libeap/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_malloc(identity_len);
  89                 if (data->peerid == NULL) {
  90                         eap_eke_deinit(sm, data);
  91                         return NULL;
  92                 }
  93                 os_memcpy(data->peerid, identity, identity_len);
  94                 data->peerid_len = identity_len;
  95         }
  96
  97         phase1 = eap_get_config_phase1(sm);
  98         if (phase1) {
  99                 const char *pos;
 100
 101                 pos = os_strstr(phase1, "dhgroup=");
 102                 if (pos) {
 103                         data->dhgroup = atoi(pos + 8);
 104                         wpa_printf(MSG_DEBUG, "EAP-EKE: Forced dhgroup %u",
 105                                    data->dhgroup);
 106                 }
 107
 108                 pos = os_strstr(phase1, "encr=");
 109                 if (pos) {
 110                         data->encr = atoi(pos + 5);
 111                         wpa_printf(MSG_DEBUG, "EAP-EKE: Forced encr %u",
 112                                    data->encr);
 113                 }
 114
 115                 pos = os_strstr(phase1, "prf=");
 116                 if (pos) {
 117                         data->prf = atoi(pos + 4);
 118                         wpa_printf(MSG_DEBUG, "EAP-EKE: Forced prf %u",
 119                                    data->prf);
 120                 }
 121
 122                 pos = os_strstr(phase1, "mac=");
 123                 if (pos) {
 124                         data->mac = atoi(pos + 4);
 125                         wpa_printf(MSG_DEBUG, "EAP-EKE: Forced mac %u",
 126                                    data->mac);
 127                 }
 128         }
 129
 130         return data;
 131 }
 132
 133
 134 static void eap_eke_deinit(struct eap_sm *sm, void *priv)
 135 {
 136         struct eap_eke_data *data = priv;
 137         eap_eke_session_clean(&data->sess);
 138         os_free(data->serverid);
 139         os_free(data->peerid);
 140         wpabuf_free(data->msgs);
 141         bin_clear_free(data, sizeof(*data));
 142 }
 143
 144
 145 static struct wpabuf * eap_eke_build_msg(struct eap_eke_data *data, int id,
 146                                          size_t length, u8 eke_exch)
 147 {
 148         struct wpabuf *msg;
 149         size_t plen;
 150
 151         plen = 1 + length;
 152
 153         msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_EKE, plen,
 154                             EAP_CODE_RESPONSE, id);
 155         if (msg == NULL) {
 156                 wpa_printf(MSG_ERROR, "EAP-EKE: Failed to allocate memory");
 157                 return NULL;
 158         }
 159
 160         wpabuf_put_u8(msg, eke_exch);
 161
 162         return msg;
 163 }
 164
 165
 166 static int eap_eke_supp_dhgroup(u8 dhgroup)
 167 {
 168         return dhgroup == EAP_EKE_DHGROUP_EKE_2 ||
 169                 dhgroup == EAP_EKE_DHGROUP_EKE_5 ||
 170                 dhgroup == EAP_EKE_DHGROUP_EKE_14 ||
 171                 dhgroup == EAP_EKE_DHGROUP_EKE_15 ||
 172                 dhgroup == EAP_EKE_DHGROUP_EKE_16;
 173 }
 174
 175
 176 static int eap_eke_supp_encr(u8 encr)
 177 {
 178         return encr == EAP_EKE_ENCR_AES128_CBC;
 179 }
 180
 181
 182 static int eap_eke_supp_prf(u8 prf)
 183 {
 184         return prf == EAP_EKE_PRF_HMAC_SHA1 ||
 185                 prf == EAP_EKE_PRF_HMAC_SHA2_256;
 186 }
 187
 188
 189 static int eap_eke_supp_mac(u8 mac)
 190 {
 191         return mac == EAP_EKE_MAC_HMAC_SHA1 ||
 192                 mac == EAP_EKE_MAC_HMAC_SHA2_256;
 193 }
 194
 195
 196 static struct wpabuf * eap_eke_build_fail(struct eap_eke_data *data,
 197                                           struct eap_method_ret *ret,
 198                                           u8 id, u32 failure_code)
 199 {
 200         struct wpabuf *resp;
 201
 202         wpa_printf(MSG_DEBUG, "EAP-EKE: Sending EAP-EKE-Failure/Response - code=0x%x",
 203                    failure_code);
 204
 205         resp = eap_eke_build_msg(data, id, 4, EAP_EKE_FAILURE);
 206         if (resp)
 207                 wpabuf_put_be32(resp, failure_code);
