src/eap_peer/eap_eke.c

   1 /*
   2  * EAP peer method: EAP-EKE (RFC 6124)
   3  * Copyright (c) 2013, Jouni Malinen <j@w1.fi>
   4  *
   5  * This software may be distributed under the terms of the BSD license.
   6  * See README for more details.
   7  */
   8
   9 #include "includes.h"
  10
  11 #include "common.h"
  12 #include "crypto/random.h"
  13 #include "eap_peer/eap_i.h"
  14 #include "eap_common/eap_eke_common.h"
  15
  16 struct eap_eke_data {
  17         enum {
  18                 IDENTITY, COMMIT, CONFIRM, SUCCESS, FAILURE
  19         } state;
  20         u8 msk[EAP_MSK_LEN];
  21         u8 emsk[EAP_EMSK_LEN];
  22         u8 *peerid;
  23         size_t peerid_len;
  24         u8 *serverid;
  25         size_t serverid_len;
  26         u8 dh_priv[EAP_EKE_MAX_DH_LEN];
  27         struct eap_eke_session sess;
  28         u8 nonce_p[EAP_EKE_MAX_NONCE_LEN];
  29         u8 nonce_s[EAP_EKE_MAX_NONCE_LEN];
  30         struct wpabuf *msgs;
  31         u8 dhgroup; /* forced DH group or 0 to allow all supported */
  32         u8 encr; /* forced encryption algorithm or 0 to allow all supported */
  33         u8 prf; /* forced PRF or 0 to allow all supported */
  34         u8 mac; /* forced MAC or 0 to allow all supported */
  35 };
  36
  37
  38 static const char * eap_eke_state_txt(int state)
  39 {
  40         switch (state) {
  41         case IDENTITY:
  42                 return "IDENTITY";
  43         case COMMIT:
  44                 return "COMMIT";
  45         case CONFIRM:
  46                 return "CONFIRM";
  47         case SUCCESS:
  48                 return "SUCCESS";
  49         case FAILURE:
  50                 return "FAILURE";
  51         default:
  52                 return "?";
  53         }
  54 }
  55
  56
  57 static void eap_eke_state(struct eap_eke_data *data, int state)
  58 {
  59         wpa_printf(MSG_DEBUG, "EAP-EKE: %s -> %s",
  60                    eap_eke_state_txt(data->state), eap_eke_state_txt(state));
  61         data->state = state;
  62 }
  63
  64
  65 static void eap_eke_deinit(struct eap_sm *sm, void *priv);
  66
  67
  68 static void * eap_eke_init(struct eap_sm *sm)
  69 {
  70         struct eap_eke_data *data;
  71         const u8 *identity, *password;
  72         size_t identity_len, password_len;
  73         const char *phase1;
  74
  75         password = eap_get_config_password(sm, &password_len);
  76         if (!password) {
  77                 wpa_printf(MSG_INFO, "EAP-EKE: No password configured");
  78                 return NULL;
  79         }
  80
  81         data = os_zalloc(sizeof(*data));
  82         if (data == NULL)
  83                 return NULL;
  84         eap_eke_state(data, IDENTITY);
  85
  86         identity = eap_get_config_identity(sm, &identity_len);
  87         if (identity) {
  88                 data->peerid = os_memdup(identity, identity_len);
  89                 if (data->peerid == NULL) {
  90                         eap_eke_deinit(sm, data);
  91                         return NULL;
  92                 }
  93                 data->peerid_len = identity_len;
  94         }
  95
  96         phase1 = eap_get_config_phase1(sm);
  97         if (phase1) {
  98                 const char *pos;
  99
 100                 pos = os_strstr(phase1, "dhgroup=");
 101                 if (pos) {
 102                         data->dhgroup = atoi(pos + 8);
 103                         wpa_printf(MSG_DEBUG, "EAP-EKE: Forced dhgroup %u",
 104                                    data->dhgroup);
 105                 }
 106
 107                 pos = os_strstr(phase1, "encr=");
 108                 if (pos) {
 109                         data->encr = atoi(pos + 5);
 110                         wpa_printf(MSG_DEBUG, "EAP-EKE: Forced encr %u",
 111                                    data->encr);
 112                 }
 113
 114                 pos = os_strstr(phase1, "prf=");
