1 /*
2 * EAP peer: EAP-TLS/PEAP/TTLS/FAST common functions
3 * Copyright (c) 2004-2008, Jouni Malinen <j@w1.fi>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * Alternatively, this software may be distributed under the terms of BSD
10 * license.
11 *
12 * See README and COPYING for more details.
13 */
14
15 #include "includes.h"
16
17 #include "common.h"
18 #include "eap_i.h"
19 #include "eap_tls_common.h"
20 #include "eap_config.h"
21 #include "crypto/sha1.h"
22 #include "crypto/tls.h"
23
24
eap_tls_check_blob(struct eap_sm * sm,const char ** name,const u8 ** data,size_t * data_len)25 static int eap_tls_check_blob(struct eap_sm *sm, const char **name,
26 const u8 **data, size_t *data_len)
27 {
28 const struct wpa_config_blob *blob;
29
30 if (*name == NULL || os_strncmp(*name, "blob://", 7) != 0)
31 return 0;
32
33 blob = eap_get_config_blob(sm, *name + 7);
34 if (blob == NULL) {
35 wpa_printf(MSG_ERROR, "%s: Named configuration blob '%s' not "
36 "found", __func__, *name + 7);
37 return -1;
38 }
39
40 *name = NULL;
41 *data = blob->data;
42 *data_len = blob->len;
43
44 return 0;
45 }
46
47
eap_tls_params_flags(struct tls_connection_params * params,const char * txt)48 static void eap_tls_params_flags(struct tls_connection_params *params,
49 const char *txt)
50 {
51 if (txt == NULL)
52 return;
53 if (os_strstr(txt, "tls_allow_md5=1"))
54 params->flags |= TLS_CONN_ALLOW_SIGN_RSA_MD5;
55 if (os_strstr(txt, "tls_disable_time_checks=1"))
56 params->flags |= TLS_CONN_DISABLE_TIME_CHECKS;
57 }
58
59
eap_tls_params_from_conf1(struct tls_connection_params * params,struct eap_peer_config * config)60 static void eap_tls_params_from_conf1(struct tls_connection_params *params,
61 struct eap_peer_config *config)
62 {
63 params->ca_cert = (char *) config->ca_cert;
64 params->ca_path = (char *) config->ca_path;
65 params->client_cert = (char *) config->client_cert;
66 params->private_key = (char *) config->private_key;
67 params->private_key_passwd = (char *) config->private_key_passwd;
68 params->dh_file = (char *) config->dh_file;
69 params->subject_match = (char *) config->subject_match;
70 params->altsubject_match = (char *) config->altsubject_match;
71 params->engine = config->engine;
72 params->engine_id = config->engine_id;
73 params->pin = config->pin;
74 params->key_id = config->key_id;
75 params->cert_id = config->cert_id;
76 params->ca_cert_id = config->ca_cert_id;
77 eap_tls_params_flags(params, config->phase1);
78 }
79
80
eap_tls_params_from_conf2(struct tls_connection_params * params,struct eap_peer_config * config)81 static void eap_tls_params_from_conf2(struct tls_connection_params *params,
82 struct eap_peer_config *config)
83 {
84 params->ca_cert = (char *) config->ca_cert2;
85 params->ca_path = (char *) config->ca_path2;
86 params->client_cert = (char *) config->client_cert2;
87 params->private_key = (char *) config->private_key2;
88 params->private_key_passwd = (char *) config->private_key2_passwd;
89 params->dh_file = (char *) config->dh_file2;
90 params->subject_match = (char *) config->subject_match2;
91 params->altsubject_match = (char *) config->altsubject_match2;
92 params->engine = config->engine2;
93 params->engine_id = config->engine2_id;
94 params->pin = config->pin2;
95 params->key_id = config->key2_id;
96 params->cert_id = config->cert2_id;
97 params->ca_cert_id = config->ca_cert2_id;
98 eap_tls_params_flags(params, config->phase2);
99 }
100
101
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)102 static int eap_tls_params_from_conf(struct eap_sm *sm,
103 struct eap_ssl_data *data,
104 struct tls_connection_params *params,
105 struct eap_peer_config *config, int phase2)
106 {
107 os_memset(params, 0, sizeof(*params));
108 if (phase2) {
109 wpa_printf(MSG_DEBUG, "TLS: using phase2 config options");
110 eap_tls_params_from_conf2(params, config);
111 } else {
112 wpa_printf(MSG_DEBUG, "TLS: using phase1 config options");
113 eap_tls_params_from_conf1(params, config);
114 }
115 params->tls_ia = data->tls_ia;
116
117 /*
118 * Use blob data, if available. Otherwise, leave reference to external
119 * file as-is.
