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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, (pac_opaque_len - 8) / 8,
165 		       pac_opaque, buf) < 0) {
166 		wpa_printf(MSG_DEBUG, "EAP-FAST: Failed to decrypt "
167 			   "PAC-Opaque");
168 		os_free(buf);
169 		/*
170 		 * This may have been caused by server changing the PAC-Opaque
171 		 * encryption key, so just ignore this PAC-Opaque instead of
172 		 * failing the authentication completely. Provisioning can now
173 		 * be used to provision a new PAC.
174 		 */
175 		return 0;
176 	}
177 
178 	end = buf + pac_opaque_len - 8;
179 	wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: Decrypted PAC-Opaque",
180 			buf, end - buf);
181 
182 	pos = buf;
183 	while (pos + 1 < end) {
184 		if (pos + 2 + pos[1] > end)
185 			break;
186 
187 		switch (*pos) {
188 		case PAC_OPAQUE_TYPE_PAD:
189 			pos = end;
190 			goto done;
191 		case PAC_OPAQUE_TYPE_KEY:
192 			if (pos[1] != EAP_FAST_PAC_KEY_LEN) {
193 				wpa_printf(MSG_DEBUG, "EAP-FAST: Invalid "
194 					   "PAC-Key length %d", pos[1]);
195 				os_free(buf);
196 				return -1;
197 			}
198 			pac_key = pos + 2;
199 			wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: PAC-Key from "
200 					"decrypted PAC-Opaque",
201 					pac_key, EAP_FAST_PAC_KEY_LEN);
202 			break;
203 		case PAC_OPAQUE_TYPE_LIFETIME:
204 			if (pos[1] != 4) {
205 				wpa_printf(MSG_DEBUG, "EAP-FAST: Invalid "
206 					   "PAC-Key lifetime length %d",
207 					   pos[1]);
208 				os_free(buf);
209 				return -1;
210 			}
211 			lifetime = WPA_GET_BE32(pos + 2);
212 			break;
213 		case PAC_OPAQUE_TYPE_IDENTITY:
214 			identity = pos + 2;
215 			identity_len = pos[1];
216 			break;
217 		}
218 
219 		pos += 2 + pos[1];
220 	}
221 done:
222 
223 	if (pac_key == NULL) {
224 		wpa_printf(MSG_DEBUG, "EAP-FAST: No PAC-Key included in "
225 			   "PAC-Opaque");
226 		os_free(buf);
227 		return -1;
228 	}
229 
230 	if (identity) {
231 		wpa_hexdump_ascii(MSG_DEBUG, "EAP-FAST: Identity from "
232 				  "PAC-Opaque", identity, identity_len);
233 		os_free(data->identity);
234 		data->identity = os_malloc(identity_len);
235 		if (data->identity) {
236 			os_memcpy(data->identity, identity, identity_len);
237 			data->identity_len = identity_len;
238 		}
239 	}
240 
241 	if (os_get_time(&now) < 0 || lifetime <= 0 || now.sec > lifetime) {
242 		wpa_printf(MSG_DEBUG, "EAP-FAST: PAC-Key not valid anymore "
243 			   "(lifetime=%ld now=%ld)", lifetime, now.sec);
244 		data->send_new_pac = 2;
245 		/*
246 		 * Allow PAC to be used to allow a PAC update with some level
247 		 * of server authentication (i.e., do not fall back to full TLS
248 		 * handshake since we cannot be sure that the peer would be
249 		 * able to validate server certificate now). However, reject
250 		 * the authentication since the PAC was not valid anymore. Peer
251 		 * can connect again with the newly provisioned PAC after this.
252 		 */
253 	} else if (lifetime - now.sec < data->pac_key_refresh_time) {
254 		wpa_printf(MSG_DEBUG, "EAP-FAST: PAC-Key soft timeout; send "
255 			   "an update if authentication succeeds");
256 		data->send_new_pac = 1;
257 	}
258 
259 	eap_fast_derive_master_secret(pac_key, server_random, client_random,
260 				      master_secret);
261 
262 	os_free(buf);
263 
264 	return 1;
265 }
266 
267 
eap_fast_derive_key_auth(struct eap_sm * sm,struct eap_fast_data * data)268 static void eap_fast_derive_key_auth(struct eap_sm *sm,
269 				     struct eap_fast_data *data)
270 {
271 	u8 *sks;
272 
273 	/* RFC 4851, Section 5.1:
274 	 * Extra key material after TLS key_block: session_key_seed[40]
275 	 */
276 
277 	sks = eap_fast_derive_key(sm->ssl_ctx, data->ssl.conn, "key expansion",
278 				  EAP_FAST_SKS_LEN);
279 	if (sks == NULL) {
280 		wpa_printf(MSG_DEBUG, "EAP-FAST: Failed to derive "
281 			   "session_key_seed");
282 		return;
283 	}
284 
285 	/*
286 	 * RFC 4851, Section 5.2:
287 	 * S-IMCK[0] = session_key_seed
288 	 */
289 	wpa_hexdump_key(MSG_DEBUG,
290 			"EAP-FAST: session_key_seed (SKS = S-IMCK[0])",
291 			sks, EAP_FAST_SKS_LEN);
292 	data->simck_idx = 0;
293 	os_memcpy(data->simck, sks, EAP_FAST_SIMCK_LEN);
294 	os_free(sks);
295 }
296 
297 
eap_fast_derive_key_provisioning(struct eap_sm * sm,struct eap_fast_data * data)298 static void eap_fast_derive_key_provisioning(struct eap_sm *sm,
299 					     struct eap_fast_data *data)
300 {
301 	os_free(data->key_block_p);
302 	data->key_block_p = (struct eap_fast_key_block_provisioning *)
303 		eap_fast_derive_key(sm->ssl_ctx, data->ssl.conn,
304 				    "key expansion",
305 				    sizeof(*data->key_block_p));
306 	if (data->key_block_p == NULL) {
307 		wpa_printf(MSG_DEBUG, "EAP-FAST: Failed to derive key block");
308 		return;
309 	}
310 	/*
311 	 * RFC 4851, Section 5.2:
312 	 * S-IMCK[0] = session_key_seed
313 	 */
314 	wpa_hexdump_key(MSG_DEBUG,
315 			"EAP-FAST: session_key_seed (SKS = S-IMCK[0])",
316 			data->key_block_p->session_key_seed,
317 			sizeof(data->key_block_p->session_key_seed));
318 	data->simck_idx = 0;
319 	os_memcpy(data->simck, data->key_block_p->session_key_seed,
320 		  EAP_FAST_SIMCK_LEN);
321 	wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: server_challenge",
322 			data->key_block_p->server_challenge,
323 			sizeof(data->key_block_p->server_challenge));
324 	wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: client_challenge",
325 			data->key_block_p->client_challenge,
326 			sizeof(data->key_block_p->client_challenge));
327 }
328 
329 
eap_fast_get_phase2_key(struct eap_sm * sm,struct eap_fast_data * data,u8 * isk,size_t isk_len)330 static int eap_fast_get_phase2_key(struct eap_sm *sm,
331 				   struct eap_fast_data *data,
332 				   u8 *isk, size_t isk_len)
333 {
334 	u8 *key;
335 	size_t key_len;
336 
337 	os_memset(isk, 0, isk_len);
338 
339 	if (data->phase2_method == NULL || data->phase2_priv == NULL) {
340 		wpa_printf(MSG_DEBUG, "EAP-FAST: Phase 2 method not "
341 			   "available");
342 		return -1;
343 	}
344 
345 	if (data->phase2_method->getKey == NULL)
346 		return 0;
347 
348 	if ((key = data->phase2_method->getKey(sm, data->phase2_priv,
349 					       &key_len)) == NULL) {
350 		wpa_printf(MSG_DEBUG, "EAP-FAST: Could not get key material "
351 			   "from Phase 2");
352 		return -1;
353 	}
354 
355 	if (key_len > isk_len)
356 		key_len = isk_len;
357 	if (key_len == 32 &&
358 	    data->phase2_method->vendor == EAP_VENDOR_IETF &&
359 	    data->phase2_method->method == EAP_TYPE_MSCHAPV2) {
360 		/*
361 		 * EAP-FAST uses reverse order for MS-MPPE keys when deriving
362 		 * MSK from EAP-MSCHAPv2. Swap the keys here to get the correct
363 		 * ISK for EAP-FAST cryptobinding.
