xref: /freebsd/contrib/wpa/src/eap_peer/eap_tls_common.c (revision 7079fc4e0236ff334c2fb0f4367159be6df39332)
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 
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 
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 
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 
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 
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 
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 
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  */
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  */
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  */
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_reassemble_fragment - Reassemble a received fragment
344  * @data: Data for TLS processing
345  * @in_data: Next incoming TLS segment
346  * Returns: 0 on success, 1 if more data is needed for the full message, or
347  * -1 on error
348  */
349 static int eap_peer_tls_reassemble_fragment(struct eap_ssl_data *data,
350 					    const struct wpabuf *in_data)
351 {
352 	size_t tls_in_len, in_len;
353 
354 	tls_in_len = data->tls_in ? wpabuf_len(data->tls_in) : 0;
355 	in_len = in_data ? wpabuf_len(in_data) : 0;
356 
357 	if (tls_in_len + in_len == 0) {
358 		/* No message data received?! */
359 		wpa_printf(MSG_WARNING, "SSL: Invalid reassembly state: "
360 			   "tls_in_left=%lu tls_in_len=%lu in_len=%lu",
361 			   (unsigned long) data->tls_in_left,
362 			   (unsigned long) tls_in_len,
363 			   (unsigned long) in_len);
364 		eap_peer_tls_reset_input(data);
365 		return -1;
366 	}
367 
368 	if (tls_in_len + in_len > 65536) {
369 		/*
370 		 * Limit length to avoid rogue servers from causing large
371 		 * memory allocations.
372 		 */
373 		wpa_printf(MSG_INFO, "SSL: Too long TLS fragment (size over "
374 			   "64 kB)");
375 		eap_peer_tls_reset_input(data);
376 		return -1;
377 	}
378 
379 	if (in_len > data->tls_in_left) {
380 		/* Sender is doing something odd - reject message */
381 		wpa_printf(MSG_INFO, "SSL: more data than TLS message length "
382 			   "indicated");
383 		eap_peer_tls_reset_input(data);
384 		return -1;
385 	}
386 
387 	if (wpabuf_resize(&data->tls_in, in_len) < 0) {
388 		wpa_printf(MSG_INFO, "SSL: Could not allocate memory for TLS "
389 			   "data");
390 		eap_peer_tls_reset_input(data);
391 		return -1;
392 	}
393 	if (in_data)
394 		wpabuf_put_buf(data->tls_in, in_data);
395 	data->tls_in_left -= in_len;
396 
397 	if (data->tls_in_left > 0) {
398 		wpa_printf(MSG_DEBUG, "SSL: Need %lu bytes more input "
399 			   "data", (unsigned long) data->tls_in_left);
400 		return 1;
401 	}
402 
403 	return 0;
404 }
405 
406 
407 /**
408  * eap_peer_tls_data_reassemble - Reassemble TLS data
409  * @data: Data for TLS processing
410  * @in_data: Next incoming TLS segment
411  * @need_more_input: Variable for returning whether more input data is needed
412  * to reassemble this TLS packet
413  * Returns: Pointer to output data, %NULL on error or when more data is needed
414  * for the full message (in which case, *need_more_input is also set to 1).
415  *
416  * This function reassembles TLS fragments. Caller must not free the returned
417  * data buffer since an internal pointer to it is maintained.