 115                 if (pos) {
 116                         data->prf = atoi(pos + 4);
 117                         wpa_printf(MSG_DEBUG, "EAP-EKE: Forced prf %u",
 118                                    data->prf);
 119                 }
 120
 121                 pos = os_strstr(phase1, "mac=");
 122                 if (pos) {
 123                         data->mac = atoi(pos + 4);
 124                         wpa_printf(MSG_DEBUG, "EAP-EKE: Forced mac %u",
 125                                    data->mac);
 126                 }
 127         }
 128
 129         return data;
 130 }
 131
 132
 133 static void eap_eke_deinit(struct eap_sm *sm, void *priv)
 134 {
 135         struct eap_eke_data *data = priv;
 136         eap_eke_session_clean(&data->sess);
 137         os_free(data->serverid);
 138         os_free(data->peerid);
 139         wpabuf_free(data->msgs);
 140         bin_clear_free(data, sizeof(*data));
 141 }
 142
 143
 144 static struct wpabuf * eap_eke_build_msg(struct eap_eke_data *data, int id,
 145                                          size_t length, u8 eke_exch)
 146 {
 147         struct wpabuf *msg;
 148         size_t plen;
 149
 150         plen = 1 + length;
 151
 152         msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_EKE, plen,
 153                             EAP_CODE_RESPONSE, id);
 154         if (msg == NULL) {
 155                 wpa_printf(MSG_ERROR, "EAP-EKE: Failed to allocate memory");
 156                 return NULL;
 157         }
 158
 159         wpabuf_put_u8(msg, eke_exch);
 160
 161         return msg;
 162 }
 163
 164
 165 static int eap_eke_supp_dhgroup(u8 dhgroup)
 166 {
 167         return dhgroup == EAP_EKE_DHGROUP_EKE_2 ||
 168                 dhgroup == EAP_EKE_DHGROUP_EKE_5 ||
 169                 dhgroup == EAP_EKE_DHGROUP_EKE_14 ||
 170                 dhgroup == EAP_EKE_DHGROUP_EKE_15 ||
 171                 dhgroup == EAP_EKE_DHGROUP_EKE_16;
 172 }
 173
 174
 175 static int eap_eke_supp_encr(u8 encr)
 176 {
 177         return encr == EAP_EKE_ENCR_AES128_CBC;
 178 }
 179
 180
 181 static int eap_eke_supp_prf(u8 prf)
 182 {
 183         return prf == EAP_EKE_PRF_HMAC_SHA1 ||
 184                 prf == EAP_EKE_PRF_HMAC_SHA2_256;
 185 }
 186
 187
 188 static int eap_eke_supp_mac(u8 mac)
 189 {
 190         return mac == EAP_EKE_MAC_HMAC_SHA1 ||
 191                 mac == EAP_EKE_MAC_HMAC_SHA2_256;
 192 }
 193
 194
 195 static struct wpabuf * eap_eke_build_fail(struct eap_eke_data *data,
 196                                           struct eap_method_ret *ret,
 197                                           u8 id, u32 failure_code)
 198 {
 199         struct wpabuf *resp;
 200
 201         wpa_printf(MSG_DEBUG, "EAP-EKE: Sending EAP-EKE-Failure/Response - code=0x%x",
 202                    failure_code);
 203
 204         resp = eap_eke_build_msg(data, id, 4, EAP_EKE_FAILURE);
 205         if (resp)
 206                 wpabuf_put_be32(resp, failure_code);
 207
 208         os_memset(data->dh_priv, 0, sizeof(data->dh_priv));
 209         eap_eke_session_clean(&data->sess);
 210
 211         eap_eke_state(data, FAILURE);
 212         ret->methodState = METHOD_DONE;
 213         ret->decision = DECISION_FAIL;
 214         ret->allowNotifications = FALSE;
 215
 216         return resp;
 217 }
 218
 219
 220 static struct wpabuf * eap_eke_process_id(struct eap_eke_data *data,
 221                                           struct eap_method_ret *ret,
 222                                           const struct wpabuf *reqData,
 223                                           const u8 *payload,
 224                                           size_t payload_len)
 225 {
 226         struct wpabuf *resp;
 227         unsigned num_prop, i;
 228         const u8 *pos, *end;
 229         const u8 *prop = NULL;
 230         u8 idtype;
 231         u8 id = eap_get_id(reqData);
 232
 233         if (data->state != IDENTITY) {
