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 int phase2;
26 };
27
28
eap_tls_state_txt(int state)29 static const char * eap_tls_state_txt(int state)
30 {
31 switch (state) {
32 case START:
33 return "START";
34 case CONTINUE:
35 return "CONTINUE";
36 case SUCCESS:
37 return "SUCCESS";
38 case FAILURE:
39 return "FAILURE";
40 default:
41 return "Unknown?!";
42 }
43 }
44
45
eap_tls_state(struct eap_tls_data * data,int state)46 static void eap_tls_state(struct eap_tls_data *data, int state)
47 {
48 wpa_printf(MSG_DEBUG, "EAP-TLS: %s -> %s",
49 eap_tls_state_txt(data->state),
50 eap_tls_state_txt(state));
51 data->state = state;
52 if (state == FAILURE)
53 tls_connection_remove_session(data->ssl.conn);
54 }
55
56
eap_tls_valid_session(struct eap_sm * sm,struct eap_tls_data * data)57 static void eap_tls_valid_session(struct eap_sm *sm, struct eap_tls_data *data)
58 {
59 struct wpabuf *buf;
60
61 if (!sm->tls_session_lifetime)
62 return;
63
64 buf = wpabuf_alloc(1);
65 if (!buf)
66 return;
67 wpabuf_put_u8(buf, data->eap_type);
68 tls_connection_set_success_data(data->ssl.conn, buf);
69 }
70
71
eap_tls_init(struct eap_sm * sm)72 static void * eap_tls_init(struct eap_sm *sm)
73 {
74 struct eap_tls_data *data;
75
76 data = os_zalloc(sizeof(*data));
77 if (data == NULL)
78 return NULL;
79 data->state = START;
80
81 if (eap_server_tls_ssl_init(sm, &data->ssl, 1, EAP_TYPE_TLS)) {
82 wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
83 eap_tls_reset(sm, data);
84 return NULL;
85 }
86
87 data->eap_type = EAP_TYPE_TLS;
88
89 data->phase2 = sm->init_phase2;
90
91 return data;
92 }
93
94
95 #ifdef EAP_SERVER_UNAUTH_TLS
eap_unauth_tls_init(struct eap_sm * sm)96 static void * eap_unauth_tls_init(struct eap_sm *sm)
97 {
98 struct eap_tls_data *data;
99
100 data = os_zalloc(sizeof(*data));
101 if (data == NULL)
102 return NULL;
103 data->state = START;
104
105 if (eap_server_tls_ssl_init(sm, &data->ssl, 0, EAP_UNAUTH_TLS_TYPE)) {
106 wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
107 eap_tls_reset(sm, data);
108 return NULL;
109 }
110
111 data->eap_type = EAP_UNAUTH_TLS_TYPE;
112 return data;
113 }
114 #endif /* EAP_SERVER_UNAUTH_TLS */
115
116
117 #ifdef CONFIG_HS20
eap_wfa_unauth_tls_init(struct eap_sm * sm)118 static void * eap_wfa_unauth_tls_init(struct eap_sm *sm)
119 {
120 struct eap_tls_data *data;
121
122 data = os_zalloc(sizeof(*data));
123 if (data == NULL)
124 return NULL;
125 data->state = START;
126
127 if (eap_server_tls_ssl_init(sm, &data->ssl, 0,
128 EAP_WFA_UNAUTH_TLS_TYPE)) {
129 wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
130 eap_tls_reset(sm, data);
131 return NULL;
132 }
133
134 data->eap_type = EAP_WFA_UNAUTH_TLS_TYPE;
135 return data;
136 }
137 #endif /* CONFIG_HS20 */
138
139
eap_tls_reset(struct eap_sm * sm,void * priv)140 static void eap_tls_reset(struct eap_sm *sm, void *priv)
141 {
142 struct eap_tls_data *data = priv;
143 if (data == NULL)
144 return;
145 eap_server_tls_ssl_deinit(sm, &data->ssl);
146 os_free(data);
147 }
148
149
eap_tls_build_start(struct eap_sm * sm,struct eap_tls_data * data,u8 id)150 static struct wpabuf * eap_tls_build_start(struct eap_sm *sm,
