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 EapType 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 (pos + 1 < end) {
184 		if (pos + 2 + pos[1] > end)
185 			break;
186 
187 		switch (*pos) {
188 		case PAC_OPAQUE_TYPE_PAD:
189 			goto done;
190 		case PAC_OPAQUE_TYPE_KEY:
191 			if (pos[1] != EAP_FAST_PAC_KEY_LEN) {
192 				wpa_printf(MSG_DEBUG, "EAP-FAST: Invalid "
193 					   "PAC-Key length %d", pos[1]);
194 				os_free(buf);
195 				return -1;
196 			}
197 			pac_key = pos + 2;
198 			wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: PAC-Key from "
199 					"decrypted PAC-Opaque",
200 					pac_key, EAP_FAST_PAC_KEY_LEN);
201 			break;
202 		case PAC_OPAQUE_TYPE_LIFETIME:
203 			if (pos[1] != 4) {
204 				wpa_printf(MSG_DEBUG, "EAP-FAST: Invalid "
205 					   "PAC-Key lifetime length %d",
206 					   pos[1]);
207 				os_free(buf);
208 				return -1;
209 			}
210 			lifetime = WPA_GET_BE32(pos + 2);
211 			break;
212 		case PAC_OPAQUE_TYPE_IDENTITY:
213 			identity = pos + 2;
214 			identity_len = pos[1];
215 			break;
216 		}
217 
218 		pos += 2 + pos[1];
219 	}
220 done:
221 
222 	if (pac_key == NULL) {
223 		wpa_printf(MSG_DEBUG, "EAP-FAST: No PAC-Key included in "
224 			   "PAC-Opaque");
225 		os_free(buf);
226 		return -1;
227 	}
228 
229 	if (identity) {
230 		wpa_hexdump_ascii(MSG_DEBUG, "EAP-FAST: Identity from "
231 				  "PAC-Opaque", identity, identity_len);
232 		os_free(data->identity);
233 		data->identity = os_malloc(identity_len);
234 		if (data->identity) {
235 			os_memcpy(data->identity, identity, identity_len);
236 			data->identity_len = identity_len;
237 		}
238 	}
239 
240 	if (os_get_time(&now) < 0 || lifetime <= 0 || now.sec > lifetime) {
241 		wpa_printf(MSG_DEBUG, "EAP-FAST: PAC-Key not valid anymore "
242 			   "(lifetime=%ld now=%ld)", lifetime, now.sec);
243 		data->send_new_pac = 2;
244 		/*
245 		 * Allow PAC to be used to allow a PAC update with some level
246 		 * of server authentication (i.e., do not fall back to full TLS
247 		 * handshake since we cannot be sure that the peer would be
248 		 * able to validate server certificate now). However, reject
249 		 * the authentication since the PAC was not valid anymore. Peer
250 		 * can connect again with the newly provisioned PAC after this.
251 		 */
252 	} else if (lifetime - now.sec < data->pac_key_refresh_time) {
253 		wpa_printf(MSG_DEBUG, "EAP-FAST: PAC-Key soft timeout; send "
254 			   "an update if authentication succeeds");
255 		data->send_new_pac = 1;
256 	}
257 
258 	eap_fast_derive_master_secret(pac_key, server_random, client_random,
259 				      master_secret);
260 
261 	os_free(buf);
262 
263 	return 1;
264 }
265 
266 
eap_fast_derive_key_auth(struct eap_sm * sm,struct eap_fast_data * data)267 static void eap_fast_derive_key_auth(struct eap_sm *sm,
268 				     struct eap_fast_data *data)
269 {
270 	u8 *sks;
271 
272 	/* RFC 4851, Section 5.1:
273 	 * Extra key material after TLS key_block: session_key_seed[40]
274 	 */
275 
276 	sks = eap_fast_derive_key(sm->ssl_ctx, data->ssl.conn, "key expansion",
277 				  EAP_FAST_SKS_LEN);
278 	if (sks == NULL) {
279 		wpa_printf(MSG_DEBUG, "EAP-FAST: Failed to derive "
280 			   "session_key_seed");
281 		return;
282 	}
283 
284 	/*
285 	 * RFC 4851, Section 5.2:
286 	 * S-IMCK[0] = session_key_seed
287 	 */
288 	wpa_hexdump_key(MSG_DEBUG,
289 			"EAP-FAST: session_key_seed (SKS = S-IMCK[0])",
290 			sks, EAP_FAST_SKS_LEN);
291 	data->simck_idx = 0;
292 	os_memcpy(data->simck, sks, EAP_FAST_SIMCK_LEN);
293 	os_free(sks);
294 }
295 
296 
eap_fast_derive_key_provisioning(struct eap_sm * sm,struct eap_fast_data * data)297 static void eap_fast_derive_key_provisioning(struct eap_sm *sm,
298 					     struct eap_fast_data *data)
299 {
300 	os_free(data->key_block_p);
301 	data->key_block_p = (struct eap_fast_key_block_provisioning *)
302 		eap_fast_derive_key(sm->ssl_ctx, data->ssl.conn,
303 				    "key expansion",
304 				    sizeof(*data->key_block_p));
305 	if (data->key_block_p == NULL) {
306 		wpa_printf(MSG_DEBUG, "EAP-FAST: Failed to derive key block");
307 		return;
308 	}
309 	/*
310 	 * RFC 4851, Section 5.2:
311 	 * S-IMCK[0] = session_key_seed
312 	 */
313 	wpa_hexdump_key(MSG_DEBUG,
314 			"EAP-FAST: session_key_seed (SKS = S-IMCK[0])",
315 			data->key_block_p->session_key_seed,
316 			sizeof(data->key_block_p->session_key_seed));
317 	data->simck_idx = 0;
318 	os_memcpy(data->simck, data->key_block_p->session_key_seed,
319 		  EAP_FAST_SIMCK_LEN);
320 	wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: server_challenge",
321 			data->key_block_p->server_challenge,
322 			sizeof(data->key_block_p->server_challenge));
323 	wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: client_challenge",
324 			data->key_block_p->client_challenge,
325 			sizeof(data->key_block_p->client_challenge));
326 }
327 
328 
eap_fast_get_phase2_key(struct eap_sm * sm,struct eap_fast_data * data,u8 * isk,size_t isk_len)329 static int eap_fast_get_phase2_key(struct eap_sm *sm,
330 				   struct eap_fast_data *data,
331 				   u8 *isk, size_t isk_len)
332 {
333 	u8 *key;
334 	size_t key_len;
335 
336 	os_memset(isk, 0, isk_len);
337 
338 	if (data->phase2_method == NULL || data->phase2_priv == NULL) {
339 		wpa_printf(MSG_DEBUG, "EAP-FAST: Phase 2 method not "
340 			   "available");
341 		return -1;
342 	}
343 
344 	if (data->phase2_method->getKey == NULL)
345 		return 0;
346 
347 	if ((key = data->phase2_method->getKey(sm, data->phase2_priv,
348 					       &key_len)) == NULL) {
349 		wpa_printf(MSG_DEBUG, "EAP-FAST: Could not get key material "
350 			   "from Phase 2");
351 		return -1;
352 	}
353 
354 	if (key_len > isk_len)
355 		key_len = isk_len;
356 	if (key_len == 32 &&
357 	    data->phase2_method->vendor == EAP_VENDOR_IETF &&
358 	    data->phase2_method->method == EAP_TYPE_MSCHAPV2) {
359 		/*
360 		 * EAP-FAST uses reverse order for MS-MPPE keys when deriving
361 		 * MSK from EAP-MSCHAPv2. Swap the keys here to get the correct
362 		 * ISK for EAP-FAST cryptobinding.
