Line data Source code
1 : /*
2 : * EAP peer method: EAP-MSCHAPV2 (draft-kamath-pppext-eap-mschapv2-00.txt)
3 : * Copyright (c) 2004-2008, Jouni Malinen <j@w1.fi>
4 : *
5 : * This software may be distributed under the terms of the BSD license.
6 : * See README for more details.
7 : *
8 : * This file implements EAP peer part of EAP-MSCHAPV2 method (EAP type 26).
9 : * draft-kamath-pppext-eap-mschapv2-00.txt defines the Microsoft EAP CHAP
10 : * Extensions Protocol, Version 2, for mutual authentication and key
11 : * derivation. This encapsulates MS-CHAP-v2 protocol which is defined in
12 : * RFC 2759. Use of EAP-MSCHAPV2 derived keys with MPPE cipher is described in
13 : * RFC 3079.
14 : */
15 :
16 : #include "includes.h"
17 :
18 : #include "common.h"
19 : #include "crypto/ms_funcs.h"
20 : #include "crypto/random.h"
21 : #include "common/wpa_ctrl.h"
22 : #include "mschapv2.h"
23 : #include "eap_i.h"
24 : #include "eap_config.h"
25 :
26 :
27 : #ifdef _MSC_VER
28 : #pragma pack(push, 1)
29 : #endif /* _MSC_VER */
30 :
31 : struct eap_mschapv2_hdr {
32 : u8 op_code; /* MSCHAPV2_OP_* */
33 : u8 mschapv2_id; /* usually same as EAP identifier; must be changed
34 : * for challenges, but not for success/failure */
35 : u8 ms_length[2]; /* Note: misaligned; length - 5 */
36 : /* followed by data */
37 : } STRUCT_PACKED;
38 :
39 : /* Response Data field */
40 : struct ms_response {
41 : u8 peer_challenge[MSCHAPV2_CHAL_LEN];
42 : u8 reserved[8];
43 : u8 nt_response[MSCHAPV2_NT_RESPONSE_LEN];
44 : u8 flags;
45 : } STRUCT_PACKED;
46 :
47 : /* Change-Password Data field */
48 : struct ms_change_password {
49 : u8 encr_password[516];
50 : u8 encr_hash[16];
51 : u8 peer_challenge[MSCHAPV2_CHAL_LEN];
52 : u8 reserved[8];
53 : u8 nt_response[MSCHAPV2_NT_RESPONSE_LEN];
54 : u8 flags[2];
55 : } STRUCT_PACKED;
56 :
57 : #ifdef _MSC_VER
58 : #pragma pack(pop)
59 : #endif /* _MSC_VER */
60 :
61 : #define MSCHAPV2_OP_CHALLENGE 1
62 : #define MSCHAPV2_OP_RESPONSE 2
63 : #define MSCHAPV2_OP_SUCCESS 3
64 : #define MSCHAPV2_OP_FAILURE 4
65 : #define MSCHAPV2_OP_CHANGE_PASSWORD 7
66 :
67 : #define ERROR_RESTRICTED_LOGON_HOURS 646
68 : #define ERROR_ACCT_DISABLED 647
69 : #define ERROR_PASSWD_EXPIRED 648
70 : #define ERROR_NO_DIALIN_PERMISSION 649
71 : #define ERROR_AUTHENTICATION_FAILURE 691
72 : #define ERROR_CHANGING_PASSWORD 709
73 :
74 : #define PASSWD_CHANGE_CHAL_LEN 16
75 : #define MSCHAPV2_KEY_LEN 16
76 :
77 :
78 : struct eap_mschapv2_data {
79 : u8 auth_response[MSCHAPV2_AUTH_RESPONSE_LEN];
80 : int auth_response_valid;
81 :
82 : int prev_error;
83 : u8 passwd_change_challenge[PASSWD_CHANGE_CHAL_LEN];
84 : int passwd_change_challenge_valid;
85 : int passwd_change_version;
86 :
87 : /* Optional challenge values generated in EAP-FAST Phase 1 negotiation
88 : */
89 : u8 *peer_challenge;
90 : u8 *auth_challenge;
91 :
92 : int phase2;
93 : u8 master_key[MSCHAPV2_MASTER_KEY_LEN];
94 : int master_key_valid;
95 : int success;
96 :
97 : struct wpabuf *prev_challenge;
98 : };
99 :
100 :
101 : static void eap_mschapv2_deinit(struct eap_sm *sm, void *priv);
102 :
103 :
104 49 : static void * eap_mschapv2_init(struct eap_sm *sm)
105 : {
106 : struct eap_mschapv2_data *data;
107 49 : data = os_zalloc(sizeof(*data));
108 49 : if (data == NULL)
109 0 : return NULL;
110 :
111 49 : if (sm->peer_challenge) {
112 4 : data->peer_challenge = os_malloc(MSCHAPV2_CHAL_LEN);
113 4 : if (data->peer_challenge == NULL) {
114 0 : eap_mschapv2_deinit(sm, data);
115 0 : return NULL;
116 : }
117 4 : os_memcpy(data->peer_challenge, sm->peer_challenge,
118 : MSCHAPV2_CHAL_LEN);
119 : }
120 :
121 49 : if (sm->auth_challenge) {
122 4 : data->auth_challenge = os_malloc(MSCHAPV2_CHAL_LEN);
123 4 : if (data->auth_challenge == NULL) {
124 0 : eap_mschapv2_deinit(sm, data);
125 0 : return NULL;
126 : }
127 4 : os_memcpy(data->auth_challenge, sm->auth_challenge,
128 : MSCHAPV2_CHAL_LEN);
