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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 	return eap_msg_alloc(EAP_VENDOR_IETF, type, payload_len, code,
27 			     identifier);
28 }
29 
30 
eap_tls_check_blob(struct eap_sm * sm,const char ** name,const u8 ** data,size_t * data_len)31 static int eap_tls_check_blob(struct eap_sm *sm, const char **name,
32 			      const u8 **data, size_t *data_len)
33 {
34 	const struct wpa_config_blob *blob;
35 
36 	if (*name == NULL || os_strncmp(*name, "blob://", 7) != 0)
37 		return 0;
38 
39 	blob = eap_get_config_blob(sm, *name + 7);
40 	if (blob == NULL) {
41 		wpa_printf(MSG_ERROR, "%s: Named configuration blob '%s' not "
42 			   "found", __func__, *name + 7);
43 		return -1;
44 	}
45 
46 	*name = NULL;
47 	*data = blob->data;
48 	*data_len = blob->len;
49 
50 	return 0;
51 }
52 
53 
eap_tls_params_flags(struct tls_connection_params * params,const char * txt)54 static void eap_tls_params_flags(struct tls_connection_params *params,
55 				 const char *txt)
56 {
57 	if (txt == NULL)
58 		return;
59 	if (os_strstr(txt, "tls_allow_md5=1"))
60 		params->flags |= TLS_CONN_ALLOW_SIGN_RSA_MD5;
61 	if (os_strstr(txt, "tls_disable_time_checks=1"))
62 		params->flags |= TLS_CONN_DISABLE_TIME_CHECKS;
63 	if (os_strstr(txt, "tls_disable_session_ticket=1"))
64 		params->flags |= TLS_CONN_DISABLE_SESSION_TICKET;
65 	if (os_strstr(txt, "tls_disable_session_ticket=0"))
66 		params->flags &= ~TLS_CONN_DISABLE_SESSION_TICKET;
67 }
68 
69 
eap_tls_params_from_conf1(struct tls_connection_params * params,struct eap_peer_config * config)70 static void eap_tls_params_from_conf1(struct tls_connection_params *params,
71 				      struct eap_peer_config *config)
72 {
73 	params->ca_cert = (char *) config->ca_cert;
74 	params->ca_path = (char *) config->ca_path;
75 	params->client_cert = (char *) config->client_cert;
76 	params->private_key = (char *) config->private_key;
77 	params->private_key_passwd = (char *) config->private_key_passwd;
78 	params->dh_file = (char *) config->dh_file;
79 	params->subject_match = (char *) config->subject_match;
80 	params->altsubject_match = (char *) config->altsubject_match;
81 	params->engine = config->engine;
82 	params->engine_id = config->engine_id;
83 	params->pin = config->pin;
84 	params->key_id = config->key_id;
85 	params->cert_id = config->cert_id;
86 	params->ca_cert_id = config->ca_cert_id;
87 	eap_tls_params_flags(params, config->phase1);
88 }
89 
90 
eap_tls_params_from_conf2(struct tls_connection_params * params,struct eap_peer_config * config)91 static void eap_tls_params_from_conf2(struct tls_connection_params *params,
92 				      struct eap_peer_config *config)
93 {
94 	params->ca_cert = (char *) config->ca_cert2;
95 	params->ca_path = (char *) config->ca_path2;
96 	params->client_cert = (char *) config->client_cert2;
97 	params->private_key = (char *) config->private_key2;
98 	params->private_key_passwd = (char *) config->private_key2_passwd;
99 	params->dh_file = (char *) config->dh_file2;
100 	params->subject_match = (char *) config->subject_match2;
101 	params->altsubject_match = (char *) config->altsubject_match2;
102 	params->engine = config->engine2;
103 	params->engine_id = config->engine2_id;
104 	params->pin = config->pin2;
105 	params->key_id = config->key2_id;
106 	params->cert_id = config->cert2_id;
107 	params->ca_cert_id = config->ca_cert2_id;
108 	eap_tls_params_flags(params, config->phase2);
109 }
110 
111 
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)112 static int eap_tls_params_from_conf(struct eap_sm *sm,
113 				    struct eap_ssl_data *data,
114 				    struct tls_connection_params *params,
115 				    struct eap_peer_config *config, int phase2)
116 {
117 	os_memset(params, 0, sizeof(*params));
118 	if (sm->workaround && data->eap_type != EAP_TYPE_FAST) {
119 		/*
120 		 * Some deployed authentication servers seem to be unable to
121 		 * handle the TLS Session Ticket extension (they are supposed
122 		 * to ignore unrecognized TLS extensions, but end up rejecting
123 		 * the ClientHello instead). As a workaround, disable use of
124 		 * TLS Sesson Ticket extension for EAP-TLS, EAP-PEAP, and
125 		 * EAP-TTLS (EAP-FAST uses session ticket, so any server that
126 		 * supports EAP-FAST does not need this workaround).
127 		 */
128 		params->flags |= TLS_CONN_DISABLE_SESSION_TICKET;
129 	}
130 	if (phase2) {
131 		wpa_printf(MSG_DEBUG, "TLS: using phase2 config options");
132 		eap_tls_params_from_conf2(params, config);
133 	} else {
134 		wpa_printf(MSG_DEBUG, "TLS: using phase1 config options");
135 		eap_tls_params_from_conf1(params, config);
136 	}
137 
138 	/*
139 	 * Use blob data, if available. Otherwise, leave reference to external
140 	 * file as-is.