 234                 return eap_eke_build_fail(data, ret, id,
 235                                           EAP_EKE_FAIL_PROTO_ERROR);
 236         }
 237
 238         wpa_printf(MSG_DEBUG, "EAP-EKE: Received EAP-EKE-ID/Request");
 239
 240         if (payload_len < 2 + 4) {
 241                 wpa_printf(MSG_DEBUG, "EAP-EKE: Too short ID/Request Data");
 242                 return eap_eke_build_fail(data, ret, id,
 243                                           EAP_EKE_FAIL_PROTO_ERROR);
 244         }
 245
 246         pos = payload;
 247         end = payload + payload_len;
 248
 249         num_prop = *pos++;
 250         pos++; /* Ignore Reserved field */
 251
 252         if (pos + num_prop * 4 > end) {
 253                 wpa_printf(MSG_DEBUG, "EAP-EKE: Too short ID/Request Data (num_prop=%u)",
 254                            num_prop);
 255                 return eap_eke_build_fail(data, ret, id,
 256                                           EAP_EKE_FAIL_PROTO_ERROR);
 257         }
 258
 259         for (i = 0; i < num_prop; i++) {
 260                 const u8 *tmp = pos;
 261
 262                 wpa_printf(MSG_DEBUG, "EAP-EKE: Proposal #%u: dh=%u encr=%u prf=%u mac=%u",
 263                            i, pos[0], pos[1], pos[2], pos[3]);
 264                 pos += 4;
 265
 266                 if ((data->dhgroup && data->dhgroup != *tmp) ||
 267                     !eap_eke_supp_dhgroup(*tmp))
 268                         continue;
 269                 tmp++;
 270                 if ((data->encr && data->encr != *tmp) ||
 271                     !eap_eke_supp_encr(*tmp))
 272                         continue;
 273                 tmp++;
 274                 if ((data->prf && data->prf != *tmp) ||
 275                     !eap_eke_supp_prf(*tmp))
 276                         continue;
 277                 tmp++;
 278                 if ((data->mac && data->mac != *tmp) ||
 279                     !eap_eke_supp_mac(*tmp))
 280                         continue;
 281
 282                 prop = tmp - 3;
 283                 if (eap_eke_session_init(&data->sess, prop[0], prop[1], prop[2],
 284                                          prop[3]) < 0) {
 285                         prop = NULL;
 286                         continue;
 287                 }
 288
 289                 wpa_printf(MSG_DEBUG, "EAP-EKE: Selected proposal");
 290                 break;
 291         }
 292
 293         if (prop == NULL) {
 294                 wpa_printf(MSG_DEBUG, "EAP-EKE: No acceptable proposal found");
 295                 return eap_eke_build_fail(data, ret, id,
 296                                           EAP_EKE_FAIL_NO_PROPOSAL_CHOSEN);
 297         }
 298
 299         pos += (num_prop - i - 1) * 4;
 300
 301         if (pos == end) {
 302                 wpa_printf(MSG_DEBUG, "EAP-EKE: Too short ID/Request Data to include IDType/Identity");
 303                 return eap_eke_build_fail(data, ret, id,
 304                                           EAP_EKE_FAIL_PROTO_ERROR);
 305         }
 306
 307         idtype = *pos++;
 308         wpa_printf(MSG_DEBUG, "EAP-EKE: Server IDType %u", idtype);
 309         wpa_hexdump_ascii(MSG_DEBUG, "EAP-EKE: Server Identity",
 310                           pos, end - pos);
 311         os_free(data->serverid);
 312         data->serverid = os_memdup(pos, end - pos);
 313         if (data->serverid == NULL) {
 314                 return eap_eke_build_fail(data, ret, id,
 315                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 316         }
 317         data->serverid_len = end - pos;
 318
 319         wpa_printf(MSG_DEBUG, "EAP-EKE: Sending EAP-EKE-ID/Response");
 320
 321         resp = eap_eke_build_msg(data, id,
 322                                  2 + 4 + 1 + data->peerid_len,
 323                                  EAP_EKE_ID);
 324         if (resp == NULL) {
 325                 return eap_eke_build_fail(data, ret, id,