120 */
121 if (eap_tls_check_blob(sm, ¶ms->ca_cert, ¶ms->ca_cert_blob,
122 ¶ms->ca_cert_blob_len) ||
123 eap_tls_check_blob(sm, ¶ms->client_cert,
124 ¶ms->client_cert_blob,
125 ¶ms->client_cert_blob_len) ||
126 eap_tls_check_blob(sm, ¶ms->private_key,
127 ¶ms->private_key_blob,
128 ¶ms->private_key_blob_len) ||
129 eap_tls_check_blob(sm, ¶ms->dh_file, ¶ms->dh_blob,
130 ¶ms->dh_blob_len)) {
131 wpa_printf(MSG_INFO, "SSL: Failed to get configuration blobs");
132 return -1;
133 }
134
135 return 0;
136 }
137
138
eap_tls_init_connection(struct eap_sm * sm,struct eap_ssl_data * data,struct eap_peer_config * config,struct tls_connection_params * params)139 static int eap_tls_init_connection(struct eap_sm *sm,
140 struct eap_ssl_data *data,
141 struct eap_peer_config *config,
142 struct tls_connection_params *params)
143 {
144 int res;
145
146 data->conn = tls_connection_init(sm->ssl_ctx);
147 if (data->conn == NULL) {
148 wpa_printf(MSG_INFO, "SSL: Failed to initialize new TLS "
149 "connection");
150 return -1;
151 }
152
153 res = tls_connection_set_params(sm->ssl_ctx, data->conn, params);
154 if (res == TLS_SET_PARAMS_ENGINE_PRV_INIT_FAILED) {
155 /*
156 * At this point with the pkcs11 engine the PIN might be wrong.
157 * We reset the PIN in the configuration to be sure to not use
158 * it again and the calling function must request a new one.
159 */
160 os_free(config->pin);
161 config->pin = NULL;
162 } else if (res == TLS_SET_PARAMS_ENGINE_PRV_VERIFY_FAILED) {
163 wpa_printf(MSG_INFO, "TLS: Failed to load private key");
164 /*
165 * We do not know exactly but maybe the PIN was wrong,
166 * so ask for a new one.
167 */
168 os_free(config->pin);
169 config->pin = NULL;
170 eap_sm_request_pin(sm);
171 sm->ignore = TRUE;
172 return -1;
173 } else if (res) {
174 wpa_printf(MSG_INFO, "TLS: Failed to set TLS connection "
175 "parameters");
176 return -1;
177 }
178
179 return 0;
180 }
181
182
183 /**
184 * eap_peer_tls_ssl_init - Initialize shared TLS functionality
185 * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
186 * @data: Data for TLS processing
187 * @config: Pointer to the network configuration
188 * Returns: 0 on success, -1 on failure
189 *
190 * This function is used to initialize shared TLS functionality for EAP-TLS,
191 * EAP-PEAP, EAP-TTLS, and EAP-FAST.
192 */
eap_peer_tls_ssl_init(struct eap_sm * sm,struct eap_ssl_data * data,struct eap_peer_config * config)193 int eap_peer_tls_ssl_init(struct eap_sm *sm, struct eap_ssl_data *data,
194 struct eap_peer_config *config)
195 {
196 struct tls_connection_params params;
197
198 if (config == NULL)
199 return -1;
200
201 data->eap = sm;
202 data->phase2 = sm->init_phase2;
203 if (eap_tls_params_from_conf(sm, data, ¶ms, config, data->phase2) <
204 0)
205 return -1;
206
207 if (eap_tls_init_connection(sm, data, config, ¶ms) < 0)
208 return -1;
209
210 data->tls_out_limit = config->fragment_size;
211 if (data->phase2) {
212 /* Limit the fragment size in the inner TLS authentication
213 * since the outer authentication with EAP-PEAP does not yet
214 * support fragmentation */
215 if (data->tls_out_limit > 100)
216 data->tls_out_limit -= 100;
217 }
218
219 if (config->phase1 &&
220 os_strstr(config->phase1, "include_tls_length=1")) {
221 wpa_printf(MSG_DEBUG, "TLS: Include TLS Message Length in "
222 "unfragmented packets");
223 data->include_tls_length = 1;
224 }
225
226 return 0;
227 }
228
229
230 /**
231 * eap_peer_tls_ssl_deinit - Deinitialize shared TLS functionality
232 * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
233 * @data: Data for TLS processing
234 *
235 * This function deinitializes shared TLS functionality that was initialized
236 * with eap_peer_tls_ssl_init().
237 */
eap_peer_tls_ssl_deinit(struct eap_sm * sm,struct eap_ssl_data * data)238 void eap_peer_tls_ssl_deinit(struct eap_sm *sm, struct eap_ssl_data *data)
239 {
240 tls_connection_deinit(sm->ssl_ctx, data->conn);
241 eap_peer_tls_reset_input(data);
242 eap_peer_tls_reset_output(data);
243 }
244
245
246 /**
247 * eap_peer_tls_derive_key - Derive a key based on TLS session data
248 * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
249 * @data: Data for TLS processing
250 * @label: Label string for deriving the keys, e.g., "client EAP encryption"
251 * @len: Length of the key material to generate (usually 64 for MSK)
252 * Returns: Pointer to allocated key on success or %NULL on failure
253 *
254 * This function uses TLS-PRF to generate pseudo-random data based on the TLS
255 * session data (client/server random and master key). Each key type may use a
256 * different label to bind the key usage into the generated material.
257 *
258 * The caller is responsible for freeing the returned buffer.
