contrib/wpa/src/eap_server/eap_server_pax.c

   1 /*
   2  * hostapd / EAP-PAX (RFC 4746) server
   3  * Copyright (c) 2005-2007, 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_server/eap_i.h"
  14 #include "eap_common/eap_pax_common.h"
  15
  16 /*
  17  * Note: only PAX_STD subprotocol is currently supported
  18  *
  19  * TODO: Add support with PAX_SEC with the mandatory to implement ciphersuite
  20  * (HMAC_SHA1_128, IANA DH Group 14 (2048 bits), RSA-PKCS1-V1_5) and
  21  * recommended ciphersuite (HMAC_SHA256_128, IANA DH Group 15 (3072 bits),
  22  * RSAES-OAEP).
  23  */
  24
  25 struct eap_pax_data {
  26         enum { PAX_STD_1, PAX_STD_3, SUCCESS, FAILURE } state;
  27         u8 mac_id;
  28         union {
  29                 u8 e[2 * EAP_PAX_RAND_LEN];
  30                 struct {
  31                         u8 x[EAP_PAX_RAND_LEN]; /* server rand */
  32                         u8 y[EAP_PAX_RAND_LEN]; /* client rand */
  33                 } r;
  34         } rand;
  35         u8 ak[EAP_PAX_AK_LEN];
  36         u8 mk[EAP_PAX_MK_LEN];
  37         u8 ck[EAP_PAX_CK_LEN];
  38         u8 ick[EAP_PAX_ICK_LEN];
  39         u8 mid[EAP_PAX_MID_LEN];
  40         int keys_set;
  41         char *cid;
  42         size_t cid_len;
  43 };
  44
  45
  46 static void * eap_pax_init(struct eap_sm *sm)
  47 {
  48         struct eap_pax_data *data;
  49
  50         data = os_zalloc(sizeof(*data));
  51         if (data == NULL)
  52                 return NULL;
  53         data->state = PAX_STD_1;
  54         /*
  55          * TODO: make this configurable once EAP_PAX_HMAC_SHA256_128 is
  56          * supported
  57          */
  58         data->mac_id = EAP_PAX_MAC_HMAC_SHA1_128;
  59
  60         return data;
  61 }
  62
  63
  64 static void eap_pax_reset(struct eap_sm *sm, void *priv)
  65 {
  66         struct eap_pax_data *data = priv;
  67         os_free(data->cid);
  68         bin_clear_free(data, sizeof(*data));
  69 }
  70
  71
  72 static struct wpabuf * eap_pax_build_std_1(struct eap_sm *sm,
  73                                            struct eap_pax_data *data, u8 id)
  74 {
  75         struct wpabuf *req;
  76         struct eap_pax_hdr *pax;
  77         u8 *pos;
  78
  79         wpa_printf(MSG_DEBUG, "EAP-PAX: PAX_STD-1 (sending)");
  80
  81         if (random_get_bytes(data->rand.r.x, EAP_PAX_RAND_LEN)) {
  82                 wpa_printf(MSG_ERROR, "EAP-PAX: Failed to get random data");
  83                 data->state = FAILURE;
  84                 return NULL;
  85         }
  86
  87         req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PAX,
  88                             sizeof(*pax) + 2 + EAP_PAX_RAND_LEN +
  89                             EAP_PAX_ICV_LEN, EAP_CODE_REQUEST, id);
  90         if (req == NULL) {
  91                 wpa_printf(MSG_ERROR, "EAP-PAX: Failed to allocate memory "
  92                            "request");
  93                 data->state = FAILURE;
  94                 return NULL;
  95         }
  96
  97         pax = wpabuf_put(req, sizeof(*pax));
  98         pax->op_code = EAP_PAX_OP_STD_1;
  99         pax->flags = 0;
 100         pax->mac_id = data->mac_id;
 101         pax->dh_group_id = EAP_PAX_DH_GROUP_NONE;
 102         pax->public_key_id = EAP_PAX_PUBLIC_KEY_NONE;
 103
 104         wpabuf_put_be16(req, EAP_PAX_RAND_LEN);
 105         wpabuf_put_data(req, data->rand.r.x, EAP_PAX_RAND_LEN);
 106         wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: A = X (server rand)",
 107                     data->rand.r.x, EAP_PAX_RAND_LEN);
 108
 109         pos = wpabuf_put(req, EAP_PAX_MAC_LEN);
 110         eap_pax_mac(data->mac_id, (u8 *) "", 0,
 111                     wpabuf_mhead(req), wpabuf_len(req) - EAP_PAX_ICV_LEN,
