eap_tls.c revision 61d9df3e62aaa0e87ad05452fcb95142159a17b6 
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	void *ssl_ctx;
25	u8 eap_type;
26};
27
28
29static void * eap_tls_init(struct eap_sm *sm)
30{
31	struct eap_tls_data *data;
32	struct eap_peer_config *config = eap_get_config(sm);
33	if (config == NULL ||
34	    ((sm->init_phase2 ? config->private_key2 : config->private_key)
35	     == NULL &&
36	     (sm->init_phase2 ? config->engine2 : config->engine) == 0)) {
37		wpa_printf(MSG_INFO, "EAP-TLS: Private key not configured");
38		return NULL;
39	}
40
41	data = os_zalloc(sizeof(*data));
42	if (data == NULL)
43		return NULL;
44
45	data->ssl_ctx = sm->init_phase2 && sm->ssl_ctx2 ? sm->ssl_ctx2 :
46		sm->ssl_ctx;
47
48	if (eap_peer_tls_ssl_init(sm, &data->ssl, config, EAP_TYPE_TLS)) {
49		wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
50		eap_tls_deinit(sm, data);
51		if (config->engine) {
52			wpa_printf(MSG_DEBUG, "EAP-TLS: Requesting Smartcard "
53				   "PIN");
54			eap_sm_request_pin(sm);
55			sm->ignore = TRUE;
56		} else if (config->private_key && !config->private_key_passwd)
57		{
58			wpa_printf(MSG_DEBUG, "EAP-TLS: Requesting private "
59				   "key passphrase");
60			eap_sm_request_passphrase(sm);
61			sm->ignore = TRUE;
62		}
63		return NULL;
64	}
65
66	data->eap_type = EAP_TYPE_TLS;
67
68	return data;
69}
70
71
72#ifdef EAP_UNAUTH_TLS
73static void * eap_unauth_tls_init(struct eap_sm *sm)
74{
75	struct eap_tls_data *data;
76	struct eap_peer_config *config = eap_get_config(sm);
77
78	data = os_zalloc(sizeof(*data));
79	if (data == NULL)
80		return NULL;
81
82	data->ssl_ctx = sm->init_phase2 && sm->ssl_ctx2 ? sm->ssl_ctx2 :
83		sm->ssl_ctx;
84
85	if (eap_peer_tls_ssl_init(sm, &data->ssl, config,
86				  EAP_UNAUTH_TLS_TYPE)) {
87		wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
88		eap_tls_deinit(sm, data);
89		return NULL;
90	}
91
92	data->eap_type = EAP_UNAUTH_TLS_TYPE;
93
94	return data;
95}
96#endif /* EAP_UNAUTH_TLS */
97
98
99static void eap_tls_deinit(struct eap_sm *sm, void *priv)
100{
101	struct eap_tls_data *data = priv;
102	if (data == NULL)
103		return;
104	eap_peer_tls_ssl_deinit(sm, &data->ssl);
105	os_free(data->key_data);
106	os_free(data);
107}
108
109
110static struct wpabuf * eap_tls_failure(struct eap_sm *sm,
111				       struct eap_tls_data *data,
112				       struct eap_method_ret *ret, int res,
113				       struct wpabuf *resp, u8 id)
114{
115	wpa_printf(MSG_DEBUG, "EAP-TLS: TLS processing failed");
116
117	ret->methodState = METHOD_DONE;
118	ret->decision = DECISION_FAIL;
119
120	if (res == -1) {
121		struct eap_peer_config *config = eap_get_config(sm);
122		if (config) {
123			/*
124			 * The TLS handshake failed. So better forget the old
125			 * PIN. It may be wrong, we cannot be sure but trying
126			 * the wrong one again might block it on the card--so
127			 * better ask the user again.
128			 */
129			os_free(config->pin);
130			config->pin = NULL;
131		}
132	}
133
134	if (resp) {
135		/*
136		 * This is likely an alert message, so send it instead of just
137		 * ACKing the error.