151 struct eap_tls_data *data, u8 id)
152 {
153 struct wpabuf *req;
154
155 req = eap_tls_msg_alloc(data->eap_type, 1, EAP_CODE_REQUEST, id);
156 if (req == NULL) {
157 wpa_printf(MSG_ERROR, "EAP-TLS: Failed to allocate memory for "
158 "request");
159 eap_tls_state(data, FAILURE);
160 return NULL;
161 }
162
163 wpabuf_put_u8(req, EAP_TLS_FLAGS_START);
164
165 eap_tls_state(data, CONTINUE);
166
167 return req;
168 }
169
170
eap_tls_buildReq(struct eap_sm * sm,void * priv,u8 id)171 static struct wpabuf * eap_tls_buildReq(struct eap_sm *sm, void *priv, u8 id)
172 {
173 struct eap_tls_data *data = priv;
174 struct wpabuf *res;
175
176 if (data->ssl.state == FRAG_ACK) {
177 return eap_server_tls_build_ack(id, data->eap_type, 0);
178 }
179
180 if (data->ssl.state == WAIT_FRAG_ACK) {
181 res = eap_server_tls_build_msg(&data->ssl, data->eap_type, 0,
182 id);
183 goto check_established;
184 }
185
186 switch (data->state) {
187 case START:
188 return eap_tls_build_start(sm, data, id);
189 case CONTINUE:
190 if (tls_connection_established(sm->ssl_ctx, data->ssl.conn))
191 data->established = 1;
192 break;
193 default:
194 wpa_printf(MSG_DEBUG, "EAP-TLS: %s - unexpected state %d",
195 __func__, data->state);
196 return NULL;
197 }
198
199 res = eap_server_tls_build_msg(&data->ssl, data->eap_type, 0, id);
200
201 check_established:
202 if (data->established && data->ssl.state != WAIT_FRAG_ACK) {
203 /* TLS handshake has been completed and there are no more
204 * fragments waiting to be sent out. */
205 wpa_printf(MSG_DEBUG, "EAP-TLS: Done");
206 eap_tls_state(data, SUCCESS);
207 eap_tls_valid_session(sm, data);
208 if (sm->serial_num) {
209 char user[128];
210 int user_len;
211
212 user_len = os_snprintf(user, sizeof(user), "cert-%s",
213 sm->serial_num);
214 if (eap_user_get(sm, (const u8 *) user, user_len,
215 data->phase2) < 0)
216 wpa_printf(MSG_DEBUG,
217 "EAP-TLS: No user entry found based on the serial number of the client certificate ");
218 else
219 wpa_printf(MSG_DEBUG,
220 "EAP-TLS: Updated user entry based on the serial number of the client certificate ");
221 }
222 }
223
224 return res;
225 }
226
227
eap_tls_check(struct eap_sm * sm,void * priv,struct wpabuf * respData)228 static Boolean eap_tls_check(struct eap_sm *sm, void *priv,
229 struct wpabuf *respData)
230 {
231 struct eap_tls_data *data = priv;
232 const u8 *pos;
233 size_t len;
234
235 if (data->eap_type == EAP_UNAUTH_TLS_TYPE)
236 pos = eap_hdr_validate(EAP_VENDOR_UNAUTH_TLS,
237 EAP_VENDOR_TYPE_UNAUTH_TLS, respData,
238 &len);
239 else if (data->eap_type == EAP_WFA_UNAUTH_TLS_TYPE)
240 pos = eap_hdr_validate(EAP_VENDOR_WFA_NEW,
241 EAP_VENDOR_WFA_UNAUTH_TLS, respData,
242 &len);
243 else
244 pos = eap_hdr_validate(EAP_VENDOR_IETF, data->eap_type,
245 respData, &len);
246 if (pos == NULL || len < 1) {
247 wpa_printf(MSG_INFO, "EAP-TLS: Invalid frame");
248 return TRUE;
249 }
250
251 return FALSE;
252 }
253
254
eap_tls_process_msg(struct eap_sm * sm,void * priv,const struct wpabuf * respData)255 static void eap_tls_process_msg(struct eap_sm *sm, void *priv,
256 const struct wpabuf *respData)
257 {
258 struct eap_tls_data *data = priv;
259 if (data->state == SUCCESS && wpabuf_len(data->ssl.tls_in) == 0) {
