2 * hostapd / EAP-PAX (RFC 4746) server
3 * Copyright (c) 2005-2007, 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_server/eap_i.h"
14 #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_STD_1, PAX_STD_3, SUCCESS, FAILURE } state;
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 */
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];
46 static void * eap_pax_init(struct eap_sm *sm)
48 struct eap_pax_data *data;
50 data = os_zalloc(sizeof(*data));
53 data->state = PAX_STD_1;
55 * TODO: make this configurable once EAP_PAX_HMAC_SHA256_128 is
58 data->mac_id = EAP_PAX_MAC_HMAC_SHA1_128;
64 static void eap_pax_reset(struct eap_sm *sm, void *priv)
66 struct eap_pax_data *data = priv;
68 bin_clear_free(data, sizeof(*data));
72 static struct wpabuf * eap_pax_build_std_1(struct eap_sm *sm,
73 struct eap_pax_data *data, u8 id)
76 struct eap_pax_hdr *pax;
79 wpa_printf(MSG_DEBUG, "EAP-PAX: PAX_STD-1 (sending)");
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;
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);
91 wpa_printf(MSG_ERROR, "EAP-PAX: Failed to allocate memory "
93 data->state = FAILURE;
97 pax = wpabuf_put(req, sizeof(*pax));
98 pax->op_code = EAP_PAX_OP_STD_1;
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;
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);
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);
119 static struct wpabuf * eap_pax_build_std_3(struct eap_sm *sm,
120 struct eap_pax_data *data, u8 id)
123 struct eap_pax_hdr *pax;
126 wpa_printf(MSG_DEBUG, "EAP-PAX: PAX_STD-3 (sending)");
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);
132 wpa_printf(MSG_ERROR, "EAP-PAX: Failed to allocate memory "
134 data->state = FAILURE;
138 pax = wpabuf_put(req, sizeof(*pax));
139 pax->op_code = EAP_PAX_OP_STD_3;
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;
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);
153 /* Optional ADE could be added here, if needed */
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);
165 static struct wpabuf * eap_pax_buildReq(struct eap_sm *sm, void *priv, u8 id)
167 struct eap_pax_data *data = priv;
169 switch (data->state) {
171 return eap_pax_build_std_1(sm, data, id);
173 return eap_pax_build_std_3(sm, data, id);
175 wpa_printf(MSG_DEBUG, "EAP-PAX: Unknown state %d in buildReq",
183 static Boolean eap_pax_check(struct eap_sm *sm, void *priv,
184 struct wpabuf *respData)
186 struct eap_pax_data *data = priv;
187 struct eap_pax_hdr *resp;
190 u8 icvbuf[EAP_PAX_ICV_LEN], *icv;
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");
198 mlen = sizeof(struct eap_hdr) + 1 + len;
199 resp = (struct eap_pax_hdr *) pos;
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);
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);
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);
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",
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);
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,
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);
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");
255 if (resp->flags & EAP_PAX_FLAGS_CE) {
256 wpa_printf(MSG_INFO, "EAP-PAX: Unexpected CE flag");
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");
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);