129 : }
130 :
131 49 : data->phase2 = sm->init_phase2;
132 :
133 49 : return data;
134 : }
135 :
136 :
137 49 : static void eap_mschapv2_deinit(struct eap_sm *sm, void *priv)
138 : {
139 49 : struct eap_mschapv2_data *data = priv;
140 49 : os_free(data->peer_challenge);
141 49 : os_free(data->auth_challenge);
142 49 : wpabuf_free(data->prev_challenge);
143 49 : bin_clear_free(data, sizeof(*data));
144 49 : }
145 :
146 :
147 53 : static struct wpabuf * eap_mschapv2_challenge_reply(
148 : struct eap_sm *sm, struct eap_mschapv2_data *data, u8 id,
149 : u8 mschapv2_id, const u8 *auth_challenge)
150 : {
151 : struct wpabuf *resp;
152 : struct eap_mschapv2_hdr *ms;
153 : u8 *peer_challenge;
154 : int ms_len;
155 : struct ms_response *r;
156 : size_t identity_len, password_len;
157 : const u8 *identity, *password;
158 : int pwhash;
159 :
160 53 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Generating Challenge Response");
161 :
162 53 : identity = eap_get_config_identity(sm, &identity_len);
163 53 : password = eap_get_config_password2(sm, &password_len, &pwhash);
164 53 : if (identity == NULL || password == NULL)
165 0 : return NULL;
166 :
167 53 : ms_len = sizeof(*ms) + 1 + sizeof(*r) + identity_len;
168 53 : resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, ms_len,
169 : EAP_CODE_RESPONSE, id);
170 53 : if (resp == NULL)
171 0 : return NULL;
172 :
173 53 : ms = wpabuf_put(resp, sizeof(*ms));
174 53 : ms->op_code = MSCHAPV2_OP_RESPONSE;
175 53 : ms->mschapv2_id = mschapv2_id;
176 53 : if (data->prev_error) {
177 : /*
178 : * TODO: this does not seem to be enough when processing two
179 : * or more failure messages. IAS did not increment mschapv2_id
180 : * in its own packets, but it seemed to expect the peer to
181 : * increment this for all packets(?).
182 : */
183 0 : ms->mschapv2_id++;
184 : }
185 53 : WPA_PUT_BE16(ms->ms_length, ms_len);
186 :
187 53 : wpabuf_put_u8(resp, sizeof(*r)); /* Value-Size */
188 :
189 : /* Response */
190 53 : r = wpabuf_put(resp, sizeof(*r));
191 53 : peer_challenge = r->peer_challenge;
192 53 : if (data->peer_challenge) {
193 4 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: peer_challenge generated "
194 : "in Phase 1");
195 4 : peer_challenge = data->peer_challenge;
196 4 : os_memset(r->peer_challenge, 0, MSCHAPV2_CHAL_LEN);
197 49 : } else if (random_get_bytes(peer_challenge, MSCHAPV2_CHAL_LEN)) {
198 0 : wpabuf_free(resp);
199 0 : return NULL;
200 : }
201 53 : os_memset(r->reserved, 0, 8);
202 53 : if (data->auth_challenge) {
203 4 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: auth_challenge generated "
204 : "in Phase 1");
205 4 : auth_challenge = data->auth_challenge;
206 : }
207 53 : if (mschapv2_derive_response(identity, identity_len, password,
208 : password_len, pwhash, auth_challenge,
209 53 : peer_challenge, r->nt_response,
210 53 : data->auth_response, data->master_key)) {
211 0 : wpa_printf(MSG_ERROR, "EAP-MSCHAPV2: Failed to derive "
212 : "response");
213 0 : wpabuf_free(resp);
214 0 : return NULL;
215 : }
216 53 : data->auth_response_valid = 1;
217 53 : data->master_key_valid = 1;
218 :
219 53 : r->flags = 0; /* reserved, must be zero */
220 :
221 53 : wpabuf_put_data(resp, identity, identity_len);
222 53 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: TX identifier %d mschapv2_id %d "
223 53 : "(response)", id, ms->mschapv2_id);
224 53 : return resp;
225 : }
226 :
227 :
228 : /**
229 : * eap_mschapv2_process - Process an EAP-MSCHAPv2 challenge message
230 : * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
231 : * @data: Pointer to private EAP method data from eap_mschapv2_init()
232 : * @ret: Return values from EAP request validation and processing
233 : * @req: Pointer to EAP-MSCHAPv2 header from the request
234 : * @req_len: Length of the EAP-MSCHAPv2 data
235 : * @id: EAP identifier used in the request
