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 "eap_i.h"
19 #include "eap_tls_common.h"
20 #include "eap_config.h"
21 #include "tls.h"
22 
23 
24 static void eap_tls_deinit(struct eap_sm *sm, void *priv);
25 
26 
27 struct eap_tls_data {
28 	struct eap_ssl_data ssl;
29 	u8 *key_data;
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 	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 
71 static 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 
82 static 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 
118 static 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 
143 static 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 
186 static 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 
193 static void eap_tls_deinit_for_reauth(struct eap_sm *sm, void *priv)
194 {
195 }
196 
197 
198 static 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 
211 static 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 
219 static 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 
226 static 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 
245 static 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 
264 int 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