1 /*
2  * EAP peer: EAP-TLS/PEAP/TTLS/FAST common functions
3  * Copyright (c) 2004-2013, 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 "crypto/sha1.h"
13 #include "crypto/tls.h"
14 #include "eap_i.h"
15 #include "eap_tls_common.h"
16 #include "eap_config.h"
17 
18 
eap_tls_msg_alloc(EapType type,size_t payload_len,u8 code,u8 identifier)19 static struct wpabuf * eap_tls_msg_alloc(EapType type, size_t payload_len,
20 					 u8 code, u8 identifier)
21 {
22 	if (type == EAP_UNAUTH_TLS_TYPE)
23 		return eap_msg_alloc(EAP_VENDOR_UNAUTH_TLS,
24 				     EAP_VENDOR_TYPE_UNAUTH_TLS, payload_len,
25 				     code, identifier);
26 	if (type == EAP_WFA_UNAUTH_TLS_TYPE)
27 		return eap_msg_alloc(EAP_VENDOR_WFA_NEW,
28 				     EAP_VENDOR_WFA_UNAUTH_TLS, payload_len,
29 				     code, identifier);
30 	return eap_msg_alloc(EAP_VENDOR_IETF, type, payload_len, code,
31 			     identifier);
32 }
33 
34 
eap_tls_check_blob(struct eap_sm * sm,const char ** name,const u8 ** data,size_t * data_len)35 static int eap_tls_check_blob(struct eap_sm *sm, const char **name,
36 			      const u8 **data, size_t *data_len)
37 {
38 	const struct wpa_config_blob *blob;
39 
40 	if (*name == NULL || os_strncmp(*name, "blob://", 7) != 0)
41 		return 0;
42 
43 	blob = eap_get_config_blob(sm, *name + 7);
44 	if (blob == NULL) {
45 		wpa_printf(MSG_ERROR, "%s: Named configuration blob '%s' not "
46 			   "found", __func__, *name + 7);
47 		return -1;
48 	}
49 
50 	*name = NULL;
51 	*data = blob->data;
52 	*data_len = blob->len;
53 
54 	return 0;
55 }
56 
57 
eap_tls_params_flags(struct tls_connection_params * params,const char * txt)58 static void eap_tls_params_flags(struct tls_connection_params *params,
59 				 const char *txt)
60 {
61 	if (txt == NULL)
62 		return;
63 	if (os_strstr(txt, "tls_allow_md5=1"))
64 		params->flags |= TLS_CONN_ALLOW_SIGN_RSA_MD5;
65 	if (os_strstr(txt, "tls_disable_time_checks=1"))
66 		params->flags |= TLS_CONN_DISABLE_TIME_CHECKS;
67 	if (os_strstr(txt, "tls_disable_session_ticket=1"))
68 		params->flags |= TLS_CONN_DISABLE_SESSION_TICKET;
69 	if (os_strstr(txt, "tls_disable_session_ticket=0"))
70 		params->flags &= ~TLS_CONN_DISABLE_SESSION_TICKET;
71 	if (os_strstr(txt, "tls_disable_tlsv1_0=1"))
72 		params->flags |= TLS_CONN_DISABLE_TLSv1_0;
73 	if (os_strstr(txt, "tls_disable_tlsv1_0=0"))
74 		params->flags &= ~TLS_CONN_DISABLE_TLSv1_0;
75 	if (os_strstr(txt, "tls_disable_tlsv1_1=1"))
76 		params->flags |= TLS_CONN_DISABLE_TLSv1_1;
77 	if (os_strstr(txt, "tls_disable_tlsv1_1=0"))
78 		params->flags &= ~TLS_CONN_DISABLE_TLSv1_1;
79 	if (os_strstr(txt, "tls_disable_tlsv1_2=1"))
80 		params->flags |= TLS_CONN_DISABLE_TLSv1_2;
81 	if (os_strstr(txt, "tls_disable_tlsv1_2=0"))
82 		params->flags &= ~TLS_CONN_DISABLE_TLSv1_2;
83 	if (os_strstr(txt, "tls_ext_cert_check=1"))
84 		params->flags |= TLS_CONN_EXT_CERT_CHECK;
85 	if (os_strstr(txt, "tls_ext_cert_check=0"))
86 		params->flags &= ~TLS_CONN_EXT_CERT_CHECK;
87 }
88 
89 
eap_tls_params_from_conf1(struct tls_connection_params * params,struct eap_peer_config * config)90 static void eap_tls_params_from_conf1(struct tls_connection_params *params,
91 				      struct eap_peer_config *config)
92 {
93 	params->ca_cert = (char *) config->ca_cert;
94 	params->ca_path = (char *) config->ca_path;
95 	params->client_cert = (char *) config->client_cert;
96 	params->private_key = (char *) config->private_key;
97 	params->private_key_passwd = (char *) config->private_key_passwd;
98 	params->dh_file = (char *) config->dh_file;
99 	params->subject_match = (char *) config->subject_match;
100 	params->altsubject_match = (char *) config->altsubject_match;
101 	params->suffix_match = config->domain_suffix_match;
102 	params->domain_match = config->domain_match;
103 	params->engine = config->engine;
104 	params->engine_id = config->engine_id;
105 	params->pin = config->pin;
106 	params->key_id = config->key_id;
107 	params->cert_id = config->cert_id;
108 	params->ca_cert_id = config->ca_cert_id;
109 	eap_tls_params_flags(params, config->phase1);
110 }
111 
112 
eap_tls_params_from_conf2(struct tls_connection_params * params,struct eap_peer_config * config)113 static void eap_tls_params_from_conf2(struct tls_connection_params *params,
114 				      struct eap_peer_config *config)
115 {
116 	params->ca_cert = (char *) config->ca_cert2;
117 	params->ca_path = (char *) config->ca_path2;
118 	params->client_cert = (char *) config->client_cert2;
119 	params->private_key = (char *) config->private_key2;
120 	params->private_key_passwd = (char *) config->private_key2_passwd;
121 	params->dh_file = (char *) config->dh_file2;
122 	params->subject_match = (char *) config->subject_match2;
123 	params->altsubject_match = (char *) config->altsubject_match2;
124 	params->suffix_match = config->domain_suffix_match2;
125 	params->domain_match = config->domain_match2;
126 	params->engine = config->engine2;
127 	params->engine_id = config->engine2_id;
128 	params->pin = config->pin2;
129 	params->key_id = config->key2_id;
130 	params->cert_id = config->cert2_id;
131 	params->ca_cert_id = config->ca_cert2_id;
132 	eap_tls_params_flags(params, config->phase2);
133 }
134 
135 
eap_tls_params_from_conf(struct eap_sm * sm,struct eap_ssl_data * data,struct tls_connection_params * params,struct eap_peer_config * config,int phase2)136 static int eap_tls_params_from_conf(struct eap_sm *sm,
137 				    struct eap_ssl_data *data,
138 				    struct tls_connection_params *params,
139 				    struct eap_peer_config *config, int phase2)
140 {
141 	os_memset(params, 0, sizeof(*params));
142 	if (sm->workaround && data->eap_type != EAP_TYPE_FAST) {
143 		/*
144 		 * Some deployed authentication servers seem to be unable to
145 		 * handle the TLS Session Ticket extension (they are supposed
146 		 * to ignore unrecognized TLS extensions, but end up rejecting
147 		 * the ClientHello instead). As a workaround, disable use of
148 		 * TLS Sesson Ticket extension for EAP-TLS, EAP-PEAP, and
149 		 * EAP-TTLS (EAP-FAST uses session ticket, so any server that
150 		 * supports EAP-FAST does not need this workaround).
