xref: /freebsd/contrib/wpa/src/eap_server/eap_server_fast.c (revision a90b9d0159070121c221b966469c3e36d912bf82)
1 /*
2  * EAP-FAST server (RFC 4851)
3  * Copyright (c) 2004-2008, 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/aes_wrap.h"
13 #include "crypto/sha1.h"
14 #include "crypto/tls.h"
15 #include "crypto/random.h"
16 #include "eap_common/eap_tlv_common.h"
17 #include "eap_common/eap_fast_common.h"
18 #include "eap_i.h"
19 #include "eap_tls_common.h"
20 
21 
22 static void eap_fast_reset(struct eap_sm *sm, void *priv);
23 
24 
25 /* Private PAC-Opaque TLV types */
26 #define PAC_OPAQUE_TYPE_PAD 0
27 #define PAC_OPAQUE_TYPE_KEY 1
28 #define PAC_OPAQUE_TYPE_LIFETIME 2
29 #define PAC_OPAQUE_TYPE_IDENTITY 3
30 
31 struct eap_fast_data {
32 	struct eap_ssl_data ssl;
33 	enum {
34 		START, PHASE1, PHASE2_START, PHASE2_ID, PHASE2_METHOD,
35 		CRYPTO_BINDING, REQUEST_PAC, SUCCESS, FAILURE
36 	} state;
37 
38 	int fast_version;
39 	const struct eap_method *phase2_method;
40 	void *phase2_priv;
41 	int force_version;
42 	int peer_version;
43 
44 	u8 crypto_binding_nonce[32];
45 	int final_result;
46 
47 	struct eap_fast_key_block_provisioning *key_block_p;
48 
49 	u8 simck[EAP_FAST_SIMCK_LEN];
50 	u8 cmk[EAP_FAST_CMK_LEN];
51 	int simck_idx;
52 
53 	u8 pac_opaque_encr[16];
54 	u8 *srv_id;
55 	size_t srv_id_len;
56 	char *srv_id_info;
57 
58 	int anon_provisioning;
59 	int send_new_pac; /* server triggered re-keying of Tunnel PAC */
60 	struct wpabuf *pending_phase2_resp;
61 	u8 *identity; /* from PAC-Opaque */
62 	size_t identity_len;
63 	int eap_seq;
64 	int tnc_started;
65 
66 	int pac_key_lifetime;
67 	int pac_key_refresh_time;
68 };
69 
70 
71 static int eap_fast_process_phase2_start(struct eap_sm *sm,
72 					 struct eap_fast_data *data);
73 
74 
eap_fast_state_txt(int state)75 static const char * eap_fast_state_txt(int state)
76 {
77 	switch (state) {
78 	case START:
79 		return "START";
80 	case PHASE1:
81 		return "PHASE1";
82 	case PHASE2_START:
83 		return "PHASE2_START";
84 	case PHASE2_ID:
85 		return "PHASE2_ID";
86 	case PHASE2_METHOD:
87 		return "PHASE2_METHOD";
88 	case CRYPTO_BINDING:
89 		return "CRYPTO_BINDING";
90 	case REQUEST_PAC:
91 		return "REQUEST_PAC";
92 	case SUCCESS:
93 		return "SUCCESS";
94 	case FAILURE:
95 		return "FAILURE";
96 	default:
97 		return "Unknown?!";
98 	}
99 }
100 
101 
eap_fast_state(struct eap_fast_data * data,int state)102 static void eap_fast_state(struct eap_fast_data *data, int state)
103 {
104 	wpa_printf(MSG_DEBUG, "EAP-FAST: %s -> %s",
105 		   eap_fast_state_txt(data->state),
106 		   eap_fast_state_txt(state));
107 	data->state = state;
108 }
109 
110 
eap_fast_req_failure(struct eap_sm * sm,struct eap_fast_data * data)111 static enum eap_type eap_fast_req_failure(struct eap_sm *sm,
112 					  struct eap_fast_data *data)
113 {
114 	/* TODO: send Result TLV(FAILURE) */
115 	eap_fast_state(data, FAILURE);
116 	return EAP_TYPE_NONE;
117 }
118 
119 
eap_fast_session_ticket_cb(void * ctx,const u8 * ticket,size_t len,const u8 * client_random,const u8 * server_random,u8 * master_secret)120 static int eap_fast_session_ticket_cb(void *ctx, const u8 *ticket, size_t len,
121 				      const u8 *client_random,
122 				      const u8 *server_random,
123 				      u8 *master_secret)
124 {
125 	struct eap_fast_data *data = ctx;
126 	const u8 *pac_opaque;
127 	size_t pac_opaque_len;
128 	u8 *buf, *pos, *end, *pac_key = NULL;
129 	os_time_t lifetime = 0;
130 	struct os_time now;
131 	u8 *identity = NULL;
132 	size_t identity_len = 0;
133 
134 	wpa_printf(MSG_DEBUG, "EAP-FAST: SessionTicket callback");
135 	wpa_hexdump(MSG_DEBUG, "EAP-FAST: SessionTicket (PAC-Opaque)",
136 		    ticket, len);
137 
138 	if (len < 4 || WPA_GET_BE16(ticket) != PAC_TYPE_PAC_OPAQUE) {
139 		wpa_printf(MSG_DEBUG, "EAP-FAST: Ignore invalid "
140 			   "SessionTicket");
141 		return 0;
142 	}
143 
144 	pac_opaque_len = WPA_GET_BE16(ticket + 2);
145 	pac_opaque = ticket + 4;
146 	if (pac_opaque_len < 8 || pac_opaque_len % 8 ||
147 	    pac_opaque_len > len - 4) {
148 		wpa_printf(MSG_DEBUG, "EAP-FAST: Ignore invalid PAC-Opaque "
149 			   "(len=%lu left=%lu)",
150 			   (unsigned long) pac_opaque_len,
151 			   (unsigned long) len);
152 		return 0;
153 	}
154 	wpa_hexdump(MSG_DEBUG, "EAP-FAST: Received PAC-Opaque",
155 		    pac_opaque, pac_opaque_len);
156 
157 	buf = os_malloc(pac_opaque_len - 8);
158 	if (buf == NULL) {
159 		wpa_printf(MSG_DEBUG, "EAP-FAST: Failed to allocate memory "
160 			   "for decrypting PAC-Opaque");
161 		return 0;
162 	}
163 
164 	if (aes_unwrap(data->pac_opaque_encr, sizeof(data->pac_opaque_encr),
165 		       (pac_opaque_len - 8) / 8, pac_opaque, buf) < 0) {
166 		wpa_printf(MSG_DEBUG, "EAP-FAST: Failed to decrypt "
167 			   "PAC-Opaque");
168 		os_free(buf);
169 		/*
170 		 * This may have been caused by server changing the PAC-Opaque
171 		 * encryption key, so just ignore this PAC-Opaque instead of
172 		 * failing the authentication completely. Provisioning can now
173 		 * be used to provision a new PAC.
174 		 */
175 		return 0;
176 	}
177 
178 	end = buf + pac_opaque_len - 8;
179 	wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: Decrypted PAC-Opaque",
180 			buf, end - buf);
181 
182 	pos = buf;
183 	while (end - pos > 1) {
184 		u8 id, elen;
185 
186 		id = *pos++;
187 		elen = *pos++;
188 		if (elen > end - pos)
189 			break;
190 
191 		switch (id) {
192 		case PAC_OPAQUE_TYPE_PAD:
193 			goto done;
194 		case PAC_OPAQUE_TYPE_KEY:
195 			if (elen != EAP_FAST_PAC_KEY_LEN) {
196 				wpa_printf(MSG_DEBUG,
197 					   "EAP-FAST: Invalid PAC-Key length %d",
198 					   elen);
199 				os_free(buf);
200 				return -1;
201 			}
202 			pac_key = pos;
203 			wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: PAC-Key from "
204 					"decrypted PAC-Opaque",
205 					pac_key, EAP_FAST_PAC_KEY_LEN);
206 			break;
207 		case PAC_OPAQUE_TYPE_LIFETIME:
208 			if (elen != 4) {
209 				wpa_printf(MSG_DEBUG, "EAP-FAST: Invalid "
210 					   "PAC-Key lifetime length %d",
211 					   elen);
212 				os_free(buf);
213 				return -1;
214 			}
215 			lifetime = WPA_GET_BE32(pos);
216 			break;
217 		case PAC_OPAQUE_TYPE_IDENTITY:
218 			identity = pos;
219 			identity_len = elen;
220 			break;
221 		}
222 
223 		pos += elen;
224 	}
225 done:
226 
227 	if (pac_key == NULL) {
228 		wpa_printf(MSG_DEBUG, "EAP-FAST: No PAC-Key included in "
229 			   "PAC-Opaque");
230 		os_free(buf);
231 		return -1;
232 	}
233 
234 	if (identity) {
235 		wpa_hexdump_ascii(MSG_DEBUG, "EAP-FAST: Identity from "
236 				  "PAC-Opaque", identity, identity_len);
237 		os_free(data->identity);
238 		data->identity = os_malloc(identity_len);
239 		if (data->identity) {
240 			os_memcpy(data->identity, identity, identity_len);
241 			data->identity_len = identity_len;
242 		}
243 	}
244 
245 	if (os_get_time(&now) < 0 || lifetime <= 0 || now.sec > lifetime) {
246 		wpa_printf(MSG_DEBUG, "EAP-FAST: PAC-Key not valid anymore "
247 			   "(lifetime=%ld now=%ld)", lifetime, now.sec);
248 		data->send_new_pac = 2;
249 		/*
250 		 * Allow PAC to be used to allow a PAC update with some level
251 		 * of server authentication (i.e., do not fall back to full TLS
252 		 * handshake since we cannot be sure that the peer would be
253 		 * able to validate server certificate now). However, reject
254 		 * the authentication since the PAC was not valid anymore. Peer
255 		 * can connect again with the newly provisioned PAC after this.
