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00015 #include "includes.h"
00016
00017 #include "common.h"
00018 #include "eap_common/eap_pax_common.h"
00019 #include "eap_i.h"
00020
00021
00022
00023
00024
00025
00026
00027
00028
00029
00030 struct eap_pax_data {
00031 enum { PAX_INIT, PAX_STD_2_SENT, PAX_DONE } state;
00032 u8 mac_id, dh_group_id, public_key_id;
00033 union {
00034 u8 e[2 * EAP_PAX_RAND_LEN];
00035 struct {
00036 u8 x[EAP_PAX_RAND_LEN];
00037 u8 y[EAP_PAX_RAND_LEN];
00038 } r;
00039 } rand;
00040 char *cid;
00041 size_t cid_len;
00042 u8 ak[EAP_PAX_AK_LEN];
00043 u8 mk[EAP_PAX_MK_LEN];
00044 u8 ck[EAP_PAX_CK_LEN];
00045 u8 ick[EAP_PAX_ICK_LEN];
00046 };
00047
00048
00049 static void eap_pax_deinit(struct eap_sm *sm, void *priv);
00050
00051
00052 static void * eap_pax_init(struct eap_sm *sm)
00053 {
00054 struct eap_pax_data *data;
00055 const u8 *identity, *password;
00056 size_t identity_len, password_len;
00057
00058 identity = eap_get_config_identity(sm, &identity_len);
00059 password = eap_get_config_password(sm, &password_len);
00060 if (!identity || !password) {
00061 wpa_printf(MSG_INFO, "EAP-PAX: CID (nai) or key (password) "
00062 "not configured");
00063 return NULL;
00064 }
00065
00066 if (password_len != EAP_PAX_AK_LEN) {
00067 wpa_printf(MSG_INFO, "EAP-PAX: Invalid PSK length");
00068 return NULL;
00069 }
00070
00071 data = os_zalloc(sizeof(*data));
00072 if (data == NULL)
00073 return NULL;
00074 data->state = PAX_INIT;
00075
00076 data->cid = os_malloc(identity_len);
00077 if (data->cid == NULL) {
00078 eap_pax_deinit(sm, data);
00079 return NULL;
00080 }
00081 os_memcpy(data->cid, identity, identity_len);
00082 data->cid_len = identity_len;
00083
00084 os_memcpy(data->ak, password, EAP_PAX_AK_LEN);
00085
00086 return data;
00087 }
00088
00089
00090 static void eap_pax_deinit(struct eap_sm *sm, void *priv)
00091 {
00092 struct eap_pax_data *data = priv;
00093 os_free(data->cid);
00094 os_free(data);
00095 }
00096
00097
00098 static struct wpabuf * eap_pax_alloc_resp(const struct eap_pax_hdr *req,
00099 u8 id, u8 op_code, size_t plen)
00100 {
00101 struct wpabuf *resp;
00102 struct eap_pax_hdr *pax;
00103
00104 resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PAX,
00105 sizeof(*pax) + plen, EAP_CODE_RESPONSE, id);
00106 if (resp == NULL)
00107 return NULL;
00108
00109 pax = wpabuf_put(resp, sizeof(*pax));
00110 pax->op_code = op_code;
00111 pax->flags = 0;
00112 pax->mac_id = req->mac_id;
00113 pax->dh_group_id = req->dh_group_id;
00114 pax->public_key_id = req->public_key_id;
00115
00116 return resp;
00117 }
00118
00119
00120 static struct wpabuf * eap_pax_process_std_1(struct eap_pax_data *data,
00121 struct eap_method_ret *ret, u8 id,
00122 const struct eap_pax_hdr *req,
00123 size_t req_plen)
00124 {
00125 struct wpabuf *resp;
00126 const u8 *pos;
00127 u8 *rpos;
00128 size_t left, plen;
00129
00130 wpa_printf(MSG_DEBUG, "EAP-PAX: PAX_STD-1 (received)");
00131
00132 if (data->state != PAX_INIT) {
00133 wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-1 received in "
