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1 /*
2  * hostapd / EAP-TTLS (RFC 5281)
3  * Copyright (c) 2004-2008, Jouni Malinen <j@w1.fi>
4  *
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.
8  *
9  * Alternatively, this software may be distributed under the terms of BSD
10  * license.
11  *
12  * See README and COPYING for more details.
13  */
14 
15 #include "includes.h"
16 
17 #include "common.h"
18 #include "eap_server/eap_i.h"
19 #include "eap_server/eap_tls_common.h"
20 #include "ms_funcs.h"
21 #include "sha1.h"
22 #include "eap_common/chap.h"
23 #include "tls.h"
24 #include "eap_common/eap_ttls.h"
25 
26 
27 /* Maximum supported TTLS version
28  * 0 = RFC 5281
29  * 1 = draft-funk-eap-ttls-v1-00.txt
30  */
31 #ifndef EAP_TTLS_VERSION
32 #define EAP_TTLS_VERSION 0 /* TTLSv1 implementation is not yet complete */
33 #endif /* EAP_TTLS_VERSION */
34 
35 
36 #define MSCHAPV2_KEY_LEN 16
37 
38 
39 static void eap_ttls_reset(struct eap_sm *sm, void *priv);
40 
41 
42 struct eap_ttls_data {
43 	struct eap_ssl_data ssl;
44 	enum {
45 		START, PHASE1, PHASE2_START, PHASE2_METHOD,
46 		PHASE2_MSCHAPV2_RESP, PHASE_FINISHED, SUCCESS, FAILURE
47 	} state;
48 
49 	int ttls_version;
50 	int force_version;
51 	const struct eap_method *phase2_method;
52 	void *phase2_priv;
53 	int mschapv2_resp_ok;
54 	u8 mschapv2_auth_response[20];
55 	u8 mschapv2_ident;
56 	int tls_ia_configured;
57 	struct wpabuf *pending_phase2_eap_resp;
58 	int tnc_started;
59 };
60 
61 
eap_ttls_state_txt(int state)62 static const char * eap_ttls_state_txt(int state)
63 {
64 	switch (state) {
65 	case START:
66 		return "START";
67 	case PHASE1:
68 		return "PHASE1";
69 	case PHASE2_START:
70 		return "PHASE2_START";
71 	case PHASE2_METHOD:
72 		return "PHASE2_METHOD";
73 	case PHASE2_MSCHAPV2_RESP:
74 		return "PHASE2_MSCHAPV2_RESP";
75 	case PHASE_FINISHED:
76 		return "PHASE_FINISHED";
77 	case SUCCESS:
78 		return "SUCCESS";
79 	case FAILURE:
80 		return "FAILURE";
81 	default:
82 		return "Unknown?!";
83 	}
84 }
85 
86 
eap_ttls_state(struct eap_ttls_data * data,int state)87 static void eap_ttls_state(struct eap_ttls_data *data, int state)
88 {
89 	wpa_printf(MSG_DEBUG, "EAP-TTLS: %s -> %s",
90 		   eap_ttls_state_txt(data->state),
91 		   eap_ttls_state_txt(state));
92 	data->state = state;
93 }
94 
95 
eap_ttls_avp_hdr(u8 * avphdr,u32 avp_code,u32 vendor_id,int mandatory,size_t len)96 static u8 * eap_ttls_avp_hdr(u8 *avphdr, u32 avp_code, u32 vendor_id,
97 			     int mandatory, size_t len)
98 {
99 	struct ttls_avp_vendor *avp;
100 	u8 flags;
101 	size_t hdrlen;
102 
103 	avp = (struct ttls_avp_vendor *) avphdr;
104 	flags = mandatory ? AVP_FLAGS_MANDATORY : 0;
105 	if (vendor_id) {
106 		flags |= AVP_FLAGS_VENDOR;
107 		hdrlen = sizeof(*avp);
108 		avp->vendor_id = host_to_be32(vendor_id);
109 	} else {
110 		hdrlen = sizeof(struct ttls_avp);
111 	}
112 
113 	avp->avp_code = host_to_be32(avp_code);
114 	avp->avp_length = host_to_be32((flags << 24) | (hdrlen + len));
115 
116 	return avphdr + hdrlen;
117 }
118 
119 
eap_ttls_avp_encapsulate(struct wpabuf * resp,u32 avp_code,int mandatory)120 static struct wpabuf * eap_ttls_avp_encapsulate(struct wpabuf *resp,
121 						u32 avp_code, int mandatory)
122 {
123 	struct wpabuf *avp;
124 	u8 *pos;
125 
126 	avp = wpabuf_alloc(sizeof(struct ttls_avp) + wpabuf_len(resp) + 4);
127 	if (avp == NULL) {
128 		wpabuf_free(resp);
129 		return NULL;
130 	}
131 
132 	pos = eap_ttls_avp_hdr(wpabuf_mhead(avp), avp_code, 0, mandatory,
133 			       wpabuf_len(resp));
134 	os_memcpy(pos, wpabuf_head(resp), wpabuf_len(resp));
135 	pos += wpabuf_len(resp);
136 	AVP_PAD((const u8 *) wpabuf_head(avp), pos);
137 	wpabuf_free(resp);
138 	wpabuf_put(avp, pos - (u8 *) wpabuf_head(avp));
139 	return avp;
140 }
141 
142 
143 struct eap_ttls_avp {
144 	 /* Note: eap is allocated memory; caller is responsible for freeing
145 	  * it. All the other pointers are pointing to the packet data, i.e.,
146 	  * they must not be freed separately. */
147 	u8 *eap;
148 	size_t eap_len;
149 	u8 *user_name;
150 	size_t user_name_len;
151 	u8 *user_password;
152 	size_t user_password_len;
153 	u8 *chap_challenge;
154 	size_t chap_challenge_len;
155 	u8 *chap_password;
156 	size_t chap_password_len;
157 	u8 *mschap_challenge;
158 	size_t mschap_challenge_len;
159 	u8 *mschap_response;
160 	size_t mschap_response_len;
161 	u8 *mschap2_response;
162 	size_t mschap2_response_len;
163 };
164 
165 
eap_ttls_avp_parse(u8 * buf,size_t len,struct eap_ttls_avp * parse)166 static int eap_ttls_avp_parse(u8 *buf, size_t len, struct eap_ttls_avp *parse)
167 {
168 	struct ttls_avp *avp;
169 	u8 *pos;
170 	int left;
171 
172 	pos = buf;
173 	left = len;
174 	os_memset(parse, 0, sizeof(*parse));
175 
176 	while (left > 0) {
177 		u32 avp_code, avp_length, vendor_id = 0;
178 		u8 avp_flags, *dpos;
179 		size_t pad, dlen;
180 		avp = (struct ttls_avp *) pos;
181 		avp_code = be_to_host32(avp->avp_code);
182 		avp_length = be_to_host32(avp->avp_length);
183 		avp_flags = (avp_length >> 24) & 0xff;
184 		avp_length &= 0xffffff;
185 		wpa_printf(MSG_DEBUG, "EAP-TTLS: AVP: code=%d flags=0x%02x "
186 			   "length=%d", (int) avp_code, avp_flags,
187 			   (int) avp_length);
188 		if ((int) avp_length > left) {
189 			wpa_printf(MSG_WARNING, "EAP-TTLS: AVP overflow "
190 				   "(len=%d, left=%d) - dropped",
191 				   (int) avp_length, left);
192 			goto fail;
193 		}
194 		if (avp_length < sizeof(*avp)) {
195 			wpa_printf(MSG_WARNING, "EAP-TTLS: Invalid AVP length "
196 				   "%d", avp_length);
197 			goto fail;
198 		}
199 		dpos = (u8 *) (avp + 1);
200 		dlen = avp_length - sizeof(*avp);
201 		if (avp_flags & AVP_FLAGS_VENDOR) {
202 			if (dlen < 4) {
203 				wpa_printf(MSG_WARNING, "EAP-TTLS: vendor AVP "
204 					   "underflow");
205 				goto fail;
206 			}
207 			vendor_id = be_to_host32(* (be32 *) dpos);
208 			wpa_printf(MSG_DEBUG, "EAP-TTLS: AVP vendor_id %d",
209 				   (int) vendor_id);
210 			dpos += 4;
211 			dlen -= 4;
212 		}
213 
214 		wpa_hexdump(MSG_DEBUG, "EAP-TTLS: AVP data", dpos, dlen);
215 
216 		if (vendor_id == 0 && avp_code == RADIUS_ATTR_EAP_MESSAGE) {
217 			wpa_printf(MSG_DEBUG, "EAP-TTLS: AVP - EAP Message");
218 			if (parse->eap == NULL) {
219 				parse->eap = os_malloc(dlen);
220 				if (parse->eap == NULL) {
221 					wpa_printf(MSG_WARNING, "EAP-TTLS: "
