xref: /freebsd/contrib/wpa/src/eap_server/eap_server_tls.c (revision 98e0ffaefb0f241cda3a72395d3be04192ae0d47)
1 /*
2  * hostapd / EAP-TLS (RFC 2716)
3  * Copyright (c) 2004-2008, 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 "eap_i.h"
13 #include "eap_tls_common.h"
14 #include "crypto/tls.h"
15 
16 
17 static void eap_tls_reset(struct eap_sm *sm, void *priv);
18 
19 
20 struct eap_tls_data {
21 	struct eap_ssl_data ssl;
22 	enum { START, CONTINUE, SUCCESS, FAILURE } state;
23 	int established;
24 	u8 eap_type;
25 };
26 
27 
28 static const char * eap_tls_state_txt(int state)
29 {
30 	switch (state) {
31 	case START:
32 		return "START";
33 	case CONTINUE:
34 		return "CONTINUE";
35 	case SUCCESS:
36 		return "SUCCESS";
37 	case FAILURE:
38 		return "FAILURE";
39 	default:
40 		return "Unknown?!";
41 	}
42 }
43 
44 
45 static void eap_tls_state(struct eap_tls_data *data, int state)
46 {
47 	wpa_printf(MSG_DEBUG, "EAP-TLS: %s -> %s",
48 		   eap_tls_state_txt(data->state),
49 		   eap_tls_state_txt(state));
50 	data->state = state;
51 }
52 
53 
54 static void * eap_tls_init(struct eap_sm *sm)
55 {
56 	struct eap_tls_data *data;
57 
58 	data = os_zalloc(sizeof(*data));
59 	if (data == NULL)
60 		return NULL;
61 	data->state = START;
62 
63 	if (eap_server_tls_ssl_init(sm, &data->ssl, 1)) {
64 		wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
65 		eap_tls_reset(sm, data);
66 		return NULL;
67 	}
68 
69 	data->eap_type = EAP_TYPE_TLS;
70 
71 	return data;
72 }
73 
74 
75 #ifdef EAP_SERVER_UNAUTH_TLS
76 static void * eap_unauth_tls_init(struct eap_sm *sm)
77 {
78 	struct eap_tls_data *data;
79 
80 	data = os_zalloc(sizeof(*data));
81 	if (data == NULL)
82 		return NULL;
83 	data->state = START;
84 
85 	if (eap_server_tls_ssl_init(sm, &data->ssl, 0)) {
86 		wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
87 		eap_tls_reset(sm, data);
88 		return NULL;
89 	}
90 
91 	data->eap_type = EAP_UNAUTH_TLS_TYPE;
92 	return data;
93 }
94 #endif /* EAP_SERVER_UNAUTH_TLS */
95 
96 
97 #ifdef CONFIG_HS20
98 static void * eap_wfa_unauth_tls_init(struct eap_sm *sm)
99 {
100 	struct eap_tls_data *data;
101 
102 	data = os_zalloc(sizeof(*data));
103 	if (data == NULL)
104 		return NULL;
105 	data->state = START;
106 
107 	if (eap_server_tls_ssl_init(sm, &data->ssl, 0)) {
108 		wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
109 		eap_tls_reset(sm, data);
110 		return NULL;
111 	}
112 
113 	data->eap_type = EAP_WFA_UNAUTH_TLS_TYPE;
114 	return data;
115 }
116 #endif /* CONFIG_HS20 */
117 
118 
119 static void eap_tls_reset(struct eap_sm *sm, void *priv)
120 {
121 	struct eap_tls_data *data = priv;
122 	if (data == NULL)
123 		return;
124 	eap_server_tls_ssl_deinit(sm, &data->ssl);
125 	os_free(data);
126 }
127 
128 
129 static struct wpabuf * eap_tls_build_start(struct eap_sm *sm,
130 					   struct eap_tls_data *data, u8 id)
131 {
132 	struct wpabuf *req;
133 
134 	req = eap_tls_msg_alloc(data->eap_type, 1, EAP_CODE_REQUEST, id);
135 	if (req == NULL) {
136 		wpa_printf(MSG_ERROR, "EAP-TLS: Failed to allocate memory for "
137 			   "request");
138 		eap_tls_state(data, FAILURE);
139 		return NULL;
140 	}
141 
142 	wpabuf_put_u8(req, EAP_TLS_FLAGS_START);
143 
144 	eap_tls_state(data, CONTINUE);
145 
146 	return req;
147 }
148 
149 
150 static struct wpabuf * eap_tls_buildReq(struct eap_sm *sm, void *priv, u8 id)
151 {
152 	struct eap_tls_data *data = priv;
153 	struct wpabuf *res;
154 
155 	if (data->ssl.state == FRAG_ACK) {
156 		return eap_server_tls_build_ack(id, data->eap_type, 0);