 326                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 327         }
 328
 329         wpabuf_put_u8(resp, 1); /* NumProposals */
 330         wpabuf_put_u8(resp, 0); /* Reserved */
 331         wpabuf_put_data(resp, prop, 4); /* Selected Proposal */
 332         wpabuf_put_u8(resp, EAP_EKE_ID_NAI);
 333         if (data->peerid)
 334                 wpabuf_put_data(resp, data->peerid, data->peerid_len);
 335
 336         wpabuf_free(data->msgs);
 337         data->msgs = wpabuf_alloc(wpabuf_len(reqData) + wpabuf_len(resp));
 338         if (data->msgs == NULL) {
 339                 wpabuf_free(resp);
 340                 return eap_eke_build_fail(data, ret, id,
 341                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 342         }
 343         wpabuf_put_buf(data->msgs, reqData);
 344         wpabuf_put_buf(data->msgs, resp);
 345
 346         eap_eke_state(data, COMMIT);
 347
 348         return resp;
 349 }
 350
 351
 352 static struct wpabuf * eap_eke_process_commit(struct eap_sm *sm,
 353                                               struct eap_eke_data *data,
 354                                               struct eap_method_ret *ret,
 355                                               const struct wpabuf *reqData,
 356                                               const u8 *payload,
 357                                               size_t payload_len)
 358 {
 359         struct wpabuf *resp;
 360         const u8 *pos, *end, *dhcomp;
 361         size_t prot_len;
 362         u8 *rpos;
 363         u8 key[EAP_EKE_MAX_KEY_LEN];
 364         u8 pub[EAP_EKE_MAX_DH_LEN];
 365         const u8 *password;
 366         size_t password_len;
 367         u8 id = eap_get_id(reqData);
 368
 369         if (data->state != COMMIT) {
 370                 wpa_printf(MSG_DEBUG, "EAP-EKE: EAP-EKE-Commit/Request received in unexpected state (%d)", data->state);
 371                 return eap_eke_build_fail(data, ret, id,
 372                                           EAP_EKE_FAIL_PROTO_ERROR);
 373         }
 374
 375         wpa_printf(MSG_DEBUG, "EAP-EKE: Received EAP-EKE-Commit/Request");
 376
 377         password = eap_get_config_password(sm, &password_len);
 378         if (password == NULL) {
 379                 wpa_printf(MSG_INFO, "EAP-EKE: No password configured!");
 380                 return eap_eke_build_fail(data, ret, id,
 381                                           EAP_EKE_FAIL_PASSWD_NOT_FOUND);
 382         }
 383
 384         pos = payload;
 385         end = payload + payload_len;
 386
 387         if (pos + data->sess.dhcomp_len > end) {
 388                 wpa_printf(MSG_DEBUG, "EAP-EKE: Too short EAP-EKE-Commit");
 389                 return eap_eke_build_fail(data, ret, id,
 390                                           EAP_EKE_FAIL_PROTO_ERROR);
 391         }
 392
 393         wpa_hexdump(MSG_DEBUG, "EAP-EKE: DHComponent_S",
 394                     pos, data->sess.dhcomp_len);
 395         dhcomp = pos;
 396         pos += data->sess.dhcomp_len;
 397         wpa_hexdump(MSG_DEBUG, "EAP-EKE: CBValue", pos, end - pos);
 398
 399         /*
 400          * temp = prf(0+, password)
 401          * key = prf+(temp, ID_S | ID_P)
 402          */
 403         if (eap_eke_derive_key(&data->sess, password, password_len,
 404                                data->serverid, data->serverid_len,
 405                                data->peerid, data->peerid_len, key) < 0) {
 406                 wpa_printf(MSG_INFO, "EAP-EKE: Failed to derive key");
 407                 return eap_eke_build_fail(data, ret, id,
 408                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 409         }
 410
 411         /*
 412          * y_p = g ^ x_p (mod p)
 413          * x_p = random number 2 .. p-1
 414          */
 415         if (eap_eke_dh_init(data->sess.dhgroup, data->dh_priv, pub) < 0) {
