2 * EAP peer method: EAP-PAX (RFC 4746)
3 * Copyright (c) 2005-2008, Jouni Malinen <j@w1.fi>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
9 * Alternatively, this software may be distributed under the terms of BSD
12 * See README and COPYING for more details.
18 #include "eap_peer/eap_i.h"
19 #include "eap_common/eap_pax_common.h"
24 * Note: only PAX_STD subprotocol is currently supported
26 * TODO: Add support with PAX_SEC with the mandatory to implement ciphersuite
27 * (HMAC_SHA1_128, IANA DH Group 14 (2048 bits), RSA-PKCS1-V1_5) and
28 * recommended ciphersuite (HMAC_SHA256_128, IANA DH Group 15 (3072 bits),
33 enum { PAX_INIT, PAX_STD_2_SENT, PAX_DONE } state;
34 u8 mac_id, dh_group_id, public_key_id;
36 u8 e[2 * EAP_PAX_RAND_LEN];
38 u8 x[EAP_PAX_RAND_LEN]; /* server rand */
39 u8 y[EAP_PAX_RAND_LEN]; /* client rand */
44 u8 ak[EAP_PAX_AK_LEN];
45 u8 mk[EAP_PAX_MK_LEN];
46 u8 ck[EAP_PAX_CK_LEN];
47 u8 ick[EAP_PAX_ICK_LEN];
51 static void eap_pax_deinit(struct eap_sm *sm, void *priv);
54 static void * eap_pax_init(struct eap_sm *sm)
56 struct eap_pax_data *data;
57 const u8 *identity, *password;
58 size_t identity_len, password_len;
60 identity = eap_get_config_identity(sm, &identity_len);
61 password = eap_get_config_password(sm, &password_len);
62 if (!identity || !password) {
63 wpa_printf(MSG_INFO, "EAP-PAX: CID (nai) or key (password) "
68 if (password_len != EAP_PAX_AK_LEN) {
69 wpa_printf(MSG_INFO, "EAP-PAX: Invalid PSK length");
73 data = os_zalloc(sizeof(*data));
76 data->state = PAX_INIT;
78 data->cid = os_malloc(identity_len);
79 if (data->cid == NULL) {
80 eap_pax_deinit(sm, data);
83 os_memcpy(data->cid, identity, identity_len);
84 data->cid_len = identity_len;
86 os_memcpy(data->ak, password, EAP_PAX_AK_LEN);
92 static void eap_pax_deinit(struct eap_sm *sm, void *priv)
94 struct eap_pax_data *data = priv;
100 static struct wpabuf * eap_pax_alloc_resp(const struct eap_pax_hdr *req,
101 u8 id, u8 op_code, size_t plen)
104 struct eap_pax_hdr *pax;
106 resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PAX,
107 sizeof(*pax) + plen, EAP_CODE_RESPONSE, id);
111 pax = wpabuf_put(resp, sizeof(*pax));
112 pax->op_code = op_code;
114 pax->mac_id = req->mac_id;
115 pax->dh_group_id = req->dh_group_id;
116 pax->public_key_id = req->public_key_id;
122 static struct wpabuf * eap_pax_process_std_1(struct eap_pax_data *data,
123 struct eap_method_ret *ret, u8 id,
124 const struct eap_pax_hdr *req,
132 wpa_printf(MSG_DEBUG, "EAP-PAX: PAX_STD-1 (received)");
134 if (data->state != PAX_INIT) {
135 wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-1 received in "
136 "unexpected state (%d) - ignored", data->state);
141 if (req->flags & EAP_PAX_FLAGS_CE) {
142 wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-1 with CE flag set - "
148 left = req_plen - sizeof(*req);
150 if (left < 2 + EAP_PAX_RAND_LEN) {
151 wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-1 with too short "
157 pos = (const u8 *) (req + 1);