364 		 */
365 		os_memcpy(isk, key + 16, 16);
366 		os_memcpy(isk + 16, key, 16);
367 	} else
368 		os_memcpy(isk, key, key_len);
369 	os_free(key);
370 
371 	return 0;
372 }
373 
374 
eap_fast_update_icmk(struct eap_sm * sm,struct eap_fast_data * data)375 static int eap_fast_update_icmk(struct eap_sm *sm, struct eap_fast_data *data)
376 {
377 	u8 isk[32], imck[60];
378 
379 	wpa_printf(MSG_DEBUG, "EAP-FAST: Deriving ICMK[%d] (S-IMCK and CMK)",
380 		   data->simck_idx + 1);
381 
382 	/*
383 	 * RFC 4851, Section 5.2:
384 	 * IMCK[j] = T-PRF(S-IMCK[j-1], "Inner Methods Compound Keys",
385 	 *                 MSK[j], 60)
386 	 * S-IMCK[j] = first 40 octets of IMCK[j]
387 	 * CMK[j] = last 20 octets of IMCK[j]
388 	 */
389 
390 	if (eap_fast_get_phase2_key(sm, data, isk, sizeof(isk)) < 0)
391 		return -1;
392 	wpa_hexdump_key(MSG_MSGDUMP, "EAP-FAST: ISK[j]", isk, sizeof(isk));
393 	sha1_t_prf(data->simck, EAP_FAST_SIMCK_LEN,
394 		   "Inner Methods Compound Keys",
395 		   isk, sizeof(isk), imck, sizeof(imck));
396 	data->simck_idx++;
397 	os_memcpy(data->simck, imck, EAP_FAST_SIMCK_LEN);
398 	wpa_hexdump_key(MSG_MSGDUMP, "EAP-FAST: S-IMCK[j]",
399 			data->simck, EAP_FAST_SIMCK_LEN);
400 	os_memcpy(data->cmk, imck + EAP_FAST_SIMCK_LEN, EAP_FAST_CMK_LEN);
401 	wpa_hexdump_key(MSG_MSGDUMP, "EAP-FAST: CMK[j]",
402 			data->cmk, EAP_FAST_CMK_LEN);
403 
404 	return 0;
405 }
406 
407 
eap_fast_init(struct eap_sm * sm)408 static void * eap_fast_init(struct eap_sm *sm)
409 {
410 	struct eap_fast_data *data;
411 	u8 ciphers[5] = {
412 		TLS_CIPHER_ANON_DH_AES128_SHA,
413 		TLS_CIPHER_AES128_SHA,
414 		TLS_CIPHER_RSA_DHE_AES128_SHA,
415 		TLS_CIPHER_RC4_SHA,
416 		TLS_CIPHER_NONE
417 	};
418 
419 	data = os_zalloc(sizeof(*data));
420 	if (data == NULL)
421 		return NULL;
422 	data->fast_version = EAP_FAST_VERSION;
423 	data->force_version = -1;
424 	if (sm->user && sm->user->force_version >= 0) {
425 		data->force_version = sm->user->force_version;
426 		wpa_printf(MSG_DEBUG, "EAP-FAST: forcing version %d",
427 			   data->force_version);
428 		data->fast_version = data->force_version;
429 	}
430 	data->state = START;
431 
432 	if (eap_server_tls_ssl_init(sm, &data->ssl, 0)) {
433 		wpa_printf(MSG_INFO, "EAP-FAST: Failed to initialize SSL.");
434 		eap_fast_reset(sm, data);
435 		return NULL;
436 	}
437 
438 	if (tls_connection_set_cipher_list(sm->ssl_ctx, data->ssl.conn,
439 					   ciphers) < 0) {
440 		wpa_printf(MSG_INFO, "EAP-FAST: Failed to set TLS cipher "
441 			   "suites");
442 		eap_fast_reset(sm, data);
443 		return NULL;
444 	}
445 
446 	if (tls_connection_set_session_ticket_cb(sm->ssl_ctx, data->ssl.conn,
447 						 eap_fast_session_ticket_cb,
448 						 data) < 0) {
449 		wpa_printf(MSG_INFO, "EAP-FAST: Failed to set SessionTicket "
450 			   "callback");
451 		eap_fast_reset(sm, data);
452 		return NULL;
453 	}
454 
455 	if (sm->pac_opaque_encr_key == NULL) {
456 		wpa_printf(MSG_INFO, "EAP-FAST: No PAC-Opaque encryption key "
457 			   "configured");
458 		eap_fast_reset(sm, data);
459 		return NULL;
460 	}
461 	os_memcpy(data->pac_opaque_encr, sm->pac_opaque_encr_key,
462 		  sizeof(data->pac_opaque_encr));
463 
464 	if (sm->eap_fast_a_id == NULL) {
465 		wpa_printf(MSG_INFO, "EAP-FAST: No A-ID configured");
466 		eap_fast_reset(sm, data);
467 		return NULL;
468 	}
469 	data->srv_id = os_malloc(sm->eap_fast_a_id_len);
470 	if (data->srv_id == NULL) {
471 		eap_fast_reset(sm, data);
472 		return NULL;
473 	}
474 	os_memcpy(data->srv_id, sm->eap_fast_a_id, sm->eap_fast_a_id_len);
475 	data->srv_id_len = sm->eap_fast_a_id_len;
476 
477 	if (sm->eap_fast_a_id_info == NULL) {
478 		wpa_printf(MSG_INFO, "EAP-FAST: No A-ID-Info configured");
479 		eap_fast_reset(sm, data);
480 		return NULL;
481 	}
482 	data->srv_id_info = os_strdup(sm->eap_fast_a_id_info);
483 	if (data->srv_id_info == NULL) {
484 		eap_fast_reset(sm, data);
485 		return NULL;
486 	}
487 
488 	/* PAC-Key lifetime in seconds (hard limit) */
489 	data->pac_key_lifetime = sm->pac_key_lifetime;
490 
491 	/*
492 	 * PAC-Key refresh time in seconds (soft limit on remaining hard
493 	 * limit). The server will generate a new PAC-Key when this number of
494 	 * seconds (or fewer) of the lifetime remains.
