2 * hostapd / EAP-MSCHAPv2 (draft-kamath-pppext-eap-mschapv2-00.txt) server
3 * Copyright (c) 2004-2007, 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/ms_funcs.h"
13 #include "crypto/random.h"
17 struct eap_mschapv2_hdr {
18 u8 op_code; /* MSCHAPV2_OP_* */
19 u8 mschapv2_id; /* must be changed for challenges, but not for
21 u8 ms_length[2]; /* Note: misaligned; length - 5 */
22 /* followed by data */
25 #define MSCHAPV2_OP_CHALLENGE 1
26 #define MSCHAPV2_OP_RESPONSE 2
27 #define MSCHAPV2_OP_SUCCESS 3
28 #define MSCHAPV2_OP_FAILURE 4
29 #define MSCHAPV2_OP_CHANGE_PASSWORD 7
31 #define MSCHAPV2_RESP_LEN 49
33 #define ERROR_RESTRICTED_LOGON_HOURS 646
34 #define ERROR_ACCT_DISABLED 647
35 #define ERROR_PASSWD_EXPIRED 648
36 #define ERROR_NO_DIALIN_PERMISSION 649
37 #define ERROR_AUTHENTICATION_FAILURE 691
38 #define ERROR_CHANGING_PASSWORD 709
40 #define PASSWD_CHANGE_CHAL_LEN 16
41 #define MSCHAPV2_KEY_LEN 16
44 #define CHALLENGE_LEN 16
46 struct eap_mschapv2_data {
47 u8 auth_challenge[CHALLENGE_LEN];
48 int auth_challenge_from_tls;
51 enum { CHALLENGE, SUCCESS_REQ, FAILURE_REQ, SUCCESS, FAILURE } state;
58 static void * eap_mschapv2_init(struct eap_sm *sm)
60 struct eap_mschapv2_data *data;
62 data = os_zalloc(sizeof(*data));
65 data->state = CHALLENGE;
67 if (sm->auth_challenge) {
68 os_memcpy(data->auth_challenge, sm->auth_challenge,
70 data->auth_challenge_from_tls = 1;
73 if (sm->peer_challenge) {
74 data->peer_challenge = os_malloc(CHALLENGE_LEN);
75 if (data->peer_challenge == NULL) {
79 os_memcpy(data->peer_challenge, sm->peer_challenge,
87 static void eap_mschapv2_reset(struct eap_sm *sm, void *priv)
89 struct eap_mschapv2_data *data = priv;
93 os_free(data->peer_challenge);
98 static struct wpabuf * eap_mschapv2_build_challenge(
99 struct eap_sm *sm, struct eap_mschapv2_data *data, u8 id)
102 struct eap_mschapv2_hdr *ms;
103 char *name = "hostapd"; /* TODO: make this configurable */
106 if (!data->auth_challenge_from_tls &&
107 random_get_bytes(data->auth_challenge, CHALLENGE_LEN)) {
108 wpa_printf(MSG_ERROR, "EAP-MSCHAPV2: Failed to get random "
110 data->state = FAILURE;
114 ms_len = sizeof(*ms) + 1 + CHALLENGE_LEN + os_strlen(name);
115 req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, ms_len,
116 EAP_CODE_REQUEST, id);
118 wpa_printf(MSG_ERROR, "EAP-MSCHAPV2: Failed to allocate memory"
120 data->state = FAILURE;
124 ms = wpabuf_put(req, sizeof(*ms));
125 ms->op_code = MSCHAPV2_OP_CHALLENGE;
126 ms->mschapv2_id = id;
127 WPA_PUT_BE16(ms->ms_length, ms_len);
129 wpabuf_put_u8(req, CHALLENGE_LEN);
130 if (!data->auth_challenge_from_tls)
131 wpabuf_put_data(req, data->auth_challenge, CHALLENGE_LEN);
133 wpabuf_put(req, CHALLENGE_LEN);
134 wpa_hexdump(MSG_MSGDUMP, "EAP-MSCHAPV2: Challenge",
135 data->auth_challenge, CHALLENGE_LEN);
136 wpabuf_put_data(req, name, os_strlen(name));
142 static struct wpabuf * eap_mschapv2_build_success_req(
143 struct eap_sm *sm, struct eap_mschapv2_data *data, u8 id)
146 struct eap_mschapv2_hdr *ms;
148 char *message = "OK";
151 ms_len = sizeof(*ms) + 2 + 2 * sizeof(data->auth_response) + 1 + 2 +
153 req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, ms_len,
154 EAP_CODE_REQUEST, id);
156 wpa_printf(MSG_ERROR, "EAP-MSCHAPV2: Failed to allocate memory"
158 data->state = FAILURE;
162 ms = wpabuf_put(req, sizeof(*ms));
