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