495 	 */
496 	data->pac_key_refresh_time = sm->pac_key_refresh_time;
497 
498 	return data;
499 }
500 
501 
eap_fast_reset(struct eap_sm * sm,void * priv)502 static void eap_fast_reset(struct eap_sm *sm, void *priv)
503 {
504 	struct eap_fast_data *data = priv;
505 	if (data == NULL)
506 		return;
507 	if (data->phase2_priv && data->phase2_method)
508 		data->phase2_method->reset(sm, data->phase2_priv);
509 	eap_server_tls_ssl_deinit(sm, &data->ssl);
510 	os_free(data->srv_id);
511 	os_free(data->srv_id_info);
512 	os_free(data->key_block_p);
513 	wpabuf_free(data->pending_phase2_resp);
514 	os_free(data->identity);
515 	bin_clear_free(data, sizeof(*data));
516 }
517 
518 
eap_fast_build_start(struct eap_sm * sm,struct eap_fast_data * data,u8 id)519 static struct wpabuf * eap_fast_build_start(struct eap_sm *sm,
520 					    struct eap_fast_data *data, u8 id)
521 {
522 	struct wpabuf *req;
523 
524 	req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_FAST,
525 			    1 + sizeof(struct pac_tlv_hdr) + data->srv_id_len,
526 			    EAP_CODE_REQUEST, id);
527 	if (req == NULL) {
528 		wpa_printf(MSG_ERROR, "EAP-FAST: Failed to allocate memory for"
529 			   " request");
530 		eap_fast_state(data, FAILURE);
531 		return NULL;
532 	}
533 
534 	wpabuf_put_u8(req, EAP_TLS_FLAGS_START | data->fast_version);
535 
536 	/* RFC 4851, 4.1.1. Authority ID Data */
537 	eap_fast_put_tlv(req, PAC_TYPE_A_ID, data->srv_id, data->srv_id_len);
538 
539 	eap_fast_state(data, PHASE1);
540 
541 	return req;
542 }
543 
544 
eap_fast_phase1_done(struct eap_sm * sm,struct eap_fast_data * data)545 static int eap_fast_phase1_done(struct eap_sm *sm, struct eap_fast_data *data)
546 {
547 	char cipher[64];
548 
549 	wpa_printf(MSG_DEBUG, "EAP-FAST: Phase1 done, starting Phase2");
550 
551 	if (tls_get_cipher(sm->ssl_ctx, data->ssl.conn, cipher, sizeof(cipher))
552 	    < 0) {
553 		wpa_printf(MSG_DEBUG, "EAP-FAST: Failed to get cipher "
554 			   "information");
555 		eap_fast_state(data, FAILURE);
556 		return -1;
557 	}
558 	data->anon_provisioning = os_strstr(cipher, "ADH") != NULL;
559 
560 	if (data->anon_provisioning) {
561 		wpa_printf(MSG_DEBUG, "EAP-FAST: Anonymous provisioning");
562 		eap_fast_derive_key_provisioning(sm, data);
563 	} else
564 		eap_fast_derive_key_auth(sm, data);
565 
566 	eap_fast_state(data, PHASE2_START);
567 
568 	return 0;
569 }
570 
571 
eap_fast_build_phase2_req(struct eap_sm * sm,struct eap_fast_data * data,u8 id)572 static struct wpabuf * eap_fast_build_phase2_req(struct eap_sm *sm,
573 						 struct eap_fast_data *data,
574 						 u8 id)
575 {
576 	struct wpabuf *req;
577 
578 	if (data->phase2_priv == NULL) {
579 		wpa_printf(MSG_DEBUG, "EAP-FAST: Phase 2 method not "
580 			   "initialized");
581 		return NULL;
582 	}
583 	req = data->phase2_method->buildReq(sm, data->phase2_priv, id);
584 	if (req == NULL)
585 		return NULL;
586 
587 	wpa_hexdump_buf_key(MSG_MSGDUMP, "EAP-FAST: Phase 2 EAP-Request", req);
588 	return eap_fast_tlv_eap_payload(req);
589 }
590 
591 
eap_fast_build_crypto_binding(struct eap_sm * sm,struct eap_fast_data * data)592 static struct wpabuf * eap_fast_build_crypto_binding(
593 	struct eap_sm *sm, struct eap_fast_data *data)
594 {
595 	struct wpabuf *buf;
596 	struct eap_tlv_result_tlv *result;
597 	struct eap_tlv_crypto_binding_tlv *binding;
598 
599 	buf = wpabuf_alloc(2 * sizeof(*result) + sizeof(*binding));
600 	if (buf == NULL)
601 		return NULL;
602 
603 	if (data->send_new_pac || data->anon_provisioning ||
604 	    data->phase2_method)
605 		data->final_result = 0;
606 	else
607 		data->final_result = 1;
608 
609 	if (!data->final_result || data->eap_seq > 1) {
610 		/* Intermediate-Result */
611 		wpa_printf(MSG_DEBUG, "EAP-FAST: Add Intermediate-Result TLV "
612 			   "(status=SUCCESS)");
613 		result = wpabuf_put(buf, sizeof(*result));
614 		result->tlv_type = host_to_be16(
615 			EAP_TLV_TYPE_MANDATORY |
616 			EAP_TLV_INTERMEDIATE_RESULT_TLV);
617 		result->length = host_to_be16(2);
618 		result->status = host_to_be16(EAP_TLV_RESULT_SUCCESS);
619 	}
620 
621 	if (data->final_result) {
622 		/* Result TLV */
623 		wpa_printf(MSG_DEBUG, "EAP-FAST: Add Result TLV "
624 			   "(status=SUCCESS)");
625 		result = wpabuf_put(buf, sizeof(*result));
626 		result->tlv_type = host_to_be16(EAP_TLV_TYPE_MANDATORY |
627 						EAP_TLV_RESULT_TLV);
628 		result->length = host_to_be16(2);
629 		result->status = host_to_be16(EAP_TLV_RESULT_SUCCESS);
630 	}
631 
632 	/* Crypto-Binding TLV */
633 	binding = wpabuf_put(buf, sizeof(*binding));
634 	binding->tlv_type = host_to_be16(EAP_TLV_TYPE_MANDATORY |
635 					 EAP_TLV_CRYPTO_BINDING_TLV);
636 	binding->length = host_to_be16(sizeof(*binding) -
637 				       sizeof(struct eap_tlv_hdr));
638 	binding->version = EAP_FAST_VERSION;
639 	binding->received_version = data->peer_version;
640 	binding->subtype = EAP_TLV_CRYPTO_BINDING_SUBTYPE_REQUEST;
641 	if (random_get_bytes(binding->nonce, sizeof(binding->nonce)) < 0) {
642 		wpabuf_free(buf);
643 		return NULL;
644 	}
645 
646 	/*
647 	 * RFC 4851, Section 4.2.8:
648 	 * The nonce in a request MUST have its least significant bit set to 0.
649 	 */
650 	binding->nonce[sizeof(binding->nonce) - 1] &= ~0x01;
651 
652 	os_memcpy(data->crypto_binding_nonce, binding->nonce,
653 		  sizeof(binding->nonce));
654 
655 	/*
656 	 * RFC 4851, Section 5.3:
657 	 * CMK = CMK[j]
658 	 * Compound-MAC = HMAC-SHA1( CMK, Crypto-Binding TLV )
659 	 */
660 
661 	hmac_sha1(data->cmk, EAP_FAST_CMK_LEN,
662 		  (u8 *) binding, sizeof(*binding),
663 		  binding->compound_mac);
664 
665 	wpa_printf(MSG_DEBUG, "EAP-FAST: Add Crypto-Binding TLV: Version %d "
666 		   "Received Version %d SubType %d",
667 		   binding->version, binding->received_version,
668 		   binding->subtype);
669 	wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: NONCE",
670 		    binding->nonce, sizeof(binding->nonce));
671 	wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: Compound MAC",
672 		    binding->compound_mac, sizeof(binding->compound_mac));
673 
674 	return buf;
675 }
676 
677 
eap_fast_build_pac(struct eap_sm * sm,struct eap_fast_data * data)678 static struct wpabuf * eap_fast_build_pac(struct eap_sm *sm,
679 					  struct eap_fast_data *data)
680 {
