2 * EAP peer method: EAP-PAX (RFC 4746)
3 * Copyright (c) 2005-2008, Jouni Malinen <j@w1.fi>
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
12 #include "crypto/random.h"
13 #include "eap_common/eap_pax_common.h"
17 * Note: only PAX_STD subprotocol is currently supported
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),
26 enum { PAX_INIT, PAX_STD_2_SENT, PAX_DONE } state;
27 u8 mac_id, dh_group_id, public_key_id;
29 u8 e[2 * EAP_PAX_RAND_LEN];
31 u8 x[EAP_PAX_RAND_LEN]; /* server rand */
32 u8 y[EAP_PAX_RAND_LEN]; /* client rand */
37 u8 ak[EAP_PAX_AK_LEN];
38 u8 mk[EAP_PAX_MK_LEN];
39 u8 ck[EAP_PAX_CK_LEN];
40 u8 ick[EAP_PAX_ICK_LEN];
44 static void eap_pax_deinit(struct eap_sm *sm, void *priv);
47 static void * eap_pax_init(struct eap_sm *sm)
49 struct eap_pax_data *data;
50 const u8 *identity, *password;
51 size_t identity_len, password_len;
53 identity = eap_get_config_identity(sm, &identity_len);
54 password = eap_get_config_password(sm, &password_len);
55 if (!identity || !password) {
56 wpa_printf(MSG_INFO, "EAP-PAX: CID (nai) or key (password) "
61 if (password_len != EAP_PAX_AK_LEN) {
62 wpa_printf(MSG_INFO, "EAP-PAX: Invalid PSK length");
66 data = os_zalloc(sizeof(*data));
69 data->state = PAX_INIT;
71 data->cid = os_malloc(identity_len);
72 if (data->cid == NULL) {
73 eap_pax_deinit(sm, data);
76 os_memcpy(data->cid, identity, identity_len);
77 data->cid_len = identity_len;
79 os_memcpy(data->ak, password, EAP_PAX_AK_LEN);
85 static void eap_pax_deinit(struct eap_sm *sm, void *priv)
87 struct eap_pax_data *data = priv;
93 static struct wpabuf * eap_pax_alloc_resp(const struct eap_pax_hdr *req,
94 u8 id, u8 op_code, size_t plen)
97 struct eap_pax_hdr *pax;
99 resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PAX,
100 sizeof(*pax) + plen, EAP_CODE_RESPONSE, id);
104 pax = wpabuf_put(resp, sizeof(*pax));
105 pax->op_code = op_code;
107 pax->mac_id = req->mac_id;
108 pax->dh_group_id = req->dh_group_id;
109 pax->public_key_id = req->public_key_id;
115 static struct wpabuf * eap_pax_process_std_1(struct eap_pax_data *data,
116 struct eap_method_ret *ret, u8 id,
117 const struct eap_pax_hdr *req,
125 wpa_printf(MSG_DEBUG, "EAP-PAX: PAX_STD-1 (received)");
127 if (data->state != PAX_INIT) {
128 wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-1 received in "
129 "unexpected state (%d) - ignored", data->state);
134 if (req->flags & EAP_PAX_FLAGS_CE) {
135 wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-1 with CE flag set - "
141 left = req_plen - sizeof(*req);
143 if (left < 2 + EAP_PAX_RAND_LEN) {
144 wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-1 with too short "
150 pos = (const u8 *) (req + 1);
151 if (WPA_GET_BE16(pos) != EAP_PAX_RAND_LEN) {
152 wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-1 with incorrect A "
153 "length %d (expected %d)",
154 WPA_GET_BE16(pos), EAP_PAX_RAND_LEN);
161 os_memcpy(data->rand.r.x, pos, EAP_PAX_RAND_LEN);
162 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: X (server rand)",
163 data->rand.r.x, EAP_PAX_RAND_LEN);
164 pos += EAP_PAX_RAND_LEN;
165 left -= EAP_PAX_RAND_LEN;
168 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ignored extra payload",
172 if (random_get_bytes(data->rand.r.y, EAP_PAX_RAND_LEN)) {
173 wpa_printf(MSG_ERROR, "EAP-PAX: Failed to get random data");
177 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: Y (client rand)",
178 data->rand.r.y, EAP_PAX_RAND_LEN);
180 if (eap_pax_initial_key_derivation(req->mac_id, data->ak, data->rand.e,
181 data->mk, data->ck, data->ick) < 0)
187 wpa_printf(MSG_DEBUG, "EAP-PAX: PAX_STD-2 (sending)");
189 plen = 2 + EAP_PAX_RAND_LEN + 2 + data->cid_len + 2 + EAP_PAX_MAC_LEN +
191 resp = eap_pax_alloc_resp(req, id, EAP_PAX_OP_STD_2, plen);
195 wpabuf_put_be16(resp, EAP_PAX_RAND_LEN);
196 wpabuf_put_data(resp, data->rand.r.y, EAP_PAX_RAND_LEN);