363 		 */
364 		os_memcpy(isk, key + 16, 16);
365 		os_memcpy(isk + 16, key, 16);
366 	} else
367 		os_memcpy(isk, key, key_len);
368 	os_free(key);
369 
370 	return 0;
371 }
372 
373 
eap_fast_update_icmk(struct eap_sm * sm,struct eap_fast_data * data)374 static int eap_fast_update_icmk(struct eap_sm *sm, struct eap_fast_data *data)
375 {
376 	u8 isk[32], imck[60];
377 
378 	wpa_printf(MSG_DEBUG, "EAP-FAST: Deriving ICMK[%d] (S-IMCK and CMK)",
379 		   data->simck_idx + 1);
380 
381 	/*
382 	 * RFC 4851, Section 5.2:
383 	 * IMCK[j] = T-PRF(S-IMCK[j-1], "Inner Methods Compound Keys",
384 	 *                 MSK[j], 60)
385 	 * S-IMCK[j] = first 40 octets of IMCK[j]
386 	 * CMK[j] = last 20 octets of IMCK[j]
387 	 */
388 
389 	if (eap_fast_get_phase2_key(sm, data, isk, sizeof(isk)) < 0)
390 		return -1;
391 	wpa_hexdump_key(MSG_MSGDUMP, "EAP-FAST: ISK[j]", isk, sizeof(isk));
392 	sha1_t_prf(data->simck, EAP_FAST_SIMCK_LEN,
393 		   "Inner Methods Compound Keys",
394 		   isk, sizeof(isk), imck, sizeof(imck));
395 	data->simck_idx++;
396 	os_memcpy(data->simck, imck, EAP_FAST_SIMCK_LEN);
397 	wpa_hexdump_key(MSG_MSGDUMP, "EAP-FAST: S-IMCK[j]",
398 			data->simck, EAP_FAST_SIMCK_LEN);
399 	os_memcpy(data->cmk, imck + EAP_FAST_SIMCK_LEN, EAP_FAST_CMK_LEN);
400 	wpa_hexdump_key(MSG_MSGDUMP, "EAP-FAST: CMK[j]",
401 			data->cmk, EAP_FAST_CMK_LEN);
402 
403 	return 0;
404 }
405 
406 
eap_fast_init(struct eap_sm * sm)407 static void * eap_fast_init(struct eap_sm *sm)
408 {
409 	struct eap_fast_data *data;
410 	u8 ciphers[5] = {
411 		TLS_CIPHER_ANON_DH_AES128_SHA,
412 		TLS_CIPHER_AES128_SHA,
413 		TLS_CIPHER_RSA_DHE_AES128_SHA,
414 		TLS_CIPHER_RC4_SHA,
415 		TLS_CIPHER_NONE
416 	};
417 
418 	data = os_zalloc(sizeof(*data));
419 	if (data == NULL)
420 		return NULL;
421 	data->fast_version = EAP_FAST_VERSION;
422 	data->force_version = -1;
423 	if (sm->user && sm->user->force_version >= 0) {
424 		data->force_version = sm->user->force_version;
425 		wpa_printf(MSG_DEBUG, "EAP-FAST: forcing version %d",
426 			   data->force_version);
427 		data->fast_version = data->force_version;
428 	}
429 	data->state = START;
430 
431 	if (eap_server_tls_ssl_init(sm, &data->ssl, 0)) {
432 		wpa_printf(MSG_INFO, "EAP-FAST: Failed to initialize SSL.");
433 		eap_fast_reset(sm, data);
434 		return NULL;
435 	}
436 
437 	if (tls_connection_set_cipher_list(sm->ssl_ctx, data->ssl.conn,
438 					   ciphers) < 0) {
439 		wpa_printf(MSG_INFO, "EAP-FAST: Failed to set TLS cipher "
440 			   "suites");
441 		eap_fast_reset(sm, data);
442 		return NULL;
443 	}
444 
445 	if (tls_connection_set_session_ticket_cb(sm->ssl_ctx, data->ssl.conn,
446 						 eap_fast_session_ticket_cb,
447 						 data) < 0) {
448 		wpa_printf(MSG_INFO, "EAP-FAST: Failed to set SessionTicket "
449 			   "callback");
450 		eap_fast_reset(sm, data);
451 		return NULL;
452 	}
453 
454 	if (sm->pac_opaque_encr_key == NULL) {
455 		wpa_printf(MSG_INFO, "EAP-FAST: No PAC-Opaque encryption key "
456 			   "configured");
457 		eap_fast_reset(sm, data);
458 		return NULL;
459 	}
460 	os_memcpy(data->pac_opaque_encr, sm->pac_opaque_encr_key,
461 		  sizeof(data->pac_opaque_encr));
462 
463 	if (sm->eap_fast_a_id == NULL) {
464 		wpa_printf(MSG_INFO, "EAP-FAST: No A-ID configured");
465 		eap_fast_reset(sm, data);
466 		return NULL;
467 	}
468 	data->srv_id = os_malloc(sm->eap_fast_a_id_len);
469 	if (data->srv_id == NULL) {
470 		eap_fast_reset(sm, data);
471 		return NULL;
472 	}
473 	os_memcpy(data->srv_id, sm->eap_fast_a_id, sm->eap_fast_a_id_len);
474 	data->srv_id_len = sm->eap_fast_a_id_len;
475 
476 	if (sm->eap_fast_a_id_info == NULL) {
477 		wpa_printf(MSG_INFO, "EAP-FAST: No A-ID-Info configured");
478 		eap_fast_reset(sm, data);
479 		return NULL;
480 	}
481 	data->srv_id_info = os_strdup(sm->eap_fast_a_id_info);
482 	if (data->srv_id_info == NULL) {
483 		eap_fast_reset(sm, data);
484 		return NULL;
485 	}
486 
487 	/* PAC-Key lifetime in seconds (hard limit) */
488 	data->pac_key_lifetime = sm->pac_key_lifetime;
489 
490 	/*
491 	 * PAC-Key refresh time in seconds (soft limit on remaining hard
492 	 * limit). The server will generate a new PAC-Key when this number of
493 	 * seconds (or fewer) of the lifetime remains.
494 	 */
495 	data->pac_key_refresh_time = sm->pac_key_refresh_time;
496 
497 	return data;
498 }
499 
500 
eap_fast_reset(struct eap_sm * sm,void * priv)501 static void eap_fast_reset(struct eap_sm *sm, void *priv)
502 {
503 	struct eap_fast_data *data = priv;
504 	if (data == NULL)
505 		return;
506 	if (data->phase2_priv && data->phase2_method)
507 		data->phase2_method->reset(sm, data->phase2_priv);
508 	eap_server_tls_ssl_deinit(sm, &data->ssl);
509 	os_free(data->srv_id);
510 	os_free(data->srv_id_info);
511 	os_free(data->key_block_p);
512 	wpabuf_free(data->pending_phase2_resp);
513 	os_free(data->identity);
514 	bin_clear_free(data, sizeof(*data));
515 }
516 
517 
eap_fast_build_start(struct eap_sm * sm,struct eap_fast_data * data,u8 id)518 static struct wpabuf * eap_fast_build_start(struct eap_sm *sm,
519 					    struct eap_fast_data *data, u8 id)
520 {
521 	struct wpabuf *req;
522 
523 	req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_FAST,
524 			    1 + sizeof(struct pac_tlv_hdr) + data->srv_id_len,
525 			    EAP_CODE_REQUEST, id);
526 	if (req == NULL) {
527 		wpa_printf(MSG_ERROR, "EAP-FAST: Failed to allocate memory for"
528 			   " request");
529 		eap_fast_state(data, FAILURE);
530 		return NULL;
531 	}
532 
533 	wpabuf_put_u8(req, EAP_TLS_FLAGS_START | data->fast_version);
534 
535 	/* RFC 4851, 4.1.1. Authority ID Data */
536 	eap_fast_put_tlv(req, PAC_TYPE_A_ID, data->srv_id, data->srv_id_len);
537 
538 	eap_fast_state(data, PHASE1);
539 
540 	return req;
541 }
542 
543 