418  */
419 static const struct wpabuf * eap_peer_tls_data_reassemble(
420 	struct eap_ssl_data *data, const struct wpabuf *in_data,
421 	int *need_more_input)
422 {
423 	*need_more_input = 0;
424 
425 	if (data->tls_in_left > wpabuf_len(in_data) || data->tls_in) {
426 		/* Message has fragments */
427 		int res = eap_peer_tls_reassemble_fragment(data, in_data);
428 		if (res) {
429 			if (res == 1)
430 				*need_more_input = 1;
431 			return NULL;
432 		}
433 
434 		/* Message is now fully reassembled. */
435 	} else {
436 		/* No fragments in this message, so just make a copy of it. */
437 		data->tls_in_left = 0;
438 		data->tls_in = wpabuf_dup(in_data);
439 		if (data->tls_in == NULL)
440 			return NULL;
441 	}
442 
443 	return data->tls_in;
444 }
445 
446 
447 /**
448  * eap_tls_process_input - Process incoming TLS message
449  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
450  * @data: Data for TLS processing
451  * @in_data: Message received from the server
452  * @in_len: Length of in_data
453  * @out_data: Buffer for returning a pointer to application data (if available)
454  * Returns: 0 on success, 1 if more input data is needed, 2 if application data
455  * is available, -1 on failure
456  */
457 static int eap_tls_process_input(struct eap_sm *sm, struct eap_ssl_data *data,
458 				 const u8 *in_data, size_t in_len,
459 				 struct wpabuf **out_data)
460 {
461 	const struct wpabuf *msg;
462 	int need_more_input;
463 	struct wpabuf *appl_data;
464 	struct wpabuf buf;
465 
466 	wpabuf_set(&buf, in_data, in_len);
467 	msg = eap_peer_tls_data_reassemble(data, &buf, &need_more_input);
468 	if (msg == NULL)
469 		return need_more_input ? 1 : -1;
470 
471 	/* Full TLS message reassembled - continue handshake processing */
472 	if (data->tls_out) {
473 		/* This should not happen.. */
474 		wpa_printf(MSG_INFO, "SSL: eap_tls_process_input - pending "
475 			   "tls_out data even though tls_out_len = 0");
476 		wpabuf_free(data->tls_out);
477 		WPA_ASSERT(data->tls_out == NULL);
478 	}
479 	appl_data = NULL;
480 	data->tls_out = tls_connection_handshake(data->ssl_ctx, data->conn,
481 						 msg, &appl_data);
482 
483 	eap_peer_tls_reset_input(data);
484 
485 	if (appl_data &&
486 	    tls_connection_established(data->ssl_ctx, data->conn) &&
487 	    !tls_connection_get_failed(data->ssl_ctx, data->conn)) {
488 		wpa_hexdump_buf_key(MSG_MSGDUMP, "SSL: Application data",
489 				    appl_data);
490 		*out_data = appl_data;
491 		return 2;
492 	}
493 
494 	wpabuf_free(appl_data);
495 
496 	return 0;
497 }
498 
499 
500 /**
501  * eap_tls_process_output - Process outgoing TLS message
502  * @data: Data for TLS processing
503  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
504  * @peap_version: Version number for EAP-PEAP/TTLS
505  * @id: EAP identifier for the response
506  * @ret: Return value to use on success
507  * @out_data: Buffer for returning the allocated output buffer
508  * Returns: ret (0 or 1) on success, -1 on failure
509  */
510 static int eap_tls_process_output(struct eap_ssl_data *data, EapType eap_type,
511 				  int peap_version, u8 id, int ret,
512 				  struct wpabuf **out_data)
513 {
514 	size_t len;
515 	u8 *flags;
516 	int more_fragments, length_included;
517 
518 	if (data->tls_out == NULL)
519 		return -1;
520 	len = wpabuf_len(data->tls_out) - data->tls_out_pos;
521 	wpa_printf(MSG_DEBUG, "SSL: %lu bytes left to be sent out (of total "
522 		   "%lu bytes)",
523 		   (unsigned long) len,
524 		   (unsigned long) wpabuf_len(data->tls_out));
525 
526 	/*
527 	 * Limit outgoing message to the configured maximum size. Fragment
528 	 * message if needed.
529 	 */
530 	if (len > data->tls_out_limit) {
531 		more_fragments = 1;
532 		len = data->tls_out_limit;
533 		wpa_printf(MSG_DEBUG, "SSL: sending %lu bytes, more fragments "
534 			   "will follow", (unsigned long) len);
535 	} else
536 		more_fragments = 0;
537 
538 	length_included = data->tls_out_pos == 0 &&
539 		(wpabuf_len(data->tls_out) > data->tls_out_limit ||
540 		 data->include_tls_length);
541 	if (!length_included &&
542 	    eap_type == EAP_TYPE_PEAP && peap_version == 0 &&
543 	    !tls_connection_established(data->eap->ssl_ctx, data->conn)) {
544 		/*
545 		 * Windows Server 2008 NPS really wants to have the TLS Message
546 		 * length included in phase 0 even for unfragmented frames or
547 		 * it will get very confused with Compound MAC calculation and
548 		 * Outer TLVs.
