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 42 : static void * eap_mschapv2_init(struct eap_sm *sm)
105 : {
106 : struct eap_mschapv2_data *data;
107 42 : data = os_zalloc(sizeof(*data));
108 42 : if (data == NULL)
109 0 : return NULL;
110 :
111 42 : 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 42 : 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 42 : data->phase2 = sm->init_phase2;
132 :
133 42 : return data;
134 : }
135 :
136 :
137 42 : static void eap_mschapv2_deinit(struct eap_sm *sm, void *priv)
138 : {
139 42 : struct eap_mschapv2_data *data = priv;
140 42 : os_free(data->peer_challenge);
141 42 : os_free(data->auth_challenge);
142 42 : wpabuf_free(data->prev_challenge);
143 42 : os_free(data);
144 42 : }
145 :
146 :
147 46 : 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 46 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Generating Challenge Response");
161 :
162 46 : identity = eap_get_config_identity(sm, &identity_len);
163 46 : password = eap_get_config_password2(sm, &password_len, &pwhash);
164 46 : if (identity == NULL || password == NULL)
165 0 : return NULL;
166 :
167 46 : ms_len = sizeof(*ms) + 1 + sizeof(*r) + identity_len;
168 46 : resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, ms_len,
169 : EAP_CODE_RESPONSE, id);
170 46 : if (resp == NULL)
171 0 : return NULL;
172 :
173 46 : ms = wpabuf_put(resp, sizeof(*ms));
174 46 : ms->op_code = MSCHAPV2_OP_RESPONSE;
175 46 : ms->mschapv2_id = mschapv2_id;
176 46 : 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 46 : WPA_PUT_BE16(ms->ms_length, ms_len);
186 :
187 46 : wpabuf_put_u8(resp, sizeof(*r)); /* Value-Size */
188 :
189 : /* Response */
190 46 : r = wpabuf_put(resp, sizeof(*r));
191 46 : peer_challenge = r->peer_challenge;
192 46 : 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 42 : } else if (random_get_bytes(peer_challenge, MSCHAPV2_CHAL_LEN)) {
198 0 : wpabuf_free(resp);
199 0 : return NULL;
200 : }
201 46 : os_memset(r->reserved, 0, 8);
202 46 : 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 46 : if (mschapv2_derive_response(identity, identity_len, password,
208 : password_len, pwhash, auth_challenge,
209 46 : peer_challenge, r->nt_response,
210 46 : 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 46 : data->auth_response_valid = 1;
217 46 : data->master_key_valid = 1;
218 :
219 46 : r->flags = 0; /* reserved, must be zero */
220 :
221 46 : wpabuf_put_data(resp, identity, identity_len);
222 46 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: TX identifier %d mschapv2_id %d "
223 46 : "(response)", id, ms->mschapv2_id);
224 46 : 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 46 : 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 92 : if (eap_get_config_identity(sm, &len) == NULL ||
248 46 : eap_get_config_password(sm, &len) == NULL)
249 0 : return NULL;
250 :
251 46 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Received challenge");
252 46 : 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 46 : pos = (const u8 *) (req + 1);
259 46 : challenge_len = *pos++;
260 46 : len = req_len - sizeof(*req) - 1;
261 46 : 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 46 : 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 46 : 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 46 : challenge = pos;