eap_fast_phase1_done(struct eap_sm * sm,struct eap_fast_data * data)544 static int eap_fast_phase1_done(struct eap_sm *sm, struct eap_fast_data *data)
545 {
546 	char cipher[64];
547 
548 	wpa_printf(MSG_DEBUG, "EAP-FAST: Phase1 done, starting Phase2");
549 
550 	if (tls_get_cipher(sm->ssl_ctx, data->ssl.conn, cipher, sizeof(cipher))
551 	    < 0) {
552 		wpa_printf(MSG_DEBUG, "EAP-FAST: Failed to get cipher "
553 			   "information");
554 		eap_fast_state(data, FAILURE);
555 		return -1;
556 	}
557 	data->anon_provisioning = os_strstr(cipher, "ADH") != NULL;
558 
559 	if (data->anon_provisioning) {
560 		wpa_printf(MSG_DEBUG, "EAP-FAST: Anonymous provisioning");
561 		eap_fast_derive_key_provisioning(sm, data);
562 	} else
563 		eap_fast_derive_key_auth(sm, data);
564 
565 	eap_fast_state(data, PHASE2_START);
566 
567 	return 0;
568 }
569 
570 
eap_fast_build_phase2_req(struct eap_sm * sm,struct eap_fast_data * data,u8 id)571 static struct wpabuf * eap_fast_build_phase2_req(struct eap_sm *sm,
572 						 struct eap_fast_data *data,
573 						 u8 id)
574 {
575 	struct wpabuf *req;
576 
577 	if (data->phase2_priv == NULL) {
578 		wpa_printf(MSG_DEBUG, "EAP-FAST: Phase 2 method not "
579 			   "initialized");
580 		return NULL;
581 	}
582 	req = data->phase2_method->buildReq(sm, data->phase2_priv, id);
583 	if (req == NULL)
584 		return NULL;
585 
586 	wpa_hexdump_buf_key(MSG_MSGDUMP, "EAP-FAST: Phase 2 EAP-Request", req);
587 	return eap_fast_tlv_eap_payload(req);
588 }
589 
590 
eap_fast_build_crypto_binding(struct eap_sm * sm,struct eap_fast_data * data)591 static struct wpabuf * eap_fast_build_crypto_binding(
592 	struct eap_sm *sm, struct eap_fast_data *data)
593 {
594 	struct wpabuf *buf;
595 	struct eap_tlv_result_tlv *result;
596 	struct eap_tlv_crypto_binding_tlv *binding;
597 
598 	buf = wpabuf_alloc(2 * sizeof(*result) + sizeof(*binding));
599 	if (buf == NULL)
600 		return NULL;
601 
602 	if (data->send_new_pac || data->anon_provisioning ||
603 	    data->phase2_method)
604 		data->final_result = 0;
605 	else
606 		data->final_result = 1;
607 
608 	if (!data->final_result || data->eap_seq > 1) {
609 		/* Intermediate-Result */
610 		wpa_printf(MSG_DEBUG, "EAP-FAST: Add Intermediate-Result TLV "
611 			   "(status=SUCCESS)");
612 		result = wpabuf_put(buf, sizeof(*result));
613 		result->tlv_type = host_to_be16(
614 			EAP_TLV_TYPE_MANDATORY |
615 			EAP_TLV_INTERMEDIATE_RESULT_TLV);
616 		result->length = host_to_be16(2);
617 		result->status = host_to_be16(EAP_TLV_RESULT_SUCCESS);
618 	}
619 
620 	if (data->final_result) {
621 		/* Result TLV */
622 		wpa_printf(MSG_DEBUG, "EAP-FAST: Add Result TLV "
623 			   "(status=SUCCESS)");
624 		result = wpabuf_put(buf, sizeof(*result));
625 		result->tlv_type = host_to_be16(EAP_TLV_TYPE_MANDATORY |
626 						EAP_TLV_RESULT_TLV);
627 		result->length = host_to_be16(2);
628 		result->status = host_to_be16(EAP_TLV_RESULT_SUCCESS);
629 	}
630 
631 	/* Crypto-Binding TLV */
632 	binding = wpabuf_put(buf, sizeof(*binding));
633 	binding->tlv_type = host_to_be16(EAP_TLV_TYPE_MANDATORY |
634 					 EAP_TLV_CRYPTO_BINDING_TLV);
635 	binding->length = host_to_be16(sizeof(*binding) -
636 				       sizeof(struct eap_tlv_hdr));
637 	binding->version = EAP_FAST_VERSION;
638 	binding->received_version = data->peer_version;
639 	binding->subtype = EAP_TLV_CRYPTO_BINDING_SUBTYPE_REQUEST;
640 	if (random_get_bytes(binding->nonce, sizeof(binding->nonce)) < 0) {
641 		wpabuf_free(buf);
642 		return NULL;
643 	}
644 
645 	/*
646 	 * RFC 4851, Section 4.2.8:
647 	 * The nonce in a request MUST have its least significant bit set to 0.
648 	 */
649 	binding->nonce[sizeof(binding->nonce) - 1] &= ~0x01;
650 
651 	os_memcpy(data->crypto_binding_nonce, binding->nonce,
652 		  sizeof(binding->nonce));
653 
654 	/*
655 	 * RFC 4851, Section 5.3:
656 	 * CMK = CMK[j]
657 	 * Compound-MAC = HMAC-SHA1( CMK, Crypto-Binding TLV )
658 	 */
659 
660 	hmac_sha1(data->cmk, EAP_FAST_CMK_LEN,
661 		  (u8 *) binding, sizeof(*binding),
662 		  binding->compound_mac);
663 
664 	wpa_printf(MSG_DEBUG, "EAP-FAST: Add Crypto-Binding TLV: Version %d "
665 		   "Received Version %d SubType %d",
666 		   binding->version, binding->received_version,
667 		   binding->subtype);
668 	wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: NONCE",
669 		    binding->nonce, sizeof(binding->nonce));
670 	wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: Compound MAC",
671 		    binding->compound_mac, sizeof(binding->compound_mac));
672 
673 	return buf;
674 }
675 
676 
eap_fast_build_pac(struct eap_sm * sm,struct eap_fast_data * data)677 static struct wpabuf * eap_fast_build_pac(struct eap_sm *sm,
678 					  struct eap_fast_data *data)
679 {
680 	u8 pac_key[EAP_FAST_PAC_KEY_LEN];
681 	u8 *pac_buf, *pac_opaque;
682 	struct wpabuf *buf;
683 	u8 *pos;
684 	size_t buf_len, srv_id_info_len, pac_len;
685 	struct eap_tlv_hdr *pac_tlv;
686 	struct pac_tlv_hdr *pac_info;
687 	struct eap_tlv_result_tlv *result;
688 	struct os_time now;
689 
690 	if (random_get_bytes(pac_key, EAP_FAST_PAC_KEY_LEN) < 0 ||
691 	    os_get_time(&now) < 0)
692 		return NULL;
693 	wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: Generated PAC-Key",
694 			pac_key, EAP_FAST_PAC_KEY_LEN);
695 
696 	pac_len = (2 + EAP_FAST_PAC_KEY_LEN) + (2 + 4) +
697 		(2 + sm->identity_len) + 8;
698 	pac_buf = os_malloc(pac_len);
699 	if (pac_buf == NULL)
700 		return NULL;
701 
702 	srv_id_info_len = os_strlen(data->srv_id_info);
703 
704 	pos = pac_buf;
705 	*pos++ = PAC_OPAQUE_TYPE_KEY;
706 	*pos++ = EAP_FAST_PAC_KEY_LEN;
707 	os_memcpy(pos, pac_key, EAP_FAST_PAC_KEY_LEN);
708 	pos += EAP_FAST_PAC_KEY_LEN;
709 
710 	*pos++ = PAC_OPAQUE_TYPE_LIFETIME;
711 	*pos++ = 4;
712 	WPA_PUT_BE32(pos, now.sec + data->pac_key_lifetime);
713 	pos += 4;
714 
715 	if (sm->identity) {
716 		*pos++ = PAC_OPAQUE_TYPE_IDENTITY;