549 		 */
550 		length_included = 1;
551 	}
552 
553 	*out_data = eap_tls_msg_alloc(eap_type, 1 + length_included * 4 + len,
554 				      EAP_CODE_RESPONSE, id);
555 	if (*out_data == NULL)
556 		return -1;
557 
558 	flags = wpabuf_put(*out_data, 1);
559 	*flags = peap_version;
560 	if (more_fragments)
561 		*flags |= EAP_TLS_FLAGS_MORE_FRAGMENTS;
562 	if (length_included) {
563 		*flags |= EAP_TLS_FLAGS_LENGTH_INCLUDED;
564 		wpabuf_put_be32(*out_data, wpabuf_len(data->tls_out));
565 	}
566 
567 	wpabuf_put_data(*out_data,
568 			wpabuf_head_u8(data->tls_out) + data->tls_out_pos,
569 			len);
570 	data->tls_out_pos += len;
571 
572 	if (!more_fragments)
573 		eap_peer_tls_reset_output(data);
574 
575 	return ret;
576 }
577 
578 
579 /**
580  * eap_peer_tls_process_helper - Process TLS handshake message
581  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
582  * @data: Data for TLS processing
583  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
584  * @peap_version: Version number for EAP-PEAP/TTLS
585  * @id: EAP identifier for the response
586  * @in_data: Message received from the server
587  * @in_len: Length of in_data
588  * @out_data: Buffer for returning a pointer to the response message
589  * Returns: 0 on success, 1 if more input data is needed, 2 if application data
590  * is available, or -1 on failure
591  *
592  * This function can be used to process TLS handshake messages. It reassembles
593  * the received fragments and uses a TLS library to process the messages. The
594  * response data from the TLS library is fragmented to suitable output messages
595  * that the caller can send out.
596  *
597  * out_data is used to return the response message if the return value of this
598  * function is 0, 2, or -1. In case of failure, the message is likely a TLS
599  * alarm message. The caller is responsible for freeing the allocated buffer if
600  * *out_data is not %NULL.
601  *
602  * This function is called for each received TLS message during the TLS
603  * handshake after eap_peer_tls_process_init() call and possible processing of
604  * TLS Flags field. Once the handshake has been completed, i.e., when
605  * tls_connection_established() returns 1, EAP method specific decrypting of
606  * the tunneled data is used.
607  */
608 int eap_peer_tls_process_helper(struct eap_sm *sm, struct eap_ssl_data *data,
609 				EapType eap_type, int peap_version,
610 				u8 id, const u8 *in_data, size_t in_len,
611 				struct wpabuf **out_data)
612 {
613 	int ret = 0;
614 
615 	*out_data = NULL;
616 
617 	if (data->tls_out && wpabuf_len(data->tls_out) > 0 && in_len > 0) {
618 		wpa_printf(MSG_DEBUG, "SSL: Received non-ACK when output "
619 			   "fragments are waiting to be sent out");
620 		return -1;
621 	}
622 
623 	if (data->tls_out == NULL || wpabuf_len(data->tls_out) == 0) {
624 		/*
625 		 * No more data to send out - expect to receive more data from
626 		 * the AS.
627 		 */
628 		int res = eap_tls_process_input(sm, data, in_data, in_len,
629 						out_data);
630 		if (res) {
631 			/*
632 			 * Input processing failed (res = -1) or more data is
633 			 * needed (res = 1).
634 			 */
635 			return res;
636 		}
637 
638 		/*
639 		 * The incoming message has been reassembled and processed. The
640 		 * response was allocated into data->tls_out buffer.
641 		 */
642 	}
643 
644 	if (data->tls_out == NULL) {
645 		/*
646 		 * No outgoing fragments remaining from the previous message
647 		 * and no new message generated. This indicates an error in TLS
648 		 * processing.