256 		 */
257 	} else if (lifetime - now.sec < data->pac_key_refresh_time) {
258 		wpa_printf(MSG_DEBUG, "EAP-FAST: PAC-Key soft timeout; send "
259 			   "an update if authentication succeeds");
260 		data->send_new_pac = 1;
261 	}
262 
263 	eap_fast_derive_master_secret(pac_key, server_random, client_random,
264 				      master_secret);
265 
266 	os_free(buf);
267 
268 	return 1;
269 }
270 
271 
eap_fast_derive_key_auth(struct eap_sm * sm,struct eap_fast_data * data)272 static void eap_fast_derive_key_auth(struct eap_sm *sm,
273 				     struct eap_fast_data *data)
274 {
275 	u8 *sks;
276 
277 	/* RFC 4851, Section 5.1:
278 	 * Extra key material after TLS key_block: session_key_seed[40]
279 	 */
280 
281 	sks = eap_fast_derive_key(sm->cfg->ssl_ctx, data->ssl.conn,
282 				  EAP_FAST_SKS_LEN);
283 	if (sks == NULL) {
284 		wpa_printf(MSG_DEBUG, "EAP-FAST: Failed to derive "
285 			   "session_key_seed");
286 		return;
287 	}
288 
289 	/*
290 	 * RFC 4851, Section 5.2:
291 	 * S-IMCK[0] = session_key_seed
292 	 */
293 	wpa_hexdump_key(MSG_DEBUG,
294 			"EAP-FAST: session_key_seed (SKS = S-IMCK[0])",
295 			sks, EAP_FAST_SKS_LEN);
296 	data->simck_idx = 0;
297 	os_memcpy(data->simck, sks, EAP_FAST_SIMCK_LEN);
298 	os_free(sks);
299 }
300 
301 
eap_fast_derive_key_provisioning(struct eap_sm * sm,struct eap_fast_data * data)302 static void eap_fast_derive_key_provisioning(struct eap_sm *sm,
303 					     struct eap_fast_data *data)
304 {
305 	os_free(data->key_block_p);
306 	data->key_block_p = (struct eap_fast_key_block_provisioning *)
307 		eap_fast_derive_key(sm->cfg->ssl_ctx, data->ssl.conn,
308 				    sizeof(*data->key_block_p));
309 	if (data->key_block_p == NULL) {
310 		wpa_printf(MSG_DEBUG, "EAP-FAST: Failed to derive key block");
311 		return;
312 	}
313 	/*
314 	 * RFC 4851, Section 5.2:
315 	 * S-IMCK[0] = session_key_seed
316 	 */
317 	wpa_hexdump_key(MSG_DEBUG,
318 			"EAP-FAST: session_key_seed (SKS = S-IMCK[0])",
319 			data->key_block_p->session_key_seed,
320 			sizeof(data->key_block_p->session_key_seed));
321 	data->simck_idx = 0;
322 	os_memcpy(data->simck, data->key_block_p->session_key_seed,
323 		  EAP_FAST_SIMCK_LEN);
324 	wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: server_challenge",
325 			data->key_block_p->server_challenge,
326 			sizeof(data->key_block_p->server_challenge));
327 	wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: client_challenge",
328 			data->key_block_p->client_challenge,
329 			sizeof(data->key_block_p->client_challenge));
330 }
331 
332 
eap_fast_get_phase2_key(struct eap_sm * sm,struct eap_fast_data * data,u8 * isk,size_t isk_len)333 static int eap_fast_get_phase2_key(struct eap_sm *sm,
334 				   struct eap_fast_data *data,
335 				   u8 *isk, size_t isk_len)
336 {
337 	u8 *key;
338 	size_t key_len;
339 
340 	os_memset(isk, 0, isk_len);
341 
342 	if (data->phase2_method == NULL || data->phase2_priv == NULL) {
343 		wpa_printf(MSG_DEBUG, "EAP-FAST: Phase 2 method not "
344 			   "available");
345 		return -1;
346 	}
347 
348 	if (data->phase2_method->getKey == NULL)
349 		return 0;
350 
351 	if ((key = data->phase2_method->getKey(sm, data->phase2_priv,
352 					       &key_len)) == NULL) {
353 		wpa_printf(MSG_DEBUG, "EAP-FAST: Could not get key material "
354 			   "from Phase 2");
355 		return -1;
356 	}
357 
358 	if (key_len > isk_len)
359 		key_len = isk_len;
360 	os_memcpy(isk, key, key_len);
361 	os_free(key);
362 
363 	return 0;
364 }
365 
366 
eap_fast_update_icmk(struct eap_sm * sm,struct eap_fast_data * data)367 static int eap_fast_update_icmk(struct eap_sm *sm, struct eap_fast_data *data)
368 {
369 	u8 isk[32], imck[60];
370 
371 	wpa_printf(MSG_DEBUG, "EAP-FAST: Deriving ICMK[%d] (S-IMCK and CMK)",
372 		   data->simck_idx + 1);
373 
374 	/*
375 	 * RFC 4851, Section 5.2:
376 	 * IMCK[j] = T-PRF(S-IMCK[j-1], "Inner Methods Compound Keys",
377 	 *                 MSK[j], 60)
378 	 * S-IMCK[j] = first 40 octets of IMCK[j]
379 	 * CMK[j] = last 20 octets of IMCK[j]
380 	 */
381 
382 	if (eap_fast_get_phase2_key(sm, data, isk, sizeof(isk)) < 0)
383 		return -1;
384 	wpa_hexdump_key(MSG_MSGDUMP, "EAP-FAST: ISK[j]", isk, sizeof(isk));
385 	sha1_t_prf(data->simck, EAP_FAST_SIMCK_LEN,
386 		   "Inner Methods Compound Keys",
387 		   isk, sizeof(isk), imck, sizeof(imck));
388 	data->simck_idx++;
389 	os_memcpy(data->simck, imck, EAP_FAST_SIMCK_LEN);
390 	wpa_hexdump_key(MSG_MSGDUMP, "EAP-FAST: S-IMCK[j]",
391 			data->simck, EAP_FAST_SIMCK_LEN);
392 	os_memcpy(data->cmk, imck + EAP_FAST_SIMCK_LEN, EAP_FAST_CMK_LEN);
393 	wpa_hexdump_key(MSG_MSGDUMP, "EAP-FAST: CMK[j]",
394 			data->cmk, EAP_FAST_CMK_LEN);
395 
396 	return 0;
397 }
398 
399 
eap_fast_init(struct eap_sm * sm)400 static void * eap_fast_init(struct eap_sm *sm)
401 {
402 	struct eap_fast_data *data;
403 	u8 ciphers[7] = {
404 		TLS_CIPHER_ANON_DH_AES128_SHA,
405 		TLS_CIPHER_AES128_SHA,
406 		TLS_CIPHER_RSA_DHE_AES128_SHA,
407 		TLS_CIPHER_RC4_SHA,
408 		TLS_CIPHER_RSA_DHE_AES256_SHA,
409 		TLS_CIPHER_AES256_SHA,
410 		TLS_CIPHER_NONE
411 	};
412 
413 	data = os_zalloc(sizeof(*data));
414 	if (data == NULL)
415 		return NULL;
416 	data->fast_version = EAP_FAST_VERSION;
417 	data->force_version = -1;
418 	if (sm->user && sm->user->force_version >= 0) {
419 		data->force_version = sm->user->force_version;
420 		wpa_printf(MSG_DEBUG, "EAP-FAST: forcing version %d",
421 			   data->force_version);
422 		data->fast_version = data->force_version;
423 	}
424 	data->state = START;
425 
426 	if (eap_server_tls_ssl_init(sm, &data->ssl, 0, EAP_TYPE_FAST)) {
427 		wpa_printf(MSG_INFO, "EAP-FAST: Failed to initialize SSL.");
428 		eap_fast_reset(sm, data);
429 		return NULL;
430 	}
431 
432 	if (tls_connection_set_cipher_list(sm->cfg->ssl_ctx, data->ssl.conn,
433 					   ciphers) < 0) {
434 		wpa_printf(MSG_INFO, "EAP-FAST: Failed to set TLS cipher "
435 			   "suites");
436 		eap_fast_reset(sm, data);
437 		return NULL;
438 	}
439 
440 	if (tls_connection_set_session_ticket_cb(sm->cfg->ssl_ctx,
441 						 data->ssl.conn,
442 						 eap_fast_session_ticket_cb,
443 						 data) < 0) {
444 		wpa_printf(MSG_INFO, "EAP-FAST: Failed to set SessionTicket "
445 			   "callback");
446 		eap_fast_reset(sm, data);
447 		return NULL;
448 	}
449 
450 	if (sm->cfg->pac_opaque_encr_key == NULL) {
451 		wpa_printf(MSG_INFO, "EAP-FAST: No PAC-Opaque encryption key "
452 			   "configured");
453 		eap_fast_reset(sm, data);
454 		return NULL;
455 	}
456 	os_memcpy(data->pac_opaque_encr, sm->cfg->pac_opaque_encr_key,
457 		  sizeof(data->pac_opaque_encr));
458 
459 	if (sm->cfg->eap_fast_a_id == NULL) {
460 		wpa_printf(MSG_INFO, "EAP-FAST: No A-ID configured");
461 		eap_fast_reset(sm, data);
462 		return NULL;
463 	}
464 	data->srv_id = os_memdup(sm->cfg->eap_fast_a_id,
465 				 sm->cfg->eap_fast_a_id_len);
466 	if (data->srv_id == NULL) {
467 		eap_fast_reset(sm, data);
468 		return NULL;
469 	}
470 	data->srv_id_len = sm->cfg->eap_fast_a_id_len;
471 
472 	if (sm->cfg->eap_fast_a_id_info == NULL) {
473 		wpa_printf(MSG_INFO, "EAP-FAST: No A-ID-Info configured");
474 		eap_fast_reset(sm, data);
475 		return NULL;
476 	}
477 	data->srv_id_info = os_strdup(sm->cfg->eap_fast_a_id_info);
478 	if (data->srv_id_info == NULL) {
479 		eap_fast_reset(sm, data);
480 		return NULL;
481 	}
482 
483 	/* PAC-Key lifetime in seconds (hard limit) */
484 	data->pac_key_lifetime = sm->cfg->pac_key_lifetime;
485 
486 	/*
487 	 * PAC-Key refresh time in seconds (soft limit on remaining hard
488 	 * limit). The server will generate a new PAC-Key when this number of
489 	 * seconds (or fewer) of the lifetime remains.
