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1 /*
2  * EAP peer: EAP-TLS/PEAP/TTLS/FAST common functions
3  * Copyright (c) 2004-2012, 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 	data->conn = tls_connection_init(data->ssl_ctx);
168 	if (data->conn == NULL) {
169 		wpa_printf(MSG_INFO, "SSL: Failed to initialize new TLS "
170 			   "connection");
171 		return -1;
172 	}
173 
174 	res = tls_connection_set_params(data->ssl_ctx, data->conn, params);
175 	if (res == TLS_SET_PARAMS_ENGINE_PRV_INIT_FAILED) {
176 		/*
177 		 * At this point with the pkcs11 engine the PIN might be wrong.
178 		 * We reset the PIN in the configuration to be sure to not use
179 		 * it again and the calling function must request a new one.
180 		 */
181 		os_free(config->pin);
182 		config->pin = NULL;
183 	} else if (res == TLS_SET_PARAMS_ENGINE_PRV_VERIFY_FAILED) {
184 		wpa_printf(MSG_INFO, "TLS: Failed to load private key");
185 		/*
186 		 * We do not know exactly but maybe the PIN was wrong,
187 		 * so ask for a new one.
188 		 */
189 		os_free(config->pin);
190 		config->pin = NULL;
191 		eap_sm_request_pin(sm);
192 		sm->ignore = TRUE;
193 		tls_connection_deinit(data->ssl_ctx, data->conn);
194 		data->conn = NULL;
195 		return -1;
196 	} else if (res) {
197 		wpa_printf(MSG_INFO, "TLS: Failed to set TLS connection "
198 			   "parameters");
199 		tls_connection_deinit(data->ssl_ctx, data->conn);
200 		data->conn = NULL;
201 		return -1;
202 	}
203 
204 	return 0;
205 }
206 
207 
208 /**
209  * eap_peer_tls_ssl_init - Initialize shared TLS functionality
210  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
211  * @data: Data for TLS processing
212  * @config: Pointer to the network configuration
213  * @eap_type: EAP method used in Phase 1 (EAP_TYPE_TLS/PEAP/TTLS/FAST)
214  * Returns: 0 on success, -1 on failure
215  *
216  * This function is used to initialize shared TLS functionality for EAP-TLS,
217  * EAP-PEAP, EAP-TTLS, and EAP-FAST.
218  */
eap_peer_tls_ssl_init(struct eap_sm * sm,struct eap_ssl_data * data,struct eap_peer_config * config,u8 eap_type)219 int eap_peer_tls_ssl_init(struct eap_sm *sm, struct eap_ssl_data *data,
220 			  struct eap_peer_config *config, u8 eap_type)
221 {
222 	struct tls_connection_params params;
223 
224 	if (config == NULL)
225 		return -1;
226 
227 	data->eap = sm;
228 	data->eap_type = eap_type;
229 	data->phase2 = sm->init_phase2;
230 	data->ssl_ctx = sm->init_phase2 && sm->ssl_ctx2 ? sm->ssl_ctx2 :
231 		sm->ssl_ctx;
232 	if (eap_tls_params_from_conf(sm, data, &params, config, data->phase2) <
233 	    0)
234 		return -1;
235 
236 	if (eap_tls_init_connection(sm, data, config, &params) < 0)
237 		return -1;
238 
239 	data->tls_out_limit = config->fragment_size;
240 	if (data->phase2) {
241 		/* Limit the fragment size in the inner TLS authentication
242 		 * since the outer authentication with EAP-PEAP does not yet
243 		 * support fragmentation */
244 		if (data->tls_out_limit > 100)
245 			data->tls_out_limit -= 100;
246 	}
247 
248 	if (config->phase1 &&
249 	    os_strstr(config->phase1, "include_tls_length=1")) {
250 		wpa_printf(MSG_DEBUG, "TLS: Include TLS Message Length in "
251 			   "unfragmented packets");
252 		data->include_tls_length = 1;
253 	}
254 
255 	return 0;
256 }
257 
258 
259 /**
260  * eap_peer_tls_ssl_deinit - Deinitialize shared TLS functionality
261  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
262  * @data: Data for TLS processing
263  *
264  * This function deinitializes shared TLS functionality that was initialized
265  * with eap_peer_tls_ssl_init().
266  */
eap_peer_tls_ssl_deinit(struct eap_sm * sm,struct eap_ssl_data * data)267 void eap_peer_tls_ssl_deinit(struct eap_sm *sm, struct eap_ssl_data *data)
268 {
269 	tls_connection_deinit(data->ssl_ctx, data->conn);
270 	eap_peer_tls_reset_input(data);
271 	eap_peer_tls_reset_output(data);
272 }
273 
274 
275 /**
276  * eap_peer_tls_derive_key - Derive a key based on TLS session data
277  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
278  * @data: Data for TLS processing
279  * @label: Label string for deriving the keys, e.g., "client EAP encryption"
280  * @len: Length of the key material to generate (usually 64 for MSK)
281  * Returns: Pointer to allocated key on success or %NULL on failure
282  *
283  * This function uses TLS-PRF to generate pseudo-random data based on the TLS
284  * session data (client/server random and master key). Each key type may use a
285  * different label to bind the key usage into the generated material.