649 		 */
650 		eap_peer_tls_reset_output(data);
651 		return -1;
652 	}
653 
654 	if (tls_connection_get_failed(data->ssl_ctx, data->conn)) {
655 		/* TLS processing has failed - return error */
656 		wpa_printf(MSG_DEBUG, "SSL: Failed - tls_out available to "
657 			   "report error");
658 		ret = -1;
659 		/* TODO: clean pin if engine used? */
660 	}
661 
662 	if (data->tls_out == NULL || wpabuf_len(data->tls_out) == 0) {
663 		/*
664 		 * TLS negotiation should now be complete since all other cases
665 		 * needing more data should have been caught above based on
666 		 * the TLS Message Length field.
667 		 */
668 		wpa_printf(MSG_DEBUG, "SSL: No data to be sent out");
669 		wpabuf_free(data->tls_out);
670 		data->tls_out = NULL;
671 		return 1;
672 	}
673 
674 	/* Send the pending message (in fragments, if needed). */
675 	return eap_tls_process_output(data, eap_type, peap_version, id, ret,
676 				      out_data);
677 }
678 
679 
680 /**
681  * eap_peer_tls_build_ack - Build a TLS ACK frame
682  * @id: EAP identifier for the response
683  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
684  * @peap_version: Version number for EAP-PEAP/TTLS
685  * Returns: Pointer to the allocated ACK frame or %NULL on failure
686  */
687 struct wpabuf * eap_peer_tls_build_ack(u8 id, EapType eap_type,
688 				       int peap_version)
689 {
690 	struct wpabuf *resp;
691 
692 	resp = eap_tls_msg_alloc(eap_type, 1, EAP_CODE_RESPONSE, id);
693 	if (resp == NULL)
694 		return NULL;
695 	wpa_printf(MSG_DEBUG, "SSL: Building ACK (type=%d id=%d ver=%d)",
696 		   (int) eap_type, id, peap_version);
697 	wpabuf_put_u8(resp, peap_version); /* Flags */
698 	return resp;
699 }
700 
701 
702 /**
703  * eap_peer_tls_reauth_init - Re-initialize shared TLS for session resumption
704  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
705  * @data: Data for TLS processing
706  * Returns: 0 on success, -1 on failure
707  */
708 int eap_peer_tls_reauth_init(struct eap_sm *sm, struct eap_ssl_data *data)
709 {
710 	eap_peer_tls_reset_input(data);
711 	eap_peer_tls_reset_output(data);
712 	return tls_connection_shutdown(data->ssl_ctx, data->conn);
713 }
714 
715 
716 /**
717  * eap_peer_tls_status - Get TLS status
718  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
719  * @data: Data for TLS processing
720  * @buf: Buffer for status information
721  * @buflen: Maximum buffer length
722  * @verbose: Whether to include verbose status information
723  * Returns: Number of bytes written to buf.
724  */
725 int eap_peer_tls_status(struct eap_sm *sm, struct eap_ssl_data *data,
726 			char *buf, size_t buflen, int verbose)
727 {
728 	char name[128];
729 	int len = 0, ret;
730 
731 	if (tls_get_cipher(data->ssl_ctx, data->conn, name, sizeof(name)) == 0)
732 	{
733 		ret = os_snprintf(buf + len, buflen - len,
734 				  "EAP TLS cipher=%s\n", name);
735 		if (ret < 0 || (size_t) ret >= buflen - len)
736 			return len;
737 		len += ret;
738 	}
739 
740 	return len;
741 }
742 
743 
744 /**
745  * eap_peer_tls_process_init - Initial validation/processing of EAP requests
746  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
747  * @data: Data for TLS processing
748  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
749  * @ret: Return values from EAP request validation and processing
750  * @reqData: EAP request to be processed (eapReqData)
751  * @len: Buffer for returning length of the remaining payload
752  * @flags: Buffer for returning TLS flags
753  * Returns: Pointer to payload after TLS flags and length or %NULL on failure
754  *
755  * This function validates the EAP header and processes the optional TLS
756  * Message Length field. If this is the first fragment of a TLS message, the
757  * TLS reassembly code is initialized to receive the indicated number of bytes.
