eap_tls.c revision 8d520ff1dc2da35cdca849e982051b86468016d8 
1/*
2 * EAP peer method: EAP-TLS (RFC 2716)
3 * Copyright (c) 2004-2008, Jouni Malinen <j@w1.fi>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * Alternatively, this software may be distributed under the terms of BSD
10 * license.
11 *
12 * See README and COPYING for more details.
13 */
14
15#include "includes.h"
16
17#include "common.h"
18#include "crypto/tls.h"
19#include "eap_i.h"
20#include "eap_tls_common.h"
21#include "eap_config.h"
22
23
24static void eap_tls_deinit(struct eap_sm *sm, void *priv);
25
26
27struct eap_tls_data {
28	struct eap_ssl_data ssl;
29	u8 *key_data;
30};
31
32
33static 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	if (config == NULL ||
38	    ((sm->init_phase2 ? config->private_key2 : config->private_key)
39	     == NULL &&
40	     (sm->init_phase2 ? config->engine2 : config->engine) == 0)) {
41		wpa_printf(MSG_INFO, "EAP-TLS: Private key not configured");
42		return NULL;
43	}
44
45	data = os_zalloc(sizeof(*data));
46	if (data == NULL)
47		return NULL;
48
49	if (eap_peer_tls_ssl_init(sm, &data->ssl, config)) {
50		wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
51		eap_tls_deinit(sm, data);
52		if (config->engine) {
53			wpa_printf(MSG_DEBUG, "EAP-TLS: Requesting Smartcard "
54				   "PIN");
55			eap_sm_request_pin(sm);
56			sm->ignore = TRUE;
57		} else if (config->private_key && !config->private_key_passwd)
58		{
59			wpa_printf(MSG_DEBUG, "EAP-TLS: Requesting private "
60				   "key passphrase");
61			eap_sm_request_passphrase(sm);
62			sm->ignore = TRUE;
63		}
64		return NULL;
65	}
66
67	return data;
68}
69
70
71static void eap_tls_deinit(struct eap_sm *sm, void *priv)
72{
73	struct eap_tls_data *data = priv;
74	if (data == NULL)
75		return;
76	eap_peer_tls_ssl_deinit(sm, &data->ssl);
77	os_free(data->key_data);
78	os_free(data);
79}
80
81
82static struct wpabuf * eap_tls_failure(struct eap_sm *sm,
83				       struct eap_tls_data *data,
84				       struct eap_method_ret *ret, int res,
85				       struct wpabuf *resp, u8 id)
86{
87	wpa_printf(MSG_DEBUG, "EAP-TLS: TLS processing failed");
88
89	ret->methodState = METHOD_DONE;
90	ret->decision = DECISION_FAIL;
91
92	if (res == -1) {
93		struct eap_peer_config *config = eap_get_config(sm);
94		if (config) {
95			/*
96			 * The TLS handshake failed. So better forget the old
97			 * PIN. It may be wrong, we cannot be sure but trying
98			 * the wrong one again might block it on the card--so
99			 * better ask the user again.
100			 */
101			os_free(config->pin);
102			config->pin = NULL;
103		}
104	}
105
106	if (resp) {
107		/*
108		 * This is likely an alert message, so send it instead of just
109		 * ACKing the error.