236 : * Returns: Pointer to allocated EAP response packet (eapRespData) or %NULL if
237 : * no reply available
238 : */
239 53 : static struct wpabuf * eap_mschapv2_challenge(
240 : struct eap_sm *sm, struct eap_mschapv2_data *data,
241 : struct eap_method_ret *ret, const struct eap_mschapv2_hdr *req,
242 : size_t req_len, u8 id)
243 : {
244 : size_t len, challenge_len;
245 : const u8 *pos, *challenge;
246 :
247 106 : if (eap_get_config_identity(sm, &len) == NULL ||
248 53 : eap_get_config_password(sm, &len) == NULL)
249 0 : return NULL;
250 :
251 53 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Received challenge");
252 53 : if (req_len < sizeof(*req) + 1) {
253 0 : wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Too short challenge data "
254 : "(len %lu)", (unsigned long) req_len);
255 0 : ret->ignore = TRUE;
256 0 : return NULL;
257 : }
258 53 : pos = (const u8 *) (req + 1);
259 53 : challenge_len = *pos++;
260 53 : len = req_len - sizeof(*req) - 1;
261 53 : if (challenge_len != MSCHAPV2_CHAL_LEN) {
262 0 : wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Invalid challenge length "
263 : "%lu", (unsigned long) challenge_len);
264 0 : ret->ignore = TRUE;
265 0 : return NULL;
266 : }
267 :
268 53 : if (len < challenge_len) {
269 0 : wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Too short challenge"
270 : " packet: len=%lu challenge_len=%lu",
271 : (unsigned long) len, (unsigned long) challenge_len);
272 0 : ret->ignore = TRUE;
273 0 : return NULL;
274 : }
275 :
276 53 : if (data->passwd_change_challenge_valid) {
277 0 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Using challenge from the "
278 : "failure message");
279 0 : challenge = data->passwd_change_challenge;
280 : } else
281 53 : challenge = pos;
282 53 : pos += challenge_len;
283 53 : len -= challenge_len;
284 53 : wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: Authentication Servername",
285 : pos, len);
286 :
287 53 : ret->ignore = FALSE;
288 53 : ret->methodState = METHOD_MAY_CONT;
289 53 : ret->decision = DECISION_FAIL;
290 53 : ret->allowNotifications = TRUE;
291 :
292 53 : return eap_mschapv2_challenge_reply(sm, data, id, req->mschapv2_id,
293 : challenge);
294 : }
295 :
296 :
297 0 : static void eap_mschapv2_password_changed(struct eap_sm *sm,
298 : struct eap_mschapv2_data *data)
299 : {
300 0 : struct eap_peer_config *config = eap_get_config(sm);
301 0 : if (config && config->new_password) {
302 0 : wpa_msg(sm->msg_ctx, MSG_INFO,
303 : WPA_EVENT_PASSWORD_CHANGED
304 : "EAP-MSCHAPV2: Password changed successfully");
305 0 : data->prev_error = 0;
306 0 : bin_clear_free(config->password, config->password_len);
307 0 : if (config->flags & EAP_CONFIG_FLAGS_EXT_PASSWORD) {
308 : /* TODO: update external storage */
309 0 : } else if (config->flags & EAP_CONFIG_FLAGS_PASSWORD_NTHASH) {
310 0 : config->password = os_malloc(16);
311 0 : config->password_len = 16;
312 0 : if (config->password &&
313 0 : nt_password_hash(config->new_password,
314 : config->new_password_len,
315 : config->password)) {
316 0 : bin_clear_free(config->password,
317 : config->password_len);
318 0 : config->password = NULL;
319 0 : config->password_len = 0;
320 : }
321 0 : bin_clear_free(config->new_password,
322 : config->new_password_len);
323 : } else {
324 0 : config->password = config->new_password;
325 0 : config->password_len = config->new_password_len;
326 : }
327 0 : config->new_password = NULL;
328 0 : config->new_password_len = 0;
329 : }
330 0 : }
331 :
332 :
333 : /**
334 : * eap_mschapv2_process - Process an EAP-MSCHAPv2 success message
335 : * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
336 : * @data: Pointer to private EAP method data from eap_mschapv2_init()
337 : * @ret: Return values from EAP request validation and processing
338 : * @req: Pointer to EAP-MSCHAPv2 header from the request
339 : * @req_len: Length of the EAP-MSCHAPv2 data