758  *
759  * EAP-TLS, EAP-PEAP, EAP-TTLS, and EAP-FAST methods are expected to use this
760  * function as the first step in processing received messages. They will need
761  * to process the flags (apart from Message Length Included) that are returned
762  * through the flags pointer and the message payload that will be returned (and
763  * the length is returned through the len pointer). Return values (ret) are set
764  * for continuation of EAP method processing. The caller is responsible for
765  * setting these to indicate completion (either success or failure) based on
766  * the authentication result.
767  */
768 const u8 * eap_peer_tls_process_init(struct eap_sm *sm,
769 				     struct eap_ssl_data *data,
770 				     EapType eap_type,
771 				     struct eap_method_ret *ret,
772 				     const struct wpabuf *reqData,
773 				     size_t *len, u8 *flags)
774 {
775 	const u8 *pos;
776 	size_t left;
777 	unsigned int tls_msg_len;
778 
779 	if (tls_get_errors(data->ssl_ctx)) {
780 		wpa_printf(MSG_INFO, "SSL: TLS errors detected");
781 		ret->ignore = TRUE;
782 		return NULL;
783 	}
784 
785 	if (eap_type == EAP_UNAUTH_TLS_TYPE)
786 		pos = eap_hdr_validate(EAP_VENDOR_UNAUTH_TLS,
787 				       EAP_VENDOR_TYPE_UNAUTH_TLS, reqData,
788 				       &left);
789 	else
790 		pos = eap_hdr_validate(EAP_VENDOR_IETF, eap_type, reqData,
791 				       &left);
792 	if (pos == NULL) {
793 		ret->ignore = TRUE;
794 		return NULL;
795 	}
796 	if (left == 0) {
797 		wpa_printf(MSG_DEBUG, "SSL: Invalid TLS message: no Flags "
798 			   "octet included");
799 		if (!sm->workaround) {
800 			ret->ignore = TRUE;
801 			return NULL;
802 		}
803 
804 		wpa_printf(MSG_DEBUG, "SSL: Workaround - assume no Flags "
805 			   "indicates ACK frame");
806 		*flags = 0;
807 	} else {
808 		*flags = *pos++;
809 		left--;
810 	}
811 	wpa_printf(MSG_DEBUG, "SSL: Received packet(len=%lu) - "
812 		   "Flags 0x%02x", (unsigned long) wpabuf_len(reqData),
813 		   *flags);
814 	if (*flags & EAP_TLS_FLAGS_LENGTH_INCLUDED) {
815 		if (left < 4) {
816 			wpa_printf(MSG_INFO, "SSL: Short frame with TLS "
817 				   "length");
818 			ret->ignore = TRUE;
819 			return NULL;
820 		}
821 		tls_msg_len = WPA_GET_BE32(pos);
822 		wpa_printf(MSG_DEBUG, "SSL: TLS Message Length: %d",
823 			   tls_msg_len);
824 		if (data->tls_in_left == 0) {
825 			data->tls_in_total = tls_msg_len;
826 			data->tls_in_left = tls_msg_len;
827 			wpabuf_free(data->tls_in);
828 			data->tls_in = NULL;
829 		}
830 		pos += 4;
831 		left -= 4;
832 
833 		if (left > tls_msg_len) {
834 			wpa_printf(MSG_INFO, "SSL: TLS Message Length (%d "
835 				   "bytes) smaller than this fragment (%d "
836 				   "bytes)", (int) tls_msg_len, (int) left);
837 			ret->ignore = TRUE;
838 			return NULL;
839 		}
840 	}
841 
842 	ret->ignore = FALSE;
843 	ret->methodState = METHOD_MAY_CONT;
844 	ret->decision = DECISION_FAIL;
845 	ret->allowNotifications = TRUE;
846 
847 	*len = left;
848 	return pos;
849 }
850 
851 
852 /**
853  * eap_peer_tls_reset_input - Reset input buffers
854  * @data: Data for TLS processing
855  *
856  * This function frees any allocated memory for input buffers and resets input
857  * state.