286  *
287  * The caller is responsible for freeing the returned buffer.
288  */
eap_peer_tls_derive_key(struct eap_sm * sm,struct eap_ssl_data * data,const char * label,size_t len)289 u8 * eap_peer_tls_derive_key(struct eap_sm *sm, struct eap_ssl_data *data,
290 			     const char *label, size_t len)
291 {
292 #ifndef CONFIG_FIPS
293 	struct tls_keys keys;
294 #endif /* CONFIG_FIPS */
295 	u8 *rnd = NULL, *out;
296 
297 	out = os_malloc(len);
298 	if (out == NULL)
299 		return NULL;
300 
301 	/* First, try to use TLS library function for PRF, if available. */
302 	if (tls_connection_prf(data->ssl_ctx, data->conn, label, 0, out, len)
303 	    == 0)
304 		return out;
305 
306 #ifndef CONFIG_FIPS
307 	/*
308 	 * TLS library did not support key generation, so get the needed TLS
309 	 * session parameters and use an internal implementation of TLS PRF to
310 	 * derive the key.
311 	 */
312 	if (tls_connection_get_keys(data->ssl_ctx, data->conn, &keys))
313 		goto fail;
314 
315 	if (keys.client_random == NULL || keys.server_random == NULL ||
316 	    keys.master_key == NULL)
317 		goto fail;
318 
319 	rnd = os_malloc(keys.client_random_len + keys.server_random_len);
320 	if (rnd == NULL)
321 		goto fail;
322 	os_memcpy(rnd, keys.client_random, keys.client_random_len);
323 	os_memcpy(rnd + keys.client_random_len, keys.server_random,
324 		  keys.server_random_len);
325 
326 	if (tls_prf_sha1_md5(keys.master_key, keys.master_key_len,
327 			     label, rnd, keys.client_random_len +
328 			     keys.server_random_len, out, len))
329 		goto fail;
330 
331 	os_free(rnd);
332 	return out;
333 
334 fail:
335 #endif /* CONFIG_FIPS */
336 	os_free(out);
337 	os_free(rnd);
338 	return NULL;
339 }
340 
341 
342 /**
343  * eap_peer_tls_derive_session_id - Derive a Session-Id based on TLS data
344  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
345  * @data: Data for TLS processing
346  * @eap_type: EAP method used in Phase 1 (EAP_TYPE_TLS/PEAP/TTLS/FAST)
347  * @len: Pointer to length of the session ID generated
348  * Returns: Pointer to allocated Session-Id on success or %NULL on failure
349  *
350  * This function derive the Session-Id based on the TLS session data
351  * (client/server random and method type).
352  *
353  * The caller is responsible for freeing the returned buffer.
354  */
eap_peer_tls_derive_session_id(struct eap_sm * sm,struct eap_ssl_data * data,u8 eap_type,size_t * len)355 u8 * eap_peer_tls_derive_session_id(struct eap_sm *sm,
356 				    struct eap_ssl_data *data, u8 eap_type,
357 				    size_t *len)
358 {
359 	struct tls_keys keys;
360 	u8 *out;
361 
362 	/*
363 	 * TLS library did not support session ID generation,
364 	 * so get the needed TLS session parameters
365 	 */
366 	if (tls_connection_get_keys(sm->ssl_ctx, data->conn, &keys))
367 		return NULL;
368 
369 	if (keys.client_random == NULL || keys.server_random == NULL ||
370 	    keys.master_key == NULL)
371 		return NULL;
372 
373 	*len = 1 + keys.client_random_len + keys.server_random_len;
374 	out = os_malloc(*len);
375 	if (out == NULL)
376 		return NULL;
377 
378 	/* Session-Id = EAP type || client.random || server.random */
379 	out[0] = eap_type;
380 	os_memcpy(out + 1, keys.client_random, keys.client_random_len);
381 	os_memcpy(out + 1 + keys.client_random_len, keys.server_random,
382 	          keys.server_random_len);
383 
384 	return out;
385 }
386 
387 
388 /**
389  * eap_peer_tls_reassemble_fragment - Reassemble a received fragment
390  * @data: Data for TLS processing
391  * @in_data: Next incoming TLS segment
392  * Returns: 0 on success, 1 if more data is needed for the full message, or
393  * -1 on error
394  */
eap_peer_tls_reassemble_fragment(struct eap_ssl_data * data,const struct wpabuf * in_data)395 static int eap_peer_tls_reassemble_fragment(struct eap_ssl_data *data,
396 					    const struct wpabuf *in_data)
397 {
398 	size_t tls_in_len, in_len;
399 
400 	tls_in_len = data->tls_in ? wpabuf_len(data->tls_in) : 0;
401 	in_len = in_data ? wpabuf_len(in_data) : 0;
402 
403 	if (tls_in_len + in_len == 0) {
404 		/* No message data received?! */
405 		wpa_printf(MSG_WARNING, "SSL: Invalid reassembly state: "
406 			   "tls_in_left=%lu tls_in_len=%lu in_len=%lu",
407 			   (unsigned long) data->tls_in_left,
408 			   (unsigned long) tls_in_len,
409 			   (unsigned long) in_len);
410 		eap_peer_tls_reset_input(data);
411 		return -1;
412 	}
413 
414 	if (tls_in_len + in_len > 65536) {
415 		/*
416 		 * Limit length to avoid rogue servers from causing large
417 		 * memory allocations.