00134 "unexpected state (%d) - ignored", data->state);
00135 ret->ignore = TRUE;
00136 return NULL;
00137 }
00138
00139 if (req->flags & EAP_PAX_FLAGS_CE) {
00140 wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-1 with CE flag set - "
00141 "ignored");
00142 ret->ignore = TRUE;
00143 return NULL;
00144 }
00145
00146 left = req_plen - sizeof(*req);
00147
00148 if (left < 2 + EAP_PAX_RAND_LEN) {
00149 wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-1 with too short "
00150 "payload");
00151 ret->ignore = TRUE;
00152 return NULL;
00153 }
00154
00155 pos = (const u8 *) (req + 1);
00156 if (WPA_GET_BE16(pos) != EAP_PAX_RAND_LEN) {
00157 wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-1 with incorrect A "
00158 "length %d (expected %d)",
00159 WPA_GET_BE16(pos), EAP_PAX_RAND_LEN);
00160 ret->ignore = TRUE;
00161 return NULL;
00162 }
00163
00164 pos += 2;
00165 left -= 2;
00166 os_memcpy(data->rand.r.x, pos, EAP_PAX_RAND_LEN);
00167 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: X (server rand)",
00168 data->rand.r.x, EAP_PAX_RAND_LEN);
00169 pos += EAP_PAX_RAND_LEN;
00170 left -= EAP_PAX_RAND_LEN;
00171
00172 if (left > 0) {
00173 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ignored extra payload",
00174 pos, left);
00175 }
00176
00177 if (os_get_random(data->rand.r.y, EAP_PAX_RAND_LEN)) {
00178 wpa_printf(MSG_ERROR, "EAP-PAX: Failed to get random data");
00179 ret->ignore = TRUE;
00180 return NULL;
00181 }
00182 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: Y (client rand)",
00183 data->rand.r.y, EAP_PAX_RAND_LEN);
00184
00185 if (eap_pax_initial_key_derivation(req->mac_id, data->ak, data->rand.e,
00186 data->mk, data->ck, data->ick) < 0)
00187 {
00188 ret->ignore = TRUE;
00189 return NULL;
00190 }
00191
00192 wpa_printf(MSG_DEBUG, "EAP-PAX: PAX_STD-2 (sending)");
00193
00194 plen = 2 + EAP_PAX_RAND_LEN + 2 + data->cid_len + 2 + EAP_PAX_MAC_LEN +
00195 EAP_PAX_ICV_LEN;
00196 resp = eap_pax_alloc_resp(req, id, EAP_PAX_OP_STD_2, plen);
00197 if (resp == NULL)
00198 return NULL;
00199
00200 wpabuf_put_be16(resp, EAP_PAX_RAND_LEN);
00201 wpabuf_put_data(resp, data->rand.r.y, EAP_PAX_RAND_LEN);
00202 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: B = Y (client rand)",
00203 data->rand.r.y, EAP_PAX_RAND_LEN);
00204
00205 wpabuf_put_be16(resp, data->cid_len);
00206 wpabuf_put_data(resp, data->cid, data->cid_len);
00207 wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-PAX: CID",
00208 (u8 *) data->cid, data->cid_len);
00209
00210 wpabuf_put_be16(resp, EAP_PAX_MAC_LEN);
00211 rpos = wpabuf_put(resp, EAP_PAX_MAC_LEN);
00212 eap_pax_mac(req->mac_id, data->ck, EAP_PAX_CK_LEN,
00213 data->rand.r.x, EAP_PAX_RAND_LEN,
00214 data->rand.r.y, EAP_PAX_RAND_LEN,
00215 (u8 *) data->cid, data->cid_len, rpos);
00216 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: MAC_CK(A, B, CID)",
00217 rpos, EAP_PAX_MAC_LEN);
00218
00219
00220
00221 rpos = wpabuf_put(resp, EAP_PAX_ICV_LEN);
00222 eap_pax_mac(req->mac_id, data->ick, EAP_PAX_ICK_LEN,
00223 wpabuf_head(resp), wpabuf_len(resp) - EAP_PAX_ICV_LEN,