 112                     NULL, 0, NULL, 0, pos);
 113         wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", pos, EAP_PAX_ICV_LEN);
 114
 115         return req;
 116 }
 117
 118
 119 static struct wpabuf * eap_pax_build_std_3(struct eap_sm *sm,
 120                                            struct eap_pax_data *data, u8 id)
 121 {
 122         struct wpabuf *req;
 123         struct eap_pax_hdr *pax;
 124         u8 *pos;
 125
 126         wpa_printf(MSG_DEBUG, "EAP-PAX: PAX_STD-3 (sending)");
 127
 128         req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PAX,
 129                             sizeof(*pax) + 2 + EAP_PAX_MAC_LEN +
 130                             EAP_PAX_ICV_LEN, EAP_CODE_REQUEST, id);
 131         if (req == NULL) {
 132                 wpa_printf(MSG_ERROR, "EAP-PAX: Failed to allocate memory "
 133                            "request");
 134                 data->state = FAILURE;
 135                 return NULL;
 136         }
 137
 138         pax = wpabuf_put(req, sizeof(*pax));
 139         pax->op_code = EAP_PAX_OP_STD_3;
 140         pax->flags = 0;
 141         pax->mac_id = data->mac_id;
 142         pax->dh_group_id = EAP_PAX_DH_GROUP_NONE;
 143         pax->public_key_id = EAP_PAX_PUBLIC_KEY_NONE;
 144
 145         wpabuf_put_be16(req, EAP_PAX_MAC_LEN);
 146         pos = wpabuf_put(req, EAP_PAX_MAC_LEN);
 147         eap_pax_mac(data->mac_id, data->ck, EAP_PAX_CK_LEN,
 148                     data->rand.r.y, EAP_PAX_RAND_LEN,
 149                     (u8 *) data->cid, data->cid_len, NULL, 0, pos);
 150         wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: MAC_CK(B, CID)",
 151                     pos, EAP_PAX_MAC_LEN);
 152
 153         /* Optional ADE could be added here, if needed */
 154
 155         pos = wpabuf_put(req, EAP_PAX_MAC_LEN);
 156         eap_pax_mac(data->mac_id, data->ick, EAP_PAX_ICK_LEN,
 157                     wpabuf_mhead(req), wpabuf_len(req) - EAP_PAX_ICV_LEN,
 158                     NULL, 0, NULL, 0, pos);
 159         wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", pos, EAP_PAX_ICV_LEN);
 160
 161         return req;
 162 }
 163
 164
 165 static struct wpabuf * eap_pax_buildReq(struct eap_sm *sm, void *priv, u8 id)
 166 {
 167         struct eap_pax_data *data = priv;
 168
 169         switch (data->state) {
 170         case PAX_STD_1:
 171                 return eap_pax_build_std_1(sm, data, id);
 172         case PAX_STD_3:
 173                 return eap_pax_build_std_3(sm, data, id);
 174         default:
 175                 wpa_printf(MSG_DEBUG, "EAP-PAX: Unknown state %d in buildReq",
 176                            data->state);
 177                 break;
 178         }
 179         return NULL;
 180 }
 181
 182
 183 static Boolean eap_pax_check(struct eap_sm *sm, void *priv,
 184                              struct wpabuf *respData)
 185 {
 186         struct eap_pax_data *data = priv;
 187         struct eap_pax_hdr *resp;
 188         const u8 *pos;
 189         size_t len, mlen;
 190         u8 icvbuf[EAP_PAX_ICV_LEN], *icv;
 191
 192         pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PAX, respData, &len);
 193         if (pos == NULL || len < sizeof(*resp)) {
 194                 wpa_printf(MSG_INFO, "EAP-PAX: Invalid frame");
 195                 return TRUE;
 196         }
 197
 198         mlen = sizeof(struct eap_hdr) + 1 + len;
 199         resp = (struct eap_pax_hdr *) pos;
 200
 201         wpa_printf(MSG_DEBUG, "EAP-PAX: received frame: op_code 0x%x "
 202                    "flags 0x%x mac_id 0x%x dh_group_id 0x%x "
 203                    "public_key_id 0x%x",
 204                    resp->op_code, resp->flags, resp->mac_id, resp->dh_group_id,
 205                    resp->public_key_id);