 416                 wpa_printf(MSG_INFO, "EAP-EKE: Failed to initialize DH");
 417                 os_memset(key, 0, sizeof(key));
 418                 return eap_eke_build_fail(data, ret, id,
 419                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 420         }
 421
 422         if (eap_eke_shared_secret(&data->sess, key, data->dh_priv, dhcomp) < 0)
 423         {
 424                 wpa_printf(MSG_INFO, "EAP-EKE: Failed to derive shared secret");
 425                 os_memset(key, 0, sizeof(key));
 426                 return eap_eke_build_fail(data, ret, id,
 427                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 428         }
 429
 430         if (eap_eke_derive_ke_ki(&data->sess,
 431                                  data->serverid, data->serverid_len,
 432                                  data->peerid, data->peerid_len) < 0) {
 433                 wpa_printf(MSG_INFO, "EAP-EKE: Failed to derive Ke/Ki");
 434                 os_memset(key, 0, sizeof(key));
 435                 return eap_eke_build_fail(data, ret, id,
 436                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 437         }
 438
 439         wpa_printf(MSG_DEBUG, "EAP-EKE: Sending EAP-EKE-Commit/Response");
 440
 441         resp = eap_eke_build_msg(data, id,
 442                                  data->sess.dhcomp_len + data->sess.pnonce_len,
 443                                  EAP_EKE_COMMIT);
 444         if (resp == NULL) {
 445                 os_memset(key, 0, sizeof(key));
 446                 return eap_eke_build_fail(data, ret, id,
 447                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 448         }
 449
 450         /* DHComponent_P = Encr(key, y_p) */
 451         rpos = wpabuf_put(resp, data->sess.dhcomp_len);
 452         if (eap_eke_dhcomp(&data->sess, key, pub, rpos) < 0) {
 453                 wpabuf_free(resp);
 454                 wpa_printf(MSG_INFO, "EAP-EKE: Failed to build DHComponent_P");
 455                 os_memset(key, 0, sizeof(key));
 456                 return eap_eke_build_fail(data, ret, id,
 457                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 458         }
 459         os_memset(key, 0, sizeof(key));
 460
 461         wpa_hexdump(MSG_DEBUG, "EAP-EKE: DHComponent_P",
 462                     rpos, data->sess.dhcomp_len);
 463
 464         if (random_get_bytes(data->nonce_p, data->sess.nonce_len)) {
 465                 wpabuf_free(resp);
 466                 return eap_eke_build_fail(data, ret, id,
 467                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 468         }
 469         wpa_hexdump_key(MSG_DEBUG, "EAP-EKE: Nonce_P",
 470                         data->nonce_p, data->sess.nonce_len);
 471         prot_len = wpabuf_tailroom(resp);
 472         if (eap_eke_prot(&data->sess, data->nonce_p, data->sess.nonce_len,
 473                          wpabuf_put(resp, 0), &prot_len) < 0) {
 474                 wpabuf_free(resp);
 475                 return eap_eke_build_fail(data, ret, id,
 476                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 477         }
 478         wpa_hexdump(MSG_DEBUG, "EAP-EKE: PNonce_P",
 479                     wpabuf_put(resp, 0), prot_len);
 480         wpabuf_put(resp, prot_len);
 481
 482         /* TODO: CBValue */
 483
 484         if (wpabuf_resize(&data->msgs, wpabuf_len(reqData) + wpabuf_len(resp))
 485             < 0) {
 486                 wpabuf_free(resp);
 487                 return eap_eke_build_fail(data, ret, id,
 488                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 489         }
 490         wpabuf_put_buf(data->msgs, reqData);
 491         wpabuf_put_buf(data->msgs, resp);
 492
 493         eap_eke_state(data, CONFIRM);
 494
 495         return resp;
 496 }
 497
 498
 499 static struct wpabuf * eap_eke_process_confirm(struct eap_eke_data *data,
 500                                                struct eap_method_ret *ret,