282 46 : pos += challenge_len;
283 46 : len -= challenge_len;
284 46 : wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: Authentication Servername",
285 : pos, len);
286 :
287 46 : ret->ignore = FALSE;
288 46 : ret->methodState = METHOD_MAY_CONT;
289 46 : ret->decision = DECISION_FAIL;
290 46 : ret->allowNotifications = TRUE;
291 :
292 46 : 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 : os_free(config->password);
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 : }
317 0 : os_free(config->new_password);
318 : } else {
319 0 : config->password = config->new_password;
320 0 : config->password_len = config->new_password_len;
321 : }
322 0 : config->new_password = NULL;
323 0 : config->new_password_len = 0;
324 : }
325 0 : }
326 :
327 :
328 : /**
329 : * eap_mschapv2_process - Process an EAP-MSCHAPv2 success message
330 : * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
331 : * @data: Pointer to private EAP method data from eap_mschapv2_init()
332 : * @ret: Return values from EAP request validation and processing
333 : * @req: Pointer to EAP-MSCHAPv2 header from the request
334 : * @req_len: Length of the EAP-MSCHAPv2 data
335 : * @id: EAP identifier used in th erequest
336 : * Returns: Pointer to allocated EAP response packet (eapRespData) or %NULL if
337 : * no reply available
338 : */
339 44 : static struct wpabuf * eap_mschapv2_success(struct eap_sm *sm,
340 : struct eap_mschapv2_data *data,
341 : struct eap_method_ret *ret,
342 : const struct eap_mschapv2_hdr *req,
343 : size_t req_len, u8 id)
344 : {
345 : struct wpabuf *resp;
346 : const u8 *pos;
347 : size_t len;
348 :
349 44 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Received success");
350 44 : len = req_len - sizeof(*req);
351 44 : pos = (const u8 *) (req + 1);
352 88 : if (!data->auth_response_valid ||
353 44 : mschapv2_verify_auth_response(data->auth_response, pos, len)) {
354 0 : wpa_printf(MSG_WARNING, "EAP-MSCHAPV2: Invalid authenticator "
355 : "response in success request");
356 0 : ret->methodState = METHOD_DONE;
357 0 : ret->decision = DECISION_FAIL;
358 0 : return NULL;
359 : }
360 44 : pos += 2 + 2 * MSCHAPV2_AUTH_RESPONSE_LEN;
361 44 : len -= 2 + 2 * MSCHAPV2_AUTH_RESPONSE_LEN;
362 132 : while (len > 0 && *pos == ' ') {
363 44 : pos++;
364 44 : len--;
365 : }
366 44 : wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: Success message",
367 : pos, len);
368 44 : wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Authentication succeeded");
369 :
370 : /* Note: Only op_code of the EAP-MSCHAPV2 header is included in success
371 : * message. */
372 44 : resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, 1,
373 : EAP_CODE_RESPONSE, id);
374 44 : if (resp == NULL) {
375 0 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Failed to allocate "
376 : "buffer for success response");
377 0 : ret->ignore = TRUE;
378 0 : return NULL;
379 : }
380 :
381 44 : wpabuf_put_u8(resp, MSCHAPV2_OP_SUCCESS); /* op_code */
382 :
383 44 : ret->methodState = METHOD_DONE;
384 44 : ret->decision = DECISION_UNCOND_SUCC;
385 44 : ret->allowNotifications = FALSE;
386 44 : data->success = 1;
387 :
388 44 : if (data->prev_error == ERROR_PASSWD_EXPIRED)
389 0 : eap_mschapv2_password_changed(sm, data);
390 :
391 44 : return resp;
392 : }
393 :
394 :
395 2 : static int eap_mschapv2_failure_txt(struct eap_sm *sm,