 208
 209         os_memset(data->dh_priv, 0, sizeof(data->dh_priv));
 210         eap_eke_session_clean(&data->sess);
 211
 212         eap_eke_state(data, FAILURE);
 213         ret->methodState = METHOD_DONE;
 214         ret->decision = DECISION_FAIL;
 215         ret->allowNotifications = FALSE;
 216
 217         return resp;
 218 }
 219
 220
 221 static struct wpabuf * eap_eke_process_id(struct eap_eke_data *data,
 222                                           struct eap_method_ret *ret,
 223                                           const struct wpabuf *reqData,
 224                                           const u8 *payload,
 225                                           size_t payload_len)
 226 {
 227         struct wpabuf *resp;
 228         unsigned num_prop, i;
 229         const u8 *pos, *end;
 230         const u8 *prop = NULL;
 231         u8 idtype;
 232         u8 id = eap_get_id(reqData);
 233
 234         if (data->state != IDENTITY) {
 235                 return eap_eke_build_fail(data, ret, id,
 236                                           EAP_EKE_FAIL_PROTO_ERROR);
 237         }
 238
 239         wpa_printf(MSG_DEBUG, "EAP-EKE: Received EAP-EKE-ID/Request");
 240
 241         if (payload_len < 2 + 4) {
 242                 wpa_printf(MSG_DEBUG, "EAP-EKE: Too short ID/Request Data");
 243                 return eap_eke_build_fail(data, ret, id,
 244                                           EAP_EKE_FAIL_PROTO_ERROR);
 245         }
 246
 247         pos = payload;
 248         end = payload + payload_len;
 249
 250         num_prop = *pos++;
 251         pos++; /* Ignore Reserved field */
 252
 253         if (pos + num_prop * 4 > end) {
 254                 wpa_printf(MSG_DEBUG, "EAP-EKE: Too short ID/Request Data (num_prop=%u)",
 255                            num_prop);
 256                 return eap_eke_build_fail(data, ret, id,
 257                                           EAP_EKE_FAIL_PROTO_ERROR);
 258         }
 259
 260         for (i = 0; i < num_prop; i++) {
 261                 const u8 *tmp = pos;
 262
 263                 wpa_printf(MSG_DEBUG, "EAP-EKE: Proposal #%u: dh=%u encr=%u prf=%u mac=%u",
 264                            i, pos[0], pos[1], pos[2], pos[3]);
 265                 pos += 4;
 266
 267                 if ((data->dhgroup && data->dhgroup != *tmp) ||
 268                     !eap_eke_supp_dhgroup(*tmp))
 269                         continue;
 270                 tmp++;
 271                 if ((data->encr && data->encr != *tmp) ||
 272                     !eap_eke_supp_encr(*tmp))
 273                         continue;
 274                 tmp++;
 275                 if ((data->prf && data->prf != *tmp) ||
 276                     !eap_eke_supp_prf(*tmp))
 277                         continue;
 278                 tmp++;
 279                 if ((data->mac && data->mac != *tmp) ||
 280                     !eap_eke_supp_mac(*tmp))
 281                         continue;
 282
 283                 prop = tmp - 3;
 284                 if (eap_eke_session_init(&data->sess, prop[0], prop[1], prop[2],
 285                                          prop[3]) < 0) {
 286                         prop = NULL;
 287                         continue;
 288                 }
 289
 290                 wpa_printf(MSG_DEBUG, "EAP-EKE: Selected proposal");
 291                 break;
 292         }
 293
 294         if (prop == NULL) {
 295                 wpa_printf(MSG_DEBUG, "EAP-EKE: No acceptable proposal found");
 296                 return eap_eke_build_fail(data, ret, id,
 297                                           EAP_EKE_FAIL_NO_PROPOSAL_CHOSEN);
 298         }
 299
 300         pos += (num_prop - i - 1) * 4;
 301
 302         if (pos == end) {
 303                 wpa_printf(MSG_DEBUG, "EAP-EKE: Too short ID/Request Data to include IDType/Identity");
 304                 return eap_eke_build_fail(data, ret, id,
 305                                           EAP_EKE_FAIL_PROTO_ERROR);
 306         }
 307
 308         idtype = *pos++;
 309         wpa_printf(MSG_DEBUG, "EAP-EKE: Server IDType %u", idtype);