158 if (WPA_GET_BE16(pos) != EAP_PAX_RAND_LEN) {
159 wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-1 with incorrect A "
160 "length %d (expected %d)",
161 WPA_GET_BE16(pos), EAP_PAX_RAND_LEN);
168 os_memcpy(data->rand.r.x, pos, EAP_PAX_RAND_LEN);
169 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: X (server rand)",
170 data->rand.r.x, EAP_PAX_RAND_LEN);
171 pos += EAP_PAX_RAND_LEN;
172 left -= EAP_PAX_RAND_LEN;
175 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ignored extra payload",
179 if (os_get_random(data->rand.r.y, EAP_PAX_RAND_LEN)) {
180 wpa_printf(MSG_ERROR, "EAP-PAX: Failed to get random data");
184 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: Y (client rand)",
185 data->rand.r.y, EAP_PAX_RAND_LEN);
187 if (eap_pax_initial_key_derivation(req->mac_id, data->ak, data->rand.e,
188 data->mk, data->ck, data->ick) < 0)
194 wpa_printf(MSG_DEBUG, "EAP-PAX: PAX_STD-2 (sending)");
196 plen = 2 + EAP_PAX_RAND_LEN + 2 + data->cid_len + 2 + EAP_PAX_MAC_LEN +
198 resp = eap_pax_alloc_resp(req, id, EAP_PAX_OP_STD_2, plen);
202 wpabuf_put_be16(resp, EAP_PAX_RAND_LEN);
203 wpabuf_put_data(resp, data->rand.r.y, EAP_PAX_RAND_LEN);
204 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: B = Y (client rand)",
205 data->rand.r.y, EAP_PAX_RAND_LEN);
207 wpabuf_put_be16(resp, data->cid_len);
208 wpabuf_put_data(resp, data->cid, data->cid_len);
209 wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-PAX: CID",
210 (u8 *) data->cid, data->cid_len);
212 wpabuf_put_be16(resp, EAP_PAX_MAC_LEN);
213 rpos = wpabuf_put(resp, EAP_PAX_MAC_LEN);
214 eap_pax_mac(req->mac_id, data->ck, EAP_PAX_CK_LEN,
215 data->rand.r.x, EAP_PAX_RAND_LEN,
216 data->rand.r.y, EAP_PAX_RAND_LEN,
217 (u8 *) data->cid, data->cid_len, rpos);
218 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: MAC_CK(A, B, CID)",
219 rpos, EAP_PAX_MAC_LEN);
221 /* Optional ADE could be added here, if needed */
223 rpos = wpabuf_put(resp, EAP_PAX_ICV_LEN);
224 eap_pax_mac(req->mac_id, data->ick, EAP_PAX_ICK_LEN,
225 wpabuf_head(resp), wpabuf_len(resp) - EAP_PAX_ICV_LEN,
226 NULL, 0, NULL, 0, rpos);
227 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", rpos, EAP_PAX_ICV_LEN);
229 data->state = PAX_STD_2_SENT;
230 data->mac_id = req->mac_id;
231 data->dh_group_id = req->dh_group_id;
232 data->public_key_id = req->public_key_id;
238 static struct wpabuf * eap_pax_process_std_3(struct eap_pax_data *data,
239 struct eap_method_ret *ret, u8 id,
240 const struct eap_pax_hdr *req,
244 u8 *rpos, mac[EAP_PAX_MAC_LEN];
248 wpa_printf(MSG_DEBUG, "EAP-PAX: PAX_STD-3 (received)");
250 if (data->state != PAX_STD_2_SENT) {
251 wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-3 received in "
252 "unexpected state (%d) - ignored", data->state);
257 if (req->flags & EAP_PAX_FLAGS_CE) {
258 wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-3 with CE flag set - "
264 left = req_plen - sizeof(*req);
266 if (left < 2 + EAP_PAX_MAC_LEN) {