490 	 */
491 	data->pac_key_refresh_time = sm->cfg->pac_key_refresh_time;
492 
493 	return data;
494 }
495 
496 
eap_fast_reset(struct eap_sm * sm,void * priv)497 static void eap_fast_reset(struct eap_sm *sm, void *priv)
498 {
499 	struct eap_fast_data *data = priv;
500 	if (data == NULL)
501 		return;
502 	if (data->phase2_priv && data->phase2_method)
503 		data->phase2_method->reset(sm, data->phase2_priv);
504 	eap_server_tls_ssl_deinit(sm, &data->ssl);
505 	os_free(data->srv_id);
506 	os_free(data->srv_id_info);
507 	os_free(data->key_block_p);
508 	wpabuf_free(data->pending_phase2_resp);
509 	os_free(data->identity);
510 	bin_clear_free(data, sizeof(*data));
511 }
512 
513 
eap_fast_build_start(struct eap_sm * sm,struct eap_fast_data * data,u8 id)514 static struct wpabuf * eap_fast_build_start(struct eap_sm *sm,
515 					    struct eap_fast_data *data, u8 id)
516 {
517 	struct wpabuf *req;
518 
519 	req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_FAST,
520 			    1 + sizeof(struct pac_tlv_hdr) + data->srv_id_len,
521 			    EAP_CODE_REQUEST, id);
522 	if (req == NULL) {
523 		wpa_printf(MSG_ERROR, "EAP-FAST: Failed to allocate memory for"
524 			   " request");
525 		eap_fast_state(data, FAILURE);
526 		return NULL;
527 	}
528 
529 	wpabuf_put_u8(req, EAP_TLS_FLAGS_START | data->fast_version);
530 
531 	/* RFC 4851, 4.1.1. Authority ID Data */
532 	eap_fast_put_tlv(req, PAC_TYPE_A_ID, data->srv_id, data->srv_id_len);
533 
534 	eap_fast_state(data, PHASE1);
535 
536 	return req;
537 }
538 
539 
eap_fast_phase1_done(struct eap_sm * sm,struct eap_fast_data * data)540 static int eap_fast_phase1_done(struct eap_sm *sm, struct eap_fast_data *data)
541 {
542 	char cipher[64];
543 
544 	wpa_printf(MSG_DEBUG, "EAP-FAST: Phase1 done, starting Phase2");
545 
546 	if (tls_get_cipher(sm->cfg->ssl_ctx, data->ssl.conn,
547 			   cipher, sizeof(cipher)) < 0) {
548 		wpa_printf(MSG_DEBUG, "EAP-FAST: Failed to get cipher "
549 			   "information");
550 		eap_fast_state(data, FAILURE);
551 		return -1;
552 	}
553 	data->anon_provisioning = os_strstr(cipher, "ADH") != NULL;
554 
555 	if (data->anon_provisioning) {
556 		wpa_printf(MSG_DEBUG, "EAP-FAST: Anonymous provisioning");
557 		eap_fast_derive_key_provisioning(sm, data);
558 	} else
559 		eap_fast_derive_key_auth(sm, data);
560 
561 	eap_fast_state(data, PHASE2_START);
562 
563 	return 0;
564 }
565 
566 
eap_fast_build_phase2_req(struct eap_sm * sm,struct eap_fast_data * data,u8 id)567 static struct wpabuf * eap_fast_build_phase2_req(struct eap_sm *sm,
568 						 struct eap_fast_data *data,
569 						 u8 id)
570 {
571 	struct wpabuf *req;
572 
573 	if (data->phase2_priv == NULL) {
574 		wpa_printf(MSG_DEBUG, "EAP-FAST: Phase 2 method not "
575 			   "initialized");
576 		return NULL;
577 	}
578 	req = data->phase2_method->buildReq(sm, data->phase2_priv, id);
579 	if (req == NULL)
580 		return NULL;
581 
582 	wpa_hexdump_buf_key(MSG_MSGDUMP, "EAP-FAST: Phase 2 EAP-Request", req);
583 	return eap_fast_tlv_eap_payload(req);
584 }
585 
586 
eap_fast_build_crypto_binding(struct eap_sm * sm,struct eap_fast_data * data)587 static struct wpabuf * eap_fast_build_crypto_binding(
588 	struct eap_sm *sm, struct eap_fast_data *data)
589 {
590 	struct wpabuf *buf;
591 	struct eap_tlv_result_tlv *result;
592 	struct eap_tlv_crypto_binding_tlv *binding;
593 
594 	buf = wpabuf_alloc(2 * sizeof(*result) + sizeof(*binding));
595 	if (buf == NULL)
596 		return NULL;
597 
598 	if (data->send_new_pac || data->anon_provisioning ||
599 	    data->phase2_method)
600 		data->final_result = 0;
601 	else
602 		data->final_result = 1;
603 
604 	if (!data->final_result || data->eap_seq > 1) {
605 		/* Intermediate-Result */
606 		wpa_printf(MSG_DEBUG, "EAP-FAST: Add Intermediate-Result TLV "
607 			   "(status=SUCCESS)");
608 		result = wpabuf_put(buf, sizeof(*result));
609 		result->tlv_type = host_to_be16(
610 			EAP_TLV_TYPE_MANDATORY |
611 			EAP_TLV_INTERMEDIATE_RESULT_TLV);
612 		result->length = host_to_be16(2);
613 		result->status = host_to_be16(EAP_TLV_RESULT_SUCCESS);
614 	}
615 
616 	if (data->final_result) {
617 		/* Result TLV */
618 		wpa_printf(MSG_DEBUG, "EAP-FAST: Add Result TLV "
619 			   "(status=SUCCESS)");
620 		result = wpabuf_put(buf, sizeof(*result));
621 		result->tlv_type = host_to_be16(EAP_TLV_TYPE_MANDATORY |
622 						EAP_TLV_RESULT_TLV);
623 		result->length = host_to_be16(2);
624 		result->status = host_to_be16(EAP_TLV_RESULT_SUCCESS);
625 	}
626 
627 	/* Crypto-Binding TLV */
628 	binding = wpabuf_put(buf, sizeof(*binding));
629 	binding->tlv_type = host_to_be16(EAP_TLV_TYPE_MANDATORY |
630 					 EAP_TLV_CRYPTO_BINDING_TLV);
631 	binding->length = host_to_be16(sizeof(*binding) -
632 				       sizeof(struct eap_tlv_hdr));
633 	binding->version = EAP_FAST_VERSION;
634 	binding->received_version = data->peer_version;
635 	binding->subtype = EAP_TLV_CRYPTO_BINDING_SUBTYPE_REQUEST;
636 	if (random_get_bytes(binding->nonce, sizeof(binding->nonce)) < 0) {
637 		wpabuf_free(buf);
638 		return NULL;
639 	}
640 
641 	/*
642 	 * RFC 4851, Section 4.2.8:
643 	 * The nonce in a request MUST have its least significant bit set to 0.
