1 /*
2  * EAP-FAST server (RFC 4851)
3  * Copyright (c) 2004-2008, Jouni Malinen <j@w1.fi>
4  *
5  * This software may be distributed under the terms of the BSD license.
6  * See README for more details.
7  */
8 
9 #include "includes.h"
10 
11 #include "common.h"
12 #include "crypto/aes_wrap.h"
13 #include "crypto/sha1.h"
14 #include "crypto/tls.h"
15 #include "crypto/random.h"
16 #include "eap_common/eap_tlv_common.h"
17 #include "eap_common/eap_fast_common.h"
18 #include "eap_i.h"
19 #include "eap_tls_common.h"
20 
21 
22 static void eap_fast_reset(struct eap_sm *sm, void *priv);
23 
24 
25 /* Private PAC-Opaque TLV types */
26 #define PAC_OPAQUE_TYPE_PAD 0
27 #define PAC_OPAQUE_TYPE_KEY 1
28 #define PAC_OPAQUE_TYPE_LIFETIME 2
29 #define PAC_OPAQUE_TYPE_IDENTITY 3
30 
31 struct eap_fast_data {
32 	struct eap_ssl_data ssl;
33 	enum {
34 		START, PHASE1, PHASE2_START, PHASE2_ID, PHASE2_METHOD,
35 		CRYPTO_BINDING, REQUEST_PAC, SUCCESS, FAILURE
36 	} state;
37 
38 	int fast_version;
39 	const struct eap_method *phase2_method;
40 	void *phase2_priv;
41 	int force_version;
42 	int peer_version;
43 
44 	u8 crypto_binding_nonce[32];
45 	int final_result;
46 
47 	struct eap_fast_key_block_provisioning *key_block_p;
48 
49 	u8 simck[EAP_FAST_SIMCK_LEN];
50 	u8 cmk[EAP_FAST_CMK_LEN];
51 	int simck_idx;
52 
53 	u8 pac_opaque_encr[16];
54 	u8 *srv_id;
55 	size_t srv_id_len;
56 	char *srv_id_info;
57 
58 	int anon_provisioning;
59 	int send_new_pac; /* server triggered re-keying of Tunnel PAC */
60 	struct wpabuf *pending_phase2_resp;
61 	u8 *identity; /* from PAC-Opaque */
62 	size_t identity_len;
63 	int eap_seq;
64 	int tnc_started;
65 
66 	int pac_key_lifetime;
67 	int pac_key_refresh_time;
68 };
69 
70 
71 static int eap_fast_process_phase2_start(struct eap_sm *sm,
72 					 struct eap_fast_data *data);
73 
74 
eap_fast_state_txt(int state)75 static const char * eap_fast_state_txt(int state)
76 {
77 	switch (state) {
78 	case START:
79 		return "START";
80 	case PHASE1:
81 		return "PHASE1";
82 	case PHASE2_START:
83 		return "PHASE2_START";
84 	case PHASE2_ID:
85 		return "PHASE2_ID";
86 	case PHASE2_METHOD:
87 		return "PHASE2_METHOD";
88 	case CRYPTO_BINDING:
89 		return "CRYPTO_BINDING";
90 	case REQUEST_PAC:
91 		return "REQUEST_PAC";
92 	case SUCCESS:
93 		return "SUCCESS";
94 	case FAILURE:
95 		return "FAILURE";
96 	default:
97 		return "Unknown?!";
98 	}
99 }
100 
101 
eap_fast_state(struct eap_fast_data * data,int state)102 static void eap_fast_state(struct eap_fast_data *data, int state)
103 {
104 	wpa_printf(MSG_DEBUG, "EAP-FAST: %s -> %s",
105 		   eap_fast_state_txt(data->state),
106 		   eap_fast_state_txt(state));
107 	data->state = state;
108 }
109 
110 
eap_fast_req_failure(struct eap_sm * sm,struct eap_fast_data * data)111 static enum eap_type eap_fast_req_failure(struct eap_sm *sm,
112 					  struct eap_fast_data *data)
113 {
114 	/* TODO: send Result TLV(FAILURE) */
115 	eap_fast_state(data, FAILURE);
116 	return EAP_TYPE_NONE;
117 }
118 
119 
eap_fast_session_ticket_cb(void * ctx,const u8 * ticket,size_t len,const u8 * client_random,const u8 * server_random,u8 * master_secret)120 static int eap_fast_session_ticket_cb(void *ctx, const u8 *ticket, size_t len,
121 				      const u8 *client_random,
122 				      const u8 *server_random,
123 				      u8 *master_secret)
124 {
125 	struct eap_fast_data *data = ctx;
126 	const u8 *pac_opaque;
127 	size_t pac_opaque_len;
128 	u8 *buf, *pos, *end, *pac_key = NULL;
129 	os_time_t lifetime = 0;
130 	struct os_time now;
131 	u8 *identity = NULL;
132 	size_t identity_len = 0;
133 
134 	wpa_printf(MSG_DEBUG, "EAP-FAST: SessionTicket callback");
135 	wpa_hexdump(MSG_DEBUG, "EAP-FAST: SessionTicket (PAC-Opaque)",
136 		    ticket, len);
137 
138 	if (len < 4 || WPA_GET_BE16(ticket) != PAC_TYPE_PAC_OPAQUE) {
139 		wpa_printf(MSG_DEBUG, "EAP-FAST: Ignore invalid "
140 			   "SessionTicket");
141 		return 0;
142 	}
143 
144 	pac_opaque_len = WPA_GET_BE16(ticket + 2);
145 	pac_opaque = ticket + 4;
146 	if (pac_opaque_len < 8 || pac_opaque_len % 8 ||
147 	    pac_opaque_len > len - 4) {
148 		wpa_printf(MSG_DEBUG, "EAP-FAST: Ignore invalid PAC-Opaque "
149 			   "(len=%lu left=%lu)",
150 			   (unsigned long) pac_opaque_len,
151 			   (unsigned long) len);
152 		return 0;
153 	}
154 	wpa_hexdump(MSG_DEBUG, "EAP-FAST: Received PAC-Opaque",
155 		    pac_opaque, pac_opaque_len);
156 
157 	buf = os_malloc(pac_opaque_len - 8);
158 	if (buf == NULL) {
159 		wpa_printf(MSG_DEBUG, "EAP-FAST: Failed to allocate memory "
160 			   "for decrypting PAC-Opaque");
161 		return 0;
162 	}
163 
164 	if (aes_unwrap(data->pac_opaque_encr, sizeof(data->pac_opaque_encr),
165 		       (pac_opaque_len - 8) / 8, pac_opaque, buf) < 0) {
166 		wpa_printf(MSG_DEBUG, "EAP-FAST: Failed to decrypt "
167 			   "PAC-Opaque");
168 		os_free(buf);
169 		/*
170 		 * This may have been caused by server changing the PAC-Opaque
171 		 * encryption key, so just ignore this PAC-Opaque instead of
172 		 * failing the authentication completely. Provisioning can now
173 		 * be used to provision a new PAC.