717 		*pos++ = sm->identity_len;
718 		os_memcpy(pos, sm->identity, sm->identity_len);
719 		pos += sm->identity_len;
720 	}
721 
722 	pac_len = pos - pac_buf;
723 	while (pac_len % 8) {
724 		*pos++ = PAC_OPAQUE_TYPE_PAD;
725 		pac_len++;
726 	}
727 
728 	pac_opaque = os_malloc(pac_len + 8);
729 	if (pac_opaque == NULL) {
730 		os_free(pac_buf);
731 		return NULL;
732 	}
733 	if (aes_wrap(data->pac_opaque_encr, sizeof(data->pac_opaque_encr),
734 		     pac_len / 8, pac_buf, pac_opaque) < 0) {
735 		os_free(pac_buf);
736 		os_free(pac_opaque);
737 		return NULL;
738 	}
739 	os_free(pac_buf);
740 
741 	pac_len += 8;
742 	wpa_hexdump(MSG_DEBUG, "EAP-FAST: PAC-Opaque",
743 		    pac_opaque, pac_len);
744 
745 	buf_len = sizeof(*pac_tlv) +
746 		sizeof(struct pac_tlv_hdr) + EAP_FAST_PAC_KEY_LEN +
747 		sizeof(struct pac_tlv_hdr) + pac_len +
748 		data->srv_id_len + srv_id_info_len + 100 + sizeof(*result);
749 	buf = wpabuf_alloc(buf_len);
750 	if (buf == NULL) {
751 		os_free(pac_opaque);
752 		return NULL;
753 	}
754 
755 	/* Result TLV */
756 	wpa_printf(MSG_DEBUG, "EAP-FAST: Add Result TLV (status=SUCCESS)");
757 	result = wpabuf_put(buf, sizeof(*result));
758 	WPA_PUT_BE16((u8 *) &result->tlv_type,
759 		     EAP_TLV_TYPE_MANDATORY | EAP_TLV_RESULT_TLV);
760 	WPA_PUT_BE16((u8 *) &result->length, 2);
761 	WPA_PUT_BE16((u8 *) &result->status, EAP_TLV_RESULT_SUCCESS);
762 
763 	/* PAC TLV */
764 	wpa_printf(MSG_DEBUG, "EAP-FAST: Add PAC TLV");
765 	pac_tlv = wpabuf_put(buf, sizeof(*pac_tlv));
766 	pac_tlv->tlv_type = host_to_be16(EAP_TLV_TYPE_MANDATORY |
767 					 EAP_TLV_PAC_TLV);
768 
769 	/* PAC-Key */
770 	eap_fast_put_tlv(buf, PAC_TYPE_PAC_KEY, pac_key, EAP_FAST_PAC_KEY_LEN);
771 
772 	/* PAC-Opaque */
773 	eap_fast_put_tlv(buf, PAC_TYPE_PAC_OPAQUE, pac_opaque, pac_len);
774 	os_free(pac_opaque);
775 
776 	/* PAC-Info */
777 	pac_info = wpabuf_put(buf, sizeof(*pac_info));
778 	pac_info->type = host_to_be16(PAC_TYPE_PAC_INFO);
779 
780 	/* PAC-Lifetime (inside PAC-Info) */
781 	eap_fast_put_tlv_hdr(buf, PAC_TYPE_CRED_LIFETIME, 4);
782 	wpabuf_put_be32(buf, now.sec + data->pac_key_lifetime);
783 
784 	/* A-ID (inside PAC-Info) */
785 	eap_fast_put_tlv(buf, PAC_TYPE_A_ID, data->srv_id, data->srv_id_len);
786 
787 	/* Note: headers may be misaligned after A-ID */
788 
789 	if (sm->identity) {
790 		eap_fast_put_tlv(buf, PAC_TYPE_I_ID, sm->identity,
791 				 sm->identity_len);
792 	}
793 
794 	/* A-ID-Info (inside PAC-Info) */
795 	eap_fast_put_tlv(buf, PAC_TYPE_A_ID_INFO, data->srv_id_info,
796 			 srv_id_info_len);
797 
798 	/* PAC-Type (inside PAC-Info) */
799 	eap_fast_put_tlv_hdr(buf, PAC_TYPE_PAC_TYPE, 2);
800 	wpabuf_put_be16(buf, PAC_TYPE_TUNNEL_PAC);
801 
802 	/* Update PAC-Info and PAC TLV Length fields */
803 	pos = wpabuf_put(buf, 0);
804 	pac_info->len = host_to_be16(pos - (u8 *) (pac_info + 1));
805 	pac_tlv->length = host_to_be16(pos - (u8 *) (pac_tlv + 1));
806 
807 	return buf;
808 }
809 
810 
eap_fast_encrypt_phase2(struct eap_sm * sm,struct eap_fast_data * data,struct wpabuf * plain,int piggyback)811 static int eap_fast_encrypt_phase2(struct eap_sm *sm,
812 				   struct eap_fast_data *data,
813 				   struct wpabuf *plain, int piggyback)
814 {
815 	struct wpabuf *encr;
816 
817 	wpa_hexdump_buf_key(MSG_DEBUG, "EAP-FAST: Encrypting Phase 2 TLVs",
818 			    plain);
819 	encr = eap_server_tls_encrypt(sm, &data->ssl, plain);
820 	wpabuf_free(plain);
821 
822 	if (!encr)
823 		return -1;
824 
825 	if (data->ssl.tls_out && piggyback) {
826 		wpa_printf(MSG_DEBUG, "EAP-FAST: Piggyback Phase 2 data "
827 			   "(len=%d) with last Phase 1 Message (len=%d "
828 			   "used=%d)",
829 			   (int) wpabuf_len(encr),
830 			   (int) wpabuf_len(data->ssl.tls_out),
831 			   (int) data->ssl.tls_out_pos);
832 		if (wpabuf_resize(&data->ssl.tls_out, wpabuf_len(encr)) < 0) {
833 			wpa_printf(MSG_WARNING, "EAP-FAST: Failed to resize "
834 				   "output buffer");
835 			wpabuf_free(encr);
836 			return -1;
837 		}
838 		wpabuf_put_buf(data->ssl.tls_out, encr);
839 		wpabuf_free(encr);
840 	} else {
841 		wpabuf_free(data->ssl.tls_out);
842 		data->ssl.tls_out_pos = 0;
843 		data->ssl.tls_out = encr;
844 	}
845 
846 	return 0;
847 }
848 
849 
eap_fast_buildReq(struct eap_sm * sm,void * priv,u8 id)850 static struct wpabuf * eap_fast_buildReq(struct eap_sm *sm, void *priv, u8 id)
851 {
852 	struct eap_fast_data *data = priv;
853 	struct wpabuf *req = NULL;
854 	int piggyback = 0;
855 
856 	if (data->ssl.state == FRAG_ACK) {
857 		return eap_server_tls_build_ack(id, EAP_TYPE_FAST,
858 						data->fast_version);
859 	}
860 
861 	if (data->ssl.state == WAIT_FRAG_ACK) {
862 		return eap_server_tls_build_msg(&data->ssl, EAP_TYPE_FAST,
863 						data->fast_version, id);
864 	}
865 
866 	switch (data->state) {
867 	case START:
868 		return eap_fast_build_start(sm, data, id);
869 	case PHASE1:
870 		if (tls_connection_established(sm->ssl_ctx, data->ssl.conn)) {
871 			if (eap_fast_phase1_done(sm, data) < 0)
872 				return NULL;
873 			if (data->state == PHASE2_START) {
874 				/*
875 				 * Try to generate Phase 2 data to piggyback
876 				 * with the end of Phase 1 to avoid extra
877 				 * roundtrip.
878 				 */
879 				wpa_printf(MSG_DEBUG, "EAP-FAST: Try to start "
880 					   "Phase 2");
881 				if (eap_fast_process_phase2_start(sm, data))
882 					break;
883 				req = eap_fast_build_phase2_req(sm, data, id);
884 				piggyback = 1;
885 			}
886 		}
887 		break;
888 	case PHASE2_ID:
889 	case PHASE2_METHOD:
890 		req = eap_fast_build_phase2_req(sm, data, id);
891 		break;
892 	case CRYPTO_BINDING:
893 		req = eap_fast_build_crypto_binding(sm, data);
894 		if (data->phase2_method) {
895 			/*
896 			 * Include the start of the next EAP method in the
897 			 * sequence in the same message with Crypto-Binding to
898 			 * save a round-trip.
