eap_tls.c revision 04949598a23f501be6eec21697465fd46a28840a 
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};
26
27
28static void * eap_tls_init(struct eap_sm *sm)
29{
30	struct eap_tls_data *data;
31	struct eap_peer_config *config = eap_get_config(sm);
32	if (config == NULL ||
33	    ((sm->init_phase2 ? config->private_key2 : config->private_key)
34	     == NULL &&
35	     (sm->init_phase2 ? config->engine2 : config->engine) == 0)) {
36		wpa_printf(MSG_INFO, "EAP-TLS: Private key not configured");
37		return NULL;
38	}
39
40	data = os_zalloc(sizeof(*data));
41	if (data == NULL)
42		return NULL;
43
44	data->ssl_ctx = sm->init_phase2 && sm->ssl_ctx2 ? sm->ssl_ctx2 :
45		sm->ssl_ctx;
46
47	if (eap_peer_tls_ssl_init(sm, &data->ssl, config)) {
48		wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
49		eap_tls_deinit(sm, data);
50		if (config->engine) {
51			wpa_printf(MSG_DEBUG, "EAP-TLS: Requesting Smartcard "
52				   "PIN");
53			eap_sm_request_pin(sm);
54			sm->ignore = TRUE;
55		} else if (config->private_key && !config->private_key_passwd)
56		{
57			wpa_printf(MSG_DEBUG, "EAP-TLS: Requesting private "
58				   "key passphrase");
59			eap_sm_request_passphrase(sm);
60			sm->ignore = TRUE;
61		}
62		return NULL;
63	}
64
65	return data;
66}
67
68
69static void eap_tls_deinit(struct eap_sm *sm, void *priv)
70{
71	struct eap_tls_data *data = priv;
72	if (data == NULL)
73		return;
74	eap_peer_tls_ssl_deinit(sm, &data->ssl);
75	os_free(data->key_data);
76	os_free(data);
77}
78
79
80static struct wpabuf * eap_tls_failure(struct eap_sm *sm,
81				       struct eap_tls_data *data,
82				       struct eap_method_ret *ret, int res,
83				       struct wpabuf *resp, u8 id)
84{
85	wpa_printf(MSG_DEBUG, "EAP-TLS: TLS processing failed");
86
87	ret->methodState = METHOD_DONE;
88	ret->decision = DECISION_FAIL;
89
90	if (res == -1) {
91		struct eap_peer_config *config = eap_get_config(sm);
92		if (config) {
93			/*
94			 * The TLS handshake failed. So better forget the old
95			 * PIN. It may be wrong, we cannot be sure but trying
96			 * the wrong one again might block it on the card--so
97			 * better ask the user again.
98			 */
99			os_free(config->pin);
100			config->pin = NULL;
101		}
102	}
103
104	if (resp) {
105		/*
106		 * This is likely an alert message, so send it instead of just
107		 * ACKing the error.
108		 */
109		return resp;
110	}
111
112	return eap_peer_tls_build_ack(id, EAP_TYPE_TLS, 0);
113}
114
115
116static void eap_tls_success(struct eap_sm *sm, struct eap_tls_data *data,
117			    struct eap_method_ret *ret)
118{
119	wpa_printf(MSG_DEBUG, "EAP-TLS: Done");
120
121	ret->methodState = METHOD_DONE;
122	ret->decision = DECISION_UNCOND_SUCC;
123
124	os_free(data->key_data);
125	data->key_data = eap_peer_tls_derive_key(sm, &data->ssl,
126						 "client EAP encryption",
127						 EAP_TLS_KEY_LEN +
128						 EAP_EMSK_LEN);
129	if (data->key_data) {
130		wpa_hexdump_key(MSG_DEBUG, "EAP-TLS: Derived key",
131				data->key_data, EAP_TLS_KEY_LEN);
132		wpa_hexdump_key(MSG_DEBUG, "EAP-TLS: Derived EMSK",
133				data->key_data + EAP_TLS_KEY_LEN,
134				EAP_EMSK_LEN);
135	} else {
136		wpa_printf(MSG_INFO, "EAP-TLS: Failed to derive key");
137	}
138}
139
140
141static struct wpabuf * eap_tls_process(struct eap_sm *sm, void *priv,
142				       struct eap_method_ret *ret,
143				       const struct wpabuf *reqData)
144{
145	size_t left;
146	int res;
147	struct wpabuf *resp;
148	u8 flags, id;