222 						   "failed to allocate memory "
223 						   "for Phase 2 EAP data");
224 					goto fail;
225 				}
226 				os_memcpy(parse->eap, dpos, dlen);
227 				parse->eap_len = dlen;
228 			} else {
229 				u8 *neweap = os_realloc(parse->eap,
230 							parse->eap_len + dlen);
231 				if (neweap == NULL) {
232 					wpa_printf(MSG_WARNING, "EAP-TTLS: "
233 						   "failed to allocate memory "
234 						   "for Phase 2 EAP data");
235 					goto fail;
236 				}
237 				os_memcpy(neweap + parse->eap_len, dpos, dlen);
238 				parse->eap = neweap;
239 				parse->eap_len += dlen;
240 			}
241 		} else if (vendor_id == 0 &&
242 			   avp_code == RADIUS_ATTR_USER_NAME) {
243 			wpa_hexdump_ascii(MSG_DEBUG, "EAP-TTLS: User-Name",
244 					  dpos, dlen);
245 			parse->user_name = dpos;
246 			parse->user_name_len = dlen;
247 		} else if (vendor_id == 0 &&
248 			   avp_code == RADIUS_ATTR_USER_PASSWORD) {
249 			u8 *password = dpos;
250 			size_t password_len = dlen;
251 			while (password_len > 0 &&
252 			       password[password_len - 1] == '\0') {
253 				password_len--;
254 			}
255 			wpa_hexdump_ascii_key(MSG_DEBUG, "EAP-TTLS: "
256 					      "User-Password (PAP)",
257 					      password, password_len);
258 			parse->user_password = password;
259 			parse->user_password_len = password_len;
260 		} else if (vendor_id == 0 &&
261 			   avp_code == RADIUS_ATTR_CHAP_CHALLENGE) {
262 			wpa_hexdump(MSG_DEBUG,
263 				    "EAP-TTLS: CHAP-Challenge (CHAP)",
264 				    dpos, dlen);
265 			parse->chap_challenge = dpos;
266 			parse->chap_challenge_len = dlen;
267 		} else if (vendor_id == 0 &&
268 			   avp_code == RADIUS_ATTR_CHAP_PASSWORD) {
269 			wpa_hexdump(MSG_DEBUG,
270 				    "EAP-TTLS: CHAP-Password (CHAP)",
271 				    dpos, dlen);
272 			parse->chap_password = dpos;
273 			parse->chap_password_len = dlen;
274 		} else if (vendor_id == RADIUS_VENDOR_ID_MICROSOFT &&
275 			   avp_code == RADIUS_ATTR_MS_CHAP_CHALLENGE) {
276 			wpa_hexdump(MSG_DEBUG,
277 				    "EAP-TTLS: MS-CHAP-Challenge",
278 				    dpos, dlen);
279 			parse->mschap_challenge = dpos;
280 			parse->mschap_challenge_len = dlen;
281 		} else if (vendor_id == RADIUS_VENDOR_ID_MICROSOFT &&
282 			   avp_code == RADIUS_ATTR_MS_CHAP_RESPONSE) {
283 			wpa_hexdump(MSG_DEBUG,
284 				    "EAP-TTLS: MS-CHAP-Response (MSCHAP)",
285 				    dpos, dlen);
286 			parse->mschap_response = dpos;
287 			parse->mschap_response_len = dlen;
288 		} else if (vendor_id == RADIUS_VENDOR_ID_MICROSOFT &&
289 			   avp_code == RADIUS_ATTR_MS_CHAP2_RESPONSE) {
290 			wpa_hexdump(MSG_DEBUG,
291 				    "EAP-TTLS: MS-CHAP2-Response (MSCHAPV2)",
292 				    dpos, dlen);
293 			parse->mschap2_response = dpos;
294 			parse->mschap2_response_len = dlen;
295 		} else if (avp_flags & AVP_FLAGS_MANDATORY) {
296 			wpa_printf(MSG_WARNING, "EAP-TTLS: Unsupported "
297 				   "mandatory AVP code %d vendor_id %d - "
298 				   "dropped", (int) avp_code, (int) vendor_id);
299 			goto fail;
300 		} else {
301 			wpa_printf(MSG_DEBUG, "EAP-TTLS: Ignoring unsupported "
302 				   "AVP code %d vendor_id %d",
303 				   (int) avp_code, (int) vendor_id);
304 		}
305 
306 		pad = (4 - (avp_length & 3)) & 3;
307 		pos += avp_length + pad;
308 		left -= avp_length + pad;
309 	}
310 
311 	return 0;
312 
313 fail:
314 	os_free(parse->eap);
315 	parse->eap = NULL;
316 	return -1;
317 }
318 
319 
eap_ttls_implicit_challenge(struct eap_sm * sm,struct eap_ttls_data * data,size_t len)320 static u8 * eap_ttls_implicit_challenge(struct eap_sm *sm,
321 					struct eap_ttls_data *data, size_t len)
322 {
323 	struct tls_keys keys;
324 	u8 *challenge, *rnd;
325 
326 	if (data->ttls_version == 0) {
327 		return eap_server_tls_derive_key(sm, &data->ssl,
328 						 "ttls challenge", len);
329 	}
330 
331 	os_memset(&keys, 0, sizeof(keys));
332 	if (tls_connection_get_keys(sm->ssl_ctx, data->ssl.conn, &keys) ||
333 	    keys.client_random == NULL || keys.server_random == NULL ||
334 	    keys.inner_secret == NULL) {
335 		wpa_printf(MSG_INFO, "EAP-TTLS: Could not get inner secret, "
336 			   "client random, or server random to derive "
337 			   "implicit challenge");
338 		return NULL;
339 	}
340 
341 	rnd = os_malloc(keys.client_random_len + keys.server_random_len);
342 	challenge = os_malloc(len);
343 	if (rnd == NULL || challenge == NULL) {
344 		wpa_printf(MSG_INFO, "EAP-TTLS: No memory for implicit "
345 			   "challenge derivation");
346 		os_free(rnd);
347 		os_free(challenge);
348 		return NULL;
349 	}
350 	os_memcpy(rnd, keys.server_random, keys.server_random_len);
351 	os_memcpy(rnd + keys.server_random_len, keys.client_random,
352 		  keys.client_random_len);
353 
354 	if (tls_prf(keys.inner_secret, keys.inner_secret_len,
355 		    "inner application challenge", rnd,
356 		    keys.client_random_len + keys.server_random_len,
357 		    challenge, len)) {
358 		wpa_printf(MSG_DEBUG, "EAP-TTLS: Failed to derive implicit "
359 			   "challenge");
360 		os_free(rnd);
361 		os_free(challenge);
362 		return NULL;
363 	}
364 
365 	os_free(rnd);
366 
367 	wpa_hexdump_key(MSG_DEBUG, "EAP-TTLS: Derived implicit challenge",
368 			challenge, len);
369 
370 	return challenge;
371 }
372 
373 
eap_ttls_init(struct eap_sm * sm)374 static void * eap_ttls_init(struct eap_sm *sm)
375 {
376 	struct eap_ttls_data *data;
377 
378 	data = os_zalloc(sizeof(*data));
379 	if (data == NULL)
380 		return NULL;
381 	data->ttls_version = EAP_TTLS_VERSION;
382 	data->force_version = -1;
383 	if (sm->user && sm->user->force_version >= 0) {
384 		data->force_version = sm->user->force_version;
385 		wpa_printf(MSG_DEBUG, "EAP-TTLS: forcing version %d",
386 			   data->force_version);
387 		data->ttls_version = data->force_version;
388 	}
389 	data->state = START;
390 
391 	if (!(tls_capabilities(sm->ssl_ctx) & TLS_CAPABILITY_IA) &&
392 	    data->ttls_version > 0) {
393 		if (data->force_version > 0) {
394 			wpa_printf(MSG_INFO, "EAP-TTLS: Forced TTLSv%d and "
395 				   "TLS library does not support TLS/IA.",
396 				   data->force_version);
397 			eap_ttls_reset(sm, data);
398 			return NULL;
399 		}
400 		data->ttls_version = 0;
401 	}
402 
403 	if (eap_server_tls_ssl_init(sm, &data->ssl, 0)) {
404 		wpa_printf(MSG_INFO, "EAP-TTLS: Failed to initialize SSL.");
405 		eap_ttls_reset(sm, data);
406 		return NULL;
407 	}
408 
409 	return data;
410 }
411 
412 
