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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 	if (res == 2) {
306 		/* Application data included in the handshake message (used by
307 		 * EAP-TLS 1.3 to indicate conclusion of the exchange). */
308 		wpa_hexdump_buf(MSG_DEBUG, "EAP-TLS: Received Application Data",
309 				resp);
310 		wpa_hexdump_buf(MSG_DEBUG, "EAP-TLS: Remaining tls_out data",
311 				data->ssl.tls_out);
312 		eap_peer_tls_reset_output(&data->ssl);
313 		/* Send an ACK to allow the server to complete exchange */
314 		res = 1;
315 	}
316 
317 	if (tls_connection_established(data->ssl_ctx, data->ssl.conn))
318 		eap_tls_success(sm, data, ret);
319 
320 	if (res == 1) {
321 		wpabuf_free(resp);
322 		return eap_peer_tls_build_ack(id, data->eap_type, 0);
323 	}
324 
325 	return resp;
326 }
327 
328 
eap_tls_has_reauth_data(struct eap_sm * sm,void * priv)329 static bool eap_tls_has_reauth_data(struct eap_sm *sm, void *priv)
330 {
331 	struct eap_tls_data *data = priv;
332 	return tls_connection_established(data->ssl_ctx, data->ssl.conn);
333 }
334 
335 
eap_tls_deinit_for_reauth(struct eap_sm * sm,void * priv)336 static void eap_tls_deinit_for_reauth(struct eap_sm *sm, void *priv)
337 {
338 	struct eap_tls_data *data = priv;
339 
340 	wpabuf_free(data->pending_resp);
341 	data->pending_resp = NULL;
342 }
343 
344 
eap_tls_init_for_reauth(struct eap_sm * sm,void * priv)345 static void * eap_tls_init_for_reauth(struct eap_sm *sm, void *priv)
346 {
347 	struct eap_tls_data *data = priv;
348 	eap_tls_free_key(data);
349 	os_free(data->session_id);
350 	data->session_id = NULL;
351 	if (eap_peer_tls_reauth_init(sm, &data->ssl)) {
352 		os_free(data);
353 		return NULL;
354 	}
355 	return priv;
356 }
357 
358 
eap_tls_get_status(struct eap_sm * sm,void * priv,char * buf,size_t buflen,int verbose)359 static int eap_tls_get_status(struct eap_sm *sm, void *priv, char *buf,
360 			      size_t buflen, int verbose)
361 {
362 	struct eap_tls_data *data = priv;
363 	return eap_peer_tls_status(sm, &data->ssl, buf, buflen, verbose);
364 }
365 
366 
eap_tls_isKeyAvailable(struct eap_sm * sm,void * priv)367 static bool eap_tls_isKeyAvailable(struct eap_sm *sm, void *priv)
368 {
369 	struct eap_tls_data *data = priv;
370 	return data->key_data != NULL;
371 }
372 
373 
eap_tls_getKey(struct eap_sm * sm,void * priv,size_t * len)374 static u8 * eap_tls_getKey(struct eap_sm *sm, void *priv, size_t *len)
375 {
376 	struct eap_tls_data *data = priv;
377 	u8 *key;
378 
379 	if (data->key_data == NULL)
380 		return NULL;
381 
382 	key = os_memdup(data->key_data, EAP_TLS_KEY_LEN);
383 	if (key == NULL)
384 		return NULL;
385 
386 	*len = EAP_TLS_KEY_LEN;
387 
388 	return key;
389 }
390 
391 
eap_tls_get_emsk(struct eap_sm * sm,void * priv,size_t * len)392 static u8 * eap_tls_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
393 {
394 	struct eap_tls_data *data = priv;
395 	u8 *key;
396 
397 	if (data->key_data == NULL)
398 		return NULL;
399 
400 	key = os_memdup(data->key_data + EAP_TLS_KEY_LEN, EAP_EMSK_LEN);
401 	if (key == NULL)