899 			 */
900 			struct wpabuf *eap;
901 			eap = eap_fast_build_phase2_req(sm, data, id);
902 			req = wpabuf_concat(req, eap);
903 			eap_fast_state(data, PHASE2_METHOD);
904 		}
905 		break;
906 	case REQUEST_PAC:
907 		req = eap_fast_build_pac(sm, data);
908 		break;
909 	default:
910 		wpa_printf(MSG_DEBUG, "EAP-FAST: %s - unexpected state %d",
911 			   __func__, data->state);
912 		return NULL;
913 	}
914 
915 	if (req &&
916 	    eap_fast_encrypt_phase2(sm, data, req, piggyback) < 0)
917 		return NULL;
918 
919 	return eap_server_tls_build_msg(&data->ssl, EAP_TYPE_FAST,
920 					data->fast_version, id);
921 }
922 
923 
eap_fast_check(struct eap_sm * sm,void * priv,struct wpabuf * respData)924 static Boolean eap_fast_check(struct eap_sm *sm, void *priv,
925 			      struct wpabuf *respData)
926 {
927 	const u8 *pos;
928 	size_t len;
929 
930 	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_FAST, respData, &len);
931 	if (pos == NULL || len < 1) {
932 		wpa_printf(MSG_INFO, "EAP-FAST: Invalid frame");
933 		return TRUE;
934 	}
935 
936 	return FALSE;
937 }
938 
939 
eap_fast_phase2_init(struct eap_sm * sm,struct eap_fast_data * data,EapType eap_type)940 static int eap_fast_phase2_init(struct eap_sm *sm, struct eap_fast_data *data,
941 				EapType eap_type)
942 {
943 	if (data->phase2_priv && data->phase2_method) {
944 		data->phase2_method->reset(sm, data->phase2_priv);
945 		data->phase2_method = NULL;
946 		data->phase2_priv = NULL;
947 	}
948 	data->phase2_method = eap_server_get_eap_method(EAP_VENDOR_IETF,
949 							eap_type);
950 	if (!data->phase2_method)
951 		return -1;
952 
953 	if (data->key_block_p) {
954 		sm->auth_challenge = data->key_block_p->server_challenge;
955 		sm->peer_challenge = data->key_block_p->client_challenge;
956 	}
957 	sm->init_phase2 = 1;
958 	data->phase2_priv = data->phase2_method->init(sm);
959 	sm->init_phase2 = 0;
960 	sm->auth_challenge = NULL;
961 	sm->peer_challenge = NULL;
962 
963 	return data->phase2_priv == NULL ? -1 : 0;
964 }
965 
966 
eap_fast_process_phase2_response(struct eap_sm * sm,struct eap_fast_data * data,u8 * in_data,size_t in_len)967 static void eap_fast_process_phase2_response(struct eap_sm *sm,
968 					     struct eap_fast_data *data,
969 					     u8 *in_data, size_t in_len)
970 {
971 	u8 next_type = EAP_TYPE_NONE;
972 	struct eap_hdr *hdr;
973 	u8 *pos;
974 	size_t left;
975 	struct wpabuf buf;
976 	const struct eap_method *m = data->phase2_method;
977 	void *priv = data->phase2_priv;
978 
979 	if (priv == NULL) {
980 		wpa_printf(MSG_DEBUG, "EAP-FAST: %s - Phase2 not "
981 			   "initialized?!", __func__);
982 		return;
983 	}
984 
985 	hdr = (struct eap_hdr *) in_data;
986 	pos = (u8 *) (hdr + 1);
987 
988 	if (in_len > sizeof(*hdr) && *pos == EAP_TYPE_NAK) {
989 		left = in_len - sizeof(*hdr);
990 		wpa_hexdump(MSG_DEBUG, "EAP-FAST: Phase2 type Nak'ed; "
991 			    "allowed types", pos + 1, left - 1);
992 #ifdef EAP_SERVER_TNC
993 		if (m && m->vendor == EAP_VENDOR_IETF &&
994 		    m->method == EAP_TYPE_TNC) {
995 			wpa_printf(MSG_DEBUG, "EAP-FAST: Peer Nak'ed required "
996 				   "TNC negotiation");
997 			next_type = eap_fast_req_failure(sm, data);
998 			eap_fast_phase2_init(sm, data, next_type);
999 			return;
1000 		}
1001 #endif /* EAP_SERVER_TNC */
1002 		eap_sm_process_nak(sm, pos + 1, left - 1);
1003 		if (sm->user && sm->user_eap_method_index < EAP_MAX_METHODS &&
1004 		    sm->user->methods[sm->user_eap_method_index].method !=
1005 		    EAP_TYPE_NONE) {
1006 			next_type = sm->user->methods[
1007 				sm->user_eap_method_index++].method;
1008 			wpa_printf(MSG_DEBUG, "EAP-FAST: try EAP type %d",
1009 				   next_type);
1010 		} else {
1011 			next_type = eap_fast_req_failure(sm, data);
1012 		}
1013 		eap_fast_phase2_init(sm, data, next_type);
1014 		return;
1015 	}
1016 
1017 	wpabuf_set(&buf, in_data, in_len);
1018 
1019 	if (m->check(sm, priv, &buf)) {
1020 		wpa_printf(MSG_DEBUG, "EAP-FAST: Phase2 check() asked to "
1021 			   "ignore the packet");
1022 		eap_fast_req_failure(sm, data);
1023 		return;
1024 	}
1025 
1026 	m->process(sm, priv, &buf);
1027 
1028 	if (!m->isDone(sm, priv))
1029 		return;
1030 
1031 	if (!m->isSuccess(sm, priv)) {
1032 		wpa_printf(MSG_DEBUG, "EAP-FAST: Phase2 method failed");
1033 		next_type = eap_fast_req_failure(sm, data);
1034 		eap_fast_phase2_init(sm, data, next_type);
1035 		return;
1036 	}
1037 
1038 	switch (data->state) {
1039 	case PHASE2_ID:
1040 		if (eap_user_get(sm, sm->identity, sm->identity_len, 1) != 0) {
1041 			wpa_hexdump_ascii(MSG_DEBUG, "EAP-FAST: Phase2 "
1042 					  "Identity not found in the user "
1043 					  "database",
1044 					  sm->identity, sm->identity_len);
1045 			next_type = eap_fast_req_failure(sm, data);
1046 			break;
1047 		}
1048 
1049 		eap_fast_state(data, PHASE2_METHOD);
1050 		if (data->anon_provisioning) {
1051 			/*
1052 			 * Only EAP-MSCHAPv2 is allowed for anonymous
1053 			 * provisioning.
