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 	if (os_strstr(txt, "tls_suiteb=1"))
88 		params->flags |= TLS_CONN_SUITEB;
89 	if (os_strstr(txt, "tls_suiteb=0"))
90 		params->flags &= ~TLS_CONN_SUITEB;
91 	if (os_strstr(txt, "tls_suiteb_no_ecdh=1"))
92 		params->flags |= TLS_CONN_SUITEB_NO_ECDH;
93 	if (os_strstr(txt, "tls_suiteb_no_ecdh=0"))
94 		params->flags &= ~TLS_CONN_SUITEB_NO_ECDH;
95 }
96 
97 
eap_tls_params_from_conf1(struct tls_connection_params * params,struct eap_peer_config * config)98 static void eap_tls_params_from_conf1(struct tls_connection_params *params,
99 				      struct eap_peer_config *config)
100 {
101 	params->ca_cert = (char *) config->ca_cert;
102 	params->ca_path = (char *) config->ca_path;
103 	params->client_cert = (char *) config->client_cert;
104 	params->private_key = (char *) config->private_key;
105 	params->private_key_passwd = (char *) config->private_key_passwd;
106 	params->dh_file = (char *) config->dh_file;
107 	params->subject_match = (char *) config->subject_match;
108 	params->altsubject_match = (char *) config->altsubject_match;
109 	params->suffix_match = config->domain_suffix_match;
110 	params->domain_match = config->domain_match;
111 	params->engine = config->engine;
112 	params->engine_id = config->engine_id;
113 	params->pin = config->pin;
114 	params->key_id = config->key_id;
115 	params->cert_id = config->cert_id;
116 	params->ca_cert_id = config->ca_cert_id;
117 	eap_tls_params_flags(params, config->phase1);
118 }
119 
120 
eap_tls_params_from_conf2(struct tls_connection_params * params,struct eap_peer_config * config)121 static void eap_tls_params_from_conf2(struct tls_connection_params *params,
122 				      struct eap_peer_config *config)
123 {
124 	params->ca_cert = (char *) config->ca_cert2;
125 	params->ca_path = (char *) config->ca_path2;
126 	params->client_cert = (char *) config->client_cert2;
127 	params->private_key = (char *) config->private_key2;
128 	params->private_key_passwd = (char *) config->private_key2_passwd;
129 	params->dh_file = (char *) config->dh_file2;
130 	params->subject_match = (char *) config->subject_match2;
131 	params->altsubject_match = (char *) config->altsubject_match2;
132 	params->suffix_match = config->domain_suffix_match2;
133 	params->domain_match = config->domain_match2;
134 	params->engine = config->engine2;
135 	params->engine_id = config->engine2_id;
136 	params->pin = config->pin2;
137 	params->key_id = config->key2_id;
138 	params->cert_id = config->cert2_id;
139 	params->ca_cert_id = config->ca_cert2_id;
140 	eap_tls_params_flags(params, config->phase2);
141 }
142 
143 
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)144 static int eap_tls_params_from_conf(struct eap_sm *sm,
145 				    struct eap_ssl_data *data,
146 				    struct tls_connection_params *params,
147 				    struct eap_peer_config *config, int phase2)
148 {
149 	os_memset(params, 0, sizeof(*params));
150 	if (sm->workaround && data->eap_type != EAP_TYPE_FAST) {
151 		/*
152 		 * Some deployed authentication servers seem to be unable to
153 		 * handle the TLS Session Ticket extension (they are supposed
154 		 * to ignore unrecognized TLS extensions, but end up rejecting
155 		 * the ClientHello instead). As a workaround, disable use of
156 		 * TLS Sesson Ticket extension for EAP-TLS, EAP-PEAP, and
157 		 * EAP-TTLS (EAP-FAST uses session ticket, so any server that
158 		 * supports EAP-FAST does not need this workaround).
159 		 */
160 		params->flags |= TLS_CONN_DISABLE_SESSION_TICKET;
161 	}
162 	if (phase2) {
163 		wpa_printf(MSG_DEBUG, "TLS: using phase2 config options");
164 		eap_tls_params_from_conf2(params, config);
165 	} else {
166 		wpa_printf(MSG_DEBUG, "TLS: using phase1 config options");
167 		eap_tls_params_from_conf1(params, config);
168 		if (data->eap_type == EAP_TYPE_FAST)
169 			params->flags |= TLS_CONN_EAP_FAST;
170 	}
171 
172 	/*
173 	 * Use blob data, if available. Otherwise, leave reference to external
174 	 * file as-is.