197 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: B = Y (client rand)",
198 data->rand.r.y, EAP_PAX_RAND_LEN);
200 wpabuf_put_be16(resp, data->cid_len);
201 wpabuf_put_data(resp, data->cid, data->cid_len);
202 wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-PAX: CID",
203 (u8 *) data->cid, data->cid_len);
205 wpabuf_put_be16(resp, EAP_PAX_MAC_LEN);
206 rpos = wpabuf_put(resp, EAP_PAX_MAC_LEN);
207 eap_pax_mac(req->mac_id, data->ck, EAP_PAX_CK_LEN,
208 data->rand.r.x, EAP_PAX_RAND_LEN,
209 data->rand.r.y, EAP_PAX_RAND_LEN,
210 (u8 *) data->cid, data->cid_len, rpos);
211 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: MAC_CK(A, B, CID)",
212 rpos, EAP_PAX_MAC_LEN);
214 /* Optional ADE could be added here, if needed */
216 rpos = wpabuf_put(resp, EAP_PAX_ICV_LEN);
217 eap_pax_mac(req->mac_id, data->ick, EAP_PAX_ICK_LEN,
218 wpabuf_head(resp), wpabuf_len(resp) - EAP_PAX_ICV_LEN,
219 NULL, 0, NULL, 0, rpos);
220 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", rpos, EAP_PAX_ICV_LEN);
222 data->state = PAX_STD_2_SENT;
223 data->mac_id = req->mac_id;
224 data->dh_group_id = req->dh_group_id;
225 data->public_key_id = req->public_key_id;
231 static struct wpabuf * eap_pax_process_std_3(struct eap_pax_data *data,
232 struct eap_method_ret *ret, u8 id,
233 const struct eap_pax_hdr *req,
237 u8 *rpos, mac[EAP_PAX_MAC_LEN];
241 wpa_printf(MSG_DEBUG, "EAP-PAX: PAX_STD-3 (received)");
243 if (data->state != PAX_STD_2_SENT) {
244 wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-3 received in "
245 "unexpected state (%d) - ignored", data->state);
250 if (req->flags & EAP_PAX_FLAGS_CE) {
251 wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-3 with CE flag set - "
257 left = req_plen - sizeof(*req);
259 if (left < 2 + EAP_PAX_MAC_LEN) {
260 wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-3 with too short "
266 pos = (const u8 *) (req + 1);
267 if (WPA_GET_BE16(pos) != EAP_PAX_MAC_LEN) {
268 wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-3 with incorrect "
269 "MAC_CK length %d (expected %d)",
270 WPA_GET_BE16(pos), EAP_PAX_MAC_LEN);
276 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: MAC_CK(B, CID)",
277 pos, EAP_PAX_MAC_LEN);
278 eap_pax_mac(data->mac_id, data->ck, EAP_PAX_CK_LEN,
279 data->rand.r.y, EAP_PAX_RAND_LEN,
280 (u8 *) data->cid, data->cid_len, NULL, 0, mac);
281 if (os_memcmp(pos, mac, EAP_PAX_MAC_LEN) != 0) {
282 wpa_printf(MSG_INFO, "EAP-PAX: Invalid MAC_CK(B, CID) "
284 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: expected MAC_CK(B, CID)",
285 mac, EAP_PAX_MAC_LEN);
286 ret->methodState = METHOD_DONE;
287 ret->decision = DECISION_FAIL;
291 pos += EAP_PAX_MAC_LEN;
292 left -= EAP_PAX_MAC_LEN;
295 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ignored extra payload",
299 wpa_printf(MSG_DEBUG, "EAP-PAX: PAX-ACK (sending)");
301 resp = eap_pax_alloc_resp(req, id, EAP_PAX_OP_ACK, EAP_PAX_ICV_LEN);
305 /* Optional ADE could be added here, if needed */
307 rpos = wpabuf_put(resp, EAP_PAX_ICV_LEN);
308 eap_pax_mac(data->mac_id, data->ick, EAP_PAX_ICK_LEN,
309 wpabuf_head(resp), wpabuf_len(resp) - EAP_PAX_ICV_LEN,
310 NULL, 0, NULL, 0, rpos);
311 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", rpos, EAP_PAX_ICV_LEN);
313 data->state = PAX_DONE;
314 ret->methodState = METHOD_DONE;
315 ret->decision = DECISION_UNCOND_SUCC;
316 ret->allowNotifications = FALSE;
322 static struct wpabuf * eap_pax_process(struct eap_sm *sm, void *priv,
323 struct eap_method_ret *ret,
324 const struct wpabuf *reqData)
326 struct eap_pax_data *data = priv;
327 const struct eap_pax_hdr *req;
329 u8 icvbuf[EAP_PAX_ICV_LEN], id;
334 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PAX, reqData, &len);
335 if (pos == NULL || len < EAP_PAX_ICV_LEN) {
339 id = eap_get_id(reqData);
340 req = (const struct eap_pax_hdr *) pos;
341 flen = len - EAP_PAX_ICV_LEN;