681 	u8 pac_key[EAP_FAST_PAC_KEY_LEN];
682 	u8 *pac_buf, *pac_opaque;
683 	struct wpabuf *buf;
684 	u8 *pos;
685 	size_t buf_len, srv_id_info_len, pac_len;
686 	struct eap_tlv_hdr *pac_tlv;
687 	struct pac_tlv_hdr *pac_info;
688 	struct eap_tlv_result_tlv *result;
689 	struct os_time now;
690 
691 	if (random_get_bytes(pac_key, EAP_FAST_PAC_KEY_LEN) < 0 ||
692 	    os_get_time(&now) < 0)
693 		return NULL;
694 	wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: Generated PAC-Key",
695 			pac_key, EAP_FAST_PAC_KEY_LEN);
696 
697 	pac_len = (2 + EAP_FAST_PAC_KEY_LEN) + (2 + 4) +
698 		(2 + sm->identity_len) + 8;
699 	pac_buf = os_malloc(pac_len);
700 	if (pac_buf == NULL)
701 		return NULL;
702 
703 	srv_id_info_len = os_strlen(data->srv_id_info);
704 
705 	pos = pac_buf;
706 	*pos++ = PAC_OPAQUE_TYPE_KEY;
707 	*pos++ = EAP_FAST_PAC_KEY_LEN;
708 	os_memcpy(pos, pac_key, EAP_FAST_PAC_KEY_LEN);
709 	pos += EAP_FAST_PAC_KEY_LEN;
710 
711 	*pos++ = PAC_OPAQUE_TYPE_LIFETIME;
712 	*pos++ = 4;
713 	WPA_PUT_BE32(pos, now.sec + data->pac_key_lifetime);
714 	pos += 4;
715 
716 	if (sm->identity) {
717 		*pos++ = PAC_OPAQUE_TYPE_IDENTITY;
718 		*pos++ = sm->identity_len;
719 		os_memcpy(pos, sm->identity, sm->identity_len);
720 		pos += sm->identity_len;
721 	}
722 
723 	pac_len = pos - pac_buf;
724 	while (pac_len % 8) {
725 		*pos++ = PAC_OPAQUE_TYPE_PAD;
726 		pac_len++;
727 	}
728 
729 	pac_opaque = os_malloc(pac_len + 8);
730 	if (pac_opaque == NULL) {
731 		os_free(pac_buf);
732 		return NULL;
733 	}
734 	if (aes_wrap(data->pac_opaque_encr, pac_len / 8, pac_buf,
735 		     pac_opaque) < 0) {
736 		os_free(pac_buf);
737 		os_free(pac_opaque);
738 		return NULL;
739 	}
740 	os_free(pac_buf);
741 
742 	pac_len += 8;
743 	wpa_hexdump(MSG_DEBUG, "EAP-FAST: PAC-Opaque",
744 		    pac_opaque, pac_len);
745 
746 	buf_len = sizeof(*pac_tlv) +
747 		sizeof(struct pac_tlv_hdr) + EAP_FAST_PAC_KEY_LEN +
748 		sizeof(struct pac_tlv_hdr) + pac_len +
749 		data->srv_id_len + srv_id_info_len + 100 + sizeof(*result);
750 	buf = wpabuf_alloc(buf_len);
751 	if (buf == NULL) {
752 		os_free(pac_opaque);
753 		return NULL;
754 	}
755 
756 	/* Result TLV */
757 	wpa_printf(MSG_DEBUG, "EAP-FAST: Add Result TLV (status=SUCCESS)");
758 	result = wpabuf_put(buf, sizeof(*result));
759 	WPA_PUT_BE16((u8 *) &result->tlv_type,
760 		     EAP_TLV_TYPE_MANDATORY | EAP_TLV_RESULT_TLV);
761 	WPA_PUT_BE16((u8 *) &result->length, 2);
762 	WPA_PUT_BE16((u8 *) &result->status, EAP_TLV_RESULT_SUCCESS);
763 
764 	/* PAC TLV */
765 	wpa_printf(MSG_DEBUG, "EAP-FAST: Add PAC TLV");
766 	pac_tlv = wpabuf_put(buf, sizeof(*pac_tlv));
767 	pac_tlv->tlv_type = host_to_be16(EAP_TLV_TYPE_MANDATORY |
768 					 EAP_TLV_PAC_TLV);
769 
770 	/* PAC-Key */
771 	eap_fast_put_tlv(buf, PAC_TYPE_PAC_KEY, pac_key, EAP_FAST_PAC_KEY_LEN);
772 
773 	/* PAC-Opaque */
774 	eap_fast_put_tlv(buf, PAC_TYPE_PAC_OPAQUE, pac_opaque, pac_len);
775 	os_free(pac_opaque);
776 
777 	/* PAC-Info */
778 	pac_info = wpabuf_put(buf, sizeof(*pac_info));
779 	pac_info->type = host_to_be16(PAC_TYPE_PAC_INFO);
780 
781 	/* PAC-Lifetime (inside PAC-Info) */
782 	eap_fast_put_tlv_hdr(buf, PAC_TYPE_CRED_LIFETIME, 4);
783 	wpabuf_put_be32(buf, now.sec + data->pac_key_lifetime);
784 
785 	/* A-ID (inside PAC-Info) */
786 	eap_fast_put_tlv(buf, PAC_TYPE_A_ID, data->srv_id, data->srv_id_len);
787 
788 	/* Note: headers may be misaligned after A-ID */
789 
790 	if (sm->identity) {
791 		eap_fast_put_tlv(buf, PAC_TYPE_I_ID, sm->identity,
792 				 sm->identity_len);
793 	}
794 
795 	/* A-ID-Info (inside PAC-Info) */
796 	eap_fast_put_tlv(buf, PAC_TYPE_A_ID_INFO, data->srv_id_info,
797 			 srv_id_info_len);
798 
799 	/* PAC-Type (inside PAC-Info) */
800 	eap_fast_put_tlv_hdr(buf, PAC_TYPE_PAC_TYPE, 2);
801 	wpabuf_put_be16(buf, PAC_TYPE_TUNNEL_PAC);
802 
803 	/* Update PAC-Info and PAC TLV Length fields */
804 	pos = wpabuf_put(buf, 0);
805 	pac_info->len = host_to_be16(pos - (u8 *) (pac_info + 1));
806 	pac_tlv->length = host_to_be16(pos - (u8 *) (pac_tlv + 1));
807 
808 	return buf;
809 }
810 
811 
eap_fast_encrypt_phase2(struct eap_sm * sm,struct eap_fast_data * data,struct wpabuf * plain,int piggyback)812 static int eap_fast_encrypt_phase2(struct eap_sm *sm,
813 				   struct eap_fast_data *data,
814 				   struct wpabuf *plain, int piggyback)
815 {
816 	struct wpabuf *encr;
817 
818 	wpa_hexdump_buf_key(MSG_DEBUG, "EAP-FAST: Encrypting Phase 2 TLVs",
819 			    plain);
820 	encr = eap_server_tls_encrypt(sm, &data->ssl, plain);
821 	wpabuf_free(plain);
822 
823 	if (data->ssl.tls_out && piggyback) {
824 		wpa_printf(MSG_DEBUG, "EAP-FAST: Piggyback Phase 2 data "
825 			   "(len=%d) with last Phase 1 Message (len=%d "
826 			   "used=%d)",
827 			   (int) wpabuf_len(encr),
828 			   (int) wpabuf_len(data->ssl.tls_out),
829 			   (int) data->ssl.tls_out_pos);
830 		if (wpabuf_resize(&data->ssl.tls_out, wpabuf_len(encr)) < 0) {
831 			wpa_printf(MSG_WARNING, "EAP-FAST: Failed to resize "
832 				   "output buffer");
833 			wpabuf_free(encr);
834 			return -1;
835 		}
836 		wpabuf_put_buf(data->ssl.tls_out, encr);
837 		wpabuf_free(encr);
838 	} else {
839 		wpabuf_free(data->ssl.tls_out);
840 		data->ssl.tls_out_pos = 0;
841 		data->ssl.tls_out = encr;
842 	}
843 
844 	return 0;
845 }
846 
847 
eap_fast_buildReq(struct eap_sm * sm,void * priv,u8 id)848 static struct wpabuf * eap_fast_buildReq(struct eap_sm *sm, void *priv, u8 id)
849 {
850 	struct eap_fast_data *data = priv;
851 	struct wpabuf *req = NULL;
852 	int piggyback = 0;
853 
854 	if (data->ssl.state == FRAG_ACK) {
855 		return eap_server_tls_build_ack(id, EAP_TYPE_FAST,
856 						data->fast_version);
857 	}
858 
859 	if (data->ssl.state == WAIT_FRAG_ACK) {
860 		return eap_server_tls_build_msg(&data->ssl, EAP_TYPE_FAST,
861 						data->fast_version, id);
862 	}
863 
864 	switch (data->state) {
865 	case START:
866 		return eap_fast_build_start(sm, data, id);
867 	case PHASE1:
868 		if (tls_connection_established(sm->ssl_ctx, data->ssl.conn)) {
869 			if (eap_fast_phase1_done(sm, data) < 0)
870 				return NULL;
871 			if (data->state == PHASE2_START) {
872 				/*
873 				 * Try to generate Phase 2 data to piggyback
874 				 * with the end of Phase 1 to avoid extra
875 				 * roundtrip.