402 		return NULL;
403 
404 	*len = EAP_EMSK_LEN;
405 
406 	return key;
407 }
408 
409 
eap_tls_get_session_id(struct eap_sm * sm,void * priv,size_t * len)410 static u8 * eap_tls_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
411 {
412 	struct eap_tls_data *data = priv;
413 	u8 *id;
414 
415 	if (data->session_id == NULL)
416 		return NULL;
417 
418 	id = os_memdup(data->session_id, data->id_len);
419 	if (id == NULL)
420 		return NULL;
421 
422 	*len = data->id_len;
423 
424 	return id;
425 }
426 
427 
eap_peer_tls_register(void)428 int eap_peer_tls_register(void)
429 {
430 	struct eap_method *eap;
431 
432 	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
433 				    EAP_VENDOR_IETF, EAP_TYPE_TLS, "TLS");
434 	if (eap == NULL)
435 		return -1;
436 
437 	eap->init = eap_tls_init;
438 	eap->deinit = eap_tls_deinit;
439 	eap->process = eap_tls_process;
440 	eap->isKeyAvailable = eap_tls_isKeyAvailable;
441 	eap->getKey = eap_tls_getKey;
442 	eap->getSessionId = eap_tls_get_session_id;
443 	eap->get_status = eap_tls_get_status;
444 	eap->has_reauth_data = eap_tls_has_reauth_data;
445 	eap->deinit_for_reauth = eap_tls_deinit_for_reauth;
446 	eap->init_for_reauth = eap_tls_init_for_reauth;
447 	eap->get_emsk = eap_tls_get_emsk;
448 
449 	return eap_peer_method_register(eap);
450 }
451 
452 
453 #ifdef EAP_UNAUTH_TLS
eap_peer_unauth_tls_register(void)454 int eap_peer_unauth_tls_register(void)
455 {
456 	struct eap_method *eap;
457 
458 	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
459 				    EAP_VENDOR_UNAUTH_TLS,
460 				    EAP_VENDOR_TYPE_UNAUTH_TLS, "UNAUTH-TLS");
461 	if (eap == NULL)
462 		return -1;
463 
464 	eap->init = eap_unauth_tls_init;
465 	eap->deinit = eap_tls_deinit;
466 	eap->process = eap_tls_process;
467 	eap->isKeyAvailable = eap_tls_isKeyAvailable;
468 	eap->getKey = eap_tls_getKey;
469 	eap->get_status = eap_tls_get_status;
470 	eap->has_reauth_data = eap_tls_has_reauth_data;
471 	eap->deinit_for_reauth = eap_tls_deinit_for_reauth;
472 	eap->init_for_reauth = eap_tls_init_for_reauth;
473 	eap->get_emsk = eap_tls_get_emsk;
474 
475 	return eap_peer_method_register(eap);
476 }
477 #endif /* EAP_UNAUTH_TLS */
478 
479 
480 #ifdef CONFIG_HS20
eap_peer_wfa_unauth_tls_register(void)481 int eap_peer_wfa_unauth_tls_register(void)
482 {
483 	struct eap_method *eap;
484 
485 	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
486 				    EAP_VENDOR_WFA_NEW,
487 				    EAP_VENDOR_WFA_UNAUTH_TLS,
488 				    "WFA-UNAUTH-TLS");
489 	if (eap == NULL)
490 		return -1;
491 
492 	eap->init = eap_wfa_unauth_tls_init;
493 	eap->deinit = eap_tls_deinit;
494 	eap->process = eap_tls_process;
495 	eap->isKeyAvailable = eap_tls_isKeyAvailable;
496 	eap->getKey = eap_tls_getKey;
497 	eap->get_status = eap_tls_get_status;
498 	eap->has_reauth_data = eap_tls_has_reauth_data;
499 	eap->deinit_for_reauth = eap_tls_deinit_for_reauth;
500 	eap->init_for_reauth = eap_tls_init_for_reauth;
501 	eap->get_emsk = eap_tls_get_emsk;
502 
503 	return eap_peer_method_register(eap);
504 }
505 #endif /* CONFIG_HS20 */
506