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1 /*
2  * TLSv1 client - write handshake message
3  * Copyright (c) 2006-2015, 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/md5.h"
13 #include "crypto/sha1.h"
14 #include "crypto/sha256.h"
15 #include "crypto/tls.h"
16 #include "crypto/random.h"
17 #include "x509v3.h"
18 #include "tlsv1_common.h"
19 #include "tlsv1_record.h"
20 #include "tlsv1_client.h"
21 #include "tlsv1_client_i.h"
22 
23 
tls_client_cert_chain_der_len(struct tlsv1_client * conn)24 static size_t tls_client_cert_chain_der_len(struct tlsv1_client *conn)
25 {
26 	size_t len = 0;
27 	struct x509_certificate *cert;
28 
29 	if (conn->cred == NULL)
30 		return 0;
31 
32 	cert = conn->cred->cert;
33 	while (cert) {
34 		len += 3 + cert->cert_len;
35 		if (x509_certificate_self_signed(cert))
36 			break;
37 		cert = x509_certificate_get_subject(conn->cred->trusted_certs,
38 						    &cert->issuer);
39 	}
40 
41 	return len;
42 }
43 
44 
tls_send_client_hello(struct tlsv1_client * conn,size_t * out_len)45 u8 * tls_send_client_hello(struct tlsv1_client *conn, size_t *out_len)
46 {
47 	u8 *hello, *end, *pos, *hs_length, *hs_start, *rhdr;
48 	struct os_time now;
49 	size_t len, i;
50 	u8 *ext_start;
51 	u16 tls_version = TLS_VERSION;
52 
53 	/* Pick the highest locally enabled TLS version */
54 #ifdef CONFIG_TLSV12
55 	if ((conn->flags & TLS_CONN_DISABLE_TLSv1_2) &&
56 	    tls_version == TLS_VERSION_1_2)
57 		tls_version = TLS_VERSION_1_1;
58 #endif /* CONFIG_TLSV12 */
59 #ifdef CONFIG_TLSV11
60 	if ((conn->flags & TLS_CONN_DISABLE_TLSv1_1) &&
61 	    tls_version == TLS_VERSION_1_1)
62 		tls_version = TLS_VERSION_1;
63 #endif /* CONFIG_TLSV11 */
64 	if ((conn->flags & TLS_CONN_DISABLE_TLSv1_0) &&
65 	    tls_version == TLS_VERSION_1) {
66 		wpa_printf(MSG_INFO, "TLSv1: No TLS version allowed");
67 		return NULL;
68 	}
69 
70 	wpa_printf(MSG_DEBUG, "TLSv1: Send ClientHello (ver %s)",
71 		   tls_version_str(tls_version));
72 	*out_len = 0;
73 
74 	os_get_time(&now);
75 	WPA_PUT_BE32(conn->client_random, now.sec);
76 	if (random_get_bytes(conn->client_random + 4, TLS_RANDOM_LEN - 4)) {
77 		wpa_printf(MSG_ERROR, "TLSv1: Could not generate "
78 			   "client_random");
79 		return NULL;
80 	}
81 	wpa_hexdump(MSG_MSGDUMP, "TLSv1: client_random",
82 		    conn->client_random, TLS_RANDOM_LEN);
83 
84 	len = 150 + conn->num_cipher_suites * 2 + conn->client_hello_ext_len;
85 	hello = os_malloc(len);
86 	if (hello == NULL)
87 		return NULL;
88 	end = hello + len;
89 
90 	rhdr = hello;
91 	pos = rhdr + TLS_RECORD_HEADER_LEN;
92 
93 	/* opaque fragment[TLSPlaintext.length] */
94 
95 	/* Handshake */
96 	hs_start = pos;
97 	/* HandshakeType msg_type */
98 	*pos++ = TLS_HANDSHAKE_TYPE_CLIENT_HELLO;
99 	/* uint24 length (to be filled) */
100 	hs_length = pos;
101 	pos += 3;
102 	/* body - ClientHello */
103 	/* ProtocolVersion client_version */
104 	WPA_PUT_BE16(pos, tls_version);
105 	pos += 2;
106 	/* Random random: uint32 gmt_unix_time, opaque random_bytes */
107 	os_memcpy(pos, conn->client_random, TLS_RANDOM_LEN);
108 	pos += TLS_RANDOM_LEN;
109 	/* SessionID session_id */
110 	*pos++ = conn->session_id_len;
111 	os_memcpy(pos, conn->session_id, conn->session_id_len);
112 	pos += conn->session_id_len;
113 	/* CipherSuite cipher_suites<2..2^16-1> */
114 	WPA_PUT_BE16(pos, 2 * conn->num_cipher_suites);
115 	pos += 2;
116 	for (i = 0; i < conn->num_cipher_suites; i++) {
117 		WPA_PUT_BE16(pos, conn->cipher_suites[i]);
118 		pos += 2;
119 	}
120 	/* CompressionMethod compression_methods<1..2^8-1> */
121 	*pos++ = 1;
122 	*pos++ = TLS_COMPRESSION_NULL;
123 
124 	/* Extension */
125 	ext_start = pos;
126 	pos += 2;
127 
128 #ifdef CONFIG_TLSV12
129 	if (conn->rl.tls_version >= TLS_VERSION_1_2) {
130 		/*
131 		 * Add signature_algorithms extension since we support only
132 		 * SHA256 (and not the default SHA1) with TLSv1.2.