175 	 */
176 	if (eap_tls_check_blob(sm, &params->ca_cert, &params->ca_cert_blob,
177 			       &params->ca_cert_blob_len) ||
178 	    eap_tls_check_blob(sm, &params->client_cert,
179 			       &params->client_cert_blob,
180 			       &params->client_cert_blob_len) ||
181 	    eap_tls_check_blob(sm, &params->private_key,
182 			       &params->private_key_blob,
183 			       &params->private_key_blob_len) ||
184 	    eap_tls_check_blob(sm, &params->dh_file, &params->dh_blob,
185 			       &params->dh_blob_len)) {
186 		wpa_printf(MSG_INFO, "SSL: Failed to get configuration blobs");
187 		return -1;
188 	}
189 
190 	params->openssl_ciphers = config->openssl_ciphers;
191 
192 	sm->ext_cert_check = !!(params->flags & TLS_CONN_EXT_CERT_CHECK);
193 
194 	return 0;
195 }
196 
197 
eap_tls_init_connection(struct eap_sm * sm,struct eap_ssl_data * data,struct eap_peer_config * config,struct tls_connection_params * params)198 static int eap_tls_init_connection(struct eap_sm *sm,
199 				   struct eap_ssl_data *data,
200 				   struct eap_peer_config *config,
201 				   struct tls_connection_params *params)
202 {
203 	int res;
204 
205 	if (config->ocsp)
206 		params->flags |= TLS_CONN_REQUEST_OCSP;
207 	if (config->ocsp >= 2)
208 		params->flags |= TLS_CONN_REQUIRE_OCSP;
209 	if (config->ocsp == 3)
210 		params->flags |= TLS_CONN_REQUIRE_OCSP_ALL;
211 	data->conn = tls_connection_init(data->ssl_ctx);
212 	if (data->conn == NULL) {
213 		wpa_printf(MSG_INFO, "SSL: Failed to initialize new TLS "
214 			   "connection");
215 		return -1;
216 	}
217 
218 	res = tls_connection_set_params(data->ssl_ctx, data->conn, params);
219 	if (res == TLS_SET_PARAMS_ENGINE_PRV_BAD_PIN) {
220 		/*
221 		 * At this point with the pkcs11 engine the PIN is wrong. We
222 		 * reset the PIN in the configuration to be sure to not use it
223 		 * again and the calling function must request a new one.
224 		 */
225 		wpa_printf(MSG_INFO,
226 			   "TLS: Bad PIN provided, requesting a new one");
227 		os_free(config->pin);
228 		config->pin = NULL;
229 		eap_sm_request_pin(sm);
230 		sm->ignore = TRUE;
231 	} else if (res == TLS_SET_PARAMS_ENGINE_PRV_INIT_FAILED) {
232 		wpa_printf(MSG_INFO, "TLS: Failed to initialize engine");
233 	} else if (res == TLS_SET_PARAMS_ENGINE_PRV_VERIFY_FAILED) {
234 		wpa_printf(MSG_INFO, "TLS: Failed to load private key");
235 		sm->ignore = TRUE;
236 	}
237 	if (res) {
238 		wpa_printf(MSG_INFO, "TLS: Failed to set TLS connection "
239 			   "parameters");
240 		tls_connection_deinit(data->ssl_ctx, data->conn);
241 		data->conn = NULL;
242 		return -1;
243 	}
244 
245 	return 0;
246 }
247 
248 
249 /**
250  * eap_peer_tls_ssl_init - Initialize shared TLS functionality
251  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
252  * @data: Data for TLS processing
253  * @config: Pointer to the network configuration
254  * @eap_type: EAP method used in Phase 1 (EAP_TYPE_TLS/PEAP/TTLS/FAST)
255  * Returns: 0 on success, -1 on failure
256  *
257  * This function is used to initialize shared TLS functionality for EAP-TLS,
258  * EAP-PEAP, EAP-TTLS, and EAP-FAST.
259  */
eap_peer_tls_ssl_init(struct eap_sm * sm,struct eap_ssl_data * data,struct eap_peer_config * config,u8 eap_type)260 int eap_peer_tls_ssl_init(struct eap_sm *sm, struct eap_ssl_data *data,
261 			  struct eap_peer_config *config, u8 eap_type)
262 {
263 	struct tls_connection_params params;
264 
265 	if (config == NULL)
266 		return -1;
267 
268 	data->eap = sm;
269 	data->eap_type = eap_type;
270 	data->phase2 = sm->init_phase2;
271 	data->ssl_ctx = sm->init_phase2 && sm->ssl_ctx2 ? sm->ssl_ctx2 :
272 		sm->ssl_ctx;
273 	if (eap_tls_params_from_conf(sm, data, &params, config, data->phase2) <
274 	    0)
275 		return -1;
276 
277 	if (eap_tls_init_connection(sm, data, config, &params) < 0)
278 		return -1;
279 
280 	data->tls_out_limit = config->fragment_size;
281 	if (data->phase2) {
282 		/* Limit the fragment size in the inner TLS authentication
283 		 * since the outer authentication with EAP-PEAP does not yet
284 		 * support fragmentation */
285 		if (data->tls_out_limit > 100)
286 			data->tls_out_limit -= 100;
287 	}
288 
289 	if (config->phase1 &&
290 	    os_strstr(config->phase1, "include_tls_length=1")) {
291 		wpa_printf(MSG_DEBUG, "TLS: Include TLS Message Length in "
292 			   "unfragmented packets");
293 		data->include_tls_length = 1;
294 	}
295 
296 	return 0;
297 }
298 
299 
300 /**
301  * eap_peer_tls_ssl_deinit - Deinitialize shared TLS functionality
302  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
303  * @data: Data for TLS processing
304  *
305  * This function deinitializes shared TLS functionality that was initialized
306  * with eap_peer_tls_ssl_init().