eap_ttls_reset(struct eap_sm * sm,void * priv)413 static void eap_ttls_reset(struct eap_sm *sm, void *priv)
414 {
415 	struct eap_ttls_data *data = priv;
416 	if (data == NULL)
417 		return;
418 	if (data->phase2_priv && data->phase2_method)
419 		data->phase2_method->reset(sm, data->phase2_priv);
420 	eap_server_tls_ssl_deinit(sm, &data->ssl);
421 	wpabuf_free(data->pending_phase2_eap_resp);
422 	os_free(data);
423 }
424 
425 
eap_ttls_build_start(struct eap_sm * sm,struct eap_ttls_data * data,u8 id)426 static struct wpabuf * eap_ttls_build_start(struct eap_sm *sm,
427 					    struct eap_ttls_data *data, u8 id)
428 {
429 	struct wpabuf *req;
430 
431 	req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_TTLS, 1,
432 			    EAP_CODE_REQUEST, id);
433 	if (req == NULL) {
434 		wpa_printf(MSG_ERROR, "EAP-TTLS: Failed to allocate memory for"
435 			   " request");
436 		eap_ttls_state(data, FAILURE);
437 		return NULL;
438 	}
439 
440 	wpabuf_put_u8(req, EAP_TLS_FLAGS_START | data->ttls_version);
441 
442 	eap_ttls_state(data, PHASE1);
443 
444 	return req;
445 }
446 
447 
eap_ttls_build_phase2_eap_req(struct eap_sm * sm,struct eap_ttls_data * data,u8 id)448 static struct wpabuf * eap_ttls_build_phase2_eap_req(
449 	struct eap_sm *sm, struct eap_ttls_data *data, u8 id)
450 {
451 	struct wpabuf *buf, *encr_req;
452 	u8 *req;
453 	size_t req_len;
454 
455 
456 	buf = data->phase2_method->buildReq(sm, data->phase2_priv, id);
457 	if (buf == NULL)
458 		return NULL;
459 
460 	wpa_hexdump_buf_key(MSG_DEBUG,
461 			    "EAP-TTLS/EAP: Encapsulate Phase 2 data", buf);
462 
463 	buf = eap_ttls_avp_encapsulate(buf, RADIUS_ATTR_EAP_MESSAGE, 1);
464 	if (buf == NULL) {
465 		wpa_printf(MSG_DEBUG, "EAP-TTLS/EAP: Failed to encapsulate "
466 			   "packet");
467 		return NULL;
468 	}
469 
470 	req = wpabuf_mhead(buf);
471 	req_len = wpabuf_len(buf);
472 	wpa_hexdump_key(MSG_DEBUG, "EAP-TTLS/EAP: Encrypt encapsulated Phase "
473 			"2 data", req, req_len);
474 
475 	encr_req = eap_server_tls_encrypt(sm, &data->ssl, req, req_len);
476 	wpabuf_free(buf);
477 
478 	return encr_req;
479 }
480 
481 
eap_ttls_build_phase2_mschapv2(struct eap_sm * sm,struct eap_ttls_data * data)482 static struct wpabuf * eap_ttls_build_phase2_mschapv2(
483 	struct eap_sm *sm, struct eap_ttls_data *data)
484 {
485 	struct wpabuf *encr_req;
486 	u8 *req, *pos, *end;
487 	int ret;
488 	size_t req_len;
489 
490 	pos = req = os_malloc(100);
491 	if (req == NULL)
492 		return NULL;
493 	end = req + 100;
494 
495 	if (data->mschapv2_resp_ok) {
496 		pos = eap_ttls_avp_hdr(pos, RADIUS_ATTR_MS_CHAP2_SUCCESS,
497 				       RADIUS_VENDOR_ID_MICROSOFT, 1, 43);
498 		*pos++ = data->mschapv2_ident;
499 		ret = os_snprintf((char *) pos, end - pos, "S=");
500 		if (ret >= 0 && ret < end - pos)
501 			pos += ret;
502 		pos += wpa_snprintf_hex_uppercase(
503 			(char *) pos, end - pos, data->mschapv2_auth_response,
504 			sizeof(data->mschapv2_auth_response));
505 	} else {
506 		pos = eap_ttls_avp_hdr(pos, RADIUS_ATTR_MS_CHAP_ERROR,
507 				       RADIUS_VENDOR_ID_MICROSOFT, 1, 6);
508 		os_memcpy(pos, "Failed", 6);
509 		pos += 6;
510 		AVP_PAD(req, pos);
511 	}
512 
513 	req_len = pos - req;
514 	wpa_hexdump_key(MSG_DEBUG, "EAP-TTLS/MSCHAPV2: Encrypting Phase 2 "
515 			"data", req, req_len);
516 
517 	encr_req = eap_server_tls_encrypt(sm, &data->ssl, req, req_len);
518 	os_free(req);
519 
520 	return encr_req;
521 }
522 
523 
eap_ttls_build_phase_finished(struct eap_sm * sm,struct eap_ttls_data * data,int final)524 static struct wpabuf * eap_ttls_build_phase_finished(
525 	struct eap_sm *sm, struct eap_ttls_data *data, int final)
526 {
527 	int len;
528 	struct wpabuf *req;
529 	const int max_len = 300;
530 
531 	req = wpabuf_alloc(max_len);
532 	if (req == NULL)
533 		return NULL;
534 
535 	len = tls_connection_ia_send_phase_finished(sm->ssl_ctx,
536 						    data->ssl.conn, final,
537 						    wpabuf_mhead(req),
538 						    max_len);
539 	if (len < 0) {
540 		wpabuf_free(req);
541 		return NULL;
542 	}
543 	wpabuf_put(req, len);
544 
545 	return req;
546 }
547 
548 
eap_ttls_buildReq(struct eap_sm * sm,void * priv,u8 id)549 static struct wpabuf * eap_ttls_buildReq(struct eap_sm *sm, void *priv, u8 id)
550 {
551 	struct eap_ttls_data *data = priv;
552 
553 	if (data->ssl.state == FRAG_ACK) {
554 		return eap_server_tls_build_ack(id, EAP_TYPE_TTLS,
555 						data->ttls_version);
556 	}
557 
558 	if (data->ssl.state == WAIT_FRAG_ACK) {
559 		return eap_server_tls_build_msg(&data->ssl, EAP_TYPE_TTLS,
560 						data->ttls_version, id);
561 	}
562 
563 	switch (data->state) {
564 	case START:
565 		return eap_ttls_build_start(sm, data, id);
566 	case PHASE1:
567 		if (tls_connection_established(sm->ssl_ctx, data->ssl.conn)) {
568 			wpa_printf(MSG_DEBUG, "EAP-TTLS: Phase1 done, "
569 				   "starting Phase2");
570 			eap_ttls_state(data, PHASE2_START);
571 		}
572 		break;
573 	case PHASE2_METHOD:
574 		wpabuf_free(data->ssl.out_buf);
575 		data->ssl.out_used = 0;
576 		data->ssl.out_buf = eap_ttls_build_phase2_eap_req(sm, data,
577 								  id);
578 		break;
579 	case PHASE2_MSCHAPV2_RESP:
580 		wpabuf_free(data->ssl.out_buf);
581 		data->ssl.out_used = 0;
582 		data->ssl.out_buf = eap_ttls_build_phase2_mschapv2(sm, data);
583 		break;
584 	case PHASE_FINISHED:
585 		wpabuf_free(data->ssl.out_buf);
586 		data->ssl.out_used = 0;
587 		data->ssl.out_buf = eap_ttls_build_phase_finished(sm, data, 1);
588 		break;
589 	default:
590 		wpa_printf(MSG_DEBUG, "EAP-TTLS: %s - unexpected state %d",
591 			   __func__, data->state);
592 		return NULL;
593 	}
594 
595 	return eap_server_tls_build_msg(&data->ssl, EAP_TYPE_TTLS,
596 					data->ttls_version, id);
597 }
598 
599 
eap_ttls_check(struct eap_sm * sm,void * priv,struct wpabuf * respData)600 static Boolean eap_ttls_check(struct eap_sm *sm, void *priv,
601 			      struct wpabuf *respData)
602 {
603 	const u8 *pos;
604 	size_t len;
605 
606 	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_TTLS, respData, &len);
607 	if (pos == NULL || len < 1) {
608 		wpa_printf(MSG_INFO, "EAP-TTLS: Invalid frame");
609 		return TRUE;
610 	}
611 
612 	return FALSE;
613 }
614 
615 
eap_ttls_ia_permute_inner_secret(struct eap_sm * sm,struct eap_ttls_data * data,const u8 * key,size_t key_len)616 static int eap_ttls_ia_permute_inner_secret(struct eap_sm *sm,
617 					    struct eap_ttls_data *data,