418 		 */
419 		wpa_printf(MSG_INFO, "SSL: Too long TLS fragment (size over "
420 			   "64 kB)");
421 		eap_peer_tls_reset_input(data);
422 		return -1;
423 	}
424 
425 	if (in_len > data->tls_in_left) {
426 		/* Sender is doing something odd - reject message */
427 		wpa_printf(MSG_INFO, "SSL: more data than TLS message length "
428 			   "indicated");
429 		eap_peer_tls_reset_input(data);
430 		return -1;
431 	}
432 
433 	if (wpabuf_resize(&data->tls_in, in_len) < 0) {
434 		wpa_printf(MSG_INFO, "SSL: Could not allocate memory for TLS "
435 			   "data");
436 		eap_peer_tls_reset_input(data);
437 		return -1;
438 	}
439 	if (in_data)
440 		wpabuf_put_buf(data->tls_in, in_data);
441 	data->tls_in_left -= in_len;
442 
443 	if (data->tls_in_left > 0) {
444 		wpa_printf(MSG_DEBUG, "SSL: Need %lu bytes more input "
445 			   "data", (unsigned long) data->tls_in_left);
446 		return 1;
447 	}
448 
449 	return 0;
450 }
451 
452 
453 /**
454  * eap_peer_tls_data_reassemble - Reassemble TLS data
455  * @data: Data for TLS processing
456  * @in_data: Next incoming TLS segment
457  * @need_more_input: Variable for returning whether more input data is needed
458  * to reassemble this TLS packet
459  * Returns: Pointer to output data, %NULL on error or when more data is needed
460  * for the full message (in which case, *need_more_input is also set to 1).
461  *
462  * This function reassembles TLS fragments. Caller must not free the returned
463  * data buffer since an internal pointer to it is maintained.
464  */
eap_peer_tls_data_reassemble(struct eap_ssl_data * data,const struct wpabuf * in_data,int * need_more_input)465 static const struct wpabuf * eap_peer_tls_data_reassemble(
466 	struct eap_ssl_data *data, const struct wpabuf *in_data,
467 	int *need_more_input)
468 {
469 	*need_more_input = 0;
470 
471 	if (data->tls_in_left > wpabuf_len(in_data) || data->tls_in) {
472 		/* Message has fragments */
473 		int res = eap_peer_tls_reassemble_fragment(data, in_data);
474 		if (res) {
475 			if (res == 1)
476 				*need_more_input = 1;
477 			return NULL;
478 		}
479 
480 		/* Message is now fully reassembled. */
481 	} else {
482 		/* No fragments in this message, so just make a copy of it. */
483 		data->tls_in_left = 0;
484 		data->tls_in = wpabuf_dup(in_data);
485 		if (data->tls_in == NULL)
486 			return NULL;
487 	}
488 
489 	return data->tls_in;
490 }
491 
492 
493 /**
494  * eap_tls_process_input - Process incoming TLS message
495  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
496  * @data: Data for TLS processing
497  * @in_data: Message received from the server
498  * @in_len: Length of in_data
499  * @out_data: Buffer for returning a pointer to application data (if available)
500  * Returns: 0 on success, 1 if more input data is needed, 2 if application data
501  * is available, -1 on failure
502  */
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)503 static int eap_tls_process_input(struct eap_sm *sm, struct eap_ssl_data *data,
504 				 const u8 *in_data, size_t in_len,
505 				 struct wpabuf **out_data)
506 {
507 	const struct wpabuf *msg;
508 	int need_more_input;
509 	struct wpabuf *appl_data;
510 	struct wpabuf buf;
511 
512 	wpabuf_set(&buf, in_data, in_len);
513 	msg = eap_peer_tls_data_reassemble(data, &buf, &need_more_input);
514 	if (msg == NULL)
515 		return need_more_input ? 1 : -1;
516 
517 	/* Full TLS message reassembled - continue handshake processing */
518 	if (data->tls_out) {
519 		/* This should not happen.. */
520 		wpa_printf(MSG_INFO, "SSL: eap_tls_process_input - pending "
521 			   "tls_out data even though tls_out_len = 0");
522 		wpabuf_free(data->tls_out);
523 		WPA_ASSERT(data->tls_out == NULL);
524 	}
525 	appl_data = NULL;
526 	data->tls_out = tls_connection_handshake(data->ssl_ctx, data->conn,
527 						 msg, &appl_data);
528 
529 	eap_peer_tls_reset_input(data);
530 
531 	if (appl_data &&
532 	    tls_connection_established(data->ssl_ctx, data->conn) &&