133 		 */
134 		/* ExtensionsType extension_type = signature_algorithms(13) */
135 		WPA_PUT_BE16(pos, TLS_EXT_SIGNATURE_ALGORITHMS);
136 		pos += 2;
137 		/* opaque extension_data<0..2^16-1> length */
138 		WPA_PUT_BE16(pos, 8);
139 		pos += 2;
140 		/* supported_signature_algorithms<2..2^16-2> length */
141 		WPA_PUT_BE16(pos, 6);
142 		pos += 2;
143 		/* supported_signature_algorithms */
144 		*pos++ = TLS_HASH_ALG_SHA512;
145 		*pos++ = TLS_SIGN_ALG_RSA;
146 		*pos++ = TLS_HASH_ALG_SHA384;
147 		*pos++ = TLS_SIGN_ALG_RSA;
148 		*pos++ = TLS_HASH_ALG_SHA256;
149 		*pos++ = TLS_SIGN_ALG_RSA;
150 	}
151 #endif /* CONFIG_TLSV12 */
152 
153 	if (conn->client_hello_ext) {
154 		os_memcpy(pos, conn->client_hello_ext,
155 			  conn->client_hello_ext_len);
156 		pos += conn->client_hello_ext_len;
157 	}
158 
159 	if (conn->flags & TLS_CONN_REQUEST_OCSP) {
160 		wpa_printf(MSG_DEBUG,
161 			   "TLSv1: Add status_request extension for OCSP stapling");
162 		/* ExtensionsType extension_type = status_request(5) */
163 		WPA_PUT_BE16(pos, TLS_EXT_STATUS_REQUEST);
164 		pos += 2;
165 		/* opaque extension_data<0..2^16-1> length */
166 		WPA_PUT_BE16(pos, 5);
167 		pos += 2;
168 
169 		/*
170 		 * RFC 6066, 8:
171 		 * struct {
172 		 *     CertificateStatusType status_type;
173 		 *     select (status_type) {
174 		 *         case ocsp: OCSPStatusRequest;
175 		 *     } request;
176 		 * } CertificateStatusRequest;
177 		 *
178 		 * enum { ocsp(1), (255) } CertificateStatusType;
179 		 */
180 		*pos++ = 1; /* status_type = ocsp(1) */
181 
182 		/*
183 		 * struct {
184 		 *     ResponderID responder_id_list<0..2^16-1>;
185 		 *     Extensions  request_extensions;
186 		 * } OCSPStatusRequest;
187 		 *
188 		 * opaque ResponderID<1..2^16-1>;
189 		 * opaque Extensions<0..2^16-1>;
190 		 */
191 		WPA_PUT_BE16(pos, 0); /* responder_id_list(empty) */
192 		pos += 2;
193 		WPA_PUT_BE16(pos, 0); /* request_extensions(empty) */
194 		pos += 2;
195 
196 		wpa_printf(MSG_DEBUG,
197 			   "TLSv1: Add status_request_v2 extension for OCSP stapling");
198 		/* ExtensionsType extension_type = status_request_v2(17) */
199 		WPA_PUT_BE16(pos, TLS_EXT_STATUS_REQUEST_V2);
200 		pos += 2;
201 		/* opaque extension_data<0..2^16-1> length */
202 		WPA_PUT_BE16(pos, 7);
203 		pos += 2;
204 
205 		/*
206 		 * RFC 6961, 2.2:
207 		 * struct {
208 		 *     CertificateStatusType status_type;
209 		 *     uint16 request_length;
210 		 *     select (status_type) {
211 		 *         case ocsp: OCSPStatusRequest;
212 		 *         case ocsp_multi: OCSPStatusRequest;
213 		 *     } request;
214 		 * } CertificateStatusRequestItemV2;
215 		 *
216 		 * enum { ocsp(1), ocsp_multi(2), (255) } CertificateStatusType;
217 		 *
218 		 * struct {
219 		 * CertificateStatusRequestItemV2
220 		 *     certificate_status_req_list<1..2^16-1>;
221 		 * } CertificateStatusRequestListV2;
222 		 */
223 
224 		/* certificate_status_req_list<1..2^16-1> */
225 		WPA_PUT_BE16(pos, 5);
226 		pos += 2;
227 
228 		/* CertificateStatusRequestItemV2 */
229 		*pos++ = 2; /* status_type = ocsp_multi(2) */
230 		/* OCSPStatusRequest as shown above for v1 */
231 		WPA_PUT_BE16(pos, 0); /* responder_id_list(empty) */
232 		pos += 2;
233 		WPA_PUT_BE16(pos, 0); /* request_extensions(empty) */
234 		pos += 2;
235 	}
236 
237 	if (pos == ext_start + 2)
238 		pos -= 2; /* no extensions */
239 	else
240 		WPA_PUT_BE16(ext_start, pos - ext_start - 2);
241 
242 	WPA_PUT_BE24(hs_length, pos - hs_length - 3);
243 	tls_verify_hash_add(&conn->verify, hs_start, pos - hs_start);
244 
245 	if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_HANDSHAKE,
246 			      rhdr, end - rhdr, hs_start, pos - hs_start,
247 			      out_len) < 0) {
248 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to create TLS record");
249 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