149	const u8 *pos;
150	struct eap_tls_data *data = priv;
151
152	pos = eap_peer_tls_process_init(sm, &data->ssl, EAP_TYPE_TLS, ret,
153					reqData, &left, &flags);
154	if (pos == NULL)
155		return NULL;
156	id = eap_get_id(reqData);
157
158	if (flags & EAP_TLS_FLAGS_START) {
159		wpa_printf(MSG_DEBUG, "EAP-TLS: Start");
160		left = 0; /* make sure that this frame is empty, even though it
161			   * should always be, anyway */
162	}
163
164	resp = NULL;
165	res = eap_peer_tls_process_helper(sm, &data->ssl, EAP_TYPE_TLS, 0, id,
166					  pos, left, &resp);
167
168	if (res < 0) {
169		return eap_tls_failure(sm, data, ret, res, resp, id);
170	}
171
172	if (tls_connection_established(data->ssl_ctx, data->ssl.conn))
173		eap_tls_success(sm, data, ret);
174
175	if (res == 1) {
176		wpabuf_free(resp);
177		return eap_peer_tls_build_ack(id, EAP_TYPE_TLS, 0);
178	}
179
180	return resp;
181}
182
183
184static Boolean eap_tls_has_reauth_data(struct eap_sm *sm, void *priv)
185{
186	struct eap_tls_data *data = priv;
187	return tls_connection_established(data->ssl_ctx, data->ssl.conn);
188}
189
190
191static void eap_tls_deinit_for_reauth(struct eap_sm *sm, void *priv)
192{
193}
194
195
196static void * eap_tls_init_for_reauth(struct eap_sm *sm, void *priv)
197{
198	struct eap_tls_data *data = priv;
199	os_free(data->key_data);
200	data->key_data = NULL;
201	if (eap_peer_tls_reauth_init(sm, &data->ssl)) {
202		os_free(data);
203		return NULL;
204	}
205	return priv;
206}
207
208
209static int eap_tls_get_status(struct eap_sm *sm, void *priv, char *buf,
210			      size_t buflen, int verbose)
211{
212	struct eap_tls_data *data = priv;
213	return eap_peer_tls_status(sm, &data->ssl, buf, buflen, verbose);
214}
215
216
217static Boolean eap_tls_isKeyAvailable(struct eap_sm *sm, void *priv)
218{
219	struct eap_tls_data *data = priv;
220	return data->key_data != NULL;
221}
222
223
224static u8 * eap_tls_getKey(struct eap_sm *sm, void *priv, size_t *len)
225{
226	struct eap_tls_data *data = priv;
227	u8 *key;
228
229	if (data->key_data == NULL)
230		return NULL;
231
232	key = os_malloc(EAP_TLS_KEY_LEN);
233	if (key == NULL)
234		return NULL;
235
236	*len = EAP_TLS_KEY_LEN;
237	os_memcpy(key, data->key_data, EAP_TLS_KEY_LEN);
238
239	return key;
240}
241
242
243static u8 * eap_tls_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
244{
245	struct eap_tls_data *data = priv;
246	u8 *key;
247
248	if (data->key_data == NULL)
249		return NULL;
250
251	key = os_malloc(EAP_EMSK_LEN);
252	if (key == NULL)
253		return NULL;
254
255	*len = EAP_EMSK_LEN;
256	os_memcpy(key, data->key_data + EAP_TLS_KEY_LEN, EAP_EMSK_LEN);
257
258	return key;
259}
260
261
262int eap_peer_tls_register(void)
263{
264	struct eap_method *eap;
265	int ret;
266
267	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
268				    EAP_VENDOR_IETF, EAP_TYPE_TLS, "TLS");
269	if (eap == NULL)
270		return -1;
271
272	eap->init = eap_tls_init;
273	eap->deinit = eap_tls_deinit;
274	eap->process = eap_tls_process;
275	eap->isKeyAvailable = eap_tls_isKeyAvailable;
276	eap->getKey = eap_tls_getKey;
277	eap->get_status = eap_tls_get_status;
278	eap->has_reauth_data = eap_tls_has_reauth_data;
279	eap->deinit_for_reauth = eap_tls_deinit_for_reauth;
280	eap->init_for_reauth = eap_tls_init_for_reauth;
281	eap->get_emsk = eap_tls_get_emsk;
282
283	ret = eap_peer_method_register(eap);
284	if (ret)
285		eap_peer_method_free(eap);
286	return ret;
287}
288