151 		 */
152 		params->flags |= TLS_CONN_DISABLE_SESSION_TICKET;
153 	}
154 	if (phase2) {
155 		wpa_printf(MSG_DEBUG, "TLS: using phase2 config options");
156 		eap_tls_params_from_conf2(params, config);
157 	} else {
158 		wpa_printf(MSG_DEBUG, "TLS: using phase1 config options");
159 		eap_tls_params_from_conf1(params, config);
160 		if (data->eap_type == EAP_TYPE_FAST)
161 			params->flags |= TLS_CONN_EAP_FAST;
162 	}
163 
164 	/*
165 	 * Use blob data, if available. Otherwise, leave reference to external
166 	 * file as-is.
167 	 */
168 	if (eap_tls_check_blob(sm, &params->ca_cert, &params->ca_cert_blob,
169 			       &params->ca_cert_blob_len) ||
170 	    eap_tls_check_blob(sm, &params->client_cert,
171 			       &params->client_cert_blob,
172 			       &params->client_cert_blob_len) ||
173 	    eap_tls_check_blob(sm, &params->private_key,
174 			       &params->private_key_blob,
175 			       &params->private_key_blob_len) ||
176 	    eap_tls_check_blob(sm, &params->dh_file, &params->dh_blob,
177 			       &params->dh_blob_len)) {
178 		wpa_printf(MSG_INFO, "SSL: Failed to get configuration blobs");
179 		return -1;
180 	}
181 
182 	params->openssl_ciphers = config->openssl_ciphers;
183 
184 	sm->ext_cert_check = !!(params->flags & TLS_CONN_EXT_CERT_CHECK);
185 
186 	return 0;
187 }
188 
189 
eap_tls_init_connection(struct eap_sm * sm,struct eap_ssl_data * data,struct eap_peer_config * config,struct tls_connection_params * params)190 static int eap_tls_init_connection(struct eap_sm *sm,
191 				   struct eap_ssl_data *data,
192 				   struct eap_peer_config *config,
193 				   struct tls_connection_params *params)
194 {
195 	int res;
196 
197 	if (config->ocsp)
198 		params->flags |= TLS_CONN_REQUEST_OCSP;
199 	if (config->ocsp >= 2)
200 		params->flags |= TLS_CONN_REQUIRE_OCSP;
201 	if (config->ocsp == 3)
202 		params->flags |= TLS_CONN_REQUIRE_OCSP_ALL;
203 	data->conn = tls_connection_init(data->ssl_ctx);
204 	if (data->conn == NULL) {
205 		wpa_printf(MSG_INFO, "SSL: Failed to initialize new TLS "
206 			   "connection");
207 		return -1;
208 	}
209 
210 	res = tls_connection_set_params(data->ssl_ctx, data->conn, params);
211 	if (res == TLS_SET_PARAMS_ENGINE_PRV_BAD_PIN) {
212 		/*
213 		 * At this point with the pkcs11 engine the PIN is wrong. We
214 		 * reset the PIN in the configuration to be sure to not use it
215 		 * again and the calling function must request a new one.
216 		 */
217 		wpa_printf(MSG_INFO,
218 			   "TLS: Bad PIN provided, requesting a new one");
219 		os_free(config->pin);
220 		config->pin = NULL;
221 		eap_sm_request_pin(sm);
222 		sm->ignore = TRUE;
223 	} else if (res == TLS_SET_PARAMS_ENGINE_PRV_INIT_FAILED) {
224 		wpa_printf(MSG_INFO, "TLS: Failed to initialize engine");
225 	} else if (res == TLS_SET_PARAMS_ENGINE_PRV_VERIFY_FAILED) {
226 		wpa_printf(MSG_INFO, "TLS: Failed to load private key");
227 		sm->ignore = TRUE;
228 	}
229 	if (res) {
230 		wpa_printf(MSG_INFO, "TLS: Failed to set TLS connection "
231 			   "parameters");
232 		tls_connection_deinit(data->ssl_ctx, data->conn);
233 		data->conn = NULL;
234 		return -1;
235 	}
236 
237 	return 0;
238 }
239 
240 
241 /**
242  * eap_peer_tls_ssl_init - Initialize shared TLS functionality
243  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
244  * @data: Data for TLS processing
245  * @config: Pointer to the network configuration
246  * @eap_type: EAP method used in Phase 1 (EAP_TYPE_TLS/PEAP/TTLS/FAST)
247  * Returns: 0 on success, -1 on failure
248  *
249  * This function is used to initialize shared TLS functionality for EAP-TLS,
250  * EAP-PEAP, EAP-TTLS, and EAP-FAST.