644 	 */
645 	binding->nonce[sizeof(binding->nonce) - 1] &= ~0x01;
646 
647 	os_memcpy(data->crypto_binding_nonce, binding->nonce,
648 		  sizeof(binding->nonce));
649 
650 	/*
651 	 * RFC 4851, Section 5.3:
652 	 * CMK = CMK[j]
653 	 * Compound-MAC = HMAC-SHA1( CMK, Crypto-Binding TLV )
654 	 */
655 
656 	hmac_sha1(data->cmk, EAP_FAST_CMK_LEN,
657 		  (u8 *) binding, sizeof(*binding),
658 		  binding->compound_mac);
659 
660 	wpa_printf(MSG_DEBUG, "EAP-FAST: Add Crypto-Binding TLV: Version %d "
661 		   "Received Version %d SubType %d",
662 		   binding->version, binding->received_version,
663 		   binding->subtype);
664 	wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: NONCE",
665 		    binding->nonce, sizeof(binding->nonce));
666 	wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: Compound MAC",
667 		    binding->compound_mac, sizeof(binding->compound_mac));
668 
669 	return buf;
670 }
671 
672 
eap_fast_build_pac(struct eap_sm * sm,struct eap_fast_data * data)673 static struct wpabuf * eap_fast_build_pac(struct eap_sm *sm,
674 					  struct eap_fast_data *data)
675 {
676 	u8 pac_key[EAP_FAST_PAC_KEY_LEN];
677 	u8 *pac_buf, *pac_opaque;
678 	struct wpabuf *buf;
679 	u8 *pos;
680 	size_t buf_len, srv_id_info_len, pac_len;
681 	struct eap_tlv_hdr *pac_tlv;
682 	struct pac_tlv_hdr *pac_info;
683 	struct eap_tlv_result_tlv *result;
684 	struct os_time now;
685 
686 	if (random_get_bytes(pac_key, EAP_FAST_PAC_KEY_LEN) < 0 ||
687 	    os_get_time(&now) < 0)
688 		return NULL;
689 	wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: Generated PAC-Key",
690 			pac_key, EAP_FAST_PAC_KEY_LEN);
691 
692 	pac_len = (2 + EAP_FAST_PAC_KEY_LEN) + (2 + 4) +
693 		(2 + sm->identity_len) + 8;
694 	pac_buf = os_malloc(pac_len);
695 	if (pac_buf == NULL)
696 		return NULL;
697 
698 	srv_id_info_len = os_strlen(data->srv_id_info);
699 
700 	pos = pac_buf;
701 	*pos++ = PAC_OPAQUE_TYPE_KEY;
702 	*pos++ = EAP_FAST_PAC_KEY_LEN;
703 	os_memcpy(pos, pac_key, EAP_FAST_PAC_KEY_LEN);
704 	pos += EAP_FAST_PAC_KEY_LEN;
705 
706 	*pos++ = PAC_OPAQUE_TYPE_LIFETIME;
707 	*pos++ = 4;
708 	WPA_PUT_BE32(pos, now.sec + data->pac_key_lifetime);
709 	pos += 4;
710 
711 	if (sm->identity) {
712 		*pos++ = PAC_OPAQUE_TYPE_IDENTITY;
713 		*pos++ = sm->identity_len;
714 		os_memcpy(pos, sm->identity, sm->identity_len);
715 		pos += sm->identity_len;
716 	}
717 
718 	pac_len = pos - pac_buf;
719 	while (pac_len % 8) {
720 		*pos++ = PAC_OPAQUE_TYPE_PAD;
721 		pac_len++;
722 	}
723 
724 	pac_opaque = os_malloc(pac_len + 8);
725 	if (pac_opaque == NULL) {
726 		os_free(pac_buf);
727 		return NULL;
728 	}
729 	if (aes_wrap(data->pac_opaque_encr, sizeof(data->pac_opaque_encr),
730 		     pac_len / 8, pac_buf, pac_opaque) < 0) {
731 		os_free(pac_buf);
732 		os_free(pac_opaque);
733 		return NULL;
734 	}
735 	os_free(pac_buf);
736 
737 	pac_len += 8;
738 	wpa_hexdump(MSG_DEBUG, "EAP-FAST: PAC-Opaque",
739 		    pac_opaque, pac_len);
740 
741 	buf_len = sizeof(*pac_tlv) +
742 		sizeof(struct pac_tlv_hdr) + EAP_FAST_PAC_KEY_LEN +
743 		sizeof(struct pac_tlv_hdr) + pac_len +
744 		data->srv_id_len + srv_id_info_len + 100 + sizeof(*result);
745 	buf = wpabuf_alloc(buf_len);
746 	if (buf == NULL) {
747 		os_free(pac_opaque);
748 		return NULL;
749 	}
750 
751 	/* Result TLV */
752 	wpa_printf(MSG_DEBUG, "EAP-FAST: Add Result TLV (status=SUCCESS)");
753 	result = wpabuf_put(buf, sizeof(*result));
754 	WPA_PUT_BE16((u8 *) &result->tlv_type,
755 		     EAP_TLV_TYPE_MANDATORY | EAP_TLV_RESULT_TLV);
756 	WPA_PUT_BE16((u8 *) &result->length, 2);
757 	WPA_PUT_BE16((u8 *) &result->status, EAP_TLV_RESULT_SUCCESS);
758 
759 	/* PAC TLV */
760 	wpa_printf(MSG_DEBUG, "EAP-FAST: Add PAC TLV");
761 	pac_tlv = wpabuf_put(buf, sizeof(*pac_tlv));
762 	pac_tlv->tlv_type = host_to_be16(EAP_TLV_TYPE_MANDATORY |
763 					 EAP_TLV_PAC_TLV);
764 
765 	/* PAC-Key */
766 	eap_fast_put_tlv(buf, PAC_TYPE_PAC_KEY, pac_key, EAP_FAST_PAC_KEY_LEN);
767 
768 	/* PAC-Opaque */
769 	eap_fast_put_tlv(buf, PAC_TYPE_PAC_OPAQUE, pac_opaque, pac_len);
770 	os_free(pac_opaque);
771 
772 	/* PAC-Info */
773 	pac_info = wpabuf_put(buf, sizeof(*pac_info));
774 	pac_info->type = host_to_be16(PAC_TYPE_PAC_INFO);
775 
776 	/* PAC-Lifetime (inside PAC-Info) */
777 	eap_fast_put_tlv_hdr(buf, PAC_TYPE_CRED_LIFETIME, 4);
778 	wpabuf_put_be32(buf, now.sec + data->pac_key_lifetime);
779 
780 	/* A-ID (inside PAC-Info) */
781 	eap_fast_put_tlv(buf, PAC_TYPE_A_ID, data->srv_id, data->srv_id_len);
782 
783 	/* Note: headers may be misaligned after A-ID */
784 
785 	if (sm->identity) {
786 		eap_fast_put_tlv(buf, PAC_TYPE_I_ID, sm->identity,
787 				 sm->identity_len);
788 	}
789 
790 	/* A-ID-Info (inside PAC-Info) */
791 	eap_fast_put_tlv(buf, PAC_TYPE_A_ID_INFO, data->srv_id_info,
792 			 srv_id_info_len);
793 
794 	/* PAC-Type (inside PAC-Info) */
795 	eap_fast_put_tlv_hdr(buf, PAC_TYPE_PAC_TYPE, 2);
796 	wpabuf_put_be16(buf, PAC_TYPE_TUNNEL_PAC);
797 
798 	/* Update PAC-Info and PAC TLV Length fields */
799 	pos = wpabuf_put(buf, 0);
800 	pac_info->len = host_to_be16(pos - (u8 *) (pac_info + 1));
801 	pac_tlv->length = host_to_be16(pos - (u8 *) (pac_tlv + 1));
802 
803 	return buf;
804 }
805 
806 
eap_fast_encrypt_phase2(struct eap_sm * sm,struct eap_fast_data * data,struct wpabuf * plain,int piggyback)807 static int eap_fast_encrypt_phase2(struct eap_sm *sm,
808 				   struct eap_fast_data *data,
809 				   struct wpabuf *plain, int piggyback)
810 {
811 	struct wpabuf *encr;
812 
813 	wpa_hexdump_buf_key(MSG_DEBUG, "EAP-FAST: Encrypting Phase 2 TLVs",
814 			    plain);
815 	encr = eap_server_tls_encrypt(sm, &data->ssl, plain);
816 	wpabuf_free(plain);
817 
818 	if (!encr)
819 		return -1;
820 
821 	if (data->ssl.tls_out && piggyback) {
822 		wpa_printf(MSG_DEBUG, "EAP-FAST: Piggyback Phase 2 data "
823 			   "(len=%d) with last Phase 1 Message (len=%d "
824 			   "used=%d)",
825 			   (int) wpabuf_len(encr),
826 			   (int) wpabuf_len(data->ssl.tls_out),
827 			   (int) data->ssl.tls_out_pos);
828 		if (wpabuf_resize(&data->ssl.tls_out, wpabuf_len(encr)) < 0) {
829 			wpa_printf(MSG_WARNING, "EAP-FAST: Failed to resize "
830 				   "output buffer");
831 			wpabuf_free(encr);
832 			return -1;
833 		}
834 		wpabuf_put_buf(data->ssl.tls_out, encr);
835 		wpabuf_free(encr);
836 	} else {
837 		wpabuf_free(data->ssl.tls_out);
838 		data->ssl.tls_out_pos = 0;
839 		data->ssl.tls_out = encr;
840 	}
841 
842 	return 0;
843 }
844 
845 
eap_fast_buildReq(struct eap_sm * sm,void * priv,u8 id)846 static struct wpabuf * eap_fast_buildReq(struct eap_sm *sm, void *priv, u8 id)
847 {
848 	struct eap_fast_data *data = priv;
849 	struct wpabuf *req = NULL;
850 	int piggyback = 0;
851 
852 	if (data->ssl.state == FRAG_ACK) {
853 		return eap_server_tls_build_ack(id, EAP_TYPE_FAST,
854 						data->fast_version);
855 	}
856 
857 	if (data->ssl.state == WAIT_FRAG_ACK) {
858 		return eap_server_tls_build_msg(&data->ssl, EAP_TYPE_FAST,
859 						data->fast_version, id);
860 	}
861 
862 	switch (data->state) {
863 	case START:
864 		return eap_fast_build_start(sm, data, id);
865 	case PHASE1:
866 		if (tls_connection_established(sm->cfg->ssl_ctx,
867 					       data->ssl.conn)) {
868 			if (eap_fast_phase1_done(sm, data) < 0)
869 				return NULL;
870 			if (data->state == PHASE2_START) {
871 				/*
872 				 * Try to generate Phase 2 data to piggyback
873 				 * with the end of Phase 1 to avoid extra
874 				 * roundtrip.