396 : struct eap_mschapv2_data *data, char *txt)
397 : {
398 2 : char *pos, *msg = "";
399 2 : int retry = 1;
400 2 : struct eap_peer_config *config = eap_get_config(sm);
401 :
402 : /* For example:
403 : * E=691 R=1 C=<32 octets hex challenge> V=3 M=Authentication Failure
404 : */
405 :
406 2 : pos = txt;
407 :
408 2 : if (pos && os_strncmp(pos, "E=", 2) == 0) {
409 2 : pos += 2;
410 2 : data->prev_error = atoi(pos);
411 2 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: error %d",
412 : data->prev_error);
413 2 : pos = os_strchr(pos, ' ');
414 2 : if (pos)
415 2 : pos++;
416 : }
417 :
418 2 : if (pos && os_strncmp(pos, "R=", 2) == 0) {
419 2 : pos += 2;
420 2 : retry = atoi(pos);
421 2 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: retry is %sallowed",
422 : retry == 1 ? "" : "not ");
423 2 : pos = os_strchr(pos, ' ');
424 2 : if (pos)
425 2 : pos++;
426 : }
427 :
428 4 : if (pos && os_strncmp(pos, "C=", 2) == 0) {
429 : int hex_len;
430 2 : pos += 2;
431 2 : hex_len = os_strchr(pos, ' ') - (char *) pos;
432 2 : if (hex_len == PASSWD_CHANGE_CHAL_LEN * 2) {
433 2 : if (hexstr2bin(pos, data->passwd_change_challenge,
434 : PASSWD_CHANGE_CHAL_LEN)) {
435 0 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: invalid "
436 : "failure challenge");
437 : } else {
438 2 : wpa_hexdump(MSG_DEBUG, "EAP-MSCHAPV2: failure "
439 : "challenge",
440 2 : data->passwd_change_challenge,
441 : PASSWD_CHANGE_CHAL_LEN);
442 2 : data->passwd_change_challenge_valid = 1;
443 : }
444 : } else {
445 0 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: invalid failure "
446 : "challenge len %d", hex_len);
447 : }
448 2 : pos = os_strchr(pos, ' ');
449 2 : if (pos)
450 2 : pos++;
451 : } else {
452 0 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: required challenge field "
453 : "was not present in failure message");
454 : }
455 :
456 2 : if (pos && os_strncmp(pos, "V=", 2) == 0) {
457 2 : pos += 2;
458 2 : data->passwd_change_version = atoi(pos);
459 2 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: password changing "
460 : "protocol version %d", data->passwd_change_version);
461 2 : pos = os_strchr(pos, ' ');
462 2 : if (pos)
463 2 : pos++;
464 : }
465 :
466 2 : if (pos && os_strncmp(pos, "M=", 2) == 0) {
467 2 : pos += 2;
468 2 : msg = pos;
469 : }
470 2 : wpa_msg(sm->msg_ctx, MSG_WARNING,
471 : "EAP-MSCHAPV2: failure message: '%s' (retry %sallowed, error "
472 : "%d)",
473 : msg, retry == 1 ? "" : "not ", data->prev_error);
474 2 : if (data->prev_error == ERROR_PASSWD_EXPIRED &&
475 0 : data->passwd_change_version == 3 && config) {
476 0 : if (config->new_password == NULL) {
477 0 : wpa_msg(sm->msg_ctx, MSG_INFO,
478 : "EAP-MSCHAPV2: Password expired - password "
479 : "change required");
480 0 : eap_sm_request_new_password(sm);
481 : }
482 2 : } else if (retry == 1 && config) {
483 : /* TODO: could prevent the current password from being used
484 : * again at least for some period of time */
485 0 : if (!config->mschapv2_retry)
486 0 : eap_sm_request_identity(sm);
487 0 : eap_sm_request_password(sm);
488 0 : config->mschapv2_retry = 1;
489 2 : } else if (config) {
490 : /* TODO: prevent retries using same username/password */
491 2 : config->mschapv2_retry = 0;
492 : }
493 :
494 2 : return retry == 1;
495 : }
496 :
497 :