259 */
eap_peer_tls_derive_key(struct eap_sm * sm,struct eap_ssl_data * data,const char * label,size_t len)260 u8 * eap_peer_tls_derive_key(struct eap_sm *sm, struct eap_ssl_data *data,
261 const char *label, size_t len)
262 {
263 struct tls_keys keys;
264 u8 *rnd = NULL, *out;
265
266 out = os_malloc(len);
267 if (out == NULL)
268 return NULL;
269
270 /* First, try to use TLS library function for PRF, if available. */
271 if (tls_connection_prf(sm->ssl_ctx, data->conn, label, 0, out, len) ==
272 0)
273 return out;
274
275 /*
276 * TLS library did not support key generation, so get the needed TLS
277 * session parameters and use an internal implementation of TLS PRF to
278 * derive the key.
279 */
280 if (tls_connection_get_keys(sm->ssl_ctx, data->conn, &keys))
281 goto fail;
282
283 if (keys.client_random == NULL || keys.server_random == NULL ||
284 keys.master_key == NULL)
285 goto fail;
286
287 rnd = os_malloc(keys.client_random_len + keys.server_random_len);
288 if (rnd == NULL)
289 goto fail;
290 os_memcpy(rnd, keys.client_random, keys.client_random_len);
291 os_memcpy(rnd + keys.client_random_len, keys.server_random,
292 keys.server_random_len);
293
294 if (tls_prf(keys.master_key, keys.master_key_len,
295 label, rnd, keys.client_random_len +
296 keys.server_random_len, out, len))
297 goto fail;
298
299 os_free(rnd);
300 return out;
301
302 fail:
303 os_free(out);
304 os_free(rnd);
305 return NULL;
306 }
307
308
309 /**
310 * eap_peer_tls_reassemble_fragment - Reassemble a received fragment
311 * @data: Data for TLS processing
312 * @in_data: Next incoming TLS segment
313 * @in_len: Length of in_data
314 * Returns: 0 on success, 1 if more data is needed for the full message, or
315 * -1 on error
316 */
eap_peer_tls_reassemble_fragment(struct eap_ssl_data * data,const u8 * in_data,size_t in_len)317 static int eap_peer_tls_reassemble_fragment(struct eap_ssl_data *data,
318 const u8 *in_data, size_t in_len)
319 {
320 u8 *buf;
321
322 if (data->tls_in_len + in_len == 0) {
323 /* No message data received?! */
324 wpa_printf(MSG_WARNING, "SSL: Invalid reassembly state: "
325 "tls_in_left=%lu tls_in_len=%lu in_len=%lu",
326 (unsigned long) data->tls_in_left,
327 (unsigned long) data->tls_in_len,
328 (unsigned long) in_len);
329 eap_peer_tls_reset_input(data);
330 return -1;
331 }
332
333 if (data->tls_in_len + in_len > 65536) {
334 /*
335 * Limit length to avoid rogue servers from causing large
336 * memory allocations.
337 */
338 wpa_printf(MSG_INFO, "SSL: Too long TLS fragment (size over "
339 "64 kB)");
340 eap_peer_tls_reset_input(data);
341 return -1;
342 }
343
344 if (in_len > data->tls_in_left) {
345 /* Sender is doing something odd - reject message */
346 wpa_printf(MSG_INFO, "SSL: more data than TLS message length "
347 "indicated");
348 eap_peer_tls_reset_input(data);
349 return -1;
350 }
351
352 buf = os_realloc(data->tls_in, data->tls_in_len + in_len);
353 if (buf == NULL) {
354 wpa_printf(MSG_INFO, "SSL: Could not allocate memory for TLS "
355 "data");
356 eap_peer_tls_reset_input(data);
357 return -1;
358 }
359 os_memcpy(buf + data->tls_in_len, in_data, in_len);
360 data->tls_in = buf;
361 data->tls_in_len += in_len;
362 data->tls_in_left -= in_len;
363
364 if (data->tls_in_left > 0) {
365 wpa_printf(MSG_DEBUG, "SSL: Need %lu bytes more input "
366 "data", (unsigned long) data->tls_in_left);
367 return 1;
368 }
369
370 return 0;
371 }
372
373
374 /**
375 * eap_peer_tls_data_reassemble - Reassemble TLS data
376 * @data: Data for TLS processing
377 * @in_data: Next incoming TLS segment
378 * @in_len: Length of in_data
379 * @out_len: Variable for returning length of the reassembled message
380 * @need_more_input: Variable for returning whether more input data is needed
381 * to reassemble this TLS packet
382 * Returns: Pointer to output data, %NULL on error or when more data is needed
383 * for the full message (in which case, *need_more_input is also set to 1).
384 *
385 * This function reassembles TLS fragments. Caller must not free the returned
386 * data buffer since an internal pointer to it is maintained.