875 				 */
876 				wpa_printf(MSG_DEBUG, "EAP-FAST: Try to start "
877 					   "Phase 2");
878 				if (eap_fast_process_phase2_start(sm, data))
879 					break;
880 				req = eap_fast_build_phase2_req(sm, data, id);
881 				piggyback = 1;
882 			}
883 		}
884 		break;
885 	case PHASE2_ID:
886 	case PHASE2_METHOD:
887 		req = eap_fast_build_phase2_req(sm, data, id);
888 		break;
889 	case CRYPTO_BINDING:
890 		req = eap_fast_build_crypto_binding(sm, data);
891 		if (data->phase2_method) {
892 			/*
893 			 * Include the start of the next EAP method in the
894 			 * sequence in the same message with Crypto-Binding to
895 			 * save a round-trip.
896 			 */
897 			struct wpabuf *eap;
898 			eap = eap_fast_build_phase2_req(sm, data, id);
899 			req = wpabuf_concat(req, eap);
900 			eap_fast_state(data, PHASE2_METHOD);
901 		}
902 		break;
903 	case REQUEST_PAC:
904 		req = eap_fast_build_pac(sm, data);
905 		break;
906 	default:
907 		wpa_printf(MSG_DEBUG, "EAP-FAST: %s - unexpected state %d",
908 			   __func__, data->state);
909 		return NULL;
910 	}
911 
912 	if (req &&
913 	    eap_fast_encrypt_phase2(sm, data, req, piggyback) < 0)
914 		return NULL;
915 
916 	return eap_server_tls_build_msg(&data->ssl, EAP_TYPE_FAST,
917 					data->fast_version, id);
918 }
919 
920 
eap_fast_check(struct eap_sm * sm,void * priv,struct wpabuf * respData)921 static bool eap_fast_check(struct eap_sm *sm, void *priv,
922 			   struct wpabuf *respData)
923 {
924 	const u8 *pos;
925 	size_t len;
926 
927 	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_FAST, respData, &len);
928 	if (pos == NULL || len < 1) {
929 		wpa_printf(MSG_INFO, "EAP-FAST: Invalid frame");
930 		return true;
931 	}
932 
933 	return false;
934 }
935 
936 
eap_fast_phase2_init(struct eap_sm * sm,struct eap_fast_data * data,int vendor,enum eap_type eap_type)937 static int eap_fast_phase2_init(struct eap_sm *sm, struct eap_fast_data *data,
938 				int vendor, enum eap_type eap_type)
939 {
940 	if (data->phase2_priv && data->phase2_method) {
941 		data->phase2_method->reset(sm, data->phase2_priv);
942 		data->phase2_method = NULL;
943 		data->phase2_priv = NULL;
944 	}
945 	data->phase2_method = eap_server_get_eap_method(vendor, eap_type);
946 	if (!data->phase2_method)
947 		return -1;
948 
949 	if (data->key_block_p) {
950 		sm->auth_challenge = data->key_block_p->server_challenge;
951 		sm->peer_challenge = data->key_block_p->client_challenge;
952 	}
953 	sm->eap_fast_mschapv2 = true;
954 	sm->init_phase2 = 1;
955 	data->phase2_priv = data->phase2_method->init(sm);
956 	sm->init_phase2 = 0;
957 	sm->auth_challenge = NULL;
958 	sm->peer_challenge = NULL;
959 
960 	return data->phase2_priv == NULL ? -1 : 0;
961 }
962 
963 
eap_fast_process_phase2_response(struct eap_sm * sm,struct eap_fast_data * data,u8 * in_data,size_t in_len)964 static void eap_fast_process_phase2_response(struct eap_sm *sm,
965 					     struct eap_fast_data *data,
966 					     u8 *in_data, size_t in_len)
967 {
968 	int next_vendor = EAP_VENDOR_IETF;
969 	enum eap_type next_type = EAP_TYPE_NONE;
970 	struct eap_hdr *hdr;
971 	u8 *pos;
972 	size_t left;
973 	struct wpabuf buf;
974 	const struct eap_method *m = data->phase2_method;
975 	void *priv = data->phase2_priv;
976 
977 	if (priv == NULL) {
978 		wpa_printf(MSG_DEBUG, "EAP-FAST: %s - Phase2 not "
979 			   "initialized?!", __func__);
980 		return;
981 	}
982 
983 	hdr = (struct eap_hdr *) in_data;
984 	pos = (u8 *) (hdr + 1);
985 
986 	if (in_len > sizeof(*hdr) && *pos == EAP_TYPE_NAK) {
987 		left = in_len - sizeof(*hdr);
988 		wpa_hexdump(MSG_DEBUG, "EAP-FAST: Phase2 type Nak'ed; "
989 			    "allowed types", pos + 1, left - 1);
990 #ifdef EAP_SERVER_TNC
991 		if (m && m->vendor == EAP_VENDOR_IETF &&
992 		    m->method == EAP_TYPE_TNC) {
993 			wpa_printf(MSG_DEBUG, "EAP-FAST: Peer Nak'ed required "
994 				   "TNC negotiation");
995 			next_vendor = EAP_VENDOR_IETF;
996 			next_type = eap_fast_req_failure(sm, data);
997 			eap_fast_phase2_init(sm, data, next_vendor, next_type);
998 			return;
999 		}
1000 #endif /* EAP_SERVER_TNC */
1001 		eap_sm_process_nak(sm, pos + 1, left - 1);
1002 		if (sm->user && sm->user_eap_method_index < EAP_MAX_METHODS &&
1003 		    sm->user->methods[sm->user_eap_method_index].method !=
1004 		    EAP_TYPE_NONE) {
1005 			next_vendor = sm->user->methods[
1006 				sm->user_eap_method_index].vendor;
1007 			next_type = sm->user->methods[
1008 				sm->user_eap_method_index++].method;
1009 			wpa_printf(MSG_DEBUG, "EAP-FAST: try EAP type %u:%u",
1010 				   next_vendor, next_type);
1011 		} else {
1012 			next_vendor = EAP_VENDOR_IETF;
1013 			next_type = eap_fast_req_failure(sm, data);
1014 		}
1015 		eap_fast_phase2_init(sm, data, next_vendor, next_type);
1016 		return;
1017 	}
1018 
1019 	wpabuf_set(&buf, in_data, in_len);
1020 
1021 	if (m->check(sm, priv, &buf)) {
1022 		wpa_printf(MSG_DEBUG, "EAP-FAST: Phase2 check() asked to "
1023 			   "ignore the packet");
1024 		eap_fast_req_failure(sm, data);
1025 		return;
1026 	}
1027 
1028 	m->process(sm, priv, &buf);
1029 
1030 	if (!m->isDone(sm, priv))
1031 		return;
1032 
1033 	if (!m->isSuccess(sm, priv)) {
1034 		wpa_printf(MSG_DEBUG, "EAP-FAST: Phase2 method failed");
1035 		next_vendor = EAP_VENDOR_IETF;
1036 		next_type = eap_fast_req_failure(sm, data);
1037 		eap_fast_phase2_init(sm, data, next_vendor, next_type);
1038 		return;
1039 	}
1040 
1041 	switch (data->state) {
1042 	case PHASE2_ID:
1043 		if (eap_user_get(sm, sm->identity, sm->identity_len, 1) != 0) {
1044 			wpa_hexdump_ascii(MSG_DEBUG, "EAP-FAST: Phase2 "
1045 					  "Identity not found in the user "
1046 					  "database",
1047 					  sm->identity, sm->identity_len);
1048 			next_vendor = EAP_VENDOR_IETF;
1049 			next_type = eap_fast_req_failure(sm, data);
1050 			break;
1051 		}
1052 
1053 		eap_fast_state(data, PHASE2_METHOD);
1054 		if (data->anon_provisioning) {
1055 			/*
1056 			 * Only EAP-MSCHAPv2 is allowed for anonymous
1057 			 * provisioning.