498 0 : static struct wpabuf * eap_mschapv2_change_password(
499 : struct eap_sm *sm, struct eap_mschapv2_data *data,
500 : struct eap_method_ret *ret, const struct eap_mschapv2_hdr *req, u8 id)
501 : {
502 : struct wpabuf *resp;
503 : int ms_len;
504 : const u8 *username, *password, *new_password;
505 : size_t username_len, password_len, new_password_len;
506 : struct eap_mschapv2_hdr *ms;
507 : struct ms_change_password *cp;
508 : u8 password_hash[16], password_hash_hash[16];
509 : int pwhash;
510 :
511 0 : username = eap_get_config_identity(sm, &username_len);
512 0 : password = eap_get_config_password2(sm, &password_len, &pwhash);
513 0 : new_password = eap_get_config_new_password(sm, &new_password_len);
514 0 : if (username == NULL || password == NULL || new_password == NULL)
515 0 : return NULL;
516 :
517 0 : username = mschapv2_remove_domain(username, &username_len);
518 :
519 0 : ret->ignore = FALSE;
520 0 : ret->methodState = METHOD_MAY_CONT;
521 0 : ret->decision = DECISION_COND_SUCC;
522 0 : ret->allowNotifications = TRUE;
523 :
524 0 : ms_len = sizeof(*ms) + sizeof(*cp);
525 0 : resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, ms_len,
526 : EAP_CODE_RESPONSE, id);
527 0 : if (resp == NULL)
528 0 : return NULL;
529 :
530 0 : ms = wpabuf_put(resp, sizeof(*ms));
531 0 : ms->op_code = MSCHAPV2_OP_CHANGE_PASSWORD;
532 0 : ms->mschapv2_id = req->mschapv2_id + 1;
533 0 : WPA_PUT_BE16(ms->ms_length, ms_len);
534 0 : cp = wpabuf_put(resp, sizeof(*cp));
535 :
536 : /* Encrypted-Password */
537 0 : if (pwhash) {
538 0 : if (encrypt_pw_block_with_password_hash(
539 : new_password, new_password_len,
540 0 : password, cp->encr_password))
541 0 : goto fail;
542 : } else {
543 0 : if (new_password_encrypted_with_old_nt_password_hash(
544 : new_password, new_password_len,
545 0 : password, password_len, cp->encr_password))
546 0 : goto fail;
547 : }
548 :
549 : /* Encrypted-Hash */
550 0 : if (pwhash) {
551 : u8 new_password_hash[16];
552 0 : nt_password_hash(new_password, new_password_len,
553 : new_password_hash);
554 0 : nt_password_hash_encrypted_with_block(password,
555 : new_password_hash,
556 0 : cp->encr_hash);
557 : } else {
558 0 : old_nt_password_hash_encrypted_with_new_nt_password_hash(
559 : new_password, new_password_len,
560 0 : password, password_len, cp->encr_hash);
561 : }
562 :
563 : /* Peer-Challenge */
564 0 : if (random_get_bytes(cp->peer_challenge, MSCHAPV2_CHAL_LEN))
565 0 : goto fail;
566 :
567 : /* Reserved, must be zero */
568 0 : os_memset(cp->reserved, 0, 8);
569 :
570 : /* NT-Response */
571 0 : wpa_hexdump(MSG_DEBUG, "EAP-MSCHAPV2: auth_challenge",
572 0 : data->passwd_change_challenge, PASSWD_CHANGE_CHAL_LEN);
573 0 : wpa_hexdump(MSG_DEBUG, "EAP-MSCHAPV2: peer_challenge",
574 0 : cp->peer_challenge, MSCHAPV2_CHAL_LEN);
575 0 : wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: username",
576 : username, username_len);
577 0 : wpa_hexdump_ascii_key(MSG_DEBUG, "EAP-MSCHAPV2: new password",
578 : new_password, new_password_len);
579 0 : generate_nt_response(data->passwd_change_challenge, cp->peer_challenge,
580 : username, username_len,
581 : new_password, new_password_len,
582 0 : cp->nt_response);
583 0 : wpa_hexdump(MSG_DEBUG, "EAP-MSCHAPV2: NT-Response",
584 0 : cp->nt_response, MSCHAPV2_NT_RESPONSE_LEN);
585 :
586 : /* Authenticator response is not really needed yet, but calculate it