267 wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-3 with too short "
273 pos = (const u8 *) (req + 1);
274 if (WPA_GET_BE16(pos) != EAP_PAX_MAC_LEN) {
275 wpa_printf(MSG_INFO, "EAP-PAX: PAX_STD-3 with incorrect "
276 "MAC_CK length %d (expected %d)",
277 WPA_GET_BE16(pos), EAP_PAX_MAC_LEN);
283 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: MAC_CK(B, CID)",
284 pos, EAP_PAX_MAC_LEN);
285 eap_pax_mac(data->mac_id, data->ck, EAP_PAX_CK_LEN,
286 data->rand.r.y, EAP_PAX_RAND_LEN,
287 (u8 *) data->cid, data->cid_len, NULL, 0, mac);
288 if (os_memcmp(pos, mac, EAP_PAX_MAC_LEN) != 0) {
289 wpa_printf(MSG_INFO, "EAP-PAX: Invalid MAC_CK(B, CID) "
291 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: expected MAC_CK(B, CID)",
292 mac, EAP_PAX_MAC_LEN);
293 ret->methodState = METHOD_DONE;
294 ret->decision = DECISION_FAIL;
298 pos += EAP_PAX_MAC_LEN;
299 left -= EAP_PAX_MAC_LEN;
302 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ignored extra payload",
306 wpa_printf(MSG_DEBUG, "EAP-PAX: PAX-ACK (sending)");
308 resp = eap_pax_alloc_resp(req, id, EAP_PAX_OP_ACK, EAP_PAX_ICV_LEN);
312 /* Optional ADE could be added here, if needed */
314 rpos = wpabuf_put(resp, EAP_PAX_ICV_LEN);
315 eap_pax_mac(data->mac_id, data->ick, EAP_PAX_ICK_LEN,
316 wpabuf_head(resp), wpabuf_len(resp) - EAP_PAX_ICV_LEN,
317 NULL, 0, NULL, 0, rpos);
318 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", rpos, EAP_PAX_ICV_LEN);
320 data->state = PAX_DONE;
321 ret->methodState = METHOD_DONE;
322 ret->decision = DECISION_UNCOND_SUCC;
323 ret->allowNotifications = FALSE;
329 static struct wpabuf * eap_pax_process(struct eap_sm *sm, void *priv,
330 struct eap_method_ret *ret,
331 const struct wpabuf *reqData)
333 struct eap_pax_data *data = priv;
334 const struct eap_pax_hdr *req;
336 u8 icvbuf[EAP_PAX_ICV_LEN], id;
341 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PAX, reqData, &len);
342 if (pos == NULL || len < EAP_PAX_ICV_LEN) {
346 id = eap_get_id(reqData);
347 req = (const struct eap_pax_hdr *) pos;
348 flen = len - EAP_PAX_ICV_LEN;
349 mlen = wpabuf_len(reqData) - EAP_PAX_ICV_LEN;
351 wpa_printf(MSG_DEBUG, "EAP-PAX: received frame: op_code 0x%x "
352 "flags 0x%x mac_id 0x%x dh_group_id 0x%x "
353 "public_key_id 0x%x",
354 req->op_code, req->flags, req->mac_id, req->dh_group_id,
356 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: received payload",
357 pos, len - EAP_PAX_ICV_LEN);
359 if (data->state != PAX_INIT && data->mac_id != req->mac_id) {
360 wpa_printf(MSG_INFO, "EAP-PAX: MAC ID changed during "
361 "authentication (was 0x%d, is 0x%d)",
362 data->mac_id, req->mac_id);
367 if (data->state != PAX_INIT && data->dh_group_id != req->dh_group_id) {
368 wpa_printf(MSG_INFO, "EAP-PAX: DH Group ID changed during "
369 "authentication (was 0x%d, is 0x%d)",
370 data->dh_group_id, req->dh_group_id);
375 if (data->state != PAX_INIT &&
376 data->public_key_id != req->public_key_id) {
377 wpa_printf(MSG_INFO, "EAP-PAX: Public Key ID changed during "