141 	 */
142 	if (eap_tls_check_blob(sm, &params->ca_cert, &params->ca_cert_blob,
143 			       &params->ca_cert_blob_len) ||
144 	    eap_tls_check_blob(sm, &params->client_cert,
145 			       &params->client_cert_blob,
146 			       &params->client_cert_blob_len) ||
147 	    eap_tls_check_blob(sm, &params->private_key,
148 			       &params->private_key_blob,
149 			       &params->private_key_blob_len) ||
150 	    eap_tls_check_blob(sm, &params->dh_file, &params->dh_blob,
151 			       &params->dh_blob_len)) {
152 		wpa_printf(MSG_INFO, "SSL: Failed to get configuration blobs");
153 		return -1;
154 	}
155 
156 	return 0;
157 }
158 
159 
eap_tls_init_connection(struct eap_sm * sm,struct eap_ssl_data * data,struct eap_peer_config * config,struct tls_connection_params * params)160 static int eap_tls_init_connection(struct eap_sm *sm,
161 				   struct eap_ssl_data *data,
162 				   struct eap_peer_config *config,
163 				   struct tls_connection_params *params)
164 {
165 	int res;
166 
167 	if (config->ocsp)
168 		params->flags |= TLS_CONN_REQUEST_OCSP;
169 	if (config->ocsp == 2)
170 		params->flags |= TLS_CONN_REQUIRE_OCSP;
171 	data->conn = tls_connection_init(data->ssl_ctx);
172 	if (data->conn == NULL) {
173 		wpa_printf(MSG_INFO, "SSL: Failed to initialize new TLS "
174 			   "connection");
175 		return -1;
176 	}
177 
178 	res = tls_connection_set_params(data->ssl_ctx, data->conn, params);
179 	if (res == TLS_SET_PARAMS_ENGINE_PRV_INIT_FAILED) {
180 		/*
181 		 * At this point with the pkcs11 engine the PIN might be wrong.
182 		 * We reset the PIN in the configuration to be sure to not use
183 		 * it again and the calling function must request a new one.
184 		 */
185 		os_free(config->pin);
186 		config->pin = NULL;
187 	} else if (res == TLS_SET_PARAMS_ENGINE_PRV_VERIFY_FAILED) {
188 		wpa_printf(MSG_INFO, "TLS: Failed to load private key");
189 		/*
190 		 * We do not know exactly but maybe the PIN was wrong,
191 		 * so ask for a new one.
192 		 */
193 		os_free(config->pin);
194 		config->pin = NULL;
195 		eap_sm_request_pin(sm);
196 		sm->ignore = TRUE;
197 		tls_connection_deinit(data->ssl_ctx, data->conn);
198 		data->conn = NULL;
199 		return -1;
200 	} else if (res) {
201 		wpa_printf(MSG_INFO, "TLS: Failed to set TLS connection "
202 			   "parameters");
203 		tls_connection_deinit(data->ssl_ctx, data->conn);
204 		data->conn = NULL;
205 		return -1;
206 	}
207 
208 	return 0;
209 }
210 
211 
212 /**
213  * eap_peer_tls_ssl_init - Initialize shared TLS functionality
214  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
215  * @data: Data for TLS processing
216  * @config: Pointer to the network configuration
217  * @eap_type: EAP method used in Phase 1 (EAP_TYPE_TLS/PEAP/TTLS/FAST)
218  * Returns: 0 on success, -1 on failure
219  *
220  * This function is used to initialize shared TLS functionality for EAP-TLS,
221  * EAP-PEAP, EAP-TTLS, and EAP-FAST.
222  */
eap_peer_tls_ssl_init(struct eap_sm * sm,struct eap_ssl_data * data,struct eap_peer_config * config,u8 eap_type)223 int eap_peer_tls_ssl_init(struct eap_sm *sm, struct eap_ssl_data *data,
224 			  struct eap_peer_config *config, u8 eap_type)
225 {
226 	struct tls_connection_params params;
227 
228 	if (config == NULL)
229 		return -1;
230 
231 	data->eap = sm;
232 	data->eap_type = eap_type;
233 	data->phase2 = sm->init_phase2;
234 	data->ssl_ctx = sm->init_phase2 && sm->ssl_ctx2 ? sm->ssl_ctx2 :
235 		sm->ssl_ctx;
236 	if (eap_tls_params_from_conf(sm, data, &params, config, data->phase2) <
237 	    0)
238 		return -1;
239 
240 	if (eap_tls_init_connection(sm, data, config, &params) < 0)
241 		return -1;
242 
243 	data->tls_out_limit = config->fragment_size;
244 	if (data->phase2) {
245 		/* Limit the fragment size in the inner TLS authentication
246 		 * since the outer authentication with EAP-PEAP does not yet
247 		 * support fragmentation */
248 		if (data->tls_out_limit > 100)
249 			data->tls_out_limit -= 100;
250 	}
251 
252 	if (config->phase1 &&
253 	    os_strstr(config->phase1, "include_tls_length=1")) {
254 		wpa_printf(MSG_DEBUG, "TLS: Include TLS Message Length in "
255 			   "unfragmented packets");
256 		data->include_tls_length = 1;
257 	}
258 
259 	return 0;
260 }
261 
262 
263 /**
264  * eap_peer_tls_ssl_deinit - Deinitialize shared TLS functionality
265  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
266  * @data: Data for TLS processing
267  *
268  * This function deinitializes shared TLS functionality that was initialized
269  * with eap_peer_tls_ssl_init().
270  */
eap_peer_tls_ssl_deinit(struct eap_sm * sm,struct eap_ssl_data * data)271 void eap_peer_tls_ssl_deinit(struct eap_sm *sm, struct eap_ssl_data *data)
272 {
273 	tls_connection_deinit(data->ssl_ctx, data->conn);
274 	eap_peer_tls_reset_input(data);
275 	eap_peer_tls_reset_output(data);
276 }
277 
278 
279 /**
280  * eap_peer_tls_derive_key - Derive a key based on TLS session data
281  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
282  * @data: Data for TLS processing
283  * @label: Label string for deriving the keys, e.g., "client EAP encryption"
284  * @len: Length of the key material to generate (usually 64 for MSK)
285  * Returns: Pointer to allocated key on success or %NULL on failure
286  *
287  * This function uses TLS-PRF to generate pseudo-random data based on the TLS
288  * session data (client/server random and master key). Each key type may use a
289  * different label to bind the key usage into the generated material.