251  */
eap_peer_tls_ssl_init(struct eap_sm * sm,struct eap_ssl_data * data,struct eap_peer_config * config,u8 eap_type)252 int eap_peer_tls_ssl_init(struct eap_sm *sm, struct eap_ssl_data *data,
253 			  struct eap_peer_config *config, u8 eap_type)
254 {
255 	struct tls_connection_params params;
256 
257 	if (config == NULL)
258 		return -1;
259 
260 	data->eap = sm;
261 	data->eap_type = eap_type;
262 	data->phase2 = sm->init_phase2;
263 	data->ssl_ctx = sm->init_phase2 && sm->ssl_ctx2 ? sm->ssl_ctx2 :
264 		sm->ssl_ctx;
265 	if (eap_tls_params_from_conf(sm, data, &params, config, data->phase2) <
266 	    0)
267 		return -1;
268 
269 	if (eap_tls_init_connection(sm, data, config, &params) < 0)
270 		return -1;
271 
272 	data->tls_out_limit = config->fragment_size;
273 	if (data->phase2) {
274 		/* Limit the fragment size in the inner TLS authentication
275 		 * since the outer authentication with EAP-PEAP does not yet
276 		 * support fragmentation */
277 		if (data->tls_out_limit > 100)
278 			data->tls_out_limit -= 100;
279 	}
280 
281 	if (config->phase1 &&
282 	    os_strstr(config->phase1, "include_tls_length=1")) {
283 		wpa_printf(MSG_DEBUG, "TLS: Include TLS Message Length in "
284 			   "unfragmented packets");
285 		data->include_tls_length = 1;
286 	}
287 
288 	return 0;
289 }
290 
291 
292 /**
293  * eap_peer_tls_ssl_deinit - Deinitialize shared TLS functionality
294  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
295  * @data: Data for TLS processing
296  *
297  * This function deinitializes shared TLS functionality that was initialized
298  * with eap_peer_tls_ssl_init().
299  */
eap_peer_tls_ssl_deinit(struct eap_sm * sm,struct eap_ssl_data * data)300 void eap_peer_tls_ssl_deinit(struct eap_sm *sm, struct eap_ssl_data *data)
301 {
302 	tls_connection_deinit(data->ssl_ctx, data->conn);
303 	eap_peer_tls_reset_input(data);
304 	eap_peer_tls_reset_output(data);
305 }
306 
307 
308 /**
309  * eap_peer_tls_derive_key - Derive a key based on TLS session data
310  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
311  * @data: Data for TLS processing
312  * @label: Label string for deriving the keys, e.g., "client EAP encryption"
313  * @len: Length of the key material to generate (usually 64 for MSK)
314  * Returns: Pointer to allocated key on success or %NULL on failure
315  *
316  * This function uses TLS-PRF to generate pseudo-random data based on the TLS
317  * session data (client/server random and master key). Each key type may use a
318  * different label to bind the key usage into the generated material.
319  *
320  * The caller is responsible for freeing the returned buffer.
321  */
eap_peer_tls_derive_key(struct eap_sm * sm,struct eap_ssl_data * data,const char * label,size_t len)322 u8 * eap_peer_tls_derive_key(struct eap_sm *sm, struct eap_ssl_data *data,
323 			     const char *label, size_t len)
324 {
325 	u8 *out;
326 
327 	out = os_malloc(len);
328 	if (out == NULL)
329 		return NULL;
330 
331 	if (tls_connection_prf(data->ssl_ctx, data->conn, label, 0, 0,
332 			       out, len)) {
333 		os_free(out);
334 		return NULL;
335 	}
336 
337 	return out;
338 }
339 
340 
341 /**
342  * eap_peer_tls_derive_session_id - Derive a Session-Id based on TLS data
343  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
344  * @data: Data for TLS processing
345  * @eap_type: EAP method used in Phase 1 (EAP_TYPE_TLS/PEAP/TTLS/FAST)
346  * @len: Pointer to length of the session ID generated
347  * Returns: Pointer to allocated Session-Id on success or %NULL on failure
348  *
349  * This function derive the Session-Id based on the TLS session data
350  * (client/server random and method type).
351  *
352  * The caller is responsible for freeing the returned buffer.
353  */
eap_peer_tls_derive_session_id(struct eap_sm * sm,struct eap_ssl_data * data,u8 eap_type,size_t * len)354 u8 * eap_peer_tls_derive_session_id(struct eap_sm *sm,
355 				    struct eap_ssl_data *data, u8 eap_type,
356 				    size_t *len)
357 {
358 	struct tls_random keys;
359 	u8 *out;
360 
361 	if (tls_connection_get_random(sm->ssl_ctx, data->conn, &keys) ||
362 	    keys.client_random == NULL || keys.server_random == NULL)
363 		return NULL;
364 
365 	*len = 1 + keys.client_random_len + keys.server_random_len;
366 	out = os_malloc(*len);
367 	if (out == NULL)
368 		return NULL;
369 
370 	/* Session-Id = EAP type || client.random || server.random */
371 	out[0] = eap_type;
372 	os_memcpy(out + 1, keys.client_random, keys.client_random_len);
373 	os_memcpy(out + 1 + keys.client_random_len, keys.server_random,
374 		  keys.server_random_len);
375 
376 	return out;
377 }
378 
379 
380 /**
381  * eap_peer_tls_reassemble_fragment - Reassemble a received fragment
382  * @data: Data for TLS processing
383  * @in_data: Next incoming TLS segment
384  * Returns: 0 on success, 1 if more data is needed for the full message, or
385  * -1 on error
386  */
eap_peer_tls_reassemble_fragment(struct eap_ssl_data * data,const struct wpabuf * in_data)387 static int eap_peer_tls_reassemble_fragment(struct eap_ssl_data *data,
388 					    const struct wpabuf *in_data)
389 {
390 	size_t tls_in_len, in_len;
391 
392 	tls_in_len = data->tls_in ? wpabuf_len(data->tls_in) : 0;
393 	in_len = in_data ? wpabuf_len(in_data) : 0;
394 
395 	if (tls_in_len + in_len == 0) {
396 		/* No message data received?! */
397 		wpa_printf(MSG_WARNING, "SSL: Invalid reassembly state: "
398 			   "tls_in_left=%lu tls_in_len=%lu in_len=%lu",
399 			   (unsigned long) data->tls_in_left,
400 			   (unsigned long) tls_in_len,
401 			   (unsigned long) in_len);
402 		eap_peer_tls_reset_input(data);
403 		return -1;
404 	}
405 
406 	if (tls_in_len + in_len > 65536) {
407 		/*
408 		 * Limit length to avoid rogue servers from causing large
409 		 * memory allocations.