340 : * @id: EAP identifier used in th erequest
341 : * Returns: Pointer to allocated EAP response packet (eapRespData) or %NULL if
342 : * no reply available
343 : */
344 47 : static struct wpabuf * eap_mschapv2_success(struct eap_sm *sm,
345 : struct eap_mschapv2_data *data,
346 : struct eap_method_ret *ret,
347 : const struct eap_mschapv2_hdr *req,
348 : size_t req_len, u8 id)
349 : {
350 : struct wpabuf *resp;
351 : const u8 *pos;
352 : size_t len;
353 :
354 47 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Received success");
355 47 : len = req_len - sizeof(*req);
356 47 : pos = (const u8 *) (req + 1);
357 94 : if (!data->auth_response_valid ||
358 47 : mschapv2_verify_auth_response(data->auth_response, pos, len)) {
359 0 : wpa_printf(MSG_WARNING, "EAP-MSCHAPV2: Invalid authenticator "
360 : "response in success request");
361 0 : ret->methodState = METHOD_DONE;
362 0 : ret->decision = DECISION_FAIL;
363 0 : return NULL;
364 : }
365 47 : pos += 2 + 2 * MSCHAPV2_AUTH_RESPONSE_LEN;
366 47 : len -= 2 + 2 * MSCHAPV2_AUTH_RESPONSE_LEN;
367 141 : while (len > 0 && *pos == ' ') {
368 47 : pos++;
369 47 : len--;
370 : }
371 47 : wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: Success message",
372 : pos, len);
373 47 : wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Authentication succeeded");
374 :
375 : /* Note: Only op_code of the EAP-MSCHAPV2 header is included in success
376 : * message. */
377 47 : resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, 1,
378 : EAP_CODE_RESPONSE, id);
379 47 : if (resp == NULL) {
380 0 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Failed to allocate "
381 : "buffer for success response");
382 0 : ret->ignore = TRUE;
383 0 : return NULL;
384 : }
385 :
386 47 : wpabuf_put_u8(resp, MSCHAPV2_OP_SUCCESS); /* op_code */
387 :
388 47 : ret->methodState = METHOD_DONE;
389 47 : ret->decision = DECISION_UNCOND_SUCC;
390 47 : ret->allowNotifications = FALSE;
391 47 : data->success = 1;
392 :
393 47 : if (data->prev_error == ERROR_PASSWD_EXPIRED)
394 0 : eap_mschapv2_password_changed(sm, data);
395 :
396 47 : return resp;
397 : }
398 :
399 :
400 3 : static int eap_mschapv2_failure_txt(struct eap_sm *sm,
401 : struct eap_mschapv2_data *data, char *txt)
402 : {
403 3 : char *pos, *msg = "";
404 3 : int retry = 1;
405 3 : struct eap_peer_config *config = eap_get_config(sm);
406 :
407 : /* For example:
408 : * E=691 R=1 C=<32 octets hex challenge> V=3 M=Authentication Failure
409 : */
410 :
411 3 : pos = txt;
412 :
413 3 : if (pos && os_strncmp(pos, "E=", 2) == 0) {
414 3 : pos += 2;
415 3 : data->prev_error = atoi(pos);
416 3 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: error %d",
417 : data->prev_error);
418 3 : pos = os_strchr(pos, ' ');
419 3 : if (pos)
420 3 : pos++;
421 : }
422 :
423 3 : if (pos && os_strncmp(pos, "R=", 2) == 0) {
424 3 : pos += 2;
425 3 : retry = atoi(pos);
426 3 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: retry is %sallowed",
427 : retry == 1 ? "" : "not ");
428 3 : pos = os_strchr(pos, ' ');
429 3 : if (pos)
430 3 : pos++;
431 : }
432 :
433 6 : if (pos && os_strncmp(pos, "C=", 2) == 0) {
434 : int hex_len;
435 3 : pos += 2;
436 3 : hex_len = os_strchr(pos, ' ') - (char *) pos;
437 3 : if (hex_len == PASSWD_CHANGE_CHAL_LEN * 2) {
438 3 : if (hexstr2bin(pos, data->passwd_change_challenge,
439 : PASSWD_CHANGE_CHAL_LEN)) {
440 0 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: invalid "
441 : "failure challenge");
442 : } else {
443 3 : wpa_hexdump(MSG_DEBUG, "EAP-MSCHAPV2: failure "
444 : "challenge",
445 3 : data->passwd_change_challenge,
446 : PASSWD_CHANGE_CHAL_LEN);
447 3 : data->passwd_change_challenge_valid = 1;
448 : }
449 : } else {
450 0 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: invalid failure "
451 : "challenge len %d", hex_len);
452 : }
453 3 : pos = os_strchr(pos, ' ');
454 3 : if (pos)