1054 			 */
1055 			next_type = EAP_TYPE_MSCHAPV2;
1056 			sm->user_eap_method_index = 0;
1057 		} else {
1058 			next_type = sm->user->methods[0].method;
1059 			sm->user_eap_method_index = 1;
1060 		}
1061 		wpa_printf(MSG_DEBUG, "EAP-FAST: try EAP type %d", next_type);
1062 		break;
1063 	case PHASE2_METHOD:
1064 	case CRYPTO_BINDING:
1065 		eap_fast_update_icmk(sm, data);
1066 		eap_fast_state(data, CRYPTO_BINDING);
1067 		data->eap_seq++;
1068 		next_type = EAP_TYPE_NONE;
1069 #ifdef EAP_SERVER_TNC
1070 		if (sm->tnc && !data->tnc_started) {
1071 			wpa_printf(MSG_DEBUG, "EAP-FAST: Initialize TNC");
1072 			next_type = EAP_TYPE_TNC;
1073 			data->tnc_started = 1;
1074 		}
1075 #endif /* EAP_SERVER_TNC */
1076 		break;
1077 	case FAILURE:
1078 		break;
1079 	default:
1080 		wpa_printf(MSG_DEBUG, "EAP-FAST: %s - unexpected state %d",
1081 			   __func__, data->state);
1082 		break;
1083 	}
1084 
1085 	eap_fast_phase2_init(sm, data, next_type);
1086 }
1087 
1088 
eap_fast_process_phase2_eap(struct eap_sm * sm,struct eap_fast_data * data,u8 * in_data,size_t in_len)1089 static void eap_fast_process_phase2_eap(struct eap_sm *sm,
1090 					struct eap_fast_data *data,
1091 					u8 *in_data, size_t in_len)
1092 {
1093 	struct eap_hdr *hdr;
1094 	size_t len;
1095 
1096 	hdr = (struct eap_hdr *) in_data;
1097 	if (in_len < (int) sizeof(*hdr)) {
1098 		wpa_printf(MSG_INFO, "EAP-FAST: Too short Phase 2 "
1099 			   "EAP frame (len=%lu)", (unsigned long) in_len);
1100 		eap_fast_req_failure(sm, data);
1101 		return;
1102 	}
1103 	len = be_to_host16(hdr->length);
1104 	if (len > in_len) {
1105 		wpa_printf(MSG_INFO, "EAP-FAST: Length mismatch in "
1106 			   "Phase 2 EAP frame (len=%lu hdr->length=%lu)",
1107 			   (unsigned long) in_len, (unsigned long) len);
1108 		eap_fast_req_failure(sm, data);
1109 		return;
1110 	}
1111 	wpa_printf(MSG_DEBUG, "EAP-FAST: Received Phase 2: code=%d "
1112 		   "identifier=%d length=%lu", hdr->code, hdr->identifier,
1113 		   (unsigned long) len);
1114 	switch (hdr->code) {
1115 	case EAP_CODE_RESPONSE:
1116 		eap_fast_process_phase2_response(sm, data, (u8 *) hdr, len);
1117 		break;
1118 	default:
1119 		wpa_printf(MSG_INFO, "EAP-FAST: Unexpected code=%d in "
1120 			   "Phase 2 EAP header", hdr->code);
1121 		break;
1122 	}
1123 }
1124 
1125 
eap_fast_parse_tlvs(struct wpabuf * data,struct eap_fast_tlv_parse * tlv)1126 static int eap_fast_parse_tlvs(struct wpabuf *data,
1127 			       struct eap_fast_tlv_parse *tlv)
1128 {
1129 	int mandatory, tlv_type, res;
1130 	size_t len;
1131 	u8 *pos, *end;
1132 
1133 	os_memset(tlv, 0, sizeof(*tlv));
1134 
1135 	pos = wpabuf_mhead(data);
1136 	end = pos + wpabuf_len(data);
1137 	while (pos + 4 < end) {
1138 		mandatory = pos[0] & 0x80;
1139 		tlv_type = WPA_GET_BE16(pos) & 0x3fff;
1140 		pos += 2;
1141 		len = WPA_GET_BE16(pos);
1142 		pos += 2;
1143 		if (len > (size_t) (end - pos)) {
1144 			wpa_printf(MSG_INFO, "EAP-FAST: TLV overflow");
1145 			return -1;
1146 		}
1147 		wpa_printf(MSG_DEBUG, "EAP-FAST: Received Phase 2: "
1148 			   "TLV type %d length %u%s",
1149 			   tlv_type, (unsigned int) len,
1150 			   mandatory ? " (mandatory)" : "");
1151 
1152 		res = eap_fast_parse_tlv(tlv, tlv_type, pos, len);
1153 		if (res == -2)
1154 			break;
1155 		if (res < 0) {
1156 			if (mandatory) {
1157 				wpa_printf(MSG_DEBUG, "EAP-FAST: Nak unknown "
1158 					   "mandatory TLV type %d", tlv_type);
1159 				/* TODO: generate Nak TLV */
1160 				break;
1161 			} else {
1162 				wpa_printf(MSG_DEBUG, "EAP-FAST: Ignored "
1163 					   "unknown optional TLV type %d",
1164 					   tlv_type);
1165 			}
1166 		}
1167 
1168 		pos += len;
1169 	}
1170 
1171 	return 0;
1172 }
1173 
1174 
eap_fast_validate_crypto_binding(struct eap_fast_data * data,struct eap_tlv_crypto_binding_tlv * b,size_t bind_len)1175 static int eap_fast_validate_crypto_binding(
1176 	struct eap_fast_data *data, struct eap_tlv_crypto_binding_tlv *b,
1177 	size_t bind_len)
1178 {
1179 	u8 cmac[SHA1_MAC_LEN];
1180 
1181 	wpa_printf(MSG_DEBUG, "EAP-FAST: Reply Crypto-Binding TLV: "
1182 		   "Version %d Received Version %d SubType %d",
1183 		   b->version, b->received_version, b->subtype);
1184 	wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: NONCE",
1185 		    b->nonce, sizeof(b->nonce));
1186 	wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: Compound MAC",
1187 		    b->compound_mac, sizeof(b->compound_mac));
1188 
1189 	if (b->version != EAP_FAST_VERSION ||
1190 	    b->received_version != EAP_FAST_VERSION) {
1191 		wpa_printf(MSG_DEBUG, "EAP-FAST: Unexpected version "
1192 			   "in Crypto-Binding: version %d "
1193 			   "received_version %d", b->version,
1194 			   b->received_version);
1195 		return -1;
1196 	}
1197 
1198 	if (b->subtype != EAP_TLV_CRYPTO_BINDING_SUBTYPE_RESPONSE) {
1199 		wpa_printf(MSG_DEBUG, "EAP-FAST: Unexpected subtype in "
1200 			   "Crypto-Binding: %d", b->subtype);
1201 		return -1;
1202 	}
1203 
1204 	if (os_memcmp_const(data->crypto_binding_nonce, b->nonce, 31) != 0 ||
1205 	    (data->crypto_binding_nonce[31] | 1) != b->nonce[31]) {
1206 		wpa_printf(MSG_DEBUG, "EAP-FAST: Invalid nonce in "
1207 			   "Crypto-Binding");
1208 		return -1;
1209 	}
1210 
1211 	os_memcpy(cmac, b->compound_mac, sizeof(cmac));
1212 	os_memset(b->compound_mac, 0, sizeof(cmac));
1213 	wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: Crypto-Binding TLV for "
1214 		    "Compound MAC calculation",
1215 		    (u8 *) b, bind_len);
1216 	hmac_sha1(data->cmk, EAP_FAST_CMK_LEN, (u8 *) b, bind_len,
1217 		  b->compound_mac);
1218 	if (os_memcmp_const(cmac, b->compound_mac, sizeof(cmac)) != 0) {
1219 		wpa_hexdump(MSG_MSGDUMP,
1220 			    "EAP-FAST: Calculated Compound MAC",
1221 			    b->compound_mac, sizeof(cmac));
1222 		wpa_printf(MSG_INFO, "EAP-FAST: Compound MAC did not "
1223 			   "match");
1224 		return -1;
1225 	}
1226 
1227 	return 0;
1228 }
1229 
1230 
eap_fast_pac_type(u8 * pac,size_t len,u16 type)1231 static int eap_fast_pac_type(u8 *pac, size_t len, u16 type)
1232 {
1233 	struct eap_tlv_pac_type_tlv *tlv;
1234 
1235 	if (pac == NULL || len != sizeof(*tlv))
1236 		return 0;
1237 
1238 	tlv = (struct eap_tlv_pac_type_tlv *) pac;
1239 
1240 	return be_to_host16(tlv->tlv_type) == PAC_TYPE_PAC_TYPE &&
1241 		be_to_host16(tlv->length) == 2 &&
1242 		be_to_host16(tlv->pac_type) == type;
1243 }
1244 
1245 
eap_fast_process_phase2_tlvs(struct eap_sm * sm,struct eap_fast_data * data,struct wpabuf * in_data)1246 static void eap_fast_process_phase2_tlvs(struct eap_sm *sm,
1247 					 struct eap_fast_data *data,
1248 					 struct wpabuf *in_data)
1249 {
1250 	struct eap_fast_tlv_parse tlv;
1251 	int check_crypto_binding = data->state == CRYPTO_BINDING;
1252 
1253 	if (eap_fast_parse_tlvs(in_data, &tlv) < 0) {
1254 		wpa_printf(MSG_DEBUG, "EAP-FAST: Failed to parse received "
1255 			   "Phase 2 TLVs");
1256 		return;
1257 	}
1258 
1259 	if (tlv.result == EAP_TLV_RESULT_FAILURE) {
1260 		wpa_printf(MSG_DEBUG, "EAP-FAST: Result TLV indicated "
1261 			   "failure");
1262 		eap_fast_state(data, FAILURE);
1263 		return;
1264 	}
1265 
1266 	if (data->state == REQUEST_PAC) {
1267 		u16 type, len, res;
1268 		if (tlv.pac == NULL || tlv.pac_len < 6) {
1269 			wpa_printf(MSG_DEBUG, "EAP-FAST: No PAC "
1270 				   "Acknowledgement received");
1271 			eap_fast_state(data, FAILURE);
1272 			return;
1273 		}
1274 
1275 		type = WPA_GET_BE16(tlv.pac);
1276 		len = WPA_GET_BE16(tlv.pac + 2);
1277 		res = WPA_GET_BE16(tlv.pac + 4);
1278 
1279 		if (type != PAC_TYPE_PAC_ACKNOWLEDGEMENT || len != 2 ||
1280 		    res != EAP_TLV_RESULT_SUCCESS) {
1281 			wpa_printf(MSG_DEBUG, "EAP-FAST: PAC TLV did not "
1282 				   "contain acknowledgement");
1283 			eap_fast_state(data, FAILURE);
1284 			return;
1285 		}
1286 
1287 		wpa_printf(MSG_DEBUG, "EAP-FAST: PAC-Acknowledgement received "
1288 			   "- PAC provisioning succeeded");
1289 		eap_fast_state(data, (data->anon_provisioning ||
1290 				      data->send_new_pac == 2) ?