307  */
eap_peer_tls_ssl_deinit(struct eap_sm * sm,struct eap_ssl_data * data)308 void eap_peer_tls_ssl_deinit(struct eap_sm *sm, struct eap_ssl_data *data)
309 {
310 	tls_connection_deinit(data->ssl_ctx, data->conn);
311 	eap_peer_tls_reset_input(data);
312 	eap_peer_tls_reset_output(data);
313 }
314 
315 
316 /**
317  * eap_peer_tls_derive_key - Derive a key based on TLS session data
318  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
319  * @data: Data for TLS processing
320  * @label: Label string for deriving the keys, e.g., "client EAP encryption"
321  * @len: Length of the key material to generate (usually 64 for MSK)
322  * Returns: Pointer to allocated key on success or %NULL on failure
323  *
324  * This function uses TLS-PRF to generate pseudo-random data based on the TLS
325  * session data (client/server random and master key). Each key type may use a
326  * different label to bind the key usage into the generated material.
327  *
328  * The caller is responsible for freeing the returned buffer.
329  */
eap_peer_tls_derive_key(struct eap_sm * sm,struct eap_ssl_data * data,const char * label,size_t len)330 u8 * eap_peer_tls_derive_key(struct eap_sm *sm, struct eap_ssl_data *data,
331 			     const char *label, size_t len)
332 {
333 	u8 *out;
334 
335 	out = os_malloc(len);
336 	if (out == NULL)
337 		return NULL;
338 
339 	if (tls_connection_export_key(data->ssl_ctx, data->conn, label, out,
340 				      len)) {
341 		os_free(out);
342 		return NULL;
343 	}
344 
345 	return out;
346 }
347 
348 
349 /**
350  * eap_peer_tls_derive_session_id - Derive a Session-Id based on TLS data
351  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
352  * @data: Data for TLS processing
353  * @eap_type: EAP method used in Phase 1 (EAP_TYPE_TLS/PEAP/TTLS/FAST)
354  * @len: Pointer to length of the session ID generated
355  * Returns: Pointer to allocated Session-Id on success or %NULL on failure
356  *
357  * This function derive the Session-Id based on the TLS session data
358  * (client/server random and method type).
359  *
360  * The caller is responsible for freeing the returned buffer.
361  */
eap_peer_tls_derive_session_id(struct eap_sm * sm,struct eap_ssl_data * data,u8 eap_type,size_t * len)362 u8 * eap_peer_tls_derive_session_id(struct eap_sm *sm,
363 				    struct eap_ssl_data *data, u8 eap_type,
364 				    size_t *len)
365 {
366 	struct tls_random keys;
367 	u8 *out;
368 
369 	if (tls_connection_get_random(sm->ssl_ctx, data->conn, &keys) ||
370 	    keys.client_random == NULL || keys.server_random == 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  * @out_data: Buffer for returning a pointer to application data (if available)
499  * Returns: 0 on success, 1 if more input data is needed, 2 if application data
500  * is available, -1 on failure
501  */
eap_tls_process_input(struct eap_sm * sm,struct eap_ssl_data * data,const struct wpabuf * in_data,struct wpabuf ** out_data)502 static int eap_tls_process_input(struct eap_sm *sm, struct eap_ssl_data *data,
503 				 const struct wpabuf *in_data,
504 				 struct wpabuf **out_data)
505 {
506 	const struct wpabuf *msg;
507 	int need_more_input;
508 	struct wpabuf *appl_data;
509 
510 	msg = eap_peer_tls_data_reassemble(data, in_data, &need_more_input);
511 	if (msg == NULL)
512 		return need_more_input ? 1 : -1;
513 
514 	/* Full TLS message reassembled - continue handshake processing */
515 	if (data->tls_out) {
516 		/* This should not happen.. */
517 		wpa_printf(MSG_INFO, "SSL: eap_tls_process_input - pending "
518 			   "tls_out data even though tls_out_len = 0");
519 		wpabuf_free(data->tls_out);
520 		WPA_ASSERT(data->tls_out == NULL);
521 	}
522 	appl_data = NULL;
523 	data->tls_out = tls_connection_handshake(data->ssl_ctx, data->conn,
524 						 msg, &appl_data);
525 
526 	eap_peer_tls_reset_input(data);
527 
528 	if (appl_data &&
529 	    tls_connection_established(data->ssl_ctx, data->conn) &&
530 	    !tls_connection_get_failed(data->ssl_ctx, data->conn)) {
531 		wpa_hexdump_buf_key(MSG_MSGDUMP, "SSL: Application data",
532 				    appl_data);
533 		*out_data = appl_data;
534 		return 2;
535 	}
536 
537 	wpabuf_free(appl_data);
538 
539 	return 0;
540 }
541 
542 
543 /**