 206         wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: received payload",
 207                     (u8 *) (resp + 1), len - sizeof(*resp) - EAP_PAX_ICV_LEN);
 208
 209         if (data->state == PAX_STD_1 &&
 210             resp->op_code != EAP_PAX_OP_STD_2) {
 211                 wpa_printf(MSG_DEBUG, "EAP-PAX: Expected PAX_STD-2 - "
 212                            "ignore op %d", resp->op_code);
 213                 return TRUE;
 214         }
 215
 216         if (data->state == PAX_STD_3 &&
 217             resp->op_code != EAP_PAX_OP_ACK) {
 218                 wpa_printf(MSG_DEBUG, "EAP-PAX: Expected PAX-ACK - "
 219                            "ignore op %d", resp->op_code);
 220                 return TRUE;
 221         }
 222
 223         if (resp->op_code != EAP_PAX_OP_STD_2 &&
 224             resp->op_code != EAP_PAX_OP_ACK) {
 225                 wpa_printf(MSG_DEBUG, "EAP-PAX: Unknown op_code 0x%x",
 226                            resp->op_code);
 227         }
 228
 229         if (data->mac_id != resp->mac_id) {
 230                 wpa_printf(MSG_DEBUG, "EAP-PAX: Expected MAC ID 0x%x, "
 231                            "received 0x%x", data->mac_id, resp->mac_id);
 232                 return TRUE;
 233         }
 234
 235         if (resp->dh_group_id != EAP_PAX_DH_GROUP_NONE) {
 236                 wpa_printf(MSG_INFO, "EAP-PAX: Expected DH Group ID 0x%x, "
 237                            "received 0x%x", EAP_PAX_DH_GROUP_NONE,
 238                            resp->dh_group_id);
 239                 return TRUE;
 240         }
 241
 242         if (resp->public_key_id != EAP_PAX_PUBLIC_KEY_NONE) {
 243                 wpa_printf(MSG_INFO, "EAP-PAX: Expected Public Key ID 0x%x, "
 244                            "received 0x%x", EAP_PAX_PUBLIC_KEY_NONE,
 245                            resp->public_key_id);
 246                 return TRUE;
 247         }
 248
 249         if (resp->flags & EAP_PAX_FLAGS_MF) {
 250                 /* TODO: add support for reassembling fragments */
 251                 wpa_printf(MSG_INFO, "EAP-PAX: fragmentation not supported");
 252                 return TRUE;
 253         }
 254
 255         if (resp->flags & EAP_PAX_FLAGS_CE) {
 256                 wpa_printf(MSG_INFO, "EAP-PAX: Unexpected CE flag");
 257                 return TRUE;
 258         }
 259
 260         if (data->keys_set) {
 261                 if (len - sizeof(*resp) < EAP_PAX_ICV_LEN) {
 262                         wpa_printf(MSG_INFO, "EAP-PAX: No ICV in the packet");
 263                         return TRUE;
 264                 }
 265                 icv = wpabuf_mhead_u8(respData) + mlen - EAP_PAX_ICV_LEN;
 266                 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", icv, EAP_PAX_ICV_LEN);
 267                 eap_pax_mac(data->mac_id, data->ick, EAP_PAX_ICK_LEN,
 268                             wpabuf_mhead(respData),
 269                             wpabuf_len(respData) - EAP_PAX_ICV_LEN,
 270                             NULL, 0, NULL, 0, icvbuf);
 271                 if (os_memcmp_const(icvbuf, icv, EAP_PAX_ICV_LEN) != 0) {
 272                         wpa_printf(MSG_INFO, "EAP-PAX: Invalid ICV");
 273                         wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: Expected ICV",
 274                                     icvbuf, EAP_PAX_ICV_LEN);
 275                         return TRUE;
 276                 }
 277         }
 278
 279         return FALSE;
 280 }
 281
 282
 283 static void eap_pax_process_std_2(struct eap_sm *sm,
 284                                   struct eap_pax_data *data,
 285                                   struct wpabuf *respData)
 286 {
 287         struct eap_pax_hdr *resp;