455 3 : pos++;
456 : } else {
457 0 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: required challenge field "
458 : "was not present in failure message");
459 : }
460 :
461 3 : if (pos && os_strncmp(pos, "V=", 2) == 0) {
462 3 : pos += 2;
463 3 : data->passwd_change_version = atoi(pos);
464 3 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: password changing "
465 : "protocol version %d", data->passwd_change_version);
466 3 : pos = os_strchr(pos, ' ');
467 3 : if (pos)
468 3 : pos++;
469 : }
470 :
471 3 : if (pos && os_strncmp(pos, "M=", 2) == 0) {
472 3 : pos += 2;
473 3 : msg = pos;
474 : }
475 3 : if (data->prev_error == ERROR_AUTHENTICATION_FAILURE && retry &&
476 0 : config && config->phase2 &&
477 0 : os_strstr(config->phase2, "mschapv2_retry=0")) {
478 0 : wpa_printf(MSG_DEBUG,
479 : "EAP-MSCHAPV2: mark password retry disabled based on local configuration");
480 0 : retry = 0;
481 : }
482 3 : wpa_msg(sm->msg_ctx, MSG_WARNING,
483 : "EAP-MSCHAPV2: failure message: '%s' (retry %sallowed, error "
484 : "%d)",
485 : msg, retry == 1 ? "" : "not ", data->prev_error);
486 3 : if (data->prev_error == ERROR_PASSWD_EXPIRED &&
487 0 : data->passwd_change_version == 3 && config) {
488 0 : if (config->new_password == NULL) {
489 0 : wpa_msg(sm->msg_ctx, MSG_INFO,
490 : "EAP-MSCHAPV2: Password expired - password "
491 : "change required");
492 0 : eap_sm_request_new_password(sm);
493 : }
494 3 : } else if (retry == 1 && config) {
495 : /* TODO: could prevent the current password from being used
496 : * again at least for some period of time */
497 0 : if (!config->mschapv2_retry)
498 0 : eap_sm_request_identity(sm);
499 0 : eap_sm_request_password(sm);
500 0 : config->mschapv2_retry = 1;
501 3 : } else if (config) {
502 : /* TODO: prevent retries using same username/password */
503 3 : config->mschapv2_retry = 0;
504 : }
505 :
506 3 : return retry == 1;
507 : }
508 :
509 :
510 0 : static struct wpabuf * eap_mschapv2_change_password(
511 : struct eap_sm *sm, struct eap_mschapv2_data *data,
512 : struct eap_method_ret *ret, const struct eap_mschapv2_hdr *req, u8 id)
513 : {
514 : struct wpabuf *resp;
515 : int ms_len;
516 : const u8 *username, *password, *new_password;
517 : size_t username_len, password_len, new_password_len;
518 : struct eap_mschapv2_hdr *ms;
519 : struct ms_change_password *cp;
520 : u8 password_hash[16], password_hash_hash[16];
521 : int pwhash;
522 :
523 0 : username = eap_get_config_identity(sm, &username_len);
524 0 : password = eap_get_config_password2(sm, &password_len, &pwhash);
525 0 : new_password = eap_get_config_new_password(sm, &new_password_len);
526 0 : if (username == NULL || password == NULL || new_password == NULL)
527 0 : return NULL;
528 :
529 0 : username = mschapv2_remove_domain(username, &username_len);
530 :
531 0 : ret->ignore = FALSE;
532 0 : ret->methodState = METHOD_MAY_CONT;
533 0 : ret->decision = DECISION_COND_SUCC;
534 0 : ret->allowNotifications = TRUE;
535 :
536 0 : ms_len = sizeof(*ms) + sizeof(*cp);
537 0 : resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, ms_len,
538 : EAP_CODE_RESPONSE, id);
539 0 : if (resp == NULL)
540 0 : return NULL;
541 :
542 0 : ms = wpabuf_put(resp, sizeof(*ms));
543 0 : ms->op_code = MSCHAPV2_OP_CHANGE_PASSWORD;
544 0 : ms->mschapv2_id = req->mschapv2_id + 1;
545 0 : WPA_PUT_BE16(ms->ms_length, ms_len);
546 0 : cp = wpabuf_put(resp, sizeof(*cp));
547 :
548 : /* Encrypted-Password */
549 0 : if (pwhash) {
550 0 : if (encrypt_pw_block_with_password_hash(
551 : new_password, new_password_len,
552 0 : password, cp->encr_password))
553 0 : goto fail;
554 : } else {
555 0 : if (new_password_encrypted_with_old_nt_password_hash(
556 : new_password, new_password_len,
557 0 : password, password_len, cp->encr_password))
558 0 : goto fail;
559 : }
560 :
561 : /* Encrypted-Hash */
562 0 : if (pwhash) {
563 : u8 new_password_hash[16];
