2 * hostapd / EAP-MSCHAPv2 (draft-kamath-pppext-eap-mschapv2-00.txt) server
3 * Copyright (c) 2004-2007, 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 "crypto/ms_funcs.h"
22 struct eap_mschapv2_hdr {
23 u8 op_code; /* MSCHAPV2_OP_* */
24 u8 mschapv2_id; /* must be changed for challenges, but not for
26 u8 ms_length[2]; /* Note: misaligned; length - 5 */
27 /* followed by data */
30 #define MSCHAPV2_OP_CHALLENGE 1
31 #define MSCHAPV2_OP_RESPONSE 2
32 #define MSCHAPV2_OP_SUCCESS 3
33 #define MSCHAPV2_OP_FAILURE 4
34 #define MSCHAPV2_OP_CHANGE_PASSWORD 7
36 #define MSCHAPV2_RESP_LEN 49
38 #define ERROR_RESTRICTED_LOGON_HOURS 646
39 #define ERROR_ACCT_DISABLED 647
40 #define ERROR_PASSWD_EXPIRED 648
41 #define ERROR_NO_DIALIN_PERMISSION 649
42 #define ERROR_AUTHENTICATION_FAILURE 691
43 #define ERROR_CHANGING_PASSWORD 709
45 #define PASSWD_CHANGE_CHAL_LEN 16
46 #define MSCHAPV2_KEY_LEN 16
49 #define CHALLENGE_LEN 16
51 struct eap_mschapv2_data {
52 u8 auth_challenge[CHALLENGE_LEN];
53 int auth_challenge_from_tls;
56 enum { CHALLENGE, SUCCESS_REQ, FAILURE_REQ, SUCCESS, FAILURE } state;
63 static void * eap_mschapv2_init(struct eap_sm *sm)
65 struct eap_mschapv2_data *data;
67 data = os_zalloc(sizeof(*data));
70 data->state = CHALLENGE;
72 if (sm->auth_challenge) {
73 os_memcpy(data->auth_challenge, sm->auth_challenge,
75 data->auth_challenge_from_tls = 1;
78 if (sm->peer_challenge) {
79 data->peer_challenge = os_malloc(CHALLENGE_LEN);
80 if (data->peer_challenge == NULL) {
84 os_memcpy(data->peer_challenge, sm->peer_challenge,
92 static void eap_mschapv2_reset(struct eap_sm *sm, void *priv)
94 struct eap_mschapv2_data *data = priv;
98 os_free(data->peer_challenge);
103 static struct wpabuf * eap_mschapv2_build_challenge(
104 struct eap_sm *sm, struct eap_mschapv2_data *data, u8 id)
107 struct eap_mschapv2_hdr *ms;
108 char *name = "hostapd"; /* TODO: make this configurable */
111 if (!data->auth_challenge_from_tls &&
112 os_get_random(data->auth_challenge, CHALLENGE_LEN)) {
113 wpa_printf(MSG_ERROR, "EAP-MSCHAPV2: Failed to get random "
115 data->state = FAILURE;
119 ms_len = sizeof(*ms) + 1 + CHALLENGE_LEN + os_strlen(name);
120 req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, ms_len,
121 EAP_CODE_REQUEST, id);
123 wpa_printf(MSG_ERROR, "EAP-MSCHAPV2: Failed to allocate memory"
125 data->state = FAILURE;
129 ms = wpabuf_put(req, sizeof(*ms));
130 ms->op_code = MSCHAPV2_OP_CHALLENGE;
131 ms->mschapv2_id = id;
132 WPA_PUT_BE16(ms->ms_length, ms_len);
134 wpabuf_put_u8(req, CHALLENGE_LEN);
135 if (!data->auth_challenge_from_tls)
136 wpabuf_put_data(req, data->auth_challenge, CHALLENGE_LEN);
138 wpabuf_put(req, CHALLENGE_LEN);
139 wpa_hexdump(MSG_MSGDUMP, "EAP-MSCHAPV2: Challenge",
140 data->auth_challenge, CHALLENGE_LEN);
141 wpabuf_put_data(req, name, os_strlen(name));
147 static struct wpabuf * eap_mschapv2_build_success_req(
148 struct eap_sm *sm, struct eap_mschapv2_data *data, u8 id)
151 struct eap_mschapv2_hdr *ms;
153 char *message = "OK";
156 ms_len = sizeof(*ms) + 2 + 2 * sizeof(data->auth_response) + 1 + 2 +
158 req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, ms_len,
159 EAP_CODE_REQUEST, id);
161 wpa_printf(MSG_ERROR, "EAP-MSCHAPV2: Failed to allocate memory"
163 data->state = FAILURE;
167 ms = wpabuf_put(req, sizeof(*ms));