174 		 */
175 		return 0;
176 	}
177 
178 	end = buf + pac_opaque_len - 8;
179 	wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: Decrypted PAC-Opaque",
180 			buf, end - buf);
181 
182 	pos = buf;
183 	while (end - pos > 1) {
184 		u8 id, elen;
185 
186 		id = *pos++;
187 		elen = *pos++;
188 		if (elen > end - pos)
189 			break;
190 
191 		switch (id) {
192 		case PAC_OPAQUE_TYPE_PAD:
193 			goto done;
194 		case PAC_OPAQUE_TYPE_KEY:
195 			if (elen != EAP_FAST_PAC_KEY_LEN) {
196 				wpa_printf(MSG_DEBUG,
197 					   "EAP-FAST: Invalid PAC-Key length %d",
198 					   elen);
199 				os_free(buf);
200 				return -1;
201 			}
202 			pac_key = pos;
203 			wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: PAC-Key from "
204 					"decrypted PAC-Opaque",
205 					pac_key, EAP_FAST_PAC_KEY_LEN);
206 			break;
207 		case PAC_OPAQUE_TYPE_LIFETIME:
208 			if (elen != 4) {
209 				wpa_printf(MSG_DEBUG, "EAP-FAST: Invalid "
210 					   "PAC-Key lifetime length %d",
211 					   elen);
212 				os_free(buf);
213 				return -1;
214 			}
215 			lifetime = WPA_GET_BE32(pos);
216 			break;
217 		case PAC_OPAQUE_TYPE_IDENTITY:
218 			identity = pos;
219 			identity_len = elen;
220 			break;
221 		}
222 
223 		pos += elen;
224 	}
225 done:
226 
227 	if (pac_key == NULL) {
228 		wpa_printf(MSG_DEBUG, "EAP-FAST: No PAC-Key included in "
229 			   "PAC-Opaque");
230 		os_free(buf);
231 		return -1;
232 	}
233 
234 	if (identity) {
235 		wpa_hexdump_ascii(MSG_DEBUG, "EAP-FAST: Identity from "
236 				  "PAC-Opaque", identity, identity_len);
237 		os_free(data->identity);
238 		data->identity = os_malloc(identity_len);
239 		if (data->identity) {
240 			os_memcpy(data->identity, identity, identity_len);
241 			data->identity_len = identity_len;
242 		}
243 	}
244 
245 	if (os_get_time(&now) < 0 || lifetime <= 0 || now.sec > lifetime) {
246 		wpa_printf(MSG_DEBUG, "EAP-FAST: PAC-Key not valid anymore "
247 			   "(lifetime=%ld now=%ld)", lifetime, now.sec);
248 		data->send_new_pac = 2;
249 		/*
250 		 * Allow PAC to be used to allow a PAC update with some level
251 		 * of server authentication (i.e., do not fall back to full TLS
252 		 * handshake since we cannot be sure that the peer would be
253 		 * able to validate server certificate now). However, reject
254 		 * the authentication since the PAC was not valid anymore. Peer
255 		 * can connect again with the newly provisioned PAC after this.
256 		 */
257 	} else if (lifetime - now.sec < data->pac_key_refresh_time) {
258 		wpa_printf(MSG_DEBUG, "EAP-FAST: PAC-Key soft timeout; send "
259 			   "an update if authentication succeeds");
260 		data->send_new_pac = 1;
261 	}
262 
263 	eap_fast_derive_master_secret(pac_key, server_random, client_random,
264 				      master_secret);
265 
266 	os_free(buf);
267 
268 	return 1;
269 }
270 
271 
eap_fast_derive_key_auth(struct eap_sm * sm,struct eap_fast_data * data)272 static void eap_fast_derive_key_auth(struct eap_sm *sm,
273 				     struct eap_fast_data *data)
274 {
275 	u8 *sks;
276 
277 	/* RFC 4851, Section 5.1:
278 	 * Extra key material after TLS key_block: session_key_seed[40]
279 	 */
280 
281 	sks = eap_fast_derive_key(sm->cfg->ssl_ctx, data->ssl.conn,
282 				  EAP_FAST_SKS_LEN);
283 	if (sks == NULL) {
284 		wpa_printf(MSG_DEBUG, "EAP-FAST: Failed to derive "
285 			   "session_key_seed");
286 		return;
287 	}
288 
289 	/*
290 	 * RFC 4851, Section 5.2:
291 	 * S-IMCK[0] = session_key_seed
292 	 */
293 	wpa_hexdump_key(MSG_DEBUG,
294 			"EAP-FAST: session_key_seed (SKS = S-IMCK[0])",
295 			sks, EAP_FAST_SKS_LEN);
296 	data->simck_idx = 0;
297 	os_memcpy(data->simck, sks, EAP_FAST_SIMCK_LEN);
298 	os_free(sks);
299 }
300 
301 
eap_fast_derive_key_provisioning(struct eap_sm * sm,struct eap_fast_data * data)302 static void eap_fast_derive_key_provisioning(struct eap_sm *sm,
303 					     struct eap_fast_data *data)
304 {
305 	os_free(data->key_block_p);
306 	data->key_block_p = (struct eap_fast_key_block_provisioning *)
307 		eap_fast_derive_key(sm->cfg->ssl_ctx, data->ssl.conn,
308 				    sizeof(*data->key_block_p));
309 	if (data->key_block_p == NULL) {
310 		wpa_printf(MSG_DEBUG, "EAP-FAST: Failed to derive key block");
311 		return;
312 	}
313 	/*
314 	 * RFC 4851, Section 5.2:
315 	 * S-IMCK[0] = session_key_seed
316 	 */
317 	wpa_hexdump_key(MSG_DEBUG,
318 			"EAP-FAST: session_key_seed (SKS = S-IMCK[0])",
319 			data->key_block_p->session_key_seed,
320 			sizeof(data->key_block_p->session_key_seed));
321 	data->simck_idx = 0;
322 	os_memcpy(data->simck, data->key_block_p->session_key_seed,
323 		  EAP_FAST_SIMCK_LEN);
324 	wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: server_challenge",
325 			data->key_block_p->server_challenge,
326 			sizeof(data->key_block_p->server_challenge));
327 	wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: client_challenge",
328 			data->key_block_p->client_challenge,
329 			sizeof(data->key_block_p->client_challenge));
330 }
331 
332 
eap_fast_get_phase2_key(struct eap_sm * sm,struct eap_fast_data * data,u8 * isk,size_t isk_len)333 static int eap_fast_get_phase2_key(struct eap_sm *sm,
334 				   struct eap_fast_data *data,
335 				   u8 *isk, size_t isk_len)
336 {
337 	u8 *key;
338 	size_t key_len;
339 
340 	os_memset(isk, 0, isk_len);
341 
342 	if (data->phase2_method == NULL || data->phase2_priv == NULL) {
343 		wpa_printf(MSG_DEBUG, "EAP-FAST: Phase 2 method not "
344 			   "available");
345 		return -1;
346 	}
347 
348 	if (data->phase2_method->getKey == NULL)
349 		return 0;
350 
351 	if ((key = data->phase2_method->getKey(sm, data->phase2_priv,
352 					       &key_len)) == NULL) {
353 		wpa_printf(MSG_DEBUG, "EAP-FAST: Could not get key material "
354 			   "from Phase 2");
355 		return -1;
356 	}
357 
358 	if (key_len > isk_len)
359 		key_len = isk_len;
360 	if (key_len == 32 &&
361 	    data->phase2_method->vendor == EAP_VENDOR_IETF &&
362 	    data->phase2_method->method == EAP_TYPE_MSCHAPV2) {
363 		/*
364 		 * EAP-FAST uses reverse order for MS-MPPE keys when deriving
365 		 * MSK from EAP-MSCHAPv2. Swap the keys here to get the correct
366 		 * ISK for EAP-FAST cryptobinding.
