eap_server_tls.c revision 281806 
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
17static void eap_tls_reset(struct eap_sm *sm, void *priv);
18
19
20struct 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
28static 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
45static 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
54static 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
76static 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
98static 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
119static 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
129static 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
150static 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
180check_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
192static 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
219static 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
233static 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
244static 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
251static 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
274static 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
306static 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
313static 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
325int 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
354int 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
385int 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