 501                                                const struct wpabuf *reqData,
 502                                                const u8 *payload,
 503                                                size_t payload_len)
 504 {
 505         struct wpabuf *resp;
 506         const u8 *pos, *end;
 507         size_t prot_len;
 508         u8 nonces[2 * EAP_EKE_MAX_NONCE_LEN];
 509         u8 auth_s[EAP_EKE_MAX_HASH_LEN];
 510         size_t decrypt_len;
 511         u8 *auth;
 512         u8 id = eap_get_id(reqData);
 513
 514         if (data->state != CONFIRM) {
 515                 wpa_printf(MSG_DEBUG, "EAP-EKE: EAP-EKE-Confirm/Request received in unexpected state (%d)",
 516                            data->state);
 517                 return eap_eke_build_fail(data, ret, id,
 518                                           EAP_EKE_FAIL_PROTO_ERROR);
 519         }
 520
 521         wpa_printf(MSG_DEBUG, "EAP-EKE: Received EAP-EKE-Confirm/Request");
 522
 523         pos = payload;
 524         end = payload + payload_len;
 525
 526         if (pos + data->sess.pnonce_ps_len + data->sess.prf_len > end) {
 527                 wpa_printf(MSG_DEBUG, "EAP-EKE: Too short EAP-EKE-Confirm");
 528                 return eap_eke_build_fail(data, ret, id,
 529                                           EAP_EKE_FAIL_PROTO_ERROR);
 530         }
 531
 532         decrypt_len = sizeof(nonces);
 533         if (eap_eke_decrypt_prot(&data->sess, pos, data->sess.pnonce_ps_len,
 534                                  nonces, &decrypt_len) < 0) {
 535                 wpa_printf(MSG_INFO, "EAP-EKE: Failed to decrypt PNonce_PS");
 536                 return eap_eke_build_fail(data, ret, id,
 537                                           EAP_EKE_FAIL_AUTHENTICATION_FAIL);
 538         }
 539         if (decrypt_len != (size_t) 2 * data->sess.nonce_len) {
 540                 wpa_printf(MSG_INFO, "EAP-EKE: PNonce_PS protected data length does not match length of Nonce_P and Nonce_S");
 541                 return eap_eke_build_fail(data, ret, id,
 542                                           EAP_EKE_FAIL_AUTHENTICATION_FAIL);
 543         }
 544         wpa_hexdump_key(MSG_DEBUG, "EAP-EKE: Received Nonce_P | Nonce_S",
 545                         nonces, 2 * data->sess.nonce_len);
 546         if (os_memcmp(data->nonce_p, nonces, data->sess.nonce_len) != 0) {
 547                 wpa_printf(MSG_INFO, "EAP-EKE: Received Nonce_P does not match transmitted Nonce_P");
 548                 return eap_eke_build_fail(data, ret, id,
 549                                           EAP_EKE_FAIL_AUTHENTICATION_FAIL);
 550         }
 551
 552         os_memcpy(data->nonce_s, nonces + data->sess.nonce_len,
 553                   data->sess.nonce_len);
 554         wpa_hexdump_key(MSG_DEBUG, "EAP-EKE: Nonce_S",
 555                         data->nonce_s, data->sess.nonce_len);
 556
 557         if (eap_eke_derive_ka(&data->sess, data->serverid, data->serverid_len,
 558                               data->peerid, data->peerid_len,
 559                               data->nonce_p, data->nonce_s) < 0) {
 560                 return eap_eke_build_fail(data, ret, id,
 561                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 562         }
 563
 564         if (eap_eke_auth(&data->sess, "EAP-EKE server", data->msgs, auth_s) < 0)
 565         {
 566                 return eap_eke_build_fail(data, ret, id,
 567                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 568         }
 569         wpa_hexdump(MSG_DEBUG, "EAP-EKE: Auth_S", auth_s, data->sess.prf_len);
 570         if (os_memcmp_const(auth_s, pos + data->sess.pnonce_ps_len,
 571                             data->sess.prf_len) != 0) {
 572                 wpa_printf(MSG_INFO, "EAP-EKE: Auth_S does not match");
 573                 return eap_eke_build_fail(data, ret, id,
 574                                           EAP_EKE_FAIL_AUTHENTICATION_FAIL);