157 	}
158 
159 	if (data->ssl.state == WAIT_FRAG_ACK) {
160 		res = eap_server_tls_build_msg(&data->ssl, data->eap_type, 0,
161 					       id);
162 		goto check_established;
163 	}
164 
165 	switch (data->state) {
166 	case START:
167 		return eap_tls_build_start(sm, data, id);
168 	case CONTINUE:
169 		if (tls_connection_established(sm->ssl_ctx, data->ssl.conn))
170 			data->established = 1;
171 		break;
172 	default:
173 		wpa_printf(MSG_DEBUG, "EAP-TLS: %s - unexpected state %d",
174 			   __func__, data->state);
175 		return NULL;
176 	}
177 
178 	res = eap_server_tls_build_msg(&data->ssl, data->eap_type, 0, id);
179 
180 check_established:
181 	if (data->established && data->ssl.state != WAIT_FRAG_ACK) {
182 		/* TLS handshake has been completed and there are no more
183 		 * fragments waiting to be sent out. */
184 		wpa_printf(MSG_DEBUG, "EAP-TLS: Done");
185 		eap_tls_state(data, SUCCESS);
186 	}
187 
188 	return res;
189 }
190 
191 
192 static Boolean eap_tls_check(struct eap_sm *sm, void *priv,
193 			     struct wpabuf *respData)
194 {
195 	struct eap_tls_data *data = priv;
196 	const u8 *pos;
197 	size_t len;
198 
199 	if (data->eap_type == EAP_UNAUTH_TLS_TYPE)
200 		pos = eap_hdr_validate(EAP_VENDOR_UNAUTH_TLS,
201 				       EAP_VENDOR_TYPE_UNAUTH_TLS, respData,
202 				       &len);
203 	else if (data->eap_type == EAP_WFA_UNAUTH_TLS_TYPE)
204 		pos = eap_hdr_validate(EAP_VENDOR_WFA_NEW,
205 				       EAP_VENDOR_WFA_UNAUTH_TLS, respData,
206 				       &len);
207 	else
208 		pos = eap_hdr_validate(EAP_VENDOR_IETF, data->eap_type,
209 				       respData, &len);
210 	if (pos == NULL || len < 1) {
211 		wpa_printf(MSG_INFO, "EAP-TLS: Invalid frame");
212 		return TRUE;
213 	}
214 
215 	return FALSE;
216 }
217 
218 
219 static void eap_tls_process_msg(struct eap_sm *sm, void *priv,
220 				const struct wpabuf *respData)
221 {
222 	struct eap_tls_data *data = priv;
223 	if (data->state == SUCCESS && wpabuf_len(data->ssl.tls_in) == 0) {
224 		wpa_printf(MSG_DEBUG, "EAP-TLS: Client acknowledged final TLS "
225 			   "handshake message");
226 		return;
227 	}
228 	if (eap_server_tls_phase1(sm, &data->ssl) < 0)
229 		eap_tls_state(data, FAILURE);
230 }
231 
232 
233 static void eap_tls_process(struct eap_sm *sm, void *priv,
234 			    struct wpabuf *respData)
235 {
236 	struct eap_tls_data *data = priv;
237 	if (eap_server_tls_process(sm, &data->ssl, respData, data,
238 				   data->eap_type, NULL, eap_tls_process_msg) <
239 	    0)
240 		eap_tls_state(data, FAILURE);
241 }
242 
243 
244 static Boolean eap_tls_isDone(struct eap_sm *sm, void *priv)
245 {
246 	struct eap_tls_data *data = priv;
247 	return data->state == SUCCESS || data->state == FAILURE;
248 }
249 
250 
251 static u8 * eap_tls_getKey(struct eap_sm *sm, void *priv, size_t *len)
252 {
253 	struct eap_tls_data *data = priv;
254 	u8 *eapKeyData;
255 
256 	if (data->state != SUCCESS)
257 		return NULL;
258 
259 	eapKeyData = eap_server_tls_derive_key(sm, &data->ssl,
260 					       "client EAP encryption",
261 					       EAP_TLS_KEY_LEN);
262 	if (eapKeyData) {
263 		*len = EAP_TLS_KEY_LEN;
264 		wpa_hexdump(MSG_DEBUG, "EAP-TLS: Derived key",
265 			    eapKeyData, EAP_TLS_KEY_LEN);
266 	} else {
267 		wpa_printf(MSG_DEBUG, "EAP-TLS: Failed to derive key");
268 	}
269 
270 	return eapKeyData;
271 }
272 
273 
274 static u8 * eap_tls_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
275 {
276 	struct eap_tls_data *data = priv;
277 	u8 *eapKeyData, *emsk;
278 
279 	if (data->state != SUCCESS)
280 		return NULL;