410 		 */
411 		wpa_printf(MSG_INFO, "SSL: Too long TLS fragment (size over "
412 			   "64 kB)");
413 		eap_peer_tls_reset_input(data);
414 		return -1;
415 	}
416 
417 	if (in_len > data->tls_in_left) {
418 		/* Sender is doing something odd - reject message */
419 		wpa_printf(MSG_INFO, "SSL: more data than TLS message length "
420 			   "indicated");
421 		eap_peer_tls_reset_input(data);
422 		return -1;
423 	}
424 
425 	if (wpabuf_resize(&data->tls_in, in_len) < 0) {
426 		wpa_printf(MSG_INFO, "SSL: Could not allocate memory for TLS "
427 			   "data");
428 		eap_peer_tls_reset_input(data);
429 		return -1;
430 	}
431 	if (in_data)
432 		wpabuf_put_buf(data->tls_in, in_data);
433 	data->tls_in_left -= in_len;
434 
435 	if (data->tls_in_left > 0) {
436 		wpa_printf(MSG_DEBUG, "SSL: Need %lu bytes more input "
437 			   "data", (unsigned long) data->tls_in_left);
438 		return 1;
439 	}
440 
441 	return 0;
442 }
443 
444 
445 /**
446  * eap_peer_tls_data_reassemble - Reassemble TLS data
447  * @data: Data for TLS processing
448  * @in_data: Next incoming TLS segment
449  * @need_more_input: Variable for returning whether more input data is needed
450  * to reassemble this TLS packet
451  * Returns: Pointer to output data, %NULL on error or when more data is needed
452  * for the full message (in which case, *need_more_input is also set to 1).
453  *
454  * This function reassembles TLS fragments. Caller must not free the returned
455  * data buffer since an internal pointer to it is maintained.
456  */
eap_peer_tls_data_reassemble(struct eap_ssl_data * data,const struct wpabuf * in_data,int * need_more_input)457 static const struct wpabuf * eap_peer_tls_data_reassemble(
458 	struct eap_ssl_data *data, const struct wpabuf *in_data,
459 	int *need_more_input)
460 {
461 	*need_more_input = 0;
462 
463 	if (data->tls_in_left > wpabuf_len(in_data) || data->tls_in) {
464 		/* Message has fragments */
465 		int res = eap_peer_tls_reassemble_fragment(data, in_data);
466 		if (res) {
467 			if (res == 1)
468 				*need_more_input = 1;
469 			return NULL;
470 		}
471 
472 		/* Message is now fully reassembled. */
473 	} else {
474 		/* No fragments in this message, so just make a copy of it. */
475 		data->tls_in_left = 0;
476 		data->tls_in = wpabuf_dup(in_data);
477 		if (data->tls_in == NULL)
478 			return NULL;
479 	}
480 
481 	return data->tls_in;
482 }
483 
484 
485 /**
486  * eap_tls_process_input - Process incoming TLS message
487  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
488  * @data: Data for TLS processing
489  * @in_data: Message received from the server
490  * @out_data: Buffer for returning a pointer to application data (if available)
491  * Returns: 0 on success, 1 if more input data is needed, 2 if application data
492  * is available, -1 on failure
493  */
eap_tls_process_input(struct eap_sm * sm,struct eap_ssl_data * data,const struct wpabuf * in_data,struct wpabuf ** out_data)494 static int eap_tls_process_input(struct eap_sm *sm, struct eap_ssl_data *data,
495 				 const struct wpabuf *in_data,
496 				 struct wpabuf **out_data)
497 {
498 	const struct wpabuf *msg;
499 	int need_more_input;
500 	struct wpabuf *appl_data;
501 
502 	msg = eap_peer_tls_data_reassemble(data, in_data, &need_more_input);
503 	if (msg == NULL)
504 		return need_more_input ? 1 : -1;
505 
506 	/* Full TLS message reassembled - continue handshake processing */
507 	if (data->tls_out) {
508 		/* This should not happen.. */
509 		wpa_printf(MSG_INFO, "SSL: eap_tls_process_input - pending "
510 			   "tls_out data even though tls_out_len = 0");
511 		wpabuf_free(data->tls_out);
512 		WPA_ASSERT(data->tls_out == NULL);
513 	}
514 	appl_data = NULL;
515 	data->tls_out = tls_connection_handshake(data->ssl_ctx, data->conn,
516 						 msg, &appl_data);
517 
518 	eap_peer_tls_reset_input(data);
519 
520 	if (appl_data &&
521 	    tls_connection_established(data->ssl_ctx, data->conn) &&
522 	    !tls_connection_get_failed(data->ssl_ctx, data->conn)) {
523 		wpa_hexdump_buf_key(MSG_MSGDUMP, "SSL: Application data",
524 				    appl_data);
525 		*out_data = appl_data;
526 		return 2;
527 	}
528 
529 	wpabuf_free(appl_data);
530 
531 	return 0;
532 }
533 
534 
535 /**
536  * eap_tls_process_output - Process outgoing TLS message
537  * @data: Data for TLS processing
538  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
539  * @peap_version: Version number for EAP-PEAP/TTLS
540  * @id: EAP identifier for the response
541  * @ret: Return value to use on success
542  * @out_data: Buffer for returning the allocated output buffer
543  * Returns: ret (0 or 1) on success, -1 on failure
544  */
eap_tls_process_output(struct eap_ssl_data * data,EapType eap_type,int peap_version,u8 id,int ret,struct wpabuf ** out_data)545 static int eap_tls_process_output(struct eap_ssl_data *data, EapType eap_type,
546 				  int peap_version, u8 id, int ret,
547 				  struct wpabuf **out_data)
548 {
549 	size_t len;
550 	u8 *flags;
551 	int more_fragments, length_included;
552 
553 	if (data->tls_out == NULL)
554 		return -1;
555 	len = wpabuf_len(data->tls_out) - data->tls_out_pos;
556 	wpa_printf(MSG_DEBUG, "SSL: %lu bytes left to be sent out (of total "
557 		   "%lu bytes)",
558 		   (unsigned long) len,
559 		   (unsigned long) wpabuf_len(data->tls_out));
560 
561 	/*
562 	 * Limit outgoing message to the configured maximum size. Fragment
563 	 * message if needed.