387 */
eap_peer_tls_data_reassemble(struct eap_ssl_data * data,const u8 * in_data,size_t in_len,size_t * out_len,int * need_more_input)388 const u8 * eap_peer_tls_data_reassemble(
389 struct eap_ssl_data *data, const u8 *in_data, size_t in_len,
390 size_t *out_len, int *need_more_input)
391 {
392 *need_more_input = 0;
393
394 if (data->tls_in_left > in_len || data->tls_in) {
395 /* Message has fragments */
396 int res = eap_peer_tls_reassemble_fragment(data, in_data,
397 in_len);
398 if (res) {
399 if (res == 1)
400 *need_more_input = 1;
401 return NULL;
402 }
403
404 /* Message is now fully reassembled. */
405 } else {
406 /* No fragments in this message, so just make a copy of it. */
407 data->tls_in_left = 0;
408 data->tls_in = os_malloc(in_len ? in_len : 1);
409 if (data->tls_in == NULL)
410 return NULL;
411 os_memcpy(data->tls_in, in_data, in_len);
412 data->tls_in_len = in_len;
413 }
414
415 *out_len = data->tls_in_len;
416 return data->tls_in;
417 }
418
419
420 /**
421 * eap_tls_process_input - Process incoming TLS message
422 * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
423 * @data: Data for TLS processing
424 * @in_data: Message received from the server
425 * @in_len: Length of in_data
426 * @out_data: Buffer for returning a pointer to application data (if available)
427 * Returns: 0 on success, 1 if more input data is needed, 2 if application data
428 * is available, -1 on failure
429 */
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)430 static int eap_tls_process_input(struct eap_sm *sm, struct eap_ssl_data *data,
431 const u8 *in_data, size_t in_len,
432 struct wpabuf **out_data)
433 {
434 const u8 *msg;
435 size_t msg_len;
436 int need_more_input;
437 u8 *appl_data;
438 size_t appl_data_len;
439
440 msg = eap_peer_tls_data_reassemble(data, in_data, in_len,
441 &msg_len, &need_more_input);
442 if (msg == NULL)
443 return need_more_input ? 1 : -1;
444
445 /* Full TLS message reassembled - continue handshake processing */
446 if (data->tls_out) {
447 /* This should not happen.. */
448 wpa_printf(MSG_INFO, "SSL: eap_tls_process_input - pending "
449 "tls_out data even though tls_out_len = 0");
450 os_free(data->tls_out);
451 WPA_ASSERT(data->tls_out == NULL);
452 }
453 appl_data = NULL;
454 data->tls_out = tls_connection_handshake(sm->ssl_ctx, data->conn,
455 msg, msg_len,
456 &data->tls_out_len,
457 &appl_data, &appl_data_len);
458
459 eap_peer_tls_reset_input(data);
460
461 if (appl_data &&
462 tls_connection_established(sm->ssl_ctx, data->conn) &&
463 !tls_connection_get_failed(sm->ssl_ctx, data->conn)) {
464 wpa_hexdump_key(MSG_MSGDUMP, "SSL: Application data",
465 appl_data, appl_data_len);
466 *out_data = wpabuf_alloc_ext_data(appl_data, appl_data_len);
467 if (*out_data == NULL) {
468 os_free(appl_data);
469 return -1;
470 }
471 return 2;
472 }
473
474 os_free(appl_data);
475
476 return 0;
477 }
478
479
480 /**
481 * eap_tls_process_output - Process outgoing TLS message
482 * @data: Data for TLS processing
483 * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
484 * @peap_version: Version number for EAP-PEAP/TTLS
485 * @id: EAP identifier for the response
486 * @ret: Return value to use on success
487 * @out_data: Buffer for returning the allocated output buffer
488 * Returns: ret (0 or 1) on success, -1 on failure
489 */
eap_tls_process_output(struct eap_ssl_data * data,EapType eap_type,int peap_version,u8 id,int ret,struct wpabuf ** out_data)490 static int eap_tls_process_output(struct eap_ssl_data *data, EapType eap_type,
491 int peap_version, u8 id, int ret,
492 struct wpabuf **out_data)
493 {
494 size_t len;
495 u8 *flags;
496 int more_fragments, length_included;
497
498 len = data->tls_out_len - data->tls_out_pos;
499 wpa_printf(MSG_DEBUG, "SSL: %lu bytes left to be sent out (of total "
500 "%lu bytes)",
501 (unsigned long) len, (unsigned long) data->tls_out_len);
502
503 /*
504 * Limit outgoing message to the configured maximum size. Fragment
505 * message if needed.
506 */
507 if (len > data->tls_out_limit) {
508 more_fragments = 1;
509 len = data->tls_out_limit;
510 wpa_printf(MSG_DEBUG, "SSL: sending %lu bytes, more fragments "
511 "will follow", (unsigned long) len);
512 } else
513 more_fragments = 0;
514
515 length_included = data->tls_out_pos == 0 &&
516 (data->tls_out_len > data->tls_out_limit ||
517 data->include_tls_length);
518 if (!length_included &&
519 eap_type == EAP_TYPE_PEAP && peap_version == 0 &&
520 !tls_connection_established(data->eap->ssl_ctx, data->conn)) {
521 /*
522 * Windows Server 2008 NPS really wants to have the TLS Message
523 * length included in phase 0 even for unfragmented frames or
524 * it will get very confused with Compound MAC calculation and
525 * Outer TLVs.