250 			  TLS_ALERT_INTERNAL_ERROR);
251 		os_free(hello);
252 		return NULL;
253 	}
254 
255 	conn->state = SERVER_HELLO;
256 
257 	return hello;
258 }
259 
260 
tls_write_client_certificate(struct tlsv1_client * conn,u8 ** msgpos,u8 * end)261 static int tls_write_client_certificate(struct tlsv1_client *conn,
262 					u8 **msgpos, u8 *end)
263 {
264 	u8 *pos, *rhdr, *hs_start, *hs_length, *cert_start;
265 	size_t rlen;
266 	struct x509_certificate *cert;
267 
268 	pos = *msgpos;
269 	if (TLS_RECORD_HEADER_LEN + 1 + 3 + 3 > end - pos) {
270 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
271 			  TLS_ALERT_INTERNAL_ERROR);
272 		return -1;
273 	}
274 
275 	wpa_printf(MSG_DEBUG, "TLSv1: Send Certificate");
276 	rhdr = pos;
277 	pos += TLS_RECORD_HEADER_LEN;
278 
279 	/* opaque fragment[TLSPlaintext.length] */
280 
281 	/* Handshake */
282 	hs_start = pos;
283 	/* HandshakeType msg_type */
284 	*pos++ = TLS_HANDSHAKE_TYPE_CERTIFICATE;
285 	/* uint24 length (to be filled) */
286 	hs_length = pos;
287 	pos += 3;
288 	/* body - Certificate */
289 	/* uint24 length (to be filled) */
290 	cert_start = pos;
291 	pos += 3;
292 	cert = conn->cred ? conn->cred->cert : NULL;
293 	while (cert) {
294 		if (3 + cert->cert_len > (size_t) (end - pos)) {
295 			wpa_printf(MSG_DEBUG, "TLSv1: Not enough buffer space "
296 				   "for Certificate (cert_len=%lu left=%lu)",
297 				   (unsigned long) cert->cert_len,
298 				   (unsigned long) (end - pos));
299 			tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
300 				  TLS_ALERT_INTERNAL_ERROR);
301 			return -1;
302 		}
303 		WPA_PUT_BE24(pos, cert->cert_len);
304 		pos += 3;
305 		os_memcpy(pos, cert->cert_start, cert->cert_len);
306 		pos += cert->cert_len;
307 
308 		if (x509_certificate_self_signed(cert))
309 			break;
310 		cert = x509_certificate_get_subject(conn->cred->trusted_certs,
311 						    &cert->issuer);
312 	}
313 	if (conn->cred == NULL || cert == conn->cred->cert || cert == NULL) {
314 		/*
315 		 * Client was not configured with all the needed certificates
316 		 * to form a full certificate chain. The server may fail to
317 		 * validate the chain unless it is configured with all the
318 		 * missing CA certificates.
319 		 */
320 		wpa_printf(MSG_DEBUG, "TLSv1: Full client certificate chain "
321 			   "not configured - validation may fail");
322 	}
323 	WPA_PUT_BE24(cert_start, pos - cert_start - 3);
324 
325 	WPA_PUT_BE24(hs_length, pos - hs_length - 3);
326 
327 	if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_HANDSHAKE,
328 			      rhdr, end - rhdr, hs_start, pos - hs_start,
329 			      &rlen) < 0) {
330 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to generate a record");
331 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
332 			  TLS_ALERT_INTERNAL_ERROR);
333 		return -1;
334 	}
335 	pos = rhdr + rlen;
336 
337 	tls_verify_hash_add(&conn->verify, hs_start, pos - hs_start);
338 
339 	*msgpos = pos;
340 
341 	return 0;
342 }
343 
344 
tlsv1_key_x_dh(struct tlsv1_client * conn,u8 ** pos,u8 * end)345 static int tlsv1_key_x_dh(struct tlsv1_client *conn, u8 **pos, u8 *end)
346 {
347 	/* ClientDiffieHellmanPublic */
348 	u8 *csecret, *csecret_start, *dh_yc, *shared;
349 	size_t csecret_len, dh_yc_len, shared_len;
350 
351 	csecret_len = conn->dh_p_len;
352 	csecret = os_malloc(csecret_len);
353 	if (csecret == NULL) {
354 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to allocate "
355 			   "memory for Yc (Diffie-Hellman)");
356 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
357 			  TLS_ALERT_INTERNAL_ERROR);
358 		return -1;
359 	}
360 	if (random_get_bytes(csecret, csecret_len)) {
361 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to get random "
362 			   "data for Diffie-Hellman");
363 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
364 			  TLS_ALERT_INTERNAL_ERROR);
