eap_tls.c revision f86232838cf712377867cb42417c1613ab5dc425 
1/*
2 * EAP peer method: EAP-TLS (RFC 2716)
3 * Copyright (c) 2004-2008, 2012, 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
18static void eap_tls_deinit(struct eap_sm *sm, void *priv);
19
20
21struct 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};
29
30
31static void * eap_tls_init(struct eap_sm *sm)
32{
33	struct eap_tls_data *data;
34	struct eap_peer_config *config = eap_get_config(sm);
35	if (config == NULL ||
36	    ((sm->init_phase2 ? config->private_key2 : config->private_key)
37	     == NULL &&
38	     (sm->init_phase2 ? config->engine2 : config->engine) == 0)) {
39		wpa_printf(MSG_INFO, "EAP-TLS: Private key not configured");
40		return NULL;
41	}
42
43	data = os_zalloc(sizeof(*data));
44	if (data == NULL)
45		return NULL;
46
47	data->ssl_ctx = sm->init_phase2 && sm->ssl_ctx2 ? sm->ssl_ctx2 :
48		sm->ssl_ctx;
49
50	if (eap_peer_tls_ssl_init(sm, &data->ssl, config, EAP_TYPE_TLS)) {
51		wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
52		eap_tls_deinit(sm, data);
53		if (config->engine) {
54			wpa_printf(MSG_DEBUG, "EAP-TLS: Requesting Smartcard "
55				   "PIN");
56			eap_sm_request_pin(sm);
57			sm->ignore = TRUE;
58		} else if (config->private_key && !config->private_key_passwd)
59		{
60			wpa_printf(MSG_DEBUG, "EAP-TLS: Requesting private "
61				   "key passphrase");
62			eap_sm_request_passphrase(sm);
63			sm->ignore = TRUE;
64		}
65		return NULL;
66	}
67
68	data->eap_type = EAP_TYPE_TLS;
69
70	return data;
71}
72
73
74#ifdef EAP_UNAUTH_TLS
75static void * eap_unauth_tls_init(struct eap_sm *sm)
76{
77	struct eap_tls_data *data;
78	struct eap_peer_config *config = eap_get_config(sm);
79
80	data = os_zalloc(sizeof(*data));
81	if (data == NULL)
82		return NULL;
83
84	data->ssl_ctx = sm->init_phase2 && sm->ssl_ctx2 ? sm->ssl_ctx2 :
85		sm->ssl_ctx;
86
87	if (eap_peer_tls_ssl_init(sm, &data->ssl, config,
88				  EAP_UNAUTH_TLS_TYPE)) {
89		wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
90		eap_tls_deinit(sm, data);
91		return NULL;
92	}
93
94	data->eap_type = EAP_UNAUTH_TLS_TYPE;
95
96	return data;
97}
98#endif /* EAP_UNAUTH_TLS */
99
100
101static void eap_tls_deinit(struct eap_sm *sm, void *priv)
102{
103	struct eap_tls_data *data = priv;
104	if (data == NULL)
105		return;
106	eap_peer_tls_ssl_deinit(sm, &data->ssl);
107	os_free(data->key_data);
108	os_free(data->session_id);
109	os_free(data);
110}
111
112
113static struct wpabuf * eap_tls_failure(struct eap_sm *sm,
114				       struct eap_tls_data *data,
115				       struct eap_method_ret *ret, int res,
116				       struct wpabuf *resp, u8 id)
117{
118	wpa_printf(MSG_DEBUG, "EAP-TLS: TLS processing failed");
119
120	ret->methodState = METHOD_DONE;
121	ret->decision = DECISION_FAIL;
122
123	if (res == -1) {
124		struct eap_peer_config *config = eap_get_config(sm);
125		if (config) {
126			/*
127			 * The TLS handshake failed. So better forget the old
128			 * PIN. It may be wrong, we cannot be sure but trying
129			 * the wrong one again might block it on the card--so
130			 * better ask the user again.
131			 */
132			os_free(config->pin);
133			config->pin = NULL;
134		}
135	}
136
137	if (resp) {
138		/*
139		 * This is likely an alert message, so send it instead of just
140		 * ACKing the error.