526 */
527 length_included = 1;
528 }
529
530 *out_data = eap_msg_alloc(EAP_VENDOR_IETF, eap_type,
531 1 + length_included * 4 + len,
532 EAP_CODE_RESPONSE, id);
533 if (*out_data == NULL)
534 return -1;
535
536 flags = wpabuf_put(*out_data, 1);
537 *flags = peap_version;
538 if (more_fragments)
539 *flags |= EAP_TLS_FLAGS_MORE_FRAGMENTS;
540 if (length_included) {
541 *flags |= EAP_TLS_FLAGS_LENGTH_INCLUDED;
542 wpabuf_put_be32(*out_data, data->tls_out_len);
543 }
544
545 wpabuf_put_data(*out_data, &data->tls_out[data->tls_out_pos], len);
546 data->tls_out_pos += len;
547
548 if (!more_fragments)
549 eap_peer_tls_reset_output(data);
550
551 return ret;
552 }
553
554
555 /**
556 * eap_peer_tls_process_helper - Process TLS handshake message
557 * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
558 * @data: Data for TLS processing
559 * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
560 * @peap_version: Version number for EAP-PEAP/TTLS
561 * @id: EAP identifier for the response
562 * @in_data: Message received from the server
563 * @in_len: Length of in_data
564 * @out_data: Buffer for returning a pointer to the response message
565 * Returns: 0 on success, 1 if more input data is needed, 2 if application data
566 * is available, or -1 on failure
567 *
568 * This function can be used to process TLS handshake messages. It reassembles
569 * the received fragments and uses a TLS library to process the messages. The
570 * response data from the TLS library is fragmented to suitable output messages
571 * that the caller can send out.
572 *
573 * out_data is used to return the response message if the return value of this
574 * function is 0, 2, or -1. In case of failure, the message is likely a TLS
575 * alarm message. The caller is responsible for freeing the allocated buffer if
576 * *out_data is not %NULL.
577 *
578 * This function is called for each received TLS message during the TLS
579 * handshake after eap_peer_tls_process_init() call and possible processing of
580 * TLS Flags field. Once the handshake has been completed, i.e., when
581 * tls_connection_established() returns 1, EAP method specific decrypting of
582 * the tunneled data is used.
583 */
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)584 int eap_peer_tls_process_helper(struct eap_sm *sm, struct eap_ssl_data *data,
585 EapType eap_type, int peap_version,
586 u8 id, const u8 *in_data, size_t in_len,
587 struct wpabuf **out_data)
588 {
589 int ret = 0;
590
591 *out_data = NULL;
592
593 if (data->tls_out_len > 0 && in_len > 0) {
594 wpa_printf(MSG_DEBUG, "SSL: Received non-ACK when output "
595 "fragments are waiting to be sent out");
596 return -1;
597 }
598
599 if (data->tls_out_len == 0) {
600 /*
601 * No more data to send out - expect to receive more data from
602 * the AS.
603 */
604 int res = eap_tls_process_input(sm, data, in_data, in_len,
605 out_data);
606 if (res) {
607 /*
608 * Input processing failed (res = -1) or more data is
609 * needed (res = 1).
610 */
611 return res;
612 }
613
614 /*
615 * The incoming message has been reassembled and processed. The
616 * response was allocated into data->tls_out buffer.
617 */
618 }
619
620 if (data->tls_out == NULL) {
621 /*
622 * No outgoing fragments remaining from the previous message
623 * and no new message generated. This indicates an error in TLS
624 * processing.
625 */
626 eap_peer_tls_reset_output(data);
627 return -1;
628 }
629
630 if (tls_connection_get_failed(sm->ssl_ctx, data->conn)) {
631 /* TLS processing has failed - return error */
632 wpa_printf(MSG_DEBUG, "SSL: Failed - tls_out available to "
633 "report error");
634 ret = -1;
635 /* TODO: clean pin if engine used? */
636 }
637
638 if (data->tls_out_len == 0) {
639 /*
640 * TLS negotiation should now be complete since all other cases
641 * needing more data should have been caught above based on
642 * the TLS Message Length field.
