1 /*
2  * EAP peer method: EAP-TLS (RFC 2716)
3  * Copyright (c) 2004-2008, 2012-2019, 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 
9 #include "includes.h"
10 
11 #include "common.h"
12 #include "crypto/tls.h"
13 #include "eap_i.h"
14 #include "eap_tls_common.h"
15 #include "eap_config.h"
16 
17 
18 static void eap_tls_deinit(struct eap_sm *sm, void *priv);
19 
20 
21 struct eap_tls_data {
22 	struct eap_ssl_data ssl;
23 	u8 *key_data;
24 	u8 *session_id;
25 	size_t id_len;
26 	void *ssl_ctx;
27 	u8 eap_type;
28 	struct wpabuf *pending_resp;
29 };
30 
31 
eap_tls_init(struct eap_sm * sm)32 static void * eap_tls_init(struct eap_sm *sm)
33 {
34 	struct eap_tls_data *data;
35 	struct eap_peer_config *config = eap_get_config(sm);
36 	struct eap_peer_cert_config *cert;
37 
38 	if (!config)
39 		return NULL;
40 	if (!sm->init_phase2)
41 		cert = &config->cert;
42 	else if (sm->use_machine_cred)
43 		cert = &config->machine_cert;
44 	else
45 		cert = &config->phase2_cert;
46 	if (!cert->private_key && cert->engine == 0) {
47 		wpa_printf(MSG_INFO, "EAP-TLS: Private key not configured");
48 		return NULL;
49 	}
50 
51 	data = os_zalloc(sizeof(*data));
52 	if (data == NULL)
53 		return NULL;
54 
55 	data->ssl_ctx = sm->init_phase2 && sm->ssl_ctx2 ? sm->ssl_ctx2 :
56 		sm->ssl_ctx;
57 
58 	if (eap_peer_tls_ssl_init(sm, &data->ssl, config, EAP_TYPE_TLS)) {
59 		wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
60 		eap_tls_deinit(sm, data);
61 		if (cert->engine) {
62 			wpa_printf(MSG_DEBUG, "EAP-TLS: Requesting Smartcard "
63 				   "PIN");
64 			eap_sm_request_pin(sm);
65 			sm->ignore = true;
66 		} else if (cert->private_key && !cert->private_key_passwd) {
67 			wpa_printf(MSG_DEBUG, "EAP-TLS: Requesting private "
68 				   "key passphrase");
69 			eap_sm_request_passphrase(sm);
70 			sm->ignore = true;
71 		}
72 		return NULL;
73 	}
74 
75 	data->eap_type = EAP_TYPE_TLS;
76 
77 	return data;
78 }
79 
80 
81 #ifdef EAP_UNAUTH_TLS
eap_unauth_tls_init(struct eap_sm * sm)82 static void * eap_unauth_tls_init(struct eap_sm *sm)
83 {
84 	struct eap_tls_data *data;
85 	struct eap_peer_config *config = eap_get_config(sm);
86 
87 	data = os_zalloc(sizeof(*data));
88 	if (data == NULL)
89 		return NULL;
90 
91 	data->ssl_ctx = sm->init_phase2 && sm->ssl_ctx2 ? sm->ssl_ctx2 :
92 		sm->ssl_ctx;
93 
94 	if (eap_peer_tls_ssl_init(sm, &data->ssl, config,
95 				  EAP_UNAUTH_TLS_TYPE)) {
96 		wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
97 		eap_tls_deinit(sm, data);
98 		return NULL;
99 	}
100 
101 	data->eap_type = EAP_UNAUTH_TLS_TYPE;
102 
103 	return data;
104 }
105 #endif /* EAP_UNAUTH_TLS */
106 
107 
108 #ifdef CONFIG_HS20
eap_wfa_unauth_tls_init(struct eap_sm * sm)109 static void * eap_wfa_unauth_tls_init(struct eap_sm *sm)
110 {
111 	struct eap_tls_data *data;
112 	struct eap_peer_config *config = eap_get_config(sm);
113 
114 	data = os_zalloc(sizeof(*data));
115 	if (data == NULL)
116 		return NULL;