1058 			 */
1059 			next_vendor = EAP_VENDOR_IETF;
1060 			next_type = EAP_TYPE_MSCHAPV2;
1061 			sm->user_eap_method_index = 0;
1062 		} else {
1063 			next_vendor = sm->user->methods[0].vendor;
1064 			next_type = sm->user->methods[0].method;
1065 			sm->user_eap_method_index = 1;
1066 		}
1067 		wpa_printf(MSG_DEBUG, "EAP-FAST: try EAP type %u:%u",
1068 			   next_vendor, next_type);
1069 		break;
1070 	case PHASE2_METHOD:
1071 	case CRYPTO_BINDING:
1072 		eap_fast_update_icmk(sm, data);
1073 		eap_fast_state(data, CRYPTO_BINDING);
1074 		data->eap_seq++;
1075 		next_vendor = EAP_VENDOR_IETF;
1076 		next_type = EAP_TYPE_NONE;
1077 #ifdef EAP_SERVER_TNC
1078 		if (sm->cfg->tnc && !data->tnc_started) {
1079 			wpa_printf(MSG_DEBUG, "EAP-FAST: Initialize TNC");
1080 			next_vendor = EAP_VENDOR_IETF;
1081 			next_type = EAP_TYPE_TNC;
1082 			data->tnc_started = 1;
1083 		}
1084 #endif /* EAP_SERVER_TNC */
1085 		break;
1086 	case FAILURE:
1087 		break;
1088 	default:
1089 		wpa_printf(MSG_DEBUG, "EAP-FAST: %s - unexpected state %d",
1090 			   __func__, data->state);
1091 		break;
1092 	}
1093 
1094 	eap_fast_phase2_init(sm, data, next_vendor, next_type);
1095 }
1096 
1097 
eap_fast_process_phase2_eap(struct eap_sm * sm,struct eap_fast_data * data,u8 * in_data,size_t in_len)1098 static void eap_fast_process_phase2_eap(struct eap_sm *sm,
1099 					struct eap_fast_data *data,
1100 					u8 *in_data, size_t in_len)
1101 {
1102 	struct eap_hdr *hdr;
1103 	size_t len;
1104 
1105 	hdr = (struct eap_hdr *) in_data;
1106 	if (in_len < (int) sizeof(*hdr)) {
1107 		wpa_printf(MSG_INFO, "EAP-FAST: Too short Phase 2 "
1108 			   "EAP frame (len=%lu)", (unsigned long) in_len);
1109 		eap_fast_req_failure(sm, data);
1110 		return;
1111 	}
1112 	len = be_to_host16(hdr->length);
1113 	if (len > in_len) {
1114 		wpa_printf(MSG_INFO, "EAP-FAST: Length mismatch in "
1115 			   "Phase 2 EAP frame (len=%lu hdr->length=%lu)",
1116 			   (unsigned long) in_len, (unsigned long) len);
1117 		eap_fast_req_failure(sm, data);
1118 		return;
1119 	}
1120 	wpa_printf(MSG_DEBUG, "EAP-FAST: Received Phase 2: code=%d "
1121 		   "identifier=%d length=%lu", hdr->code, hdr->identifier,
1122 		   (unsigned long) len);
1123 	switch (hdr->code) {
1124 	case EAP_CODE_RESPONSE:
1125 		eap_fast_process_phase2_response(sm, data, (u8 *) hdr, len);
1126 		break;
1127 	default:
1128 		wpa_printf(MSG_INFO, "EAP-FAST: Unexpected code=%d in "
1129 			   "Phase 2 EAP header", hdr->code);
1130 		break;
1131 	}
1132 }
1133 
1134 
eap_fast_parse_tlvs(struct wpabuf * data,struct eap_fast_tlv_parse * tlv)1135 static int eap_fast_parse_tlvs(struct wpabuf *data,
1136 			       struct eap_fast_tlv_parse *tlv)
1137 {
1138 	int mandatory, tlv_type, res;
1139 	size_t len;
1140 	u8 *pos, *end;
1141 
1142 	os_memset(tlv, 0, sizeof(*tlv));
1143 
1144 	pos = wpabuf_mhead(data);
1145 	end = pos + wpabuf_len(data);
1146 	while (end - pos > 4) {
1147 		mandatory = pos[0] & 0x80;
1148 		tlv_type = WPA_GET_BE16(pos) & 0x3fff;
1149 		pos += 2;
1150 		len = WPA_GET_BE16(pos);
1151 		pos += 2;
1152 		if (len > (size_t) (end - pos)) {
1153 			wpa_printf(MSG_INFO, "EAP-FAST: TLV overflow");
1154 			return -1;
1155 		}
1156 		wpa_printf(MSG_DEBUG, "EAP-FAST: Received Phase 2: "
1157 			   "TLV type %d length %u%s",
1158 			   tlv_type, (unsigned int) len,
1159 			   mandatory ? " (mandatory)" : "");
1160 
1161 		res = eap_fast_parse_tlv(tlv, tlv_type, pos, len);
1162 		if (res == -2)
1163 			break;
1164 		if (res < 0) {
1165 			if (mandatory) {
1166 				wpa_printf(MSG_DEBUG, "EAP-FAST: Nak unknown "
1167 					   "mandatory TLV type %d", tlv_type);
1168 				/* TODO: generate Nak TLV */
1169 				break;
1170 			} else {
1171 				wpa_printf(MSG_DEBUG, "EAP-FAST: Ignored "
1172 					   "unknown optional TLV type %d",
1173 					   tlv_type);
1174 			}
1175 		}
1176 
1177 		pos += len;
1178 	}
1179 
1180 	return 0;
1181 }
1182 
1183 
eap_fast_validate_crypto_binding(struct eap_fast_data * data,struct eap_tlv_crypto_binding_tlv * b,size_t bind_len)1184 static int eap_fast_validate_crypto_binding(
1185 	struct eap_fast_data *data, struct eap_tlv_crypto_binding_tlv *b,
1186 	size_t bind_len)
1187 {
1188 	u8 cmac[SHA1_MAC_LEN];
1189 
1190 	wpa_printf(MSG_DEBUG, "EAP-FAST: Reply Crypto-Binding TLV: "
1191 		   "Version %d Received Version %d SubType %d",
1192 		   b->version, b->received_version, b->subtype);
1193 	wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: NONCE",
1194 		    b->nonce, sizeof(b->nonce));
1195 	wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: Compound MAC",
1196 		    b->compound_mac, sizeof(b->compound_mac));
1197 
1198 	if (b->version != EAP_FAST_VERSION ||
1199 	    b->received_version != EAP_FAST_VERSION) {
1200 		wpa_printf(MSG_DEBUG, "EAP-FAST: Unexpected version "
1201 			   "in Crypto-Binding: version %d "
1202 			   "received_version %d", b->version,
1203 			   b->received_version);
1204 		return -1;
1205 	}
1206 
1207 	if (b->subtype != EAP_TLV_CRYPTO_BINDING_SUBTYPE_RESPONSE) {
1208 		wpa_printf(MSG_DEBUG, "EAP-FAST: Unexpected subtype in "
1209 			   "Crypto-Binding: %d", b->subtype);
1210 		return -1;
1211 	}
1212 
1213 	if (os_memcmp_const(data->crypto_binding_nonce, b->nonce, 31) != 0 ||
1214 	    (data->crypto_binding_nonce[31] | 1) != b->nonce[31]) {
1215 		wpa_printf(MSG_DEBUG, "EAP-FAST: Invalid nonce in "
1216 			   "Crypto-Binding");
1217 		return -1;
1218 	}
1219 
1220 	os_memcpy(cmac, b->compound_mac, sizeof(cmac));
1221 	os_memset(b->compound_mac, 0, sizeof(cmac));
1222 	wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: Crypto-Binding TLV for "
1223 		    "Compound MAC calculation",
1224 		    (u8 *) b, bind_len);
1225 	hmac_sha1(data->cmk, EAP_FAST_CMK_LEN, (u8 *) b, bind_len,
1226 		  b->compound_mac);
1227 	if (os_memcmp_const(cmac, b->compound_mac, sizeof(cmac)) != 0) {
1228 		wpa_hexdump(MSG_MSGDUMP,
1229 			    "EAP-FAST: Calculated Compound MAC",
1230 			    b->compound_mac, sizeof(cmac));
1231 		wpa_printf(MSG_INFO, "EAP-FAST: Compound MAC did not "
1232 			   "match");
1233 		return -1;
1234 	}
1235 
1236 	return 0;
1237 }
1238 
1239 
eap_fast_pac_type(u8 * pac,size_t len,u16 type)1240 static int eap_fast_pac_type(u8 *pac, size_t len, u16 type)
1241 {
1242 	struct eap_tlv_pac_type_tlv *tlv;
1243 
1244 	if (pac == NULL || len != sizeof(*tlv))
1245 		return 0;
1246 
1247 	tlv = (struct eap_tlv_pac_type_tlv *) pac;
1248 
1249 	return be_to_host16(tlv->tlv_type) == PAC_TYPE_PAC_TYPE &&
1250 		be_to_host16(tlv->length) == 2 &&
1251 		be_to_host16(tlv->pac_type) == type;
1252 }
1253 
1254 
eap_fast_process_phase2_tlvs(struct eap_sm * sm,struct eap_fast_data * data,struct wpabuf * in_data)1255 static void eap_fast_process_phase2_tlvs(struct eap_sm *sm,
1256 					 struct eap_fast_data *data,
1257 					 struct wpabuf *in_data)
1258 {
1259 	struct eap_fast_tlv_parse tlv;
1260 	int check_crypto_binding = data->state == CRYPTO_BINDING;
1261 
1262 	if (eap_fast_parse_tlvs(in_data, &tlv) < 0) {
1263 		wpa_printf(MSG_DEBUG, "EAP-FAST: Failed to parse received "
1264 			   "Phase 2 TLVs");
1265 		return;