367 		 */
368 		os_memcpy(isk, key + 16, 16);
369 		os_memcpy(isk + 16, key, 16);
370 	} else
371 		os_memcpy(isk, key, key_len);
372 	os_free(key);
373 
374 	return 0;
375 }
376 
377 
eap_fast_update_icmk(struct eap_sm * sm,struct eap_fast_data * data)378 static int eap_fast_update_icmk(struct eap_sm *sm, struct eap_fast_data *data)
379 {
380 	u8 isk[32], imck[60];
381 
382 	wpa_printf(MSG_DEBUG, "EAP-FAST: Deriving ICMK[%d] (S-IMCK and CMK)",
383 		   data->simck_idx + 1);
384 
385 	/*
386 	 * RFC 4851, Section 5.2:
387 	 * IMCK[j] = T-PRF(S-IMCK[j-1], "Inner Methods Compound Keys",
388 	 *                 MSK[j], 60)
389 	 * S-IMCK[j] = first 40 octets of IMCK[j]
390 	 * CMK[j] = last 20 octets of IMCK[j]
391 	 */
392 
393 	if (eap_fast_get_phase2_key(sm, data, isk, sizeof(isk)) < 0)
394 		return -1;
395 	wpa_hexdump_key(MSG_MSGDUMP, "EAP-FAST: ISK[j]", isk, sizeof(isk));
396 	sha1_t_prf(data->simck, EAP_FAST_SIMCK_LEN,
397 		   "Inner Methods Compound Keys",
398 		   isk, sizeof(isk), imck, sizeof(imck));
399 	data->simck_idx++;
400 	os_memcpy(data->simck, imck, EAP_FAST_SIMCK_LEN);
401 	wpa_hexdump_key(MSG_MSGDUMP, "EAP-FAST: S-IMCK[j]",
402 			data->simck, EAP_FAST_SIMCK_LEN);
403 	os_memcpy(data->cmk, imck + EAP_FAST_SIMCK_LEN, EAP_FAST_CMK_LEN);
404 	wpa_hexdump_key(MSG_MSGDUMP, "EAP-FAST: CMK[j]",
405 			data->cmk, EAP_FAST_CMK_LEN);
406 
407 	return 0;
408 }
409 
410 
eap_fast_init(struct eap_sm * sm)411 static void * eap_fast_init(struct eap_sm *sm)
412 {
413 	struct eap_fast_data *data;
414 	u8 ciphers[7] = {
415 		TLS_CIPHER_ANON_DH_AES128_SHA,
416 		TLS_CIPHER_AES128_SHA,
417 		TLS_CIPHER_RSA_DHE_AES128_SHA,
418 		TLS_CIPHER_RC4_SHA,
419 		TLS_CIPHER_RSA_DHE_AES256_SHA,
420 		TLS_CIPHER_AES256_SHA,
421 		TLS_CIPHER_NONE
422 	};
423 
424 	data = os_zalloc(sizeof(*data));
425 	if (data == NULL)
426 		return NULL;
427 	data->fast_version = EAP_FAST_VERSION;
428 	data->force_version = -1;
429 	if (sm->user && sm->user->force_version >= 0) {
430 		data->force_version = sm->user->force_version;
431 		wpa_printf(MSG_DEBUG, "EAP-FAST: forcing version %d",
432 			   data->force_version);
433 		data->fast_version = data->force_version;
434 	}
435 	data->state = START;
436 
437 	if (eap_server_tls_ssl_init(sm, &data->ssl, 0, EAP_TYPE_FAST)) {
438 		wpa_printf(MSG_INFO, "EAP-FAST: Failed to initialize SSL.");
439 		eap_fast_reset(sm, data);
440 		return NULL;
441 	}
442 
443 	if (tls_connection_set_cipher_list(sm->cfg->ssl_ctx, data->ssl.conn,
444 					   ciphers) < 0) {
445 		wpa_printf(MSG_INFO, "EAP-FAST: Failed to set TLS cipher "
446 			   "suites");
447 		eap_fast_reset(sm, data);
448 		return NULL;
449 	}
450 
451 	if (tls_connection_set_session_ticket_cb(sm->cfg->ssl_ctx,
452 						 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->cfg->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->cfg->pac_opaque_encr_key,
468 		  sizeof(data->pac_opaque_encr));
469 
470 	if (sm->cfg->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_memdup(sm->cfg->eap_fast_a_id,
476 				 sm->cfg->eap_fast_a_id_len);
477 	if (data->srv_id == NULL) {
478 		eap_fast_reset(sm, data);
479 		return NULL;
480 	}
481 	data->srv_id_len = sm->cfg->eap_fast_a_id_len;
482 
483 	if (sm->cfg->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->cfg->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->cfg->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->cfg->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->cfg->ssl_ctx, data->ssl.conn,
558 			   cipher, sizeof(cipher)) < 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->cfg->ssl_ctx,
878 					       data->ssl.conn)) {
879 			if (eap_fast_phase1_done(sm, data) < 0)
880 				return NULL;
881 			if (data->state == PHASE2_START) {
882 				/*
883 				 * Try to generate Phase 2 data to piggyback
884 				 * with the end of Phase 1 to avoid extra
885 				 * roundtrip.