 310         wpa_hexdump_ascii(MSG_DEBUG, "EAP-EKE: Server Identity",
 311                           pos, end - pos);
 312         os_free(data->serverid);
 313         data->serverid = os_malloc(end - pos);
 314         if (data->serverid == NULL) {
 315                 return eap_eke_build_fail(data, ret, id,
 316                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 317         }
 318         os_memcpy(data->serverid, pos, end - pos);
 319         data->serverid_len = end - pos;
 320
 321         wpa_printf(MSG_DEBUG, "EAP-EKE: Sending EAP-EKE-ID/Response");
 322
 323         resp = eap_eke_build_msg(data, id,
 324                                  2 + 4 + 1 + data->peerid_len,
 325                                  EAP_EKE_ID);
 326         if (resp == NULL) {
 327                 return eap_eke_build_fail(data, ret, id,
 328                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 329         }
 330
 331         wpabuf_put_u8(resp, 1); /* NumProposals */
 332         wpabuf_put_u8(resp, 0); /* Reserved */
 333         wpabuf_put_data(resp, prop, 4); /* Selected Proposal */
 334         wpabuf_put_u8(resp, EAP_EKE_ID_NAI);
 335         if (data->peerid)
 336                 wpabuf_put_data(resp, data->peerid, data->peerid_len);
 337
 338         wpabuf_free(data->msgs);
 339         data->msgs = wpabuf_alloc(wpabuf_len(reqData) + wpabuf_len(resp));
 340         if (data->msgs == NULL) {
 341                 wpabuf_free(resp);
 342                 return eap_eke_build_fail(data, ret, id,
 343                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 344         }
 345         wpabuf_put_buf(data->msgs, reqData);
 346         wpabuf_put_buf(data->msgs, resp);
 347
 348         eap_eke_state(data, COMMIT);
 349
 350         return resp;
 351 }
 352
 353
 354 static struct wpabuf * eap_eke_process_commit(struct eap_sm *sm,
 355                                               struct eap_eke_data *data,
 356                                               struct eap_method_ret *ret,
 357                                               const struct wpabuf *reqData,
 358                                               const u8 *payload,
 359                                               size_t payload_len)
 360 {
 361         struct wpabuf *resp;
 362         const u8 *pos, *end, *dhcomp;
 363         size_t prot_len;
 364         u8 *rpos;
 365         u8 key[EAP_EKE_MAX_KEY_LEN];
 366         u8 pub[EAP_EKE_MAX_DH_LEN];
 367         const u8 *password;
 368         size_t password_len;
 369         u8 id = eap_get_id(reqData);
 370
 371         if (data->state != COMMIT) {
 372                 wpa_printf(MSG_DEBUG, "EAP-EKE: EAP-EKE-Commit/Request received in unexpected state (%d)", data->state);
 373                 return eap_eke_build_fail(data, ret, id,
 374                                           EAP_EKE_FAIL_PROTO_ERROR);
 375         }
 376
 377         wpa_printf(MSG_DEBUG, "EAP-EKE: Received EAP-EKE-Commit/Request");
 378
 379         password = eap_get_config_password(sm, &password_len);
 380         if (password == NULL) {
 381                 wpa_printf(MSG_INFO, "EAP-EKE: No password configured!");
 382                 return eap_eke_build_fail(data, ret, id,
 383                                           EAP_EKE_FAIL_PASSWD_NOT_FOUND);
 384         }
 385
 386         pos = payload;
 387         end = payload + payload_len;
 388
 389         if (pos + data->sess.dhcomp_len > end) {
 390                 wpa_printf(MSG_DEBUG, "EAP-EKE: Too short EAP-EKE-Commit");
 391                 return eap_eke_build_fail(data, ret, id,
 392                                           EAP_EKE_FAIL_PROTO_ERROR);
 393         }
 394
 395         wpa_hexdump(MSG_DEBUG, "EAP-EKE: DHComponent_S",
 396                     pos, data->sess.dhcomp_len);
 397         dhcomp = pos;
 398         pos += data->sess.dhcomp_len;
 399         wpa_hexdump(MSG_DEBUG, "EAP-EKE: CBValue", pos, end - pos);
 400
 401         /*
 402          * temp = prf(0+, password)
 403          * key = prf+(temp, ID_S | ID_P)
 404          */
