xref: /freebsd/contrib/wpa/src/eap_peer/eap_tls.c (revision 7fdf597e96a02165cfe22ff357b857d5fa15ed8a)
1 /*
2  * EAP peer method: EAP-TLS (RFC 5216, RFC 9190)
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 	bool prot_success_received;
30 };
31 
32 
33 static void * eap_tls_init(struct eap_sm *sm)
34 {
35 	struct eap_tls_data *data;
36 	struct eap_peer_config *config = eap_get_config(sm);
37 	struct eap_peer_cert_config *cert;
38 
39 	if (!config)
40 		return NULL;
41 	if (!sm->init_phase2)
42 		cert = &config->cert;
43 	else if (sm->use_machine_cred)
44 		cert = &config->machine_cert;
45 	else
46 		cert = &config->phase2_cert;
47 	if (!cert->private_key && cert->engine == 0) {
48 		wpa_printf(MSG_INFO, "EAP-TLS: Private key not configured");
49 		return NULL;
50 	}
51 
52 	data = os_zalloc(sizeof(*data));
53 	if (data == NULL)
54 		return NULL;
55 
56 	data->ssl_ctx = sm->init_phase2 && sm->ssl_ctx2 ? sm->ssl_ctx2 :
57 		sm->ssl_ctx;
58 
59 	if (eap_peer_tls_ssl_init(sm, &data->ssl, config, EAP_TYPE_TLS)) {
60 		wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
61 		eap_tls_deinit(sm, data);
62 		if (cert->engine) {
63 			wpa_printf(MSG_DEBUG, "EAP-TLS: Requesting Smartcard "
64 				   "PIN");
65 			eap_sm_request_pin(sm);
66 			sm->ignore = true;
67 		} else if (cert->private_key && !cert->private_key_passwd) {
68 			wpa_printf(MSG_DEBUG, "EAP-TLS: Requesting private "
69 				   "key passphrase");
70 			eap_sm_request_passphrase(sm);
71 			sm->ignore = true;
72 		}
73 		return NULL;
74 	}
75 
76 	data->eap_type = EAP_TYPE_TLS;
77 
78 	return data;
79 }
80 
81 
82 #ifdef EAP_UNAUTH_TLS
83 static void * eap_unauth_tls_init(struct eap_sm *sm)
84 {
85 	struct eap_tls_data *data;
86 	struct eap_peer_config *config = eap_get_config(sm);
87 
88 	data = os_zalloc(sizeof(*data));
89 	if (data == NULL)
90 		return NULL;
91 
92 	data->ssl_ctx = sm->init_phase2 && sm->ssl_ctx2 ? sm->ssl_ctx2 :
93 		sm->ssl_ctx;
94 
95 	if (eap_peer_tls_ssl_init(sm, &data->ssl, config,
96 				  EAP_UNAUTH_TLS_TYPE)) {
97 		wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
98 		eap_tls_deinit(sm, data);
99 		return NULL;
100 	}
101 
102 	data->eap_type = EAP_UNAUTH_TLS_TYPE;
103 
104 	return data;
105 }
106 #endif /* EAP_UNAUTH_TLS */
107 
108 
109 #ifdef CONFIG_HS20
110 static void * eap_wfa_unauth_tls_init(struct eap_sm *sm)
111 {
112 	struct eap_tls_data *data;
113 	struct eap_peer_config *config = eap_get_config(sm);
114 
115 	data = os_zalloc(sizeof(*data));
116 	if (data == NULL)
117 		return NULL;
118 
119 	data->ssl_ctx = sm->init_phase2 && sm->ssl_ctx2 ? sm->ssl_ctx2 :
120 		sm->ssl_ctx;
121 
122 	if (eap_peer_tls_ssl_init(sm, &data->ssl, config,
123 				  EAP_WFA_UNAUTH_TLS_TYPE)) {
124 		wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
125 		eap_tls_deinit(sm, data);
126 		return NULL;
127 	}
128 
129 	data->eap_type = EAP_WFA_UNAUTH_TLS_TYPE;
130 
131 	return data;
132 }
133 #endif /* CONFIG_HS20 */
134 
135 
136 static void eap_tls_free_key(struct eap_tls_data *data)
137 {
138 	if (data->key_data) {
139 		bin_clear_free(data->key_data, EAP_TLS_KEY_LEN + EAP_EMSK_LEN);
140 		data->key_data = NULL;
141 	}
142 }
143 
144 
145 static void eap_tls_deinit(struct eap_sm *sm, void *priv)
146 {
147 	struct eap_tls_data *data = priv;
148 	if (data == NULL)
149 		return;
150 	eap_peer_tls_ssl_deinit(sm, &data->ssl);
151 	eap_tls_free_key(data);
152 	os_free(data->session_id);
153 	wpabuf_free(data->pending_resp);
154 	os_free(data);
155 }
156 
157 
158 static struct wpabuf * eap_tls_failure(struct eap_sm *sm,
159 				       struct eap_tls_data *data,
160 				       struct eap_method_ret *ret, int res,
161 				       struct wpabuf *resp, u8 id)
162 {
163 	wpa_printf(MSG_DEBUG, "EAP-TLS: TLS processing failed");
164 
165 	ret->methodState = METHOD_DONE;
166 	ret->decision = DECISION_FAIL;
167 
168 	if (resp) {
169 		/*
170 		 * This is likely an alert message, so send it instead of just
171 		 * ACKing the error.