886 				 */
887 				wpa_printf(MSG_DEBUG, "EAP-FAST: Try to start "
888 					   "Phase 2");
889 				if (eap_fast_process_phase2_start(sm, data))
890 					break;
891 				req = eap_fast_build_phase2_req(sm, data, id);
892 				piggyback = 1;
893 			}
894 		}
895 		break;
896 	case PHASE2_ID:
897 	case PHASE2_METHOD:
898 		req = eap_fast_build_phase2_req(sm, data, id);
899 		break;
900 	case CRYPTO_BINDING:
901 		req = eap_fast_build_crypto_binding(sm, data);
902 		if (data->phase2_method) {
903 			/*
904 			 * Include the start of the next EAP method in the
905 			 * sequence in the same message with Crypto-Binding to
906 			 * save a round-trip.
907 			 */
908 			struct wpabuf *eap;
909 			eap = eap_fast_build_phase2_req(sm, data, id);
910 			req = wpabuf_concat(req, eap);
911 			eap_fast_state(data, PHASE2_METHOD);
912 		}
913 		break;
914 	case REQUEST_PAC:
915 		req = eap_fast_build_pac(sm, data);
916 		break;
917 	default:
918 		wpa_printf(MSG_DEBUG, "EAP-FAST: %s - unexpected state %d",
919 			   __func__, data->state);
920 		return NULL;
921 	}
922 
923 	if (req &&
924 	    eap_fast_encrypt_phase2(sm, data, req, piggyback) < 0)
925 		return NULL;
926 
927 	return eap_server_tls_build_msg(&data->ssl, EAP_TYPE_FAST,
928 					data->fast_version, id);
929 }
930 
931 
eap_fast_check(struct eap_sm * sm,void * priv,struct wpabuf * respData)932 static bool eap_fast_check(struct eap_sm *sm, void *priv,
933 			   struct wpabuf *respData)
934 {
935 	const u8 *pos;
936 	size_t len;
937 
938 	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_FAST, respData, &len);
939 	if (pos == NULL || len < 1) {
940 		wpa_printf(MSG_INFO, "EAP-FAST: Invalid frame");
941 		return true;
942 	}
943 
944 	return false;
945 }
946 
947 
eap_fast_phase2_init(struct eap_sm * sm,struct eap_fast_data * data,int vendor,enum eap_type eap_type)948 static int eap_fast_phase2_init(struct eap_sm *sm, struct eap_fast_data *data,
949 				int vendor, enum eap_type eap_type)
950 {
951 	if (data->phase2_priv && data->phase2_method) {
952 		data->phase2_method->reset(sm, data->phase2_priv);
953 		data->phase2_method = NULL;
954 		data->phase2_priv = NULL;
955 	}
956 	data->phase2_method = eap_server_get_eap_method(vendor, 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 	int next_vendor = EAP_VENDOR_IETF;
979 	enum eap_type next_type = EAP_TYPE_NONE;
980 	struct eap_hdr *hdr;
981 	u8 *pos;
982 	size_t left;
983 	struct wpabuf buf;
984 	const struct eap_method *m = data->phase2_method;
985 	void *priv = data->phase2_priv;
986 
987 	if (priv == NULL) {
988 		wpa_printf(MSG_DEBUG, "EAP-FAST: %s - Phase2 not "
989 			   "initialized?!", __func__);
990 		return;
991 	}
992 
993 	hdr = (struct eap_hdr *) in_data;
994 	pos = (u8 *) (hdr + 1);
995 
996 	if (in_len > sizeof(*hdr) && *pos == EAP_TYPE_NAK) {
997 		left = in_len - sizeof(*hdr);
998 		wpa_hexdump(MSG_DEBUG, "EAP-FAST: Phase2 type Nak'ed; "
999 			    "allowed types", pos + 1, left - 1);
1000 #ifdef EAP_SERVER_TNC
1001 		if (m && m->vendor == EAP_VENDOR_IETF &&
1002 		    m->method == EAP_TYPE_TNC) {
1003 			wpa_printf(MSG_DEBUG, "EAP-FAST: Peer Nak'ed required "
1004 				   "TNC negotiation");
1005 			next_vendor = EAP_VENDOR_IETF;
1006 			next_type = eap_fast_req_failure(sm, data);
1007 			eap_fast_phase2_init(sm, data, next_vendor, next_type);
1008 			return;
1009 		}
1010 #endif /* EAP_SERVER_TNC */
1011 		eap_sm_process_nak(sm, pos + 1, left - 1);
1012 		if (sm->user && sm->user_eap_method_index < EAP_MAX_METHODS &&
1013 		    sm->user->methods[sm->user_eap_method_index].method !=
1014 		    EAP_TYPE_NONE) {
1015 			next_vendor = sm->user->methods[
1016 				sm->user_eap_method_index].vendor;
1017 			next_type = sm->user->methods[
1018 				sm->user_eap_method_index++].method;
1019 			wpa_printf(MSG_DEBUG, "EAP-FAST: try EAP type %u:%u",
1020 				   next_vendor, next_type);
1021 		} else {
1022 			next_vendor = EAP_VENDOR_IETF;
1023 			next_type = eap_fast_req_failure(sm, data);
1024 		}
1025 		eap_fast_phase2_init(sm, data, next_vendor, next_type);
1026 		return;
1027 	}
1028 
1029 	wpabuf_set(&buf, in_data, in_len);
1030 
1031 	if (m->check(sm, priv, &buf)) {
1032 		wpa_printf(MSG_DEBUG, "EAP-FAST: Phase2 check() asked to "
1033 			   "ignore the packet");
1034 		eap_fast_req_failure(sm, data);
1035 		return;
1036 	}
1037 
1038 	m->process(sm, priv, &buf);
1039 
1040 	if (!m->isDone(sm, priv))
1041 		return;
1042 
1043 	if (!m->isSuccess(sm, priv)) {
1044 		wpa_printf(MSG_DEBUG, "EAP-FAST: Phase2 method failed");
1045 		next_vendor = EAP_VENDOR_IETF;
1046 		next_type = eap_fast_req_failure(sm, data);
1047 		eap_fast_phase2_init(sm, data, next_vendor, next_type);
1048 		return;
1049 	}
1050 
1051 	switch (data->state) {
1052 	case PHASE2_ID:
1053 		if (eap_user_get(sm, sm->identity, sm->identity_len, 1) != 0) {
1054 			wpa_hexdump_ascii(MSG_DEBUG, "EAP-FAST: Phase2 "
1055 					  "Identity not found in the user "
1056 					  "database",
1057 					  sm->identity, sm->identity_len);
1058 			next_vendor = EAP_VENDOR_IETF;
1059 			next_type = eap_fast_req_failure(sm, data);
1060 			break;
1061 		}
1062 
1063 		eap_fast_state(data, PHASE2_METHOD);
1064 		if (data->anon_provisioning) {
1065 			/*
1066 			 * Only EAP-MSCHAPv2 is allowed for anonymous
1067 			 * provisioning.