564 0 : if (nt_password_hash(new_password, new_password_len,
565 : new_password_hash))
566 0 : goto fail;
567 0 : nt_password_hash_encrypted_with_block(password,
568 : new_password_hash,
569 0 : cp->encr_hash);
570 : } else {
571 0 : if (old_nt_password_hash_encrypted_with_new_nt_password_hash(
572 : new_password, new_password_len,
573 0 : password, password_len, cp->encr_hash))
574 0 : goto fail;
575 : }
576 :
577 : /* Peer-Challenge */
578 0 : if (random_get_bytes(cp->peer_challenge, MSCHAPV2_CHAL_LEN))
579 0 : goto fail;
580 :
581 : /* Reserved, must be zero */
582 0 : os_memset(cp->reserved, 0, 8);
583 :
584 : /* NT-Response */
585 0 : wpa_hexdump(MSG_DEBUG, "EAP-MSCHAPV2: auth_challenge",
586 0 : data->passwd_change_challenge, PASSWD_CHANGE_CHAL_LEN);
587 0 : wpa_hexdump(MSG_DEBUG, "EAP-MSCHAPV2: peer_challenge",
588 0 : cp->peer_challenge, MSCHAPV2_CHAL_LEN);
589 0 : wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: username",
590 : username, username_len);
591 0 : wpa_hexdump_ascii_key(MSG_DEBUG, "EAP-MSCHAPV2: new password",
592 : new_password, new_password_len);
593 0 : generate_nt_response(data->passwd_change_challenge, cp->peer_challenge,
594 : username, username_len,
595 : new_password, new_password_len,
596 0 : cp->nt_response);
597 0 : wpa_hexdump(MSG_DEBUG, "EAP-MSCHAPV2: NT-Response",
598 0 : cp->nt_response, MSCHAPV2_NT_RESPONSE_LEN);
599 :
600 : /* Authenticator response is not really needed yet, but calculate it
601 : * here so that challenges need not be saved. */
602 0 : generate_authenticator_response(new_password, new_password_len,
603 0 : cp->peer_challenge,
604 0 : data->passwd_change_challenge,
605 : username, username_len,
606 0 : cp->nt_response, data->auth_response);
607 0 : data->auth_response_valid = 1;
608 :
609 : /* Likewise, generate master_key here since we have the needed data
610 : * available. */
611 0 : if (nt_password_hash(new_password, new_password_len, password_hash) ||
612 0 : hash_nt_password_hash(password_hash, password_hash_hash) ||
613 0 : get_master_key(password_hash_hash, cp->nt_response,
614 0 : data->master_key)) {
615 0 : data->auth_response_valid = 0;
616 0 : goto fail;
617 : }
618 0 : data->master_key_valid = 1;
619 :
620 : /* Flags */
621 0 : os_memset(cp->flags, 0, 2);
622 :
623 0 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: TX identifier %d mschapv2_id %d "
624 0 : "(change pw)", id, ms->mschapv2_id);
625 :
626 0 : return resp;
627 :
628 : fail:
629 0 : wpabuf_free(resp);
630 0 : return NULL;
631 : }
632 :
633 :
634 : /**
635 : * eap_mschapv2_process - Process an EAP-MSCHAPv2 failure message
636 : * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
637 : * @data: Pointer to private EAP method data from eap_mschapv2_init()
638 : * @ret: Return values from EAP request validation and processing
639 : * @req: Pointer to EAP-MSCHAPv2 header from the request
640 : * @req_len: Length of the EAP-MSCHAPv2 data
641 : * @id: EAP identifier used in th erequest
642 : * Returns: Pointer to allocated EAP response packet (eapRespData) or %NULL if
643 : * no reply available
644 : */
645 3 : static struct wpabuf * eap_mschapv2_failure(struct eap_sm *sm,
646 : struct eap_mschapv2_data *data,
647 : struct eap_method_ret *ret,
648 : const struct eap_mschapv2_hdr *req,
649 : size_t req_len, u8 id)
650 : {
651 : struct wpabuf *resp;
652 3 : const u8 *msdata = (const u8 *) (req + 1);
653 : char *buf;
654 3 : size_t len = req_len - sizeof(*req);
655 3 : int retry = 0;
656 :
657 3 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Received failure");
658 3 : wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: Failure data",
659 : msdata, len);
660 : /*
661 : * eap_mschapv2_failure_txt() expects a nul terminated string, so we
662 : * must allocate a large enough temporary buffer to create that since
663 : * the received message does not include nul termination.
