 723 }
 724
 725
 726 static u8 * eap_aka_process(struct eap_sm *sm, void *priv,
 727                             struct eap_method_ret *ret,
 728                             const u8 *reqData, size_t reqDataLen,
 729                             size_t *respDataLen)
 730 {
 731         struct eap_aka_data *data = priv;
 732         const struct eap_hdr *req;
 733         u8 subtype, *res;
 734         const u8 *pos;
 735         struct eap_sim_attrs attr;
 736         size_t len;
 737
 738         wpa_hexdump(MSG_DEBUG, "EAP-AKA: EAP data", reqData, reqDataLen);
 739         if (eap_get_config_identity(sm, &len) == NULL) {
 740                 wpa_printf(MSG_INFO, "EAP-AKA: Identity not configured");
 741                 eap_sm_request_identity(sm);
 742                 ret->ignore = TRUE;
 743                 return NULL;
 744         }
 745
 746         pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_AKA,
 747                                reqData, reqDataLen, &len);
 748         if (pos == NULL || len < 1) {
 749                 ret->ignore = TRUE;
 750                 return NULL;
 751         }
 752         req = (const struct eap_hdr *) reqData;
 753         len = be_to_host16(req->length);
 754
 755         ret->ignore = FALSE;
 756         ret->methodState = METHOD_MAY_CONT;
 757         ret->decision = DECISION_FAIL;
 758         ret->allowNotifications = TRUE;
 759
 760         subtype = *pos++;
 761         wpa_printf(MSG_DEBUG, "EAP-AKA: Subtype=%d", subtype);
 762         pos += 2; /* Reserved */
 763
 764         if (eap_sim_parse_attr(pos, reqData + len, &attr, 1, 0)) {
 765                 res = eap_aka_client_error(data, req, respDataLen,
 766                                            EAP_AKA_UNABLE_TO_PROCESS_PACKET);
 767                 goto done;
 768         }
 769
 770         switch (subtype) {
 771         case EAP_AKA_SUBTYPE_IDENTITY:
 772                 res = eap_aka_process_identity(sm, data, req,
 773                                                respDataLen, &attr);
 774                 break;
 775         case EAP_AKA_SUBTYPE_CHALLENGE:
 776                 res = eap_aka_process_challenge(sm, data, req, len,
 777                                                 respDataLen, &attr);
 778                 break;
 779         case EAP_AKA_SUBTYPE_NOTIFICATION:
 780                 res = eap_aka_process_notification(sm, data, req, len,
 781                                                    respDataLen, &attr);
 782                 break;
 783         case EAP_AKA_SUBTYPE_REAUTHENTICATION:
 784                 res = eap_aka_process_reauthentication(sm, data, req, len,
 785                                                        respDataLen, &attr);
 786                 break;
 787         case EAP_AKA_SUBTYPE_CLIENT_ERROR:
 788                 wpa_printf(MSG_DEBUG, "EAP-AKA: subtype Client-Error");
 789                 res = eap_aka_client_error(data, req, respDataLen,
 790                                            EAP_AKA_UNABLE_TO_PROCESS_PACKET);
 791                 break;
 792         default:
 793                 wpa_printf(MSG_DEBUG, "EAP-AKA: Unknown subtype=%d", subtype);
 794                 res = eap_aka_client_error(data, req, respDataLen,
 795                                            EAP_AKA_UNABLE_TO_PROCESS_PACKET);
 796                 break;
 797         }
 798
 799 done:
 800         if (data->state == FAILURE) {
 801                 ret->decision = DECISION_FAIL;
 802                 ret->methodState = METHOD_DONE;
 803         } else if (data->state == SUCCESS) {
 804                 ret->decision = DECISION_COND_SUCC;
 805                 /*
 806                  * It is possible for the server to reply with AKA
 807                  * Notification, so we must allow the method to continue and
 808                  * not only accept EAP-Success at this point.