342 mlen = wpabuf_len(reqData) - EAP_PAX_ICV_LEN;
344 wpa_printf(MSG_DEBUG, "EAP-PAX: received frame: op_code 0x%x "
345 "flags 0x%x mac_id 0x%x dh_group_id 0x%x "
346 "public_key_id 0x%x",
347 req->op_code, req->flags, req->mac_id, req->dh_group_id,
349 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: received payload",
350 pos, len - EAP_PAX_ICV_LEN);
352 if (data->state != PAX_INIT && data->mac_id != req->mac_id) {
353 wpa_printf(MSG_INFO, "EAP-PAX: MAC ID changed during "
354 "authentication (was 0x%d, is 0x%d)",
355 data->mac_id, req->mac_id);
360 if (data->state != PAX_INIT && data->dh_group_id != req->dh_group_id) {
361 wpa_printf(MSG_INFO, "EAP-PAX: DH Group ID changed during "
362 "authentication (was 0x%d, is 0x%d)",
363 data->dh_group_id, req->dh_group_id);
368 if (data->state != PAX_INIT &&
369 data->public_key_id != req->public_key_id) {
370 wpa_printf(MSG_INFO, "EAP-PAX: Public Key ID changed during "
371 "authentication (was 0x%d, is 0x%d)",
372 data->public_key_id, req->public_key_id);
377 /* TODO: add support EAP_PAX_HMAC_SHA256_128 */
378 if (req->mac_id != EAP_PAX_MAC_HMAC_SHA1_128) {
379 wpa_printf(MSG_INFO, "EAP-PAX: Unsupported MAC ID 0x%x",
385 if (req->dh_group_id != EAP_PAX_DH_GROUP_NONE) {
386 wpa_printf(MSG_INFO, "EAP-PAX: Unsupported DH Group ID 0x%x",
392 if (req->public_key_id != EAP_PAX_PUBLIC_KEY_NONE) {
393 wpa_printf(MSG_INFO, "EAP-PAX: Unsupported Public Key ID 0x%x",
399 if (req->flags & EAP_PAX_FLAGS_MF) {
400 /* TODO: add support for reassembling fragments */
401 wpa_printf(MSG_INFO, "EAP-PAX: fragmentation not supported - "
407 icv = pos + len - EAP_PAX_ICV_LEN;
408 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", icv, EAP_PAX_ICV_LEN);
409 if (req->op_code == EAP_PAX_OP_STD_1) {
410 eap_pax_mac(req->mac_id, (u8 *) "", 0,
411 wpabuf_head(reqData), mlen, NULL, 0, NULL, 0,
414 eap_pax_mac(req->mac_id, data->ick, EAP_PAX_ICK_LEN,
415 wpabuf_head(reqData), mlen, NULL, 0, NULL, 0,
418 if (os_memcmp(icv, icvbuf, EAP_PAX_ICV_LEN) != 0) {
419 wpa_printf(MSG_DEBUG, "EAP-PAX: invalid ICV - ignoring the "
421 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: expected ICV",
422 icvbuf, EAP_PAX_ICV_LEN);
428 ret->methodState = METHOD_MAY_CONT;
429 ret->decision = DECISION_FAIL;
430 ret->allowNotifications = TRUE;
432 switch (req->op_code) {
433 case EAP_PAX_OP_STD_1:
434 resp = eap_pax_process_std_1(data, ret, id, req, flen);
436 case EAP_PAX_OP_STD_3:
437 resp = eap_pax_process_std_3(data, ret, id, req, flen);
440 wpa_printf(MSG_DEBUG, "EAP-PAX: ignoring message with unknown "
441 "op_code %d", req->op_code);
446 if (ret->methodState == METHOD_DONE) {
447 ret->allowNotifications = FALSE;
454 static Boolean eap_pax_isKeyAvailable(struct eap_sm *sm, void *priv)
456 struct eap_pax_data *data = priv;
457 return data->state == PAX_DONE;
461 static u8 * eap_pax_getKey(struct eap_sm *sm, void *priv, size_t *len)
463 struct eap_pax_data *data = priv;
466 if (data->state != PAX_DONE)
469 key = os_malloc(EAP_MSK_LEN);
474 eap_pax_kdf(data->mac_id, data->mk, EAP_PAX_MK_LEN,
475 "Master Session Key", data->rand.e, 2 * EAP_PAX_RAND_LEN,
482 static u8 * eap_pax_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
484 struct eap_pax_data *data = priv;
487 if (data->state != PAX_DONE)
490 key = os_malloc(EAP_EMSK_LEN);
495 eap_pax_kdf(data->mac_id, data->mk, EAP_PAX_MK_LEN,
496 "Extended Master Session Key",
497 data->rand.e, 2 * EAP_PAX_RAND_LEN,
504 int eap_peer_pax_register(void)
506 struct eap_method *eap;
509 eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
510 EAP_VENDOR_IETF, EAP_TYPE_PAX, "PAX");
514 eap->init = eap_pax_init;
515 eap->deinit = eap_pax_deinit;
516 eap->process = eap_pax_process;
517 eap->isKeyAvailable = eap_pax_isKeyAvailable;
518 eap->getKey = eap_pax_getKey;
519 eap->get_emsk = eap_pax_get_emsk;
521 ret = eap_peer_method_register(eap);
523 eap_peer_method_free(eap);