138		 */
139		return resp;
140	}
141
142	return eap_peer_tls_build_ack(id, data->eap_type, 0);
143}
144
145
146static void eap_tls_success(struct eap_sm *sm, struct eap_tls_data *data,
147			    struct eap_method_ret *ret)
148{
149	wpa_printf(MSG_DEBUG, "EAP-TLS: Done");
150
151	ret->methodState = METHOD_DONE;
152	ret->decision = DECISION_UNCOND_SUCC;
153
154	os_free(data->key_data);
155	data->key_data = eap_peer_tls_derive_key(sm, &data->ssl,
156						 "client EAP encryption",
157						 EAP_TLS_KEY_LEN +
158						 EAP_EMSK_LEN);
159	if (data->key_data) {
160		wpa_hexdump_key(MSG_DEBUG, "EAP-TLS: Derived key",
161				data->key_data, EAP_TLS_KEY_LEN);
162		wpa_hexdump_key(MSG_DEBUG, "EAP-TLS: Derived EMSK",
163				data->key_data + EAP_TLS_KEY_LEN,
164				EAP_EMSK_LEN);
165	} else {
166		wpa_printf(MSG_INFO, "EAP-TLS: Failed to derive key");
167	}
168}
169
170
171static struct wpabuf * eap_tls_process(struct eap_sm *sm, void *priv,
172				       struct eap_method_ret *ret,
173				       const struct wpabuf *reqData)
174{
175	size_t left;
176	int res;
177	struct wpabuf *resp;
178	u8 flags, id;
179	const u8 *pos;
180	struct eap_tls_data *data = priv;
181
182	pos = eap_peer_tls_process_init(sm, &data->ssl, data->eap_type, ret,
183					reqData, &left, &flags);
184	if (pos == NULL)
185		return NULL;
186	id = eap_get_id(reqData);
187
188	if (flags & EAP_TLS_FLAGS_START) {
189		wpa_printf(MSG_DEBUG, "EAP-TLS: Start");
190		left = 0; /* make sure that this frame is empty, even though it
191			   * should always be, anyway */
192	}
193
194	resp = NULL;
195	res = eap_peer_tls_process_helper(sm, &data->ssl, data->eap_type, 0,
196					  id, pos, left, &resp);
197
198	if (res < 0) {
199		return eap_tls_failure(sm, data, ret, res, resp, id);
200	}
201
202	if (tls_connection_established(data->ssl_ctx, data->ssl.conn))
203		eap_tls_success(sm, data, ret);
204
205	if (res == 1) {
206		wpabuf_free(resp);
207		return eap_peer_tls_build_ack(id, data->eap_type, 0);
208	}
209
210	return resp;
211}
212
213
214static Boolean eap_tls_has_reauth_data(struct eap_sm *sm, void *priv)
215{
216	struct eap_tls_data *data = priv;
217	return tls_connection_established(data->ssl_ctx, data->ssl.conn);
218}
219
220
221static void eap_tls_deinit_for_reauth(struct eap_sm *sm, void *priv)
222{
223}
224
225
226static void * eap_tls_init_for_reauth(struct eap_sm *sm, void *priv)
227{
228	struct eap_tls_data *data = priv;
229	os_free(data->key_data);
230	data->key_data = NULL;
231	if (eap_peer_tls_reauth_init(sm, &data->ssl)) {
232		os_free(data);
233		return NULL;
234	}
235	return priv;
236}
237
238
239static int eap_tls_get_status(struct eap_sm *sm, void *priv, char *buf,
240			      size_t buflen, int verbose)
241{
242	struct eap_tls_data *data = priv;
243	return eap_peer_tls_status(sm, &data->ssl, buf, buflen, verbose);
244}
245
246
247static Boolean eap_tls_isKeyAvailable(struct eap_sm *sm, void *priv)
248{
249	struct eap_tls_data *data = priv;
250	return data->key_data != NULL;
251}
252
253
254static u8 * eap_tls_getKey(struct eap_sm *sm, void *priv, size_t *len)
255{
256	struct eap_tls_data *data = priv;
257	u8 *key;
258
259	if (data->key_data == NULL)
260		return NULL;
261
262	key = os_malloc(EAP_TLS_KEY_LEN);
263	if (key == NULL)
264		return NULL;
265
266	*len = EAP_TLS_KEY_LEN;
267	os_memcpy(key, data->key_data, EAP_TLS_KEY_LEN);
268
269	return key;
270}
271
272
273static u8 * eap_tls_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
274{
275	struct eap_tls_data *data = priv;
276	u8 *key;
277
278	if (data->key_data == NULL)
279		return NULL;
280
281	key = os_malloc(EAP_EMSK_LEN);
282	if (key == NULL)
283		return NULL;
284
285	*len = EAP_EMSK_LEN;
286	os_memcpy(key, data->key_data + EAP_TLS_KEY_LEN, EAP_EMSK_LEN);
287
288	return key;
289}
290
291
292int eap_peer_tls_register(void)
293{
294	struct eap_method *eap;
295	int ret;
296
297	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
298				    EAP_VENDOR_IETF, EAP_TYPE_TLS, "TLS");
299	if (eap == NULL)
300		return -1;
301
302	eap->init = eap_tls_init;
303	eap->deinit = eap_tls_deinit;
304	eap->process = eap_tls_process;
305	eap->isKeyAvailable = eap_tls_isKeyAvailable;
306	eap->getKey = eap_tls_getKey;
307	eap->get_status = eap_tls_get_status;
308	eap->has_reauth_data = eap_tls_has_reauth_data;
309	eap->deinit_for_reauth = eap_tls_deinit_for_reauth;
310	eap->init_for_reauth = eap_tls_init_for_reauth;
311	eap->get_emsk = eap_tls_get_emsk;
312
313	ret = eap_peer_method_register(eap);
314	if (ret)
315		eap_peer_method_free(eap);
316	return ret;
317}
318
319
320#ifdef EAP_UNAUTH_TLS
321int eap_peer_unauth_tls_register(void)
322{
323	struct eap_method *eap;
324	int ret;
325
326	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
327				    EAP_VENDOR_UNAUTH_TLS,
328				    EAP_VENDOR_TYPE_UNAUTH_TLS, "UNAUTH-TLS");
329	if (eap == NULL)
330		return -1;
331
332	eap->init = eap_unauth_tls_init;
333	eap->deinit = eap_tls_deinit;
334	eap->process = eap_tls_process;
335	eap->isKeyAvailable = eap_tls_isKeyAvailable;
336	eap->getKey = eap_tls_getKey;
337	eap->get_status = eap_tls_get_status;
338	eap->has_reauth_data = eap_tls_has_reauth_data;
339	eap->deinit_for_reauth = eap_tls_deinit_for_reauth;
340	eap->init_for_reauth = eap_tls_init_for_reauth;
341	eap->get_emsk = eap_tls_get_emsk;
342
343	ret = eap_peer_method_register(eap);
344	if (ret)
345		eap_peer_method_free(eap);
346	return ret;
347}
348#endif /* EAP_UNAUTH_TLS */
349