1291 			       FAILURE : SUCCESS);
1292 		return;
1293 	}
1294 
1295 	if (check_crypto_binding) {
1296 		if (tlv.crypto_binding == NULL) {
1297 			wpa_printf(MSG_DEBUG, "EAP-FAST: No Crypto-Binding "
1298 				   "TLV received");
1299 			eap_fast_state(data, FAILURE);
1300 			return;
1301 		}
1302 
1303 		if (data->final_result &&
1304 		    tlv.result != EAP_TLV_RESULT_SUCCESS) {
1305 			wpa_printf(MSG_DEBUG, "EAP-FAST: Crypto-Binding TLV "
1306 				   "without Success Result");
1307 			eap_fast_state(data, FAILURE);
1308 			return;
1309 		}
1310 
1311 		if (!data->final_result &&
1312 		    tlv.iresult != EAP_TLV_RESULT_SUCCESS) {
1313 			wpa_printf(MSG_DEBUG, "EAP-FAST: Crypto-Binding TLV "
1314 				   "without intermediate Success Result");
1315 			eap_fast_state(data, FAILURE);
1316 			return;
1317 		}
1318 
1319 		if (eap_fast_validate_crypto_binding(data, tlv.crypto_binding,
1320 						     tlv.crypto_binding_len)) {
1321 			eap_fast_state(data, FAILURE);
1322 			return;
1323 		}
1324 
1325 		wpa_printf(MSG_DEBUG, "EAP-FAST: Valid Crypto-Binding TLV "
1326 			   "received");
1327 		if (data->final_result) {
1328 			wpa_printf(MSG_DEBUG, "EAP-FAST: Authentication "
1329 				   "completed successfully");
1330 		}
1331 
1332 		if (data->anon_provisioning &&
1333 		    sm->eap_fast_prov != ANON_PROV &&
1334 		    sm->eap_fast_prov != BOTH_PROV) {
1335 			wpa_printf(MSG_DEBUG, "EAP-FAST: Client is trying to "
1336 				   "use unauthenticated provisioning which is "
1337 				   "disabled");
1338 			eap_fast_state(data, FAILURE);
1339 			return;
1340 		}
1341 
1342 		if (sm->eap_fast_prov != AUTH_PROV &&
1343 		    sm->eap_fast_prov != BOTH_PROV &&
1344 		    tlv.request_action == EAP_TLV_ACTION_PROCESS_TLV &&
1345 		    eap_fast_pac_type(tlv.pac, tlv.pac_len,
1346 				      PAC_TYPE_TUNNEL_PAC)) {
1347 			wpa_printf(MSG_DEBUG, "EAP-FAST: Client is trying to "
1348 				   "use authenticated provisioning which is "
1349 				   "disabled");
1350 			eap_fast_state(data, FAILURE);
1351 			return;
1352 		}
1353 
1354 		if (data->anon_provisioning ||
1355 		    (tlv.request_action == EAP_TLV_ACTION_PROCESS_TLV &&
1356 		     eap_fast_pac_type(tlv.pac, tlv.pac_len,
1357 				       PAC_TYPE_TUNNEL_PAC))) {
1358 			wpa_printf(MSG_DEBUG, "EAP-FAST: Requested a new "
1359 				   "Tunnel PAC");
1360 			eap_fast_state(data, REQUEST_PAC);
1361 		} else if (data->send_new_pac) {
1362 			wpa_printf(MSG_DEBUG, "EAP-FAST: Server triggered "
1363 				   "re-keying of Tunnel PAC");
1364 			eap_fast_state(data, REQUEST_PAC);
1365 		} else if (data->final_result)
1366 			eap_fast_state(data, SUCCESS);
1367 	}
1368 
1369 	if (tlv.eap_payload_tlv) {
1370 		eap_fast_process_phase2_eap(sm, data, tlv.eap_payload_tlv,
1371 					    tlv.eap_payload_tlv_len);
1372 	}
1373 }
1374 
1375 
eap_fast_process_phase2(struct eap_sm * sm,struct eap_fast_data * data,struct wpabuf * in_buf)1376 static void eap_fast_process_phase2(struct eap_sm *sm,
1377 				    struct eap_fast_data *data,
1378 				    struct wpabuf *in_buf)
1379 {
1380 	struct wpabuf *in_decrypted;
1381 
1382 	wpa_printf(MSG_DEBUG, "EAP-FAST: Received %lu bytes encrypted data for"
1383 		   " Phase 2", (unsigned long) wpabuf_len(in_buf));
1384 
1385 	if (data->pending_phase2_resp) {
1386 		wpa_printf(MSG_DEBUG, "EAP-PEAP: Pending Phase 2 response - "
1387 			   "skip decryption and use old data");
1388 		eap_fast_process_phase2_tlvs(sm, data,
1389 					     data->pending_phase2_resp);
1390 		wpabuf_free(data->pending_phase2_resp);
1391 		data->pending_phase2_resp = NULL;
1392 		return;
1393 	}
1394 
1395 	in_decrypted = tls_connection_decrypt(sm->ssl_ctx, data->ssl.conn,
1396 					      in_buf);
1397 	if (in_decrypted == NULL) {
1398 		wpa_printf(MSG_INFO, "EAP-FAST: Failed to decrypt Phase 2 "
1399 			   "data");
1400 		eap_fast_state(data, FAILURE);
1401 		return;
1402 	}
1403 
1404 	wpa_hexdump_buf_key(MSG_DEBUG, "EAP-FAST: Decrypted Phase 2 TLVs",
1405 			    in_decrypted);
1406 
1407 	eap_fast_process_phase2_tlvs(sm, data, in_decrypted);
1408 
1409 	if (sm->method_pending == METHOD_PENDING_WAIT) {
1410 		wpa_printf(MSG_DEBUG, "EAP-FAST: Phase2 method is in "
1411 			   "pending wait state - save decrypted response");
1412 		wpabuf_free(data->pending_phase2_resp);
1413 		data->pending_phase2_resp = in_decrypted;
1414 		return;
1415 	}
1416 
1417 	wpabuf_free(in_decrypted);
1418 }
1419 
1420 
eap_fast_process_version(struct eap_sm * sm,void * priv,int peer_version)1421 static int eap_fast_process_version(struct eap_sm *sm, void *priv,
1422 				    int peer_version)
1423 {
1424 	struct eap_fast_data *data = priv;
1425 
1426 	data->peer_version = peer_version;
1427 
1428 	if (data->force_version >= 0 && peer_version != data->force_version) {
1429 		wpa_printf(MSG_INFO, "EAP-FAST: peer did not select the forced"
1430 			   " version (forced=%d peer=%d) - reject",
1431 			   data->force_version, peer_version);
1432 		return -1;
1433 	}
1434 
1435 	if (peer_version < data->fast_version) {
1436 		wpa_printf(MSG_DEBUG, "EAP-FAST: peer ver=%d, own ver=%d; "
1437 			   "use version %d",
1438 			   peer_version, data->fast_version, peer_version);
1439 		data->fast_version = peer_version;
1440 	}
1441 
1442 	return 0;
1443 }
1444 
1445 
eap_fast_process_phase1(struct eap_sm * sm,struct eap_fast_data * data)1446 static int eap_fast_process_phase1(struct eap_sm *sm,
1447 				   struct eap_fast_data *data)
1448 {
1449 	if (eap_server_tls_phase1(sm, &data->ssl) < 0) {
1450 		wpa_printf(MSG_INFO, "EAP-FAST: TLS processing failed");
1451 		eap_fast_state(data, FAILURE);
1452 		return -1;
1453 	}
1454 
1455 	if (!tls_connection_established(sm->ssl_ctx, data->ssl.conn) ||
1456 	    wpabuf_len(data->ssl.tls_out) > 0)
1457 		return 1;
1458 
1459 	/*
1460 	 * Phase 1 was completed with the received message (e.g., when using
1461 	 * abbreviated handshake), so Phase 2 can be started immediately
1462 	 * without having to send through an empty message to the peer.