1266 	}
1267 
1268 	if (tlv.result == EAP_TLV_RESULT_FAILURE) {
1269 		wpa_printf(MSG_DEBUG, "EAP-FAST: Result TLV indicated "
1270 			   "failure");
1271 		eap_fast_state(data, FAILURE);
1272 		return;
1273 	}
1274 
1275 	if (data->state == REQUEST_PAC) {
1276 		u16 type, len, res;
1277 		if (tlv.pac == NULL || tlv.pac_len < 6) {
1278 			wpa_printf(MSG_DEBUG, "EAP-FAST: No PAC "
1279 				   "Acknowledgement received");
1280 			eap_fast_state(data, FAILURE);
1281 			return;
1282 		}
1283 
1284 		type = WPA_GET_BE16(tlv.pac);
1285 		len = WPA_GET_BE16(tlv.pac + 2);
1286 		res = WPA_GET_BE16(tlv.pac + 4);
1287 
1288 		if (type != PAC_TYPE_PAC_ACKNOWLEDGEMENT || len != 2 ||
1289 		    res != EAP_TLV_RESULT_SUCCESS) {
1290 			wpa_printf(MSG_DEBUG, "EAP-FAST: PAC TLV did not "
1291 				   "contain acknowledgement");
1292 			eap_fast_state(data, FAILURE);
1293 			return;
1294 		}
1295 
1296 		wpa_printf(MSG_DEBUG, "EAP-FAST: PAC-Acknowledgement received "
1297 			   "- PAC provisioning succeeded");
1298 		eap_fast_state(data, (data->anon_provisioning ||
1299 				      data->send_new_pac == 2) ?
1300 			       FAILURE : SUCCESS);
1301 		return;
1302 	}
1303 
1304 	if (check_crypto_binding) {
1305 		if (tlv.crypto_binding == NULL) {
1306 			wpa_printf(MSG_DEBUG, "EAP-FAST: No Crypto-Binding "
1307 				   "TLV received");
1308 			eap_fast_state(data, FAILURE);
1309 			return;
1310 		}
1311 
1312 		if (data->final_result &&
1313 		    tlv.result != EAP_TLV_RESULT_SUCCESS) {
1314 			wpa_printf(MSG_DEBUG, "EAP-FAST: Crypto-Binding TLV "
1315 				   "without Success Result");
1316 			eap_fast_state(data, FAILURE);
1317 			return;
1318 		}
1319 
1320 		if (!data->final_result &&
1321 		    tlv.iresult != EAP_TLV_RESULT_SUCCESS) {
1322 			wpa_printf(MSG_DEBUG, "EAP-FAST: Crypto-Binding TLV "
1323 				   "without intermediate Success Result");
1324 			eap_fast_state(data, FAILURE);
1325 			return;
1326 		}
1327 
1328 		if (eap_fast_validate_crypto_binding(data, tlv.crypto_binding,
1329 						     tlv.crypto_binding_len)) {
1330 			eap_fast_state(data, FAILURE);
1331 			return;
1332 		}
1333 
1334 		wpa_printf(MSG_DEBUG, "EAP-FAST: Valid Crypto-Binding TLV "
1335 			   "received");
1336 		if (data->final_result) {
1337 			wpa_printf(MSG_DEBUG, "EAP-FAST: Authentication "
1338 				   "completed successfully");
1339 		}
1340 
1341 		if (data->anon_provisioning &&
1342 		    sm->cfg->eap_fast_prov != ANON_PROV &&
1343 		    sm->cfg->eap_fast_prov != BOTH_PROV) {
1344 			wpa_printf(MSG_DEBUG, "EAP-FAST: Client is trying to "
1345 				   "use unauthenticated provisioning which is "
1346 				   "disabled");
1347 			eap_fast_state(data, FAILURE);
1348 			return;
1349 		}
1350 
1351 		if (sm->cfg->eap_fast_prov != AUTH_PROV &&
1352 		    sm->cfg->eap_fast_prov != BOTH_PROV &&
1353 		    tlv.request_action == EAP_TLV_ACTION_PROCESS_TLV &&
1354 		    eap_fast_pac_type(tlv.pac, tlv.pac_len,
1355 				      PAC_TYPE_TUNNEL_PAC)) {
1356 			wpa_printf(MSG_DEBUG, "EAP-FAST: Client is trying to "
1357 				   "use authenticated provisioning which is "
1358 				   "disabled");
1359 			eap_fast_state(data, FAILURE);
1360 			return;
1361 		}
1362 
1363 		if (data->anon_provisioning ||
1364 		    (tlv.request_action == EAP_TLV_ACTION_PROCESS_TLV &&
1365 		     eap_fast_pac_type(tlv.pac, tlv.pac_len,
1366 				       PAC_TYPE_TUNNEL_PAC))) {
1367 			wpa_printf(MSG_DEBUG, "EAP-FAST: Requested a new "
1368 				   "Tunnel PAC");
1369 			eap_fast_state(data, REQUEST_PAC);
1370 		} else if (data->send_new_pac) {
1371 			wpa_printf(MSG_DEBUG, "EAP-FAST: Server triggered "
1372 				   "re-keying of Tunnel PAC");
1373 			eap_fast_state(data, REQUEST_PAC);
1374 		} else if (data->final_result)
1375 			eap_fast_state(data, SUCCESS);
1376 	}
1377 
1378 	if (tlv.eap_payload_tlv) {
1379 		eap_fast_process_phase2_eap(sm, data, tlv.eap_payload_tlv,
1380 					    tlv.eap_payload_tlv_len);
1381 	}
1382 }
1383 
1384 
eap_fast_process_phase2(struct eap_sm * sm,struct eap_fast_data * data,struct wpabuf * in_buf)1385 static void eap_fast_process_phase2(struct eap_sm *sm,
1386 				    struct eap_fast_data *data,
1387 				    struct wpabuf *in_buf)
1388 {
1389 	struct wpabuf *in_decrypted;
1390 
1391 	wpa_printf(MSG_DEBUG, "EAP-FAST: Received %lu bytes encrypted data for"
1392 		   " Phase 2", (unsigned long) wpabuf_len(in_buf));
1393 
1394 	if (data->pending_phase2_resp) {
1395 		wpa_printf(MSG_DEBUG, "EAP-PEAP: Pending Phase 2 response - "
1396 			   "skip decryption and use old data");
1397 		eap_fast_process_phase2_tlvs(sm, data,
1398 					     data->pending_phase2_resp);
1399 		wpabuf_free(data->pending_phase2_resp);
1400 		data->pending_phase2_resp = NULL;
1401 		return;
1402 	}
1403 
1404 	in_decrypted = tls_connection_decrypt(sm->cfg->ssl_ctx, data->ssl.conn,
1405 					      in_buf);
1406 	if (in_decrypted == NULL) {
1407 		wpa_printf(MSG_INFO, "EAP-FAST: Failed to decrypt Phase 2 "
1408 			   "data");
1409 		eap_fast_state(data, FAILURE);
1410 		return;
1411 	}
1412 
1413 	wpa_hexdump_buf_key(MSG_DEBUG, "EAP-FAST: Decrypted Phase 2 TLVs",
1414 			    in_decrypted);
1415 
1416 	eap_fast_process_phase2_tlvs(sm, data, in_decrypted);
1417 
1418 	if (sm->method_pending == METHOD_PENDING_WAIT) {
1419 		wpa_printf(MSG_DEBUG, "EAP-FAST: Phase2 method is in "
1420 			   "pending wait state - save decrypted response");
1421 		wpabuf_free(data->pending_phase2_resp);
1422 		data->pending_phase2_resp = in_decrypted;
1423 		return;
1424 	}
1425 
1426 	wpabuf_free(in_decrypted);
1427 }
1428 
1429 
eap_fast_process_version(struct eap_sm * sm,void * priv,int peer_version)1430 static int eap_fast_process_version(struct eap_sm *sm, void *priv,
1431 				    int peer_version)
1432 {
1433 	struct eap_fast_data *data = priv;
1434 
1435 	data->peer_version = peer_version;
1436 
1437 	if (data->force_version >= 0 && peer_version != data->force_version) {
1438 		wpa_printf(MSG_INFO, "EAP-FAST: peer did not select the forced"
1439 			   " version (forced=%d peer=%d) - reject",
1440 			   data->force_version, peer_version);
1441 		return -1;
1442 	}
1443 
1444 	if (peer_version < data->fast_version) {
1445 		wpa_printf(MSG_DEBUG, "EAP-FAST: peer ver=%d, own ver=%d; "
1446 			   "use version %d",
1447 			   peer_version, data->fast_version, peer_version);
1448 		data->fast_version = peer_version;
1449 	}
1450 
1451 	return 0;
1452 }
1453 
1454 
eap_fast_process_phase1(struct eap_sm * sm,struct eap_fast_data * data)1455 static int eap_fast_process_phase1(struct eap_sm *sm,
1456 				   struct eap_fast_data *data)
1457 {
1458 	if (eap_server_tls_phase1(sm, &data->ssl) < 0) {
1459 		wpa_printf(MSG_INFO, "EAP-FAST: TLS processing failed");
1460 		eap_fast_state(data, FAILURE);
1461 		return -1;
1462 	}
1463 
1464 	if (!tls_connection_established(sm->cfg->ssl_ctx, data->ssl.conn) ||
1465 	    wpabuf_len(data->ssl.tls_out) > 0)
1466 		return 1;
1467 
1468 	/*
1469 	 * Phase 1 was completed with the received message (e.g., when using
1470 	 * abbreviated handshake), so Phase 2 can be started immediately
1471 	 * without having to send through an empty message to the peer.