 288         u8 mac[EAP_PAX_MAC_LEN], icvbuf[EAP_PAX_ICV_LEN];
 289         const u8 *pos;
 290         size_t len, left, cid_len;
 291         int i;
 292
 293         if (data->state != PAX_STD_1)
 294                 return;
 295
 296         wpa_printf(MSG_DEBUG, "EAP-PAX: Received PAX_STD-2");
 297
 298         pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PAX, respData, &len);
 299         if (pos == NULL || len < sizeof(*resp) + EAP_PAX_ICV_LEN)
 300                 return;
 301
 302         resp = (struct eap_pax_hdr *) pos;
 303         pos = (u8 *) (resp + 1);
 304         left = len - sizeof(*resp);
 305
 306         if (left < 2 + EAP_PAX_RAND_LEN ||
 307             WPA_GET_BE16(pos) != EAP_PAX_RAND_LEN) {
 308                 wpa_printf(MSG_INFO, "EAP-PAX: Too short PAX_STD-2 (B)");
 309                 return;
 310         }
 311         pos += 2;
 312         left -= 2;
 313         os_memcpy(data->rand.r.y, pos, EAP_PAX_RAND_LEN);
 314         wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: Y (client rand)",
 315                     data->rand.r.y, EAP_PAX_RAND_LEN);
 316         pos += EAP_PAX_RAND_LEN;
 317         left -= EAP_PAX_RAND_LEN;
 318
 319         if (left < 2 || (size_t) 2 + WPA_GET_BE16(pos) > left) {
 320                 wpa_printf(MSG_INFO, "EAP-PAX: Too short PAX_STD-2 (CID)");
 321                 return;
 322         }
 323         cid_len = WPA_GET_BE16(pos);
 324         if (cid_len > 1500) {
 325                 wpa_printf(MSG_INFO, "EAP-PAX: Too long CID");
 326                 return;
 327         }
 328         data->cid_len = cid_len;
 329         os_free(data->cid);
 330         data->cid = os_memdup(pos + 2, data->cid_len);
 331         if (data->cid == NULL) {
 332                 wpa_printf(MSG_INFO, "EAP-PAX: Failed to allocate memory for "
 333                            "CID");
 334                 return;
 335         }
 336         pos += 2 + data->cid_len;
 337         left -= 2 + data->cid_len;
 338         wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-PAX: CID",
 339                           (u8 *) data->cid, data->cid_len);
 340
 341         if (left < 2 + EAP_PAX_MAC_LEN ||
 342             WPA_GET_BE16(pos) != EAP_PAX_MAC_LEN) {
 343                 wpa_printf(MSG_INFO, "EAP-PAX: Too short PAX_STD-2 (MAC_CK)");
 344                 return;
 345         }
 346         pos += 2;
 347         left -= 2;
 348         wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: MAC_CK(A, B, CID)",
 349                     pos, EAP_PAX_MAC_LEN);
 350
 351         if (eap_user_get(sm, (u8 *) data->cid, data->cid_len, 0) < 0) {
 352                 wpa_hexdump_ascii(MSG_DEBUG, "EAP-PAX: unknown CID",
 353                                   (u8 *) data->cid, data->cid_len);
 354                 data->state = FAILURE;
 355                 return;
 356         }
 357
 358         for (i = 0;
 359              i < EAP_MAX_METHODS &&
 360                      (sm->user->methods[i].vendor != EAP_VENDOR_IETF ||
 361                       sm->user->methods[i].method != EAP_TYPE_NONE);
 362              i++) {
 363                 if (sm->user->methods[i].vendor == EAP_VENDOR_IETF &&
 364                     sm->user->methods[i].method == EAP_TYPE_PAX)
 365                         break;
 366         }
 367
 368         if (i >= EAP_MAX_METHODS ||
 369             sm->user->methods[i].vendor != EAP_VENDOR_IETF ||
 370             sm->user->methods[i].method != EAP_TYPE_PAX) {
 371                 wpa_hexdump_ascii(MSG_DEBUG,
 372                                   "EAP-PAX: EAP-PAX not enabled for CID",
 373                                   (u8 *) data->cid, data->cid_len);
 374                 data->state = FAILURE;
 375                 return;
 376         }
 377