858  */
859 void eap_peer_tls_reset_input(struct eap_ssl_data *data)
860 {
861 	data->tls_in_left = data->tls_in_total = 0;
862 	wpabuf_free(data->tls_in);
863 	data->tls_in = NULL;
864 }
865 
866 
867 /**
868  * eap_peer_tls_reset_output - Reset output buffers
869  * @data: Data for TLS processing
870  *
871  * This function frees any allocated memory for output buffers and resets
872  * output state.
873  */
874 void eap_peer_tls_reset_output(struct eap_ssl_data *data)
875 {
876 	data->tls_out_pos = 0;
877 	wpabuf_free(data->tls_out);
878 	data->tls_out = NULL;
879 }
880 
881 
882 /**
883  * eap_peer_tls_decrypt - Decrypt received phase 2 TLS message
884  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
885  * @data: Data for TLS processing
886  * @in_data: Message received from the server
887  * @in_decrypted: Buffer for returning a pointer to the decrypted message
888  * Returns: 0 on success, 1 if more input data is needed, or -1 on failure
889  */
890 int eap_peer_tls_decrypt(struct eap_sm *sm, struct eap_ssl_data *data,
891 			 const struct wpabuf *in_data,
892 			 struct wpabuf **in_decrypted)
893 {
894 	const struct wpabuf *msg;
895 	int need_more_input;
896 
897 	msg = eap_peer_tls_data_reassemble(data, in_data, &need_more_input);
898 	if (msg == NULL)
899 		return need_more_input ? 1 : -1;
900 
901 	*in_decrypted = tls_connection_decrypt(data->ssl_ctx, data->conn, msg);
902 	eap_peer_tls_reset_input(data);
903 	if (*in_decrypted == NULL) {
904 		wpa_printf(MSG_INFO, "SSL: Failed to decrypt Phase 2 data");
905 		return -1;
906 	}
907 	return 0;
908 }
909 
910 
911 /**
912  * eap_peer_tls_encrypt - Encrypt phase 2 TLS message
913  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
914  * @data: Data for TLS processing
915  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
916  * @peap_version: Version number for EAP-PEAP/TTLS
917  * @id: EAP identifier for the response
918  * @in_data: Plaintext phase 2 data to encrypt or %NULL to continue fragments
919  * @out_data: Buffer for returning a pointer to the encrypted response message
920  * Returns: 0 on success, -1 on failure
921  */
922 int eap_peer_tls_encrypt(struct eap_sm *sm, struct eap_ssl_data *data,
923 			 EapType eap_type, int peap_version, u8 id,
924 			 const struct wpabuf *in_data,
925 			 struct wpabuf **out_data)
926 {
927 	if (in_data) {
928 		eap_peer_tls_reset_output(data);
929 		data->tls_out = tls_connection_encrypt(data->ssl_ctx,
930 						       data->conn, in_data);
931 		if (data->tls_out == NULL) {
932 			wpa_printf(MSG_INFO, "SSL: Failed to encrypt Phase 2 "
933 				   "data (in_len=%lu)",
934 				   (unsigned long) wpabuf_len(in_data));
935 			eap_peer_tls_reset_output(data);
936 			return -1;
937 		}
938 	}
939 
940 	return eap_tls_process_output(data, eap_type, peap_version, id, 0,
941 				      out_data);
942 }
943 
944 
945 /**
946  * eap_peer_select_phase2_methods - Select phase 2 EAP method
947  * @config: Pointer to the network configuration
948  * @prefix: 'phase2' configuration prefix, e.g., "auth="
949  * @types: Buffer for returning allocated list of allowed EAP methods
950  * @num_types: Buffer for returning number of allocated EAP methods
951  * Returns: 0 on success, -1 on failure
952  *
953  * This function is used to parse EAP method list and select allowed methods
954  * for Phase2 authentication.