643 */
644 wpa_printf(MSG_DEBUG, "SSL: No data to be sent out");
645 os_free(data->tls_out);
646 data->tls_out = NULL;
647 return 1;
648 }
649
650 /* Send the pending message (in fragments, if needed). */
651 return eap_tls_process_output(data, eap_type, peap_version, id, ret,
652 out_data);
653 }
654
655
656 /**
657 * eap_peer_tls_build_ack - Build a TLS ACK frame
658 * @id: EAP identifier for the response
659 * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
660 * @peap_version: Version number for EAP-PEAP/TTLS
661 * Returns: Pointer to the allocated ACK frame or %NULL on failure
662 */
eap_peer_tls_build_ack(u8 id,EapType eap_type,int peap_version)663 struct wpabuf * eap_peer_tls_build_ack(u8 id, EapType eap_type,
664 int peap_version)
665 {
666 struct wpabuf *resp;
667
668 resp = eap_msg_alloc(EAP_VENDOR_IETF, eap_type, 1, EAP_CODE_RESPONSE,
669 id);
670 if (resp == NULL)
671 return NULL;
672 wpa_printf(MSG_DEBUG, "SSL: Building ACK (type=%d id=%d ver=%d)",
673 (int) eap_type, id, peap_version);
674 wpabuf_put_u8(resp, peap_version); /* Flags */
675 return resp;
676 }
677
678
679 /**
680 * eap_peer_tls_reauth_init - Re-initialize shared TLS for session resumption
681 * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
682 * @data: Data for TLS processing
683 * Returns: 0 on success, -1 on failure
684 */
eap_peer_tls_reauth_init(struct eap_sm * sm,struct eap_ssl_data * data)685 int eap_peer_tls_reauth_init(struct eap_sm *sm, struct eap_ssl_data *data)
686 {
687 eap_peer_tls_reset_input(data);
688 eap_peer_tls_reset_output(data);
689 return tls_connection_shutdown(sm->ssl_ctx, data->conn);
690 }
691
692
693 /**
694 * eap_peer_tls_status - Get TLS status
695 * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
696 * @data: Data for TLS processing
697 * @buf: Buffer for status information
698 * @buflen: Maximum buffer length
699 * @verbose: Whether to include verbose status information
700 * Returns: Number of bytes written to buf.
701 */
eap_peer_tls_status(struct eap_sm * sm,struct eap_ssl_data * data,char * buf,size_t buflen,int verbose)702 int eap_peer_tls_status(struct eap_sm *sm, struct eap_ssl_data *data,
703 char *buf, size_t buflen, int verbose)
704 {
705 char name[128];
706 int len = 0, ret;
707
708 if (tls_get_cipher(sm->ssl_ctx, data->conn, name, sizeof(name)) == 0) {
709 ret = os_snprintf(buf + len, buflen - len,
710 "EAP TLS cipher=%s\n", name);
711 if (ret < 0 || (size_t) ret >= buflen - len)
712 return len;
713 len += ret;
714 }
715
716 return len;
717 }
718
719
720 /**
721 * eap_peer_tls_process_init - Initial validation/processing of EAP requests
722 * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
723 * @data: Data for TLS processing
724 * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
725 * @ret: Return values from EAP request validation and processing
726 * @reqData: EAP request to be processed (eapReqData)
727 * @len: Buffer for returning length of the remaining payload
728 * @flags: Buffer for returning TLS flags
729 * Returns: Pointer to payload after TLS flags and length or %NULL on failure
730 *
731 * This function validates the EAP header and processes the optional TLS
732 * Message Length field. If this is the first fragment of a TLS message, the
733 * TLS reassembly code is initialized to receive the indicated number of bytes.
734 *
735 * EAP-TLS, EAP-PEAP, EAP-TTLS, and EAP-FAST methods are expected to use this
736 * function as the first step in processing received messages. They will need
737 * to process the flags (apart from Message Length Included) that are returned
738 * through the flags pointer and the message payload that will be returned (and
739 * the length is returned through the len pointer). Return values (ret) are set
740 * for continuation of EAP method processing. The caller is responsible for
741 * setting these to indicate completion (either success or failure) based on
742 * the authentication result.
743 */
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)744 const u8 * eap_peer_tls_process_init(struct eap_sm *sm,
745 struct eap_ssl_data *data,
746 EapType eap_type,
747 struct eap_method_ret *ret,
748 const struct wpabuf *reqData,
749 size_t *len, u8 *flags)
750 {
751 const u8 *pos;
752 size_t left;
753 unsigned int tls_msg_len;
754
755 if (tls_get_errors(sm->ssl_ctx)) {
756 wpa_printf(MSG_INFO, "SSL: TLS errors detected");
757 ret->ignore = TRUE;
758 return NULL;
759 }
760
761 pos = eap_hdr_validate(EAP_VENDOR_IETF, eap_type, reqData, &left);
762 if (pos == NULL) {
763 ret->ignore = TRUE;
764 return NULL;
765 }
766 if (left == 0) {
767 wpa_printf(MSG_DEBUG, "SSL: Invalid TLS message: no Flags "
768 "octet included");
769 if (!sm->workaround) {
770 ret->ignore = TRUE;
771 return NULL;
772 }
773
774 wpa_printf(MSG_DEBUG, "SSL: Workaround - assume no Flags "
775 "indicates ACK frame");
776 *flags = 0;
777 } else {
778 *flags = *pos++;
779 left--;
780 }
781 wpa_printf(MSG_DEBUG, "SSL: Received packet(len=%lu) - "
782 "Flags 0x%02x", (unsigned long) wpabuf_len(reqData),
783 *flags);
784 if (*flags & EAP_TLS_FLAGS_LENGTH_INCLUDED) {
785 if (left < 4) {
786 wpa_printf(MSG_INFO, "SSL: Short frame with TLS "
787 "length");
788 ret->ignore = TRUE;
789 return NULL;
790 }
791 tls_msg_len = WPA_GET_BE32(pos);
792 wpa_printf(MSG_DEBUG, "SSL: TLS Message Length: %d",
793 tls_msg_len);
794 if (data->tls_in_left == 0) {
795 data->tls_in_total = tls_msg_len;
796 data->tls_in_left = tls_msg_len;
797 os_free(data->tls_in);
798 data->tls_in = NULL;
799 data->tls_in_len = 0;
800 }
801 pos += 4;
802 left -= 4;
803 }
804
805 ret->ignore = FALSE;
806 ret->methodState = METHOD_MAY_CONT;
807 ret->decision = DECISION_FAIL;
808 ret->allowNotifications = TRUE;
809
810 *len = left;
811 return pos;
812 }
813
814
815 /**
816 * eap_peer_tls_reset_input - Reset input buffers
817 * @data: Data for TLS processing
818 *
819 * This function frees any allocated memory for input buffers and resets input
820 * state.