 575         }
 576
 577         wpa_printf(MSG_DEBUG, "EAP-EKE: Sending EAP-EKE-Confirm/Response");
 578
 579         resp = eap_eke_build_msg(data, id,
 580                                  data->sess.pnonce_len + data->sess.prf_len,
 581                                  EAP_EKE_CONFIRM);
 582         if (resp == NULL) {
 583                 return eap_eke_build_fail(data, ret, id,
 584                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 585         }
 586
 587         prot_len = wpabuf_tailroom(resp);
 588         if (eap_eke_prot(&data->sess, data->nonce_s, data->sess.nonce_len,
 589                          wpabuf_put(resp, 0), &prot_len) < 0) {
 590                 wpabuf_free(resp);
 591                 return eap_eke_build_fail(data, ret, id,
 592                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 593         }
 594         wpabuf_put(resp, prot_len);
 595
 596         auth = wpabuf_put(resp, data->sess.prf_len);
 597         if (eap_eke_auth(&data->sess, "EAP-EKE peer", data->msgs, auth) < 0) {
 598                 wpabuf_free(resp);
 599                 return eap_eke_build_fail(data, ret, id,
 600                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 601         }
 602         wpa_hexdump(MSG_DEBUG, "EAP-EKE: Auth_P", auth, data->sess.prf_len);
 603
 604         if (eap_eke_derive_msk(&data->sess, data->serverid, data->serverid_len,
 605                                data->peerid, data->peerid_len,
 606                                data->nonce_s, data->nonce_p,
 607                                data->msk, data->emsk) < 0) {
 608                 wpa_printf(MSG_INFO, "EAP-EKE: Failed to derive MSK/EMSK");
 609                 wpabuf_free(resp);
 610                 return eap_eke_build_fail(data, ret, id,
 611                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 612         }
 613
 614         os_memset(data->dh_priv, 0, sizeof(data->dh_priv));
 615         eap_eke_session_clean(&data->sess);
 616
 617         eap_eke_state(data, SUCCESS);
 618         ret->methodState = METHOD_MAY_CONT;
 619         ret->decision = DECISION_COND_SUCC;
 620         ret->allowNotifications = FALSE;
 621
 622         return resp;
 623 }
 624
 625
 626 static struct wpabuf * eap_eke_process_failure(struct eap_eke_data *data,
 627                                                struct eap_method_ret *ret,
 628                                                const struct wpabuf *reqData,
 629                                                const u8 *payload,
 630                                                size_t payload_len)
 631 {
 632         wpa_printf(MSG_DEBUG, "EAP-EKE: Received EAP-EKE-Failure/Request");
 633
 634         if (payload_len < 4) {
 635                 wpa_printf(MSG_DEBUG, "EAP-EKE: Too short EAP-EKE-Failure");
 636         } else {
 637                 u32 code;
 638                 code = WPA_GET_BE32(payload);
 639                 wpa_printf(MSG_INFO, "EAP-EKE: Failure-Code 0x%x", code);
 640         }
 641
 642         return eap_eke_build_fail(data, ret, eap_get_id(reqData),
 643                                   EAP_EKE_FAIL_NO_ERROR);
 644 }
 645
 646
 647 static struct wpabuf * eap_eke_process(struct eap_sm *sm, void *priv,
 648                                        struct eap_method_ret *ret,
 649                                        const struct wpabuf *reqData)
 650 {
 651         struct eap_eke_data *data = priv;
 652         struct wpabuf *resp;
 653         const u8 *pos, *end;
 654         size_t len;
 655         u8 eke_exch;
 656
 657         pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_EKE, reqData, &len);
 658         if (pos == NULL || len < 1) {
 659                 ret->ignore = TRUE;
 660                 return NULL;
 661         }
 662
 663         end = pos + len;
 664         eke_exch = *pos++;
 665
 666         wpa_printf(MSG_DEBUG, "EAP-EKE: Received frame: exch %d", eke_exch);