163 ms->op_code = MSCHAPV2_OP_SUCCESS;
164 ms->mschapv2_id = data->resp_mschapv2_id;
165 WPA_PUT_BE16(ms->ms_length, ms_len);
166 msg = (u8 *) (ms + 1);
168 wpabuf_put_u8(req, 'S');
169 wpabuf_put_u8(req, '=');
170 wpa_snprintf_hex_uppercase(
171 wpabuf_put(req, sizeof(data->auth_response) * 2),
172 sizeof(data->auth_response) * 2 + 1,
173 data->auth_response, sizeof(data->auth_response));
174 wpabuf_put_u8(req, ' ');
175 wpabuf_put_u8(req, 'M');
176 wpabuf_put_u8(req, '=');
177 wpabuf_put_data(req, message, os_strlen(message));
179 wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-MSCHAPV2: Success Request Message",
180 msg, ms_len - sizeof(*ms));
186 static struct wpabuf * eap_mschapv2_build_failure_req(
187 struct eap_sm *sm, struct eap_mschapv2_data *data, u8 id)
190 struct eap_mschapv2_hdr *ms;
191 char *message = "E=691 R=0 C=00000000000000000000000000000000 V=3 "
195 ms_len = sizeof(*ms) + os_strlen(message);
196 req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, ms_len,
197 EAP_CODE_REQUEST, id);
199 wpa_printf(MSG_ERROR, "EAP-MSCHAPV2: Failed to allocate memory"
201 data->state = FAILURE;
205 ms = wpabuf_put(req, sizeof(*ms));
206 ms->op_code = MSCHAPV2_OP_FAILURE;
207 ms->mschapv2_id = data->resp_mschapv2_id;
208 WPA_PUT_BE16(ms->ms_length, ms_len);
210 wpabuf_put_data(req, message, os_strlen(message));
212 wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-MSCHAPV2: Failure Request Message",
213 (u8 *) message, os_strlen(message));
219 static struct wpabuf * eap_mschapv2_buildReq(struct eap_sm *sm, void *priv,
222 struct eap_mschapv2_data *data = priv;
224 switch (data->state) {
226 return eap_mschapv2_build_challenge(sm, data, id);
228 return eap_mschapv2_build_success_req(sm, data, id);
230 return eap_mschapv2_build_failure_req(sm, data, id);
232 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Unknown state %d in "
233 "buildReq", data->state);
240 static Boolean eap_mschapv2_check(struct eap_sm *sm, void *priv,
241 struct wpabuf *respData)
243 struct eap_mschapv2_data *data = priv;
244 struct eap_mschapv2_hdr *resp;
248 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, respData,
250 if (pos == NULL || len < 1) {
251 wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Invalid frame");
255 resp = (struct eap_mschapv2_hdr *) pos;
256 if (data->state == CHALLENGE &&
257 resp->op_code != MSCHAPV2_OP_RESPONSE) {
258 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Expected Response - "
259 "ignore op %d", resp->op_code);
263 if (data->state == SUCCESS_REQ &&
264 resp->op_code != MSCHAPV2_OP_SUCCESS &&
265 resp->op_code != MSCHAPV2_OP_FAILURE) {
266 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Expected Success or "
267 "Failure - ignore op %d", resp->op_code);
271 if (data->state == FAILURE_REQ &&
272 resp->op_code != MSCHAPV2_OP_FAILURE) {
273 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Expected Failure "
274 "- ignore op %d", resp->op_code);
282 static void eap_mschapv2_process_response(struct eap_sm *sm,
283 struct eap_mschapv2_data *data,
284 struct wpabuf *respData)
286 struct eap_mschapv2_hdr *resp;
287 const u8 *pos, *end, *peer_challenge, *nt_response, *name;
289 size_t len, name_len, i;
291 const u8 *username, *user;
292 size_t username_len, user_len;
295 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, respData,
