xref: /freebsd/contrib/wpa/src/tls/tlsv1_client_write.c (revision 7ef62cebc2f965b0f640263e179276928885e33d)
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 
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 
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_client_highest_ver(conn);
52 
53 	if (!tls_version) {
54 		wpa_printf(MSG_INFO, "TLSv1: No TLS version allowed");
55 		return NULL;
56 	}
57 
58 	wpa_printf(MSG_DEBUG, "TLSv1: Send ClientHello (ver %s)",
59 		   tls_version_str(tls_version));
60 	*out_len = 0;
61 
62 	os_get_time(&now);
63 #ifdef TEST_FUZZ
64 	now.sec = 0xfffefdfc;
65 #endif /* TEST_FUZZ */
66 	WPA_PUT_BE32(conn->client_random, now.sec);
67 	if (random_get_bytes(conn->client_random + 4, TLS_RANDOM_LEN - 4)) {
68 		wpa_printf(MSG_ERROR, "TLSv1: Could not generate "
69 			   "client_random");
70 		return NULL;
71 	}
72 	wpa_hexdump(MSG_MSGDUMP, "TLSv1: client_random",
73 		    conn->client_random, TLS_RANDOM_LEN);
74 
75 	len = 150 + conn->num_cipher_suites * 2 + conn->client_hello_ext_len;
76 	hello = os_malloc(len);
77 	if (hello == NULL)
78 		return NULL;
79 	end = hello + len;
80 
81 	rhdr = hello;
82 	pos = rhdr + TLS_RECORD_HEADER_LEN;
83 
84 	/* opaque fragment[TLSPlaintext.length] */
85 
86 	/* Handshake */
87 	hs_start = pos;
88 	/* HandshakeType msg_type */
89 	*pos++ = TLS_HANDSHAKE_TYPE_CLIENT_HELLO;
90 	/* uint24 length (to be filled) */
91 	hs_length = pos;
92 	pos += 3;
93 	/* body - ClientHello */
94 	/* ProtocolVersion client_version */
95 	WPA_PUT_BE16(pos, tls_version);
96 	pos += 2;
97 	/* Random random: uint32 gmt_unix_time, opaque random_bytes */
98 	os_memcpy(pos, conn->client_random, TLS_RANDOM_LEN);
99 	pos += TLS_RANDOM_LEN;
100 	/* SessionID session_id */
101 	*pos++ = conn->session_id_len;
102 	os_memcpy(pos, conn->session_id, conn->session_id_len);
103 	pos += conn->session_id_len;
104 	/* CipherSuite cipher_suites<2..2^16-1> */
105 	WPA_PUT_BE16(pos, 2 * conn->num_cipher_suites);
106 	pos += 2;
107 	for (i = 0; i < conn->num_cipher_suites; i++) {
108 		WPA_PUT_BE16(pos, conn->cipher_suites[i]);
109 		pos += 2;
110 	}
111 	/* CompressionMethod compression_methods<1..2^8-1> */
112 	*pos++ = 1;
113 	*pos++ = TLS_COMPRESSION_NULL;
114 
115 	/* Extension */
116 	ext_start = pos;
117 	pos += 2;
118 
119 #ifdef CONFIG_TLSV12
120 	if (conn->rl.tls_version >= TLS_VERSION_1_2) {
121 		/*
122 		 * Add signature_algorithms extension since we support only
123 		 * SHA256 (and not the default SHA1) with TLSv1.2.