955  */
956 int eap_peer_select_phase2_methods(struct eap_peer_config *config,
957 				   const char *prefix,
958 				   struct eap_method_type **types,
959 				   size_t *num_types)
960 {
961 	char *start, *pos, *buf;
962 	struct eap_method_type *methods = NULL, *_methods;
963 	u8 method;
964 	size_t num_methods = 0, prefix_len;
965 
966 	if (config == NULL || config->phase2 == NULL)
967 		goto get_defaults;
968 
969 	start = buf = os_strdup(config->phase2);
970 	if (buf == NULL)
971 		return -1;
972 
973 	prefix_len = os_strlen(prefix);
974 
975 	while (start && *start != '\0') {
976 		int vendor;
977 		pos = os_strstr(start, prefix);
978 		if (pos == NULL)
979 			break;
980 		if (start != pos && *(pos - 1) != ' ') {
981 			start = pos + prefix_len;
982 			continue;
983 		}
984 
985 		start = pos + prefix_len;
986 		pos = os_strchr(start, ' ');
987 		if (pos)
988 			*pos++ = '\0';
989 		method = eap_get_phase2_type(start, &vendor);
990 		if (vendor == EAP_VENDOR_IETF && method == EAP_TYPE_NONE) {
991 			wpa_printf(MSG_ERROR, "TLS: Unsupported Phase2 EAP "
992 				   "method '%s'", start);
993 		} else {
994 			num_methods++;
995 			_methods = os_realloc_array(methods, num_methods,
996 						    sizeof(*methods));
997 			if (_methods == NULL) {
998 				os_free(methods);
999 				os_free(buf);
1000 				return -1;
1001 			}
1002 			methods = _methods;
1003 			methods[num_methods - 1].vendor = vendor;
1004 			methods[num_methods - 1].method = method;
1005 		}
1006 
1007 		start = pos;
1008 	}
1009 
1010 	os_free(buf);
1011 
1012 get_defaults:
1013 	if (methods == NULL)
1014 		methods = eap_get_phase2_types(config, &num_methods);
1015 
1016 	if (methods == NULL) {
1017 		wpa_printf(MSG_ERROR, "TLS: No Phase2 EAP methods available");
1018 		return -1;
1019 	}
1020 	wpa_hexdump(MSG_DEBUG, "TLS: Phase2 EAP types",
1021 		    (u8 *) methods,
1022 		    num_methods * sizeof(struct eap_method_type));
1023 
1024 	*types = methods;
1025 	*num_types = num_methods;
1026 
1027 	return 0;
1028 }
1029 
1030 
1031 /**
1032  * eap_peer_tls_phase2_nak - Generate EAP-Nak for Phase 2
1033  * @types: Buffer for returning allocated list of allowed EAP methods
1034  * @num_types: Buffer for returning number of allocated EAP methods
1035  * @hdr: EAP-Request header (and the following EAP type octet)
1036  * @resp: Buffer for returning the EAP-Nak message
1037  * Returns: 0 on success, -1 on failure
1038  */
1039 int eap_peer_tls_phase2_nak(struct eap_method_type *types, size_t num_types,
1040 			    struct eap_hdr *hdr, struct wpabuf **resp)
1041 {
1042 	u8 *pos = (u8 *) (hdr + 1);
1043 	size_t i;
1044 
1045 	/* TODO: add support for expanded Nak */
1046 	wpa_printf(MSG_DEBUG, "TLS: Phase 2 Request: Nak type=%d", *pos);
1047 	wpa_hexdump(MSG_DEBUG, "TLS: Allowed Phase2 EAP types",
1048 		    (u8 *) types, num_types * sizeof(struct eap_method_type));
1049 	*resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_NAK, num_types,
1050 			      EAP_CODE_RESPONSE, hdr->identifier);
1051 	if (*resp == NULL)
1052 		return -1;
1053 
1054 	for (i = 0; i < num_types; i++) {
1055 		if (types[i].vendor == EAP_VENDOR_IETF &&
1056 		    types[i].method < 256)
1057 			wpabuf_put_u8(*resp, types[i].method);
1058 	}
1059 
1060 	eap_update_len(*resp);
1061 
1062 	return 0;
1063 }
1064