544  * eap_tls_process_output - Process outgoing TLS message
545  * @data: Data for TLS processing
546  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
547  * @peap_version: Version number for EAP-PEAP/TTLS
548  * @id: EAP identifier for the response
549  * @ret: Return value to use on success
550  * @out_data: Buffer for returning the allocated output buffer
551  * Returns: ret (0 or 1) on success, -1 on failure
552  */
eap_tls_process_output(struct eap_ssl_data * data,EapType eap_type,int peap_version,u8 id,int ret,struct wpabuf ** out_data)553 static int eap_tls_process_output(struct eap_ssl_data *data, EapType eap_type,
554 				  int peap_version, u8 id, int ret,
555 				  struct wpabuf **out_data)
556 {
557 	size_t len;
558 	u8 *flags;
559 	int more_fragments, length_included;
560 
561 	if (data->tls_out == NULL)
562 		return -1;
563 	len = wpabuf_len(data->tls_out) - data->tls_out_pos;
564 	wpa_printf(MSG_DEBUG, "SSL: %lu bytes left to be sent out (of total "
565 		   "%lu bytes)",
566 		   (unsigned long) len,
567 		   (unsigned long) wpabuf_len(data->tls_out));
568 
569 	/*
570 	 * Limit outgoing message to the configured maximum size. Fragment
571 	 * message if needed.
572 	 */
573 	if (len > data->tls_out_limit) {
574 		more_fragments = 1;
575 		len = data->tls_out_limit;
576 		wpa_printf(MSG_DEBUG, "SSL: sending %lu bytes, more fragments "
577 			   "will follow", (unsigned long) len);
578 	} else
579 		more_fragments = 0;
580 
581 	length_included = data->tls_out_pos == 0 &&
582 		(wpabuf_len(data->tls_out) > data->tls_out_limit ||
583 		 data->include_tls_length);
584 	if (!length_included &&
585 	    eap_type == EAP_TYPE_PEAP && peap_version == 0 &&
586 	    !tls_connection_established(data->eap->ssl_ctx, data->conn)) {
587 		/*
588 		 * Windows Server 2008 NPS really wants to have the TLS Message
589 		 * length included in phase 0 even for unfragmented frames or
590 		 * it will get very confused with Compound MAC calculation and
591 		 * Outer TLVs.
592 		 */
593 		length_included = 1;
594 	}
595 
596 	*out_data = eap_tls_msg_alloc(eap_type, 1 + length_included * 4 + len,
597 				      EAP_CODE_RESPONSE, id);
598 	if (*out_data == NULL)
599 		return -1;
600 
601 	flags = wpabuf_put(*out_data, 1);
602 	*flags = peap_version;
603 	if (more_fragments)
604 		*flags |= EAP_TLS_FLAGS_MORE_FRAGMENTS;
605 	if (length_included) {
606 		*flags |= EAP_TLS_FLAGS_LENGTH_INCLUDED;
607 		wpabuf_put_be32(*out_data, wpabuf_len(data->tls_out));
608 	}
609 
610 	wpabuf_put_data(*out_data,
611 			wpabuf_head_u8(data->tls_out) + data->tls_out_pos,
612 			len);
613 	data->tls_out_pos += len;
614 
615 	if (!more_fragments)
616 		eap_peer_tls_reset_output(data);
617 
618 	return ret;
619 }
620 
621 
622 /**
623  * eap_peer_tls_process_helper - Process TLS handshake message
624  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
625  * @data: Data for TLS processing
626  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
627  * @peap_version: Version number for EAP-PEAP/TTLS
628  * @id: EAP identifier for the response
629  * @in_data: Message received from the server
630  * @out_data: Buffer for returning a pointer to the response message
631  * Returns: 0 on success, 1 if more input data is needed, 2 if application data
632  * is available, or -1 on failure
633  *
634  * This function can be used to process TLS handshake messages. It reassembles
635  * the received fragments and uses a TLS library to process the messages. The
636  * response data from the TLS library is fragmented to suitable output messages
637  * that the caller can send out.
638  *
639  * out_data is used to return the response message if the return value of this
640  * function is 0, 2, or -1. In case of failure, the message is likely a TLS
641  * alarm message. The caller is responsible for freeing the allocated buffer if
642  * *out_data is not %NULL.
643  *
644  * This function is called for each received TLS message during the TLS
645  * handshake after eap_peer_tls_process_init() call and possible processing of
646  * TLS Flags field. Once the handshake has been completed, i.e., when
647  * tls_connection_established() returns 1, EAP method specific decrypting of
648  * the tunneled data is used.