618 					    const u8 *key, size_t key_len)
619 {
620 	u8 *buf;
621 	size_t buf_len;
622 	int ret;
623 
624 	if (key) {
625 		buf_len = 2 + key_len;
626 		buf = os_malloc(buf_len);
627 		if (buf == NULL)
628 			return -1;
629 		WPA_PUT_BE16(buf, key_len);
630 		os_memcpy(buf + 2, key, key_len);
631 	} else {
632 		buf = NULL;
633 		buf_len = 0;
634 	}
635 
636 	wpa_hexdump_key(MSG_DEBUG, "EAP-TTLS: Session keys for TLS/IA inner "
637 			"secret permutation", buf, buf_len);
638 	ret = tls_connection_ia_permute_inner_secret(sm->ssl_ctx,
639 						     data->ssl.conn,
640 						     buf, buf_len);
641 	os_free(buf);
642 
643 	return ret;
644 }
645 
646 
eap_ttls_process_phase2_pap(struct eap_sm * sm,struct eap_ttls_data * data,const u8 * user_password,size_t user_password_len)647 static void eap_ttls_process_phase2_pap(struct eap_sm *sm,
648 					struct eap_ttls_data *data,
649 					const u8 *user_password,
650 					size_t user_password_len)
651 {
652 	if (!sm->user || !sm->user->password || sm->user->password_hash ||
653 	    !(sm->user->ttls_auth & EAP_TTLS_AUTH_PAP)) {
654 		wpa_printf(MSG_DEBUG, "EAP-TTLS/PAP: No plaintext user "
655 			   "password configured");
656 		eap_ttls_state(data, FAILURE);
657 		return;
658 	}
659 
660 	if (sm->user->password_len != user_password_len ||
661 	    os_memcmp(sm->user->password, user_password, user_password_len) !=
662 	    0) {
663 		wpa_printf(MSG_DEBUG, "EAP-TTLS/PAP: Invalid user password");
664 		eap_ttls_state(data, FAILURE);
665 		return;
666 	}
667 
668 	wpa_printf(MSG_DEBUG, "EAP-TTLS/PAP: Correct user password");
669 	eap_ttls_state(data, data->ttls_version > 0 ? PHASE_FINISHED :
670 		       SUCCESS);
671 }
672 
673 
eap_ttls_process_phase2_chap(struct eap_sm * sm,struct eap_ttls_data * data,const u8 * challenge,size_t challenge_len,const u8 * password,size_t password_len)674 static void eap_ttls_process_phase2_chap(struct eap_sm *sm,
675 					 struct eap_ttls_data *data,
676 					 const u8 *challenge,
677 					 size_t challenge_len,
678 					 const u8 *password,
679 					 size_t password_len)
680 {
681 	u8 *chal, hash[CHAP_MD5_LEN];
682 
683 	if (challenge == NULL || password == NULL ||
684 	    challenge_len != EAP_TTLS_CHAP_CHALLENGE_LEN ||
685 	    password_len != 1 + EAP_TTLS_CHAP_PASSWORD_LEN) {
686 		wpa_printf(MSG_DEBUG, "EAP-TTLS/CHAP: Invalid CHAP attributes "
687 			   "(challenge len %lu password len %lu)",
688 			   (unsigned long) challenge_len,
689 			   (unsigned long) password_len);
690 		eap_ttls_state(data, FAILURE);
691 		return;
692 	}
693 
694 	if (!sm->user || !sm->user->password || sm->user->password_hash ||
695 	    !(sm->user->ttls_auth & EAP_TTLS_AUTH_CHAP)) {
696 		wpa_printf(MSG_DEBUG, "EAP-TTLS/CHAP: No plaintext user "
697 			   "password configured");
698 		eap_ttls_state(data, FAILURE);
699 		return;
700 	}
701 
702 	chal = eap_ttls_implicit_challenge(sm, data,
703 					   EAP_TTLS_CHAP_CHALLENGE_LEN + 1);
704 	if (chal == NULL) {
705 		wpa_printf(MSG_DEBUG, "EAP-TTLS/CHAP: Failed to generate "
706 			   "challenge from TLS data");
707 		eap_ttls_state(data, FAILURE);
708 		return;
709 	}
710 
711 	if (os_memcmp(challenge, chal, EAP_TTLS_CHAP_CHALLENGE_LEN) != 0 ||
712 	    password[0] != chal[EAP_TTLS_CHAP_CHALLENGE_LEN]) {
713 		wpa_printf(MSG_DEBUG, "EAP-TTLS/CHAP: Challenge mismatch");
714 		os_free(chal);
715 		eap_ttls_state(data, FAILURE);
716 		return;
717 	}
718 	os_free(chal);
719 
720 	/* MD5(Ident + Password + Challenge) */
721 	chap_md5(password[0], sm->user->password, sm->user->password_len,
722 		 challenge, challenge_len, hash);
723 
724 	if (os_memcmp(hash, password + 1, EAP_TTLS_CHAP_PASSWORD_LEN) == 0) {
725 		wpa_printf(MSG_DEBUG, "EAP-TTLS/CHAP: Correct user password");
726 		eap_ttls_state(data, data->ttls_version > 0 ? PHASE_FINISHED :
727 			       SUCCESS);
728 	} else {
729 		wpa_printf(MSG_DEBUG, "EAP-TTLS/CHAP: Invalid user password");
730 		eap_ttls_state(data, FAILURE);
731 	}
732 }
733 
734 
eap_ttls_process_phase2_mschap(struct eap_sm * sm,struct eap_ttls_data * data,u8 * challenge,size_t challenge_len,u8 * response,size_t response_len)735 static void eap_ttls_process_phase2_mschap(struct eap_sm *sm,
736 					   struct eap_ttls_data *data,
737 					   u8 *challenge, size_t challenge_len,
738 					   u8 *response, size_t response_len)
739 {
740 	u8 *chal, nt_response[24];
741 
742 	if (challenge == NULL || response == NULL ||
743 	    challenge_len != EAP_TTLS_MSCHAP_CHALLENGE_LEN ||
744 	    response_len != EAP_TTLS_MSCHAP_RESPONSE_LEN) {
745 		wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAP: Invalid MS-CHAP "
746 			   "attributes (challenge len %lu response len %lu)",
747 			   (unsigned long) challenge_len,
748 			   (unsigned long) response_len);
749 		eap_ttls_state(data, FAILURE);
750 		return;
751 	}
752 
753 	if (!sm->user || !sm->user->password ||
754 	    !(sm->user->ttls_auth & EAP_TTLS_AUTH_MSCHAP)) {
755 		wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAP: No user password "
756 			   "configured");
757 		eap_ttls_state(data, FAILURE);
758 		return;
759 	}
760 
761 	chal = eap_ttls_implicit_challenge(sm, data,
762 					   EAP_TTLS_MSCHAP_CHALLENGE_LEN + 1);
763 	if (chal == NULL) {
764 		wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAP: Failed to generate "
765 			   "challenge from TLS data");
766 		eap_ttls_state(data, FAILURE);
767 		return;
768 	}
769 
770 	if (os_memcmp(challenge, chal, EAP_TTLS_MSCHAP_CHALLENGE_LEN) != 0 ||
771 	    response[0] != chal[EAP_TTLS_MSCHAP_CHALLENGE_LEN]) {
772 		wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAP: Challenge mismatch");
773 		os_free(chal);
774 		eap_ttls_state(data, FAILURE);
775 		return;
776 	}
777 	os_free(chal);
778 
779 	if (sm->user->password_hash)
780 		challenge_response(challenge, sm->user->password, nt_response);
781 	else
782 		nt_challenge_response(challenge, sm->user->password,
783 				      sm->user->password_len, nt_response);
784 
785 	if (os_memcmp(nt_response, response + 2 + 24, 24) == 0) {
786 		wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAP: Correct response");
787 		eap_ttls_state(data, data->ttls_version > 0 ? PHASE_FINISHED :
788 			       SUCCESS);
789 	} else {
790 		wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAP: Invalid NT-Response");
791 		wpa_hexdump(MSG_MSGDUMP, "EAP-TTLS/MSCHAP: Received",
792 			    response + 2 + 24, 24);