290  *
291  * The caller is responsible for freeing the returned buffer.
292  */
eap_peer_tls_derive_key(struct eap_sm * sm,struct eap_ssl_data * data,const char * label,size_t len)293 u8 * eap_peer_tls_derive_key(struct eap_sm *sm, struct eap_ssl_data *data,
294 			     const char *label, size_t len)
295 {
296 #ifndef CONFIG_FIPS
297 	struct tls_keys keys;
298 #endif /* CONFIG_FIPS */
299 	u8 *rnd = NULL, *out;
300 
301 	out = os_malloc(len);
302 	if (out == NULL)
303 		return NULL;
304 
305 	/* First, try to use TLS library function for PRF, if available. */
306 	if (tls_connection_prf(data->ssl_ctx, data->conn, label, 0, out, len)
307 	    == 0)
308 		return out;
309 
310 #ifndef CONFIG_FIPS
311 	/*
312 	 * TLS library did not support key generation, so get the needed TLS
313 	 * session parameters and use an internal implementation of TLS PRF to
314 	 * derive the key.
315 	 */
316 	if (tls_connection_get_keys(data->ssl_ctx, data->conn, &keys))
317 		goto fail;
318 
319 	if (keys.client_random == NULL || keys.server_random == NULL ||
320 	    keys.master_key == NULL)
321 		goto fail;
322 
323 	rnd = os_malloc(keys.client_random_len + keys.server_random_len);
324 	if (rnd == NULL)
325 		goto fail;
326 	os_memcpy(rnd, keys.client_random, keys.client_random_len);
327 	os_memcpy(rnd + keys.client_random_len, keys.server_random,
328 		  keys.server_random_len);
329 
330 	if (tls_prf_sha1_md5(keys.master_key, keys.master_key_len,
331 			     label, rnd, keys.client_random_len +
332 			     keys.server_random_len, out, len))
333 		goto fail;
334 
335 	os_free(rnd);
336 	return out;
337 
338 fail:
339 #endif /* CONFIG_FIPS */
340 	os_free(out);
341 	os_free(rnd);
342 	return NULL;
343 }
344 
345 
346 /**
347  * eap_peer_tls_derive_session_id - Derive a Session-Id based on TLS data
348  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
349  * @data: Data for TLS processing
350  * @eap_type: EAP method used in Phase 1 (EAP_TYPE_TLS/PEAP/TTLS/FAST)
351  * @len: Pointer to length of the session ID generated
352  * Returns: Pointer to allocated Session-Id on success or %NULL on failure
353  *
354  * This function derive the Session-Id based on the TLS session data
355  * (client/server random and method type).
356  *
357  * The caller is responsible for freeing the returned buffer.
358  */
eap_peer_tls_derive_session_id(struct eap_sm * sm,struct eap_ssl_data * data,u8 eap_type,size_t * len)359 u8 * eap_peer_tls_derive_session_id(struct eap_sm *sm,
360 				    struct eap_ssl_data *data, u8 eap_type,
361 				    size_t *len)
362 {
363 	struct tls_keys keys;
364 	u8 *out;
365 
366 	/*
367 	 * TLS library did not support session ID generation,
368 	 * so get the needed TLS session parameters
369 	 */
370 	if (tls_connection_get_keys(sm->ssl_ctx, data->conn, &keys))
371 		return NULL;
372 
373 	if (keys.client_random == NULL || keys.server_random == NULL ||
374 	    keys.master_key == NULL)
375 		return NULL;
376 
377 	*len = 1 + keys.client_random_len + keys.server_random_len;
378 	out = os_malloc(*len);
379 	if (out == NULL)
380 		return NULL;
381 
382 	/* Session-Id = EAP type || client.random || server.random */
383 	out[0] = eap_type;
384 	os_memcpy(out + 1, keys.client_random, keys.client_random_len);
385 	os_memcpy(out + 1 + keys.client_random_len, keys.server_random,
386 	          keys.server_random_len);
387 
388 	return out;
389 }
390 
391 
392 /**
393  * eap_peer_tls_reassemble_fragment - Reassemble a received fragment
394  * @data: Data for TLS processing
395  * @in_data: Next incoming TLS segment
396  * Returns: 0 on success, 1 if more data is needed for the full message, or
397  * -1 on error
398  */
eap_peer_tls_reassemble_fragment(struct eap_ssl_data * data,const struct wpabuf * in_data)399 static int eap_peer_tls_reassemble_fragment(struct eap_ssl_data *data,
400 					    const struct wpabuf *in_data)
401 {
402 	size_t tls_in_len, in_len;
403 
404 	tls_in_len = data->tls_in ? wpabuf_len(data->tls_in) : 0;
405 	in_len = in_data ? wpabuf_len(in_data) : 0;
406 
407 	if (tls_in_len + in_len == 0) {
408 		/* No message data received?! */
409 		wpa_printf(MSG_WARNING, "SSL: Invalid reassembly state: "
410 			   "tls_in_left=%lu tls_in_len=%lu in_len=%lu",
411 			   (unsigned long) data->tls_in_left,
412 			   (unsigned long) tls_in_len,
413 			   (unsigned long) in_len);
414 		eap_peer_tls_reset_input(data);
415 		return -1;
416 	}
417 
418 	if (tls_in_len + in_len > 65536) {
419 		/*
420 		 * Limit length to avoid rogue servers from causing large
421 		 * memory allocations.