141		 */
142		return resp;
143	}
144
145	return eap_peer_tls_build_ack(id, data->eap_type, 0);
146}
147
148
149static void eap_tls_success(struct eap_sm *sm, struct eap_tls_data *data,
150			    struct eap_method_ret *ret)
151{
152	wpa_printf(MSG_DEBUG, "EAP-TLS: Done");
153
154	ret->methodState = METHOD_DONE;
155	ret->decision = DECISION_UNCOND_SUCC;
156
157	os_free(data->key_data);
158	data->key_data = eap_peer_tls_derive_key(sm, &data->ssl,
159						 "client EAP encryption",
160						 EAP_TLS_KEY_LEN +
161						 EAP_EMSK_LEN);
162	if (data->key_data) {
163		wpa_hexdump_key(MSG_DEBUG, "EAP-TLS: Derived key",
164				data->key_data, EAP_TLS_KEY_LEN);
165		wpa_hexdump_key(MSG_DEBUG, "EAP-TLS: Derived EMSK",
166				data->key_data + EAP_TLS_KEY_LEN,
167				EAP_EMSK_LEN);
168	} else {
169		wpa_printf(MSG_INFO, "EAP-TLS: Failed to derive key");
170	}
171
172	os_free(data->session_id);
173	data->session_id = eap_peer_tls_derive_session_id(sm, &data->ssl,
174							  EAP_TYPE_TLS,
175			                                  &data->id_len);
176	if (data->session_id) {
177		wpa_hexdump(MSG_DEBUG, "EAP-TLS: Derived Session-Id",
178			    data->session_id, data->id_len);
179	} else {
180		wpa_printf(MSG_ERROR, "EAP-TLS: Failed to derive Session-Id");
181	}
182}
183
184
185static struct wpabuf * eap_tls_process(struct eap_sm *sm, void *priv,
186				       struct eap_method_ret *ret,
187				       const struct wpabuf *reqData)
188{
189	size_t left;
190	int res;
191	struct wpabuf *resp;
192	u8 flags, id;
193	const u8 *pos;
194	struct eap_tls_data *data = priv;
195
196	pos = eap_peer_tls_process_init(sm, &data->ssl, data->eap_type, ret,
197					reqData, &left, &flags);
198	if (pos == NULL)
199		return NULL;
200	id = eap_get_id(reqData);
201
202	if (flags & EAP_TLS_FLAGS_START) {
203		wpa_printf(MSG_DEBUG, "EAP-TLS: Start");
204		left = 0; /* make sure that this frame is empty, even though it
205			   * should always be, anyway */
206	}
207
208	resp = NULL;
209	res = eap_peer_tls_process_helper(sm, &data->ssl, data->eap_type, 0,
210					  id, pos, left, &resp);
211
212	if (res < 0) {
213		return eap_tls_failure(sm, data, ret, res, resp, id);
214	}
215
216	if (tls_connection_established(data->ssl_ctx, data->ssl.conn))
217		eap_tls_success(sm, data, ret);
218
219	if (res == 1) {
220		wpabuf_free(resp);
221		return eap_peer_tls_build_ack(id, data->eap_type, 0);
222	}
223
224	return resp;
225}
226
227
228static Boolean eap_tls_has_reauth_data(struct eap_sm *sm, void *priv)
229{
230	struct eap_tls_data *data = priv;
231	return tls_connection_established(data->ssl_ctx, data->ssl.conn);
232}
233
234
235static void eap_tls_deinit_for_reauth(struct eap_sm *sm, void *priv)
236{
237}
238
239
240static void * eap_tls_init_for_reauth(struct eap_sm *sm, void *priv)
241{
242	struct eap_tls_data *data = priv;
243	os_free(data->key_data);
244	data->key_data = NULL;
245	os_free(data->session_id);
246	data->session_id = NULL;
247	if (eap_peer_tls_reauth_init(sm, &data->ssl)) {
248		os_free(data);
249		return NULL;
250	}
251	return priv;
252}
253
254
255static int eap_tls_get_status(struct eap_sm *sm, void *priv, char *buf,
256			      size_t buflen, int verbose)
