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;
105 if (!data->auth_challenge_from_tls &&
106 random_get_bytes(data->auth_challenge, CHALLENGE_LEN)) {
107 wpa_printf(MSG_ERROR, "EAP-MSCHAPV2: Failed to get random "
109 data->state = FAILURE;
113 ms_len = sizeof(*ms) + 1 + CHALLENGE_LEN + sm->server_id_len;
114 req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, ms_len,
115 EAP_CODE_REQUEST, id);
117 wpa_printf(MSG_ERROR, "EAP-MSCHAPV2: Failed to allocate memory"
119 data->state = FAILURE;
123 ms = wpabuf_put(req, sizeof(*ms));
124 ms->op_code = MSCHAPV2_OP_CHALLENGE;
125 ms->mschapv2_id = id;
126 WPA_PUT_BE16(ms->ms_length, ms_len);
128 wpabuf_put_u8(req, CHALLENGE_LEN);
129 if (!data->auth_challenge_from_tls)
130 wpabuf_put_data(req, data->auth_challenge, CHALLENGE_LEN);
132 wpabuf_put(req, CHALLENGE_LEN);
133 wpa_hexdump(MSG_MSGDUMP, "EAP-MSCHAPV2: Challenge",
134 data->auth_challenge, CHALLENGE_LEN);
135 wpabuf_put_data(req, sm->server_id, sm->server_id_len);
141 static struct wpabuf * eap_mschapv2_build_success_req(
142 struct eap_sm *sm, struct eap_mschapv2_data *data, u8 id)
145 struct eap_mschapv2_hdr *ms;
147 char *message = "OK";
150 ms_len = sizeof(*ms) + 2 + 2 * sizeof(data->auth_response) + 1 + 2 +
152 req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, ms_len,
153 EAP_CODE_REQUEST, id);
155 wpa_printf(MSG_ERROR, "EAP-MSCHAPV2: Failed to allocate memory"
157 data->state = FAILURE;
161 ms = wpabuf_put(req, sizeof(*ms));
162 ms->op_code = MSCHAPV2_OP_SUCCESS;
163 ms->mschapv2_id = data->resp_mschapv2_id;
164 WPA_PUT_BE16(ms->ms_length, ms_len);
165 msg = (u8 *) (ms + 1);
167 wpabuf_put_u8(req, 'S');
168 wpabuf_put_u8(req, '=');
169 wpa_snprintf_hex_uppercase(
170 wpabuf_put(req, sizeof(data->auth_response) * 2),
171 sizeof(data->auth_response) * 2 + 1,
172 data->auth_response, sizeof(data->auth_response));
173 wpabuf_put_u8(req, ' ');
174 wpabuf_put_u8(req, 'M');
175 wpabuf_put_u8(req, '=');
176 wpabuf_put_data(req, message, os_strlen(message));
178 wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-MSCHAPV2: Success Request Message",
179 msg, ms_len - sizeof(*ms));
185 static struct wpabuf * eap_mschapv2_build_failure_req(
186 struct eap_sm *sm, struct eap_mschapv2_data *data, u8 id)
189 struct eap_mschapv2_hdr *ms;
190 char *message = "E=691 R=0 C=00000000000000000000000000000000 V=3 "
194 ms_len = sizeof(*ms) + os_strlen(message);
195 req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, ms_len,
196 EAP_CODE_REQUEST, id);
198 wpa_printf(MSG_ERROR, "EAP-MSCHAPV2: Failed to allocate memory"
200 data->state = FAILURE;
204 ms = wpabuf_put(req, sizeof(*ms));
205 ms->op_code = MSCHAPV2_OP_FAILURE;
206 ms->mschapv2_id = data->resp_mschapv2_id;
207 WPA_PUT_BE16(ms->ms_length, ms_len);
209 wpabuf_put_data(req, message, os_strlen(message));
211 wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-MSCHAPV2: Failure Request Message",
212 (u8 *) message, os_strlen(message));
218 static struct wpabuf * eap_mschapv2_buildReq(struct eap_sm *sm, void *priv,
221 struct eap_mschapv2_data *data = priv;
223 switch (data->state) {
225 return eap_mschapv2_build_challenge(sm, data, id);
227 return eap_mschapv2_build_success_req(sm, data, id);
229 return eap_mschapv2_build_failure_req(sm, data, id);
231 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Unknown state %d in "
232 "buildReq", data->state);
239 static Boolean eap_mschapv2_check(struct eap_sm *sm, void *priv,
240 struct wpabuf *respData)
242 struct eap_mschapv2_data *data = priv;
243 struct eap_mschapv2_hdr *resp;
247 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, respData,
249 if (pos == NULL || len < 1) {
250 wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Invalid frame");
254 resp = (struct eap_mschapv2_hdr *) pos;
255 if (data->state == CHALLENGE &&