422 		 */
423 		wpa_printf(MSG_INFO, "SSL: Too long TLS fragment (size over "
424 			   "64 kB)");
425 		eap_peer_tls_reset_input(data);
426 		return -1;
427 	}
428 
429 	if (in_len > data->tls_in_left) {
430 		/* Sender is doing something odd - reject message */
431 		wpa_printf(MSG_INFO, "SSL: more data than TLS message length "
432 			   "indicated");
433 		eap_peer_tls_reset_input(data);
434 		return -1;
435 	}
436 
437 	if (wpabuf_resize(&data->tls_in, in_len) < 0) {
438 		wpa_printf(MSG_INFO, "SSL: Could not allocate memory for TLS "
439 			   "data");
440 		eap_peer_tls_reset_input(data);
441 		return -1;
442 	}
443 	if (in_data)
444 		wpabuf_put_buf(data->tls_in, in_data);
445 	data->tls_in_left -= in_len;
446 
447 	if (data->tls_in_left > 0) {
448 		wpa_printf(MSG_DEBUG, "SSL: Need %lu bytes more input "
449 			   "data", (unsigned long) data->tls_in_left);
450 		return 1;
451 	}
452 
453 	return 0;
454 }
455 
456 
457 /**
458  * eap_peer_tls_data_reassemble - Reassemble TLS data
459  * @data: Data for TLS processing
460  * @in_data: Next incoming TLS segment
461  * @need_more_input: Variable for returning whether more input data is needed
462  * to reassemble this TLS packet
463  * Returns: Pointer to output data, %NULL on error or when more data is needed
464  * for the full message (in which case, *need_more_input is also set to 1).
465  *
466  * This function reassembles TLS fragments. Caller must not free the returned
467  * data buffer since an internal pointer to it is maintained.
468  */
eap_peer_tls_data_reassemble(struct eap_ssl_data * data,const struct wpabuf * in_data,int * need_more_input)469 static const struct wpabuf * eap_peer_tls_data_reassemble(
470 	struct eap_ssl_data *data, const struct wpabuf *in_data,
471 	int *need_more_input)
472 {
473 	*need_more_input = 0;
474 
475 	if (data->tls_in_left > wpabuf_len(in_data) || data->tls_in) {
476 		/* Message has fragments */
477 		int res = eap_peer_tls_reassemble_fragment(data, in_data);
478 		if (res) {
479 			if (res == 1)
480 				*need_more_input = 1;
481 			return NULL;
482 		}
483 
484 		/* Message is now fully reassembled. */
485 	} else {
486 		/* No fragments in this message, so just make a copy of it. */
487 		data->tls_in_left = 0;
488 		data->tls_in = wpabuf_dup(in_data);
489 		if (data->tls_in == NULL)
490 			return NULL;
491 	}
492 
493 	return data->tls_in;
494 }
495 
496 
497 /**
498  * eap_tls_process_input - Process incoming TLS message
499  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
500  * @data: Data for TLS processing
501  * @in_data: Message received from the server
502  * @in_len: Length of in_data
503  * @out_data: Buffer for returning a pointer to application data (if available)
504  * Returns: 0 on success, 1 if more input data is needed, 2 if application data
505  * is available, -1 on failure
506  */
eap_tls_process_input(struct eap_sm * sm,struct eap_ssl_data * data,const u8 * in_data,size_t in_len,struct wpabuf ** out_data)507 static int eap_tls_process_input(struct eap_sm *sm, struct eap_ssl_data *data,
508 				 const u8 *in_data, size_t in_len,
509 				 struct wpabuf **out_data)
510 {
511 	const struct wpabuf *msg;
512 	int need_more_input;
513 	struct wpabuf *appl_data;
514 	struct wpabuf buf;
515 
516 	wpabuf_set(&buf, in_data, in_len);
517 	msg = eap_peer_tls_data_reassemble(data, &buf, &need_more_input);
518 	if (msg == NULL)
519 		return need_more_input ? 1 : -1;
520 
521 	/* Full TLS message reassembled - continue handshake processing */
522 	if (data->tls_out) {
523 		/* This should not happen.. */
524 		wpa_printf(MSG_INFO, "SSL: eap_tls_process_input - pending "
525 			   "tls_out data even though tls_out_len = 0");
526 		wpabuf_free(data->tls_out);
527 		WPA_ASSERT(data->tls_out == NULL);
528 	}
529 	appl_data = NULL;
530 	data->tls_out = tls_connection_handshake(data->ssl_ctx, data->conn,
531 						 msg, &appl_data);
532 
533 	eap_peer_tls_reset_input(data);
534 
535 	if (appl_data &&
536 	    tls_connection_established(data->ssl_ctx, data->conn) &&
537 	    !tls_connection_get_failed(data->ssl_ctx, data->conn)) {
538 		wpa_hexdump_buf_key(MSG_MSGDUMP, "SSL: Application data",
539 				    appl_data);
540 		*out_data = appl_data;
541 		return 2;
542 	}
543 
544 	wpabuf_free(appl_data);
545 
546 	return 0;
547 }
548 
549 
550 /**
551  * eap_tls_process_output - Process outgoing TLS message
552  * @data: Data for TLS processing
553  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
554  * @peap_version: Version number for EAP-PEAP/TTLS
555  * @id: EAP identifier for the response
556  * @ret: Return value to use on success
557  * @out_data: Buffer for returning the allocated output buffer
558  * Returns: ret (0 or 1) on success, -1 on failure
559  */
eap_tls_process_output(struct eap_ssl_data * data,EapType eap_type,int peap_version,u8 id,int ret,struct wpabuf ** out_data)560 static int eap_tls_process_output(struct eap_ssl_data *data, EapType eap_type,
561 				  int peap_version, u8 id, int ret,
562 				  struct wpabuf **out_data)
563 {
564 	size_t len;
565 	u8 *flags;
566 	int more_fragments, length_included;
567 
568 	if (data->tls_out == NULL)
569 		return -1;
570 	len = wpabuf_len(data->tls_out) - data->tls_out_pos;
571 	wpa_printf(MSG_DEBUG, "SSL: %lu bytes left to be sent out (of total "
572 		   "%lu bytes)",
573 		   (unsigned long) len,
574 		   (unsigned long) wpabuf_len(data->tls_out));
575 
576 	/*
577 	 * Limit outgoing message to the configured maximum size. Fragment
578 	 * message if needed.