110		 */
111		return resp;
112	}
113
114	return eap_peer_tls_build_ack(id, EAP_TYPE_TLS, 0);
115}
116
117
118static void eap_tls_success(struct eap_sm *sm, struct eap_tls_data *data,
119			    struct eap_method_ret *ret)
120{
121	wpa_printf(MSG_DEBUG, "EAP-TLS: Done");
122
123	ret->methodState = METHOD_DONE;
124	ret->decision = DECISION_UNCOND_SUCC;
125
126	os_free(data->key_data);
127	data->key_data = eap_peer_tls_derive_key(sm, &data->ssl,
128						 "client EAP encryption",
129						 EAP_TLS_KEY_LEN +
130						 EAP_EMSK_LEN);
131	if (data->key_data) {
132		wpa_hexdump_key(MSG_DEBUG, "EAP-TLS: Derived key",
133				data->key_data, EAP_TLS_KEY_LEN);
134		wpa_hexdump_key(MSG_DEBUG, "EAP-TLS: Derived EMSK",
135				data->key_data + EAP_TLS_KEY_LEN,
136				EAP_EMSK_LEN);
137	} else {
138		wpa_printf(MSG_INFO, "EAP-TLS: Failed to derive key");
139	}
140}
141
142
143static struct wpabuf * eap_tls_process(struct eap_sm *sm, void *priv,
144				       struct eap_method_ret *ret,
145				       const struct wpabuf *reqData)
146{
147	size_t left;
148	int res;
149	struct wpabuf *resp;
150	u8 flags, id;
151	const u8 *pos;
152	struct eap_tls_data *data = priv;
153
154	pos = eap_peer_tls_process_init(sm, &data->ssl, EAP_TYPE_TLS, ret,
155					reqData, &left, &flags);
156	if (pos == NULL)
157		return NULL;
158	id = eap_get_id(reqData);
159
160	if (flags & EAP_TLS_FLAGS_START) {
161		wpa_printf(MSG_DEBUG, "EAP-TLS: Start");
162		left = 0; /* make sure that this frame is empty, even though it
163			   * should always be, anyway */
164	}
165
166	resp = NULL;
167	res = eap_peer_tls_process_helper(sm, &data->ssl, EAP_TYPE_TLS, 0, id,
168					  pos, left, &resp);
169
170	if (res < 0) {
171		return eap_tls_failure(sm, data, ret, res, resp, id);
172	}
173
174	if (tls_connection_established(sm->ssl_ctx, data->ssl.conn))
175		eap_tls_success(sm, data, ret);
176
177	if (res == 1) {
178		wpabuf_free(resp);
179		return eap_peer_tls_build_ack(id, EAP_TYPE_TLS, 0);
180	}
181
182	return resp;
183}
184
185
186static Boolean eap_tls_has_reauth_data(struct eap_sm *sm, void *priv)
187{
188	struct eap_tls_data *data = priv;
189	return tls_connection_established(sm->ssl_ctx, data->ssl.conn);
190}
191
192
193static void eap_tls_deinit_for_reauth(struct eap_sm *sm, void *priv)
194{
195}
196
197
198static void * eap_tls_init_for_reauth(struct eap_sm *sm, void *priv)
199{
200	struct eap_tls_data *data = priv;
201	os_free(data->key_data);
202	data->key_data = NULL;
203	if (eap_peer_tls_reauth_init(sm, &data->ssl)) {
204		os_free(data);
205		return NULL;
206	}
207	return priv;
208}
209
210
211static int eap_tls_get_status(struct eap_sm *sm, void *priv, char *buf,
212			      size_t buflen, int verbose)
213{
214	struct eap_tls_data *data = priv;
215	return eap_peer_tls_status(sm, &data->ssl, buf, buflen, verbose);
216}
217
218
219static Boolean eap_tls_isKeyAvailable(struct eap_sm *sm, void *priv)
220{
221	struct eap_tls_data *data = priv;
222	return data->key_data != NULL;
223}
224
225
226static u8 * eap_tls_getKey(struct eap_sm *sm, void *priv, size_t *len)
227{
228	struct eap_tls_data *data = priv;
229	u8 *key;
230
231	if (data->key_data == NULL)
232		return NULL;
233
234	key = os_malloc(EAP_TLS_KEY_LEN);
235	if (key == NULL)
236		return NULL;
237
238	*len = EAP_TLS_KEY_LEN;
239	os_memcpy(key, data->key_data, EAP_TLS_KEY_LEN);
240
241	return key;
242}
243
244
245static u8 * eap_tls_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
246{
247	struct eap_tls_data *data = priv;
248	u8 *key;
249
250	if (data->key_data == NULL)
251		return NULL;
252
253	key = os_malloc(EAP_EMSK_LEN);
254	if (key == NULL)
255		return NULL;
256
257	*len = EAP_EMSK_LEN;
258	os_memcpy(key, data->key_data + EAP_TLS_KEY_LEN, EAP_EMSK_LEN);
259
260	return key;
261}
262
263
264int eap_peer_tls_register(void)
265{
266	struct eap_method *eap;
267	int ret;
268
269	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
270				    EAP_VENDOR_IETF, EAP_TYPE_TLS, "TLS");
271	if (eap == NULL)
272		return -1;
273
274	eap->init = eap_tls_init;
275	eap->deinit = eap_tls_deinit;
276	eap->process = eap_tls_process;
277	eap->isKeyAvailable = eap_tls_isKeyAvailable;
278	eap->getKey = eap_tls_getKey;
279	eap->get_status = eap_tls_get_status;
280	eap->has_reauth_data = eap_tls_has_reauth_data;
281	eap->deinit_for_reauth = eap_tls_deinit_for_reauth;
282	eap->init_for_reauth = eap_tls_init_for_reauth;
283	eap->get_emsk = eap_tls_get_emsk;
284
285	ret = eap_peer_method_register(eap);
286	if (ret)
287		eap_peer_method_free(eap);
288	return ret;
289}
290