664 : */
665 3 : buf = dup_binstr(msdata, len);
666 3 : if (buf) {
667 3 : retry = eap_mschapv2_failure_txt(sm, data, buf);
668 3 : os_free(buf);
669 : }
670 :
671 3 : ret->ignore = FALSE;
672 3 : ret->methodState = METHOD_DONE;
673 3 : ret->decision = DECISION_FAIL;
674 3 : ret->allowNotifications = FALSE;
675 :
676 3 : if (data->prev_error == ERROR_PASSWD_EXPIRED &&
677 0 : data->passwd_change_version == 3) {
678 0 : struct eap_peer_config *config = eap_get_config(sm);
679 0 : if (config && config->new_password)
680 0 : return eap_mschapv2_change_password(sm, data, ret, req,
681 : id);
682 0 : if (config && config->pending_req_new_password)
683 0 : return NULL;
684 3 : } else if (retry && data->prev_error == ERROR_AUTHENTICATION_FAILURE) {
685 : /* TODO: could try to retry authentication, e.g, after having
686 : * changed the username/password. In this case, EAP MS-CHAP-v2
687 : * Failure Response would not be sent here. */
688 0 : return NULL;
689 : }
690 :
691 : /* Note: Only op_code of the EAP-MSCHAPV2 header is included in failure
692 : * message. */
693 3 : resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, 1,
694 : EAP_CODE_RESPONSE, id);
695 3 : if (resp == NULL)
696 0 : return NULL;
697 :
698 3 : wpabuf_put_u8(resp, MSCHAPV2_OP_FAILURE); /* op_code */
699 :
700 3 : return resp;
701 : }
702 :
703 :
704 105 : static int eap_mschapv2_check_config(struct eap_sm *sm)
705 : {
706 : size_t len;
707 :
708 105 : if (eap_get_config_identity(sm, &len) == NULL) {
709 0 : wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Identity not configured");
710 0 : eap_sm_request_identity(sm);
711 0 : return -1;
712 : }
713 :
714 105 : if (eap_get_config_password(sm, &len) == NULL) {
715 2 : wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Password not configured");
716 2 : eap_sm_request_password(sm);
717 2 : return -1;
718 : }
719 :
720 103 : return 0;
721 : }
722 :
723 :
724 103 : static int eap_mschapv2_check_mslen(struct eap_sm *sm, size_t len,
725 : const struct eap_mschapv2_hdr *ms)
726 : {
727 103 : size_t ms_len = WPA_GET_BE16(ms->ms_length);
728 :
729 103 : if (ms_len == len)
730 103 : return 0;
731 :
732 0 : wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Invalid header: len=%lu "
733 : "ms_len=%lu", (unsigned long) len, (unsigned long) ms_len);
734 0 : if (sm->workaround) {
735 : /* Some authentication servers use invalid ms_len,
736 : * ignore it for interoperability. */
737 0 : wpa_printf(MSG_INFO, "EAP-MSCHAPV2: workaround, ignore"
738 : " invalid ms_len %lu (len %lu)",
739 : (unsigned long) ms_len,
740 : (unsigned long) len);
741 0 : return 0;
742 : }
743 :
744 0 : return -1;
745 : }
746 :
747 :
748 53 : static void eap_mschapv2_copy_challenge(struct eap_mschapv2_data *data,
749 : const struct wpabuf *reqData)
750 : {
751 : /*
752 : * Store a copy of the challenge message, so that it can be processed
753 : * again in case retry is allowed after a possible failure.