579 	 */
580 	if (len > data->tls_out_limit) {
581 		more_fragments = 1;
582 		len = data->tls_out_limit;
583 		wpa_printf(MSG_DEBUG, "SSL: sending %lu bytes, more fragments "
584 			   "will follow", (unsigned long) len);
585 	} else
586 		more_fragments = 0;
587 
588 	length_included = data->tls_out_pos == 0 &&
589 		(wpabuf_len(data->tls_out) > data->tls_out_limit ||
590 		 data->include_tls_length);
591 	if (!length_included &&
592 	    eap_type == EAP_TYPE_PEAP && peap_version == 0 &&
593 	    !tls_connection_established(data->eap->ssl_ctx, data->conn)) {
594 		/*
595 		 * Windows Server 2008 NPS really wants to have the TLS Message
596 		 * length included in phase 0 even for unfragmented frames or
597 		 * it will get very confused with Compound MAC calculation and
598 		 * Outer TLVs.
599 		 */
600 		length_included = 1;
601 	}
602 
603 	*out_data = eap_tls_msg_alloc(eap_type, 1 + length_included * 4 + len,
604 				      EAP_CODE_RESPONSE, id);
605 	if (*out_data == NULL)
606 		return -1;
607 
608 	flags = wpabuf_put(*out_data, 1);
609 	*flags = peap_version;
610 	if (more_fragments)
611 		*flags |= EAP_TLS_FLAGS_MORE_FRAGMENTS;
612 	if (length_included) {
613 		*flags |= EAP_TLS_FLAGS_LENGTH_INCLUDED;
614 		wpabuf_put_be32(*out_data, wpabuf_len(data->tls_out));
615 	}
616 
617 	wpabuf_put_data(*out_data,
618 			wpabuf_head_u8(data->tls_out) + data->tls_out_pos,
619 			len);
620 	data->tls_out_pos += len;
621 
622 	if (!more_fragments)
623 		eap_peer_tls_reset_output(data);
624 
625 	return ret;
626 }
627 
628 
629 /**
630  * eap_peer_tls_process_helper - Process TLS handshake message
631  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
632  * @data: Data for TLS processing
633  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
634  * @peap_version: Version number for EAP-PEAP/TTLS
635  * @id: EAP identifier for the response
636  * @in_data: Message received from the server
637  * @in_len: Length of in_data
638  * @out_data: Buffer for returning a pointer to the response message
639  * Returns: 0 on success, 1 if more input data is needed, 2 if application data
640  * is available, or -1 on failure
641  *
642  * This function can be used to process TLS handshake messages. It reassembles
643  * the received fragments and uses a TLS library to process the messages. The
644  * response data from the TLS library is fragmented to suitable output messages
645  * that the caller can send out.
646  *
647  * out_data is used to return the response message if the return value of this
648  * function is 0, 2, or -1. In case of failure, the message is likely a TLS
649  * alarm message. The caller is responsible for freeing the allocated buffer if
650  * *out_data is not %NULL.
651  *
652  * This function is called for each received TLS message during the TLS
653  * handshake after eap_peer_tls_process_init() call and possible processing of
654  * TLS Flags field. Once the handshake has been completed, i.e., when
655  * tls_connection_established() returns 1, EAP method specific decrypting of
656  * the tunneled data is used.
657  */
eap_peer_tls_process_helper(struct eap_sm * sm,struct eap_ssl_data * data,EapType eap_type,int peap_version,u8 id,const u8 * in_data,size_t in_len,struct wpabuf ** out_data)658 int eap_peer_tls_process_helper(struct eap_sm *sm, struct eap_ssl_data *data,
659 				EapType eap_type, int peap_version,
660 				u8 id, const u8 *in_data, size_t in_len,
661 				struct wpabuf **out_data)
662 {
663 	int ret = 0;
664 
665 	*out_data = NULL;
666 
667 	if (data->tls_out && wpabuf_len(data->tls_out) > 0 && in_len > 0) {
668 		wpa_printf(MSG_DEBUG, "SSL: Received non-ACK when output "
669 			   "fragments are waiting to be sent out");
670 		return -1;
671 	}
672 
673 	if (data->tls_out == NULL || wpabuf_len(data->tls_out) == 0) {
674 		/*
675 		 * No more data to send out - expect to receive more data from
676 		 * the AS.
677 		 */
678 		int res = eap_tls_process_input(sm, data, in_data, in_len,
679 						out_data);
680 		if (res) {
681 			/*
682 			 * Input processing failed (res = -1) or more data is
683 			 * needed (res = 1).
684 			 */
685 			return res;
686 		}
687 
688 		/*
689 		 * The incoming message has been reassembled and processed. The
690 		 * response was allocated into data->tls_out buffer.
691 		 */
692 	}
693 
694 	if (data->tls_out == NULL) {
695 		/*
696 		 * No outgoing fragments remaining from the previous message
697 		 * and no new message generated. This indicates an error in TLS
698 		 * processing.