260 wpa_printf(MSG_DEBUG, "EAP-TLS: Client acknowledged final TLS "
261 "handshake message");
262 return;
263 }
264 if (eap_server_tls_phase1(sm, &data->ssl) < 0)
265 eap_tls_state(data, FAILURE);
266 }
267
268
eap_tls_process(struct eap_sm * sm,void * priv,struct wpabuf * respData)269 static void eap_tls_process(struct eap_sm *sm, void *priv,
270 struct wpabuf *respData)
271 {
272 struct eap_tls_data *data = priv;
273 const struct wpabuf *buf;
274 const u8 *pos;
275
276 if (eap_server_tls_process(sm, &data->ssl, respData, data,
277 data->eap_type, NULL, eap_tls_process_msg) <
278 0) {
279 eap_tls_state(data, FAILURE);
280 return;
281 }
282
283 if (!tls_connection_established(sm->ssl_ctx, data->ssl.conn) ||
284 !tls_connection_resumed(sm->ssl_ctx, data->ssl.conn))
285 return;
286
287 buf = tls_connection_get_success_data(data->ssl.conn);
288 if (!buf || wpabuf_len(buf) < 1) {
289 wpa_printf(MSG_DEBUG,
290 "EAP-TLS: No success data in resumed session - reject attempt");
291 eap_tls_state(data, FAILURE);
292 return;
293 }
294
295 pos = wpabuf_head(buf);
296 if (*pos != data->eap_type) {
297 wpa_printf(MSG_DEBUG,
298 "EAP-TLS: Resumed session for another EAP type (%u) - reject attempt",
299 *pos);
300 eap_tls_state(data, FAILURE);
301 return;
302 }
303
304 wpa_printf(MSG_DEBUG,
305 "EAP-TLS: Resuming previous session");
306 eap_tls_state(data, SUCCESS);
307 tls_connection_set_success_data_resumed(data->ssl.conn);
308 /* TODO: Cache serial number with session and update EAP user
309 * information based on the cached serial number */
310 }
311
312
eap_tls_isDone(struct eap_sm * sm,void * priv)313 static Boolean eap_tls_isDone(struct eap_sm *sm, void *priv)
314 {
315 struct eap_tls_data *data = priv;
316 return data->state == SUCCESS || data->state == FAILURE;
317 }
318
319
eap_tls_getKey(struct eap_sm * sm,void * priv,size_t * len)320 static u8 * eap_tls_getKey(struct eap_sm *sm, void *priv, size_t *len)
321 {
322 struct eap_tls_data *data = priv;
323 u8 *eapKeyData;
324 const char *label;
325
326 if (data->state != SUCCESS)
327 return NULL;
328
329 if (data->ssl.tls_v13)
330 label = "EXPORTER_EAP_TLS_Key_Material";
331 else
332 label = "client EAP encryption";
333 eapKeyData = eap_server_tls_derive_key(sm, &data->ssl, label,
334 NULL, 0,
335 EAP_TLS_KEY_LEN + EAP_EMSK_LEN);
336 if (eapKeyData) {
337 *len = EAP_TLS_KEY_LEN;
338 wpa_hexdump(MSG_DEBUG, "EAP-TLS: Derived key",
339 eapKeyData, EAP_TLS_KEY_LEN);
340 os_memset(eapKeyData + EAP_TLS_KEY_LEN, 0, EAP_EMSK_LEN);
341 } else {
342 wpa_printf(MSG_DEBUG, "EAP-TLS: Failed to derive key");
343 }
344
345 return eapKeyData;
346 }
347
348
eap_tls_get_emsk(struct eap_sm * sm,void * priv,size_t * len)349 static u8 * eap_tls_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
350 {
351 struct eap_tls_data *data = priv;
352 u8 *eapKeyData, *emsk;
353 const char *label;
354
355 if (data->state != SUCCESS)
356 return NULL;
357
358 if (data->ssl.tls_v13)
359 label = "EXPORTER_EAP_TLS_Key_Material";
360 else
361 label = "client EAP encryption";
362 eapKeyData = eap_server_tls_derive_key(sm, &data->ssl, label,
363 NULL, 0,
364 EAP_TLS_KEY_LEN + EAP_EMSK_LEN);