297 if (pos == NULL || len < 1)
298 return; /* Should not happen - frame already validated */
301 resp = (struct eap_mschapv2_hdr *) pos;
302 pos = (u8 *) (resp + 1);
304 if (len < sizeof(*resp) + 1 + 49 ||
305 resp->op_code != MSCHAPV2_OP_RESPONSE ||
307 wpa_hexdump_buf(MSG_DEBUG, "EAP-MSCHAPV2: Invalid response",
309 data->state = FAILURE;
312 data->resp_mschapv2_id = resp->mschapv2_id;
314 peer_challenge = pos;
320 name_len = end - name;
322 if (data->peer_challenge) {
323 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Using pre-configured "
325 peer_challenge = data->peer_challenge;
327 wpa_hexdump(MSG_MSGDUMP, "EAP-MSCHAPV2: Peer-Challenge",
329 wpa_hexdump(MSG_MSGDUMP, "EAP-MSCHAPV2: NT-Response", nt_response, 24);
330 wpa_printf(MSG_MSGDUMP, "EAP-MSCHAPV2: Flags 0x%x", flags);
331 wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-MSCHAPV2: Name", name, name_len);
333 /* MSCHAPv2 does not include optional domain name in the
334 * challenge-response calculation, so remove domain prefix
336 username = sm->identity;
337 username_len = sm->identity_len;
338 for (i = 0; i < username_len; i++) {
339 if (username[i] == '\\') {
340 username_len -= i + 1;
348 for (i = 0; i < user_len; i++) {
349 if (user[i] == '\\') {
356 if (username_len != user_len ||
357 os_memcmp(username, user, username_len) != 0) {
358 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Mismatch in user names");
359 wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: Expected user "
360 "name", username, username_len);
361 wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: Received user "
362 "name", user, user_len);
363 data->state = FAILURE;
367 wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-MSCHAPV2: User name",
368 username, username_len);
370 if (sm->user->password_hash) {
371 res = generate_nt_response_pwhash(data->auth_challenge,
373 username, username_len,
377 res = generate_nt_response(data->auth_challenge,
379 username, username_len,
381 sm->user->password_len,
385 data->state = FAILURE;
389 if (os_memcmp(nt_response, expected, 24) == 0) {
391 u8 pw_hash_buf[16], pw_hash_hash[16];
393 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Correct NT-Response");
394 data->state = SUCCESS_REQ;
396 /* Authenticator response is not really needed yet, but
397 * calculate it here so that peer_challenge and username need
399 if (sm->user->password_hash) {
400 pw_hash = sm->user->password;
402 if (nt_password_hash(sm->user->password,
403 sm->user->password_len,
405 data->state = FAILURE;
408 pw_hash = pw_hash_buf;
410 generate_authenticator_response_pwhash(
411 pw_hash, peer_challenge, data->auth_challenge,
412 username, username_len, nt_response,
413 data->auth_response);
415 hash_nt_password_hash(pw_hash, pw_hash_hash);
416 get_master_key(pw_hash_hash, nt_response, data->master_key);
417 data->master_key_valid = 1;
418 wpa_hexdump_key(MSG_DEBUG, "EAP-MSCHAPV2: Derived Master Key",
419 data->master_key, MSCHAPV2_KEY_LEN);
421 wpa_hexdump(MSG_MSGDUMP, "EAP-MSCHAPV2: Expected NT-Response",
423 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Invalid NT-Response");
424 data->state = FAILURE_REQ;
429 static void eap_mschapv2_process_success_resp(struct eap_sm *sm,
430 struct eap_mschapv2_data *data,
431 struct wpabuf *respData)
433 struct eap_mschapv2_hdr *resp;