533 	    !tls_connection_get_failed(data->ssl_ctx, data->conn)) {
534 		wpa_hexdump_buf_key(MSG_MSGDUMP, "SSL: Application data",
535 				    appl_data);
536 		*out_data = appl_data;
537 		return 2;
538 	}
539 
540 	wpabuf_free(appl_data);
541 
542 	return 0;
543 }
544 
545 
546 /**
547  * eap_tls_process_output - Process outgoing TLS message
548  * @data: Data for TLS processing
549  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
550  * @peap_version: Version number for EAP-PEAP/TTLS
551  * @id: EAP identifier for the response
552  * @ret: Return value to use on success
553  * @out_data: Buffer for returning the allocated output buffer
554  * Returns: ret (0 or 1) on success, -1 on failure
555  */
eap_tls_process_output(struct eap_ssl_data * data,EapType eap_type,int peap_version,u8 id,int ret,struct wpabuf ** out_data)556 static int eap_tls_process_output(struct eap_ssl_data *data, EapType eap_type,
557 				  int peap_version, u8 id, int ret,
558 				  struct wpabuf **out_data)
559 {
560 	size_t len;
561 	u8 *flags;
562 	int more_fragments, length_included;
563 
564 	if (data->tls_out == NULL)
565 		return -1;
566 	len = wpabuf_len(data->tls_out) - data->tls_out_pos;
567 	wpa_printf(MSG_DEBUG, "SSL: %lu bytes left to be sent out (of total "
568 		   "%lu bytes)",
569 		   (unsigned long) len,
570 		   (unsigned long) wpabuf_len(data->tls_out));
571 
572 	/*
573 	 * Limit outgoing message to the configured maximum size. Fragment
574 	 * message if needed.
575 	 */
576 	if (len > data->tls_out_limit) {
577 		more_fragments = 1;
578 		len = data->tls_out_limit;
579 		wpa_printf(MSG_DEBUG, "SSL: sending %lu bytes, more fragments "
580 			   "will follow", (unsigned long) len);
581 	} else
582 		more_fragments = 0;
583 
584 	length_included = data->tls_out_pos == 0 &&
585 		(wpabuf_len(data->tls_out) > data->tls_out_limit ||
586 		 data->include_tls_length);
587 	if (!length_included &&
588 	    eap_type == EAP_TYPE_PEAP && peap_version == 0 &&
589 	    !tls_connection_established(data->eap->ssl_ctx, data->conn)) {
590 		/*
591 		 * Windows Server 2008 NPS really wants to have the TLS Message
592 		 * length included in phase 0 even for unfragmented frames or
593 		 * it will get very confused with Compound MAC calculation and
594 		 * Outer TLVs.
595 		 */
596 		length_included = 1;
597 	}
598 
599 	*out_data = eap_tls_msg_alloc(eap_type, 1 + length_included * 4 + len,
600 				      EAP_CODE_RESPONSE, id);
601 	if (*out_data == NULL)
602 		return -1;
603 
604 	flags = wpabuf_put(*out_data, 1);
605 	*flags = peap_version;
606 	if (more_fragments)
607 		*flags |= EAP_TLS_FLAGS_MORE_FRAGMENTS;
608 	if (length_included) {
609 		*flags |= EAP_TLS_FLAGS_LENGTH_INCLUDED;
610 		wpabuf_put_be32(*out_data, wpabuf_len(data->tls_out));
611 	}
612 
613 	wpabuf_put_data(*out_data,
614 			wpabuf_head_u8(data->tls_out) + data->tls_out_pos,
615 			len);
616 	data->tls_out_pos += len;
617 
618 	if (!more_fragments)
619 		eap_peer_tls_reset_output(data);
620 
621 	return ret;
622 }
623 
624 
625 /**
626  * eap_peer_tls_process_helper - Process TLS handshake message
627  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
628  * @data: Data for TLS processing
629  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
630  * @peap_version: Version number for EAP-PEAP/TTLS
631  * @id: EAP identifier for the response
632  * @in_data: Message received from the server
633  * @in_len: Length of in_data
634  * @out_data: Buffer for returning a pointer to the response message
635  * Returns: 0 on success, 1 if more input data is needed, 2 if application data
636  * is available, or -1 on failure
637  *
638  * This function can be used to process TLS handshake messages. It reassembles
639  * the received fragments and uses a TLS library to process the messages. The
640  * response data from the TLS library is fragmented to suitable output messages
641  * that the caller can send out.