1463 	 */
1464 
1465 	return eap_fast_phase1_done(sm, data);
1466 }
1467 
1468 
eap_fast_process_phase2_start(struct eap_sm * sm,struct eap_fast_data * data)1469 static int eap_fast_process_phase2_start(struct eap_sm *sm,
1470 					 struct eap_fast_data *data)
1471 {
1472 	u8 next_type;
1473 
1474 	if (data->identity) {
1475 		os_free(sm->identity);
1476 		sm->identity = data->identity;
1477 		data->identity = NULL;
1478 		sm->identity_len = data->identity_len;
1479 		data->identity_len = 0;
1480 		sm->require_identity_match = 1;
1481 		if (eap_user_get(sm, sm->identity, sm->identity_len, 1) != 0) {
1482 			wpa_hexdump_ascii(MSG_DEBUG, "EAP-FAST: "
1483 					  "Phase2 Identity not found "
1484 					  "in the user database",
1485 					  sm->identity, sm->identity_len);
1486 			next_type = eap_fast_req_failure(sm, data);
1487 		} else {
1488 			wpa_printf(MSG_DEBUG, "EAP-FAST: Identity already "
1489 				   "known - skip Phase 2 Identity Request");
1490 			next_type = sm->user->methods[0].method;
1491 			sm->user_eap_method_index = 1;
1492 		}
1493 
1494 		eap_fast_state(data, PHASE2_METHOD);
1495 	} else {
1496 		eap_fast_state(data, PHASE2_ID);
1497 		next_type = EAP_TYPE_IDENTITY;
1498 	}
1499 
1500 	return eap_fast_phase2_init(sm, data, next_type);
1501 }
1502 
1503 
eap_fast_process_msg(struct eap_sm * sm,void * priv,const struct wpabuf * respData)1504 static void eap_fast_process_msg(struct eap_sm *sm, void *priv,
1505 				 const struct wpabuf *respData)
1506 {
1507 	struct eap_fast_data *data = priv;
1508 
1509 	switch (data->state) {
1510 	case PHASE1:
1511 		if (eap_fast_process_phase1(sm, data))
1512 			break;
1513 
1514 		/* fall through to PHASE2_START */
1515 	case PHASE2_START:
1516 		eap_fast_process_phase2_start(sm, data);
1517 		break;
1518 	case PHASE2_ID:
1519 	case PHASE2_METHOD:
1520 	case CRYPTO_BINDING:
1521 	case REQUEST_PAC:
1522 		eap_fast_process_phase2(sm, data, data->ssl.tls_in);
1523 		break;
1524 	default:
1525 		wpa_printf(MSG_DEBUG, "EAP-FAST: Unexpected state %d in %s",
1526 			   data->state, __func__);
1527 		break;
1528 	}
1529 }
1530 
1531 
eap_fast_process(struct eap_sm * sm,void * priv,struct wpabuf * respData)1532 static void eap_fast_process(struct eap_sm *sm, void *priv,
1533 			     struct wpabuf *respData)
1534 {
1535 	struct eap_fast_data *data = priv;
1536 	if (eap_server_tls_process(sm, &data->ssl, respData, data,
1537 				   EAP_TYPE_FAST, eap_fast_process_version,
1538 				   eap_fast_process_msg) < 0)
1539 		eap_fast_state(data, FAILURE);
1540 }
1541 
1542 
eap_fast_isDone(struct eap_sm * sm,void * priv)1543 static Boolean eap_fast_isDone(struct eap_sm *sm, void *priv)
1544 {
1545 	struct eap_fast_data *data = priv;
1546 	return data->state == SUCCESS || data->state == FAILURE;
1547 }
1548 
1549 
eap_fast_getKey(struct eap_sm * sm,void * priv,size_t * len)1550 static u8 * eap_fast_getKey(struct eap_sm *sm, void *priv, size_t *len)
1551 {
1552 	struct eap_fast_data *data = priv;
1553 	u8 *eapKeyData;
1554 
1555 	if (data->state != SUCCESS)
1556 		return NULL;
1557 
1558 	eapKeyData = os_malloc(EAP_FAST_KEY_LEN);
1559 	if (eapKeyData == NULL)
1560 		return NULL;
1561 
1562 	eap_fast_derive_eap_msk(data->simck, eapKeyData);
1563 	*len = EAP_FAST_KEY_LEN;
1564 
1565 	return eapKeyData;
1566 }
1567 
1568 
eap_fast_get_emsk(struct eap_sm * sm,void * priv,size_t * len)1569 static u8 * eap_fast_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
1570 {
1571 	struct eap_fast_data *data = priv;
1572 	u8 *eapKeyData;
1573 
1574 	if (data->state != SUCCESS)
1575 		return NULL;
1576 
1577 	eapKeyData = os_malloc(EAP_EMSK_LEN);
1578 	if (eapKeyData == NULL)
1579 		return NULL;
1580 
1581 	eap_fast_derive_eap_emsk(data->simck, eapKeyData);
1582 	*len = EAP_EMSK_LEN;
1583 
1584 	return eapKeyData;
1585 }
1586 
1587 
eap_fast_isSuccess(struct eap_sm * sm,void * priv)1588 static Boolean eap_fast_isSuccess(struct eap_sm *sm, void *priv)
1589 {
1590 	struct eap_fast_data *data = priv;
1591 	return data->state == SUCCESS;
1592 }
1593 
1594 
eap_fast_get_session_id(struct eap_sm * sm,void * priv,size_t * len)1595 static u8 * eap_fast_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
1596 {
1597 	struct eap_fast_data *data = priv;
1598 
1599 	if (data->state != SUCCESS)
1600 		return NULL;
1601 
1602 	return eap_server_tls_derive_session_id(sm, &data->ssl, EAP_TYPE_FAST,
1603 						len);
1604 }
1605 
1606 
eap_server_fast_register(void)1607 int eap_server_fast_register(void)
1608 {
1609 	struct eap_method *eap;
1610 	int ret;
1611 
1612 	eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
1613 				      EAP_VENDOR_IETF, EAP_TYPE_FAST, "FAST");
1614 	if (eap == NULL)
1615 		return -1;
1616 
1617 	eap->init = eap_fast_init;
1618 	eap->reset = eap_fast_reset;
1619 	eap->buildReq = eap_fast_buildReq;
1620 	eap->check = eap_fast_check;
1621 	eap->process = eap_fast_process;
1622 	eap->isDone = eap_fast_isDone;
1623 	eap->getKey = eap_fast_getKey;
1624 	eap->get_emsk = eap_fast_get_emsk;
1625 	eap->isSuccess = eap_fast_isSuccess;
1626 	eap->getSessionId = eap_fast_get_session_id;
1627 
1628 	ret = eap_server_method_register(eap);
1629 	if (ret)
1630 		eap_server_method_free(eap);
1631 	return ret;
1632 }
1633