793 		wpa_hexdump(MSG_MSGDUMP, "EAP-TTLS/MSCHAP: Expected",
794 			    nt_response, 24);
795 		eap_ttls_state(data, FAILURE);
796 	}
797 }
798 
799 
eap_ttls_process_phase2_mschapv2(struct eap_sm * sm,struct eap_ttls_data * data,u8 * challenge,size_t challenge_len,u8 * response,size_t response_len)800 static void eap_ttls_process_phase2_mschapv2(struct eap_sm *sm,
801 					     struct eap_ttls_data *data,
802 					     u8 *challenge,
803 					     size_t challenge_len,
804 					     u8 *response, size_t response_len)
805 {
806 	u8 *chal, *username, nt_response[24], *rx_resp, *peer_challenge,
807 		*auth_challenge;
808 	size_t username_len, i;
809 
810 	if (challenge == NULL || response == NULL ||
811 	    challenge_len != EAP_TTLS_MSCHAPV2_CHALLENGE_LEN ||
812 	    response_len != EAP_TTLS_MSCHAPV2_RESPONSE_LEN) {
813 		wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAPV2: Invalid MS-CHAP2 "
814 			   "attributes (challenge len %lu response len %lu)",
815 			   (unsigned long) challenge_len,
816 			   (unsigned long) response_len);
817 		eap_ttls_state(data, FAILURE);
818 		return;
819 	}
820 
821 	if (!sm->user || !sm->user->password ||
822 	    !(sm->user->ttls_auth & EAP_TTLS_AUTH_MSCHAPV2)) {
823 		wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAPV2: No user password "
824 			   "configured");
825 		eap_ttls_state(data, FAILURE);
826 		return;
827 	}
828 
829 	/* MSCHAPv2 does not include optional domain name in the
830 	 * challenge-response calculation, so remove domain prefix
831 	 * (if present). */
832 	username = sm->identity;
833 	username_len = sm->identity_len;
834 	for (i = 0; i < username_len; i++) {
835 		if (username[i] == '\\') {
836 			username_len -= i + 1;
837 			username += i + 1;
838 			break;
839 		}
840 	}
841 
842 	chal = eap_ttls_implicit_challenge(
843 		sm, data, EAP_TTLS_MSCHAPV2_CHALLENGE_LEN + 1);
844 	if (chal == NULL) {
845 		wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAPV2: Failed to generate "
846 			   "challenge from TLS data");
847 		eap_ttls_state(data, FAILURE);
848 		return;
849 	}
850 
851 	if (os_memcmp(challenge, chal, EAP_TTLS_MSCHAPV2_CHALLENGE_LEN) != 0 ||
852 	    response[0] != chal[EAP_TTLS_MSCHAPV2_CHALLENGE_LEN]) {
853 		wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAPV2: Challenge mismatch");
854 		os_free(chal);
855 		eap_ttls_state(data, FAILURE);
856 		return;
857 	}
858 	os_free(chal);
859 
860 	auth_challenge = challenge;
861 	peer_challenge = response + 2;
862 
863 	wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-TTLS/MSCHAPV2: User",
864 			  username, username_len);
865 	wpa_hexdump(MSG_MSGDUMP, "EAP-TTLS/MSCHAPV2: auth_challenge",
866 		    auth_challenge, EAP_TTLS_MSCHAPV2_CHALLENGE_LEN);
867 	wpa_hexdump(MSG_MSGDUMP, "EAP-TTLS/MSCHAPV2: peer_challenge",
868 		    peer_challenge, EAP_TTLS_MSCHAPV2_CHALLENGE_LEN);
869 
870 	if (sm->user->password_hash) {
871 		generate_nt_response_pwhash(auth_challenge, peer_challenge,
872 					    username, username_len,
873 					    sm->user->password,
874 					    nt_response);
875 	} else {
876 		generate_nt_response(auth_challenge, peer_challenge,
877 				     username, username_len,
878 				     sm->user->password,
879 				     sm->user->password_len,
880 				     nt_response);
881 	}
882 
883 	rx_resp = response + 2 + EAP_TTLS_MSCHAPV2_CHALLENGE_LEN + 8;
884 	if (os_memcmp(nt_response, rx_resp, 24) == 0) {
885 		wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAPV2: Correct "
886 			   "NT-Response");
887 		data->mschapv2_resp_ok = 1;
888 		if (data->ttls_version > 0) {
889 			const u8 *pw_hash;
890 			u8 pw_hash_buf[16], pw_hash_hash[16], master_key[16];
891 			u8 session_key[2 * MSCHAPV2_KEY_LEN];
892 
893 			if (sm->user->password_hash)
894 				pw_hash = sm->user->password;
895 			else {
896 				nt_password_hash(sm->user->password,
897 						 sm->user->password_len,
898 						 pw_hash_buf);
899 				pw_hash = pw_hash_buf;
900 			}
901 			hash_nt_password_hash(pw_hash, pw_hash_hash);
902 			get_master_key(pw_hash_hash, nt_response, master_key);
903 			get_asymetric_start_key(master_key, session_key,
904 						MSCHAPV2_KEY_LEN, 0, 0);
905 			get_asymetric_start_key(master_key,
906 						session_key + MSCHAPV2_KEY_LEN,
907 						MSCHAPV2_KEY_LEN, 1, 0);
908 			eap_ttls_ia_permute_inner_secret(sm, data,
909 							 session_key,
910 							 sizeof(session_key));
911 		}
912 
913 		if (sm->user->password_hash) {
914 			generate_authenticator_response_pwhash(
915 				sm->user->password,
916 				peer_challenge, auth_challenge,
917 				username, username_len, nt_response,
918 				data->mschapv2_auth_response);
919 		} else {
920 			generate_authenticator_response(
921 				sm->user->password, sm->user->password_len,
922 				peer_challenge, auth_challenge,
923 				username, username_len, nt_response,
924 				data->mschapv2_auth_response);
925 		}
926 	} else {
927 		wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAPV2: Invalid "
928 			   "NT-Response");
929 		wpa_hexdump(MSG_MSGDUMP, "EAP-TTLS/MSCHAPV2: Received",
930 			    rx_resp, 24);
931 		wpa_hexdump(MSG_MSGDUMP, "EAP-TTLS/MSCHAPV2: Expected",
932 			    nt_response, 24);
933 		data->mschapv2_resp_ok = 0;
934 	}
935 	eap_ttls_state(data, PHASE2_MSCHAPV2_RESP);
936 	data->mschapv2_ident = response[0];
937 }
938 
939 
eap_ttls_phase2_eap_init(struct eap_sm * sm,struct eap_ttls_data * data,EapType eap_type)940 static int eap_ttls_phase2_eap_init(struct eap_sm *sm,
941 				    struct eap_ttls_data *data,
942 				    EapType eap_type)
943 {
944 	if (data->phase2_priv && data->phase2_method) {
945 		data->phase2_method->reset(sm, data->phase2_priv);
946 		data->phase2_method = NULL;
947 		data->phase2_priv = NULL;
948 	}
949 	data->phase2_method = eap_server_get_eap_method(EAP_VENDOR_IETF,
950 							eap_type);
951 	if (!data->phase2_method)
952 		return -1;
953 
954 	sm->init_phase2 = 1;
955 	data->phase2_priv = data->phase2_method->init(sm);
956 	sm->init_phase2 = 0;
957 	return data->phase2_priv == NULL ? -1 : 0;
958 }
959 
960 
eap_ttls_process_phase2_eap_response(struct eap_sm * sm,struct eap_ttls_data * data,u8 * in_data,size_t in_len)961 static void eap_ttls_process_phase2_eap_response(struct eap_sm *sm,
962 						 struct eap_ttls_data *data,
963 						 u8 *in_data, size_t in_len)
964 {
965 	u8 next_type = EAP_TYPE_NONE;
966 	struct eap_hdr *hdr;
967 	u8 *pos;