172 		 */
173 		return resp;
174 	}
175 
176 	return eap_peer_tls_build_ack(id, data->eap_type, 0);
177 }
178 
179 
180 static void eap_tls_success(struct eap_sm *sm, struct eap_tls_data *data,
181 			    struct eap_method_ret *ret)
182 {
183 	const char *label;
184 	const u8 eap_tls13_context[] = { EAP_TYPE_TLS };
185 	const u8 *context = NULL;
186 	size_t context_len = 0;
187 
188 	wpa_printf(MSG_DEBUG, "EAP-TLS: Done");
189 
190 	if (data->ssl.tls_out) {
191 		wpa_printf(MSG_DEBUG, "EAP-TLS: Fragment(s) remaining");
192 		return;
193 	}
194 
195 	if (data->ssl.tls_v13) {
196 		label = "EXPORTER_EAP_TLS_Key_Material";
197 		context = eap_tls13_context;
198 		context_len = 1;
199 
200 		/* A possible NewSessionTicket may be received before
201 		 * EAP-Success, so need to allow it to be received. */
202 		ret->methodState = METHOD_MAY_CONT;
203 		ret->decision = DECISION_COND_SUCC;
204 	} else {
205 		label = "client EAP encryption";
206 
207 		ret->methodState = METHOD_DONE;
208 		ret->decision = DECISION_UNCOND_SUCC;
209 	}
210 
211 	eap_tls_free_key(data);
212 	data->key_data = eap_peer_tls_derive_key(sm, &data->ssl, label,
213 						 context, context_len,
214 						 EAP_TLS_KEY_LEN +
215 						 EAP_EMSK_LEN);
216 	if (data->key_data) {
217 		wpa_hexdump_key(MSG_DEBUG, "EAP-TLS: Derived key",
218 				data->key_data, EAP_TLS_KEY_LEN);
219 		wpa_hexdump_key(MSG_DEBUG, "EAP-TLS: Derived EMSK",
220 				data->key_data + EAP_TLS_KEY_LEN,
221 				EAP_EMSK_LEN);
222 	} else {
223 		wpa_printf(MSG_INFO, "EAP-TLS: Failed to derive key");
224 	}
225 
226 	os_free(data->session_id);
227 	data->session_id = eap_peer_tls_derive_session_id(sm, &data->ssl,
228 							  EAP_TYPE_TLS,
229 			                                  &data->id_len);
230 	if (data->session_id) {
231 		wpa_hexdump(MSG_DEBUG, "EAP-TLS: Derived Session-Id",
232 			    data->session_id, data->id_len);
233 	} else {
234 		wpa_printf(MSG_ERROR, "EAP-TLS: Failed to derive Session-Id");
235 	}
236 }
237 
238 
239 static struct wpabuf * eap_tls_process(struct eap_sm *sm, void *priv,
240 				       struct eap_method_ret *ret,
241 				       const struct wpabuf *reqData)
242 {
243 	size_t left;
244 	int res;
245 	struct wpabuf *resp;
246 	u8 flags, id;
247 	const u8 *pos;
248 	struct eap_tls_data *data = priv;
249 	struct wpabuf msg;
250 
251 	if (sm->waiting_ext_cert_check && data->pending_resp) {
252 		struct eap_peer_config *config = eap_get_config(sm);
253 
254 		if (config->pending_ext_cert_check == EXT_CERT_CHECK_GOOD) {
255 			wpa_printf(MSG_DEBUG,
256 				   "EAP-TLS: External certificate check succeeded - continue handshake");
257 			resp = data->pending_resp;
258 			data->pending_resp = NULL;
259 			sm->waiting_ext_cert_check = 0;
260 			return resp;
261 		}
262 
263 		if (config->pending_ext_cert_check == EXT_CERT_CHECK_BAD) {
264 			wpa_printf(MSG_DEBUG,
265 				   "EAP-TLS: External certificate check failed - force authentication failure");
266 			ret->methodState = METHOD_DONE;
267 			ret->decision = DECISION_FAIL;
268 			sm->waiting_ext_cert_check = 0;
269 			return NULL;
270 		}
271 
272 		wpa_printf(MSG_DEBUG,
273 			   "EAP-TLS: Continuing to wait external server certificate validation");
274 		return NULL;