564 	 */
565 	if (len > data->tls_out_limit) {
566 		more_fragments = 1;
567 		len = data->tls_out_limit;
568 		wpa_printf(MSG_DEBUG, "SSL: sending %lu bytes, more fragments "
569 			   "will follow", (unsigned long) len);
570 	} else
571 		more_fragments = 0;
572 
573 	length_included = data->tls_out_pos == 0 &&
574 		(wpabuf_len(data->tls_out) > data->tls_out_limit ||
575 		 data->include_tls_length);
576 	if (!length_included &&
577 	    eap_type == EAP_TYPE_PEAP && peap_version == 0 &&
578 	    !tls_connection_established(data->eap->ssl_ctx, data->conn)) {
579 		/*
580 		 * Windows Server 2008 NPS really wants to have the TLS Message
581 		 * length included in phase 0 even for unfragmented frames or
582 		 * it will get very confused with Compound MAC calculation and
583 		 * Outer TLVs.
584 		 */
585 		length_included = 1;
586 	}
587 
588 	*out_data = eap_tls_msg_alloc(eap_type, 1 + length_included * 4 + len,
589 				      EAP_CODE_RESPONSE, id);
590 	if (*out_data == NULL)
591 		return -1;
592 
593 	flags = wpabuf_put(*out_data, 1);
594 	*flags = peap_version;
595 	if (more_fragments)
596 		*flags |= EAP_TLS_FLAGS_MORE_FRAGMENTS;
597 	if (length_included) {
598 		*flags |= EAP_TLS_FLAGS_LENGTH_INCLUDED;
599 		wpabuf_put_be32(*out_data, wpabuf_len(data->tls_out));
600 	}
601 
602 	wpabuf_put_data(*out_data,
603 			wpabuf_head_u8(data->tls_out) + data->tls_out_pos,
604 			len);
605 	data->tls_out_pos += len;
606 
607 	if (!more_fragments)
608 		eap_peer_tls_reset_output(data);
609 
610 	return ret;
611 }
612 
613 
614 /**
615  * eap_peer_tls_process_helper - Process TLS handshake message
616  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
617  * @data: Data for TLS processing
618  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
619  * @peap_version: Version number for EAP-PEAP/TTLS
620  * @id: EAP identifier for the response
621  * @in_data: Message received from the server
622  * @out_data: Buffer for returning a pointer to the response message
623  * Returns: 0 on success, 1 if more input data is needed, 2 if application data
624  * is available, or -1 on failure
625  *
626  * This function can be used to process TLS handshake messages. It reassembles
627  * the received fragments and uses a TLS library to process the messages. The
628  * response data from the TLS library is fragmented to suitable output messages
629  * that the caller can send out.
630  *
631  * out_data is used to return the response message if the return value of this
632  * function is 0, 2, or -1. In case of failure, the message is likely a TLS
633  * alarm message. The caller is responsible for freeing the allocated buffer if
634  * *out_data is not %NULL.
635  *
636  * This function is called for each received TLS message during the TLS
637  * handshake after eap_peer_tls_process_init() call and possible processing of
638  * TLS Flags field. Once the handshake has been completed, i.e., when
639  * tls_connection_established() returns 1, EAP method specific decrypting of
640  * the tunneled data is used.
641  */
eap_peer_tls_process_helper(struct eap_sm * sm,struct eap_ssl_data * data,EapType eap_type,int peap_version,u8 id,const struct wpabuf * in_data,struct wpabuf ** out_data)642 int eap_peer_tls_process_helper(struct eap_sm *sm, struct eap_ssl_data *data,
643 				EapType eap_type, int peap_version,
644 				u8 id, const struct wpabuf *in_data,
645 				struct wpabuf **out_data)
646 {
647 	int ret = 0;
648 
649 	*out_data = NULL;
650 
651 	if (data->tls_out && wpabuf_len(data->tls_out) > 0 &&
652 	    wpabuf_len(in_data) > 0) {
653 		wpa_printf(MSG_DEBUG, "SSL: Received non-ACK when output "
654 			   "fragments are waiting to be sent out");
655 		return -1;
656 	}
657 
658 	if (data->tls_out == NULL || wpabuf_len(data->tls_out) == 0) {
659 		/*
660 		 * No more data to send out - expect to receive more data from
661 		 * the AS.
662 		 */
663 		int res = eap_tls_process_input(sm, data, in_data, out_data);
664 		if (res) {
665 			/*
666 			 * Input processing failed (res = -1) or more data is
667 			 * needed (res = 1).
668 			 */
669 			return res;
670 		}
671 
672 		/*
673 		 * The incoming message has been reassembled and processed. The
674 		 * response was allocated into data->tls_out buffer.
675 		 */
676 	}
677 
678 	if (data->tls_out == NULL) {
679 		/*
680 		 * No outgoing fragments remaining from the previous message
681 		 * and no new message generated. This indicates an error in TLS
682 		 * processing.