365 if (eapKeyData) {
366 emsk = os_malloc(EAP_EMSK_LEN);
367 if (emsk)
368 os_memcpy(emsk, eapKeyData + EAP_TLS_KEY_LEN,
369 EAP_EMSK_LEN);
370 bin_clear_free(eapKeyData, EAP_TLS_KEY_LEN + EAP_EMSK_LEN);
371 } else
372 emsk = NULL;
373
374 if (emsk) {
375 *len = EAP_EMSK_LEN;
376 wpa_hexdump(MSG_DEBUG, "EAP-TLS: Derived EMSK",
377 emsk, EAP_EMSK_LEN);
378 } else {
379 wpa_printf(MSG_DEBUG, "EAP-TLS: Failed to derive EMSK");
380 }
381
382 return emsk;
383 }
384
385
eap_tls_isSuccess(struct eap_sm * sm,void * priv)386 static Boolean eap_tls_isSuccess(struct eap_sm *sm, void *priv)
387 {
388 struct eap_tls_data *data = priv;
389 return data->state == SUCCESS;
390 }
391
392
eap_tls_get_session_id(struct eap_sm * sm,void * priv,size_t * len)393 static u8 * eap_tls_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
394 {
395 struct eap_tls_data *data = priv;
396
397 if (data->state != SUCCESS)
398 return NULL;
399
400 return eap_server_tls_derive_session_id(sm, &data->ssl, EAP_TYPE_TLS,
401 len);
402 }
403
404
eap_server_tls_register(void)405 int eap_server_tls_register(void)
406 {
407 struct eap_method *eap;
408
409 eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
410 EAP_VENDOR_IETF, EAP_TYPE_TLS, "TLS");
411 if (eap == NULL)
412 return -1;
413
414 eap->init = eap_tls_init;
415 eap->reset = eap_tls_reset;
416 eap->buildReq = eap_tls_buildReq;
417 eap->check = eap_tls_check;
418 eap->process = eap_tls_process;
419 eap->isDone = eap_tls_isDone;
420 eap->getKey = eap_tls_getKey;
421 eap->isSuccess = eap_tls_isSuccess;
422 eap->get_emsk = eap_tls_get_emsk;
423 eap->getSessionId = eap_tls_get_session_id;
424
425 return eap_server_method_register(eap);
426 }
427
428
429 #ifdef EAP_SERVER_UNAUTH_TLS
eap_server_unauth_tls_register(void)430 int eap_server_unauth_tls_register(void)
431 {
432 struct eap_method *eap;
433
434 eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
435 EAP_VENDOR_UNAUTH_TLS,
436 EAP_VENDOR_TYPE_UNAUTH_TLS,
437 "UNAUTH-TLS");
438 if (eap == NULL)
439 return -1;
440
441 eap->init = eap_unauth_tls_init;
442 eap->reset = eap_tls_reset;
443 eap->buildReq = eap_tls_buildReq;
444 eap->check = eap_tls_check;
445 eap->process = eap_tls_process;
446 eap->isDone = eap_tls_isDone;
447 eap->getKey = eap_tls_getKey;
448 eap->isSuccess = eap_tls_isSuccess;
449 eap->get_emsk = eap_tls_get_emsk;
450
451 return eap_server_method_register(eap);
452 }
453 #endif /* EAP_SERVER_UNAUTH_TLS */
454
455
456 #ifdef CONFIG_HS20
eap_server_wfa_unauth_tls_register(void)457 int eap_server_wfa_unauth_tls_register(void)
458 {
459 struct eap_method *eap;
460
461 eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
462 EAP_VENDOR_WFA_NEW,
463 EAP_VENDOR_WFA_UNAUTH_TLS,
464 "WFA-UNAUTH-TLS");
465 if (eap == NULL)
466 return -1;
467
468 eap->init = eap_wfa_unauth_tls_init;
469 eap->reset = eap_tls_reset;
470 eap->buildReq = eap_tls_buildReq;
471 eap->check = eap_tls_check;
472 eap->process = eap_tls_process;
473 eap->isDone = eap_tls_isDone;
474 eap->getKey = eap_tls_getKey;
475 eap->isSuccess = eap_tls_isSuccess;
476 eap->get_emsk = eap_tls_get_emsk;
477
478 return eap_server_method_register(eap);
479 }
480 #endif /* CONFIG_HS20 */
481