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.
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;
299
pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, respData,
301
if (pos == NULL || len < 1)
302
return; /* Should not happen - frame already validated */
305
resp = (struct eap_mschapv2_hdr *) pos;
306
pos = (u8 *) (resp + 1);
308
if (len < sizeof(*resp) + 1 + 49 ||
309
resp->op_code != MSCHAPV2_OP_RESPONSE ||
311
wpa_hexdump_buf(MSG_DEBUG, "EAP-MSCHAPV2: Invalid response",
313
data->state = FAILURE;
316
data->resp_mschapv2_id = resp->mschapv2_id;
318
peer_challenge = pos;
324
name_len = end - name;
326
if (data->peer_challenge) {
327
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Using pre-configured "
329
peer_challenge = data->peer_challenge;
331
wpa_hexdump(MSG_MSGDUMP, "EAP-MSCHAPV2: Peer-Challenge",
333
wpa_hexdump(MSG_MSGDUMP, "EAP-MSCHAPV2: NT-Response", nt_response, 24);
334
wpa_printf(MSG_MSGDUMP, "EAP-MSCHAPV2: Flags 0x%x", flags);
335
wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-MSCHAPV2: Name", name, name_len);
337
/* MSCHAPv2 does not include optional domain name in the
338
* challenge-response calculation, so remove domain prefix
340
username = sm->identity;
341
username_len = sm->identity_len;
342
for (i = 0; i < username_len; i++) {
343
if (username[i] == '\\') {
344
username_len -= i + 1;
352
for (i = 0; i < user_len; i++) {
353
if (user[i] == '\\') {
360
if (username_len != user_len ||
361
os_memcmp(username, user, username_len) != 0) {
362
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Mismatch in user names");
363
wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: Expected user "
364
"name", username, username_len);
365
wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: Received user "
366
"name", user, user_len);
367
data->state = FAILURE;
371
wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-MSCHAPV2: User name",
372
username, username_len);
374
if (sm->user->password_hash) {
375
generate_nt_response_pwhash(data->auth_challenge,
377
username, username_len,
381
generate_nt_response(data->auth_challenge, peer_challenge,
382
username, username_len,
384
sm->user->password_len,
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
nt_password_hash(sm->user->password,
402
sm->user->password_len,
404
pw_hash = pw_hash_buf;
406
generate_authenticator_response_pwhash(
407
pw_hash, peer_challenge, data->auth_challenge,
408
username, username_len, nt_response,
409
data->auth_response);
411
hash_nt_password_hash(pw_hash, pw_hash_hash);
412
get_master_key(pw_hash_hash, nt_response, data->master_key);
413
data->master_key_valid = 1;
414
wpa_hexdump_key(MSG_DEBUG, "EAP-MSCHAPV2: Derived Master Key",
415
data->master_key, MSCHAPV2_KEY_LEN);
417
wpa_hexdump(MSG_MSGDUMP, "EAP-MSCHAPV2: Expected NT-Response",
419
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Invalid NT-Response");
420
data->state = FAILURE_REQ;
425
static void eap_mschapv2_process_success_resp(struct eap_sm *sm,
426
struct eap_mschapv2_data *data,
427
struct wpabuf *respData)
429
struct eap_mschapv2_hdr *resp;
433
pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, respData,
435
if (pos == NULL || len < 1)
436
return; /* Should not happen - frame already validated */
438
resp = (struct eap_mschapv2_hdr *) pos;
440
if (resp->op_code == MSCHAPV2_OP_SUCCESS) {
441
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Received Success Response"
442
" - authentication completed successfully");
443
data->state = SUCCESS;
445
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Did not receive Success "
446
"Response - peer rejected authentication");
447
data->state = FAILURE;
452
static void eap_mschapv2_process_failure_resp(struct eap_sm *sm,
453
struct eap_mschapv2_data *data,
454
struct wpabuf *respData)
456
struct eap_mschapv2_hdr *resp;
460
pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, respData,
462
if (pos == NULL || len < 1)
463
return; /* Should not happen - frame already validated */
465
resp = (struct eap_mschapv2_hdr *) pos;
467
if (resp->op_code == MSCHAPV2_OP_FAILURE) {
468
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Received Failure Response"
469
" - authentication failed");
471
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Did not receive Failure "
472
"Response - authentication failed");
475
data->state = FAILURE;
479
static void eap_mschapv2_process(struct eap_sm *sm, void *priv,
480
struct wpabuf *respData)
482
struct eap_mschapv2_data *data = priv;
484
if (sm->user == NULL || sm->user->password == NULL) {
485
wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Password not configured");
486
data->state = FAILURE;
490
switch (data->state) {
492
eap_mschapv2_process_response(sm, data, respData);
495
eap_mschapv2_process_success_resp(sm, data, respData);
498
eap_mschapv2_process_failure_resp(sm, data, respData);
501
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Unknown state %d in "
502
"process", data->state);
508
static Boolean eap_mschapv2_isDone(struct eap_sm *sm, void *priv)
510
struct eap_mschapv2_data *data = priv;
511
return data->state == SUCCESS || data->state == FAILURE;
515
static u8 * eap_mschapv2_getKey(struct eap_sm *sm, void *priv, size_t *len)
517
struct eap_mschapv2_data *data = priv;
520
if (data->state != SUCCESS || !data->master_key_valid)
523
*len = 2 * MSCHAPV2_KEY_LEN;
524
key = os_malloc(*len);
527
/* MSK = server MS-MPPE-Recv-Key | MS-MPPE-Send-Key */
528
get_asymetric_start_key(data->master_key, key, MSCHAPV2_KEY_LEN, 0, 1);
529
get_asymetric_start_key(data->master_key, key + MSCHAPV2_KEY_LEN,
530
MSCHAPV2_KEY_LEN, 1, 1);
531
wpa_hexdump_key(MSG_DEBUG, "EAP-MSCHAPV2: Derived key", key, *len);
537
static Boolean eap_mschapv2_isSuccess(struct eap_sm *sm, void *priv)
539
struct eap_mschapv2_data *data = priv;
540
return data->state == SUCCESS;
544
int eap_server_mschapv2_register(void)
546
struct eap_method *eap;
549
eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
550
EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2,
555
eap->init = eap_mschapv2_init;
556
eap->reset = eap_mschapv2_reset;
557
eap->buildReq = eap_mschapv2_buildReq;
558
eap->check = eap_mschapv2_check;
559
eap->process = eap_mschapv2_process;
560
eap->isDone = eap_mschapv2_isDone;
561
eap->getKey = eap_mschapv2_getKey;
562
eap->isSuccess = eap_mschapv2_isSuccess;
564
ret = eap_server_method_register(eap);
566
eap_server_method_free(eap);