683 		 */
684 		eap_peer_tls_reset_output(data);
685 		return -1;
686 	}
687 
688 	if (tls_connection_get_failed(data->ssl_ctx, data->conn)) {
689 		/* TLS processing has failed - return error */
690 		wpa_printf(MSG_DEBUG, "SSL: Failed - tls_out available to "
691 			   "report error (len=%u)",
692 			   (unsigned int) wpabuf_len(data->tls_out));
693 		ret = -1;
694 		/* TODO: clean pin if engine used? */
695 		if (wpabuf_len(data->tls_out) == 0) {
696 			wpabuf_free(data->tls_out);
697 			data->tls_out = NULL;
698 			return -1;
699 		}
700 	}
701 
702 	if (wpabuf_len(data->tls_out) == 0) {
703 		/*
704 		 * TLS negotiation should now be complete since all other cases
705 		 * needing more data should have been caught above based on
706 		 * the TLS Message Length field.
707 		 */
708 		wpa_printf(MSG_DEBUG, "SSL: No data to be sent out");
709 		wpabuf_free(data->tls_out);
710 		data->tls_out = NULL;
711 		return 1;
712 	}
713 
714 	/* Send the pending message (in fragments, if needed). */
715 	return eap_tls_process_output(data, eap_type, peap_version, id, ret,
716 				      out_data);
717 }
718 
719 
720 /**
721  * eap_peer_tls_build_ack - Build a TLS ACK frame
722  * @id: EAP identifier for the response
723  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
724  * @peap_version: Version number for EAP-PEAP/TTLS
725  * Returns: Pointer to the allocated ACK frame or %NULL on failure
726  */
eap_peer_tls_build_ack(u8 id,EapType eap_type,int peap_version)727 struct wpabuf * eap_peer_tls_build_ack(u8 id, EapType eap_type,
728 				       int peap_version)
729 {
730 	struct wpabuf *resp;
731 
732 	resp = eap_tls_msg_alloc(eap_type, 1, EAP_CODE_RESPONSE, id);
733 	if (resp == NULL)
734 		return NULL;
735 	wpa_printf(MSG_DEBUG, "SSL: Building ACK (type=%d id=%d ver=%d)",
736 		   (int) eap_type, id, peap_version);
737 	wpabuf_put_u8(resp, peap_version); /* Flags */
738 	return resp;
739 }
740 
741 
742 /**
743  * eap_peer_tls_reauth_init - Re-initialize shared TLS for session resumption
744  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
745  * @data: Data for TLS processing
746  * Returns: 0 on success, -1 on failure
747  */
eap_peer_tls_reauth_init(struct eap_sm * sm,struct eap_ssl_data * data)748 int eap_peer_tls_reauth_init(struct eap_sm *sm, struct eap_ssl_data *data)
749 {
750 	eap_peer_tls_reset_input(data);
751 	eap_peer_tls_reset_output(data);
752 	return tls_connection_shutdown(data->ssl_ctx, data->conn);
753 }
754 
755 
756 /**
757  * eap_peer_tls_status - Get TLS status
758  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
759  * @data: Data for TLS processing
760  * @buf: Buffer for status information
761  * @buflen: Maximum buffer length
762  * @verbose: Whether to include verbose status information
763  * Returns: Number of bytes written to buf.
764  */
eap_peer_tls_status(struct eap_sm * sm,struct eap_ssl_data * data,char * buf,size_t buflen,int verbose)765 int eap_peer_tls_status(struct eap_sm *sm, struct eap_ssl_data *data,
766 			char *buf, size_t buflen, int verbose)
767 {
768 	char version[20], name[128];
769 	int len = 0, ret;
770 
771 	if (tls_get_version(data->ssl_ctx, data->conn, version,
772 			    sizeof(version)) < 0)
773 		version[0] = '\0';
774 	if (tls_get_cipher(data->ssl_ctx, data->conn, name, sizeof(name)) < 0)
775 		name[0] = '\0';
776 
777 	ret = os_snprintf(buf + len, buflen - len,
778 			  "eap_tls_version=%s\n"
779 			  "EAP TLS cipher=%s\n"
780 			  "tls_session_reused=%d\n",
781 			  version, name,
782 			  tls_connection_resumed(data->ssl_ctx, data->conn));
783 	if (os_snprintf_error(buflen - len, ret))
784 		return len;
785 	len += ret;
786 
787 	return len;
788 }
789 
790 
791 /**
792  * eap_peer_tls_process_init - Initial validation/processing of EAP requests
793  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
794  * @data: Data for TLS processing
795  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
796  * @ret: Return values from EAP request validation and processing
797  * @reqData: EAP request to be processed (eapReqData)
798  * @len: Buffer for returning length of the remaining payload
799  * @flags: Buffer for returning TLS flags
800  * Returns: Pointer to payload after TLS flags and length or %NULL on failure
801  *
802  * This function validates the EAP header and processes the optional TLS
803  * Message Length field. If this is the first fragment of a TLS message, the
804  * TLS reassembly code is initialized to receive the indicated number of bytes.
805  *
806  * EAP-TLS, EAP-PEAP, EAP-TTLS, and EAP-FAST methods are expected to use this
807  * function as the first step in processing received messages. They will need
808  * to process the flags (apart from Message Length Included) that are returned
809  * through the flags pointer and the message payload that will be returned (and
810  * the length is returned through the len pointer). Return values (ret) are set
811  * for continuation of EAP method processing. The caller is responsible for
812  * setting these to indicate completion (either success or failure) based on
813  * the authentication result.