587 : * here so that challenges need not be saved. */
588 0 : generate_authenticator_response(new_password, new_password_len,
589 0 : cp->peer_challenge,
590 0 : data->passwd_change_challenge,
591 : username, username_len,
592 0 : cp->nt_response, data->auth_response);
593 0 : data->auth_response_valid = 1;
594 :
595 : /* Likewise, generate master_key here since we have the needed data
596 : * available. */
597 0 : nt_password_hash(new_password, new_password_len, password_hash);
598 0 : hash_nt_password_hash(password_hash, password_hash_hash);
599 0 : get_master_key(password_hash_hash, cp->nt_response, data->master_key);
600 0 : data->master_key_valid = 1;
601 :
602 : /* Flags */
603 0 : os_memset(cp->flags, 0, 2);
604 :
605 0 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: TX identifier %d mschapv2_id %d "
606 0 : "(change pw)", id, ms->mschapv2_id);
607 :
608 0 : return resp;
609 :
610 : fail:
611 0 : wpabuf_free(resp);
612 0 : return NULL;
613 : }
614 :
615 :
616 : /**
617 : * eap_mschapv2_process - Process an EAP-MSCHAPv2 failure message
618 : * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
619 : * @data: Pointer to private EAP method data from eap_mschapv2_init()
620 : * @ret: Return values from EAP request validation and processing
621 : * @req: Pointer to EAP-MSCHAPv2 header from the request
622 : * @req_len: Length of the EAP-MSCHAPv2 data
623 : * @id: EAP identifier used in th erequest
624 : * Returns: Pointer to allocated EAP response packet (eapRespData) or %NULL if
625 : * no reply available
626 : */
627 2 : static struct wpabuf * eap_mschapv2_failure(struct eap_sm *sm,
628 : struct eap_mschapv2_data *data,
629 : struct eap_method_ret *ret,
630 : const struct eap_mschapv2_hdr *req,
631 : size_t req_len, u8 id)
632 : {
633 : struct wpabuf *resp;
634 2 : const u8 *msdata = (const u8 *) (req + 1);
635 : char *buf;
636 2 : size_t len = req_len - sizeof(*req);
637 2 : int retry = 0;
638 :
639 2 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Received failure");
640 2 : wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: Failure data",
641 : msdata, len);
642 : /*
643 : * eap_mschapv2_failure_txt() expects a nul terminated string, so we
644 : * must allocate a large enough temporary buffer to create that since
645 : * the received message does not include nul termination.
646 : */
647 2 : buf = dup_binstr(msdata, len);
648 2 : if (buf) {
649 2 : retry = eap_mschapv2_failure_txt(sm, data, buf);
650 2 : os_free(buf);
651 : }
652 :
653 2 : ret->ignore = FALSE;
654 2 : ret->methodState = METHOD_DONE;
655 2 : ret->decision = DECISION_FAIL;
656 2 : ret->allowNotifications = FALSE;
657 :
658 2 : if (data->prev_error == ERROR_PASSWD_EXPIRED &&
659 0 : data->passwd_change_version == 3) {
660 0 : struct eap_peer_config *config = eap_get_config(sm);
661 0 : if (config && config->new_password)
662 0 : return eap_mschapv2_change_password(sm, data, ret, req,
663 : id);
664 0 : if (config && config->pending_req_new_password)
665 0 : return NULL;
666 2 : } else if (retry && data->prev_error == ERROR_AUTHENTICATION_FAILURE) {
667 : /* TODO: could try to retry authentication, e.g, after having
668 : * changed the username/password. In this case, EAP MS-CHAP-v2
669 : * Failure Response would not be sent here. */
670 0 : return NULL;