 667         wpa_hexdump(MSG_DEBUG, "EAP-EKE: Received Data", pos, end - pos);
 668
 669         ret->ignore = FALSE;
 670         ret->methodState = METHOD_MAY_CONT;
 671         ret->decision = DECISION_FAIL;
 672         ret->allowNotifications = TRUE;
 673
 674         switch (eke_exch) {
 675         case EAP_EKE_ID:
 676                 resp = eap_eke_process_id(data, ret, reqData, pos, end - pos);
 677                 break;
 678         case EAP_EKE_COMMIT:
 679                 resp = eap_eke_process_commit(sm, data, ret, reqData,
 680                                               pos, end - pos);
 681                 break;
 682         case EAP_EKE_CONFIRM:
 683                 resp = eap_eke_process_confirm(data, ret, reqData,
 684                                                pos, end - pos);
 685                 break;
 686         case EAP_EKE_FAILURE:
 687                 resp = eap_eke_process_failure(data, ret, reqData,
 688                                                pos, end - pos);
 689                 break;
 690         default:
 691                 wpa_printf(MSG_DEBUG, "EAP-EKE: Ignoring message with unknown EKE-Exch %d", eke_exch);
 692                 ret->ignore = TRUE;
 693                 return NULL;
 694         }
 695
 696         if (ret->methodState == METHOD_DONE)
 697                 ret->allowNotifications = FALSE;
 698
 699         return resp;
 700 }
 701
 702
 703 static Boolean eap_eke_isKeyAvailable(struct eap_sm *sm, void *priv)
 704 {
 705         struct eap_eke_data *data = priv;
 706         return data->state == SUCCESS;
 707 }
 708
 709
 710 static u8 * eap_eke_getKey(struct eap_sm *sm, void *priv, size_t *len)
 711 {
 712         struct eap_eke_data *data = priv;
 713         u8 *key;
 714
 715         if (data->state != SUCCESS)
 716                 return NULL;
 717
 718         key = os_memdup(data->msk, EAP_MSK_LEN);
 719         if (key == NULL)
 720                 return NULL;
 721         *len = EAP_MSK_LEN;
 722
 723         return key;
 724 }
 725
 726
 727 static u8 * eap_eke_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
 728 {
 729         struct eap_eke_data *data = priv;
 730         u8 *key;
 731
 732         if (data->state != SUCCESS)
 733                 return NULL;
 734
 735         key = os_memdup(data->emsk, EAP_EMSK_LEN);
 736         if (key == NULL)
 737                 return NULL;
 738         *len = EAP_EMSK_LEN;
 739
 740         return key;
 741 }
 742
 743
 744 static u8 * eap_eke_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
 745 {
 746         struct eap_eke_data *data = priv;
 747         u8 *sid;
 748         size_t sid_len;
 749
 750         if (data->state != SUCCESS)
 751                 return NULL;
 752
 753         sid_len = 1 + 2 * data->sess.nonce_len;
 754         sid = os_malloc(sid_len);
 755         if (sid == NULL)
 756                 return NULL;
 757         sid[0] = EAP_TYPE_EKE;
 758         os_memcpy(sid + 1, data->nonce_p, data->sess.nonce_len);
 759         os_memcpy(sid + 1 + data->sess.nonce_len, data->nonce_s,
 760                   data->sess.nonce_len);
 761         *len = sid_len;
 762
 763         return sid;
 764 }
 765
 766
 767 int eap_peer_eke_register(void)
 768 {
 769         struct eap_method *eap;
 770
 771         eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
 772                                     EAP_VENDOR_IETF, EAP_TYPE_EKE, "EKE");
 773         if (eap == NULL)
 774                 return -1;
 775
 776         eap->init = eap_eke_init;
 777         eap->deinit = eap_eke_deinit;
 778         eap->process = eap_eke_process;
 779         eap->isKeyAvailable = eap_eke_isKeyAvailable;
 780         eap->getKey = eap_eke_getKey;
 781         eap->get_emsk = eap_eke_get_emsk;
 782         eap->getSessionId = eap_eke_get_session_id;
 783
 784         return eap_peer_method_register(eap);
 785 }