1068 			 */
1069 			next_vendor = EAP_VENDOR_IETF;
1070 			next_type = EAP_TYPE_MSCHAPV2;
1071 			sm->user_eap_method_index = 0;
1072 		} else {
1073 			next_vendor = sm->user->methods[0].vendor;
1074 			next_type = sm->user->methods[0].method;
1075 			sm->user_eap_method_index = 1;
1076 		}
1077 		wpa_printf(MSG_DEBUG, "EAP-FAST: try EAP type %u:%u",
1078 			   next_vendor, next_type);
1079 		break;
1080 	case PHASE2_METHOD:
1081 	case CRYPTO_BINDING:
1082 		eap_fast_update_icmk(sm, data);
1083 		eap_fast_state(data, CRYPTO_BINDING);
1084 		data->eap_seq++;
1085 		next_vendor = EAP_VENDOR_IETF;
1086 		next_type = EAP_TYPE_NONE;
1087 #ifdef EAP_SERVER_TNC
1088 		if (sm->cfg->tnc && !data->tnc_started) {
1089 			wpa_printf(MSG_DEBUG, "EAP-FAST: Initialize TNC");
1090 			next_vendor = EAP_VENDOR_IETF;
1091 			next_type = EAP_TYPE_TNC;
1092 			data->tnc_started = 1;
1093 		}
1094 #endif /* EAP_SERVER_TNC */
1095 		break;
1096 	case FAILURE:
1097 		break;
1098 	default:
1099 		wpa_printf(MSG_DEBUG, "EAP-FAST: %s - unexpected state %d",
1100 			   __func__, data->state);
1101 		break;
1102 	}
1103 
1104 	eap_fast_phase2_init(sm, data, next_vendor, next_type);
1105 }
1106 
1107 
eap_fast_process_phase2_eap(struct eap_sm * sm,struct eap_fast_data * data,u8 * in_data,size_t in_len)1108 static void eap_fast_process_phase2_eap(struct eap_sm *sm,
1109 					struct eap_fast_data *data,
1110 					u8 *in_data, size_t in_len)
1111 {
1112 	struct eap_hdr *hdr;
1113 	size_t len;
1114 
1115 	hdr = (struct eap_hdr *) in_data;
1116 	if (in_len < (int) sizeof(*hdr)) {
1117 		wpa_printf(MSG_INFO, "EAP-FAST: Too short Phase 2 "
1118 			   "EAP frame (len=%lu)", (unsigned long) in_len);
1119 		eap_fast_req_failure(sm, data);
1120 		return;
1121 	}
1122 	len = be_to_host16(hdr->length);
1123 	if (len > in_len) {
1124 		wpa_printf(MSG_INFO, "EAP-FAST: Length mismatch in "
1125 			   "Phase 2 EAP frame (len=%lu hdr->length=%lu)",
1126 			   (unsigned long) in_len, (unsigned long) len);
1127 		eap_fast_req_failure(sm, data);
1128 		return;
1129 	}
1130 	wpa_printf(MSG_DEBUG, "EAP-FAST: Received Phase 2: code=%d "
1131 		   "identifier=%d length=%lu", hdr->code, hdr->identifier,
1132 		   (unsigned long) len);
1133 	switch (hdr->code) {
1134 	case EAP_CODE_RESPONSE:
1135 		eap_fast_process_phase2_response(sm, data, (u8 *) hdr, len);
1136 		break;
1137 	default:
1138 		wpa_printf(MSG_INFO, "EAP-FAST: Unexpected code=%d in "
1139 			   "Phase 2 EAP header", hdr->code);
1140 		break;
1141 	}
1142 }
1143 
1144 
eap_fast_parse_tlvs(struct wpabuf * data,struct eap_fast_tlv_parse * tlv)1145 static int eap_fast_parse_tlvs(struct wpabuf *data,
1146 			       struct eap_fast_tlv_parse *tlv)
1147 {
1148 	int mandatory, tlv_type, res;
1149 	size_t len;
1150 	u8 *pos, *end;
1151 
1152 	os_memset(tlv, 0, sizeof(*tlv));
1153 
1154 	pos = wpabuf_mhead(data);
1155 	end = pos + wpabuf_len(data);
1156 	while (end - pos > 4) {
1157 		mandatory = pos[0] & 0x80;
1158 		tlv_type = WPA_GET_BE16(pos) & 0x3fff;
1159 		pos += 2;
1160 		len = WPA_GET_BE16(pos);
1161 		pos += 2;
1162 		if (len > (size_t) (end - pos)) {
1163 			wpa_printf(MSG_INFO, "EAP-FAST: TLV overflow");
1164 			return -1;
1165 		}
1166 		wpa_printf(MSG_DEBUG, "EAP-FAST: Received Phase 2: "
1167 			   "TLV type %d length %u%s",
1168 			   tlv_type, (unsigned int) len,
1169 			   mandatory ? " (mandatory)" : "");
1170 
1171 		res = eap_fast_parse_tlv(tlv, tlv_type, pos, len);
1172 		if (res == -2)
1173 			break;
1174 		if (res < 0) {
1175 			if (mandatory) {
1176 				wpa_printf(MSG_DEBUG, "EAP-FAST: Nak unknown "
1177 					   "mandatory TLV type %d", tlv_type);
1178 				/* TODO: generate Nak TLV */
1179 				break;
1180 			} else {
1181 				wpa_printf(MSG_DEBUG, "EAP-FAST: Ignored "
1182 					   "unknown optional TLV type %d",
1183 					   tlv_type);
1184 			}
1185 		}
1186 
1187 		pos += len;
1188 	}
1189 
1190 	return 0;
1191 }
1192 
1193 
eap_fast_validate_crypto_binding(struct eap_fast_data * data,struct eap_tlv_crypto_binding_tlv * b,size_t bind_len)1194 static int eap_fast_validate_crypto_binding(