256 resp->op_code != MSCHAPV2_OP_RESPONSE) {
257 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Expected Response - "
258 "ignore op %d", resp->op_code);
262 if (data->state == SUCCESS_REQ &&
263 resp->op_code != MSCHAPV2_OP_SUCCESS &&
264 resp->op_code != MSCHAPV2_OP_FAILURE) {
265 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Expected Success or "
266 "Failure - ignore op %d", resp->op_code);
270 if (data->state == FAILURE_REQ &&
271 resp->op_code != MSCHAPV2_OP_FAILURE) {
272 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Expected Failure "
273 "- ignore op %d", resp->op_code);
281 static void eap_mschapv2_process_response(struct eap_sm *sm,
282 struct eap_mschapv2_data *data,
283 struct wpabuf *respData)
285 struct eap_mschapv2_hdr *resp;
286 const u8 *pos, *end, *peer_challenge, *nt_response, *name;
288 size_t len, name_len, i;
290 const u8 *username, *user;
291 size_t username_len, user_len;
294 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, respData,
296 if (pos == NULL || len < 1)
297 return; /* Should not happen - frame already validated */
300 resp = (struct eap_mschapv2_hdr *) pos;
301 pos = (u8 *) (resp + 1);
303 if (len < sizeof(*resp) + 1 + 49 ||
304 resp->op_code != MSCHAPV2_OP_RESPONSE ||
306 wpa_hexdump_buf(MSG_DEBUG, "EAP-MSCHAPV2: Invalid response",
308 data->state = FAILURE;
311 data->resp_mschapv2_id = resp->mschapv2_id;
313 peer_challenge = pos;
319 name_len = end - name;
321 if (data->peer_challenge) {
322 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Using pre-configured "
324 peer_challenge = data->peer_challenge;
326 wpa_hexdump(MSG_MSGDUMP, "EAP-MSCHAPV2: Peer-Challenge",
328 wpa_hexdump(MSG_MSGDUMP, "EAP-MSCHAPV2: NT-Response", nt_response, 24);
329 wpa_printf(MSG_MSGDUMP, "EAP-MSCHAPV2: Flags 0x%x", flags);
330 wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-MSCHAPV2: Name", name, name_len);
332 /* MSCHAPv2 does not include optional domain name in the
333 * challenge-response calculation, so remove domain prefix
335 username = sm->identity;
336 username_len = sm->identity_len;
337 for (i = 0; i < username_len; i++) {
338 if (username[i] == '\\') {
339 username_len -= i + 1;
347 for (i = 0; i < user_len; i++) {
348 if (user[i] == '\\') {
355 if (username_len != user_len ||
356 os_memcmp(username, user, username_len) != 0) {
357 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Mismatch in user names");
358 wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: Expected user "
359 "name", username, username_len);
360 wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: Received user "
361 "name", user, user_len);
362 data->state = FAILURE;
366 wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-MSCHAPV2: User name",
367 username, username_len);
369 if (sm->user->password_hash) {
370 res = generate_nt_response_pwhash(data->auth_challenge,
372 username, username_len,
376 res = generate_nt_response(data->auth_challenge,
378 username, username_len,
380 sm->user->password_len,
384 data->state = FAILURE;
388 if (os_memcmp(nt_response, expected, 24) == 0) {
390 u8 pw_hash_buf[16], pw_hash_hash[16];
392 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Correct NT-Response");
393 data->state = SUCCESS_REQ;
395 /* Authenticator response is not really needed yet, but
396 * calculate it here so that peer_challenge and username need
398 if (sm->user->password_hash) {
399 pw_hash = sm->user->password;
401 if (nt_password_hash(sm->user->password,
402 sm->user->password_len,
404 data->state = FAILURE;
407 pw_hash = pw_hash_buf;
409 generate_authenticator_response_pwhash(
410 pw_hash, peer_challenge, data->auth_challenge,
411 username, username_len, nt_response,
412 data->auth_response);
414 hash_nt_password_hash(pw_hash, pw_hash_hash);
415 get_master_key(pw_hash_hash, nt_response, data->master_key);