699 		 */
700 		eap_peer_tls_reset_output(data);
701 		return -1;
702 	}
703 
704 	if (tls_connection_get_failed(data->ssl_ctx, data->conn)) {
705 		/* TLS processing has failed - return error */
706 		wpa_printf(MSG_DEBUG, "SSL: Failed - tls_out available to "
707 			   "report error");
708 		ret = -1;
709 		/* TODO: clean pin if engine used? */
710 	}
711 
712 	if (data->tls_out == NULL || wpabuf_len(data->tls_out) == 0) {
713 		/*
714 		 * TLS negotiation should now be complete since all other cases
715 		 * needing more data should have been caught above based on
716 		 * the TLS Message Length field.
717 		 */
718 		wpa_printf(MSG_DEBUG, "SSL: No data to be sent out");
719 		wpabuf_free(data->tls_out);
720 		data->tls_out = NULL;
721 		return 1;
722 	}
723 
724 	/* Send the pending message (in fragments, if needed). */
725 	return eap_tls_process_output(data, eap_type, peap_version, id, ret,
726 				      out_data);
727 }
728 
729 
730 /**
731  * eap_peer_tls_build_ack - Build a TLS ACK frame
732  * @id: EAP identifier for the response
733  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
734  * @peap_version: Version number for EAP-PEAP/TTLS
735  * Returns: Pointer to the allocated ACK frame or %NULL on failure
736  */
eap_peer_tls_build_ack(u8 id,EapType eap_type,int peap_version)737 struct wpabuf * eap_peer_tls_build_ack(u8 id, EapType eap_type,
738 				       int peap_version)
739 {
740 	struct wpabuf *resp;
741 
742 	resp = eap_tls_msg_alloc(eap_type, 1, EAP_CODE_RESPONSE, id);
743 	if (resp == NULL)
744 		return NULL;
745 	wpa_printf(MSG_DEBUG, "SSL: Building ACK (type=%d id=%d ver=%d)",
746 		   (int) eap_type, id, peap_version);
747 	wpabuf_put_u8(resp, peap_version); /* Flags */
748 	return resp;
749 }
750 
751 
752 /**
753  * eap_peer_tls_reauth_init - Re-initialize shared TLS for session resumption
754  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
755  * @data: Data for TLS processing
756  * Returns: 0 on success, -1 on failure
757  */
eap_peer_tls_reauth_init(struct eap_sm * sm,struct eap_ssl_data * data)758 int eap_peer_tls_reauth_init(struct eap_sm *sm, struct eap_ssl_data *data)
759 {
760 	eap_peer_tls_reset_input(data);
761 	eap_peer_tls_reset_output(data);
762 	return tls_connection_shutdown(data->ssl_ctx, data->conn);
763 }
764 
765 
766 /**
767  * eap_peer_tls_status - Get TLS status
768  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
769  * @data: Data for TLS processing
770  * @buf: Buffer for status information
771  * @buflen: Maximum buffer length
772  * @verbose: Whether to include verbose status information
773  * Returns: Number of bytes written to buf.
774  */
eap_peer_tls_status(struct eap_sm * sm,struct eap_ssl_data * data,char * buf,size_t buflen,int verbose)775 int eap_peer_tls_status(struct eap_sm *sm, struct eap_ssl_data *data,
776 			char *buf, size_t buflen, int verbose)
777 {
778 	char name[128];
779 	int len = 0, ret;
780 
781 	if (tls_get_cipher(data->ssl_ctx, data->conn, name, sizeof(name)) == 0)
782 	{
783 		ret = os_snprintf(buf + len, buflen - len,
784 				  "EAP TLS cipher=%s\n", name);
785 		if (ret < 0 || (size_t) ret >= buflen - len)
786 			return len;
787 		len += ret;
788 	}
789 
790 	return len;
791 }
792 
793 
794 /**
795  * eap_peer_tls_process_init - Initial validation/processing of EAP requests
796  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
797  * @data: Data for TLS processing
798  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
799  * @ret: Return values from EAP request validation and processing
800  * @reqData: EAP request to be processed (eapReqData)
801  * @len: Buffer for returning length of the remaining payload
802  * @flags: Buffer for returning TLS flags
803  * Returns: Pointer to payload after TLS flags and length or %NULL on failure
804  *
805  * This function validates the EAP header and processes the optional TLS
806  * Message Length field. If this is the first fragment of a TLS message, the
807  * TLS reassembly code is initialized to receive the indicated number of bytes.
808  *
809  * EAP-TLS, EAP-PEAP, EAP-TTLS, and EAP-FAST methods are expected to use this
810  * function as the first step in processing received messages. They will need
811  * to process the flags (apart from Message Length Included) that are returned
812  * through the flags pointer and the message payload that will be returned (and
813  * the length is returned through the len pointer). Return values (ret) are set
814  * for continuation of EAP method processing. The caller is responsible for
815  * setting these to indicate completion (either success or failure) based on
816  * the authentication result.