814  */
eap_peer_tls_process_init(struct eap_sm * sm,struct eap_ssl_data * data,EapType eap_type,struct eap_method_ret * ret,const struct wpabuf * reqData,size_t * len,u8 * flags)815 const u8 * eap_peer_tls_process_init(struct eap_sm *sm,
816 				     struct eap_ssl_data *data,
817 				     EapType eap_type,
818 				     struct eap_method_ret *ret,
819 				     const struct wpabuf *reqData,
820 				     size_t *len, u8 *flags)
821 {
822 	const u8 *pos;
823 	size_t left;
824 	unsigned int tls_msg_len;
825 
826 	if (tls_get_errors(data->ssl_ctx)) {
827 		wpa_printf(MSG_INFO, "SSL: TLS errors detected");
828 		ret->ignore = TRUE;
829 		return NULL;
830 	}
831 
832 	if (eap_type == EAP_UNAUTH_TLS_TYPE)
833 		pos = eap_hdr_validate(EAP_VENDOR_UNAUTH_TLS,
834 				       EAP_VENDOR_TYPE_UNAUTH_TLS, reqData,
835 				       &left);
836 	else if (eap_type == EAP_WFA_UNAUTH_TLS_TYPE)
837 		pos = eap_hdr_validate(EAP_VENDOR_WFA_NEW,
838 				       EAP_VENDOR_WFA_UNAUTH_TLS, reqData,
839 				       &left);
840 	else
841 		pos = eap_hdr_validate(EAP_VENDOR_IETF, eap_type, reqData,
842 				       &left);
843 	if (pos == NULL) {
844 		ret->ignore = TRUE;
845 		return NULL;
846 	}
847 	if (left == 0) {
848 		wpa_printf(MSG_DEBUG, "SSL: Invalid TLS message: no Flags "
849 			   "octet included");
850 		if (!sm->workaround) {
851 			ret->ignore = TRUE;
852 			return NULL;
853 		}
854 
855 		wpa_printf(MSG_DEBUG, "SSL: Workaround - assume no Flags "
856 			   "indicates ACK frame");
857 		*flags = 0;
858 	} else {
859 		*flags = *pos++;
860 		left--;
861 	}
862 	wpa_printf(MSG_DEBUG, "SSL: Received packet(len=%lu) - "
863 		   "Flags 0x%02x", (unsigned long) wpabuf_len(reqData),
864 		   *flags);
865 	if (*flags & EAP_TLS_FLAGS_LENGTH_INCLUDED) {
866 		if (left < 4) {
867 			wpa_printf(MSG_INFO, "SSL: Short frame with TLS "
868 				   "length");
869 			ret->ignore = TRUE;
870 			return NULL;
871 		}
872 		tls_msg_len = WPA_GET_BE32(pos);
873 		wpa_printf(MSG_DEBUG, "SSL: TLS Message Length: %d",
874 			   tls_msg_len);
875 		if (data->tls_in_left == 0) {
876 			data->tls_in_total = tls_msg_len;
877 			data->tls_in_left = tls_msg_len;
878 			wpabuf_free(data->tls_in);
879 			data->tls_in = NULL;
880 		}
881 		pos += 4;
882 		left -= 4;
883 
884 		if (left > tls_msg_len) {
885 			wpa_printf(MSG_INFO, "SSL: TLS Message Length (%d "
886 				   "bytes) smaller than this fragment (%d "
887 				   "bytes)", (int) tls_msg_len, (int) left);
888 			ret->ignore = TRUE;
889 			return NULL;
890 		}
891 	}
892 
893 	ret->ignore = FALSE;
894 	ret->methodState = METHOD_MAY_CONT;
895 	ret->decision = DECISION_FAIL;
896 	ret->allowNotifications = TRUE;
897 
898 	*len = left;
899 	return pos;
900 }
901 
902 
903 /**
904  * eap_peer_tls_reset_input - Reset input buffers
905  * @data: Data for TLS processing
906  *
907  * This function frees any allocated memory for input buffers and resets input
908  * state.
909  */
eap_peer_tls_reset_input(struct eap_ssl_data * data)910 void eap_peer_tls_reset_input(struct eap_ssl_data *data)
911 {
912 	data->tls_in_left = data->tls_in_total = 0;
913 	wpabuf_free(data->tls_in);
914 	data->tls_in = NULL;
915 }
916 
917 
918 /**
919  * eap_peer_tls_reset_output - Reset output buffers
920  * @data: Data for TLS processing
921  *
922  * This function frees any allocated memory for output buffers and resets
923  * output state.
924  */
eap_peer_tls_reset_output(struct eap_ssl_data * data)925 void eap_peer_tls_reset_output(struct eap_ssl_data *data)
926 {
927 	data->tls_out_pos = 0;
928 	wpabuf_free(data->tls_out);
929 	data->tls_out = NULL;
930 }
931 
932 
933 /**
934  * eap_peer_tls_decrypt - Decrypt received phase 2 TLS message
935  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
936  * @data: Data for TLS processing
937  * @in_data: Message received from the server
938  * @in_decrypted: Buffer for returning a pointer to the decrypted message
939  * Returns: 0 on success, 1 if more input data is needed, or -1 on failure
940  */
eap_peer_tls_decrypt(struct eap_sm * sm,struct eap_ssl_data * data,const struct wpabuf * in_data,struct wpabuf ** in_decrypted)941 int eap_peer_tls_decrypt(struct eap_sm *sm, struct eap_ssl_data *data,
942 			 const struct wpabuf *in_data,
943 			 struct wpabuf **in_decrypted)
944 {
945 	const struct wpabuf *msg;
946 	int need_more_input;
947 
948 	msg = eap_peer_tls_data_reassemble(data, in_data, &need_more_input);
949 	if (msg == NULL)
950 		return need_more_input ? 1 : -1;
951 
952 	*in_decrypted = tls_connection_decrypt(data->ssl_ctx, data->conn, msg);
953 	eap_peer_tls_reset_input(data);
954 	if (*in_decrypted == NULL) {
955 		wpa_printf(MSG_INFO, "SSL: Failed to decrypt Phase 2 data");
956 		return -1;
957 	}
958 	return 0;
959 }
960 
961 
962 /**
963  * eap_peer_tls_encrypt - Encrypt phase 2 TLS message
964  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
965  * @data: Data for TLS processing
966  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
967  * @peap_version: Version number for EAP-PEAP/TTLS
968  * @id: EAP identifier for the response
969  * @in_data: Plaintext phase 2 data to encrypt or %NULL to continue fragments
970  * @out_data: Buffer for returning a pointer to the encrypted response message
971  * Returns: 0 on success, -1 on failure
972  */
eap_peer_tls_encrypt(struct eap_sm * sm,struct eap_ssl_data * data,EapType eap_type,int peap_version,u8 id,const struct wpabuf * in_data,struct wpabuf ** out_data)973 int eap_peer_tls_encrypt(struct eap_sm *sm, struct eap_ssl_data *data,
974 			 EapType eap_type, int peap_version, u8 id,
975 			 const struct wpabuf *in_data,
976 			 struct wpabuf **out_data)
977 {
978 	if (in_data) {
979 		eap_peer_tls_reset_output(data);
980 		data->tls_out = tls_connection_encrypt(data->ssl_ctx,
981 						       data->conn, in_data);
982 		if (data->tls_out == NULL) {
983 			wpa_printf(MSG_INFO, "SSL: Failed to encrypt Phase 2 "
984 				   "data (in_len=%lu)",
985 				   (unsigned long) wpabuf_len(in_data));
986 			eap_peer_tls_reset_output(data);
987 			return -1;
988 		}
989 	}
990 
991 	return eap_tls_process_output(data, eap_type, peap_version, id, 0,
992 				      out_data);
993 }
994 
995 
996 /**
997  * eap_peer_select_phase2_methods - Select phase 2 EAP method
998  * @config: Pointer to the network configuration
999  * @prefix: 'phase2' configuration prefix, e.g., "auth="
1000  * @types: Buffer for returning allocated list of allowed EAP methods
1001  * @num_types: Buffer for returning number of allocated EAP methods
1002  * Returns: 0 on success, -1 on failure
1003  *
1004  * This function is used to parse EAP method list and select allowed methods
1005  * for Phase2 authentication.