876 				 */
877 				wpa_printf(MSG_DEBUG, "EAP-FAST: Try to start "
878 					   "Phase 2");
879 				if (eap_fast_process_phase2_start(sm, data))
880 					break;
881 				req = eap_fast_build_phase2_req(sm, data, id);
882 				piggyback = 1;
883 			}
884 		}
885 		break;
886 	case PHASE2_ID:
887 	case PHASE2_METHOD:
888 		req = eap_fast_build_phase2_req(sm, data, id);
889 		break;
890 	case CRYPTO_BINDING:
891 		req = eap_fast_build_crypto_binding(sm, data);
892 		if (data->phase2_method) {
893 			/*
894 			 * Include the start of the next EAP method in the
895 			 * sequence in the same message with Crypto-Binding to
896 			 * save a round-trip.
897 			 */
898 			struct wpabuf *eap;
899 			eap = eap_fast_build_phase2_req(sm, data, id);
900 			req = wpabuf_concat(req, eap);
901 			eap_fast_state(data, PHASE2_METHOD);
902 		}
903 		break;
904 	case REQUEST_PAC:
905 		req = eap_fast_build_pac(sm, data);
906 		break;
907 	default:
908 		wpa_printf(MSG_DEBUG, "EAP-FAST: %s - unexpected state %d",
909 			   __func__, data->state);
910 		return NULL;
911 	}
912 
913 	if (req &&
914 	    eap_fast_encrypt_phase2(sm, data, req, piggyback) < 0)
915 		return NULL;
916 
917 	return eap_server_tls_build_msg(&data->ssl, EAP_TYPE_FAST,
918 					data->fast_version, id);
919 }
920 
921 
eap_fast_check(struct eap_sm * sm,void * priv,struct wpabuf * respData)922 static Boolean eap_fast_check(struct eap_sm *sm, void *priv,
923 			      struct wpabuf *respData)
924 {
925 	const u8 *pos;
926 	size_t len;
927 
928 	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_FAST, respData, &len);
929 	if (pos == NULL || len < 1) {
930 		wpa_printf(MSG_INFO, "EAP-FAST: Invalid frame");
931 		return TRUE;
932 	}
933 
934 	return FALSE;
935 }
936 
937 
eap_fast_phase2_init(struct eap_sm * sm,struct eap_fast_data * data,EapType eap_type)938 static int eap_fast_phase2_init(struct eap_sm *sm, struct eap_fast_data *data,
939 				EapType eap_type)
940 {
941 	if (data->phase2_priv && data->phase2_method) {
942 		data->phase2_method->reset(sm, data->phase2_priv);
943 		data->phase2_method = NULL;
944 		data->phase2_priv = NULL;
945 	}
946 	data->phase2_method = eap_server_get_eap_method(EAP_VENDOR_IETF,
947 							eap_type);
948 	if (!data->phase2_method)
949 		return -1;
950 
951 	if (data->key_block_p) {
952 		sm->auth_challenge = data->key_block_p->server_challenge;
953 		sm->peer_challenge = data->key_block_p->client_challenge;
954 	}
955 	sm->init_phase2 = 1;
956 	data->phase2_priv = data->phase2_method->init(sm);
957 	sm->init_phase2 = 0;
958 	sm->auth_challenge = NULL;
959 	sm->peer_challenge = NULL;
960 
961 	return data->phase2_priv == NULL ? -1 : 0;
962 }
963 
964 
eap_fast_process_phase2_response(struct eap_sm * sm,struct eap_fast_data * data,u8 * in_data,size_t in_len)965 static void eap_fast_process_phase2_response(struct eap_sm *sm,
966 					     struct eap_fast_data *data,
967 					     u8 *in_data, size_t in_len)
968 {
969 	u8 next_type = EAP_TYPE_NONE;
970 	struct eap_hdr *hdr;
971 	u8 *pos;
972 	size_t left;
973 	struct wpabuf buf;
974 	const struct eap_method *m = data->phase2_method;
975 	void *priv = data->phase2_priv;
976 
977 	if (priv == NULL) {
978 		wpa_printf(MSG_DEBUG, "EAP-FAST: %s - Phase2 not "
979 			   "initialized?!", __func__);
980 		return;
981 	}
982 
983 	hdr = (struct eap_hdr *) in_data;
984 	pos = (u8 *) (hdr + 1);
985 
986 	if (in_len > sizeof(*hdr) && *pos == EAP_TYPE_NAK) {
987 		left = in_len - sizeof(*hdr);
988 		wpa_hexdump(MSG_DEBUG, "EAP-FAST: Phase2 type Nak'ed; "
989 			    "allowed types", pos + 1, left - 1);
990 #ifdef EAP_SERVER_TNC
991 		if (m && m->vendor == EAP_VENDOR_IETF &&
992 		    m->method == EAP_TYPE_TNC) {
993 			wpa_printf(MSG_DEBUG, "EAP-FAST: Peer Nak'ed required "
994 				   "TNC negotiation");
995 			next_type = eap_fast_req_failure(sm, data);
996 			eap_fast_phase2_init(sm, data, next_type);
997 			return;
998 		}
999 #endif /* EAP_SERVER_TNC */
1000 		eap_sm_process_nak(sm, pos + 1, left - 1);
1001 		if (sm->user && sm->user_eap_method_index < EAP_MAX_METHODS &&
1002 		    sm->user->methods[sm->user_eap_method_index].method !=
1003 		    EAP_TYPE_NONE) {
1004 			next_type = sm->user->methods[
1005 				sm->user_eap_method_index++].method;
1006 			wpa_printf(MSG_DEBUG, "EAP-FAST: try EAP type %d",
1007 				   next_type);
1008 		} else {
1009 			next_type = eap_fast_req_failure(sm, data);
1010 		}
1011 		eap_fast_phase2_init(sm, data, next_type);
1012 		return;
1013 	}
1014 
1015 	wpabuf_set(&buf, in_data, in_len);
1016 
1017 	if (m->check(sm, priv, &buf)) {
1018 		wpa_printf(MSG_DEBUG, "EAP-FAST: Phase2 check() asked to "
1019 			   "ignore the packet");
1020 		next_type = eap_fast_req_failure(sm, data);
1021 		return;
1022 	}
1023 
1024 	m->process(sm, priv, &buf);
1025 
1026 	if (!m->isDone(sm, priv))
1027 		return;
1028 
1029 	if (!m->isSuccess(sm, priv)) {
1030 		wpa_printf(MSG_DEBUG, "EAP-FAST: Phase2 method failed");
1031 		next_type = eap_fast_req_failure(sm, data);
1032 		eap_fast_phase2_init(sm, data, next_type);
1033 		return;
1034 	}
1035 
1036 	switch (data->state) {
1037 	case PHASE2_ID:
1038 		if (eap_user_get(sm, sm->identity, sm->identity_len, 1) != 0) {
1039 			wpa_hexdump_ascii(MSG_DEBUG, "EAP-FAST: Phase2 "
1040 					  "Identity not found in the user "
1041 					  "database",
1042 					  sm->identity, sm->identity_len);
1043 			next_type = eap_fast_req_failure(sm, data);
1044 			break;
1045 		}
1046 
1047 		eap_fast_state(data, PHASE2_METHOD);
1048 		if (data->anon_provisioning) {
1049 			/*
1050 			 * Only EAP-MSCHAPv2 is allowed for anonymous
1051 			 * provisioning.