642  *
643  * out_data is used to return the response message if the return value of this
644  * function is 0, 2, or -1. In case of failure, the message is likely a TLS
645  * alarm message. The caller is responsible for freeing the allocated buffer if
646  * *out_data is not %NULL.
647  *
648  * This function is called for each received TLS message during the TLS
649  * handshake after eap_peer_tls_process_init() call and possible processing of
650  * TLS Flags field. Once the handshake has been completed, i.e., when
651  * tls_connection_established() returns 1, EAP method specific decrypting of
652  * the tunneled data is used.
653  */
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)654 int eap_peer_tls_process_helper(struct eap_sm *sm, struct eap_ssl_data *data,
655 				EapType eap_type, int peap_version,
656 				u8 id, const u8 *in_data, size_t in_len,
657 				struct wpabuf **out_data)
658 {
659 	int ret = 0;
660 
661 	*out_data = NULL;
662 
663 	if (data->tls_out && wpabuf_len(data->tls_out) > 0 && in_len > 0) {
664 		wpa_printf(MSG_DEBUG, "SSL: Received non-ACK when output "
665 			   "fragments are waiting to be sent out");
666 		return -1;
667 	}
668 
669 	if (data->tls_out == NULL || wpabuf_len(data->tls_out) == 0) {
670 		/*
671 		 * No more data to send out - expect to receive more data from
672 		 * the AS.
673 		 */
674 		int res = eap_tls_process_input(sm, data, in_data, in_len,
675 						out_data);
676 		if (res) {
677 			/*
678 			 * Input processing failed (res = -1) or more data is
679 			 * needed (res = 1).
680 			 */
681 			return res;
682 		}
683 
684 		/*
685 		 * The incoming message has been reassembled and processed. The
686 		 * response was allocated into data->tls_out buffer.
687 		 */
688 	}
689 
690 	if (data->tls_out == NULL) {
691 		/*
692 		 * No outgoing fragments remaining from the previous message
693 		 * and no new message generated. This indicates an error in TLS
694 		 * processing.
695 		 */
696 		eap_peer_tls_reset_output(data);
697 		return -1;
698 	}
699 
700 	if (tls_connection_get_failed(data->ssl_ctx, data->conn)) {
701 		/* TLS processing has failed - return error */
702 		wpa_printf(MSG_DEBUG, "SSL: Failed - tls_out available to "
703 			   "report error");
704 		ret = -1;
705 		/* TODO: clean pin if engine used? */
706 	}
707 
708 	if (data->tls_out == NULL || wpabuf_len(data->tls_out) == 0) {
709 		/*
710 		 * TLS negotiation should now be complete since all other cases
711 		 * needing more data should have been caught above based on
712 		 * the TLS Message Length field.
713 		 */
714 		wpa_printf(MSG_DEBUG, "SSL: No data to be sent out");
715 		wpabuf_free(data->tls_out);
716 		data->tls_out = NULL;
717 		return 1;
718 	}
719 
720 	/* Send the pending message (in fragments, if needed). */
721 	return eap_tls_process_output(data, eap_type, peap_version, id, ret,
722 				      out_data);
723 }
724 
725 
726 /**
727  * eap_peer_tls_build_ack - Build a TLS ACK frame
728  * @id: EAP identifier for the response
729  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
730  * @peap_version: Version number for EAP-PEAP/TTLS
731  * Returns: Pointer to the allocated ACK frame or %NULL on failure
732  */
eap_peer_tls_build_ack(u8 id,EapType eap_type,int peap_version)733 struct wpabuf * eap_peer_tls_build_ack(u8 id, EapType eap_type,
734 				       int peap_version)
735 {
736 	struct wpabuf *resp;
737 
738 	resp = eap_tls_msg_alloc(eap_type, 1, EAP_CODE_RESPONSE, id);
739 	if (resp == NULL)
740 		return NULL;
741 	wpa_printf(MSG_DEBUG, "SSL: Building ACK (type=%d id=%d ver=%d)",
742 		   (int) eap_type, id, peap_version);
743 	wpabuf_put_u8(resp, peap_version); /* Flags */
744 	return resp;
745 }
746 
747 
748 /**
749  * eap_peer_tls_reauth_init - Re-initialize shared TLS for session resumption
750  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
751  * @data: Data for TLS processing
752  * Returns: 0 on success, -1 on failure
753  */
eap_peer_tls_reauth_init(struct eap_sm * sm,struct eap_ssl_data * data)754 int eap_peer_tls_reauth_init(struct eap_sm *sm, struct eap_ssl_data *data)
755 {
756 	eap_peer_tls_reset_input(data);
757 	eap_peer_tls_reset_output(data);
758 	return tls_connection_shutdown(data->ssl_ctx, data->conn);
759 }
760 
761 
762 /**
763  * eap_peer_tls_status - Get TLS status
764  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
765  * @data: Data for TLS processing
766  * @buf: Buffer for status information
767  * @buflen: Maximum buffer length
768  * @verbose: Whether to include verbose status information
769  * Returns: Number of bytes written to buf.