649  */
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)650 int eap_peer_tls_process_helper(struct eap_sm *sm, struct eap_ssl_data *data,
651 				EapType eap_type, int peap_version,
652 				u8 id, const struct wpabuf *in_data,
653 				struct wpabuf **out_data)
654 {
655 	int ret = 0;
656 
657 	*out_data = NULL;
658 
659 	if (data->tls_out && wpabuf_len(data->tls_out) > 0 &&
660 	    wpabuf_len(in_data) > 0) {
661 		wpa_printf(MSG_DEBUG, "SSL: Received non-ACK when output "
662 			   "fragments are waiting to be sent out");
663 		return -1;
664 	}
665 
666 	if (data->tls_out == NULL || wpabuf_len(data->tls_out) == 0) {
667 		/*
668 		 * No more data to send out - expect to receive more data from
669 		 * the AS.
670 		 */
671 		int res = eap_tls_process_input(sm, data, in_data, out_data);
672 		if (res) {
673 			/*
674 			 * Input processing failed (res = -1) or more data is
675 			 * needed (res = 1).
676 			 */
677 			return res;
678 		}
679 
680 		/*
681 		 * The incoming message has been reassembled and processed. The
682 		 * response was allocated into data->tls_out buffer.
683 		 */
684 	}
685 
686 	if (data->tls_out == NULL) {
687 		/*
688 		 * No outgoing fragments remaining from the previous message
689 		 * and no new message generated. This indicates an error in TLS
690 		 * processing.
691 		 */
692 		eap_peer_tls_reset_output(data);
693 		return -1;
694 	}
695 
696 	if (tls_connection_get_failed(data->ssl_ctx, data->conn)) {
697 		/* TLS processing has failed - return error */
698 		wpa_printf(MSG_DEBUG, "SSL: Failed - tls_out available to "
699 			   "report error (len=%u)",
700 			   (unsigned int) wpabuf_len(data->tls_out));
701 		ret = -1;
702 		/* TODO: clean pin if engine used? */
703 		if (wpabuf_len(data->tls_out) == 0) {
704 			wpabuf_free(data->tls_out);
705 			data->tls_out = NULL;
706 			return -1;
707 		}
708 	}
709 
710 	if (wpabuf_len(data->tls_out) == 0) {
711 		/*
712 		 * TLS negotiation should now be complete since all other cases
713 		 * needing more data should have been caught above based on
714 		 * the TLS Message Length field.
715 		 */
716 		wpa_printf(MSG_DEBUG, "SSL: No data to be sent out");
717 		wpabuf_free(data->tls_out);
718 		data->tls_out = NULL;
719 		return 1;
720 	}
721 
722 	/* Send the pending message (in fragments, if needed). */
723 	return eap_tls_process_output(data, eap_type, peap_version, id, ret,
724 				      out_data);
725 }
726 
727 
728 /**
729  * eap_peer_tls_build_ack - Build a TLS ACK frame
730  * @id: EAP identifier for the response
731  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
732  * @peap_version: Version number for EAP-PEAP/TTLS
733  * Returns: Pointer to the allocated ACK frame or %NULL on failure
734  */
eap_peer_tls_build_ack(u8 id,EapType eap_type,int peap_version)735 struct wpabuf * eap_peer_tls_build_ack(u8 id, EapType eap_type,
736 				       int peap_version)
737 {
738 	struct wpabuf *resp;
739 
740 	resp = eap_tls_msg_alloc(eap_type, 1, EAP_CODE_RESPONSE, id);
741 	if (resp == NULL)
742 		return NULL;
743 	wpa_printf(MSG_DEBUG, "SSL: Building ACK (type=%d id=%d ver=%d)",
744 		   (int) eap_type, id, peap_version);
745 	wpabuf_put_u8(resp, peap_version); /* Flags */
746 	return resp;
747 }
748 
749 
750 /**
751  * eap_peer_tls_reauth_init - Re-initialize shared TLS for session resumption
752  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
753  * @data: Data for TLS processing
754  * Returns: 0 on success, -1 on failure
755  */
eap_peer_tls_reauth_init(struct eap_sm * sm,struct eap_ssl_data * data)756 int eap_peer_tls_reauth_init(struct eap_sm *sm, struct eap_ssl_data *data)
757 {
758 	eap_peer_tls_reset_input(data);
759 	eap_peer_tls_reset_output(data);
760 	return tls_connection_shutdown(data->ssl_ctx, data->conn);
761 }
762 
763 
764 /**
765  * eap_peer_tls_status - Get TLS status
766  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
767  * @data: Data for TLS processing
768  * @buf: Buffer for status information
769  * @buflen: Maximum buffer length
770  * @verbose: Whether to include verbose status information
771  * Returns: Number of bytes written to buf.