00224 NULL, 0, NULL, 0, rpos);
00225 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", rpos, EAP_PAX_ICV_LEN);
00226
00227 data->state = PAX_STD_2_SENT;
00228 data->mac_id = req->mac_id;
00229 data->dh_group_id = req->dh_group_id;
00230 data->public_key_id = req->public_key_id;
00231
00232 return resp;
00233 }
00234
00235
00236 static struct wpabuf * eap_pax_process_std_3(struct eap_pax_data *data,
00237 struct eap_method_ret *ret, u8 id,
00238 const struct eap_pax_hdr *req,
00239 size_t req_plen)
00240 {
00241 struct wpabuf *resp;
00242 u8 *rpos, mac[EAP_PAX_MAC_LEN];
00243 const u8 *pos;
00244 size_t left;
00245
00246 wpa_printf(MSG_DEBUG, "EAP-PAX: PAX_STD-3 (received)");
00247
00248 if (data->state != PAX_STD_2_SENT) {
00249 wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-3 received in "
00250 "unexpected state (%d) - ignored", data->state);
00251 ret->ignore = TRUE;
00252 return NULL;
00253 }
00254
00255 if (req->flags & EAP_PAX_FLAGS_CE) {
00256 wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-3 with CE flag set - "
00257 "ignored");
00258 ret->ignore = TRUE;
00259 return NULL;
00260 }
00261
00262 left = req_plen - sizeof(*req);
00263
00264 if (left < 2 + EAP_PAX_MAC_LEN) {
00265 wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-3 with too short "
00266 "payload");
00267 ret->ignore = TRUE;
00268 return NULL;
00269 }
00270
00271 pos = (const u8 *) (req + 1);
00272 if (WPA_GET_BE16(pos) != EAP_PAX_MAC_LEN) {
00273 wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-3 with incorrect "
00274 "MAC_CK length %d (expected %d)",
00275 WPA_GET_BE16(pos), EAP_PAX_MAC_LEN);
00276 ret->ignore = TRUE;
00277 return NULL;
00278 }
00279 pos += 2;
00280 left -= 2;
00281 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: MAC_CK(B, CID)",
00282 pos, EAP_PAX_MAC_LEN);
00283 eap_pax_mac(data->mac_id, data->ck, EAP_PAX_CK_LEN,
00284 data->rand.r.y, EAP_PAX_RAND_LEN,
00285 (u8 *) data->cid, data->cid_len, NULL, 0, mac);
00286 if (os_memcmp(pos, mac, EAP_PAX_MAC_LEN) != 0) {
00287 wpa_printf(MSG_INFO, "EAP-PAX: Invalid MAC_CK(B, CID) "
00288 "received");
00289 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: expected MAC_CK(B, CID)",
00290 mac, EAP_PAX_MAC_LEN);
00291 ret->methodState = METHOD_DONE;
00292 ret->decision = DECISION_FAIL;
00293 return NULL;
00294 }
00295
00296 pos += EAP_PAX_MAC_LEN;
00297 left -= EAP_PAX_MAC_LEN;
00298
00299 if (left > 0) {
00300 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ignored extra payload",
00301 pos, left);
00302 }
00303
00304 wpa_printf(MSG_DEBUG, "EAP-PAX: PAX-ACK (sending)");
00305
00306 resp = eap_pax_alloc_resp(req, id, EAP_PAX_OP_ACK, EAP_PAX_ICV_LEN);
00307 if (resp == NULL)
00308 return NULL;
00309
00310
00311
00312 rpos = wpabuf_put(resp, EAP_PAX_ICV_LEN);
00313 eap_pax_mac(data->mac_id, data->ick, EAP_PAX_ICK_LEN,
00314 wpabuf_head(resp), wpabuf_len(resp) - EAP_PAX_ICV_LEN,
00315 NULL, 0, NULL, 0, rpos);
00316 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", rpos, EAP_PAX_ICV_LEN);
00317
00318 data->state = PAX_DONE;
00319 ret->methodState = METHOD_DONE;