365 		os_free(csecret);
366 		return -1;
367 	}
368 
369 	if (os_memcmp(csecret, conn->dh_p, csecret_len) > 0)
370 		csecret[0] = 0; /* make sure Yc < p */
371 
372 	csecret_start = csecret;
373 	while (csecret_len > 1 && *csecret_start == 0) {
374 		csecret_start++;
375 		csecret_len--;
376 	}
377 	wpa_hexdump_key(MSG_DEBUG, "TLSv1: DH client's secret value",
378 			csecret_start, csecret_len);
379 
380 	/* Yc = g^csecret mod p */
381 	dh_yc_len = conn->dh_p_len;
382 	dh_yc = os_malloc(dh_yc_len);
383 	if (dh_yc == NULL) {
384 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to allocate "
385 			   "memory for Diffie-Hellman");
386 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
387 			  TLS_ALERT_INTERNAL_ERROR);
388 		os_free(csecret);
389 		return -1;
390 	}
391 	if (crypto_mod_exp(conn->dh_g, conn->dh_g_len,
392 			   csecret_start, csecret_len,
393 			   conn->dh_p, conn->dh_p_len,
394 			   dh_yc, &dh_yc_len)) {
395 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
396 			  TLS_ALERT_INTERNAL_ERROR);
397 		os_free(csecret);
398 		os_free(dh_yc);
399 		return -1;
400 	}
401 
402 	wpa_hexdump(MSG_DEBUG, "TLSv1: DH Yc (client's public value)",
403 		    dh_yc, dh_yc_len);
404 
405 	if (end - *pos < 2) {
406 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
407 			  TLS_ALERT_INTERNAL_ERROR);
408 		os_free(csecret);
409 		os_free(dh_yc);
410 		return -1;
411 	}
412 	WPA_PUT_BE16(*pos, dh_yc_len);
413 	*pos += 2;
414 	if (dh_yc_len > (size_t) (end - *pos)) {
415 		wpa_printf(MSG_DEBUG, "TLSv1: Not enough room in the "
416 			   "message buffer for Yc");
417 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
418 			  TLS_ALERT_INTERNAL_ERROR);
419 		os_free(csecret);
420 		os_free(dh_yc);
421 		return -1;
422 	}
423 	os_memcpy(*pos, dh_yc, dh_yc_len);
424 	*pos += dh_yc_len;
425 	os_free(dh_yc);
426 
427 	shared_len = conn->dh_p_len;
428 	shared = os_malloc(shared_len);
429 	if (shared == NULL) {
430 		wpa_printf(MSG_DEBUG, "TLSv1: Could not allocate memory for "
431 			   "DH");
432 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
433 			  TLS_ALERT_INTERNAL_ERROR);
434 		os_free(csecret);
435 		return -1;
436 	}
437 
438 	/* shared = Ys^csecret mod p */
439 	if (crypto_mod_exp(conn->dh_ys, conn->dh_ys_len,
440 			   csecret_start, csecret_len,
441 			   conn->dh_p, conn->dh_p_len,
442 			   shared, &shared_len)) {
443 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
444 			  TLS_ALERT_INTERNAL_ERROR);
445 		os_free(csecret);
446 		os_free(shared);
447 		return -1;
448 	}
449 	wpa_hexdump_key(MSG_DEBUG, "TLSv1: Shared secret from DH key exchange",
450 			shared, shared_len);
451 
452 	os_memset(csecret_start, 0, csecret_len);
453 	os_free(csecret);
454 	if (tls_derive_keys(conn, shared, shared_len)) {
455 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to derive keys");
456 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
457 			  TLS_ALERT_INTERNAL_ERROR);
458 		os_free(shared);
459 		return -1;
460 	}
461 	os_memset(shared, 0, shared_len);
462 	os_free(shared);
463 	tlsv1_client_free_dh(conn);
464 	return 0;
465 }
466 
467 
tlsv1_key_x_rsa(struct tlsv1_client * conn,u8 ** pos,u8 * end)468 static int tlsv1_key_x_rsa(struct tlsv1_client *conn, u8 **pos, u8 *end)
469 {
470 	u8 pre_master_secret[TLS_PRE_MASTER_SECRET_LEN];
471 	size_t clen;
472 	int res;
473 
474 	if (tls_derive_pre_master_secret(pre_master_secret) < 0 ||
475 	    tls_derive_keys(conn, pre_master_secret,
476 			    TLS_PRE_MASTER_SECRET_LEN)) {
477 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to derive keys");
478 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
479 			  TLS_ALERT_INTERNAL_ERROR);
480 		return -1;
481 	}
482 
483 	/* EncryptedPreMasterSecret */
484 	if (conn->server_rsa_key == NULL) {
485 		wpa_printf(MSG_DEBUG, "TLSv1: No server RSA key to "