772  */
eap_peer_tls_status(struct eap_sm * sm,struct eap_ssl_data * data,char * buf,size_t buflen,int verbose)773 int eap_peer_tls_status(struct eap_sm *sm, struct eap_ssl_data *data,
774 			char *buf, size_t buflen, int verbose)
775 {
776 	char version[20], name[128];
777 	int len = 0, ret;
778 
779 	if (tls_get_version(data->ssl_ctx, data->conn, version,
780 			    sizeof(version)) < 0)
781 		version[0] = '\0';
782 	if (tls_get_cipher(data->ssl_ctx, data->conn, name, sizeof(name)) < 0)
783 		name[0] = '\0';
784 
785 	ret = os_snprintf(buf + len, buflen - len,
786 			  "eap_tls_version=%s\n"
787 			  "EAP TLS cipher=%s\n"
788 			  "tls_session_reused=%d\n",
789 			  version, name,
790 			  tls_connection_resumed(data->ssl_ctx, data->conn));
791 	if (os_snprintf_error(buflen - len, ret))
792 		return len;
793 	len += ret;
794 
795 	return len;
796 }
797 
798 
799 /**
800  * eap_peer_tls_process_init - Initial validation/processing of EAP requests
801  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
802  * @data: Data for TLS processing
803  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
804  * @ret: Return values from EAP request validation and processing
805  * @reqData: EAP request to be processed (eapReqData)
806  * @len: Buffer for returning length of the remaining payload
807  * @flags: Buffer for returning TLS flags
808  * Returns: Pointer to payload after TLS flags and length or %NULL on failure
809  *
810  * This function validates the EAP header and processes the optional TLS
811  * Message Length field. If this is the first fragment of a TLS message, the
812  * TLS reassembly code is initialized to receive the indicated number of bytes.
813  *
814  * EAP-TLS, EAP-PEAP, EAP-TTLS, and EAP-FAST methods are expected to use this
815  * function as the first step in processing received messages. They will need
816  * to process the flags (apart from Message Length Included) that are returned
817  * through the flags pointer and the message payload that will be returned (and
818  * the length is returned through the len pointer). Return values (ret) are set
819  * for continuation of EAP method processing. The caller is responsible for
820  * setting these to indicate completion (either success or failure) based on
821  * the authentication result.
822  */
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)823 const u8 * eap_peer_tls_process_init(struct eap_sm *sm,
824 				     struct eap_ssl_data *data,
825 				     EapType eap_type,
826 				     struct eap_method_ret *ret,
827 				     const struct wpabuf *reqData,
828 				     size_t *len, u8 *flags)
829 {
830 	const u8 *pos;
831 	size_t left;
832 	unsigned int tls_msg_len;
833 
834 	if (tls_get_errors(data->ssl_ctx)) {
835 		wpa_printf(MSG_INFO, "SSL: TLS errors detected");
836 		ret->ignore = TRUE;
837 		return NULL;
838 	}
839 
840 	if (eap_type == EAP_UNAUTH_TLS_TYPE)
841 		pos = eap_hdr_validate(EAP_VENDOR_UNAUTH_TLS,
842 				       EAP_VENDOR_TYPE_UNAUTH_TLS, reqData,
843 				       &left);
844 	else if (eap_type == EAP_WFA_UNAUTH_TLS_TYPE)
845 		pos = eap_hdr_validate(EAP_VENDOR_WFA_NEW,
846 				       EAP_VENDOR_WFA_UNAUTH_TLS, reqData,
847 				       &left);
848 	else
849 		pos = eap_hdr_validate(EAP_VENDOR_IETF, eap_type, reqData,
850 				       &left);
851 	if (pos == NULL) {
852 		ret->ignore = TRUE;
853 		return NULL;
854 	}
855 	if (left == 0) {
856 		wpa_printf(MSG_DEBUG, "SSL: Invalid TLS message: no Flags "
857 			   "octet included");
858 		if (!sm->workaround) {
859 			ret->ignore = TRUE;
860 			return NULL;
861 		}
862 
863 		wpa_printf(MSG_DEBUG, "SSL: Workaround - assume no Flags "
864 			   "indicates ACK frame");
865 		*flags = 0;
866 	} else {
867 		*flags = *pos++;
868 		left--;
869 	}
870 	wpa_printf(MSG_DEBUG, "SSL: Received packet(len=%lu) - "
871 		   "Flags 0x%02x", (unsigned long) wpabuf_len(reqData),
872 		   *flags);
873 	if (*flags & EAP_TLS_FLAGS_LENGTH_INCLUDED) {
874 		if (left < 4) {
875 			wpa_printf(MSG_INFO, "SSL: Short frame with TLS "
876 				   "length");
877 			ret->ignore = TRUE;
878 			return NULL;
879 		}
880 		tls_msg_len = WPA_GET_BE32(pos);
881 		wpa_printf(MSG_DEBUG, "SSL: TLS Message Length: %d",
882 			   tls_msg_len);
883 		if (data->tls_in_left == 0) {
884 			data->tls_in_total = tls_msg_len;
885 			data->tls_in_left = tls_msg_len;
886 			wpabuf_free(data->tls_in);
887 			data->tls_in = NULL;
888 		}
889 		pos += 4;
890 		left -= 4;
891 
892 		if (left > tls_msg_len) {
893 			wpa_printf(MSG_INFO, "SSL: TLS Message Length (%d "
894 				   "bytes) smaller than this fragment (%d "
895 				   "bytes)", (int) tls_msg_len, (int) left);
896 			ret->ignore = TRUE;
897 			return NULL;
898 		}
899 	}
900 
901 	ret->ignore = FALSE;
902 	ret->methodState = METHOD_MAY_CONT;
903 	ret->decision = DECISION_FAIL;
904 	ret->allowNotifications = TRUE;
905 
906 	*len = left;
907 	return pos;
908 }
909 
910 
911 /**
912  * eap_peer_tls_reset_input - Reset input buffers
913  * @data: Data for TLS processing
914  *
915  * This function frees any allocated memory for input buffers and resets input
916  * state.