1195 	struct eap_fast_data *data, struct eap_tlv_crypto_binding_tlv *b,
1196 	size_t bind_len)
1197 {
1198 	u8 cmac[SHA1_MAC_LEN];
1199 
1200 	wpa_printf(MSG_DEBUG, "EAP-FAST: Reply Crypto-Binding TLV: "
1201 		   "Version %d Received Version %d SubType %d",
1202 		   b->version, b->received_version, b->subtype);
1203 	wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: NONCE",
1204 		    b->nonce, sizeof(b->nonce));
1205 	wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: Compound MAC",
1206 		    b->compound_mac, sizeof(b->compound_mac));
1207 
1208 	if (b->version != EAP_FAST_VERSION ||
1209 	    b->received_version != EAP_FAST_VERSION) {
1210 		wpa_printf(MSG_DEBUG, "EAP-FAST: Unexpected version "
1211 			   "in Crypto-Binding: version %d "
1212 			   "received_version %d", b->version,
1213 			   b->received_version);
1214 		return -1;
1215 	}
1216 
1217 	if (b->subtype != EAP_TLV_CRYPTO_BINDING_SUBTYPE_RESPONSE) {
1218 		wpa_printf(MSG_DEBUG, "EAP-FAST: Unexpected subtype in "
1219 			   "Crypto-Binding: %d", b->subtype);
1220 		return -1;
1221 	}
1222 
1223 	if (os_memcmp_const(data->crypto_binding_nonce, b->nonce, 31) != 0 ||
1224 	    (data->crypto_binding_nonce[31] | 1) != b->nonce[31]) {
1225 		wpa_printf(MSG_DEBUG, "EAP-FAST: Invalid nonce in "
1226 			   "Crypto-Binding");
1227 		return -1;
1228 	}
1229 
1230 	os_memcpy(cmac, b->compound_mac, sizeof(cmac));
1231 	os_memset(b->compound_mac, 0, sizeof(cmac));
1232 	wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: Crypto-Binding TLV for "
1233 		    "Compound MAC calculation",
1234 		    (u8 *) b, bind_len);
1235 	hmac_sha1(data->cmk, EAP_FAST_CMK_LEN, (u8 *) b, bind_len,
1236 		  b->compound_mac);
1237 	if (os_memcmp_const(cmac, b->compound_mac, sizeof(cmac)) != 0) {
1238 		wpa_hexdump(MSG_MSGDUMP,
1239 			    "EAP-FAST: Calculated Compound MAC",
1240 			    b->compound_mac, sizeof(cmac));
1241 		wpa_printf(MSG_INFO, "EAP-FAST: Compound MAC did not "
1242 			   "match");
1243 		return -1;
1244 	}
1245 
1246 	return 0;
1247 }
1248 
1249 
eap_fast_pac_type(u8 * pac,size_t len,u16 type)1250 static int eap_fast_pac_type(u8 *pac, size_t len, u16 type)
1251 {
1252 	struct eap_tlv_pac_type_tlv *tlv;
1253 
1254 	if (pac == NULL || len != sizeof(*tlv))
1255 		return 0;
1256 
1257 	tlv = (struct eap_tlv_pac_type_tlv *) pac;
1258 
1259 	return be_to_host16(tlv->tlv_type) == PAC_TYPE_PAC_TYPE &&
1260 		be_to_host16(tlv->length) == 2 &&
1261 		be_to_host16(tlv->pac_type) == type;
1262 }
1263 
1264 
eap_fast_process_phase2_tlvs(struct eap_sm * sm,struct eap_fast_data * data,struct wpabuf * in_data)1265 static void eap_fast_process_phase2_tlvs(struct eap_sm *sm,
1266 					 struct eap_fast_data *data,
1267 					 struct wpabuf *in_data)
1268 {
1269 	struct eap_fast_tlv_parse tlv;
1270 	int check_crypto_binding = data->state == CRYPTO_BINDING;
1271 
1272 	if (eap_fast_parse_tlvs(in_data, &tlv) < 0) {
1273 		wpa_printf(MSG_DEBUG, "EAP-FAST: Failed to parse received "
1274 			   "Phase 2 TLVs");
1275 		return;
1276 	}
1277 
1278 	if (tlv.result == EAP_TLV_RESULT_FAILURE) {
1279 		wpa_printf(MSG_DEBUG, "EAP-FAST: Result TLV indicated "
1280 			   "failure");
1281 		eap_fast_state(data, FAILURE);
1282 		return;
1283 	}
1284 
1285 	if (data->state == REQUEST_PAC) {
1286 		u16 type, len, res;
1287 		if (tlv.pac == NULL || tlv.pac_len < 6) {
1288 			wpa_printf(MSG_DEBUG, "EAP-FAST: No PAC "
1289 				   "Acknowledgement received");
1290 			eap_fast_state(data, FAILURE);
1291 			return;
1292 		}
1293 
1294 		type = WPA_GET_BE16(tlv.pac);
1295 		len = WPA_GET_BE16(tlv.pac + 2);
1296 		res = WPA_GET_BE16(tlv.pac + 4);
1297 
1298 		if (type != PAC_TYPE_PAC_ACKNOWLEDGEMENT || len != 2 ||
1299 		    res != EAP_TLV_RESULT_SUCCESS) {
1300 			wpa_printf(MSG_DEBUG, "EAP-FAST: PAC TLV did not "
1301 				   "contain acknowledgement");
1302 			eap_fast_state(data, FAILURE);
1303 			return;
1304 		}
1305 
1306 		wpa_printf(MSG_DEBUG, "EAP-FAST: PAC-Acknowledgement received "
1307 			   "- PAC provisioning succeeded");
1308 		eap_fast_state(data, (data->anon_provisioning ||
1309 				      data->send_new_pac == 2) ?