00320 ret->decision = DECISION_UNCOND_SUCC;
00321 ret->allowNotifications = FALSE;
00322
00323 return resp;
00324 }
00325
00326
00327 static struct wpabuf * eap_pax_process(struct eap_sm *sm, void *priv,
00328 struct eap_method_ret *ret,
00329 const struct wpabuf *reqData)
00330 {
00331 struct eap_pax_data *data = priv;
00332 const struct eap_pax_hdr *req;
00333 struct wpabuf *resp;
00334 u8 icvbuf[EAP_PAX_ICV_LEN], id;
00335 const u8 *icv, *pos;
00336 size_t len;
00337 u16 flen, mlen;
00338
00339 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PAX, reqData, &len);
00340 if (pos == NULL || len < EAP_PAX_ICV_LEN) {
00341 ret->ignore = TRUE;
00342 return NULL;
00343 }
00344 id = eap_get_id(reqData);
00345 req = (const struct eap_pax_hdr *) pos;
00346 flen = len - EAP_PAX_ICV_LEN;
00347 mlen = wpabuf_len(reqData) - EAP_PAX_ICV_LEN;
00348
00349 wpa_printf(MSG_DEBUG, "EAP-PAX: received frame: op_code 0x%x "
00350 "flags 0x%x mac_id 0x%x dh_group_id 0x%x "
00351 "public_key_id 0x%x",
00352 req->op_code, req->flags, req->mac_id, req->dh_group_id,
00353 req->public_key_id);
00354 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: received payload",
00355 pos, len - EAP_PAX_ICV_LEN);
00356
00357 if (data->state != PAX_INIT && data->mac_id != req->mac_id) {
00358 wpa_printf(MSG_INFO, "EAP-PAX: MAC ID changed during "
00359 "authentication (was 0x%d, is 0x%d)",
00360 data->mac_id, req->mac_id);
00361 ret->ignore = TRUE;
00362 return NULL;
00363 }
00364
00365 if (data->state != PAX_INIT && data->dh_group_id != req->dh_group_id) {
00366 wpa_printf(MSG_INFO, "EAP-PAX: DH Group ID changed during "
00367 "authentication (was 0x%d, is 0x%d)",
00368 data->dh_group_id, req->dh_group_id);
00369 ret->ignore = TRUE;
00370 return NULL;
00371 }
00372
00373 if (data->state != PAX_INIT &&
00374 data->public_key_id != req->public_key_id) {
00375 wpa_printf(MSG_INFO, "EAP-PAX: Public Key ID changed during "
00376 "authentication (was 0x%d, is 0x%d)",
00377 data->public_key_id, req->public_key_id);
00378 ret->ignore = TRUE;
00379 return NULL;
00380 }
00381
00382
00383 if (req->mac_id != EAP_PAX_MAC_HMAC_SHA1_128) {
00384 wpa_printf(MSG_INFO, "EAP-PAX: Unsupported MAC ID 0x%x",
00385 req->mac_id);
00386 ret->ignore = TRUE;
00387 return NULL;
00388 }
00389
00390 if (req->dh_group_id != EAP_PAX_DH_GROUP_NONE) {
00391 wpa_printf(MSG_INFO, "EAP-PAX: Unsupported DH Group ID 0x%x",
00392 req->dh_group_id);
00393 ret->ignore = TRUE;
00394 return NULL;
00395 }
00396
00397 if (req->public_key_id != EAP_PAX_PUBLIC_KEY_NONE) {
00398 wpa_printf(MSG_INFO, "EAP-PAX: Unsupported Public Key ID 0x%x",
00399 req->public_key_id);
00400 ret->ignore = TRUE;
00401 return NULL;
00402 }
00403
00404 if (req->flags & EAP_PAX_FLAGS_MF) {
00405
00406 wpa_printf(MSG_INFO, "EAP-PAX: fragmentation not supported - "
00407 "ignored packet");
00408 ret->ignore = TRUE;
00409 return NULL;
00410 }
00411
00412 icv = pos + len - EAP_PAX_ICV_LEN;
00413 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", icv, EAP_PAX_ICV_LEN);
00414 if (req->op_code == EAP_PAX_OP_STD_1) {