281 
282 	eapKeyData = eap_server_tls_derive_key(sm, &data->ssl,
283 					       "client EAP encryption",
284 					       EAP_TLS_KEY_LEN + EAP_EMSK_LEN);
285 	if (eapKeyData) {
286 		emsk = os_malloc(EAP_EMSK_LEN);
287 		if (emsk)
288 			os_memcpy(emsk, eapKeyData + EAP_TLS_KEY_LEN,
289 				  EAP_EMSK_LEN);
290 		bin_clear_free(eapKeyData, EAP_TLS_KEY_LEN + EAP_EMSK_LEN);
291 	} else
292 		emsk = NULL;
293 
294 	if (emsk) {
295 		*len = EAP_EMSK_LEN;
296 		wpa_hexdump(MSG_DEBUG, "EAP-TLS: Derived EMSK",
297 			    emsk, EAP_EMSK_LEN);
298 	} else {
299 		wpa_printf(MSG_DEBUG, "EAP-TLS: Failed to derive EMSK");
300 	}
301 
302 	return emsk;
303 }
304 
305 
306 static Boolean eap_tls_isSuccess(struct eap_sm *sm, void *priv)
307 {
308 	struct eap_tls_data *data = priv;
309 	return data->state == SUCCESS;
310 }
311 
312 
313 static u8 * eap_tls_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
314 {
315 	struct eap_tls_data *data = priv;
316 
317 	if (data->state != SUCCESS)
318 		return NULL;
319 
320 	return eap_server_tls_derive_session_id(sm, &data->ssl, EAP_TYPE_TLS,
321 						len);
322 }
323 
324 
325 int eap_server_tls_register(void)
326 {
327 	struct eap_method *eap;
328 	int ret;
329 
330 	eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
331 				      EAP_VENDOR_IETF, EAP_TYPE_TLS, "TLS");
332 	if (eap == NULL)
333 		return -1;
334 
335 	eap->init = eap_tls_init;
336 	eap->reset = eap_tls_reset;
337 	eap->buildReq = eap_tls_buildReq;
338 	eap->check = eap_tls_check;
339 	eap->process = eap_tls_process;
340 	eap->isDone = eap_tls_isDone;
341 	eap->getKey = eap_tls_getKey;
342 	eap->isSuccess = eap_tls_isSuccess;
343 	eap->get_emsk = eap_tls_get_emsk;
344 	eap->getSessionId = eap_tls_get_session_id;
345 
346 	ret = eap_server_method_register(eap);
347 	if (ret)
348 		eap_server_method_free(eap);
349 	return ret;
350 }
351 
352 
353 #ifdef EAP_SERVER_UNAUTH_TLS
354 int eap_server_unauth_tls_register(void)
355 {
356 	struct eap_method *eap;
357 	int ret;
358 
359 	eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
360 				      EAP_VENDOR_UNAUTH_TLS,
361 				      EAP_VENDOR_TYPE_UNAUTH_TLS,
362 				      "UNAUTH-TLS");
363 	if (eap == NULL)
364 		return -1;
365 
366 	eap->init = eap_unauth_tls_init;
367 	eap->reset = eap_tls_reset;
368 	eap->buildReq = eap_tls_buildReq;
369 	eap->check = eap_tls_check;
370 	eap->process = eap_tls_process;
371 	eap->isDone = eap_tls_isDone;
372 	eap->getKey = eap_tls_getKey;
373 	eap->isSuccess = eap_tls_isSuccess;
374 	eap->get_emsk = eap_tls_get_emsk;
375 
376 	ret = eap_server_method_register(eap);
377 	if (ret)
378 		eap_server_method_free(eap);
379 	return ret;
380 }
381 #endif /* EAP_SERVER_UNAUTH_TLS */
382 
383 
384 #ifdef CONFIG_HS20
385 int eap_server_wfa_unauth_tls_register(void)
386 {
387 	struct eap_method *eap;
388 	int ret;
389 
390 	eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
391 				      EAP_VENDOR_WFA_NEW,
392 				      EAP_VENDOR_WFA_UNAUTH_TLS,
393 				      "WFA-UNAUTH-TLS");
394 	if (eap == NULL)
395 		return -1;
396 
397 	eap->init = eap_wfa_unauth_tls_init;
398 	eap->reset = eap_tls_reset;
399 	eap->buildReq = eap_tls_buildReq;
400 	eap->check = eap_tls_check;
401 	eap->process = eap_tls_process;
402 	eap->isDone = eap_tls_isDone;
403 	eap->getKey = eap_tls_getKey;
404 	eap->isSuccess = eap_tls_isSuccess;
405 	eap->get_emsk = eap_tls_get_emsk;
406 
407 	ret = eap_server_method_register(eap);
408 	if (ret)
409 		eap_server_method_free(eap);
410 	return ret;
411 }
412 #endif /* CONFIG_HS20 */
413