486 			   "use for encrypting pre-master secret");
487 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
488 			  TLS_ALERT_INTERNAL_ERROR);
489 		return -1;
490 	}
491 
492 	/* RSA encrypted value is encoded with PKCS #1 v1.5 block type 2. */
493 	*pos += 2;
494 	clen = end - *pos;
495 	res = crypto_public_key_encrypt_pkcs1_v15(
496 		conn->server_rsa_key,
497 		pre_master_secret, TLS_PRE_MASTER_SECRET_LEN,
498 		*pos, &clen);
499 	os_memset(pre_master_secret, 0, TLS_PRE_MASTER_SECRET_LEN);
500 	if (res < 0) {
501 		wpa_printf(MSG_DEBUG, "TLSv1: RSA encryption failed");
502 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
503 			  TLS_ALERT_INTERNAL_ERROR);
504 		return -1;
505 	}
506 	WPA_PUT_BE16(*pos - 2, clen);
507 	wpa_hexdump(MSG_MSGDUMP, "TLSv1: Encrypted pre_master_secret",
508 		    *pos, clen);
509 	*pos += clen;
510 
511 	return 0;
512 }
513 
514 
tls_write_client_key_exchange(struct tlsv1_client * conn,u8 ** msgpos,u8 * end)515 static int tls_write_client_key_exchange(struct tlsv1_client *conn,
516 					 u8 **msgpos, u8 *end)
517 {
518 	u8 *pos, *rhdr, *hs_start, *hs_length;
519 	size_t rlen;
520 	tls_key_exchange keyx;
521 	const struct tls_cipher_suite *suite;
522 
523 	suite = tls_get_cipher_suite(conn->rl.cipher_suite);
524 	if (suite == NULL)
525 		keyx = TLS_KEY_X_NULL;
526 	else
527 		keyx = suite->key_exchange;
528 
529 	pos = *msgpos;
530 
531 	wpa_printf(MSG_DEBUG, "TLSv1: Send ClientKeyExchange");
532 
533 	rhdr = pos;
534 	pos += TLS_RECORD_HEADER_LEN;
535 
536 	/* opaque fragment[TLSPlaintext.length] */
537 
538 	/* Handshake */
539 	hs_start = pos;
540 	/* HandshakeType msg_type */
541 	*pos++ = TLS_HANDSHAKE_TYPE_CLIENT_KEY_EXCHANGE;
542 	/* uint24 length (to be filled) */
543 	hs_length = pos;
544 	pos += 3;
545 	/* body - ClientKeyExchange */
546 	if (keyx == TLS_KEY_X_DH_anon || keyx == TLS_KEY_X_DHE_RSA) {
547 		if (tlsv1_key_x_dh(conn, &pos, end) < 0)
548 			return -1;
549 	} else {
550 		if (tlsv1_key_x_rsa(conn, &pos, end) < 0)
551 			return -1;
552 	}
553 
554 	WPA_PUT_BE24(hs_length, pos - hs_length - 3);
555 
556 	if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_HANDSHAKE,
557 			      rhdr, end - rhdr, hs_start, pos - hs_start,
558 			      &rlen) < 0) {
559 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to create a record");
560 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
561 			  TLS_ALERT_INTERNAL_ERROR);
562 		return -1;
563 	}
564 	pos = rhdr + rlen;
565 	tls_verify_hash_add(&conn->verify, hs_start, pos - hs_start);
566 
567 	*msgpos = pos;
568 
569 	return 0;
570 }
571 
572 
tls_write_client_certificate_verify(struct tlsv1_client * conn,u8 ** msgpos,u8 * end)573 static int tls_write_client_certificate_verify(struct tlsv1_client *conn,
574 					       u8 **msgpos, u8 *end)
575 {
576 	u8 *pos, *rhdr, *hs_start, *hs_length, *signed_start;
577 	size_t rlen, hlen, clen;
578 	u8 hash[100], *hpos;
579 
580 	pos = *msgpos;
581 
582 	wpa_printf(MSG_DEBUG, "TLSv1: Send CertificateVerify");
583 	rhdr = pos;
584 	pos += TLS_RECORD_HEADER_LEN;
585 
586 	/* Handshake */
587 	hs_start = pos;
588 	/* HandshakeType msg_type */
589 	*pos++ = TLS_HANDSHAKE_TYPE_CERTIFICATE_VERIFY;
590 	/* uint24 length (to be filled) */
591 	hs_length = pos;
592 	pos += 3;
593 
594 	/*
595 	 * RFC 2246: 7.4.3 and 7.4.8:
596 	 * Signature signature
597 	 *
598 	 * RSA:
599 	 * digitally-signed struct {
600 	 *     opaque md5_hash[16];
601 	 *     opaque sha_hash[20];
602 	 * };
603 	 *
604 	 * DSA:
605 	 * digitally-signed struct {
606 	 *     opaque sha_hash[20];
607 	 * };
608 	 *
609 	 * The hash values are calculated over all handshake messages sent or
610 	 * received starting at ClientHello up to, but not including, this
611 	 * CertificateVerify message, including the type and length fields of
612 	 * the handshake messages.