 405         if (eap_eke_derive_key(&data->sess, password, password_len,
 406                                data->serverid, data->serverid_len,
 407                                data->peerid, data->peerid_len, key) < 0) {
 408                 wpa_printf(MSG_INFO, "EAP-EKE: Failed to derive key");
 409                 return eap_eke_build_fail(data, ret, id,
 410                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 411         }
 412
 413         /*
 414          * y_p = g ^ x_p (mod p)
 415          * x_p = random number 2 .. p-1
 416          */
 417         if (eap_eke_dh_init(data->sess.dhgroup, data->dh_priv, pub) < 0) {
 418                 wpa_printf(MSG_INFO, "EAP-EKE: Failed to initialize DH");
 419                 os_memset(key, 0, sizeof(key));
 420                 return eap_eke_build_fail(data, ret, id,
 421                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 422         }
 423
 424         if (eap_eke_shared_secret(&data->sess, key, data->dh_priv, dhcomp) < 0)
 425         {
 426                 wpa_printf(MSG_INFO, "EAP-EKE: Failed to derive shared secret");
 427                 os_memset(key, 0, sizeof(key));
 428                 return eap_eke_build_fail(data, ret, id,
 429                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 430         }
 431
 432         if (eap_eke_derive_ke_ki(&data->sess,
 433                                  data->serverid, data->serverid_len,
 434                                  data->peerid, data->peerid_len) < 0) {
 435                 wpa_printf(MSG_INFO, "EAP-EKE: Failed to derive Ke/Ki");
 436                 os_memset(key, 0, sizeof(key));
 437                 return eap_eke_build_fail(data, ret, id,
 438                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 439         }
 440
 441         wpa_printf(MSG_DEBUG, "EAP-EKE: Sending EAP-EKE-Commit/Response");
 442
 443         resp = eap_eke_build_msg(data, id,
 444                                  data->sess.dhcomp_len + data->sess.pnonce_len,
 445                                  EAP_EKE_COMMIT);
 446         if (resp == NULL) {
 447                 os_memset(key, 0, sizeof(key));
 448                 return eap_eke_build_fail(data, ret, id,
 449                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 450         }
 451
 452         /* DHComponent_P = Encr(key, y_p) */
 453         rpos = wpabuf_put(resp, data->sess.dhcomp_len);
 454         if (eap_eke_dhcomp(&data->sess, key, pub, rpos) < 0) {
 455                 wpabuf_free(resp);
 456                 wpa_printf(MSG_INFO, "EAP-EKE: Failed to build DHComponent_P");
 457                 os_memset(key, 0, sizeof(key));
 458                 return eap_eke_build_fail(data, ret, id,
 459                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 460         }
 461         os_memset(key, 0, sizeof(key));
 462
 463         wpa_hexdump(MSG_DEBUG, "EAP-EKE: DHComponent_P",
 464                     rpos, data->sess.dhcomp_len);
 465
 466         if (random_get_bytes(data->nonce_p, data->sess.nonce_len)) {
 467                 wpabuf_free(resp);
 468                 return eap_eke_build_fail(data, ret, id,
 469                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 470         }
 471         wpa_hexdump_key(MSG_DEBUG, "EAP-EKE: Nonce_P",
 472                         data->nonce_p, data->sess.nonce_len);
 473         prot_len = wpabuf_tailroom(resp);
 474         if (eap_eke_prot(&data->sess, data->nonce_p, data->sess.nonce_len,
 475                          wpabuf_put(resp, 0), &prot_len) < 0) {
 476                 wpabuf_free(resp);
 477                 return eap_eke_build_fail(data, ret, id,
 478                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 479         }
 480         wpa_hexdump(MSG_DEBUG, "EAP-EKE: PNonce_P",
 481                     wpabuf_put(resp, 0), prot_len);
 482         wpabuf_put(resp, prot_len);
 483
 484         /* TODO: CBValue */
 485
 486         if (wpabuf_resize(&data->msgs, wpabuf_len(reqData) + wpabuf_len(resp))
 487             < 0) {
 488                 wpabuf_free(resp);