1052 			 */
1053 			next_type = EAP_TYPE_MSCHAPV2;
1054 			sm->user_eap_method_index = 0;
1055 		} else {
1056 			next_type = sm->user->methods[0].method;
1057 			sm->user_eap_method_index = 1;
1058 		}
1059 		wpa_printf(MSG_DEBUG, "EAP-FAST: try EAP type %d", next_type);
1060 		break;
1061 	case PHASE2_METHOD:
1062 	case CRYPTO_BINDING:
1063 		eap_fast_update_icmk(sm, data);
1064 		eap_fast_state(data, CRYPTO_BINDING);
1065 		data->eap_seq++;
1066 		next_type = EAP_TYPE_NONE;
1067 #ifdef EAP_SERVER_TNC
1068 		if (sm->tnc && !data->tnc_started) {
1069 			wpa_printf(MSG_DEBUG, "EAP-FAST: Initialize TNC");
1070 			next_type = EAP_TYPE_TNC;
1071 			data->tnc_started = 1;
1072 		}
1073 #endif /* EAP_SERVER_TNC */
1074 		break;
1075 	case FAILURE:
1076 		break;
1077 	default:
1078 		wpa_printf(MSG_DEBUG, "EAP-FAST: %s - unexpected state %d",
1079 			   __func__, data->state);
1080 		break;
1081 	}
1082 
1083 	eap_fast_phase2_init(sm, data, next_type);
1084 }
1085 
1086 
eap_fast_process_phase2_eap(struct eap_sm * sm,struct eap_fast_data * data,u8 * in_data,size_t in_len)1087 static void eap_fast_process_phase2_eap(struct eap_sm *sm,
1088 					struct eap_fast_data *data,
1089 					u8 *in_data, size_t in_len)
1090 {
1091 	struct eap_hdr *hdr;
1092 	size_t len;
1093 
1094 	hdr = (struct eap_hdr *) in_data;
1095 	if (in_len < (int) sizeof(*hdr)) {
1096 		wpa_printf(MSG_INFO, "EAP-FAST: Too short Phase 2 "
1097 			   "EAP frame (len=%lu)", (unsigned long) in_len);
1098 		eap_fast_req_failure(sm, data);
1099 		return;
1100 	}
1101 	len = be_to_host16(hdr->length);
1102 	if (len > in_len) {
1103 		wpa_printf(MSG_INFO, "EAP-FAST: Length mismatch in "
1104 			   "Phase 2 EAP frame (len=%lu hdr->length=%lu)",
1105 			   (unsigned long) in_len, (unsigned long) len);
1106 		eap_fast_req_failure(sm, data);
1107 		return;
1108 	}
1109 	wpa_printf(MSG_DEBUG, "EAP-FAST: Received Phase 2: code=%d "
1110 		   "identifier=%d length=%lu", hdr->code, hdr->identifier,
1111 		   (unsigned long) len);
1112 	switch (hdr->code) {
1113 	case EAP_CODE_RESPONSE:
1114 		eap_fast_process_phase2_response(sm, data, (u8 *) hdr, len);
1115 		break;
1116 	default:
1117 		wpa_printf(MSG_INFO, "EAP-FAST: Unexpected code=%d in "
1118 			   "Phase 2 EAP header", hdr->code);
1119 		break;
1120 	}
1121 }
1122 
1123 
eap_fast_parse_tlvs(struct wpabuf * data,struct eap_fast_tlv_parse * tlv)1124 static int eap_fast_parse_tlvs(struct wpabuf *data,
1125 			       struct eap_fast_tlv_parse *tlv)
1126 {
1127 	int mandatory, tlv_type, res;
1128 	size_t len;
1129 	u8 *pos, *end;
1130 
1131 	os_memset(tlv, 0, sizeof(*tlv));
1132 
1133 	pos = wpabuf_mhead(data);
1134 	end = pos + wpabuf_len(data);
1135 	while (pos + 4 < end) {
1136 		mandatory = pos[0] & 0x80;
1137 		tlv_type = WPA_GET_BE16(pos) & 0x3fff;
1138 		pos += 2;
1139 		len = WPA_GET_BE16(pos);
1140 		pos += 2;
1141 		if (len > (size_t) (end - pos)) {
1142 			wpa_printf(MSG_INFO, "EAP-FAST: TLV overflow");
1143 			return -1;
1144 		}
1145 		wpa_printf(MSG_DEBUG, "EAP-FAST: Received Phase 2: "
1146 			   "TLV type %d length %u%s",
1147 			   tlv_type, (unsigned int) len,
1148 			   mandatory ? " (mandatory)" : "");
1149 
1150 		res = eap_fast_parse_tlv(tlv, tlv_type, pos, len);
1151 		if (res == -2)
1152 			break;
1153 		if (res < 0) {
1154 			if (mandatory) {
1155 				wpa_printf(MSG_DEBUG, "EAP-FAST: Nak unknown "
1156 					   "mandatory TLV type %d", tlv_type);
1157 				/* TODO: generate Nak TLV */
1158 				break;
1159 			} else {
1160 				wpa_printf(MSG_DEBUG, "EAP-FAST: Ignored "
1161 					   "unknown optional TLV type %d",
1162 					   tlv_type);
1163 			}
1164 		}
1165 
1166 		pos += len;
1167 	}
1168 
1169 	return 0;
1170 }
1171 
1172 
eap_fast_validate_crypto_binding(struct eap_fast_data * data,struct eap_tlv_crypto_binding_tlv * b,size_t bind_len)1173 static int eap_fast_validate_crypto_binding(
1174 	struct eap_fast_data *data, struct eap_tlv_crypto_binding_tlv *b,
1175 	size_t bind_len)
1176 {
1177 	u8 cmac[SHA1_MAC_LEN];
1178 
1179 	wpa_printf(MSG_DEBUG, "EAP-FAST: Reply Crypto-Binding TLV: "
1180 		   "Version %d Received Version %d SubType %d",
1181 		   b->version, b->received_version, b->subtype);
1182 	wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: NONCE",
1183 		    b->nonce, sizeof(b->nonce));
1184 	wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: Compound MAC",
1185 		    b->compound_mac, sizeof(b->compound_mac));
1186 
1187 	if (b->version != EAP_FAST_VERSION ||
1188 	    b->received_version != EAP_FAST_VERSION) {
1189 		wpa_printf(MSG_DEBUG, "EAP-FAST: Unexpected version "
1190 			   "in Crypto-Binding: version %d "
1191 			   "received_version %d", b->version,
1192 			   b->received_version);
1193 		return -1;
1194 	}
1195 
1196 	if (b->subtype != EAP_TLV_CRYPTO_BINDING_SUBTYPE_RESPONSE) {
1197 		wpa_printf(MSG_DEBUG, "EAP-FAST: Unexpected subtype in "
1198 			   "Crypto-Binding: %d", b->subtype);
1199 		return -1;
1200 	}
1201 
1202 	if (os_memcmp_const(data->crypto_binding_nonce, b->nonce, 31) != 0 ||
1203 	    (data->crypto_binding_nonce[31] | 1) != b->nonce[31]) {
1204 		wpa_printf(MSG_DEBUG, "EAP-FAST: Invalid nonce in "
1205 			   "Crypto-Binding");
1206 		return -1;
1207 	}
1208 
1209 	os_memcpy(cmac, b->compound_mac, sizeof(cmac));
1210 	os_memset(b->compound_mac, 0, sizeof(cmac));
1211 	wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: Crypto-Binding TLV for "
1212 		    "Compound MAC calculation",
1213 		    (u8 *) b, bind_len);
1214 	hmac_sha1(data->cmk, EAP_FAST_CMK_LEN, (u8 *) b, bind_len,
1215 		  b->compound_mac);
1216 	if (os_memcmp_const(cmac, b->compound_mac, sizeof(cmac)) != 0) {
1217 		wpa_hexdump(MSG_MSGDUMP,
1218 			    "EAP-FAST: Calculated Compound MAC",
1219 			    b->compound_mac, sizeof(cmac));
1220 		wpa_printf(MSG_INFO, "EAP-FAST: Compound MAC did not "
1221 			   "match");
1222 		return -1;
1223 	}
1224 
1225 	return 0;
1226 }
1227 
1228 
eap_fast_pac_type(u8 * pac,size_t len,u16 type)1229 static int eap_fast_pac_type(u8 *pac, size_t len, u16 type)
1230 {
1231 	struct eap_tlv_pac_type_tlv *tlv;
1232 
1233 	if (pac == NULL || len != sizeof(*tlv))
1234 		return 0;
1235 
1236 	tlv = (struct eap_tlv_pac_type_tlv *) pac;
1237 
1238 	return be_to_host16(tlv->tlv_type) == PAC_TYPE_PAC_TYPE &&
1239 		be_to_host16(tlv->length) == 2 &&
1240 		be_to_host16(tlv->pac_type) == type;
1241 }
1242 
1243 
eap_fast_process_phase2_tlvs(struct eap_sm * sm,struct eap_fast_data * data,struct wpabuf * in_data)1244 static void eap_fast_process_phase2_tlvs(struct eap_sm *sm,
1245 					 struct eap_fast_data *data,
1246 					 struct wpabuf *in_data)
1247 {
1248 	struct eap_fast_tlv_parse tlv;
1249 	int check_crypto_binding = data->state == CRYPTO_BINDING;
1250 
1251 	if (eap_fast_parse_tlvs(in_data, &tlv) < 0) {
1252 		wpa_printf(MSG_DEBUG, "EAP-FAST: Failed to parse received "
1253 			   "Phase 2 TLVs");
1254 		return;
1255 	}
1256 
1257 	if (tlv.result == EAP_TLV_RESULT_FAILURE) {
1258 		wpa_printf(MSG_DEBUG, "EAP-FAST: Result TLV indicated "
1259 			   "failure");
1260 		eap_fast_state(data, FAILURE);
1261 		return;
1262 	}
1263 
1264 	if (data->state == REQUEST_PAC) {
1265 		u16 type, len, res;
1266 		if (tlv.pac == NULL || tlv.pac_len < 6) {
1267 			wpa_printf(MSG_DEBUG, "EAP-FAST: No PAC "
1268 				   "Acknowledgement received");
1269 			eap_fast_state(data, FAILURE);
1270 			return;
1271 		}
1272 
1273 		type = WPA_GET_BE16(tlv.pac);
1274 		len = WPA_GET_BE16(tlv.pac + 2);
1275 		res = WPA_GET_BE16(tlv.pac + 4);
1276 
1277 		if (type != PAC_TYPE_PAC_ACKNOWLEDGEMENT || len != 2 ||
1278 		    res != EAP_TLV_RESULT_SUCCESS) {
1279 			wpa_printf(MSG_DEBUG, "EAP-FAST: PAC TLV did not "
1280 				   "contain acknowledgement");
1281 			eap_fast_state(data, FAILURE);
1282 			return;
1283 		}
1284 
1285 		wpa_printf(MSG_DEBUG, "EAP-FAST: PAC-Acknowledgement received "
1286 			   "- PAC provisioning succeeded");
1287 		eap_fast_state(data, (data->anon_provisioning ||
1288 				      data->send_new_pac == 2) ?