613 	 */
614 
615 	hpos = hash;
616 
617 #ifdef CONFIG_TLSV12
618 	if (conn->rl.tls_version == TLS_VERSION_1_2) {
619 		hlen = SHA256_MAC_LEN;
620 		if (conn->verify.sha256_cert == NULL ||
621 		    crypto_hash_finish(conn->verify.sha256_cert, hpos, &hlen) <
622 		    0) {
623 			conn->verify.sha256_cert = NULL;
624 			tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
625 				  TLS_ALERT_INTERNAL_ERROR);
626 			return -1;
627 		}
628 		conn->verify.sha256_cert = NULL;
629 
630 		/*
631 		 * RFC 3447, A.2.4 RSASSA-PKCS1-v1_5
632 		 *
633 		 * DigestInfo ::= SEQUENCE {
634 		 *   digestAlgorithm DigestAlgorithm,
635 		 *   digest OCTET STRING
636 		 * }
637 		 *
638 		 * SHA-256 OID: sha256WithRSAEncryption ::= {pkcs-1 11}
639 		 *
640 		 * DER encoded DigestInfo for SHA256 per RFC 3447:
641 		 * 30 31 30 0d 06 09 60 86 48 01 65 03 04 02 01 05 00 04 20 ||
642 		 * H
643 		 */
644 		os_memmove(hash + 19, hash, hlen);
645 		hlen += 19;
646 		os_memcpy(hash, "\x30\x31\x30\x0d\x06\x09\x60\x86\x48\x01\x65"
647 			  "\x03\x04\x02\x01\x05\x00\x04\x20", 19);
648 	} else {
649 #endif /* CONFIG_TLSV12 */
650 
651 	hlen = MD5_MAC_LEN;
652 	if (conn->verify.md5_cert == NULL ||
653 	    crypto_hash_finish(conn->verify.md5_cert, hpos, &hlen) < 0) {
654 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
655 			  TLS_ALERT_INTERNAL_ERROR);
656 		conn->verify.md5_cert = NULL;
657 		crypto_hash_finish(conn->verify.sha1_cert, NULL, NULL);
658 		conn->verify.sha1_cert = NULL;
659 		return -1;
660 	}
661 	hpos += MD5_MAC_LEN;
662 
663 	conn->verify.md5_cert = NULL;
664 	hlen = SHA1_MAC_LEN;
665 	if (conn->verify.sha1_cert == NULL ||
666 	    crypto_hash_finish(conn->verify.sha1_cert, hpos, &hlen) < 0) {
667 		conn->verify.sha1_cert = NULL;
668 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
669 			  TLS_ALERT_INTERNAL_ERROR);
670 		return -1;
671 	}
672 	conn->verify.sha1_cert = NULL;
673 
674 	hlen += MD5_MAC_LEN;
675 
676 #ifdef CONFIG_TLSV12
677 	}
678 #endif /* CONFIG_TLSV12 */
679 
680 	wpa_hexdump(MSG_MSGDUMP, "TLSv1: CertificateVerify hash", hash, hlen);
681 
682 #ifdef CONFIG_TLSV12
683 	if (conn->rl.tls_version >= TLS_VERSION_1_2) {
684 		/*
685 		 * RFC 5246, 4.7:
686 		 * TLS v1.2 adds explicit indication of the used signature and
687 		 * hash algorithms.
688 		 *
689 		 * struct {
690 		 *   HashAlgorithm hash;
691 		 *   SignatureAlgorithm signature;
692 		 * } SignatureAndHashAlgorithm;
693 		 */
694 		*pos++ = TLS_HASH_ALG_SHA256;
695 		*pos++ = TLS_SIGN_ALG_RSA;
696 	}
697 #endif /* CONFIG_TLSV12 */
698 
699 	/*
700 	 * RFC 2246, 4.7:
701 	 * In digital signing, one-way hash functions are used as input for a
702 	 * signing algorithm. A digitally-signed element is encoded as an
703 	 * opaque vector <0..2^16-1>, where the length is specified by the
704 	 * signing algorithm and key.
705 	 *
706 	 * In RSA signing, a 36-byte structure of two hashes (one SHA and one
707 	 * MD5) is signed (encrypted with the private key). It is encoded with
708 	 * PKCS #1 block type 0 or type 1 as described in [PKCS1].