168 ms->op_code = MSCHAPV2_OP_SUCCESS;
169 ms->mschapv2_id = data->resp_mschapv2_id;
170 WPA_PUT_BE16(ms->ms_length, ms_len);
171 msg = (u8 *) (ms + 1);
173 wpabuf_put_u8(req, 'S');
174 wpabuf_put_u8(req, '=');
175 wpa_snprintf_hex_uppercase(
176 wpabuf_put(req, sizeof(data->auth_response) * 2),
177 sizeof(data->auth_response) * 2 + 1,
178 data->auth_response, sizeof(data->auth_response));
179 wpabuf_put_u8(req, ' ');
180 wpabuf_put_u8(req, 'M');
181 wpabuf_put_u8(req, '=');
182 wpabuf_put_data(req, message, os_strlen(message));
184 wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-MSCHAPV2: Success Request Message",
185 msg, ms_len - sizeof(*ms));
191 static struct wpabuf * eap_mschapv2_build_failure_req(
192 struct eap_sm *sm, struct eap_mschapv2_data *data, u8 id)
195 struct eap_mschapv2_hdr *ms;
196 char *message = "E=691 R=0 C=00000000000000000000000000000000 V=3 "
200 ms_len = sizeof(*ms) + os_strlen(message);
201 req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, ms_len,
202 EAP_CODE_REQUEST, id);
204 wpa_printf(MSG_ERROR, "EAP-MSCHAPV2: Failed to allocate memory"
206 data->state = FAILURE;
210 ms = wpabuf_put(req, sizeof(*ms));
211 ms->op_code = MSCHAPV2_OP_FAILURE;
212 ms->mschapv2_id = data->resp_mschapv2_id;
213 WPA_PUT_BE16(ms->ms_length, ms_len);
215 wpabuf_put_data(req, message, os_strlen(message));
217 wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-MSCHAPV2: Failure Request Message",
218 (u8 *) message, os_strlen(message));
224 static struct wpabuf * eap_mschapv2_buildReq(struct eap_sm *sm, void *priv,
227 struct eap_mschapv2_data *data = priv;
229 switch (data->state) {
231 return eap_mschapv2_build_challenge(sm, data, id);
233 return eap_mschapv2_build_success_req(sm, data, id);
235 return eap_mschapv2_build_failure_req(sm, data, id);
237 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Unknown state %d in "
238 "buildReq", data->state);
245 static Boolean eap_mschapv2_check(struct eap_sm *sm, void *priv,
246 struct wpabuf *respData)
248 struct eap_mschapv2_data *data = priv;
249 struct eap_mschapv2_hdr *resp;
253 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, respData,
255 if (pos == NULL || len < 1) {
256 wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Invalid frame");
260 resp = (struct eap_mschapv2_hdr *) pos;
261 if (data->state == CHALLENGE &&
262 resp->op_code != MSCHAPV2_OP_RESPONSE) {
263 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Expected Response - "
264 "ignore op %d", resp->op_code);
268 if (data->state == SUCCESS_REQ &&
269 resp->op_code != MSCHAPV2_OP_SUCCESS &&
270 resp->op_code != MSCHAPV2_OP_FAILURE) {
271 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Expected Success or "
272 "Failure - ignore op %d", resp->op_code);
276 if (data->state == FAILURE_REQ &&
277 resp->op_code != MSCHAPV2_OP_FAILURE) {
278 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Expected Failure "
279 "- ignore op %d", resp->op_code);
287 static void eap_mschapv2_process_response(struct eap_sm *sm,
288 struct eap_mschapv2_data *data,
289 struct wpabuf *respData)
291 struct eap_mschapv2_hdr *resp;
292 const u8 *pos, *end, *peer_challenge, *nt_response, *name;
294 size_t len, name_len, i;
296 const u8 *username, *user;
297 size_t username_len, user_len;
300 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, respData,