754 : */
755 53 : wpabuf_free(data->prev_challenge);
756 53 : data->prev_challenge = wpabuf_dup(reqData);
757 53 : }
758 :
759 :
760 : /**
761 : * eap_mschapv2_process - Process an EAP-MSCHAPv2 request
762 : * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
763 : * @priv: Pointer to private EAP method data from eap_mschapv2_init()
764 : * @ret: Return values from EAP request validation and processing
765 : * @reqData: EAP request to be processed (eapReqData)
766 : * Returns: Pointer to allocated EAP response packet (eapRespData) or %NULL if
767 : * no reply available
768 : */
769 105 : static struct wpabuf * eap_mschapv2_process(struct eap_sm *sm, void *priv,
770 : struct eap_method_ret *ret,
771 : const struct wpabuf *reqData)
772 : {
773 105 : struct eap_mschapv2_data *data = priv;
774 105 : struct eap_peer_config *config = eap_get_config(sm);
775 : const struct eap_mschapv2_hdr *ms;
776 105 : int using_prev_challenge = 0;
777 : const u8 *pos;
778 : size_t len;
779 : u8 id;
780 :
781 105 : if (eap_mschapv2_check_config(sm)) {
782 2 : ret->ignore = TRUE;
783 2 : return NULL;
784 : }
785 :
786 103 : if (config->mschapv2_retry && data->prev_challenge &&
787 0 : data->prev_error == ERROR_AUTHENTICATION_FAILURE) {
788 0 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Replacing pending packet "
789 : "with the previous challenge");
790 :
791 0 : reqData = data->prev_challenge;
792 0 : using_prev_challenge = 1;
793 0 : config->mschapv2_retry = 0;
794 : }
795 :
796 103 : pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, reqData,
797 : &len);
798 103 : if (pos == NULL || len < sizeof(*ms) + 1) {
799 0 : ret->ignore = TRUE;
800 0 : return NULL;
801 : }
802 :
803 103 : ms = (const struct eap_mschapv2_hdr *) pos;
804 103 : if (eap_mschapv2_check_mslen(sm, len, ms)) {
805 0 : ret->ignore = TRUE;
806 0 : return NULL;
807 : }
808 :
809 103 : id = eap_get_id(reqData);
810 103 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: RX identifier %d mschapv2_id %d",
811 103 : id, ms->mschapv2_id);
812 :
813 103 : switch (ms->op_code) {
814 : case MSCHAPV2_OP_CHALLENGE:
815 53 : if (!using_prev_challenge)
816 53 : eap_mschapv2_copy_challenge(data, reqData);
817 53 : return eap_mschapv2_challenge(sm, data, ret, ms, len, id);
818 : case MSCHAPV2_OP_SUCCESS:
819 47 : return eap_mschapv2_success(sm, data, ret, ms, len, id);
820 : case MSCHAPV2_OP_FAILURE:
821 3 : return eap_mschapv2_failure(sm, data, ret, ms, len, id);
822 : default:
823 0 : wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Unknown op %d - ignored",
824 0 : ms->op_code);
825 0 : ret->ignore = TRUE;
826 0 : return NULL;
827 : }
828 : }
829 :
830 :
831 20 : static Boolean eap_mschapv2_isKeyAvailable(struct eap_sm *sm, void *priv)
832 : {
833 20 : struct eap_mschapv2_data *data = priv;
834 20 : return data->success && data->master_key_valid;
835 : }
836 :
837 :
838 20 : static u8 * eap_mschapv2_getKey(struct eap_sm *sm, void *priv, size_t *len)
839 : {
840 20 : struct eap_mschapv2_data *data = priv;
841 : u8 *key;
842 : int key_len;
843 :
844 20 : if (!data->master_key_valid || !data->success)
845 0 : return NULL;
846 :
847 20 : key_len = 2 * MSCHAPV2_KEY_LEN;
848 :
849 20 : key = os_malloc(key_len);
850 20 : if (key == NULL)
851 0 : return NULL;
852 :
853 : /* MSK = server MS-MPPE-Recv-Key | MS-MPPE-Send-Key, i.e.,
854 : * peer MS-MPPE-Send-Key | MS-MPPE-Recv-Key */
855 20 : get_asymetric_start_key(data->master_key, key, MSCHAPV2_KEY_LEN, 1, 0);
856 20 : get_asymetric_start_key(data->master_key, key + MSCHAPV2_KEY_LEN,
857 : MSCHAPV2_KEY_LEN, 0, 0);
858 :
859 20 : wpa_hexdump_key(MSG_DEBUG, "EAP-MSCHAPV2: Derived key",
860 : key, key_len);
861 :
862 20 : *len = key_len;
863 20 : return key;
864 : }
865 :
866 :
867 : /**
868 : * eap_peer_mschapv2_register - Register EAP-MSCHAPv2 peer method
869 : * Returns: 0 on success, -1 on failure
870 : *
871 : * This function is used to register EAP-MSCHAPv2 peer method into the EAP
872 : * method list.
873 : */
874 30 : int eap_peer_mschapv2_register(void)
875 : {
876 : struct eap_method *eap;
877 : int ret;
878 :
879 30 : eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
880 : EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2,
881 : "MSCHAPV2");
882 30 : if (eap == NULL)
883 0 : return -1;
884 :
885 30 : eap->init = eap_mschapv2_init;
886 30 : eap->deinit = eap_mschapv2_deinit;
887 30 : eap->process = eap_mschapv2_process;
888 30 : eap->isKeyAvailable = eap_mschapv2_isKeyAvailable;
889 30 : eap->getKey = eap_mschapv2_getKey;
890 :
891 30 : ret = eap_peer_method_register(eap);
892 30 : if (ret)
893 0 : eap_peer_method_free(eap);
894 30 : return ret;
895 : }
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