117 
118 	data->ssl_ctx = sm->init_phase2 && sm->ssl_ctx2 ? sm->ssl_ctx2 :
119 		sm->ssl_ctx;
120 
121 	if (eap_peer_tls_ssl_init(sm, &data->ssl, config,
122 				  EAP_WFA_UNAUTH_TLS_TYPE)) {
123 		wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
124 		eap_tls_deinit(sm, data);
125 		return NULL;
126 	}
127 
128 	data->eap_type = EAP_WFA_UNAUTH_TLS_TYPE;
129 
130 	return data;
131 }
132 #endif /* CONFIG_HS20 */
133 
134 
eap_tls_free_key(struct eap_tls_data * data)135 static void eap_tls_free_key(struct eap_tls_data *data)
136 {
137 	if (data->key_data) {
138 		bin_clear_free(data->key_data, EAP_TLS_KEY_LEN + EAP_EMSK_LEN);
139 		data->key_data = NULL;
140 	}
141 }
142 
143 
eap_tls_deinit(struct eap_sm * sm,void * priv)144 static void eap_tls_deinit(struct eap_sm *sm, void *priv)
145 {
146 	struct eap_tls_data *data = priv;
147 	if (data == NULL)
148 		return;
149 	eap_peer_tls_ssl_deinit(sm, &data->ssl);
150 	eap_tls_free_key(data);
151 	os_free(data->session_id);
152 	wpabuf_free(data->pending_resp);
153 	os_free(data);
154 }
155 
156 
eap_tls_failure(struct eap_sm * sm,struct eap_tls_data * data,struct eap_method_ret * ret,int res,struct wpabuf * resp,u8 id)157 static struct wpabuf * eap_tls_failure(struct eap_sm *sm,
158 				       struct eap_tls_data *data,
159 				       struct eap_method_ret *ret, int res,
160 				       struct wpabuf *resp, u8 id)
161 {
162 	wpa_printf(MSG_DEBUG, "EAP-TLS: TLS processing failed");
163 
164 	ret->methodState = METHOD_DONE;
165 	ret->decision = DECISION_FAIL;
166 
167 	if (resp) {
168 		/*
169 		 * This is likely an alert message, so send it instead of just
170 		 * ACKing the error.
171 		 */
172 		return resp;
173 	}
174 
175 	return eap_peer_tls_build_ack(id, data->eap_type, 0);
176 }
177 
178 
eap_tls_success(struct eap_sm * sm,struct eap_tls_data * data,struct eap_method_ret * ret)179 static void eap_tls_success(struct eap_sm *sm, struct eap_tls_data *data,
180 			    struct eap_method_ret *ret)
181 {
182 	const char *label;
183 	const u8 eap_tls13_context[] = { EAP_TYPE_TLS };
184 	const u8 *context = NULL;
185 	size_t context_len = 0;
186 
187 	wpa_printf(MSG_DEBUG, "EAP-TLS: Done");
188 
189 	if (data->ssl.tls_out) {
190 		wpa_printf(MSG_DEBUG, "EAP-TLS: Fragment(s) remaining");
191 		return;
192 	}
193 
194 	if (data->ssl.tls_v13) {
195 		label = "EXPORTER_EAP_TLS_Key_Material";
196 		context = eap_tls13_context;
197 		context_len = 1;
198 
199 		/* A possible NewSessionTicket may be received before
200 		 * EAP-Success, so need to allow it to be received. */
201 		ret->methodState = METHOD_MAY_CONT;
202 		ret->decision = DECISION_COND_SUCC;
203 	} else {
204 		label = "client EAP encryption";
205 
206 		ret->methodState = METHOD_DONE;
207 		ret->decision = DECISION_UNCOND_SUCC;
208 	}
209 
210 	eap_tls_free_key(data);
211 	data->key_data = eap_peer_tls_derive_key(sm, &data->ssl, label,
212 						 context, context_len,
213 						 EAP_TLS_KEY_LEN +
214 						 EAP_EMSK_LEN);