257{
258	struct eap_tls_data *data = priv;
259	return eap_peer_tls_status(sm, &data->ssl, buf, buflen, verbose);
260}
261
262
263static Boolean eap_tls_isKeyAvailable(struct eap_sm *sm, void *priv)
264{
265	struct eap_tls_data *data = priv;
266	return data->key_data != NULL;
267}
268
269
270static u8 * eap_tls_getKey(struct eap_sm *sm, void *priv, size_t *len)
271{
272	struct eap_tls_data *data = priv;
273	u8 *key;
274
275	if (data->key_data == NULL)
276		return NULL;
277
278	key = os_malloc(EAP_TLS_KEY_LEN);
279	if (key == NULL)
280		return NULL;
281
282	*len = EAP_TLS_KEY_LEN;
283	os_memcpy(key, data->key_data, EAP_TLS_KEY_LEN);
284
285	return key;
286}
287
288
289static u8 * eap_tls_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
290{
291	struct eap_tls_data *data = priv;
292	u8 *key;
293
294	if (data->key_data == NULL)
295		return NULL;
296
297	key = os_malloc(EAP_EMSK_LEN);
298	if (key == NULL)
299		return NULL;
300
301	*len = EAP_EMSK_LEN;
302	os_memcpy(key, data->key_data + EAP_TLS_KEY_LEN, EAP_EMSK_LEN);
303
304	return key;
305}
306
307
308static u8 * eap_tls_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
309{
310	struct eap_tls_data *data = priv;
311	u8 *id;
312
313	if (data->session_id == NULL)
314		return NULL;
315
316	id = os_malloc(data->id_len);
317	if (id == NULL)
318		return NULL;
319
320	*len = data->id_len;
321	os_memcpy(id, data->session_id, data->id_len);
322
323	return id;
324}
325
326
327int eap_peer_tls_register(void)
328{
329	struct eap_method *eap;
330	int ret;
331
332	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
333				    EAP_VENDOR_IETF, EAP_TYPE_TLS, "TLS");
334	if (eap == NULL)
335		return -1;
336
337	eap->init = eap_tls_init;
338	eap->deinit = eap_tls_deinit;
339	eap->process = eap_tls_process;
340	eap->isKeyAvailable = eap_tls_isKeyAvailable;
341	eap->getKey = eap_tls_getKey;
342	eap->getSessionId = eap_tls_get_session_id;
343	eap->get_status = eap_tls_get_status;
344	eap->has_reauth_data = eap_tls_has_reauth_data;
345	eap->deinit_for_reauth = eap_tls_deinit_for_reauth;
346	eap->init_for_reauth = eap_tls_init_for_reauth;
347	eap->get_emsk = eap_tls_get_emsk;
348
349	ret = eap_peer_method_register(eap);
350	if (ret)
351		eap_peer_method_free(eap);
352	return ret;
353}
354
355
356#ifdef EAP_UNAUTH_TLS
357int eap_peer_unauth_tls_register(void)
358{
359	struct eap_method *eap;
360	int ret;
361
362	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
363				    EAP_VENDOR_UNAUTH_TLS,
364				    EAP_VENDOR_TYPE_UNAUTH_TLS, "UNAUTH-TLS");
365	if (eap == NULL)
366		return -1;
367
368	eap->init = eap_unauth_tls_init;
369	eap->deinit = eap_tls_deinit;
370	eap->process = eap_tls_process;
371	eap->isKeyAvailable = eap_tls_isKeyAvailable;
372	eap->getKey = eap_tls_getKey;
373	eap->get_status = eap_tls_get_status;
374	eap->has_reauth_data = eap_tls_has_reauth_data;
375	eap->deinit_for_reauth = eap_tls_deinit_for_reauth;
376	eap->init_for_reauth = eap_tls_init_for_reauth;
377	eap->get_emsk = eap_tls_get_emsk;
378
379	ret = eap_peer_method_register(eap);
380	if (ret)
381		eap_peer_method_free(eap);
382	return ret;
383}
384#endif /* EAP_UNAUTH_TLS */
385