283 static void eap_pax_process_std_2(struct eap_sm *sm,
284 struct eap_pax_data *data,
285 struct wpabuf *respData)
287 struct eap_pax_hdr *resp;
288 u8 mac[EAP_PAX_MAC_LEN], icvbuf[EAP_PAX_ICV_LEN];
290 size_t len, left, cid_len;
293 if (data->state != PAX_STD_1)
296 wpa_printf(MSG_DEBUG, "EAP-PAX: Received PAX_STD-2");
298 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PAX, respData, &len);
299 if (pos == NULL || len < sizeof(*resp) + EAP_PAX_ICV_LEN)
302 resp = (struct eap_pax_hdr *) pos;
303 pos = (u8 *) (resp + 1);
304 left = len - sizeof(*resp);
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)");
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;
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)");
323 cid_len = WPA_GET_BE16(pos);
324 if (cid_len > 1500) {
325 wpa_printf(MSG_INFO, "EAP-PAX: Too long CID");
328 data->cid_len = cid_len;
330 data->cid = os_malloc(data->cid_len);
331 if (data->cid == NULL) {
332 wpa_printf(MSG_INFO, "EAP-PAX: Failed to allocate memory for "
336 os_memcpy(data->cid, pos + 2, data->cid_len);
337 pos += 2 + data->cid_len;
338 left -= 2 + data->cid_len;
339 wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-PAX: CID",
340 (u8 *) data->cid, data->cid_len);
342 if (left < 2 + EAP_PAX_MAC_LEN ||
343 WPA_GET_BE16(pos) != EAP_PAX_MAC_LEN) {
344 wpa_printf(MSG_INFO, "EAP-PAX: Too short PAX_STD-2 (MAC_CK)");
349 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: MAC_CK(A, B, CID)",
350 pos, EAP_PAX_MAC_LEN);
352 if (eap_user_get(sm, (u8 *) data->cid, data->cid_len, 0) < 0) {
353 wpa_hexdump_ascii(MSG_DEBUG, "EAP-PAX: unknown CID",
354 (u8 *) data->cid, data->cid_len);
355 data->state = FAILURE;
360 i < EAP_MAX_METHODS &&
361 (sm->user->methods[i].vendor != EAP_VENDOR_IETF ||
362 sm->user->methods[i].method != EAP_TYPE_NONE);
364 if (sm->user->methods[i].vendor == EAP_VENDOR_IETF &&
365 sm->user->methods[i].method == EAP_TYPE_PAX)
369 if (i >= EAP_MAX_METHODS ||
370 sm->user->methods[i].vendor != EAP_VENDOR_IETF ||
371 sm->user->methods[i].method != EAP_TYPE_PAX) {
372 wpa_hexdump_ascii(MSG_DEBUG,
373 "EAP-PAX: EAP-PAX not enabled for CID",
374 (u8 *) data->cid, data->cid_len);
375 data->state = FAILURE;
379 if (sm->user->password == NULL ||
380 sm->user->password_len != EAP_PAX_AK_LEN) {
381 wpa_hexdump_ascii(MSG_DEBUG, "EAP-PAX: invalid password in "
382 "user database for CID",
383 (u8 *) data->cid, data->cid_len);
384 data->state = FAILURE;
387 os_memcpy(data->ak, sm->user->password, EAP_PAX_AK_LEN);
389 if (eap_pax_initial_key_derivation(data->mac_id, data->ak,
390 data->rand.e, data->mk, data->ck,
391 data->ick, data->mid) < 0) {
392 wpa_printf(MSG_INFO, "EAP-PAX: Failed to complete initial "
394 data->state = FAILURE;
399 eap_pax_mac(data->mac_id, data->ck, EAP_PAX_CK_LEN,
400 data->rand.r.x, EAP_PAX_RAND_LEN,
401 data->rand.r.y, EAP_PAX_RAND_LEN,
402 (u8 *) data->cid, data->cid_len, mac);
403 if (os_memcmp_const(mac, pos, EAP_PAX_MAC_LEN) != 0) {
404 wpa_printf(MSG_INFO, "EAP-PAX: Invalid MAC_CK(A, B, CID) in "
406 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: Expected MAC_CK(A, B, CID)",
407 mac, EAP_PAX_MAC_LEN);
408 data->state = FAILURE;
412 pos += EAP_PAX_MAC_LEN;
413 left -= EAP_PAX_MAC_LEN;
415 if (left < EAP_PAX_ICV_LEN) {
416 wpa_printf(MSG_INFO, "EAP-PAX: Too short ICV (%lu) in "
417 "PAX_STD-2", (unsigned long) left);