 809                  */
 810                 ret->methodState = METHOD_MAY_CONT;
 811         }
 812
 813         if (ret->methodState == METHOD_DONE) {
 814                 ret->allowNotifications = FALSE;
 815         }
 816
 817         return res;
 818 }
 819
 820
 821 static Boolean eap_aka_has_reauth_data(struct eap_sm *sm, void *priv)
 822 {
 823         struct eap_aka_data *data = priv;
 824         return data->pseudonym || data->reauth_id;
 825 }
 826
 827
 828 static void eap_aka_deinit_for_reauth(struct eap_sm *sm, void *priv)
 829 {
 830         struct eap_aka_data *data = priv;
 831         eap_aka_clear_identities(data, CLEAR_EAP_ID);
 832 }
 833
 834
 835 static void * eap_aka_init_for_reauth(struct eap_sm *sm, void *priv)
 836 {
 837         struct eap_aka_data *data = priv;
 838         data->num_id_req = 0;
 839         data->num_notification = 0;
 840         data->state = CONTINUE;
 841         return priv;
 842 }
 843
 844
 845 static const u8 * eap_aka_get_identity(struct eap_sm *sm, void *priv,
 846                                        size_t *len)
 847 {
 848         struct eap_aka_data *data = priv;
 849
 850         if (data->reauth_id) {
 851                 *len = data->reauth_id_len;
 852                 return data->reauth_id;
 853         }
 854
 855         if (data->pseudonym) {
 856                 *len = data->pseudonym_len;
 857                 return data->pseudonym;
 858         }
 859
 860         return NULL;
 861 }
 862
 863
 864 static Boolean eap_aka_isKeyAvailable(struct eap_sm *sm, void *priv)
 865 {
 866         struct eap_aka_data *data = priv;
 867         return data->state == SUCCESS;
 868 }
 869
 870
 871 static u8 * eap_aka_getKey(struct eap_sm *sm, void *priv, size_t *len)
 872 {
 873         struct eap_aka_data *data = priv;
 874         u8 *key;
 875
 876         if (data->state != SUCCESS)
 877                 return NULL;
 878
 879         key = os_malloc(EAP_SIM_KEYING_DATA_LEN);
 880         if (key == NULL)
 881                 return NULL;
 882
 883         *len = EAP_SIM_KEYING_DATA_LEN;
 884         os_memcpy(key, data->msk, EAP_SIM_KEYING_DATA_LEN);
 885
 886         return key;
 887 }
 888
 889
 890 static u8 * eap_aka_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
 891 {
 892         struct eap_aka_data *data = priv;
 893         u8 *key;
 894
 895         if (data->state != SUCCESS)
 896                 return NULL;
 897
 898         key = os_malloc(EAP_EMSK_LEN);
 899         if (key == NULL)
 900                 return NULL;
 901
 902         *len = EAP_EMSK_LEN;
 903         os_memcpy(key, data->emsk, EAP_EMSK_LEN);
 904
 905         return key;
 906 }
 907
 908
 909 int eap_peer_aka_register(void)
 910 {
 911         struct eap_method *eap;
 912         int ret;
 913
 914         eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
 915                                     EAP_VENDOR_IETF, EAP_TYPE_AKA, "AKA");
 916         if (eap == NULL)
 917                 return -1;
 918
 919         eap->init = eap_aka_init;
 920         eap->deinit = eap_aka_deinit;
 921         eap->process = eap_aka_process;
 922         eap->isKeyAvailable = eap_aka_isKeyAvailable;
 923         eap->getKey = eap_aka_getKey;
 924         eap->has_reauth_data = eap_aka_has_reauth_data;
 925         eap->deinit_for_reauth = eap_aka_deinit_for_reauth;
 926         eap->init_for_reauth = eap_aka_init_for_reauth;
 927         eap->get_identity = eap_aka_get_identity;
 928         eap->get_emsk = eap_aka_get_emsk;
 929
 930         ret = eap_peer_method_register(eap);
 931         if (ret)
 932                 eap_peer_method_free(eap);
 933         return ret;
 934 }