 489                 return eap_eke_build_fail(data, ret, id,
 490                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 491         }
 492         wpabuf_put_buf(data->msgs, reqData);
 493         wpabuf_put_buf(data->msgs, resp);
 494
 495         eap_eke_state(data, CONFIRM);
 496
 497         return resp;
 498 }
 499
 500
 501 static struct wpabuf * eap_eke_process_confirm(struct eap_eke_data *data,
 502                                                struct eap_method_ret *ret,
 503                                                const struct wpabuf *reqData,
 504                                                const u8 *payload,
 505                                                size_t payload_len)
 506 {
 507         struct wpabuf *resp;
 508         const u8 *pos, *end;
 509         size_t prot_len;
 510         u8 nonces[2 * EAP_EKE_MAX_NONCE_LEN];
 511         u8 auth_s[EAP_EKE_MAX_HASH_LEN];
 512         size_t decrypt_len;
 513         u8 *auth;
 514         u8 id = eap_get_id(reqData);
 515
 516         if (data->state != CONFIRM) {
 517                 wpa_printf(MSG_DEBUG, "EAP-EKE: EAP-EKE-Confirm/Request received in unexpected state (%d)",
 518                            data->state);
 519                 return eap_eke_build_fail(data, ret, id,
 520                                           EAP_EKE_FAIL_PROTO_ERROR);
 521         }
 522
 523         wpa_printf(MSG_DEBUG, "EAP-EKE: Received EAP-EKE-Confirm/Request");
 524
 525         pos = payload;
 526         end = payload + payload_len;
 527
 528         if (pos + data->sess.pnonce_ps_len + data->sess.prf_len > end) {
 529                 wpa_printf(MSG_DEBUG, "EAP-EKE: Too short EAP-EKE-Confirm");
 530                 return eap_eke_build_fail(data, ret, id,
 531                                           EAP_EKE_FAIL_PROTO_ERROR);
 532         }
 533
 534         decrypt_len = sizeof(nonces);
 535         if (eap_eke_decrypt_prot(&data->sess, pos, data->sess.pnonce_ps_len,
 536                                  nonces, &decrypt_len) < 0) {
 537                 wpa_printf(MSG_INFO, "EAP-EKE: Failed to decrypt PNonce_PS");
 538                 return eap_eke_build_fail(data, ret, id,
 539                                           EAP_EKE_FAIL_AUTHENTICATION_FAIL);
 540         }
 541         if (decrypt_len != (size_t) 2 * data->sess.nonce_len) {
 542                 wpa_printf(MSG_INFO, "EAP-EKE: PNonce_PS protected data length does not match length of Nonce_P and Nonce_S");
 543                 return eap_eke_build_fail(data, ret, id,
 544                                           EAP_EKE_FAIL_AUTHENTICATION_FAIL);
 545         }
 546         wpa_hexdump_key(MSG_DEBUG, "EAP-EKE: Received Nonce_P | Nonce_S",
 547                         nonces, 2 * data->sess.nonce_len);
 548         if (os_memcmp(data->nonce_p, nonces, data->sess.nonce_len) != 0) {
 549                 wpa_printf(MSG_INFO, "EAP-EKE: Received Nonce_P does not match transmitted Nonce_P");
 550                 return eap_eke_build_fail(data, ret, id,
 551                                           EAP_EKE_FAIL_AUTHENTICATION_FAIL);
 552         }
 553
 554         os_memcpy(data->nonce_s, nonces + data->sess.nonce_len,
 555                   data->sess.nonce_len);
 556         wpa_hexdump_key(MSG_DEBUG, "EAP-EKE: Nonce_S",
 557                         data->nonce_s, data->sess.nonce_len);
 558
 559         if (eap_eke_derive_ka(&data->sess, data->serverid, data->serverid_len,
 560                               data->peerid, data->peerid_len,
 561                               data->nonce_p, data->nonce_s) < 0) {
 562                 return eap_eke_build_fail(data, ret, id,
 563                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 564         }
 565
 566         if (eap_eke_auth(&data->sess, "EAP-EKE server", data->msgs, auth_s) < 0)
 567         {
 568                 return eap_eke_build_fail(data, ret, id,
 569                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 570         }
 571         wpa_hexdump(MSG_DEBUG, "EAP-EKE: Auth_S", auth_s, data->sess.prf_len);
 572         if (os_memcmp_const(auth_s, pos + data->sess.pnonce_ps_len,