671 : }
672 :
673 : /* Note: Only op_code of the EAP-MSCHAPV2 header is included in failure
674 : * message. */
675 2 : resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, 1,
676 : EAP_CODE_RESPONSE, id);
677 2 : if (resp == NULL)
678 0 : return NULL;
679 :
680 2 : wpabuf_put_u8(resp, MSCHAPV2_OP_FAILURE); /* op_code */
681 :
682 2 : return resp;
683 : }
684 :
685 :
686 94 : static int eap_mschapv2_check_config(struct eap_sm *sm)
687 : {
688 : size_t len;
689 :
690 94 : if (eap_get_config_identity(sm, &len) == NULL) {
691 0 : wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Identity not configured");
692 0 : eap_sm_request_identity(sm);
693 0 : return -1;
694 : }
695 :
696 94 : if (eap_get_config_password(sm, &len) == NULL) {
697 2 : wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Password not configured");
698 2 : eap_sm_request_password(sm);
699 2 : return -1;
700 : }
701 :
702 92 : return 0;
703 : }
704 :
705 :
706 92 : static int eap_mschapv2_check_mslen(struct eap_sm *sm, size_t len,
707 : const struct eap_mschapv2_hdr *ms)
708 : {
709 92 : size_t ms_len = WPA_GET_BE16(ms->ms_length);
710 :
711 92 : if (ms_len == len)
712 92 : return 0;
713 :
714 0 : wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Invalid header: len=%lu "
715 : "ms_len=%lu", (unsigned long) len, (unsigned long) ms_len);
716 0 : if (sm->workaround) {
717 : /* Some authentication servers use invalid ms_len,
718 : * ignore it for interoperability. */
719 0 : wpa_printf(MSG_INFO, "EAP-MSCHAPV2: workaround, ignore"
720 : " invalid ms_len %lu (len %lu)",
721 : (unsigned long) ms_len,
722 : (unsigned long) len);
723 0 : return 0;
724 : }
725 :
726 0 : return -1;
727 : }
728 :
729 :
730 46 : static void eap_mschapv2_copy_challenge(struct eap_mschapv2_data *data,
731 : const struct wpabuf *reqData)
732 : {
733 : /*
734 : * Store a copy of the challenge message, so that it can be processed
735 : * again in case retry is allowed after a possible failure.
736 : */
737 46 : wpabuf_free(data->prev_challenge);
738 46 : data->prev_challenge = wpabuf_dup(reqData);
739 46 : }
740 :
741 :
742 : /**
743 : * eap_mschapv2_process - Process an EAP-MSCHAPv2 request
744 : * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
745 : * @priv: Pointer to private EAP method data from eap_mschapv2_init()
746 : * @ret: Return values from EAP request validation and processing
747 : * @reqData: EAP request to be processed (eapReqData)
748 : * Returns: Pointer to allocated EAP response packet (eapRespData) or %NULL if
749 : * no reply available
750 : */
751 94 : static struct wpabuf * eap_mschapv2_process(struct eap_sm *sm, void *priv,
752 : struct eap_method_ret *ret,
753 : const struct wpabuf *reqData)
754 : {
755 94 : struct eap_mschapv2_data *data = priv;
756 94 : struct eap_peer_config *config = eap_get_config(sm);
757 : const struct eap_mschapv2_hdr *ms;
758 94 : int using_prev_challenge = 0;
759 : const u8 *pos;
760 : size_t len;
761 : u8 id;
762 :
763 94 : if (eap_mschapv2_check_config(sm)) {
764 2 : ret->ignore = TRUE;
765 2 : return NULL;
766 : }
767 :
768 92 : if (config->mschapv2_retry && data->prev_challenge &&
769 0 : data->prev_error == ERROR_AUTHENTICATION_FAILURE) {
770 0 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Replacing pending packet "
771 : "with the previous challenge");