 378         if (sm->user->password == NULL ||
 379             sm->user->password_len != EAP_PAX_AK_LEN) {
 380                 wpa_hexdump_ascii(MSG_DEBUG, "EAP-PAX: invalid password in "
 381                                   "user database for CID",
 382                                   (u8 *) data->cid, data->cid_len);
 383                 data->state = FAILURE;
 384                 return;
 385         }
 386         os_memcpy(data->ak, sm->user->password, EAP_PAX_AK_LEN);
 387
 388         if (eap_pax_initial_key_derivation(data->mac_id, data->ak,
 389                                            data->rand.e, data->mk, data->ck,
 390                                            data->ick, data->mid) < 0) {
 391                 wpa_printf(MSG_INFO, "EAP-PAX: Failed to complete initial "
 392                            "key derivation");
 393                 data->state = FAILURE;
 394                 return;
 395         }
 396         data->keys_set = 1;
 397
 398         eap_pax_mac(data->mac_id, data->ck, EAP_PAX_CK_LEN,
 399                     data->rand.r.x, EAP_PAX_RAND_LEN,
 400                     data->rand.r.y, EAP_PAX_RAND_LEN,
 401                     (u8 *) data->cid, data->cid_len, mac);
 402         if (os_memcmp_const(mac, pos, EAP_PAX_MAC_LEN) != 0) {
 403                 wpa_printf(MSG_INFO, "EAP-PAX: Invalid MAC_CK(A, B, CID) in "
 404                            "PAX_STD-2");
 405                 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: Expected MAC_CK(A, B, CID)",
 406                             mac, EAP_PAX_MAC_LEN);
 407                 data->state = FAILURE;
 408                 return;
 409         }
 410
 411         pos += EAP_PAX_MAC_LEN;
 412         left -= EAP_PAX_MAC_LEN;
 413
 414         if (left < EAP_PAX_ICV_LEN) {
 415                 wpa_printf(MSG_INFO, "EAP-PAX: Too short ICV (%lu) in "
 416                            "PAX_STD-2", (unsigned long) left);
 417                 return;
 418         }
 419         wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", pos, EAP_PAX_ICV_LEN);
 420         eap_pax_mac(data->mac_id, data->ick, EAP_PAX_ICK_LEN,
 421                     wpabuf_head(respData),
 422                     wpabuf_len(respData) - EAP_PAX_ICV_LEN, NULL, 0, NULL, 0,
 423                     icvbuf);
 424         if (os_memcmp_const(icvbuf, pos, EAP_PAX_ICV_LEN) != 0) {
 425                 wpa_printf(MSG_INFO, "EAP-PAX: Invalid ICV in PAX_STD-2");
 426                 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: Expected ICV",
 427                             icvbuf, EAP_PAX_ICV_LEN);
 428                 return;
 429         }
 430         pos += EAP_PAX_ICV_LEN;
 431         left -= EAP_PAX_ICV_LEN;
 432
 433         if (left > 0) {
 434                 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ignored extra payload",
 435                             pos, left);
 436         }
 437
 438         data->state = PAX_STD_3;
 439 }
 440
 441
 442 static void eap_pax_process_ack(struct eap_sm *sm,
 443                                 struct eap_pax_data *data,
 444                                 struct wpabuf *respData)
 445 {
 446         if (data->state != PAX_STD_3)
 447                 return;
 448
 449         wpa_printf(MSG_DEBUG, "EAP-PAX: Received PAX-ACK - authentication "
 450                    "completed successfully");
 451         data->state = SUCCESS;
 452 }
 453
 454
 455 static void eap_pax_process(struct eap_sm *sm, void *priv,
 456                             struct wpabuf *respData)
 457 {
 458         struct eap_pax_data *data = priv;
 459         struct eap_pax_hdr *resp;
 460         const u8 *pos;
 461         size_t len;
 462
 463         if (sm->user == NULL || sm->user->password == NULL) {