917  */
eap_peer_tls_reset_input(struct eap_ssl_data * data)918 void eap_peer_tls_reset_input(struct eap_ssl_data *data)
919 {
920 	data->tls_in_left = data->tls_in_total = 0;
921 	wpabuf_free(data->tls_in);
922 	data->tls_in = NULL;
923 }
924 
925 
926 /**
927  * eap_peer_tls_reset_output - Reset output buffers
928  * @data: Data for TLS processing
929  *
930  * This function frees any allocated memory for output buffers and resets
931  * output state.
932  */
eap_peer_tls_reset_output(struct eap_ssl_data * data)933 void eap_peer_tls_reset_output(struct eap_ssl_data *data)
934 {
935 	data->tls_out_pos = 0;
936 	wpabuf_free(data->tls_out);
937 	data->tls_out = NULL;
938 }
939 
940 
941 /**
942  * eap_peer_tls_decrypt - Decrypt received phase 2 TLS message
943  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
944  * @data: Data for TLS processing
945  * @in_data: Message received from the server
946  * @in_decrypted: Buffer for returning a pointer to the decrypted message
947  * Returns: 0 on success, 1 if more input data is needed, or -1 on failure
948  */
eap_peer_tls_decrypt(struct eap_sm * sm,struct eap_ssl_data * data,const struct wpabuf * in_data,struct wpabuf ** in_decrypted)949 int eap_peer_tls_decrypt(struct eap_sm *sm, struct eap_ssl_data *data,
950 			 const struct wpabuf *in_data,
951 			 struct wpabuf **in_decrypted)
952 {
953 	const struct wpabuf *msg;
954 	int need_more_input;
955 
956 	msg = eap_peer_tls_data_reassemble(data, in_data, &need_more_input);
957 	if (msg == NULL)
958 		return need_more_input ? 1 : -1;
959 
960 	*in_decrypted = tls_connection_decrypt(data->ssl_ctx, data->conn, msg);
961 	eap_peer_tls_reset_input(data);
962 	if (*in_decrypted == NULL) {
963 		wpa_printf(MSG_INFO, "SSL: Failed to decrypt Phase 2 data");
964 		return -1;
965 	}
966 	return 0;
967 }
968 
969 
970 /**
971  * eap_peer_tls_encrypt - Encrypt phase 2 TLS message
972  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
973  * @data: Data for TLS processing
974  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
975  * @peap_version: Version number for EAP-PEAP/TTLS
976  * @id: EAP identifier for the response
977  * @in_data: Plaintext phase 2 data to encrypt or %NULL to continue fragments
978  * @out_data: Buffer for returning a pointer to the encrypted response message
979  * Returns: 0 on success, -1 on failure
980  */
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)981 int eap_peer_tls_encrypt(struct eap_sm *sm, struct eap_ssl_data *data,
982 			 EapType eap_type, int peap_version, u8 id,
983 			 const struct wpabuf *in_data,
984 			 struct wpabuf **out_data)
985 {
986 	if (in_data) {
987 		eap_peer_tls_reset_output(data);
988 		data->tls_out = tls_connection_encrypt(data->ssl_ctx,
989 						       data->conn, in_data);
990 		if (data->tls_out == NULL) {
991 			wpa_printf(MSG_INFO, "SSL: Failed to encrypt Phase 2 "
992 				   "data (in_len=%lu)",
993 				   (unsigned long) wpabuf_len(in_data));
994 			eap_peer_tls_reset_output(data);
995 			return -1;
996 		}
997 	}
998 
999 	return eap_tls_process_output(data, eap_type, peap_version, id, 0,
1000 				      out_data);
1001 }
1002 
1003 
1004 /**
1005  * eap_peer_select_phase2_methods - Select phase 2 EAP method
1006  * @config: Pointer to the network configuration
1007  * @prefix: 'phase2' configuration prefix, e.g., "auth="
1008  * @types: Buffer for returning allocated list of allowed EAP methods
1009  * @num_types: Buffer for returning number of allocated EAP methods
1010  * Returns: 0 on success, -1 on failure
1011  *
1012  * This function is used to parse EAP method list and select allowed methods
1013  * for Phase2 authentication.