215 	if (data->key_data) {
216 		wpa_hexdump_key(MSG_DEBUG, "EAP-TLS: Derived key",
217 				data->key_data, EAP_TLS_KEY_LEN);
218 		wpa_hexdump_key(MSG_DEBUG, "EAP-TLS: Derived EMSK",
219 				data->key_data + EAP_TLS_KEY_LEN,
220 				EAP_EMSK_LEN);
221 	} else {
222 		wpa_printf(MSG_INFO, "EAP-TLS: Failed to derive key");
223 	}
224 
225 	os_free(data->session_id);
226 	data->session_id = eap_peer_tls_derive_session_id(sm, &data->ssl,
227 							  EAP_TYPE_TLS,
228 			                                  &data->id_len);
229 	if (data->session_id) {
230 		wpa_hexdump(MSG_DEBUG, "EAP-TLS: Derived Session-Id",
231 			    data->session_id, data->id_len);
232 	} else {
233 		wpa_printf(MSG_ERROR, "EAP-TLS: Failed to derive Session-Id");
234 	}
235 }
236 
237 
eap_tls_process(struct eap_sm * sm,void * priv,struct eap_method_ret * ret,const struct wpabuf * reqData)238 static struct wpabuf * eap_tls_process(struct eap_sm *sm, void *priv,
239 				       struct eap_method_ret *ret,
240 				       const struct wpabuf *reqData)
241 {
242 	size_t left;
243 	int res;
244 	struct wpabuf *resp;
245 	u8 flags, id;
246 	const u8 *pos;
247 	struct eap_tls_data *data = priv;
248 	struct wpabuf msg;
249 
250 	if (sm->waiting_ext_cert_check && data->pending_resp) {
251 		struct eap_peer_config *config = eap_get_config(sm);
252 
253 		if (config->pending_ext_cert_check == EXT_CERT_CHECK_GOOD) {
254 			wpa_printf(MSG_DEBUG,
255 				   "EAP-TLS: External certificate check succeeded - continue handshake");
256 			resp = data->pending_resp;
257 			data->pending_resp = NULL;
258 			sm->waiting_ext_cert_check = 0;
259 			return resp;
260 		}
261 
262 		if (config->pending_ext_cert_check == EXT_CERT_CHECK_BAD) {
263 			wpa_printf(MSG_DEBUG,
264 				   "EAP-TLS: External certificate check failed - force authentication failure");
265 			ret->methodState = METHOD_DONE;
266 			ret->decision = DECISION_FAIL;
267 			sm->waiting_ext_cert_check = 0;
268 			return NULL;
269 		}
270 
271 		wpa_printf(MSG_DEBUG,
272 			   "EAP-TLS: Continuing to wait external server certificate validation");
273 		return NULL;
274 	}
275 
276 	pos = eap_peer_tls_process_init(sm, &data->ssl, data->eap_type, ret,
277 					reqData, &left, &flags);
278 	if (pos == NULL)
279 		return NULL;
280 	id = eap_get_id(reqData);
281 
282 	if (flags & EAP_TLS_FLAGS_START) {
283 		wpa_printf(MSG_DEBUG, "EAP-TLS: Start");
284 		left = 0; /* make sure that this frame is empty, even though it
285 			   * should always be, anyway */
286 	}
287 
288 	resp = NULL;
289 	wpabuf_set(&msg, pos, left);
290 	res = eap_peer_tls_process_helper(sm, &data->ssl, data->eap_type, 0,
291 					  id, &msg, &resp);
292 
293 	if (res < 0) {
294 		return eap_tls_failure(sm, data, ret, res, resp, id);
295 	}
296 
297 	if (sm->waiting_ext_cert_check) {
298 		wpa_printf(MSG_DEBUG,
299 			   "EAP-TLS: Waiting external server certificate validation");
300 		wpabuf_free(data->pending_resp);
301 		data->pending_resp = resp;