821 */
eap_peer_tls_reset_input(struct eap_ssl_data * data)822 void eap_peer_tls_reset_input(struct eap_ssl_data *data)
823 {
824 data->tls_in_left = data->tls_in_total = data->tls_in_len = 0;
825 os_free(data->tls_in);
826 data->tls_in = NULL;
827 }
828
829
830 /**
831 * eap_peer_tls_reset_output - Reset output buffers
832 * @data: Data for TLS processing
833 *
834 * This function frees any allocated memory for output buffers and resets
835 * output state.
836 */
eap_peer_tls_reset_output(struct eap_ssl_data * data)837 void eap_peer_tls_reset_output(struct eap_ssl_data *data)
838 {
839 data->tls_out_len = 0;
840 data->tls_out_pos = 0;
841 os_free(data->tls_out);
842 data->tls_out = NULL;
843 }
844
845
846 /**
847 * eap_peer_tls_decrypt - Decrypt received phase 2 TLS message
848 * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
849 * @data: Data for TLS processing
850 * @in_data: Message received from the server
851 * @in_decrypted: Buffer for returning a pointer to the decrypted message
852 * Returns: 0 on success, 1 if more input data is needed, or -1 on failure
853 */
eap_peer_tls_decrypt(struct eap_sm * sm,struct eap_ssl_data * data,const struct wpabuf * in_data,struct wpabuf ** in_decrypted)854 int eap_peer_tls_decrypt(struct eap_sm *sm, struct eap_ssl_data *data,
855 const struct wpabuf *in_data,
856 struct wpabuf **in_decrypted)
857 {
858 int res;
859 const u8 *msg;
860 size_t msg_len, buf_len;
861 int need_more_input;
862
863 msg = eap_peer_tls_data_reassemble(data, wpabuf_head(in_data),
864 wpabuf_len(in_data), &msg_len,
865 &need_more_input);
866 if (msg == NULL)
867 return need_more_input ? 1 : -1;
868
869 buf_len = wpabuf_len(in_data);
870 if (data->tls_in_total > buf_len)
871 buf_len = data->tls_in_total;
872 /*
873 * Even though we try to disable TLS compression, it is possible that
874 * this cannot be done with all TLS libraries. Add extra buffer space
875 * to handle the possibility of the decrypted data being longer than
876 * input data.
877 */
878 buf_len += 500;
879 buf_len *= 3;
880 *in_decrypted = wpabuf_alloc(buf_len ? buf_len : 1);
881 if (*in_decrypted == NULL) {
882 eap_peer_tls_reset_input(data);
883 wpa_printf(MSG_WARNING, "SSL: Failed to allocate memory for "
884 "decryption");
885 return -1;
886 }
887
888 res = tls_connection_decrypt(sm->ssl_ctx, data->conn, msg, msg_len,
889 wpabuf_mhead(*in_decrypted), buf_len);
890 eap_peer_tls_reset_input(data);
891 if (res < 0) {
892 wpa_printf(MSG_INFO, "SSL: Failed to decrypt Phase 2 data");
893 return -1;
894 }
895 wpabuf_put(*in_decrypted, res);
896 return 0;
897 }
898
899
900 /**
901 * eap_peer_tls_encrypt - Encrypt phase 2 TLS message
902 * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
903 * @data: Data for TLS processing
904 * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
905 * @peap_version: Version number for EAP-PEAP/TTLS
906 * @id: EAP identifier for the response
907 * @in_data: Plaintext phase 2 data to encrypt or %NULL to continue fragments
908 * @out_data: Buffer for returning a pointer to the encrypted response message
909 * Returns: 0 on success, -1 on failure
910 */
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)911 int eap_peer_tls_encrypt(struct eap_sm *sm, struct eap_ssl_data *data,
912 EapType eap_type, int peap_version, u8 id,
913 const struct wpabuf *in_data,
914 struct wpabuf **out_data)
915 {
916 int res;
917 size_t len;
918
919 if (in_data) {
920 eap_peer_tls_reset_output(data);
921 len = wpabuf_len(in_data) + 300;
922 data->tls_out = os_malloc(len);
923 if (data->tls_out == NULL)
924 return -1;
925
926 res = tls_connection_encrypt(sm->ssl_ctx, data->conn,
927 wpabuf_head(in_data),
928 wpabuf_len(in_data),
929 data->tls_out, len);
930 if (res < 0) {
931 wpa_printf(MSG_INFO, "SSL: Failed to encrypt Phase 2 "
932 "data (in_len=%lu)",
933 (unsigned long) wpabuf_len(in_data));
934 eap_peer_tls_reset_output(data);
935 return -1;
936 }
937
938 data->tls_out_len = res;
939 }
940
941 return eap_tls_process_output(data, eap_type, peap_version, id, 0,
942 out_data);
943 }
944
945
946 /**
947 * eap_peer_select_phase2_methods - Select phase 2 EAP method
948 * @config: Pointer to the network configuration
949 * @prefix: 'phase2' configuration prefix, e.g., "auth="
950 * @types: Buffer for returning allocated list of allowed EAP methods
951 * @num_types: Buffer for returning number of allocated EAP methods
952 * Returns: 0 on success, -1 on failure
953 *
954 * This function is used to parse EAP method list and select allowed methods
955 * for Phase2 authentication.