1310 			       FAILURE : SUCCESS);
1311 		return;
1312 	}
1313 
1314 	if (check_crypto_binding) {
1315 		if (tlv.crypto_binding == NULL) {
1316 			wpa_printf(MSG_DEBUG, "EAP-FAST: No Crypto-Binding "
1317 				   "TLV received");
1318 			eap_fast_state(data, FAILURE);
1319 			return;
1320 		}
1321 
1322 		if (data->final_result &&
1323 		    tlv.result != EAP_TLV_RESULT_SUCCESS) {
1324 			wpa_printf(MSG_DEBUG, "EAP-FAST: Crypto-Binding TLV "
1325 				   "without Success Result");
1326 			eap_fast_state(data, FAILURE);
1327 			return;
1328 		}
1329 
1330 		if (!data->final_result &&
1331 		    tlv.iresult != EAP_TLV_RESULT_SUCCESS) {
1332 			wpa_printf(MSG_DEBUG, "EAP-FAST: Crypto-Binding TLV "
1333 				   "without intermediate Success Result");
1334 			eap_fast_state(data, FAILURE);
1335 			return;
1336 		}
1337 
1338 		if (eap_fast_validate_crypto_binding(data, tlv.crypto_binding,
1339 						     tlv.crypto_binding_len)) {
1340 			eap_fast_state(data, FAILURE);
1341 			return;
1342 		}
1343 
1344 		wpa_printf(MSG_DEBUG, "EAP-FAST: Valid Crypto-Binding TLV "
1345 			   "received");
1346 		if (data->final_result) {
1347 			wpa_printf(MSG_DEBUG, "EAP-FAST: Authentication "
1348 				   "completed successfully");
1349 		}
1350 
1351 		if (data->anon_provisioning &&
1352 		    sm->cfg->eap_fast_prov != ANON_PROV &&
1353 		    sm->cfg->eap_fast_prov != BOTH_PROV) {
1354 			wpa_printf(MSG_DEBUG, "EAP-FAST: Client is trying to "
1355 				   "use unauthenticated provisioning which is "
1356 				   "disabled");
1357 			eap_fast_state(data, FAILURE);
1358 			return;
1359 		}
1360 
1361 		if (sm->cfg->eap_fast_prov != AUTH_PROV &&
1362 		    sm->cfg->eap_fast_prov != BOTH_PROV &&
1363 		    tlv.request_action == EAP_TLV_ACTION_PROCESS_TLV &&
1364 		    eap_fast_pac_type(tlv.pac, tlv.pac_len,
1365 				      PAC_TYPE_TUNNEL_PAC)) {
1366 			wpa_printf(MSG_DEBUG, "EAP-FAST: Client is trying to "
1367 				   "use authenticated provisioning which is "
1368 				   "disabled");
1369 			eap_fast_state(data, FAILURE);
1370 			return;
1371 		}
1372 
1373 		if (data->anon_provisioning ||
1374 		    (tlv.request_action == EAP_TLV_ACTION_PROCESS_TLV &&
1375 		     eap_fast_pac_type(tlv.pac, tlv.pac_len,
1376 				       PAC_TYPE_TUNNEL_PAC))) {
1377 			wpa_printf(MSG_DEBUG, "EAP-FAST: Requested a new "
1378 				   "Tunnel PAC");
1379 			eap_fast_state(data, REQUEST_PAC);
1380 		} else if (data->send_new_pac) {
1381 			wpa_printf(MSG_DEBUG, "EAP-FAST: Server triggered "
1382 				   "re-keying of Tunnel PAC");
1383 			eap_fast_state(data, REQUEST_PAC);
1384 		} else if (data->final_result)
1385 			eap_fast_state(data, SUCCESS);
1386 	}
1387 
1388 	if (tlv.eap_payload_tlv) {
1389 		eap_fast_process_phase2_eap(sm, data, tlv.eap_payload_tlv,
1390 					    tlv.eap_payload_tlv_len);
1391 	}
1392 }
1393 
1394 
eap_fast_process_phase2(struct eap_sm * sm,struct eap_fast_data * data,struct wpabuf * in_buf)1395 static void eap_fast_process_phase2(struct eap_sm *sm,
1396 				    struct eap_fast_data *data,
1397 				    struct wpabuf *in_buf)
1398 {
1399 	struct wpabuf *in_decrypted;
1400 
1401 	wpa_printf(MSG_DEBUG, "EAP-FAST: Received %lu bytes encrypted data for"
1402 		   " Phase 2", (unsigned long) wpabuf_len(in_buf));
1403 
1404 	if (data->pending_phase2_resp) {
1405 		wpa_printf(MSG_DEBUG, "EAP-PEAP: Pending Phase 2 response - "
1406 			   "skip decryption and use old data");
1407 		eap_fast_process_phase2_tlvs(sm, data,
1408 					     data->pending_phase2_resp);
1409 		wpabuf_free(data->pending_phase2_resp);
1410 		data->pending_phase2_resp = NULL;
1411 		return;
1412 	}
1413 
1414 	in_decrypted = tls_connection_decrypt(sm->cfg->ssl_ctx, data->ssl.conn,
1415 					      in_buf);
1416 	if (in_decrypted == NULL) {
1417 		wpa_printf(MSG_INFO, "EAP-FAST: Failed to decrypt Phase 2 "
1418 			   "data");
1419 		eap_fast_state(data, FAILURE);
1420 		return;
1421 	}
1422 
1423 	wpa_hexdump_buf_key(MSG_DEBUG, "EAP-FAST: Decrypted Phase 2 TLVs",
1424 			    in_decrypted);
1425 
1426 	eap_fast_process_phase2_tlvs(sm, data, in_decrypted);
1427 
1428 	if (sm->method_pending == METHOD_PENDING_WAIT) {
1429 		wpa_printf(MSG_DEBUG, "EAP-FAST: Phase2 method is in "
1430 			   "pending wait state - save decrypted response");
1431 		wpabuf_free(data->pending_phase2_resp);
1432 		data->pending_phase2_resp = in_decrypted;
1433 		return;
1434 	}
1435 
1436 	wpabuf_free(in_decrypted);
1437 }
1438 
1439 
eap_fast_process_version(struct eap_sm * sm,void * priv,int peer_version)1440 static int eap_fast_process_version(struct eap_sm *sm, void *priv,
1441 				    int peer_version)
1442 {
1443 	struct eap_fast_data *data = priv;
1444 
1445 	data->peer_version = peer_version;
1446 
1447 	if (data->force_version >= 0 && peer_version != data->force_version) {
1448 		wpa_printf(MSG_INFO, "EAP-FAST: peer did not select the forced"
1449 			   " version (forced=%d peer=%d) - reject",
1450 			   data->force_version, peer_version);
1451 		return -1;
1452 	}
1453 
1454 	if (peer_version < data->fast_version) {
1455 		wpa_printf(MSG_DEBUG, "EAP-FAST: peer ver=%d, own ver=%d; "
1456 			   "use version %d",
1457 			   peer_version, data->fast_version, peer_version);
1458 		data->fast_version = peer_version;
1459 	}
1460 
1461 	return 0;
1462 }
1463 
1464 
eap_fast_process_phase1(struct eap_sm * sm,struct eap_fast_data * data)1465 static int eap_fast_process_phase1(struct eap_sm *sm,
1466 				   struct eap_fast_data *data)
1467 {
1468 	if (eap_server_tls_phase1(sm, &data->ssl) < 0) {
1469 		wpa_printf(MSG_INFO, "EAP-FAST: TLS processing failed");
1470 		eap_fast_state(data, FAILURE);
1471 		return -1;
1472 	}
1473 
1474 	if (!tls_connection_established(sm->cfg->ssl_ctx, data->ssl.conn) ||
1475 	    wpabuf_len(data->ssl.tls_out) > 0)
1476 		return 1;
1477 
1478 	/*
1479 	 * Phase 1 was completed with the received message (e.g., when using
1480 	 * abbreviated handshake), so Phase 2 can be started immediately
1481 	 * without having to send through an empty message to the peer.
