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);
94 bin_clear_free(data, sizeof(*data));
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;
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 buf = os_malloc(name_len * 4 + 1);
335 printf_encode(buf, name_len * 4 + 1, name, name_len);
336 eap_log_msg(sm, "EAP-MSCHAPV2 Name '%s'", buf);
340 /* MSCHAPv2 does not include optional domain name in the
341 * challenge-response calculation, so remove domain prefix
343 username = sm->identity;
344 username_len = sm->identity_len;
345 for (i = 0; i < username_len; i++) {
346 if (username[i] == '\\') {
347 username_len -= i + 1;
355 for (i = 0; i < user_len; i++) {
356 if (user[i] == '\\') {
363 if (username_len != user_len ||
364 os_memcmp(username, user, username_len) != 0) {
365 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Mismatch in user names");
366 wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: Expected user "
367 "name", username, username_len);
368 wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: Received user "
369 "name", user, user_len);
370 data->state = FAILURE;
374 wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-MSCHAPV2: User name",
375 username, username_len);
377 if (sm->user->password_hash) {
378 res = generate_nt_response_pwhash(data->auth_challenge,
380 username, username_len,
384 res = generate_nt_response(data->auth_challenge,
386 username, username_len,
388 sm->user->password_len,
392 data->state = FAILURE;
396 if (os_memcmp_const(nt_response, expected, 24) == 0) {
398 u8 pw_hash_buf[16], pw_hash_hash[16];
400 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Correct NT-Response");
401 data->state = SUCCESS_REQ;
403 /* Authenticator response is not really needed yet, but
404 * calculate it here so that peer_challenge and username need
406 if (sm->user->password_hash) {
407 pw_hash = sm->user->password;
409 if (nt_password_hash(sm->user->password,
410 sm->user->password_len,
412 data->state = FAILURE;
415 pw_hash = pw_hash_buf;
417 if (generate_authenticator_response_pwhash(
418 pw_hash, peer_challenge, data->auth_challenge,
419 username, username_len, nt_response,
420 data->auth_response) < 0 ||
421 hash_nt_password_hash(pw_hash, pw_hash_hash) < 0 ||
422 get_master_key(pw_hash_hash, nt_response,
424 data->state = FAILURE;
427 data->master_key_valid = 1;
428 wpa_hexdump_key(MSG_DEBUG, "EAP-MSCHAPV2: Derived Master Key",
429 data->master_key, MSCHAPV2_KEY_LEN);
431 wpa_hexdump(MSG_MSGDUMP, "EAP-MSCHAPV2: Expected NT-Response",
433 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Invalid NT-Response");
434 data->state = FAILURE_REQ;
439 static void eap_mschapv2_process_success_resp(struct eap_sm *sm,
440 struct eap_mschapv2_data *data,
441 struct wpabuf *respData)
443 struct eap_mschapv2_hdr *resp;
447 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, respData,
449 if (pos == NULL || len < 1)
450 return; /* Should not happen - frame already validated */
452 resp = (struct eap_mschapv2_hdr *) pos;
454 if (resp->op_code == MSCHAPV2_OP_SUCCESS) {
455 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Received Success Response"
456 " - authentication completed successfully");
457 data->state = SUCCESS;
459 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Did not receive Success "
460 "Response - peer rejected authentication");
461 data->state = FAILURE;
466 static void eap_mschapv2_process_failure_resp(struct eap_sm *sm,
467 struct eap_mschapv2_data *data,
468 struct wpabuf *respData)
470 struct eap_mschapv2_hdr *resp;
474 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, respData,
476 if (pos == NULL || len < 1)
477 return; /* Should not happen - frame already validated */
479 resp = (struct eap_mschapv2_hdr *) pos;
481 if (resp->op_code == MSCHAPV2_OP_FAILURE) {
482 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Received Failure Response"
483 " - authentication failed");
485 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Did not receive Failure "
486 "Response - authentication failed");
489 data->state = FAILURE;
493 static void eap_mschapv2_process(struct eap_sm *sm, void *priv,
494 struct wpabuf *respData)
496 struct eap_mschapv2_data *data = priv;
498 if (sm->user == NULL || sm->user->password == NULL) {
499 wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Password not configured");
500 data->state = FAILURE;
504 switch (data->state) {
506 eap_mschapv2_process_response(sm, data, respData);
509 eap_mschapv2_process_success_resp(sm, data, respData);
512 eap_mschapv2_process_failure_resp(sm, data, respData);
515 wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Unknown state %d in "
516 "process", data->state);
522 static Boolean eap_mschapv2_isDone(struct eap_sm *sm, void *priv)
524 struct eap_mschapv2_data *data = priv;
525 return data->state == SUCCESS || data->state == FAILURE;
529 static u8 * eap_mschapv2_getKey(struct eap_sm *sm, void *priv, size_t *len)
531 struct eap_mschapv2_data *data = priv;
534 if (data->state != SUCCESS || !data->master_key_valid)
537 *len = 2 * MSCHAPV2_KEY_LEN;
538 key = os_malloc(*len);
541 /* MSK = server MS-MPPE-Recv-Key | MS-MPPE-Send-Key */
542 get_asymetric_start_key(data->master_key, key, MSCHAPV2_KEY_LEN, 0, 1);
543 get_asymetric_start_key(data->master_key, key + MSCHAPV2_KEY_LEN,
544 MSCHAPV2_KEY_LEN, 1, 1);
545 wpa_hexdump_key(MSG_DEBUG, "EAP-MSCHAPV2: Derived key", key, *len);
551 static Boolean eap_mschapv2_isSuccess(struct eap_sm *sm, void *priv)
553 struct eap_mschapv2_data *data = priv;
554 return data->state == SUCCESS;
558 int eap_server_mschapv2_register(void)
560 struct eap_method *eap;
563 eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
564 EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2,
569 eap->init = eap_mschapv2_init;
570 eap->reset = eap_mschapv2_reset;
571 eap->buildReq = eap_mschapv2_buildReq;
572 eap->check = eap_mschapv2_check;
573 eap->process = eap_mschapv2_process;
574 eap->isDone = eap_mschapv2_isDone;
575 eap->getKey = eap_mschapv2_getKey;
576 eap->isSuccess = eap_mschapv2_isSuccess;
578 ret = eap_server_method_register(eap);
580 eap_server_method_free(eap);