709 	 */
710 	signed_start = pos; /* length to be filled */
711 	pos += 2;
712 	clen = end - pos;
713 	if (conn->cred == NULL ||
714 	    crypto_private_key_sign_pkcs1(conn->cred->key, hash, hlen,
715 					  pos, &clen) < 0) {
716 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to sign hash (PKCS #1)");
717 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
718 			  TLS_ALERT_INTERNAL_ERROR);
719 		return -1;
720 	}
721 	WPA_PUT_BE16(signed_start, clen);
722 
723 	pos += clen;
724 
725 	WPA_PUT_BE24(hs_length, pos - hs_length - 3);
726 
727 	if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_HANDSHAKE,
728 			      rhdr, end - rhdr, hs_start, pos - hs_start,
729 			      &rlen) < 0) {
730 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to generate a record");
731 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
732 			  TLS_ALERT_INTERNAL_ERROR);
733 		return -1;
734 	}
735 	pos = rhdr + rlen;
736 
737 	tls_verify_hash_add(&conn->verify, hs_start, pos - hs_start);
738 
739 	*msgpos = pos;
740 
741 	return 0;
742 }
743 
744 
tls_write_client_change_cipher_spec(struct tlsv1_client * conn,u8 ** msgpos,u8 * end)745 static int tls_write_client_change_cipher_spec(struct tlsv1_client *conn,
746 					       u8 **msgpos, u8 *end)
747 {
748 	size_t rlen;
749 	u8 payload[1];
750 
751 	wpa_printf(MSG_DEBUG, "TLSv1: Send ChangeCipherSpec");
752 
753 	payload[0] = TLS_CHANGE_CIPHER_SPEC;
754 
755 	if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_CHANGE_CIPHER_SPEC,
756 			      *msgpos, end - *msgpos, payload, sizeof(payload),
757 			      &rlen) < 0) {
758 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to create a record");
759 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
760 			  TLS_ALERT_INTERNAL_ERROR);
761 		return -1;
762 	}
763 
764 	if (tlsv1_record_change_write_cipher(&conn->rl) < 0) {
765 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to set write cipher for "
766 			   "record layer");
767 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
768 			  TLS_ALERT_INTERNAL_ERROR);
769 		return -1;
770 	}
771 
772 	*msgpos += rlen;
773 
774 	return 0;
775 }
776 
777 
tls_write_client_finished(struct tlsv1_client * conn,u8 ** msgpos,u8 * end)778 static int tls_write_client_finished(struct tlsv1_client *conn,
779 				     u8 **msgpos, u8 *end)
780 {
781 	u8 *pos, *hs_start;
782 	size_t rlen, hlen;
783 	u8 verify_data[1 + 3 + TLS_VERIFY_DATA_LEN];
784 	u8 hash[MD5_MAC_LEN + SHA1_MAC_LEN];
785 
786 	wpa_printf(MSG_DEBUG, "TLSv1: Send Finished");
787 
788 	/* Encrypted Handshake Message: Finished */
789 
790 #ifdef CONFIG_TLSV12
791 	if (conn->rl.tls_version >= TLS_VERSION_1_2) {
792 		hlen = SHA256_MAC_LEN;
793 		if (conn->verify.sha256_client == NULL ||
794 		    crypto_hash_finish(conn->verify.sha256_client, hash, &hlen)
795 		    < 0) {
796 			tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
797 				  TLS_ALERT_INTERNAL_ERROR);
798 			conn->verify.sha256_client = NULL;
799 			return -1;
800 		}
801 		conn->verify.sha256_client = NULL;
802 	} else {
803 #endif /* CONFIG_TLSV12 */
804 
805 	hlen = MD5_MAC_LEN;
806 	if (conn->verify.md5_client == NULL ||
807 	    crypto_hash_finish(conn->verify.md5_client, hash, &hlen) < 0) {
808 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
809 			  TLS_ALERT_INTERNAL_ERROR);
810 		conn->verify.md5_client = NULL;
811 		crypto_hash_finish(conn->verify.sha1_client, NULL, NULL);
812 		conn->verify.sha1_client = NULL;
813 		return -1;
814 	}
815 	conn->verify.md5_client = NULL;
816 	hlen = SHA1_MAC_LEN;
817 	if (conn->verify.sha1_client == NULL ||
818 	    crypto_hash_finish(conn->verify.sha1_client, hash + MD5_MAC_LEN,
819 			       &hlen) < 0) {
820 		conn->verify.sha1_client = NULL;
821 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
822 			  TLS_ALERT_INTERNAL_ERROR);
823 		return -1;
824 	}
825 	conn->verify.sha1_client = NULL;
826 	hlen = MD5_MAC_LEN + SHA1_MAC_LEN;
827 
828 #ifdef CONFIG_TLSV12
829 	}
830 #endif /* CONFIG_TLSV12 */
831 
832 	if (tls_prf(conn->rl.tls_version,
833 		    conn->master_secret, TLS_MASTER_SECRET_LEN,
834 		    "client finished", hash, hlen,
835 		    verify_data + 1 + 3, TLS_VERIFY_DATA_LEN)) {
836 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to generate verify_data");
837 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
838 			  TLS_ALERT_INTERNAL_ERROR);
839 		return -1;
840 	}
841 	wpa_hexdump_key(MSG_DEBUG, "TLSv1: verify_data (client)",
842 			verify_data + 1 + 3, TLS_VERIFY_DATA_LEN);
843 
844 	/* Handshake */
845 	pos = hs_start = verify_data;
846 	/* HandshakeType msg_type */