817  */
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)818 const u8 * eap_peer_tls_process_init(struct eap_sm *sm,
819 				     struct eap_ssl_data *data,
820 				     EapType eap_type,
821 				     struct eap_method_ret *ret,
822 				     const struct wpabuf *reqData,
823 				     size_t *len, u8 *flags)
824 {
825 	const u8 *pos;
826 	size_t left;
827 	unsigned int tls_msg_len;
828 
829 	if (tls_get_errors(data->ssl_ctx)) {
830 		wpa_printf(MSG_INFO, "SSL: TLS errors detected");
831 		ret->ignore = TRUE;
832 		return NULL;
833 	}
834 
835 	if (eap_type == EAP_UNAUTH_TLS_TYPE)
836 		pos = eap_hdr_validate(EAP_VENDOR_UNAUTH_TLS,
837 				       EAP_VENDOR_TYPE_UNAUTH_TLS, reqData,
838 				       &left);
839 	else
840 		pos = eap_hdr_validate(EAP_VENDOR_IETF, eap_type, reqData,
841 				       &left);
842 	if (pos == NULL) {
843 		ret->ignore = TRUE;
844 		return NULL;
845 	}
846 	if (left == 0) {
847 		wpa_printf(MSG_DEBUG, "SSL: Invalid TLS message: no Flags "
848 			   "octet included");
849 		if (!sm->workaround) {
850 			ret->ignore = TRUE;
851 			return NULL;
852 		}
853 
854 		wpa_printf(MSG_DEBUG, "SSL: Workaround - assume no Flags "
855 			   "indicates ACK frame");
856 		*flags = 0;
857 	} else {
858 		*flags = *pos++;
859 		left--;
860 	}
861 	wpa_printf(MSG_DEBUG, "SSL: Received packet(len=%lu) - "
862 		   "Flags 0x%02x", (unsigned long) wpabuf_len(reqData),
863 		   *flags);
864 	if (*flags & EAP_TLS_FLAGS_LENGTH_INCLUDED) {
865 		if (left < 4) {
866 			wpa_printf(MSG_INFO, "SSL: Short frame with TLS "
867 				   "length");
868 			ret->ignore = TRUE;
869 			return NULL;
870 		}
871 		tls_msg_len = WPA_GET_BE32(pos);
872 		wpa_printf(MSG_DEBUG, "SSL: TLS Message Length: %d",
873 			   tls_msg_len);
874 		if (data->tls_in_left == 0) {
875 			data->tls_in_total = tls_msg_len;
876 			data->tls_in_left = tls_msg_len;
877 			wpabuf_free(data->tls_in);
878 			data->tls_in = NULL;
879 		}
880 		pos += 4;
881 		left -= 4;
882 
883 		if (left > tls_msg_len) {
884 			wpa_printf(MSG_INFO, "SSL: TLS Message Length (%d "
885 				   "bytes) smaller than this fragment (%d "
886 				   "bytes)", (int) tls_msg_len, (int) left);
887 			ret->ignore = TRUE;
888 			return NULL;
889 		}
890 	}
891 
892 	ret->ignore = FALSE;
893 	ret->methodState = METHOD_MAY_CONT;
894 	ret->decision = DECISION_FAIL;
895 	ret->allowNotifications = TRUE;
896 
897 	*len = left;
898 	return pos;
899 }
900 
901 
902 /**
903  * eap_peer_tls_reset_input - Reset input buffers
904  * @data: Data for TLS processing
905  *
906  * This function frees any allocated memory for input buffers and resets input
907  * state.
908  */
eap_peer_tls_reset_input(struct eap_ssl_data * data)909 void eap_peer_tls_reset_input(struct eap_ssl_data *data)
910 {
911 	data->tls_in_left = data->tls_in_total = 0;
912 	wpabuf_free(data->tls_in);
913 	data->tls_in = NULL;
914 }
915 
916 
917 /**
918  * eap_peer_tls_reset_output - Reset output buffers
919  * @data: Data for TLS processing
920  *
921  * This function frees any allocated memory for output buffers and resets
922  * output state.
923  */
eap_peer_tls_reset_output(struct eap_ssl_data * data)924 void eap_peer_tls_reset_output(struct eap_ssl_data *data)
925 {
926 	data->tls_out_pos = 0;
927 	wpabuf_free(data->tls_out);
928 	data->tls_out = NULL;
929 }
930 
931 
932 /**
933  * eap_peer_tls_decrypt - Decrypt received phase 2 TLS message
934  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
935  * @data: Data for TLS processing
936  * @in_data: Message received from the server
937  * @in_decrypted: Buffer for returning a pointer to the decrypted message
938  * Returns: 0 on success, 1 if more input data is needed, or -1 on failure
939  */
eap_peer_tls_decrypt(struct eap_sm * sm,struct eap_ssl_data * data,const struct wpabuf * in_data,struct wpabuf ** in_decrypted)940 int eap_peer_tls_decrypt(struct eap_sm *sm, struct eap_ssl_data *data,
941 			 const struct wpabuf *in_data,
942 			 struct wpabuf **in_decrypted)
943 {
944 	const struct wpabuf *msg;
945 	int need_more_input;
946 
947 	msg = eap_peer_tls_data_reassemble(data, in_data, &need_more_input);
948 	if (msg == NULL)
949 		return need_more_input ? 1 : -1;
950 
951 	*in_decrypted = tls_connection_decrypt(data->ssl_ctx, data->conn, msg);
952 	eap_peer_tls_reset_input(data);
953 	if (*in_decrypted == NULL) {
954 		wpa_printf(MSG_INFO, "SSL: Failed to decrypt Phase 2 data");
955 		return -1;
956 	}
957 	return 0;
958 }
959 
960 
961 /**
962  * eap_peer_tls_encrypt - Encrypt phase 2 TLS message
963  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
964  * @data: Data for TLS processing
965  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
966  * @peap_version: Version number for EAP-PEAP/TTLS
967  * @id: EAP identifier for the response
968  * @in_data: Plaintext phase 2 data to encrypt or %NULL to continue fragments
969  * @out_data: Buffer for returning a pointer to the encrypted response message
970  * Returns: 0 on success, -1 on failure
971  */
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)972 int eap_peer_tls_encrypt(struct eap_sm *sm, struct eap_ssl_data *data,
973 			 EapType eap_type, int peap_version, u8 id,
974 			 const struct wpabuf *in_data,
975 			 struct wpabuf **out_data)
976 {
977 	if (in_data) {
978 		eap_peer_tls_reset_output(data);
979 		data->tls_out = tls_connection_encrypt(data->ssl_ctx,
980 						       data->conn, in_data);
981 		if (data->tls_out == NULL) {
982 			wpa_printf(MSG_INFO, "SSL: Failed to encrypt Phase 2 "
983 				   "data (in_len=%lu)",
984 				   (unsigned long) wpabuf_len(in_data));
985 			eap_peer_tls_reset_output(data);
986 			return -1;
987 		}
988 	}
989 
990 	return eap_tls_process_output(data, eap_type, peap_version, id, 0,
991 				      out_data);
992 }
993 
994 
995 /**
996  * eap_peer_select_phase2_methods - Select phase 2 EAP method
997  * @config: Pointer to the network configuration
998  * @prefix: 'phase2' configuration prefix, e.g., "auth="
999  * @types: Buffer for returning allocated list of allowed EAP methods
1000  * @num_types: Buffer for returning number of allocated EAP methods
1001  * Returns: 0 on success, -1 on failure
1002  *
1003  * This function is used to parse EAP method list and select allowed methods
1004  * for Phase2 authentication.