 573                             data->sess.prf_len) != 0) {
 574                 wpa_printf(MSG_INFO, "EAP-EKE: Auth_S does not match");
 575                 return eap_eke_build_fail(data, ret, id,
 576                                           EAP_EKE_FAIL_AUTHENTICATION_FAIL);
 577         }
 578
 579         wpa_printf(MSG_DEBUG, "EAP-EKE: Sending EAP-EKE-Confirm/Response");
 580
 581         resp = eap_eke_build_msg(data, id,
 582                                  data->sess.pnonce_len + data->sess.prf_len,
 583                                  EAP_EKE_CONFIRM);
 584         if (resp == NULL) {
 585                 return eap_eke_build_fail(data, ret, id,
 586                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 587         }
 588
 589         prot_len = wpabuf_tailroom(resp);
 590         if (eap_eke_prot(&data->sess, data->nonce_s, data->sess.nonce_len,
 591                          wpabuf_put(resp, 0), &prot_len) < 0) {
 592                 wpabuf_free(resp);
 593                 return eap_eke_build_fail(data, ret, id,
 594                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 595         }
 596         wpabuf_put(resp, prot_len);
 597
 598         auth = wpabuf_put(resp, data->sess.prf_len);
 599         if (eap_eke_auth(&data->sess, "EAP-EKE peer", data->msgs, auth) < 0) {
 600                 wpabuf_free(resp);
 601                 return eap_eke_build_fail(data, ret, id,
 602                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 603         }
 604         wpa_hexdump(MSG_DEBUG, "EAP-EKE: Auth_P", auth, data->sess.prf_len);
 605
 606         if (eap_eke_derive_msk(&data->sess, data->serverid, data->serverid_len,
 607                                data->peerid, data->peerid_len,
 608                                data->nonce_s, data->nonce_p,
 609                                data->msk, data->emsk) < 0) {
 610                 wpa_printf(MSG_INFO, "EAP-EKE: Failed to derive MSK/EMSK");
 611                 wpabuf_free(resp);
 612                 return eap_eke_build_fail(data, ret, id,
 613                                           EAP_EKE_FAIL_PRIVATE_INTERNAL_ERROR);
 614         }
 615
 616         os_memset(data->dh_priv, 0, sizeof(data->dh_priv));
 617         eap_eke_session_clean(&data->sess);
 618
 619         eap_eke_state(data, SUCCESS);
 620         ret->methodState = METHOD_MAY_CONT;
 621         ret->decision = DECISION_COND_SUCC;
 622         ret->allowNotifications = FALSE;
 623
 624         return resp;
 625 }
 626
 627
 628 static struct wpabuf * eap_eke_process_failure(struct eap_eke_data *data,
 629                                                struct eap_method_ret *ret,
 630                                                const struct wpabuf *reqData,
 631                                                const u8 *payload,
 632                                                size_t payload_len)
 633 {
 634         wpa_printf(MSG_DEBUG, "EAP-EKE: Received EAP-EKE-Failure/Request");
 635
 636         if (payload_len < 4) {
 637                 wpa_printf(MSG_DEBUG, "EAP-EKE: Too short EAP-EKE-Failure");
 638         } else {
 639                 u32 code;
 640                 code = WPA_GET_BE32(payload);
 641                 wpa_printf(MSG_INFO, "EAP-EKE: Failure-Code 0x%x", code);
 642         }
 643
 644         return eap_eke_build_fail(data, ret, eap_get_id(reqData),
 645                                   EAP_EKE_FAIL_NO_ERROR);
 646 }
 647
 648
 649 static struct wpabuf * eap_eke_process(struct eap_sm *sm, void *priv,
 650                                        struct eap_method_ret *ret,
 651                                        const struct wpabuf *reqData)
 652 {
 653         struct eap_eke_data *data = priv;
 654         struct wpabuf *resp;
 655         const u8 *pos, *end;
 656         size_t len;
 657         u8 eke_exch;
 658
 659         pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_EKE, reqData, &len);
 660         if (pos == NULL || len < 1) {
 661                 ret->ignore = TRUE;
 662                 return NULL;
 663         }
 664