00415 eap_pax_mac(req->mac_id, (u8 *) "", 0,
00416 wpabuf_head(reqData), mlen, NULL, 0, NULL, 0,
00417 icvbuf);
00418 } else {
00419 eap_pax_mac(req->mac_id, data->ick, EAP_PAX_ICK_LEN,
00420 wpabuf_head(reqData), mlen, NULL, 0, NULL, 0,
00421 icvbuf);
00422 }
00423 if (os_memcmp(icv, icvbuf, EAP_PAX_ICV_LEN) != 0) {
00424 wpa_printf(MSG_DEBUG, "EAP-PAX: invalid ICV - ignoring the "
00425 "message");
00426 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: expected ICV",
00427 icvbuf, EAP_PAX_ICV_LEN);
00428 ret->ignore = TRUE;
00429 return NULL;
00430 }
00431
00432 ret->ignore = FALSE;
00433 ret->methodState = METHOD_MAY_CONT;
00434 ret->decision = DECISION_FAIL;
00435 ret->allowNotifications = TRUE;
00436
00437 switch (req->op_code) {
00438 case EAP_PAX_OP_STD_1:
00439 resp = eap_pax_process_std_1(data, ret, id, req, flen);
00440 break;
00441 case EAP_PAX_OP_STD_3:
00442 resp = eap_pax_process_std_3(data, ret, id, req, flen);
00443 break;
00444 default:
00445 wpa_printf(MSG_DEBUG, "EAP-PAX: ignoring message with unknown "
00446 "op_code %d", req->op_code);
00447 ret->ignore = TRUE;
00448 return NULL;
00449 }
00450
00451 if (ret->methodState == METHOD_DONE) {
00452 ret->allowNotifications = FALSE;
00453 }
00454
00455 return resp;
00456 }
00457
00458
00459 static Boolean eap_pax_isKeyAvailable(struct eap_sm *sm, void *priv)
00460 {
00461 struct eap_pax_data *data = priv;
00462 return data->state == PAX_DONE;
00463 }
00464
00465
00466 static u8 * eap_pax_getKey(struct eap_sm *sm, void *priv, size_t *len)
00467 {
00468 struct eap_pax_data *data = priv;
00469 u8 *key;
00470
00471 if (data->state != PAX_DONE)
00472 return NULL;
00473
00474 key = os_malloc(EAP_MSK_LEN);
00475 if (key == NULL)
00476 return NULL;
00477
00478 *len = EAP_MSK_LEN;
00479 eap_pax_kdf(data->mac_id, data->mk, EAP_PAX_MK_LEN,
00480 "Master Session Key", data->rand.e, 2 * EAP_PAX_RAND_LEN,
00481 EAP_MSK_LEN, key);
00482
00483 return key;
00484 }
00485
00486
00487 static u8 * eap_pax_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
00488 {
00489 struct eap_pax_data *data = priv;
00490 u8 *key;
00491
00492 if (data->state != PAX_DONE)
00493 return NULL;
00494
00495 key = os_malloc(EAP_EMSK_LEN);
00496 if (key == NULL)
00497 return NULL;
00498
00499 *len = EAP_EMSK_LEN;
00500 eap_pax_kdf(data->mac_id, data->mk, EAP_PAX_MK_LEN,
00501 "Extended Master Session Key",
00502 data->rand.e, 2 * EAP_PAX_RAND_LEN,
00503 EAP_EMSK_LEN, key);
00504
00505 return key;
00506 }
00507
00508
00509 int eap_peer_pax_register(void)
00510 {
00511 struct eap_method *eap;
00512 int ret;
00513
00514 eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
00515 EAP_VENDOR_IETF, EAP_TYPE_PAX, "PAX");
00516 if (eap == NULL)
00517 return -1;
00518
00519 eap->init = eap_pax_init;
00520 eap->deinit = eap_pax_deinit;
00521 eap->process = eap_pax_process;
00522 eap->isKeyAvailable = eap_pax_isKeyAvailable;
00523 eap->getKey = eap_pax_getKey;
00524 eap->get_emsk = eap_pax_get_emsk;
00525
00526 ret = eap_peer_method_register(eap);
00527 if (ret)
00528 eap_peer_method_free(eap);
00529 return ret;
00530 }