770  */
eap_peer_tls_status(struct eap_sm * sm,struct eap_ssl_data * data,char * buf,size_t buflen,int verbose)771 int eap_peer_tls_status(struct eap_sm *sm, struct eap_ssl_data *data,
772 			char *buf, size_t buflen, int verbose)
773 {
774 	char name[128];
775 	int len = 0, ret;
776 
777 	if (tls_get_cipher(data->ssl_ctx, data->conn, name, sizeof(name)) == 0)
778 	{
779 		ret = os_snprintf(buf + len, buflen - len,
780 				  "EAP TLS cipher=%s\n", name);
781 		if (ret < 0 || (size_t) ret >= buflen - len)
782 			return len;
783 		len += ret;
784 	}
785 
786 	return len;
787 }
788 
789 
790 /**
791  * eap_peer_tls_process_init - Initial validation/processing of EAP requests
792  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
793  * @data: Data for TLS processing
794  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
795  * @ret: Return values from EAP request validation and processing
796  * @reqData: EAP request to be processed (eapReqData)
797  * @len: Buffer for returning length of the remaining payload
798  * @flags: Buffer for returning TLS flags
799  * Returns: Pointer to payload after TLS flags and length or %NULL on failure
800  *
801  * This function validates the EAP header and processes the optional TLS
802  * Message Length field. If this is the first fragment of a TLS message, the
803  * TLS reassembly code is initialized to receive the indicated number of bytes.
804  *
805  * EAP-TLS, EAP-PEAP, EAP-TTLS, and EAP-FAST methods are expected to use this
806  * function as the first step in processing received messages. They will need
807  * to process the flags (apart from Message Length Included) that are returned
808  * through the flags pointer and the message payload that will be returned (and
809  * the length is returned through the len pointer). Return values (ret) are set
810  * for continuation of EAP method processing. The caller is responsible for
811  * setting these to indicate completion (either success or failure) based on
812  * the authentication result.
813  */
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)814 const u8 * eap_peer_tls_process_init(struct eap_sm *sm,
815 				     struct eap_ssl_data *data,
816 				     EapType eap_type,
817 				     struct eap_method_ret *ret,
818 				     const struct wpabuf *reqData,
819 				     size_t *len, u8 *flags)
820 {
821 	const u8 *pos;
822 	size_t left;
823 	unsigned int tls_msg_len;
824 
825 	if (tls_get_errors(data->ssl_ctx)) {
826 		wpa_printf(MSG_INFO, "SSL: TLS errors detected");
827 		ret->ignore = TRUE;
828 		return NULL;
829 	}
830 
831 	if (eap_type == EAP_UNAUTH_TLS_TYPE)
832 		pos = eap_hdr_validate(EAP_VENDOR_UNAUTH_TLS,
833 				       EAP_VENDOR_TYPE_UNAUTH_TLS, reqData,
834 				       &left);
835 	else
836 		pos = eap_hdr_validate(EAP_VENDOR_IETF, eap_type, reqData,
837 				       &left);
838 	if (pos == NULL) {
839 		ret->ignore = TRUE;
840 		return NULL;
841 	}
842 	if (left == 0) {
843 		wpa_printf(MSG_DEBUG, "SSL: Invalid TLS message: no Flags "
844 			   "octet included");
845 		if (!sm->workaround) {
846 			ret->ignore = TRUE;
847 			return NULL;
848 		}
849 
850 		wpa_printf(MSG_DEBUG, "SSL: Workaround - assume no Flags "
851 			   "indicates ACK frame");
852 		*flags = 0;
853 	} else {
854 		*flags = *pos++;
855 		left--;
856 	}
857 	wpa_printf(MSG_DEBUG, "SSL: Received packet(len=%lu) - "
858 		   "Flags 0x%02x", (unsigned long) wpabuf_len(reqData),
859 		   *flags);
860 	if (*flags & EAP_TLS_FLAGS_LENGTH_INCLUDED) {
861 		if (left < 4) {
862 			wpa_printf(MSG_INFO, "SSL: Short frame with TLS "
863 				   "length");
864 			ret->ignore = TRUE;
865 			return NULL;
866 		}
867 		tls_msg_len = WPA_GET_BE32(pos);
868 		wpa_printf(MSG_DEBUG, "SSL: TLS Message Length: %d",
869 			   tls_msg_len);
870 		if (data->tls_in_left == 0) {
871 			data->tls_in_total = tls_msg_len;
872 			data->tls_in_left = tls_msg_len;
873 			wpabuf_free(data->tls_in);
874 			data->tls_in = NULL;
875 		}
876 		pos += 4;
877 		left -= 4;
878 
879 		if (left > tls_msg_len) {
880 			wpa_printf(MSG_INFO, "SSL: TLS Message Length (%d "
881 				   "bytes) smaller than this fragment (%d "
882 				   "bytes)", (int) tls_msg_len, (int) left);
883 			ret->ignore = TRUE;
884 			return NULL;
885 		}
886 	}
887 
888 	ret->ignore = FALSE;
889 	ret->methodState = METHOD_MAY_CONT;
890 	ret->decision = DECISION_FAIL;
891 	ret->allowNotifications = TRUE;
892 
893 	*len = left;
894 	return pos;
895 }
896 
897 
898 /**
899  * eap_peer_tls_reset_input - Reset input buffers
900  * @data: Data for TLS processing
901  *
902  * This function frees any allocated memory for input buffers and resets input
903  * state.