1289 			       FAILURE : SUCCESS);
1290 		return;
1291 	}
1292 
1293 	if (check_crypto_binding) {
1294 		if (tlv.crypto_binding == NULL) {
1295 			wpa_printf(MSG_DEBUG, "EAP-FAST: No Crypto-Binding "
1296 				   "TLV received");
1297 			eap_fast_state(data, FAILURE);
1298 			return;
1299 		}
1300 
1301 		if (data->final_result &&
1302 		    tlv.result != EAP_TLV_RESULT_SUCCESS) {
1303 			wpa_printf(MSG_DEBUG, "EAP-FAST: Crypto-Binding TLV "
1304 				   "without Success Result");
1305 			eap_fast_state(data, FAILURE);
1306 			return;
1307 		}
1308 
1309 		if (!data->final_result &&
1310 		    tlv.iresult != EAP_TLV_RESULT_SUCCESS) {
1311 			wpa_printf(MSG_DEBUG, "EAP-FAST: Crypto-Binding TLV "
1312 				   "without intermediate Success Result");
1313 			eap_fast_state(data, FAILURE);
1314 			return;
1315 		}
1316 
1317 		if (eap_fast_validate_crypto_binding(data, tlv.crypto_binding,
1318 						     tlv.crypto_binding_len)) {
1319 			eap_fast_state(data, FAILURE);
1320 			return;
1321 		}
1322 
1323 		wpa_printf(MSG_DEBUG, "EAP-FAST: Valid Crypto-Binding TLV "
1324 			   "received");
1325 		if (data->final_result) {
1326 			wpa_printf(MSG_DEBUG, "EAP-FAST: Authentication "
1327 				   "completed successfully");
1328 		}
1329 
1330 		if (data->anon_provisioning &&
1331 		    sm->eap_fast_prov != ANON_PROV &&
1332 		    sm->eap_fast_prov != BOTH_PROV) {
1333 			wpa_printf(MSG_DEBUG, "EAP-FAST: Client is trying to "
1334 				   "use unauthenticated provisioning which is "
1335 				   "disabled");
1336 			eap_fast_state(data, FAILURE);
1337 			return;
1338 		}
1339 
1340 		if (sm->eap_fast_prov != AUTH_PROV &&
1341 		    sm->eap_fast_prov != BOTH_PROV &&
1342 		    tlv.request_action == EAP_TLV_ACTION_PROCESS_TLV &&
1343 		    eap_fast_pac_type(tlv.pac, tlv.pac_len,
1344 				      PAC_TYPE_TUNNEL_PAC)) {
1345 			wpa_printf(MSG_DEBUG, "EAP-FAST: Client is trying to "
1346 				   "use authenticated provisioning which is "
1347 				   "disabled");
1348 			eap_fast_state(data, FAILURE);
1349 			return;
1350 		}
1351 
1352 		if (data->anon_provisioning ||
1353 		    (tlv.request_action == EAP_TLV_ACTION_PROCESS_TLV &&
1354 		     eap_fast_pac_type(tlv.pac, tlv.pac_len,
1355 				       PAC_TYPE_TUNNEL_PAC))) {
1356 			wpa_printf(MSG_DEBUG, "EAP-FAST: Requested a new "
1357 				   "Tunnel PAC");
1358 			eap_fast_state(data, REQUEST_PAC);
1359 		} else if (data->send_new_pac) {
1360 			wpa_printf(MSG_DEBUG, "EAP-FAST: Server triggered "
1361 				   "re-keying of Tunnel PAC");
1362 			eap_fast_state(data, REQUEST_PAC);
1363 		} else if (data->final_result)
1364 			eap_fast_state(data, SUCCESS);
1365 	}
1366 
1367 	if (tlv.eap_payload_tlv) {
1368 		eap_fast_process_phase2_eap(sm, data, tlv.eap_payload_tlv,
1369 					    tlv.eap_payload_tlv_len);
1370 	}
1371 }
1372 
1373 
eap_fast_process_phase2(struct eap_sm * sm,struct eap_fast_data * data,struct wpabuf * in_buf)1374 static void eap_fast_process_phase2(struct eap_sm *sm,
1375 				    struct eap_fast_data *data,
1376 				    struct wpabuf *in_buf)
1377 {
1378 	struct wpabuf *in_decrypted;
1379 
1380 	wpa_printf(MSG_DEBUG, "EAP-FAST: Received %lu bytes encrypted data for"
1381 		   " Phase 2", (unsigned long) wpabuf_len(in_buf));
1382 
1383 	if (data->pending_phase2_resp) {
1384 		wpa_printf(MSG_DEBUG, "EAP-PEAP: Pending Phase 2 response - "
1385 			   "skip decryption and use old data");
1386 		eap_fast_process_phase2_tlvs(sm, data,
1387 					     data->pending_phase2_resp);
1388 		wpabuf_free(data->pending_phase2_resp);
1389 		data->pending_phase2_resp = NULL;
1390 		return;
1391 	}
1392 
1393 	in_decrypted = tls_connection_decrypt(sm->ssl_ctx, data->ssl.conn,
1394 					      in_buf);
1395 	if (in_decrypted == NULL) {
1396 		wpa_printf(MSG_INFO, "EAP-FAST: Failed to decrypt Phase 2 "
1397 			   "data");
1398 		eap_fast_state(data, FAILURE);
1399 		return;
1400 	}
1401 
1402 	wpa_hexdump_buf_key(MSG_DEBUG, "EAP-FAST: Decrypted Phase 2 TLVs",
1403 			    in_decrypted);
1404 
1405 	eap_fast_process_phase2_tlvs(sm, data, in_decrypted);
1406 
1407 	if (sm->method_pending == METHOD_PENDING_WAIT) {
1408 		wpa_printf(MSG_DEBUG, "EAP-FAST: Phase2 method is in "
1409 			   "pending wait state - save decrypted response");
1410 		wpabuf_free(data->pending_phase2_resp);
1411 		data->pending_phase2_resp = in_decrypted;
1412 		return;
1413 	}
1414 
1415 	wpabuf_free(in_decrypted);
1416 }
1417 
1418 
eap_fast_process_version(struct eap_sm * sm,void * priv,int peer_version)1419 static int eap_fast_process_version(struct eap_sm *sm, void *priv,
1420 				    int peer_version)
1421 {
1422 	struct eap_fast_data *data = priv;
1423 
1424 	data->peer_version = peer_version;
1425 
1426 	if (data->force_version >= 0 && peer_version != data->force_version) {
1427 		wpa_printf(MSG_INFO, "EAP-FAST: peer did not select the forced"
1428 			   " version (forced=%d peer=%d) - reject",
1429 			   data->force_version, peer_version);
1430 		return -1;
1431 	}
1432 
1433 	if (peer_version < data->fast_version) {
1434 		wpa_printf(MSG_DEBUG, "EAP-FAST: peer ver=%d, own ver=%d; "
1435 			   "use version %d",
1436 			   peer_version, data->fast_version, peer_version);
1437 		data->fast_version = peer_version;
1438 	}
1439 
1440 	return 0;
1441 }
1442 
1443 
eap_fast_process_phase1(struct eap_sm * sm,struct eap_fast_data * data)1444 static int eap_fast_process_phase1(struct eap_sm *sm,
1445 				   struct eap_fast_data *data)
1446 {
1447 	if (eap_server_tls_phase1(sm, &data->ssl) < 0) {
1448 		wpa_printf(MSG_INFO, "EAP-FAST: TLS processing failed");
1449 		eap_fast_state(data, FAILURE);
1450 		return -1;
1451 	}
1452 
1453 	if (!tls_connection_established(sm->ssl_ctx, data->ssl.conn) ||
1454 	    wpabuf_len(data->ssl.tls_out) > 0)
1455 		return 1;
1456 
1457 	/*
1458 	 * Phase 1 was completed with the received message (e.g., when using
1459 	 * abbreviated handshake), so Phase 2 can be started immediately
1460 	 * without having to send through an empty message to the peer.