1472 	 */
1473 
1474 	return eap_fast_phase1_done(sm, data);
1475 }
1476 
1477 
eap_fast_process_phase2_start(struct eap_sm * sm,struct eap_fast_data * data)1478 static int eap_fast_process_phase2_start(struct eap_sm *sm,
1479 					 struct eap_fast_data *data)
1480 {
1481 	int next_vendor;
1482 	enum eap_type next_type;
1483 
1484 	if (data->identity) {
1485 		os_free(sm->identity);
1486 		sm->identity = data->identity;
1487 		data->identity = NULL;
1488 		sm->identity_len = data->identity_len;
1489 		data->identity_len = 0;
1490 		sm->require_identity_match = 1;
1491 		if (eap_user_get(sm, sm->identity, sm->identity_len, 1) != 0) {
1492 			wpa_hexdump_ascii(MSG_DEBUG, "EAP-FAST: "
1493 					  "Phase2 Identity not found "
1494 					  "in the user database",
1495 					  sm->identity, sm->identity_len);
1496 			next_vendor = EAP_VENDOR_IETF;
1497 			next_type = eap_fast_req_failure(sm, data);
1498 		} else {
1499 			wpa_printf(MSG_DEBUG, "EAP-FAST: Identity already "
1500 				   "known - skip Phase 2 Identity Request");
1501 			next_vendor = sm->user->methods[0].vendor;
1502 			next_type = sm->user->methods[0].method;
1503 			sm->user_eap_method_index = 1;
1504 		}
1505 
1506 		eap_fast_state(data, PHASE2_METHOD);
1507 	} else {
1508 		eap_fast_state(data, PHASE2_ID);
1509 		next_vendor = EAP_VENDOR_IETF;
1510 		next_type = EAP_TYPE_IDENTITY;
1511 	}
1512 
1513 	return eap_fast_phase2_init(sm, data, next_vendor, next_type);
1514 }
1515 
1516 
eap_fast_process_msg(struct eap_sm * sm,void * priv,const struct wpabuf * respData)1517 static void eap_fast_process_msg(struct eap_sm *sm, void *priv,
1518 				 const struct wpabuf *respData)
1519 {
1520 	struct eap_fast_data *data = priv;
1521 
1522 	switch (data->state) {
1523 	case PHASE1:
1524 		if (eap_fast_process_phase1(sm, data))
1525 			break;
1526 
1527 		/* fall through */
1528 	case PHASE2_START:
1529 		eap_fast_process_phase2_start(sm, data);
1530 		break;
1531 	case PHASE2_ID:
1532 	case PHASE2_METHOD:
1533 	case CRYPTO_BINDING:
1534 	case REQUEST_PAC:
1535 		eap_fast_process_phase2(sm, data, data->ssl.tls_in);
1536 		break;
1537 	default:
1538 		wpa_printf(MSG_DEBUG, "EAP-FAST: Unexpected state %d in %s",
1539 			   data->state, __func__);
1540 		break;
1541 	}
1542 }
1543 
1544 
eap_fast_process(struct eap_sm * sm,void * priv,struct wpabuf * respData)1545 static void eap_fast_process(struct eap_sm *sm, void *priv,
1546 			     struct wpabuf *respData)
1547 {
1548 	struct eap_fast_data *data = priv;
1549 	if (eap_server_tls_process(sm, &data->ssl, respData, data,
1550 				   EAP_TYPE_FAST, eap_fast_process_version,
1551 				   eap_fast_process_msg) < 0)
1552 		eap_fast_state(data, FAILURE);
1553 }
1554 
1555 
eap_fast_isDone(struct eap_sm * sm,void * priv)1556 static bool eap_fast_isDone(struct eap_sm *sm, void *priv)
1557 {
1558 	struct eap_fast_data *data = priv;
1559 	return data->state == SUCCESS || data->state == FAILURE;
1560 }
1561 
1562 
eap_fast_getKey(struct eap_sm * sm,void * priv,size_t * len)1563 static u8 * eap_fast_getKey(struct eap_sm *sm, void *priv, size_t *len)
1564 {
1565 	struct eap_fast_data *data = priv;
1566 	u8 *eapKeyData;
1567 
1568 	if (data->state != SUCCESS)
1569 		return NULL;
1570 
1571 	eapKeyData = os_malloc(EAP_FAST_KEY_LEN);
1572 	if (eapKeyData == NULL)
1573 		return NULL;
1574 
1575 	if (eap_fast_derive_eap_msk(data->simck, eapKeyData) < 0) {
1576 		os_free(eapKeyData);
1577 		return NULL;
1578 	}
1579 	*len = EAP_FAST_KEY_LEN;
1580 
1581 	return eapKeyData;
1582 }
1583 
1584 
eap_fast_get_emsk(struct eap_sm * sm,void * priv,size_t * len)1585 static u8 * eap_fast_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
1586 {
1587 	struct eap_fast_data *data = priv;
1588 	u8 *eapKeyData;
1589 
1590 	if (data->state != SUCCESS)
1591 		return NULL;
1592 
1593 	eapKeyData = os_malloc(EAP_EMSK_LEN);
1594 	if (eapKeyData == NULL)
1595 		return NULL;
1596 
1597 	if (eap_fast_derive_eap_emsk(data->simck, eapKeyData) < 0) {
1598 		os_free(eapKeyData);
1599 		return NULL;
1600 	}
1601 	*len = EAP_EMSK_LEN;
1602 
1603 	return eapKeyData;
1604 }
1605 
1606 
eap_fast_isSuccess(struct eap_sm * sm,void * priv)1607 static bool eap_fast_isSuccess(struct eap_sm *sm, void *priv)
1608 {
1609 	struct eap_fast_data *data = priv;
1610 	return data->state == SUCCESS;
1611 }
1612 
1613 
eap_fast_get_session_id(struct eap_sm * sm,void * priv,size_t * len)1614 static u8 * eap_fast_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
1615 {
1616 	struct eap_fast_data *data = priv;
1617 
1618 	if (data->state != SUCCESS)
1619 		return NULL;
1620 
1621 	return eap_server_tls_derive_session_id(sm, &data->ssl, EAP_TYPE_FAST,
1622 						len);
1623 }
1624 
1625 
eap_server_fast_register(void)1626 int eap_server_fast_register(void)
1627 {
1628 	struct eap_method *eap;
1629 
1630 	eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
1631 				      EAP_VENDOR_IETF, EAP_TYPE_FAST, "FAST");
1632 	if (eap == NULL)
1633 		return -1;
1634 
1635 	eap->init = eap_fast_init;
1636 	eap->reset = eap_fast_reset;
1637 	eap->buildReq = eap_fast_buildReq;
1638 	eap->check = eap_fast_check;
1639 	eap->process = eap_fast_process;
1640 	eap->isDone = eap_fast_isDone;
1641 	eap->getKey = eap_fast_getKey;
1642 	eap->get_emsk = eap_fast_get_emsk;
1643 	eap->isSuccess = eap_fast_isSuccess;
1644 	eap->getSessionId = eap_fast_get_session_id;
1645 
1646 	return eap_server_method_register(eap);
1647 }
1648