420 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", pos, EAP_PAX_ICV_LEN);
421 eap_pax_mac(data->mac_id, data->ick, EAP_PAX_ICK_LEN,
422 wpabuf_head(respData),
423 wpabuf_len(respData) - EAP_PAX_ICV_LEN, NULL, 0, NULL, 0,
425 if (os_memcmp_const(icvbuf, pos, EAP_PAX_ICV_LEN) != 0) {
426 wpa_printf(MSG_INFO, "EAP-PAX: Invalid ICV in PAX_STD-2");
427 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: Expected ICV",
428 icvbuf, EAP_PAX_ICV_LEN);
431 pos += EAP_PAX_ICV_LEN;
432 left -= EAP_PAX_ICV_LEN;
435 wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ignored extra payload",
439 data->state = PAX_STD_3;
443 static void eap_pax_process_ack(struct eap_sm *sm,
444 struct eap_pax_data *data,
445 struct wpabuf *respData)
447 if (data->state != PAX_STD_3)
450 wpa_printf(MSG_DEBUG, "EAP-PAX: Received PAX-ACK - authentication "
451 "completed successfully");
452 data->state = SUCCESS;
456 static void eap_pax_process(struct eap_sm *sm, void *priv,
457 struct wpabuf *respData)
459 struct eap_pax_data *data = priv;
460 struct eap_pax_hdr *resp;
464 if (sm->user == NULL || sm->user->password == NULL) {
465 wpa_printf(MSG_INFO, "EAP-PAX: Plaintext password not "
467 data->state = FAILURE;
471 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PAX, respData, &len);
472 if (pos == NULL || len < sizeof(*resp))
475 resp = (struct eap_pax_hdr *) pos;
477 switch (resp->op_code) {
478 case EAP_PAX_OP_STD_2:
479 eap_pax_process_std_2(sm, data, respData);
482 eap_pax_process_ack(sm, data, respData);
488 static Boolean eap_pax_isDone(struct eap_sm *sm, void *priv)
490 struct eap_pax_data *data = priv;
491 return data->state == SUCCESS || data->state == FAILURE;
495 static u8 * eap_pax_getKey(struct eap_sm *sm, void *priv, size_t *len)
497 struct eap_pax_data *data = priv;
500 if (data->state != SUCCESS)
503 key = os_malloc(EAP_MSK_LEN);
508 eap_pax_kdf(data->mac_id, data->mk, EAP_PAX_MK_LEN,
509 "Master Session Key", data->rand.e, 2 * EAP_PAX_RAND_LEN,
516 static u8 * eap_pax_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
518 struct eap_pax_data *data = priv;
521 if (data->state != SUCCESS)
524 key = os_malloc(EAP_EMSK_LEN);
529 eap_pax_kdf(data->mac_id, data->mk, EAP_PAX_MK_LEN,
530 "Extended Master Session Key",
531 data->rand.e, 2 * EAP_PAX_RAND_LEN,
538 static Boolean eap_pax_isSuccess(struct eap_sm *sm, void *priv)
540 struct eap_pax_data *data = priv;
541 return data->state == SUCCESS;
545 static u8 * eap_pax_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
547 struct eap_pax_data *data = priv;
550 if (data->state != SUCCESS)
553 sid = os_malloc(1 + EAP_PAX_MID_LEN);
557 *len = 1 + EAP_PAX_MID_LEN;
558 sid[0] = EAP_TYPE_PAX;
559 os_memcpy(sid + 1, data->mid, EAP_PAX_MID_LEN);
565 int eap_server_pax_register(void)
567 struct eap_method *eap;
570 eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
571 EAP_VENDOR_IETF, EAP_TYPE_PAX, "PAX");
575 eap->init = eap_pax_init;
576 eap->reset = eap_pax_reset;
577 eap->buildReq = eap_pax_buildReq;
578 eap->check = eap_pax_check;
579 eap->process = eap_pax_process;
580 eap->isDone = eap_pax_isDone;
581 eap->getKey = eap_pax_getKey;
582 eap->isSuccess = eap_pax_isSuccess;
583 eap->get_emsk = eap_pax_get_emsk;
584 eap->getSessionId = eap_pax_get_session_id;
586 ret = eap_server_method_register(eap);
588 eap_server_method_free(eap);