302 		return NULL;
303 	}
304 
305 	/* draft-ietf-emu-eap-tls13-13 Section 2.5 */
306 	if (res == 2 && data->ssl.tls_v13 && wpabuf_len(resp) == 1 &&
307 	    *wpabuf_head_u8(resp) == 0) {
308 		wpa_printf(MSG_DEBUG, "EAP-TLS: ACKing Commitment Message");
309 		eap_peer_tls_reset_output(&data->ssl);
310 		res = 1;
311 	}
312 
313 	if (tls_connection_established(data->ssl_ctx, data->ssl.conn))
314 		eap_tls_success(sm, data, ret);
315 
316 	if (res == 1) {
317 		wpabuf_free(resp);
318 		return eap_peer_tls_build_ack(id, data->eap_type, 0);
319 	}
320 
321 	return resp;
322 }
323 
324 
eap_tls_has_reauth_data(struct eap_sm * sm,void * priv)325 static bool eap_tls_has_reauth_data(struct eap_sm *sm, void *priv)
326 {
327 	struct eap_tls_data *data = priv;
328 	return tls_connection_established(data->ssl_ctx, data->ssl.conn);
329 }
330 
331 
eap_tls_deinit_for_reauth(struct eap_sm * sm,void * priv)332 static void eap_tls_deinit_for_reauth(struct eap_sm *sm, void *priv)
333 {
334 	struct eap_tls_data *data = priv;
335 
336 	wpabuf_free(data->pending_resp);
337 	data->pending_resp = NULL;
338 }
339 
340 
eap_tls_init_for_reauth(struct eap_sm * sm,void * priv)341 static void * eap_tls_init_for_reauth(struct eap_sm *sm, void *priv)
342 {
343 	struct eap_tls_data *data = priv;
344 	eap_tls_free_key(data);
345 	os_free(data->session_id);
346 	data->session_id = NULL;
347 	if (eap_peer_tls_reauth_init(sm, &data->ssl)) {
348 		os_free(data);
349 		return NULL;
350 	}
351 	return priv;
352 }
353 
354 
eap_tls_get_status(struct eap_sm * sm,void * priv,char * buf,size_t buflen,int verbose)355 static int eap_tls_get_status(struct eap_sm *sm, void *priv, char *buf,
356 			      size_t buflen, int verbose)
357 {
358 	struct eap_tls_data *data = priv;
359 	return eap_peer_tls_status(sm, &data->ssl, buf, buflen, verbose);
360 }
361 
362 
eap_tls_isKeyAvailable(struct eap_sm * sm,void * priv)363 static bool eap_tls_isKeyAvailable(struct eap_sm *sm, void *priv)
364 {
365 	struct eap_tls_data *data = priv;
366 	return data->key_data != NULL;
367 }
368 
369 
eap_tls_getKey(struct eap_sm * sm,void * priv,size_t * len)370 static u8 * eap_tls_getKey(struct eap_sm *sm, void *priv, size_t *len)
371 {
372 	struct eap_tls_data *data = priv;
373 	u8 *key;
374 
375 	if (data->key_data == NULL)
376 		return NULL;
377 
378 	key = os_memdup(data->key_data, EAP_TLS_KEY_LEN);
379 	if (key == NULL)
380 		return NULL;
381 
382 	*len = EAP_TLS_KEY_LEN;
383 
384 	return key;
385 }
386 
387 
eap_tls_get_emsk(struct eap_sm * sm,void * priv,size_t * len)388 static u8 * eap_tls_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
389 {
390 	struct eap_tls_data *data = priv;
391 	u8 *key;
392 
393 	if (data->key_data == NULL)
394 		return NULL;
395 
396 	key = os_memdup(data->key_data + EAP_TLS_KEY_LEN, EAP_EMSK_LEN);
397 	if (key == NULL)
398 		return NULL;
399 
400 	*len = EAP_EMSK_LEN;
401 
402 	return key;
403 }
404 
405 
