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