968 	size_t left;
969 	struct wpabuf buf;
970 	const struct eap_method *m = data->phase2_method;
971 	void *priv = data->phase2_priv;
972 
973 	if (priv == NULL) {
974 		wpa_printf(MSG_DEBUG, "EAP-TTLS/EAP: %s - Phase2 not "
975 			   "initialized?!", __func__);
976 		return;
977 	}
978 
979 	hdr = (struct eap_hdr *) in_data;
980 	pos = (u8 *) (hdr + 1);
981 
982 	if (in_len > sizeof(*hdr) && *pos == EAP_TYPE_NAK) {
983 		left = in_len - sizeof(*hdr);
984 		wpa_hexdump(MSG_DEBUG, "EAP-TTLS/EAP: Phase2 type Nak'ed; "
985 			    "allowed types", pos + 1, left - 1);
986 		eap_sm_process_nak(sm, pos + 1, left - 1);
987 		if (sm->user && sm->user_eap_method_index < EAP_MAX_METHODS &&
988 		    sm->user->methods[sm->user_eap_method_index].method !=
989 		    EAP_TYPE_NONE) {
990 			next_type = sm->user->methods[
991 				sm->user_eap_method_index++].method;
992 			wpa_printf(MSG_DEBUG, "EAP-TTLS: try EAP type %d",
993 				   next_type);
994 			if (eap_ttls_phase2_eap_init(sm, data, next_type)) {
995 				wpa_printf(MSG_DEBUG, "EAP-TTLS: Failed to "
996 					   "initialize EAP type %d",
997 					   next_type);
998 				eap_ttls_state(data, FAILURE);
999 				return;
1000 			}
1001 		} else {
1002 			eap_ttls_state(data, FAILURE);
1003 		}
1004 		return;
1005 	}
1006 
1007 	wpabuf_set(&buf, in_data, in_len);
1008 
1009 	if (m->check(sm, priv, &buf)) {
1010 		wpa_printf(MSG_DEBUG, "EAP-TTLS/EAP: Phase2 check() asked to "
1011 			   "ignore the packet");
1012 		return;
1013 	}
1014 
1015 	m->process(sm, priv, &buf);
1016 
1017 	if (sm->method_pending == METHOD_PENDING_WAIT) {
1018 		wpa_printf(MSG_DEBUG, "EAP-TTLS/EAP: Phase2 method is in "
1019 			   "pending wait state - save decrypted response");
1020 		wpabuf_free(data->pending_phase2_eap_resp);
1021 		data->pending_phase2_eap_resp = wpabuf_dup(&buf);
1022 	}
1023 
1024 	if (!m->isDone(sm, priv))
1025 		return;
1026 
1027 	if (!m->isSuccess(sm, priv)) {
1028 		wpa_printf(MSG_DEBUG, "EAP-TTLS/EAP: Phase2 method failed");
1029 		eap_ttls_state(data, FAILURE);
1030 		return;
1031 	}
1032 
1033 	switch (data->state) {
1034 	case PHASE2_START:
1035 		if (eap_user_get(sm, sm->identity, sm->identity_len, 1) != 0) {
1036 			wpa_hexdump_ascii(MSG_DEBUG, "EAP_TTLS: Phase2 "
1037 					  "Identity not found in the user "
1038 					  "database",
1039 					  sm->identity, sm->identity_len);
1040 			eap_ttls_state(data, FAILURE);
1041 			break;
1042 		}
1043 
1044 		eap_ttls_state(data, PHASE2_METHOD);
1045 		next_type = sm->user->methods[0].method;
1046 		sm->user_eap_method_index = 1;
1047 		wpa_printf(MSG_DEBUG, "EAP-TTLS: try EAP type %d", next_type);
1048 		if (eap_ttls_phase2_eap_init(sm, data, next_type)) {
1049 			wpa_printf(MSG_DEBUG, "EAP-TTLS: Failed to initialize "
1050 				   "EAP type %d", next_type);
1051 			eap_ttls_state(data, FAILURE);
1052 		}
1053 		break;
1054 	case PHASE2_METHOD:
1055 		if (data->ttls_version > 0) {
1056 			if (m->getKey) {
1057 				u8 *key;
1058 				size_t key_len;
1059 				key = m->getKey(sm, priv, &key_len);
1060 				eap_ttls_ia_permute_inner_secret(sm, data,
1061 								 key, key_len);
1062 			}
1063 			eap_ttls_state(data, PHASE_FINISHED);
1064 		} else
1065 			eap_ttls_state(data, SUCCESS);
1066 		break;
1067 	case FAILURE:
1068 		break;
1069 	default:
1070 		wpa_printf(MSG_DEBUG, "EAP-TTLS: %s - unexpected state %d",
1071 			   __func__, data->state);
1072 		break;
1073 	}
1074 }
1075 
1076 
eap_ttls_process_phase2_eap(struct eap_sm * sm,struct eap_ttls_data * data,const u8 * eap,size_t eap_len)1077 static void eap_ttls_process_phase2_eap(struct eap_sm *sm,
1078 					struct eap_ttls_data *data,
1079 					const u8 *eap, size_t eap_len)
1080 {
1081 	struct eap_hdr *hdr;
1082 	size_t len;
1083 
1084 	if (data->state == PHASE2_START) {
1085 		wpa_printf(MSG_DEBUG, "EAP-TTLS/EAP: initializing Phase 2");
1086 		if (eap_ttls_phase2_eap_init(sm, data, EAP_TYPE_IDENTITY) < 0)
1087 		{
1088 			wpa_printf(MSG_DEBUG, "EAP-TTLS/EAP: failed to "
1089 				   "initialize EAP-Identity");
1090 			return;
1091 		}
1092 	}
1093 
1094 	if (eap_len < sizeof(*hdr)) {
1095 		wpa_printf(MSG_DEBUG, "EAP-TTLS/EAP: too short Phase 2 EAP "
1096 			   "packet (len=%lu)", (unsigned long) eap_len);
1097 		return;
1098 	}
1099 
1100 	hdr = (struct eap_hdr *) eap;
1101 	len = be_to_host16(hdr->length);
1102 	wpa_printf(MSG_DEBUG, "EAP-TTLS/EAP: received Phase 2 EAP: code=%d "
1103 		   "identifier=%d length=%lu", hdr->code, hdr->identifier,
1104 		   (unsigned long) len);
1105 	if (len > eap_len) {
1106 		wpa_printf(MSG_INFO, "EAP-TTLS/EAP: Length mismatch in Phase 2"
1107 			   " EAP frame (hdr len=%lu, data len in AVP=%lu)",
1108 			   (unsigned long) len, (unsigned long) eap_len);
1109 		return;
1110 	}
1111 
1112 	switch (hdr->code) {
1113 	case EAP_CODE_RESPONSE:
1114 		eap_ttls_process_phase2_eap_response(sm, data, (u8 *) hdr,
1115 						     len);
1116 		break;
1117 	default:
1118 		wpa_printf(MSG_INFO, "EAP-TTLS/EAP: Unexpected code=%d in "
1119 			   "Phase 2 EAP header", hdr->code);
1120 		break;
1121 	}
1122 }
1123 
1124 
eap_ttls_process_phase2(struct eap_sm * sm,struct eap_ttls_data * data,struct wpabuf * in_buf)1125 static void eap_ttls_process_phase2(struct eap_sm *sm,
1126 				    struct eap_ttls_data *data,
1127 				    struct wpabuf *in_buf)
1128 {
1129 	u8 *in_decrypted;
1130 	int len_decrypted;
1131 	struct eap_ttls_avp parse;
1132 	size_t buf_len;
1133 	u8 *in_data;
1134 	size_t in_len;
1135 
1136 	in_data = wpabuf_mhead(in_buf);
1137 	in_len = wpabuf_len(in_buf);
1138 
1139 	wpa_printf(MSG_DEBUG, "EAP-TTLS: received %lu bytes encrypted data for"
1140 		   " Phase 2", (unsigned long) in_len);
1141 
1142 	if (data->pending_phase2_eap_resp) {
1143 		wpa_printf(MSG_DEBUG, "EAP-TTLS: Pending Phase 2 EAP response "
1144 			   "- skip decryption and use old data");
1145 		eap_ttls_process_phase2_eap(
1146 			sm, data, wpabuf_head(data->pending_phase2_eap_resp),
1147 			wpabuf_len(data->pending_phase2_eap_resp));
1148 		wpabuf_free(data->pending_phase2_eap_resp);
1149 		data->pending_phase2_eap_resp = NULL;
1150 		return;
1151 	}
1152 
1153 	buf_len = in_len;
1154 	/*
1155 	 * Even though we try to disable TLS compression, it is possible that
1156 	 * this cannot be done with all TLS libraries. Add extra buffer space
1157 	 * to handle the possibility of the decrypted data being longer than
1158 	 * input data.