302 if (pos == NULL || len < 1)
303 return; /* Should not happen - frame already validated */
306 resp = (struct eap_mschapv2_hdr *) pos;
307 pos = (u8 *) (resp + 1);
309 if (len < sizeof(*resp) + 1 + 49 ||
310 resp->op_code != MSCHAPV2_OP_RESPONSE ||
312 wpa_hexdump_buf(MSG_DEBUG, "EAP-MSCHAPV2: Invalid response",
314 data->state = FAILURE;
317 data->resp_mschapv2_id = resp->mschapv2_id;
319 peer_challenge = pos;
325 name_len = end - name;
327 if (data->peer_challenge) {
328 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Using pre-configured "
330 peer_challenge = data->peer_challenge;
332 wpa_hexdump(MSG_MSGDUMP, "EAP-MSCHAPV2: Peer-Challenge",
334 wpa_hexdump(MSG_MSGDUMP, "EAP-MSCHAPV2: NT-Response", nt_response, 24);
335 wpa_printf(MSG_MSGDUMP, "EAP-MSCHAPV2: Flags 0x%x", flags);
336 wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-MSCHAPV2: Name", name, name_len);
338 /* MSCHAPv2 does not include optional domain name in the
339 * challenge-response calculation, so remove domain prefix
341 username = sm->identity;
342 username_len = sm->identity_len;
343 for (i = 0; i < username_len; i++) {
344 if (username[i] == '\\') {
345 username_len -= i + 1;
353 for (i = 0; i < user_len; i++) {
354 if (user[i] == '\\') {
361 if (username_len != user_len ||
362 os_memcmp(username, user, username_len) != 0) {
363 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Mismatch in user names");
364 wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: Expected user "
365 "name", username, username_len);
366 wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: Received user "
367 "name", user, user_len);
368 data->state = FAILURE;
372 wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-MSCHAPV2: User name",
373 username, username_len);
375 if (sm->user->password_hash) {
376 res = generate_nt_response_pwhash(data->auth_challenge,
378 username, username_len,
382 res = generate_nt_response(data->auth_challenge,
384 username, username_len,
386 sm->user->password_len,
390 data->state = FAILURE;
394 if (os_memcmp(nt_response, expected, 24) == 0) {
396 u8 pw_hash_buf[16], pw_hash_hash[16];
398 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Correct NT-Response");
399 data->state = SUCCESS_REQ;
401 /* Authenticator response is not really needed yet, but
402 * calculate it here so that peer_challenge and username need
404 if (sm->user->password_hash) {
405 pw_hash = sm->user->password;
407 nt_password_hash(sm->user->password,
408 sm->user->password_len,
410 pw_hash = pw_hash_buf;
412 generate_authenticator_response_pwhash(
413 pw_hash, peer_challenge, data->auth_challenge,
414 username, username_len, nt_response,
415 data->auth_response);
417 hash_nt_password_hash(pw_hash, pw_hash_hash);
418 get_master_key(pw_hash_hash, nt_response, data->master_key);
419 data->master_key_valid = 1;
420 wpa_hexdump_key(MSG_DEBUG, "EAP-MSCHAPV2: Derived Master Key",
421 data->master_key, MSCHAPV2_KEY_LEN);
423 wpa_hexdump(MSG_MSGDUMP, "EAP-MSCHAPV2: Expected NT-Response",
425 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Invalid NT-Response");
426 data->state = FAILURE_REQ;
431 static void eap_mschapv2_process_success_resp(struct eap_sm *sm,
432 struct eap_mschapv2_data *data,
433 struct wpabuf *respData)
435 struct eap_mschapv2_hdr *resp;