1014  */
eap_peer_select_phase2_methods(struct eap_peer_config * config,const char * prefix,struct eap_method_type ** types,size_t * num_types)1015 int eap_peer_select_phase2_methods(struct eap_peer_config *config,
1016 				   const char *prefix,
1017 				   struct eap_method_type **types,
1018 				   size_t *num_types)
1019 {
1020 	char *start, *pos, *buf;
1021 	struct eap_method_type *methods = NULL, *_methods;
1022 	u32 method;
1023 	size_t num_methods = 0, prefix_len;
1024 
1025 	if (config == NULL || config->phase2 == NULL)
1026 		goto get_defaults;
1027 
1028 	start = buf = os_strdup(config->phase2);
1029 	if (buf == NULL)
1030 		return -1;
1031 
1032 	prefix_len = os_strlen(prefix);
1033 
1034 	while (start && *start != '\0') {
1035 		int vendor;
1036 		pos = os_strstr(start, prefix);
1037 		if (pos == NULL)
1038 			break;
1039 		if (start != pos && *(pos - 1) != ' ') {
1040 			start = pos + prefix_len;
1041 			continue;
1042 		}
1043 
1044 		start = pos + prefix_len;
1045 		pos = os_strchr(start, ' ');
1046 		if (pos)
1047 			*pos++ = '\0';
1048 		method = eap_get_phase2_type(start, &vendor);
1049 		if (vendor == EAP_VENDOR_IETF && method == EAP_TYPE_NONE) {
1050 			wpa_printf(MSG_ERROR, "TLS: Unsupported Phase2 EAP "
1051 				   "method '%s'", start);
1052 			os_free(methods);
1053 			os_free(buf);
1054 			return -1;
1055 		} else {
1056 			num_methods++;
1057 			_methods = os_realloc_array(methods, num_methods,
1058 						    sizeof(*methods));
1059 			if (_methods == NULL) {
1060 				os_free(methods);
1061 				os_free(buf);
1062 				return -1;
1063 			}
1064 			methods = _methods;
1065 			methods[num_methods - 1].vendor = vendor;
1066 			methods[num_methods - 1].method = method;
1067 		}
1068 
1069 		start = pos;
1070 	}
1071 
1072 	os_free(buf);
1073 
1074 get_defaults:
1075 	if (methods == NULL)
1076 		methods = eap_get_phase2_types(config, &num_methods);
1077 
1078 	if (methods == NULL) {
1079 		wpa_printf(MSG_ERROR, "TLS: No Phase2 EAP methods available");
1080 		return -1;
1081 	}
1082 	wpa_hexdump(MSG_DEBUG, "TLS: Phase2 EAP types",
1083 		    (u8 *) methods,
1084 		    num_methods * sizeof(struct eap_method_type));
1085 
1086 	*types = methods;
1087 	*num_types = num_methods;
1088 
1089 	return 0;
1090 }
1091 
1092 
1093 /**
1094  * eap_peer_tls_phase2_nak - Generate EAP-Nak for Phase 2
1095  * @types: Buffer for returning allocated list of allowed EAP methods
1096  * @num_types: Buffer for returning number of allocated EAP methods
1097  * @hdr: EAP-Request header (and the following EAP type octet)
1098  * @resp: Buffer for returning the EAP-Nak message
1099  * Returns: 0 on success, -1 on failure
1100  */
eap_peer_tls_phase2_nak(struct eap_method_type * types,size_t num_types,struct eap_hdr * hdr,struct wpabuf ** resp)1101 int eap_peer_tls_phase2_nak(struct eap_method_type *types, size_t num_types,
1102 			    struct eap_hdr *hdr, struct wpabuf **resp)
1103 {
1104 	u8 *pos = (u8 *) (hdr + 1);
1105 	size_t i;
1106 
1107 	/* TODO: add support for expanded Nak */
1108 	wpa_printf(MSG_DEBUG, "TLS: Phase 2 Request: Nak type=%d", *pos);
1109 	wpa_hexdump(MSG_DEBUG, "TLS: Allowed Phase2 EAP types",
1110 		    (u8 *) types, num_types * sizeof(struct eap_method_type));
1111 	*resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_NAK, num_types,
1112 			      EAP_CODE_RESPONSE, hdr->identifier);
1113 	if (*resp == NULL)
1114 		return -1;
1115 
1116 	for (i = 0; i < num_types; i++) {
1117 		if (types[i].vendor == EAP_VENDOR_IETF &&
1118 		    types[i].method < 256)
1119 			wpabuf_put_u8(*resp, types[i].method);
1120 	}
1121 
1122 	eap_update_len(*resp);
1123 
1124 	return 0;
1125 }
1126