eap_tls_get_session_id(struct eap_sm * sm,void * priv,size_t * len)406 static u8 * eap_tls_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
407 {
408 	struct eap_tls_data *data = priv;
409 	u8 *id;
410 
411 	if (data->session_id == NULL)
412 		return NULL;
413 
414 	id = os_memdup(data->session_id, data->id_len);
415 	if (id == NULL)
416 		return NULL;
417 
418 	*len = data->id_len;
419 
420 	return id;
421 }
422 
423 
eap_peer_tls_register(void)424 int eap_peer_tls_register(void)
425 {
426 	struct eap_method *eap;
427 
428 	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
429 				    EAP_VENDOR_IETF, EAP_TYPE_TLS, "TLS");
430 	if (eap == NULL)
431 		return -1;
432 
433 	eap->init = eap_tls_init;
434 	eap->deinit = eap_tls_deinit;
435 	eap->process = eap_tls_process;
436 	eap->isKeyAvailable = eap_tls_isKeyAvailable;
437 	eap->getKey = eap_tls_getKey;
438 	eap->getSessionId = eap_tls_get_session_id;
439 	eap->get_status = eap_tls_get_status;
440 	eap->has_reauth_data = eap_tls_has_reauth_data;
441 	eap->deinit_for_reauth = eap_tls_deinit_for_reauth;
442 	eap->init_for_reauth = eap_tls_init_for_reauth;
443 	eap->get_emsk = eap_tls_get_emsk;
444 
445 	return eap_peer_method_register(eap);
446 }
447 
448 
449 #ifdef EAP_UNAUTH_TLS
eap_peer_unauth_tls_register(void)450 int eap_peer_unauth_tls_register(void)
451 {
452 	struct eap_method *eap;
453 
454 	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
455 				    EAP_VENDOR_UNAUTH_TLS,
456 				    EAP_VENDOR_TYPE_UNAUTH_TLS, "UNAUTH-TLS");
457 	if (eap == NULL)
458 		return -1;
459 
460 	eap->init = eap_unauth_tls_init;
461 	eap->deinit = eap_tls_deinit;
462 	eap->process = eap_tls_process;
463 	eap->isKeyAvailable = eap_tls_isKeyAvailable;
464 	eap->getKey = eap_tls_getKey;
465 	eap->get_status = eap_tls_get_status;
466 	eap->has_reauth_data = eap_tls_has_reauth_data;
467 	eap->deinit_for_reauth = eap_tls_deinit_for_reauth;
468 	eap->init_for_reauth = eap_tls_init_for_reauth;
469 	eap->get_emsk = eap_tls_get_emsk;
470 
471 	return eap_peer_method_register(eap);
472 }
473 #endif /* EAP_UNAUTH_TLS */
474 
475 
476 #ifdef CONFIG_HS20
eap_peer_wfa_unauth_tls_register(void)477 int eap_peer_wfa_unauth_tls_register(void)
478 {
479 	struct eap_method *eap;
480 
481 	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
482 				    EAP_VENDOR_WFA_NEW,
483 				    EAP_VENDOR_WFA_UNAUTH_TLS,
484 				    "WFA-UNAUTH-TLS");
485 	if (eap == NULL)
486 		return -1;
487 
488 	eap->init = eap_wfa_unauth_tls_init;
489 	eap->deinit = eap_tls_deinit;
490 	eap->process = eap_tls_process;
491 	eap->isKeyAvailable = eap_tls_isKeyAvailable;
492 	eap->getKey = eap_tls_getKey;
493 	eap->get_status = eap_tls_get_status;
494 	eap->has_reauth_data = eap_tls_has_reauth_data;
495 	eap->deinit_for_reauth = eap_tls_deinit_for_reauth;
496 	eap->init_for_reauth = eap_tls_init_for_reauth;
497 	eap->get_emsk = eap_tls_get_emsk;
498 
499 	return eap_peer_method_register(eap);
500 }
501 #endif /* CONFIG_HS20 */
502