1005  */
eap_peer_select_phase2_methods(struct eap_peer_config * config,const char * prefix,struct eap_method_type ** types,size_t * num_types)1006 int eap_peer_select_phase2_methods(struct eap_peer_config *config,
1007 				   const char *prefix,
1008 				   struct eap_method_type **types,
1009 				   size_t *num_types)
1010 {
1011 	char *start, *pos, *buf;
1012 	struct eap_method_type *methods = NULL, *_methods;
1013 	u8 method;
1014 	size_t num_methods = 0, prefix_len;
1015 
1016 	if (config == NULL || config->phase2 == NULL)
1017 		goto get_defaults;
1018 
1019 	start = buf = os_strdup(config->phase2);
1020 	if (buf == NULL)
1021 		return -1;
1022 
1023 	prefix_len = os_strlen(prefix);
1024 
1025 	while (start && *start != '\0') {
1026 		int vendor;
1027 		pos = os_strstr(start, prefix);
1028 		if (pos == NULL)
1029 			break;
1030 		if (start != pos && *(pos - 1) != ' ') {
1031 			start = pos + prefix_len;
1032 			continue;
1033 		}
1034 
1035 		start = pos + prefix_len;
1036 		pos = os_strchr(start, ' ');
1037 		if (pos)
1038 			*pos++ = '\0';
1039 		method = eap_get_phase2_type(start, &vendor);
1040 		if (vendor == EAP_VENDOR_IETF && method == EAP_TYPE_NONE) {
1041 			wpa_printf(MSG_ERROR, "TLS: Unsupported Phase2 EAP "
1042 				   "method '%s'", start);
1043 		} else {
1044 			num_methods++;
1045 			_methods = os_realloc_array(methods, num_methods,
1046 						    sizeof(*methods));
1047 			if (_methods == NULL) {
1048 				os_free(methods);
1049 				os_free(buf);
1050 				return -1;
1051 			}
1052 			methods = _methods;
1053 			methods[num_methods - 1].vendor = vendor;
1054 			methods[num_methods - 1].method = method;
1055 		}
1056 
1057 		start = pos;
1058 	}
1059 
1060 	os_free(buf);
1061 
1062 get_defaults:
1063 	if (methods == NULL)
1064 		methods = eap_get_phase2_types(config, &num_methods);
1065 
1066 	if (methods == NULL) {
1067 		wpa_printf(MSG_ERROR, "TLS: No Phase2 EAP methods available");
1068 		return -1;
1069 	}
1070 	wpa_hexdump(MSG_DEBUG, "TLS: Phase2 EAP types",
1071 		    (u8 *) methods,
1072 		    num_methods * sizeof(struct eap_method_type));
1073 
1074 	*types = methods;
1075 	*num_types = num_methods;
1076 
1077 	return 0;
1078 }
1079 
1080 
1081 /**
1082  * eap_peer_tls_phase2_nak - Generate EAP-Nak for Phase 2
1083  * @types: Buffer for returning allocated list of allowed EAP methods
1084  * @num_types: Buffer for returning number of allocated EAP methods
1085  * @hdr: EAP-Request header (and the following EAP type octet)
1086  * @resp: Buffer for returning the EAP-Nak message
1087  * Returns: 0 on success, -1 on failure
1088  */
eap_peer_tls_phase2_nak(struct eap_method_type * types,size_t num_types,struct eap_hdr * hdr,struct wpabuf ** resp)1089 int eap_peer_tls_phase2_nak(struct eap_method_type *types, size_t num_types,
1090 			    struct eap_hdr *hdr, struct wpabuf **resp)
1091 {
1092 	u8 *pos = (u8 *) (hdr + 1);
1093 	size_t i;
1094 
1095 	/* TODO: add support for expanded Nak */
1096 	wpa_printf(MSG_DEBUG, "TLS: Phase 2 Request: Nak type=%d", *pos);
1097 	wpa_hexdump(MSG_DEBUG, "TLS: Allowed Phase2 EAP types",
1098 		    (u8 *) types, num_types * sizeof(struct eap_method_type));
1099 	*resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_NAK, num_types,
1100 			      EAP_CODE_RESPONSE, hdr->identifier);
1101 	if (*resp == NULL)
1102 		return -1;
1103 
1104 	for (i = 0; i < num_types; i++) {
1105 		if (types[i].vendor == EAP_VENDOR_IETF &&
1106 		    types[i].method < 256)
1107 			wpabuf_put_u8(*resp, types[i].method);
1108 	}
1109 
1110 	eap_update_len(*resp);
1111 
1112 	return 0;
1113 }
1114