275 	}
276 
277 	pos = eap_peer_tls_process_init(sm, &data->ssl, data->eap_type, ret,
278 					reqData, &left, &flags);
279 	if (pos == NULL)
280 		return NULL;
281 	id = eap_get_id(reqData);
282 
283 	if (flags & EAP_TLS_FLAGS_START) {
284 		wpa_printf(MSG_DEBUG, "EAP-TLS: Start");
285 		left = 0; /* make sure that this frame is empty, even though it
286 			   * should always be, anyway */
287 	}
288 
289 	resp = NULL;
290 	wpabuf_set(&msg, pos, left);
291 	res = eap_peer_tls_process_helper(sm, &data->ssl, data->eap_type, 0,
292 					  id, &msg, &resp);
293 
294 	if (res < 0) {
295 		return eap_tls_failure(sm, data, ret, res, resp, id);
296 	}
297 
298 	if (sm->waiting_ext_cert_check) {
299 		wpa_printf(MSG_DEBUG,
300 			   "EAP-TLS: Waiting external server certificate validation");
301 		wpabuf_free(data->pending_resp);
302 		data->pending_resp = resp;
303 		return NULL;
304 	}
305 
306 	/* RFC 9190 Section 2.5 */
307 	if (res == 2 && data->ssl.tls_v13 && wpabuf_len(resp) == 1 &&
308 	    *wpabuf_head_u8(resp) == 0) {
309 		wpa_printf(MSG_DEBUG,
310 			   "EAP-TLS: ACKing protected success indication (appl data 0x00)");
311 		eap_peer_tls_reset_output(&data->ssl);
312 		res = 1;
313 		ret->methodState = METHOD_DONE;
314 		ret->decision = DECISION_UNCOND_SUCC;
315 		data->prot_success_received = true;
316 	}
317 
318 	if (tls_connection_established(data->ssl_ctx, data->ssl.conn) &&
319 	    (!data->ssl.tls_v13 || data->prot_success_received))
320 		eap_tls_success(sm, data, ret);
321 
322 	if (res == 1) {
323 		wpabuf_free(resp);
324 		return eap_peer_tls_build_ack(id, data->eap_type, 0);
325 	}
326 
327 	return resp;
328 }
329 
330 
331 static bool eap_tls_has_reauth_data(struct eap_sm *sm, void *priv)
332 {
333 	struct eap_tls_data *data = priv;
334 	return tls_connection_established(data->ssl_ctx, data->ssl.conn);
335 }
336 
337 
338 static void eap_tls_deinit_for_reauth(struct eap_sm *sm, void *priv)
339 {
340 	struct eap_tls_data *data = priv;
341 
342 	wpabuf_free(data->pending_resp);
343 	data->pending_resp = NULL;
344 	data->prot_success_received = false;
345 }
346 
347 
348 static void * eap_tls_init_for_reauth(struct eap_sm *sm, void *priv)
349 {
350 	struct eap_tls_data *data = priv;
351 	eap_tls_free_key(data);
352 	os_free(data->session_id);
353 	data->session_id = NULL;
354 	if (eap_peer_tls_reauth_init(sm, &data->ssl)) {
355 		os_free(data);
356 		return NULL;
357 	}
358 	return priv;
359 }
360 
361 
362 static int eap_tls_get_status(struct eap_sm *sm, void *priv, char *buf,
363 			      size_t buflen, int verbose)
364 {
365 	struct eap_tls_data *data = priv;
366 	return eap_peer_tls_status(sm, &data->ssl, buf, buflen, verbose);
367 }
368 
369 
370 static bool eap_tls_isKeyAvailable(struct eap_sm *sm, void *priv)
371 {
372 	struct eap_tls_data *data = priv;
373 	return data->key_data != NULL;
374 }
375 
376 
377 static u8 * eap_tls_getKey(struct eap_sm *sm, void *priv, size_t *len)
378 {
379 	struct eap_tls_data *data = priv;
380 	u8 *key;
381 
382 	if (data->key_data == NULL)
383 		return NULL;
384 
385 	key = os_memdup(data->key_data, EAP_TLS_KEY_LEN);
386 	if (key == NULL)
387 		return NULL;
388 
389 	*len = EAP_TLS_KEY_LEN;
390 
391 	return key;