416 data->master_key_valid = 1;
417 wpa_hexdump_key(MSG_DEBUG, "EAP-MSCHAPV2: Derived Master Key",
418 data->master_key, MSCHAPV2_KEY_LEN);
420 wpa_hexdump(MSG_MSGDUMP, "EAP-MSCHAPV2: Expected NT-Response",
422 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Invalid NT-Response");
423 data->state = FAILURE_REQ;
428 static void eap_mschapv2_process_success_resp(struct eap_sm *sm,
429 struct eap_mschapv2_data *data,
430 struct wpabuf *respData)
432 struct eap_mschapv2_hdr *resp;
436 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, respData,
438 if (pos == NULL || len < 1)
439 return; /* Should not happen - frame already validated */
441 resp = (struct eap_mschapv2_hdr *) pos;
443 if (resp->op_code == MSCHAPV2_OP_SUCCESS) {
444 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Received Success Response"
445 " - authentication completed successfully");
446 data->state = SUCCESS;
448 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Did not receive Success "
449 "Response - peer rejected authentication");
450 data->state = FAILURE;
455 static void eap_mschapv2_process_failure_resp(struct eap_sm *sm,
456 struct eap_mschapv2_data *data,
457 struct wpabuf *respData)
459 struct eap_mschapv2_hdr *resp;
463 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, respData,
465 if (pos == NULL || len < 1)
466 return; /* Should not happen - frame already validated */
468 resp = (struct eap_mschapv2_hdr *) pos;
470 if (resp->op_code == MSCHAPV2_OP_FAILURE) {
471 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Received Failure Response"
472 " - authentication failed");
474 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Did not receive Failure "
475 "Response - authentication failed");
478 data->state = FAILURE;
482 static void eap_mschapv2_process(struct eap_sm *sm, void *priv,
483 struct wpabuf *respData)
485 struct eap_mschapv2_data *data = priv;
487 if (sm->user == NULL || sm->user->password == NULL) {
488 wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Password not configured");
489 data->state = FAILURE;
493 switch (data->state) {
495 eap_mschapv2_process_response(sm, data, respData);
498 eap_mschapv2_process_success_resp(sm, data, respData);
501 eap_mschapv2_process_failure_resp(sm, data, respData);
504 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Unknown state %d in "
505 "process", data->state);
511 static Boolean eap_mschapv2_isDone(struct eap_sm *sm, void *priv)
513 struct eap_mschapv2_data *data = priv;
514 return data->state == SUCCESS || data->state == FAILURE;
518 static u8 * eap_mschapv2_getKey(struct eap_sm *sm, void *priv, size_t *len)
520 struct eap_mschapv2_data *data = priv;
523 if (data->state != SUCCESS || !data->master_key_valid)
526 *len = 2 * MSCHAPV2_KEY_LEN;
527 key = os_malloc(*len);
530 /* MSK = server MS-MPPE-Recv-Key | MS-MPPE-Send-Key */
531 get_asymetric_start_key(data->master_key, key, MSCHAPV2_KEY_LEN, 0, 1);
532 get_asymetric_start_key(data->master_key, key + MSCHAPV2_KEY_LEN,
533 MSCHAPV2_KEY_LEN, 1, 1);
534 wpa_hexdump_key(MSG_DEBUG, "EAP-MSCHAPV2: Derived key", key, *len);
540 static Boolean eap_mschapv2_isSuccess(struct eap_sm *sm, void *priv)
542 struct eap_mschapv2_data *data = priv;
543 return data->state == SUCCESS;
547 int eap_server_mschapv2_register(void)
549 struct eap_method *eap;
552 eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
553 EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2,
558 eap->init = eap_mschapv2_init;
559 eap->reset = eap_mschapv2_reset;
560 eap->buildReq = eap_mschapv2_buildReq;
561 eap->check = eap_mschapv2_check;
562 eap->process = eap_mschapv2_process;
563 eap->isDone = eap_mschapv2_isDone;
564 eap->getKey = eap_mschapv2_getKey;
565 eap->isSuccess = eap_mschapv2_isSuccess;
567 ret = eap_server_method_register(eap);
569 eap_server_method_free(eap);