1159 	 */
1160 	buf_len += 500;
1161 	buf_len *= 3;
1162 	in_decrypted = os_malloc(buf_len);
1163 	if (in_decrypted == NULL) {
1164 		wpa_printf(MSG_WARNING, "EAP-TTLS: failed to allocate memory "
1165 			   "for decryption");
1166 		return;
1167 	}
1168 
1169 	len_decrypted = tls_connection_decrypt(sm->ssl_ctx, data->ssl.conn,
1170 					       in_data, in_len,
1171 					       in_decrypted, buf_len);
1172 	if (len_decrypted < 0) {
1173 		wpa_printf(MSG_INFO, "EAP-TTLS: Failed to decrypt Phase 2 "
1174 			   "data");
1175 		os_free(in_decrypted);
1176 		eap_ttls_state(data, FAILURE);
1177 		return;
1178 	}
1179 
1180 	if (data->state == PHASE_FINISHED) {
1181 		if (len_decrypted == 0 &&
1182 		    tls_connection_ia_final_phase_finished(sm->ssl_ctx,
1183 							   data->ssl.conn)) {
1184 			wpa_printf(MSG_DEBUG, "EAP-TTLS: FinalPhaseFinished "
1185 				   "received");
1186 			eap_ttls_state(data, SUCCESS);
1187 		} else {
1188 			wpa_printf(MSG_INFO, "EAP-TTLS: Did not receive valid "
1189 				   "FinalPhaseFinished");
1190 			eap_ttls_state(data, FAILURE);
1191 		}
1192 
1193 		os_free(in_decrypted);
1194 		return;
1195 	}
1196 
1197 	wpa_hexdump_key(MSG_DEBUG, "EAP-TTLS: Decrypted Phase 2 EAP",
1198 			in_decrypted, len_decrypted);
1199 
1200 	if (eap_ttls_avp_parse(in_decrypted, len_decrypted, &parse) < 0) {
1201 		wpa_printf(MSG_DEBUG, "EAP-TTLS: Failed to parse AVPs");
1202 		os_free(in_decrypted);
1203 		eap_ttls_state(data, FAILURE);
1204 		return;
1205 	}
1206 
1207 	if (parse.user_name) {
1208 		os_free(sm->identity);
1209 		sm->identity = os_malloc(parse.user_name_len);
1210 		if (sm->identity) {
1211 			os_memcpy(sm->identity, parse.user_name,
1212 				  parse.user_name_len);
1213 			sm->identity_len = parse.user_name_len;
1214 		}
1215 		if (eap_user_get(sm, parse.user_name, parse.user_name_len, 1)
1216 		    != 0) {
1217 			wpa_printf(MSG_DEBUG, "EAP-TTLS: Phase2 Identity not "
1218 				   "found in the user database");
1219 			eap_ttls_state(data, FAILURE);
1220 			goto done;
1221 		}
1222 	}
1223 
1224 #ifdef EAP_TNC
1225 	if (data->tnc_started && parse.eap == NULL) {
1226 		wpa_printf(MSG_DEBUG, "EAP-TTLS: TNC started but no EAP "
1227 			   "response from peer");
1228 		eap_ttls_state(data, FAILURE);
1229 		goto done;
1230 	}
1231 #endif /* EAP_TNC */
1232 
1233 	if (parse.eap) {
1234 		eap_ttls_process_phase2_eap(sm, data, parse.eap,
1235 					    parse.eap_len);
1236 	} else if (parse.user_password) {
1237 		eap_ttls_process_phase2_pap(sm, data, parse.user_password,
1238 					    parse.user_password_len);
1239 	} else if (parse.chap_password) {
1240 		eap_ttls_process_phase2_chap(sm, data,
1241 					     parse.chap_challenge,
1242 					     parse.chap_challenge_len,
1243 					     parse.chap_password,
1244 					     parse.chap_password_len);
1245 	} else if (parse.mschap_response) {
1246 		eap_ttls_process_phase2_mschap(sm, data,
1247 					       parse.mschap_challenge,
1248 					       parse.mschap_challenge_len,
1249 					       parse.mschap_response,
1250 					       parse.mschap_response_len);
1251 	} else if (parse.mschap2_response) {
1252 		eap_ttls_process_phase2_mschapv2(sm, data,
1253 						 parse.mschap_challenge,
1254 						 parse.mschap_challenge_len,
1255 						 parse.mschap2_response,
1256 						 parse.mschap2_response_len);
1257 	}
1258 
1259 done:
1260 	os_free(in_decrypted);
1261 	os_free(parse.eap);
1262 }
1263 
1264 
eap_ttls_start_tnc(struct eap_sm * sm,struct eap_ttls_data * data)1265 static void eap_ttls_start_tnc(struct eap_sm *sm, struct eap_ttls_data *data)
1266 {
1267 #ifdef EAP_TNC
1268 	if (!sm->tnc || data->state != SUCCESS || data->tnc_started)
1269 		return;
1270 
1271 	wpa_printf(MSG_DEBUG, "EAP-TTLS: Initialize TNC");
1272 	if (eap_ttls_phase2_eap_init(sm, data, EAP_TYPE_TNC)) {
1273 		wpa_printf(MSG_DEBUG, "EAP-TTLS: Failed to initialize TNC");
1274 		eap_ttls_state(data, FAILURE);
1275 		return;
1276 	}
1277 
1278 	data->tnc_started = 1;
1279 	eap_ttls_state(data, PHASE2_METHOD);
1280 #endif /* EAP_TNC */
1281 }
1282 
1283 
eap_ttls_process_version(struct eap_sm * sm,void * priv,int peer_version)1284 static int eap_ttls_process_version(struct eap_sm *sm, void *priv,
1285 				    int peer_version)
1286 {
1287 	struct eap_ttls_data *data = priv;
1288 	if (peer_version < data->ttls_version) {
1289 		wpa_printf(MSG_DEBUG, "EAP-TTLS: peer ver=%d, own ver=%d; "
1290 			   "use version %d",
1291 			   peer_version, data->ttls_version, peer_version);
1292 		data->ttls_version = peer_version;
1293 	}
1294 
1295 	if (data->ttls_version > 0 && !data->tls_ia_configured) {
1296 		if (tls_connection_set_ia(sm->ssl_ctx, data->ssl.conn, 1)) {
1297 			wpa_printf(MSG_INFO, "EAP-TTLS: Failed to enable "
1298 				   "TLS/IA");
1299 			return -1;
1300 		}
1301 		data->tls_ia_configured = 1;
1302 	}
1303 
1304 	return 0;
1305 }
1306 
1307 
eap_ttls_process_msg(struct eap_sm * sm,void * priv,const struct wpabuf * respData)1308 static void eap_ttls_process_msg(struct eap_sm *sm, void *priv,
1309 				 const struct wpabuf *respData)
1310 {
1311 	struct eap_ttls_data *data = priv;
1312 
1313 	switch (data->state) {
1314 	case PHASE1:
1315 		if (eap_server_tls_phase1(sm, &data->ssl) < 0)
1316 			eap_ttls_state(data, FAILURE);
1317 		break;
1318 	case PHASE2_START:
1319 	case PHASE2_METHOD:
1320 	case PHASE_FINISHED:
1321 		eap_ttls_process_phase2(sm, data, data->ssl.in_buf);
1322 		eap_ttls_start_tnc(sm, data);
1323 		break;
1324 	case PHASE2_MSCHAPV2_RESP:
1325 		if (data->mschapv2_resp_ok && wpabuf_len(data->ssl.in_buf) ==
1326 		    0) {
1327 			wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAPV2: Peer "
1328 				   "acknowledged response");
1329 			eap_ttls_state(data, data->ttls_version > 0 ?