1006  */
eap_peer_select_phase2_methods(struct eap_peer_config * config,const char * prefix,struct eap_method_type ** types,size_t * num_types)1007 int eap_peer_select_phase2_methods(struct eap_peer_config *config,
1008 				   const char *prefix,
1009 				   struct eap_method_type **types,
1010 				   size_t *num_types)
1011 {
1012 	char *start, *pos, *buf;
1013 	struct eap_method_type *methods = NULL, *_methods;
1014 	u32 method;
1015 	size_t num_methods = 0, prefix_len;
1016 
1017 	if (config == NULL || config->phase2 == NULL)
1018 		goto get_defaults;
1019 
1020 	start = buf = os_strdup(config->phase2);
1021 	if (buf == NULL)
1022 		return -1;
1023 
1024 	prefix_len = os_strlen(prefix);
1025 
1026 	while (start && *start != '\0') {
1027 		int vendor;
1028 		pos = os_strstr(start, prefix);
1029 		if (pos == NULL)
1030 			break;
1031 		if (start != pos && *(pos - 1) != ' ') {
1032 			start = pos + prefix_len;
1033 			continue;
1034 		}
1035 
1036 		start = pos + prefix_len;
1037 		pos = os_strchr(start, ' ');
1038 		if (pos)
1039 			*pos++ = '\0';
1040 		method = eap_get_phase2_type(start, &vendor);
1041 		if (vendor == EAP_VENDOR_IETF && method == EAP_TYPE_NONE) {
1042 			wpa_printf(MSG_ERROR, "TLS: Unsupported Phase2 EAP "
1043 				   "method '%s'", start);
1044 			os_free(methods);
1045 			os_free(buf);
1046 			return -1;
1047 		} else {
1048 			num_methods++;
1049 			_methods = os_realloc_array(methods, num_methods,
1050 						    sizeof(*methods));
1051 			if (_methods == NULL) {
1052 				os_free(methods);
1053 				os_free(buf);
1054 				return -1;
1055 			}
1056 			methods = _methods;
1057 			methods[num_methods - 1].vendor = vendor;
1058 			methods[num_methods - 1].method = method;
1059 		}
1060 
1061 		start = pos;
1062 	}
1063 
1064 	os_free(buf);
1065 
1066 get_defaults:
1067 	if (methods == NULL)
1068 		methods = eap_get_phase2_types(config, &num_methods);
1069 
1070 	if (methods == NULL) {
1071 		wpa_printf(MSG_ERROR, "TLS: No Phase2 EAP methods available");
1072 		return -1;
1073 	}
1074 	wpa_hexdump(MSG_DEBUG, "TLS: Phase2 EAP types",
1075 		    (u8 *) methods,
1076 		    num_methods * sizeof(struct eap_method_type));
1077 
1078 	*types = methods;
1079 	*num_types = num_methods;
1080 
1081 	return 0;
1082 }
1083 
1084 
1085 /**
1086  * eap_peer_tls_phase2_nak - Generate EAP-Nak for Phase 2
1087  * @types: Buffer for returning allocated list of allowed EAP methods
1088  * @num_types: Buffer for returning number of allocated EAP methods
1089  * @hdr: EAP-Request header (and the following EAP type octet)
1090  * @resp: Buffer for returning the EAP-Nak message
1091  * Returns: 0 on success, -1 on failure
1092  */
eap_peer_tls_phase2_nak(struct eap_method_type * types,size_t num_types,struct eap_hdr * hdr,struct wpabuf ** resp)1093 int eap_peer_tls_phase2_nak(struct eap_method_type *types, size_t num_types,
1094 			    struct eap_hdr *hdr, struct wpabuf **resp)
1095 {
1096 	u8 *pos = (u8 *) (hdr + 1);
1097 	size_t i;
1098 
1099 	/* TODO: add support for expanded Nak */
1100 	wpa_printf(MSG_DEBUG, "TLS: Phase 2 Request: Nak type=%d", *pos);
1101 	wpa_hexdump(MSG_DEBUG, "TLS: Allowed Phase2 EAP types",
1102 		    (u8 *) types, num_types * sizeof(struct eap_method_type));
1103 	*resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_NAK, num_types,
1104 			      EAP_CODE_RESPONSE, hdr->identifier);
1105 	if (*resp == NULL)
1106 		return -1;
1107 
1108 	for (i = 0; i < num_types; i++) {
1109 		if (types[i].vendor == EAP_VENDOR_IETF &&
1110 		    types[i].method < 256)
1111 			wpabuf_put_u8(*resp, types[i].method);
1112 	}
1113 
1114 	eap_update_len(*resp);
1115 
1116 	return 0;
1117 }
1118