378 "authentication (was 0x%d, is 0x%d)",
379 data->public_key_id, req->public_key_id);
384 /* TODO: add support EAP_PAX_HMAC_SHA256_128 */
385 if (req->mac_id != EAP_PAX_MAC_HMAC_SHA1_128) {
386 wpa_printf(MSG_INFO, "EAP-PAX: Unsupported MAC ID 0x%x",
392 if (req->dh_group_id != EAP_PAX_DH_GROUP_NONE) {
393 wpa_printf(MSG_INFO, "EAP-PAX: Unsupported DH Group ID 0x%x",
399 if (req->public_key_id != EAP_PAX_PUBLIC_KEY_NONE) {
400 wpa_printf(MSG_INFO, "EAP-PAX: Unsupported Public Key ID 0x%x",
406 if (req->flags & EAP_PAX_FLAGS_MF) {
407 /* TODO: add support for reassembling fragments */
408 wpa_printf(MSG_INFO, "EAP-PAX: fragmentation not supported - "
414 icv = pos + len - EAP_PAX_ICV_LEN;
415 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", icv, EAP_PAX_ICV_LEN);
416 if (req->op_code == EAP_PAX_OP_STD_1) {
417 eap_pax_mac(req->mac_id, (u8 *) "", 0,
418 wpabuf_head(reqData), mlen, NULL, 0, NULL, 0,
421 eap_pax_mac(req->mac_id, data->ick, EAP_PAX_ICK_LEN,
422 wpabuf_head(reqData), mlen, NULL, 0, NULL, 0,
425 if (os_memcmp(icv, icvbuf, EAP_PAX_ICV_LEN) != 0) {
426 wpa_printf(MSG_DEBUG, "EAP-PAX: invalid ICV - ignoring the "
428 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: expected ICV",
429 icvbuf, EAP_PAX_ICV_LEN);
435 ret->methodState = METHOD_MAY_CONT;
436 ret->decision = DECISION_FAIL;
437 ret->allowNotifications = TRUE;
439 switch (req->op_code) {
440 case EAP_PAX_OP_STD_1:
441 resp = eap_pax_process_std_1(data, ret, id, req, flen);
443 case EAP_PAX_OP_STD_3:
444 resp = eap_pax_process_std_3(data, ret, id, req, flen);
447 wpa_printf(MSG_DEBUG, "EAP-PAX: ignoring message with unknown "
448 "op_code %d", req->op_code);
453 if (ret->methodState == METHOD_DONE) {
454 ret->allowNotifications = FALSE;
461 static Boolean eap_pax_isKeyAvailable(struct eap_sm *sm, void *priv)
463 struct eap_pax_data *data = priv;
464 return data->state == PAX_DONE;
468 static u8 * eap_pax_getKey(struct eap_sm *sm, void *priv, size_t *len)
470 struct eap_pax_data *data = priv;
473 if (data->state != PAX_DONE)
476 key = os_malloc(EAP_MSK_LEN);
481 eap_pax_kdf(data->mac_id, data->mk, EAP_PAX_MK_LEN,
482 "Master Session Key", data->rand.e, 2 * EAP_PAX_RAND_LEN,
489 static u8 * eap_pax_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
491 struct eap_pax_data *data = priv;
494 if (data->state != PAX_DONE)
497 key = os_malloc(EAP_EMSK_LEN);
502 eap_pax_kdf(data->mac_id, data->mk, EAP_PAX_MK_LEN,
503 "Extended Master Session Key",
504 data->rand.e, 2 * EAP_PAX_RAND_LEN,
511 int eap_peer_pax_register(void)
513 struct eap_method *eap;
516 eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
517 EAP_VENDOR_IETF, EAP_TYPE_PAX, "PAX");
521 eap->init = eap_pax_init;
522 eap->deinit = eap_pax_deinit;
523 eap->process = eap_pax_process;
524 eap->isKeyAvailable = eap_pax_isKeyAvailable;
525 eap->getKey = eap_pax_getKey;
526 eap->get_emsk = eap_pax_get_emsk;
528 ret = eap_peer_method_register(eap);
530 eap_peer_method_free(eap);