1330 				       PHASE_FINISHED : SUCCESS);
1331 		} else if (!data->mschapv2_resp_ok) {
1332 			wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAPV2: Peer "
1333 				   "acknowledged error");
1334 			eap_ttls_state(data, FAILURE);
1335 		} else {
1336 			wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAPV2: Unexpected "
1337 				   "frame from peer (payload len %lu, "
1338 				   "expected empty frame)",
1339 				   (unsigned long)
1340 				   wpabuf_len(data->ssl.in_buf));
1341 			eap_ttls_state(data, FAILURE);
1342 		}
1343 		eap_ttls_start_tnc(sm, data);
1344 		break;
1345 	default:
1346 		wpa_printf(MSG_DEBUG, "EAP-TTLS: Unexpected state %d in %s",
1347 			   data->state, __func__);
1348 		break;
1349 	}
1350 }
1351 
1352 
eap_ttls_process(struct eap_sm * sm,void * priv,struct wpabuf * respData)1353 static void eap_ttls_process(struct eap_sm *sm, void *priv,
1354 			     struct wpabuf *respData)
1355 {
1356 	struct eap_ttls_data *data = priv;
1357 	if (eap_server_tls_process(sm, &data->ssl, respData, data,
1358 				   EAP_TYPE_TTLS, eap_ttls_process_version,
1359 				   eap_ttls_process_msg) < 0)
1360 		eap_ttls_state(data, FAILURE);
1361 }
1362 
1363 
eap_ttls_isDone(struct eap_sm * sm,void * priv)1364 static Boolean eap_ttls_isDone(struct eap_sm *sm, void *priv)
1365 {
1366 	struct eap_ttls_data *data = priv;
1367 	return data->state == SUCCESS || data->state == FAILURE;
1368 }
1369 
1370 
eap_ttls_v1_derive_key(struct eap_sm * sm,struct eap_ttls_data * data)1371 static u8 * eap_ttls_v1_derive_key(struct eap_sm *sm,
1372 				   struct eap_ttls_data *data)
1373 {
1374 	struct tls_keys keys;
1375 	u8 *rnd, *key;
1376 
1377 	os_memset(&keys, 0, sizeof(keys));
1378 	if (tls_connection_get_keys(sm->ssl_ctx, data->ssl.conn, &keys) ||
1379 	    keys.client_random == NULL || keys.server_random == NULL ||
1380 	    keys.inner_secret == NULL) {
1381 		wpa_printf(MSG_INFO, "EAP-TTLS: Could not get inner secret, "
1382 			   "client random, or server random to derive keying "
1383 			   "material");
1384 		return NULL;
1385 	}
1386 
1387 	rnd = os_malloc(keys.client_random_len + keys.server_random_len);
1388 	key = os_malloc(EAP_TLS_KEY_LEN);
1389 	if (rnd == NULL || key == NULL) {
1390 		wpa_printf(MSG_INFO, "EAP-TTLS: No memory for key derivation");
1391 		os_free(rnd);
1392 		os_free(key);
1393 		return NULL;
1394 	}
1395 	os_memcpy(rnd, keys.client_random, keys.client_random_len);
1396 	os_memcpy(rnd + keys.client_random_len, keys.server_random,
1397 		  keys.server_random_len);
1398 
1399 	if (tls_prf(keys.inner_secret, keys.inner_secret_len,
1400 		    "ttls v1 keying material", rnd, keys.client_random_len +
1401 		    keys.server_random_len, key, EAP_TLS_KEY_LEN)) {
1402 		wpa_printf(MSG_DEBUG, "EAP-TTLS: Failed to derive key");
1403 		os_free(rnd);
1404 		os_free(key);
1405 		return NULL;
1406 	}
1407 
1408 	wpa_hexdump(MSG_DEBUG, "EAP-TTLS: client/server random",
1409 		    rnd, keys.client_random_len + keys.server_random_len);
1410 	wpa_hexdump_key(MSG_DEBUG, "EAP-TTLS: TLS/IA inner secret",
1411 			keys.inner_secret, keys.inner_secret_len);
1412 
1413 	os_free(rnd);
1414 
1415 	return key;
1416 }
1417 
1418 
eap_ttls_getKey(struct eap_sm * sm,void * priv,size_t * len)1419 static u8 * eap_ttls_getKey(struct eap_sm *sm, void *priv, size_t *len)
1420 {
1421 	struct eap_ttls_data *data = priv;
1422 	u8 *eapKeyData;
1423 
1424 	if (data->state != SUCCESS)
1425 		return NULL;
1426 
1427 	if (data->ttls_version == 0) {
1428 		eapKeyData = eap_server_tls_derive_key(sm, &data->ssl,
1429 						       "ttls keying material",
1430 						       EAP_TLS_KEY_LEN);
1431 	} else {
1432 		eapKeyData = eap_ttls_v1_derive_key(sm, data);
1433 	}
1434 
1435 	if (eapKeyData) {
1436 		*len = EAP_TLS_KEY_LEN;
1437 		wpa_hexdump_key(MSG_DEBUG, "EAP-TTLS: Derived key",
1438 				eapKeyData, EAP_TLS_KEY_LEN);
1439 	} else {
1440 		wpa_printf(MSG_DEBUG, "EAP-TTLS: Failed to derive key");
1441 	}
1442 
1443 	return eapKeyData;
1444 }
1445 
1446 
eap_ttls_isSuccess(struct eap_sm * sm,void * priv)1447 static Boolean eap_ttls_isSuccess(struct eap_sm *sm, void *priv)
1448 {
1449 	struct eap_ttls_data *data = priv;
1450 	return data->state == SUCCESS;
1451 }
1452 
1453 
eap_server_ttls_register(void)1454 int eap_server_ttls_register(void)
1455 {
1456 	struct eap_method *eap;
1457 	int ret;
1458 
1459 	eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
1460 				      EAP_VENDOR_IETF, EAP_TYPE_TTLS, "TTLS");
1461 	if (eap == NULL)
1462 		return -1;
1463 
1464 	eap->init = eap_ttls_init;
1465 	eap->reset = eap_ttls_reset;
1466 	eap->buildReq = eap_ttls_buildReq;
1467 	eap->check = eap_ttls_check;
1468 	eap->process = eap_ttls_process;
1469 	eap->isDone = eap_ttls_isDone;
1470 	eap->getKey = eap_ttls_getKey;
1471 	eap->isSuccess = eap_ttls_isSuccess;
1472 
1473 	ret = eap_server_method_register(eap);
1474 	if (ret)
1475 		eap_server_method_free(eap);
1476 	return ret;
1477 }
1478