772 :
773 0 : reqData = data->prev_challenge;
774 0 : using_prev_challenge = 1;
775 0 : config->mschapv2_retry = 0;
776 : }
777 :
778 92 : pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, reqData,
779 : &len);
780 92 : if (pos == NULL || len < sizeof(*ms) + 1) {
781 0 : ret->ignore = TRUE;
782 0 : return NULL;
783 : }
784 :
785 92 : ms = (const struct eap_mschapv2_hdr *) pos;
786 92 : if (eap_mschapv2_check_mslen(sm, len, ms)) {
787 0 : ret->ignore = TRUE;
788 0 : return NULL;
789 : }
790 :
791 92 : id = eap_get_id(reqData);
792 92 : wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: RX identifier %d mschapv2_id %d",
793 92 : id, ms->mschapv2_id);
794 :
795 92 : switch (ms->op_code) {
796 : case MSCHAPV2_OP_CHALLENGE:
797 46 : if (!using_prev_challenge)
798 46 : eap_mschapv2_copy_challenge(data, reqData);
799 46 : return eap_mschapv2_challenge(sm, data, ret, ms, len, id);
800 : case MSCHAPV2_OP_SUCCESS:
801 44 : return eap_mschapv2_success(sm, data, ret, ms, len, id);
802 : case MSCHAPV2_OP_FAILURE:
803 2 : return eap_mschapv2_failure(sm, data, ret, ms, len, id);
804 : default:
805 0 : wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Unknown op %d - ignored",
806 0 : ms->op_code);
807 0 : ret->ignore = TRUE;
808 0 : return NULL;
809 : }
810 : }
811 :
812 :
813 20 : static Boolean eap_mschapv2_isKeyAvailable(struct eap_sm *sm, void *priv)
814 : {
815 20 : struct eap_mschapv2_data *data = priv;
816 20 : return data->success && data->master_key_valid;
817 : }
818 :
819 :
820 20 : static u8 * eap_mschapv2_getKey(struct eap_sm *sm, void *priv, size_t *len)
821 : {
822 20 : struct eap_mschapv2_data *data = priv;
823 : u8 *key;
824 : int key_len;
825 :
826 20 : if (!data->master_key_valid || !data->success)
827 0 : return NULL;
828 :
829 20 : key_len = 2 * MSCHAPV2_KEY_LEN;
830 :
831 20 : key = os_malloc(key_len);
832 20 : if (key == NULL)
833 0 : return NULL;
834 :
835 : /* MSK = server MS-MPPE-Recv-Key | MS-MPPE-Send-Key, i.e.,
836 : * peer MS-MPPE-Send-Key | MS-MPPE-Recv-Key */
837 20 : get_asymetric_start_key(data->master_key, key, MSCHAPV2_KEY_LEN, 1, 0);
838 20 : get_asymetric_start_key(data->master_key, key + MSCHAPV2_KEY_LEN,
839 : MSCHAPV2_KEY_LEN, 0, 0);
840 :
841 20 : wpa_hexdump_key(MSG_DEBUG, "EAP-MSCHAPV2: Derived key",
842 : key, key_len);
843 :
844 20 : *len = key_len;
845 20 : return key;
846 : }
847 :
848 :
849 : /**
850 : * eap_peer_mschapv2_register - Register EAP-MSCHAPv2 peer method
851 : * Returns: 0 on success, -1 on failure
852 : *
853 : * This function is used to register EAP-MSCHAPv2 peer method into the EAP
854 : * method list.
855 : */
856 4 : int eap_peer_mschapv2_register(void)
857 : {
858 : struct eap_method *eap;
859 : int ret;
860 :
861 4 : eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
862 : EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2,
863 : "MSCHAPV2");
864 4 : if (eap == NULL)
865 0 : return -1;
866 :
867 4 : eap->init = eap_mschapv2_init;
868 4 : eap->deinit = eap_mschapv2_deinit;
869 4 : eap->process = eap_mschapv2_process;
870 4 : eap->isKeyAvailable = eap_mschapv2_isKeyAvailable;
871 4 : eap->getKey = eap_mschapv2_getKey;
872 :
873 4 : ret = eap_peer_method_register(eap);
874 4 : if (ret)
875 0 : eap_peer_method_free(eap);
876 4 : return ret;
877 : }
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