 665         end = pos + len;
 666         eke_exch = *pos++;
 667
 668         wpa_printf(MSG_DEBUG, "EAP-EKE: Received frame: exch %d", eke_exch);
 669         wpa_hexdump(MSG_DEBUG, "EAP-EKE: Received Data", pos, end - pos);
 670
 671         ret->ignore = FALSE;
 672         ret->methodState = METHOD_MAY_CONT;
 673         ret->decision = DECISION_FAIL;
 674         ret->allowNotifications = TRUE;
 675
 676         switch (eke_exch) {
 677         case EAP_EKE_ID:
 678                 resp = eap_eke_process_id(data, ret, reqData, pos, end - pos);
 679                 break;
 680         case EAP_EKE_COMMIT:
 681                 resp = eap_eke_process_commit(sm, data, ret, reqData,
 682                                               pos, end - pos);
 683                 break;
 684         case EAP_EKE_CONFIRM:
 685                 resp = eap_eke_process_confirm(data, ret, reqData,
 686                                                pos, end - pos);
 687                 break;
 688         case EAP_EKE_FAILURE:
 689                 resp = eap_eke_process_failure(data, ret, reqData,
 690                                                pos, end - pos);
 691                 break;
 692         default:
 693                 wpa_printf(MSG_DEBUG, "EAP-EKE: Ignoring message with unknown EKE-Exch %d", eke_exch);
 694                 ret->ignore = TRUE;
 695                 return NULL;
 696         }
 697
 698         if (ret->methodState == METHOD_DONE)
 699                 ret->allowNotifications = FALSE;
 700
 701         return resp;
 702 }
 703
 704
 705 static Boolean eap_eke_isKeyAvailable(struct eap_sm *sm, void *priv)
 706 {
 707         struct eap_eke_data *data = priv;
 708         return data->state == SUCCESS;
 709 }
 710
 711
 712 static u8 * eap_eke_getKey(struct eap_sm *sm, void *priv, size_t *len)
 713 {
 714         struct eap_eke_data *data = priv;
 715         u8 *key;
 716
 717         if (data->state != SUCCESS)
 718                 return NULL;
 719
 720         key = os_malloc(EAP_MSK_LEN);
 721         if (key == NULL)
 722                 return NULL;
 723         os_memcpy(key, data->msk, EAP_MSK_LEN);
 724         *len = EAP_MSK_LEN;
 725
 726         return key;
 727 }
 728
 729
 730 static u8 * eap_eke_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
 731 {
 732         struct eap_eke_data *data = priv;
 733         u8 *key;
 734
 735         if (data->state != SUCCESS)
 736                 return NULL;
 737
 738         key = os_malloc(EAP_EMSK_LEN);
 739         if (key == NULL)
 740                 return NULL;
 741         os_memcpy(key, data->emsk, EAP_EMSK_LEN);
 742         *len = EAP_EMSK_LEN;
 743
 744         return key;
 745 }
 746
 747
 748 static u8 * eap_eke_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
 749 {
 750         struct eap_eke_data *data = priv;
 751         u8 *sid;
 752         size_t sid_len;
 753
 754         if (data->state != SUCCESS)
 755                 return NULL;
 756
 757         sid_len = 1 + 2 * data->sess.nonce_len;
 758         sid = os_malloc(sid_len);
 759         if (sid == NULL)
 760                 return NULL;
 761         sid[0] = EAP_TYPE_EKE;
 762         os_memcpy(sid + 1, data->nonce_p, data->sess.nonce_len);
 763         os_memcpy(sid + 1 + data->sess.nonce_len, data->nonce_s,
 764                   data->sess.nonce_len);
 765         *len = sid_len;
 766
 767         return sid;
 768 }
 769
 770
 771 int eap_peer_eke_register(void)
 772 {
 773         struct eap_method *eap;
 774
 775         eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
 776                                     EAP_VENDOR_IETF, EAP_TYPE_EKE, "EKE");
 777         if (eap == NULL)
 778                 return -1;
 779
 780         eap->init = eap_eke_init;
 781         eap->deinit = eap_eke_deinit;
 782         eap->process = eap_eke_process;
 783         eap->isKeyAvailable = eap_eke_isKeyAvailable;
 784         eap->getKey = eap_eke_getKey;
 785         eap->get_emsk = eap_eke_get_emsk;
 786         eap->getSessionId = eap_eke_get_session_id;
 787
 788         return eap_peer_method_register(eap);
 789 }