956 */
eap_peer_select_phase2_methods(struct eap_peer_config * config,const char * prefix,struct eap_method_type ** types,size_t * num_types)957 int eap_peer_select_phase2_methods(struct eap_peer_config *config,
958 const char *prefix,
959 struct eap_method_type **types,
960 size_t *num_types)
961 {
962 char *start, *pos, *buf;
963 struct eap_method_type *methods = NULL, *_methods;
964 u8 method;
965 size_t num_methods = 0, prefix_len;
966
967 if (config == NULL || config->phase2 == NULL)
968 goto get_defaults;
969
970 start = buf = os_strdup(config->phase2);
971 if (buf == NULL)
972 return -1;
973
974 prefix_len = os_strlen(prefix);
975
976 while (start && *start != '\0') {
977 int vendor;
978 pos = os_strstr(start, prefix);
979 if (pos == NULL)
980 break;
981 if (start != pos && *(pos - 1) != ' ') {
982 start = pos + prefix_len;
983 continue;
984 }
985
986 start = pos + prefix_len;
987 pos = os_strchr(start, ' ');
988 if (pos)
989 *pos++ = '\0';
990 method = eap_get_phase2_type(start, &vendor);
991 if (vendor == EAP_VENDOR_IETF && method == EAP_TYPE_NONE) {
992 wpa_printf(MSG_ERROR, "TLS: Unsupported Phase2 EAP "
993 "method '%s'", start);
994 } else {
995 num_methods++;
996 _methods = os_realloc(methods,
997 num_methods * sizeof(*methods));
998 if (_methods == NULL) {
999 os_free(methods);
1000 os_free(buf);
1001 return -1;
1002 }
1003 methods = _methods;
1004 methods[num_methods - 1].vendor = vendor;
1005 methods[num_methods - 1].method = method;
1006 }
1007
1008 start = pos;
1009 }
1010
1011 os_free(buf);
1012
1013 get_defaults:
1014 if (methods == NULL)
1015 methods = eap_get_phase2_types(config, &num_methods);
1016
1017 if (methods == NULL) {
1018 wpa_printf(MSG_ERROR, "TLS: No Phase2 EAP methods available");
1019 return -1;
1020 }
1021 wpa_hexdump(MSG_DEBUG, "TLS: Phase2 EAP types",
1022 (u8 *) methods,
1023 num_methods * sizeof(struct eap_method_type));
1024
1025 *types = methods;
1026 *num_types = num_methods;
1027
1028 return 0;
1029 }
1030
1031
1032 /**
1033 * eap_peer_tls_phase2_nak - Generate EAP-Nak for Phase 2
1034 * @types: Buffer for returning allocated list of allowed EAP methods
1035 * @num_types: Buffer for returning number of allocated EAP methods
1036 * @hdr: EAP-Request header (and the following EAP type octet)
1037 * @resp: Buffer for returning the EAP-Nak message
1038 * Returns: 0 on success, -1 on failure
1039 */
eap_peer_tls_phase2_nak(struct eap_method_type * types,size_t num_types,struct eap_hdr * hdr,struct wpabuf ** resp)1040 int eap_peer_tls_phase2_nak(struct eap_method_type *types, size_t num_types,
1041 struct eap_hdr *hdr, struct wpabuf **resp)
1042 {
1043 u8 *pos = (u8 *) (hdr + 1);
1044 size_t i;
1045
1046 /* TODO: add support for expanded Nak */
1047 wpa_printf(MSG_DEBUG, "TLS: Phase 2 Request: Nak type=%d", *pos);
1048 wpa_hexdump(MSG_DEBUG, "TLS: Allowed Phase2 EAP types",
1049 (u8 *) types, num_types * sizeof(struct eap_method_type));
1050 *resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_NAK, num_types,
1051 EAP_CODE_RESPONSE, hdr->identifier);
1052 if (*resp == NULL)
1053 return -1;
1054
1055 for (i = 0; i < num_types; i++) {
1056 if (types[i].vendor == EAP_VENDOR_IETF &&
1057 types[i].method < 256)
1058 wpabuf_put_u8(*resp, types[i].method);
1059 }
1060
1061 eap_update_len(*resp);
1062
1063 return 0;
1064 }
1065