1482 	 */
1483 
1484 	return eap_fast_phase1_done(sm, data);
1485 }
1486 
1487 
eap_fast_process_phase2_start(struct eap_sm * sm,struct eap_fast_data * data)1488 static int eap_fast_process_phase2_start(struct eap_sm *sm,
1489 					 struct eap_fast_data *data)
1490 {
1491 	int next_vendor;
1492 	enum eap_type next_type;
1493 
1494 	if (data->identity) {
1495 		os_free(sm->identity);
1496 		sm->identity = data->identity;
1497 		data->identity = NULL;
1498 		sm->identity_len = data->identity_len;
1499 		data->identity_len = 0;
1500 		sm->require_identity_match = 1;
1501 		if (eap_user_get(sm, sm->identity, sm->identity_len, 1) != 0) {
1502 			wpa_hexdump_ascii(MSG_DEBUG, "EAP-FAST: "
1503 					  "Phase2 Identity not found "
1504 					  "in the user database",
1505 					  sm->identity, sm->identity_len);
1506 			next_vendor = EAP_VENDOR_IETF;
1507 			next_type = eap_fast_req_failure(sm, data);
1508 		} else {
1509 			wpa_printf(MSG_DEBUG, "EAP-FAST: Identity already "
1510 				   "known - skip Phase 2 Identity Request");
1511 			next_vendor = sm->user->methods[0].vendor;
1512 			next_type = sm->user->methods[0].method;
1513 			sm->user_eap_method_index = 1;
1514 		}
1515 
1516 		eap_fast_state(data, PHASE2_METHOD);
1517 	} else {
1518 		eap_fast_state(data, PHASE2_ID);
1519 		next_vendor = EAP_VENDOR_IETF;
1520 		next_type = EAP_TYPE_IDENTITY;
1521 	}
1522 
1523 	return eap_fast_phase2_init(sm, data, next_vendor, next_type);
1524 }
1525 
1526 
eap_fast_process_msg(struct eap_sm * sm,void * priv,const struct wpabuf * respData)1527 static void eap_fast_process_msg(struct eap_sm *sm, void *priv,
1528 				 const struct wpabuf *respData)
1529 {
1530 	struct eap_fast_data *data = priv;
1531 
1532 	switch (data->state) {
1533 	case PHASE1:
1534 		if (eap_fast_process_phase1(sm, data))
1535 			break;
1536 
1537 		/* fall through */
1538 	case PHASE2_START:
1539 		eap_fast_process_phase2_start(sm, data);
1540 		break;
1541 	case PHASE2_ID:
1542 	case PHASE2_METHOD:
1543 	case CRYPTO_BINDING:
1544 	case REQUEST_PAC:
1545 		eap_fast_process_phase2(sm, data, data->ssl.tls_in);
1546 		break;
1547 	default:
1548 		wpa_printf(MSG_DEBUG, "EAP-FAST: Unexpected state %d in %s",
1549 			   data->state, __func__);
1550 		break;
1551 	}
1552 }
1553 
1554 
eap_fast_process(struct eap_sm * sm,void * priv,struct wpabuf * respData)1555 static void eap_fast_process(struct eap_sm *sm, void *priv,
1556 			     struct wpabuf *respData)
1557 {
1558 	struct eap_fast_data *data = priv;
1559 	if (eap_server_tls_process(sm, &data->ssl, respData, data,
1560 				   EAP_TYPE_FAST, eap_fast_process_version,
1561 				   eap_fast_process_msg) < 0)
1562 		eap_fast_state(data, FAILURE);
1563 }
1564 
1565 
eap_fast_isDone(struct eap_sm * sm,void * priv)1566 static bool eap_fast_isDone(struct eap_sm *sm, void *priv)
1567 {
1568 	struct eap_fast_data *data = priv;
1569 	return data->state == SUCCESS || data->state == FAILURE;
1570 }
1571 
1572 
eap_fast_getKey(struct eap_sm * sm,void * priv,size_t * len)1573 static u8 * eap_fast_getKey(struct eap_sm *sm, void *priv, size_t *len)
1574 {
1575 	struct eap_fast_data *data = priv;
1576 	u8 *eapKeyData;
1577 
1578 	if (data->state != SUCCESS)
1579 		return NULL;
1580 
1581 	eapKeyData = os_malloc(EAP_FAST_KEY_LEN);
1582 	if (eapKeyData == NULL)
1583 		return NULL;
1584 
1585 	if (eap_fast_derive_eap_msk(data->simck, eapKeyData) < 0) {
1586 		os_free(eapKeyData);
1587 		return NULL;
1588 	}
1589 	*len = EAP_FAST_KEY_LEN;
1590 
1591 	return eapKeyData;
1592 }
1593 
1594 
eap_fast_get_emsk(struct eap_sm * sm,void * priv,size_t * len)1595 static u8 * eap_fast_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
1596 {
1597 	struct eap_fast_data *data = priv;
1598 	u8 *eapKeyData;
1599 
1600 	if (data->state != SUCCESS)
1601 		return NULL;
1602 
1603 	eapKeyData = os_malloc(EAP_EMSK_LEN);
1604 	if (eapKeyData == NULL)
1605 		return NULL;
1606 
1607 	if (eap_fast_derive_eap_emsk(data->simck, eapKeyData) < 0) {
1608 		os_free(eapKeyData);
1609 		return NULL;
1610 	}
1611 	*len = EAP_EMSK_LEN;
1612 
1613 	return eapKeyData;
1614 }
1615 
1616 
eap_fast_isSuccess(struct eap_sm * sm,void * priv)1617 static bool eap_fast_isSuccess(struct eap_sm *sm, void *priv)
1618 {
1619 	struct eap_fast_data *data = priv;
1620 	return data->state == SUCCESS;
1621 }
1622 
1623 
eap_fast_get_session_id(struct eap_sm * sm,void * priv,size_t * len)1624 static u8 * eap_fast_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
1625 {
1626 	struct eap_fast_data *data = priv;
1627 
1628 	if (data->state != SUCCESS)
1629 		return NULL;
1630 
1631 	return eap_server_tls_derive_session_id(sm, &data->ssl, EAP_TYPE_FAST,
1632 						len);
1633 }
1634 
1635 
eap_server_fast_register(void)1636 int eap_server_fast_register(void)
1637 {
1638 	struct eap_method *eap;
1639 
1640 	eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
1641 				      EAP_VENDOR_IETF, EAP_TYPE_FAST, "FAST");
1642 	if (eap == NULL)
1643 		return -1;
1644 
1645 	eap->init = eap_fast_init;
1646 	eap->reset = eap_fast_reset;
1647 	eap->buildReq = eap_fast_buildReq;
1648 	eap->check = eap_fast_check;
1649 	eap->process = eap_fast_process;
1650 	eap->isDone = eap_fast_isDone;
1651 	eap->getKey = eap_fast_getKey;
1652 	eap->get_emsk = eap_fast_get_emsk;
1653 	eap->isSuccess = eap_fast_isSuccess;
1654 	eap->getSessionId = eap_fast_get_session_id;
1655 
1656 	return eap_server_method_register(eap);
1657 }
1658