392 }
393 
394 
395 static u8 * eap_tls_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
396 {
397 	struct eap_tls_data *data = priv;
398 	u8 *key;
399 
400 	if (data->key_data == NULL)
401 		return NULL;
402 
403 	key = os_memdup(data->key_data + EAP_TLS_KEY_LEN, EAP_EMSK_LEN);
404 	if (key == NULL)
405 		return NULL;
406 
407 	*len = EAP_EMSK_LEN;
408 
409 	return key;
410 }
411 
412 
413 static u8 * eap_tls_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
414 {
415 	struct eap_tls_data *data = priv;
416 	u8 *id;
417 
418 	if (data->session_id == NULL)
419 		return NULL;
420 
421 	id = os_memdup(data->session_id, data->id_len);
422 	if (id == NULL)
423 		return NULL;
424 
425 	*len = data->id_len;
426 
427 	return id;
428 }
429 
430 
431 int eap_peer_tls_register(void)
432 {
433 	struct eap_method *eap;
434 
435 	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
436 				    EAP_VENDOR_IETF, EAP_TYPE_TLS, "TLS");
437 	if (eap == NULL)
438 		return -1;
439 
440 	eap->init = eap_tls_init;
441 	eap->deinit = eap_tls_deinit;
442 	eap->process = eap_tls_process;
443 	eap->isKeyAvailable = eap_tls_isKeyAvailable;
444 	eap->getKey = eap_tls_getKey;
445 	eap->getSessionId = eap_tls_get_session_id;
446 	eap->get_status = eap_tls_get_status;
447 	eap->has_reauth_data = eap_tls_has_reauth_data;
448 	eap->deinit_for_reauth = eap_tls_deinit_for_reauth;
449 	eap->init_for_reauth = eap_tls_init_for_reauth;
450 	eap->get_emsk = eap_tls_get_emsk;
451 
452 	return eap_peer_method_register(eap);
453 }
454 
455 
456 #ifdef EAP_UNAUTH_TLS
457 int eap_peer_unauth_tls_register(void)
458 {
459 	struct eap_method *eap;
460 
461 	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
462 				    EAP_VENDOR_UNAUTH_TLS,
463 				    EAP_VENDOR_TYPE_UNAUTH_TLS, "UNAUTH-TLS");
464 	if (eap == NULL)
465 		return -1;
466 
467 	eap->init = eap_unauth_tls_init;
468 	eap->deinit = eap_tls_deinit;
469 	eap->process = eap_tls_process;
470 	eap->isKeyAvailable = eap_tls_isKeyAvailable;
471 	eap->getKey = eap_tls_getKey;
472 	eap->get_status = eap_tls_get_status;
473 	eap->has_reauth_data = eap_tls_has_reauth_data;
474 	eap->deinit_for_reauth = eap_tls_deinit_for_reauth;
475 	eap->init_for_reauth = eap_tls_init_for_reauth;
476 	eap->get_emsk = eap_tls_get_emsk;
477 
478 	return eap_peer_method_register(eap);
479 }
480 #endif /* EAP_UNAUTH_TLS */
481 
482 
483 #ifdef CONFIG_HS20
484 int eap_peer_wfa_unauth_tls_register(void)
485 {
486 	struct eap_method *eap;
487 
488 	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
489 				    EAP_VENDOR_WFA_NEW,
490 				    EAP_VENDOR_WFA_UNAUTH_TLS,
491 				    "WFA-UNAUTH-TLS");
492 	if (eap == NULL)
493 		return -1;
494 
495 	eap->init = eap_wfa_unauth_tls_init;
496 	eap->deinit = eap_tls_deinit;
497 	eap->process = eap_tls_process;
498 	eap->isKeyAvailable = eap_tls_isKeyAvailable;
499 	eap->getKey = eap_tls_getKey;
500 	eap->get_status = eap_tls_get_status;
501 	eap->has_reauth_data = eap_tls_has_reauth_data;
502 	eap->deinit_for_reauth = eap_tls_deinit_for_reauth;
503 	eap->init_for_reauth = eap_tls_init_for_reauth;
504 	eap->get_emsk = eap_tls_get_emsk;
505 
506 	return eap_peer_method_register(eap);
507 }
508 #endif /* CONFIG_HS20 */
509