 464                 wpa_printf(MSG_INFO, "EAP-PAX: Plaintext password not "
 465                            "configured");
 466                 data->state = FAILURE;
 467                 return;
 468         }
 469
 470         pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PAX, respData, &len);
 471         if (pos == NULL || len < sizeof(*resp))
 472                 return;
 473
 474         resp = (struct eap_pax_hdr *) pos;
 475
 476         switch (resp->op_code) {
 477         case EAP_PAX_OP_STD_2:
 478                 eap_pax_process_std_2(sm, data, respData);
 479                 break;
 480         case EAP_PAX_OP_ACK:
 481                 eap_pax_process_ack(sm, data, respData);
 482                 break;
 483         }
 484 }
 485
 486
 487 static Boolean eap_pax_isDone(struct eap_sm *sm, void *priv)
 488 {
 489         struct eap_pax_data *data = priv;
 490         return data->state == SUCCESS || data->state == FAILURE;
 491 }
 492
 493
 494 static u8 * eap_pax_getKey(struct eap_sm *sm, void *priv, size_t *len)
 495 {
 496         struct eap_pax_data *data = priv;
 497         u8 *key;
 498
 499         if (data->state != SUCCESS)
 500                 return NULL;
 501
 502         key = os_malloc(EAP_MSK_LEN);
 503         if (key == NULL)
 504                 return NULL;
 505
 506         *len = EAP_MSK_LEN;
 507         eap_pax_kdf(data->mac_id, data->mk, EAP_PAX_MK_LEN,
 508                     "Master Session Key", data->rand.e, 2 * EAP_PAX_RAND_LEN,
 509                     EAP_MSK_LEN, key);
 510
 511         return key;
 512 }
 513
 514
 515 static u8 * eap_pax_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
 516 {
 517         struct eap_pax_data *data = priv;
 518         u8 *key;
 519
 520         if (data->state != SUCCESS)
 521                 return NULL;
 522
 523         key = os_malloc(EAP_EMSK_LEN);
 524         if (key == NULL)
 525                 return NULL;
 526
 527         *len = EAP_EMSK_LEN;
 528         eap_pax_kdf(data->mac_id, data->mk, EAP_PAX_MK_LEN,
 529                     "Extended Master Session Key",
 530                     data->rand.e, 2 * EAP_PAX_RAND_LEN,
 531                     EAP_EMSK_LEN, key);
 532
 533         return key;
 534 }
 535
 536
 537 static Boolean eap_pax_isSuccess(struct eap_sm *sm, void *priv)
 538 {
 539         struct eap_pax_data *data = priv;
 540         return data->state == SUCCESS;
 541 }
 542
 543
 544 static u8 * eap_pax_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
 545 {
 546         struct eap_pax_data *data = priv;
 547         u8 *sid;
 548
 549         if (data->state != SUCCESS)
 550                 return NULL;
 551
 552         sid = os_malloc(1 + EAP_PAX_MID_LEN);
 553         if (sid == NULL)
 554                 return NULL;
 555
 556         *len = 1 + EAP_PAX_MID_LEN;
 557         sid[0] = EAP_TYPE_PAX;
 558         os_memcpy(sid + 1, data->mid, EAP_PAX_MID_LEN);
 559
 560         return sid;
 561 }
 562
 563
 564 int eap_server_pax_register(void)
 565 {
 566         struct eap_method *eap;
 567
 568         eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
 569                                       EAP_VENDOR_IETF, EAP_TYPE_PAX, "PAX");
 570         if (eap == NULL)
 571                 return -1;
 572
 573         eap->init = eap_pax_init;
 574         eap->reset = eap_pax_reset;
 575         eap->buildReq = eap_pax_buildReq;
 576         eap->check = eap_pax_check;
 577         eap->process = eap_pax_process;
 578         eap->isDone = eap_pax_isDone;
 579         eap->getKey = eap_pax_getKey;
 580         eap->isSuccess = eap_pax_isSuccess;
 581         eap->get_emsk = eap_pax_get_emsk;
 582         eap->getSessionId = eap_pax_get_session_id;
 583
 584         return eap_server_method_register(eap);
 585 }