1461 	 */
1462 
1463 	return eap_fast_phase1_done(sm, data);
1464 }
1465 
1466 
eap_fast_process_phase2_start(struct eap_sm * sm,struct eap_fast_data * data)1467 static int eap_fast_process_phase2_start(struct eap_sm *sm,
1468 					 struct eap_fast_data *data)
1469 {
1470 	u8 next_type;
1471 
1472 	if (data->identity) {
1473 		os_free(sm->identity);
1474 		sm->identity = data->identity;
1475 		data->identity = NULL;
1476 		sm->identity_len = data->identity_len;
1477 		data->identity_len = 0;
1478 		sm->require_identity_match = 1;
1479 		if (eap_user_get(sm, sm->identity, sm->identity_len, 1) != 0) {
1480 			wpa_hexdump_ascii(MSG_DEBUG, "EAP-FAST: "
1481 					  "Phase2 Identity not found "
1482 					  "in the user database",
1483 					  sm->identity, sm->identity_len);
1484 			next_type = eap_fast_req_failure(sm, data);
1485 		} else {
1486 			wpa_printf(MSG_DEBUG, "EAP-FAST: Identity already "
1487 				   "known - skip Phase 2 Identity Request");
1488 			next_type = sm->user->methods[0].method;
1489 			sm->user_eap_method_index = 1;
1490 		}
1491 
1492 		eap_fast_state(data, PHASE2_METHOD);
1493 	} else {
1494 		eap_fast_state(data, PHASE2_ID);
1495 		next_type = EAP_TYPE_IDENTITY;
1496 	}
1497 
1498 	return eap_fast_phase2_init(sm, data, next_type);
1499 }
1500 
1501 
eap_fast_process_msg(struct eap_sm * sm,void * priv,const struct wpabuf * respData)1502 static void eap_fast_process_msg(struct eap_sm *sm, void *priv,
1503 				 const struct wpabuf *respData)
1504 {
1505 	struct eap_fast_data *data = priv;
1506 
1507 	switch (data->state) {
1508 	case PHASE1:
1509 		if (eap_fast_process_phase1(sm, data))
1510 			break;
1511 
1512 		/* fall through to PHASE2_START */
1513 	case PHASE2_START:
1514 		eap_fast_process_phase2_start(sm, data);
1515 		break;
1516 	case PHASE2_ID:
1517 	case PHASE2_METHOD:
1518 	case CRYPTO_BINDING:
1519 	case REQUEST_PAC:
1520 		eap_fast_process_phase2(sm, data, data->ssl.tls_in);
1521 		break;
1522 	default:
1523 		wpa_printf(MSG_DEBUG, "EAP-FAST: Unexpected state %d in %s",
1524 			   data->state, __func__);
1525 		break;
1526 	}
1527 }
1528 
1529 
eap_fast_process(struct eap_sm * sm,void * priv,struct wpabuf * respData)1530 static void eap_fast_process(struct eap_sm *sm, void *priv,
1531 			     struct wpabuf *respData)
1532 {
1533 	struct eap_fast_data *data = priv;
1534 	if (eap_server_tls_process(sm, &data->ssl, respData, data,
1535 				   EAP_TYPE_FAST, eap_fast_process_version,
1536 				   eap_fast_process_msg) < 0)
1537 		eap_fast_state(data, FAILURE);
1538 }
1539 
1540 
eap_fast_isDone(struct eap_sm * sm,void * priv)1541 static Boolean eap_fast_isDone(struct eap_sm *sm, void *priv)
1542 {
1543 	struct eap_fast_data *data = priv;
1544 	return data->state == SUCCESS || data->state == FAILURE;
1545 }
1546 
1547 
eap_fast_getKey(struct eap_sm * sm,void * priv,size_t * len)1548 static u8 * eap_fast_getKey(struct eap_sm *sm, void *priv, size_t *len)
1549 {
1550 	struct eap_fast_data *data = priv;
1551 	u8 *eapKeyData;
1552 
1553 	if (data->state != SUCCESS)
1554 		return NULL;
1555 
1556 	eapKeyData = os_malloc(EAP_FAST_KEY_LEN);
1557 	if (eapKeyData == NULL)
1558 		return NULL;
1559 
1560 	eap_fast_derive_eap_msk(data->simck, eapKeyData);
1561 	*len = EAP_FAST_KEY_LEN;
1562 
1563 	return eapKeyData;
1564 }
1565 
1566 
eap_fast_get_emsk(struct eap_sm * sm,void * priv,size_t * len)1567 static u8 * eap_fast_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
1568 {
1569 	struct eap_fast_data *data = priv;
1570 	u8 *eapKeyData;
1571 
1572 	if (data->state != SUCCESS)
1573 		return NULL;
1574 
1575 	eapKeyData = os_malloc(EAP_EMSK_LEN);
1576 	if (eapKeyData == NULL)
1577 		return NULL;
1578 
1579 	eap_fast_derive_eap_emsk(data->simck, eapKeyData);
1580 	*len = EAP_EMSK_LEN;
1581 
1582 	return eapKeyData;
1583 }
1584 
1585 
eap_fast_isSuccess(struct eap_sm * sm,void * priv)1586 static Boolean eap_fast_isSuccess(struct eap_sm *sm, void *priv)
1587 {
1588 	struct eap_fast_data *data = priv;
1589 	return data->state == SUCCESS;
1590 }
1591 
1592 
eap_server_fast_register(void)1593 int eap_server_fast_register(void)
1594 {
1595 	struct eap_method *eap;
1596 	int ret;
1597 
1598 	eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
1599 				      EAP_VENDOR_IETF, EAP_TYPE_FAST, "FAST");
1600 	if (eap == NULL)
1601 		return -1;
1602 
1603 	eap->init = eap_fast_init;
1604 	eap->reset = eap_fast_reset;
1605 	eap->buildReq = eap_fast_buildReq;
1606 	eap->check = eap_fast_check;
1607 	eap->process = eap_fast_process;
1608 	eap->isDone = eap_fast_isDone;
1609 	eap->getKey = eap_fast_getKey;
1610 	eap->get_emsk = eap_fast_get_emsk;
1611 	eap->isSuccess = eap_fast_isSuccess;
1612 
1613 	ret = eap_server_method_register(eap);
1614 	if (ret)
1615 		eap_server_method_free(eap);
1616 	return ret;
1617 }
1618