904  */
eap_peer_tls_reset_input(struct eap_ssl_data * data)905 void eap_peer_tls_reset_input(struct eap_ssl_data *data)
906 {
907 	data->tls_in_left = data->tls_in_total = 0;
908 	wpabuf_free(data->tls_in);
909 	data->tls_in = NULL;
910 }
911 
912 
913 /**
914  * eap_peer_tls_reset_output - Reset output buffers
915  * @data: Data for TLS processing
916  *
917  * This function frees any allocated memory for output buffers and resets
918  * output state.
919  */
eap_peer_tls_reset_output(struct eap_ssl_data * data)920 void eap_peer_tls_reset_output(struct eap_ssl_data *data)
921 {
922 	data->tls_out_pos = 0;
923 	wpabuf_free(data->tls_out);
924 	data->tls_out = NULL;
925 }
926 
927 
928 /**
929  * eap_peer_tls_decrypt - Decrypt received phase 2 TLS message
930  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
931  * @data: Data for TLS processing
932  * @in_data: Message received from the server
933  * @in_decrypted: Buffer for returning a pointer to the decrypted message
934  * Returns: 0 on success, 1 if more input data is needed, or -1 on failure
935  */
eap_peer_tls_decrypt(struct eap_sm * sm,struct eap_ssl_data * data,const struct wpabuf * in_data,struct wpabuf ** in_decrypted)936 int eap_peer_tls_decrypt(struct eap_sm *sm, struct eap_ssl_data *data,
937 			 const struct wpabuf *in_data,
938 			 struct wpabuf **in_decrypted)
939 {
940 	const struct wpabuf *msg;
941 	int need_more_input;
942 
943 	msg = eap_peer_tls_data_reassemble(data, in_data, &need_more_input);
944 	if (msg == NULL)
945 		return need_more_input ? 1 : -1;
946 
947 	*in_decrypted = tls_connection_decrypt(data->ssl_ctx, data->conn, msg);
948 	eap_peer_tls_reset_input(data);
949 	if (*in_decrypted == NULL) {
950 		wpa_printf(MSG_INFO, "SSL: Failed to decrypt Phase 2 data");
951 		return -1;
952 	}
953 	return 0;
954 }
955 
956 
957 /**
958  * eap_peer_tls_encrypt - Encrypt phase 2 TLS message
959  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
960  * @data: Data for TLS processing
961  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
962  * @peap_version: Version number for EAP-PEAP/TTLS
963  * @id: EAP identifier for the response
964  * @in_data: Plaintext phase 2 data to encrypt or %NULL to continue fragments
965  * @out_data: Buffer for returning a pointer to the encrypted response message
966  * Returns: 0 on success, -1 on failure
967  */
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)968 int eap_peer_tls_encrypt(struct eap_sm *sm, struct eap_ssl_data *data,
969 			 EapType eap_type, int peap_version, u8 id,
970 			 const struct wpabuf *in_data,
971 			 struct wpabuf **out_data)
972 {
973 	if (in_data) {
974 		eap_peer_tls_reset_output(data);
975 		data->tls_out = tls_connection_encrypt(data->ssl_ctx,
976 						       data->conn, in_data);
977 		if (data->tls_out == NULL) {
978 			wpa_printf(MSG_INFO, "SSL: Failed to encrypt Phase 2 "
979 				   "data (in_len=%lu)",
980 				   (unsigned long) wpabuf_len(in_data));
981 			eap_peer_tls_reset_output(data);
982 			return -1;
983 		}
984 	}
985 
986 	return eap_tls_process_output(data, eap_type, peap_version, id, 0,
987 				      out_data);
988 }
989 
990 
991 /**
992  * eap_peer_select_phase2_methods - Select phase 2 EAP method
993  * @config: Pointer to the network configuration
994  * @prefix: 'phase2' configuration prefix, e.g., "auth="
995  * @types: Buffer for returning allocated list of allowed EAP methods
996  * @num_types: Buffer for returning number of allocated EAP methods
997  * Returns: 0 on success, -1 on failure
998  *
999  * This function is used to parse EAP method list and select allowed methods
1000  * for Phase2 authentication.