437 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, respData,
439 if (pos == NULL || len < 1)
440 return; /* Should not happen - frame already validated */
442 resp = (struct eap_mschapv2_hdr *) pos;
444 if (resp->op_code == MSCHAPV2_OP_SUCCESS) {
445 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Received Success Response"
446 " - authentication completed successfully");
447 data->state = SUCCESS;
449 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Did not receive Success "
450 "Response - peer rejected authentication");
451 data->state = FAILURE;
456 static void eap_mschapv2_process_failure_resp(struct eap_sm *sm,
457 struct eap_mschapv2_data *data,
458 struct wpabuf *respData)
460 struct eap_mschapv2_hdr *resp;
464 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, respData,
466 if (pos == NULL || len < 1)
467 return; /* Should not happen - frame already validated */
469 resp = (struct eap_mschapv2_hdr *) pos;
471 if (resp->op_code == MSCHAPV2_OP_FAILURE) {
472 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Received Failure Response"
473 " - authentication failed");
475 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Did not receive Failure "
476 "Response - authentication failed");
479 data->state = FAILURE;
483 static void eap_mschapv2_process(struct eap_sm *sm, void *priv,
484 struct wpabuf *respData)
486 struct eap_mschapv2_data *data = priv;
488 if (sm->user == NULL || sm->user->password == NULL) {
489 wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Password not configured");
490 data->state = FAILURE;
494 switch (data->state) {
496 eap_mschapv2_process_response(sm, data, respData);
499 eap_mschapv2_process_success_resp(sm, data, respData);
502 eap_mschapv2_process_failure_resp(sm, data, respData);
505 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Unknown state %d in "
506 "process", data->state);
512 static Boolean eap_mschapv2_isDone(struct eap_sm *sm, void *priv)
514 struct eap_mschapv2_data *data = priv;
515 return data->state == SUCCESS || data->state == FAILURE;
519 static u8 * eap_mschapv2_getKey(struct eap_sm *sm, void *priv, size_t *len)
521 struct eap_mschapv2_data *data = priv;
524 if (data->state != SUCCESS || !data->master_key_valid)
527 *len = 2 * MSCHAPV2_KEY_LEN;
528 key = os_malloc(*len);
531 /* MSK = server MS-MPPE-Recv-Key | MS-MPPE-Send-Key */
532 get_asymetric_start_key(data->master_key, key, MSCHAPV2_KEY_LEN, 0, 1);
533 get_asymetric_start_key(data->master_key, key + MSCHAPV2_KEY_LEN,
534 MSCHAPV2_KEY_LEN, 1, 1);
535 wpa_hexdump_key(MSG_DEBUG, "EAP-MSCHAPV2: Derived key", key, *len);
541 static Boolean eap_mschapv2_isSuccess(struct eap_sm *sm, void *priv)
543 struct eap_mschapv2_data *data = priv;
544 return data->state == SUCCESS;
548 int eap_server_mschapv2_register(void)
550 struct eap_method *eap;
553 eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
554 EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2,
559 eap->init = eap_mschapv2_init;
560 eap->reset = eap_mschapv2_reset;
561 eap->buildReq = eap_mschapv2_buildReq;
562 eap->check = eap_mschapv2_check;
563 eap->process = eap_mschapv2_process;
564 eap->isDone = eap_mschapv2_isDone;
565 eap->getKey = eap_mschapv2_getKey;
566 eap->isSuccess = eap_mschapv2_isSuccess;
568 ret = eap_server_method_register(eap);
570 eap_server_method_free(eap);