439 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, respData,
441 if (pos == NULL || len < 1)
442 return; /* Should not happen - frame already validated */
444 resp = (struct eap_mschapv2_hdr *) pos;
446 if (resp->op_code == MSCHAPV2_OP_SUCCESS) {
447 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Received Success Response"
448 " - authentication completed successfully");
449 data->state = SUCCESS;
451 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Did not receive Success "
452 "Response - peer rejected authentication");
453 data->state = FAILURE;
458 static void eap_mschapv2_process_failure_resp(struct eap_sm *sm,
459 struct eap_mschapv2_data *data,
460 struct wpabuf *respData)
462 struct eap_mschapv2_hdr *resp;
466 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, respData,
468 if (pos == NULL || len < 1)
469 return; /* Should not happen - frame already validated */
471 resp = (struct eap_mschapv2_hdr *) pos;
473 if (resp->op_code == MSCHAPV2_OP_FAILURE) {
474 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Received Failure Response"
475 " - authentication failed");
477 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Did not receive Failure "
478 "Response - authentication failed");
481 data->state = FAILURE;
485 static void eap_mschapv2_process(struct eap_sm *sm, void *priv,
486 struct wpabuf *respData)
488 struct eap_mschapv2_data *data = priv;
490 if (sm->user == NULL || sm->user->password == NULL) {
491 wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Password not configured");
492 data->state = FAILURE;
496 switch (data->state) {
498 eap_mschapv2_process_response(sm, data, respData);
501 eap_mschapv2_process_success_resp(sm, data, respData);
504 eap_mschapv2_process_failure_resp(sm, data, respData);
507 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Unknown state %d in "
508 "process", data->state);
514 static Boolean eap_mschapv2_isDone(struct eap_sm *sm, void *priv)
516 struct eap_mschapv2_data *data = priv;
517 return data->state == SUCCESS || data->state == FAILURE;
521 static u8 * eap_mschapv2_getKey(struct eap_sm *sm, void *priv, size_t *len)
523 struct eap_mschapv2_data *data = priv;
526 if (data->state != SUCCESS || !data->master_key_valid)
529 *len = 2 * MSCHAPV2_KEY_LEN;
530 key = os_malloc(*len);
533 /* MSK = server MS-MPPE-Recv-Key | MS-MPPE-Send-Key */
534 get_asymetric_start_key(data->master_key, key, MSCHAPV2_KEY_LEN, 0, 1);
535 get_asymetric_start_key(data->master_key, key + MSCHAPV2_KEY_LEN,
536 MSCHAPV2_KEY_LEN, 1, 1);
537 wpa_hexdump_key(MSG_DEBUG, "EAP-MSCHAPV2: Derived key", key, *len);
543 static Boolean eap_mschapv2_isSuccess(struct eap_sm *sm, void *priv)
545 struct eap_mschapv2_data *data = priv;
546 return data->state == SUCCESS;
550 int eap_server_mschapv2_register(void)
552 struct eap_method *eap;
555 eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
556 EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2,
561 eap->init = eap_mschapv2_init;
562 eap->reset = eap_mschapv2_reset;
563 eap->buildReq = eap_mschapv2_buildReq;
564 eap->check = eap_mschapv2_check;
565 eap->process = eap_mschapv2_process;
566 eap->isDone = eap_mschapv2_isDone;
567 eap->getKey = eap_mschapv2_getKey;
568 eap->isSuccess = eap_mschapv2_isSuccess;
570 ret = eap_server_method_register(eap);
572 eap_server_method_free(eap);