847 	*pos++ = TLS_HANDSHAKE_TYPE_FINISHED;
848 	/* uint24 length */
849 	WPA_PUT_BE24(pos, TLS_VERIFY_DATA_LEN);
850 	pos += 3;
851 	pos += TLS_VERIFY_DATA_LEN; /* verify_data already in place */
852 	tls_verify_hash_add(&conn->verify, hs_start, pos - hs_start);
853 
854 	if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_HANDSHAKE,
855 			      *msgpos, end - *msgpos, hs_start, pos - hs_start,
856 			      &rlen) < 0) {
857 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to create a record");
858 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
859 			  TLS_ALERT_INTERNAL_ERROR);
860 		return -1;
861 	}
862 
863 	*msgpos += rlen;
864 
865 	return 0;
866 }
867 
868 
tls_send_client_key_exchange(struct tlsv1_client * conn,size_t * out_len)869 static u8 * tls_send_client_key_exchange(struct tlsv1_client *conn,
870 					 size_t *out_len)
871 {
872 	u8 *msg, *end, *pos;
873 	size_t msglen;
874 
875 	*out_len = 0;
876 
877 	msglen = 2000;
878 	if (conn->certificate_requested)
879 		msglen += tls_client_cert_chain_der_len(conn);
880 
881 	msg = os_malloc(msglen);
882 	if (msg == NULL)
883 		return NULL;
884 
885 	pos = msg;
886 	end = msg + msglen;
887 
888 	if (conn->certificate_requested) {
889 		if (tls_write_client_certificate(conn, &pos, end) < 0) {
890 			os_free(msg);
891 			return NULL;
892 		}
893 	}
894 
895 	if (tls_write_client_key_exchange(conn, &pos, end) < 0 ||
896 	    (conn->certificate_requested && conn->cred && conn->cred->key &&
897 	     tls_write_client_certificate_verify(conn, &pos, end) < 0) ||
898 	    tls_write_client_change_cipher_spec(conn, &pos, end) < 0 ||
899 	    tls_write_client_finished(conn, &pos, end) < 0) {
900 		os_free(msg);
901 		return NULL;
902 	}
903 
904 	*out_len = pos - msg;
905 
906 	conn->state = SERVER_CHANGE_CIPHER_SPEC;
907 
908 	return msg;
909 }
910 
911 
tls_send_change_cipher_spec(struct tlsv1_client * conn,size_t * out_len)912 static u8 * tls_send_change_cipher_spec(struct tlsv1_client *conn,
913 					size_t *out_len)
914 {
915 	u8 *msg, *end, *pos;
916 
917 	*out_len = 0;
918 
919 	msg = os_malloc(1000);
920 	if (msg == NULL)
921 		return NULL;
922 
923 	pos = msg;
924 	end = msg + 1000;
925 
926 	if (tls_write_client_change_cipher_spec(conn, &pos, end) < 0 ||
927 	    tls_write_client_finished(conn, &pos, end) < 0) {
928 		os_free(msg);
929 		return NULL;
930 	}
931 
932 	*out_len = pos - msg;
933 
934 	wpa_printf(MSG_DEBUG, "TLSv1: Session resumption completed "
935 		   "successfully");
936 	if (!conn->session_resumed && conn->use_session_ticket)
937 		conn->session_resumed = 1;
938 	conn->state = ESTABLISHED;
939 
940 	return msg;
941 }
942 
943 
tlsv1_client_handshake_write(struct tlsv1_client * conn,size_t * out_len,int no_appl_data)944 u8 * tlsv1_client_handshake_write(struct tlsv1_client *conn, size_t *out_len,
945 				  int no_appl_data)
946 {
947 	switch (conn->state) {
948 	case CLIENT_KEY_EXCHANGE:
949 		return tls_send_client_key_exchange(conn, out_len);
950 	case CHANGE_CIPHER_SPEC:
951 		return tls_send_change_cipher_spec(conn, out_len);
952 	case ACK_FINISHED:
953 		wpa_printf(MSG_DEBUG, "TLSv1: Handshake completed "
954 			   "successfully");
955 		conn->state = ESTABLISHED;
956 		*out_len = 0;
957 		if (no_appl_data) {
958 			/* Need to return something to get final TLS ACK. */
959 			return os_malloc(1);
960 		}
961 		return NULL;
962 	default:
963 		wpa_printf(MSG_DEBUG, "TLSv1: Unexpected state %d while "
964 			   "generating reply", conn->state);
965 		return NULL;
966 	}
967 }
968 
969 
tlsv1_client_send_alert(struct tlsv1_client * conn,u8 level,u8 description,size_t * out_len)970 u8 * tlsv1_client_send_alert(struct tlsv1_client *conn, u8 level,
971 			     u8 description, size_t *out_len)
972 {
973 	u8 *alert, *pos, *length;
974 
975 	wpa_printf(MSG_DEBUG, "TLSv1: Send Alert(%d:%d)", level, description);
976 	*out_len = 0;
977 
978 	alert = os_malloc(10);
979 	if (alert == NULL)
980 		return NULL;
981 
982 	pos = alert;
983 
984 	/* TLSPlaintext */
985 	/* ContentType type */
986 	*pos++ = TLS_CONTENT_TYPE_ALERT;
987 	/* ProtocolVersion version */
988 	WPA_PUT_BE16(pos, conn->rl.tls_version ? conn->rl.tls_version :
989 		     TLS_VERSION);
990 	pos += 2;
991 	/* uint16 length (to be filled) */
992 	length = pos;
993 	pos += 2;
994 	/* opaque fragment[TLSPlaintext.length] */
995 
996 	/* Alert */
997 	/* AlertLevel level */
998 	*pos++ = level;
999 	/* AlertDescription description */
1000 	*pos++ = description;
1001 
1002 	WPA_PUT_BE16(length, pos - length - 2);
1003 	*out_len = pos - alert;
1004 
1005 	return alert;
1006 }
1007