1001  */
eap_peer_select_phase2_methods(struct eap_peer_config * config,const char * prefix,struct eap_method_type ** types,size_t * num_types)1002 int eap_peer_select_phase2_methods(struct eap_peer_config *config,
1003 				   const char *prefix,
1004 				   struct eap_method_type **types,
1005 				   size_t *num_types)
1006 {
1007 	char *start, *pos, *buf;
1008 	struct eap_method_type *methods = NULL, *_methods;
1009 	u8 method;
1010 	size_t num_methods = 0, prefix_len;
1011 
1012 	if (config == NULL || config->phase2 == NULL)
1013 		goto get_defaults;
1014 
1015 	start = buf = os_strdup(config->phase2);
1016 	if (buf == NULL)
1017 		return -1;
1018 
1019 	prefix_len = os_strlen(prefix);
1020 
1021 	while (start && *start != '\0') {
1022 		int vendor;
1023 		pos = os_strstr(start, prefix);
1024 		if (pos == NULL)
1025 			break;
1026 		if (start != pos && *(pos - 1) != ' ') {
1027 			start = pos + prefix_len;
1028 			continue;
1029 		}
1030 
1031 		start = pos + prefix_len;
1032 		pos = os_strchr(start, ' ');
1033 		if (pos)
1034 			*pos++ = '\0';
1035 		method = eap_get_phase2_type(start, &vendor);
1036 		if (vendor == EAP_VENDOR_IETF && method == EAP_TYPE_NONE) {
1037 			wpa_printf(MSG_ERROR, "TLS: Unsupported Phase2 EAP "
1038 				   "method '%s'", start);
1039 		} else {
1040 			num_methods++;
1041 			_methods = os_realloc_array(methods, num_methods,
1042 						    sizeof(*methods));
1043 			if (_methods == NULL) {
1044 				os_free(methods);
1045 				os_free(buf);
1046 				return -1;
1047 			}
1048 			methods = _methods;
1049 			methods[num_methods - 1].vendor = vendor;
1050 			methods[num_methods - 1].method = method;
1051 		}
1052 
1053 		start = pos;
1054 	}
1055 
1056 	os_free(buf);
1057 
1058 get_defaults:
1059 	if (methods == NULL)
1060 		methods = eap_get_phase2_types(config, &num_methods);
1061 
1062 	if (methods == NULL) {
1063 		wpa_printf(MSG_ERROR, "TLS: No Phase2 EAP methods available");
1064 		return -1;
1065 	}
1066 	wpa_hexdump(MSG_DEBUG, "TLS: Phase2 EAP types",
1067 		    (u8 *) methods,
1068 		    num_methods * sizeof(struct eap_method_type));
1069 
1070 	*types = methods;
1071 	*num_types = num_methods;
1072 
1073 	return 0;
1074 }
1075 
1076 
1077 /**
1078  * eap_peer_tls_phase2_nak - Generate EAP-Nak for Phase 2
1079  * @types: Buffer for returning allocated list of allowed EAP methods
1080  * @num_types: Buffer for returning number of allocated EAP methods
1081  * @hdr: EAP-Request header (and the following EAP type octet)
1082  * @resp: Buffer for returning the EAP-Nak message
1083  * Returns: 0 on success, -1 on failure
1084  */
eap_peer_tls_phase2_nak(struct eap_method_type * types,size_t num_types,struct eap_hdr * hdr,struct wpabuf ** resp)1085 int eap_peer_tls_phase2_nak(struct eap_method_type *types, size_t num_types,
1086 			    struct eap_hdr *hdr, struct wpabuf **resp)
1087 {
1088 	u8 *pos = (u8 *) (hdr + 1);
1089 	size_t i;
1090 
1091 	/* TODO: add support for expanded Nak */
1092 	wpa_printf(MSG_DEBUG, "TLS: Phase 2 Request: Nak type=%d", *pos);
1093 	wpa_hexdump(MSG_DEBUG, "TLS: Allowed Phase2 EAP types",
1094 		    (u8 *) types, num_types * sizeof(struct eap_method_type));
1095 	*resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_NAK, num_types,
1096 			      EAP_CODE_RESPONSE, hdr->identifier);
1097 	if (*resp == NULL)
1098 		return -1;
1099 
1100 	for (i = 0; i < num_types; i++) {
1101 		if (types[i].vendor == EAP_VENDOR_IETF &&
1102 		    types[i].method < 256)
1103 			wpabuf_put_u8(*resp, types[i].method);
1104 	}
1105 
1106 	eap_update_len(*resp);
1107 
1108 	return 0;
1109 }
1110