124 		 */
125 		/* ExtensionsType extension_type = signature_algorithms(13) */
126 		WPA_PUT_BE16(pos, TLS_EXT_SIGNATURE_ALGORITHMS);
127 		pos += 2;
128 		/* opaque extension_data<0..2^16-1> length */
129 		WPA_PUT_BE16(pos, 8);
130 		pos += 2;
131 		/* supported_signature_algorithms<2..2^16-2> length */
132 		WPA_PUT_BE16(pos, 6);
133 		pos += 2;
134 		/* supported_signature_algorithms */
135 		*pos++ = TLS_HASH_ALG_SHA512;
136 		*pos++ = TLS_SIGN_ALG_RSA;
137 		*pos++ = TLS_HASH_ALG_SHA384;
138 		*pos++ = TLS_SIGN_ALG_RSA;
139 		*pos++ = TLS_HASH_ALG_SHA256;
140 		*pos++ = TLS_SIGN_ALG_RSA;
141 	}
142 #endif /* CONFIG_TLSV12 */
143 
144 	if (conn->client_hello_ext) {
145 		os_memcpy(pos, conn->client_hello_ext,
146 			  conn->client_hello_ext_len);
147 		pos += conn->client_hello_ext_len;
148 	}
149 
150 	if (conn->flags & TLS_CONN_REQUEST_OCSP) {
151 		wpa_printf(MSG_DEBUG,
152 			   "TLSv1: Add status_request extension for OCSP stapling");
153 		/* ExtensionsType extension_type = status_request(5) */
154 		WPA_PUT_BE16(pos, TLS_EXT_STATUS_REQUEST);
155 		pos += 2;
156 		/* opaque extension_data<0..2^16-1> length */
157 		WPA_PUT_BE16(pos, 5);
158 		pos += 2;
159 
160 		/*
161 		 * RFC 6066, 8:
162 		 * struct {
163 		 *     CertificateStatusType status_type;
164 		 *     select (status_type) {
165 		 *         case ocsp: OCSPStatusRequest;
166 		 *     } request;
167 		 * } CertificateStatusRequest;
168 		 *
169 		 * enum { ocsp(1), (255) } CertificateStatusType;
170 		 */
171 		*pos++ = 1; /* status_type = ocsp(1) */
172 
173 		/*
174 		 * struct {
175 		 *     ResponderID responder_id_list<0..2^16-1>;
176 		 *     Extensions  request_extensions;
177 		 * } OCSPStatusRequest;
178 		 *
179 		 * opaque ResponderID<1..2^16-1>;
180 		 * opaque Extensions<0..2^16-1>;
181 		 */
182 		WPA_PUT_BE16(pos, 0); /* responder_id_list(empty) */
183 		pos += 2;
184 		WPA_PUT_BE16(pos, 0); /* request_extensions(empty) */
185 		pos += 2;
186 
187 		wpa_printf(MSG_DEBUG,
188 			   "TLSv1: Add status_request_v2 extension for OCSP stapling");
189 		/* ExtensionsType extension_type = status_request_v2(17) */
190 		WPA_PUT_BE16(pos, TLS_EXT_STATUS_REQUEST_V2);
191 		pos += 2;
192 		/* opaque extension_data<0..2^16-1> length */
193 		WPA_PUT_BE16(pos, 7);
194 		pos += 2;
195 
196 		/*
197 		 * RFC 6961, 2.2:
198 		 * struct {
199 		 *     CertificateStatusType status_type;
200 		 *     uint16 request_length;
201 		 *     select (status_type) {
202 		 *         case ocsp: OCSPStatusRequest;
203 		 *         case ocsp_multi: OCSPStatusRequest;
204 		 *     } request;
205 		 * } CertificateStatusRequestItemV2;
206 		 *
207 		 * enum { ocsp(1), ocsp_multi(2), (255) } CertificateStatusType;
208 		 *
209 		 * struct {
210 		 * CertificateStatusRequestItemV2
211 		 *     certificate_status_req_list<1..2^16-1>;
212 		 * } CertificateStatusRequestListV2;
213 		 */
214 
215 		/* certificate_status_req_list<1..2^16-1> */
216 		WPA_PUT_BE16(pos, 5);
217 		pos += 2;
218 
219 		/* CertificateStatusRequestItemV2 */
220 		*pos++ = 2; /* status_type = ocsp_multi(2) */
221 		/* OCSPStatusRequest as shown above for v1 */
222 		WPA_PUT_BE16(pos, 0); /* responder_id_list(empty) */
223 		pos += 2;
224 		WPA_PUT_BE16(pos, 0); /* request_extensions(empty) */
225 		pos += 2;
226 	}
227 
228 	if (pos == ext_start + 2)
229 		pos -= 2; /* no extensions */
230 	else
231 		WPA_PUT_BE16(ext_start, pos - ext_start - 2);
232 
233 	WPA_PUT_BE24(hs_length, pos - hs_length - 3);
234 	tls_verify_hash_add(&conn->verify, hs_start, pos - hs_start);
235 
236 	if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_HANDSHAKE,
237 			      rhdr, end - rhdr, hs_start, pos - hs_start,
238 			      out_len) < 0) {
239 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to create TLS record");
240 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
241 			  TLS_ALERT_INTERNAL_ERROR);
242 		os_free(hello);
243 		return NULL;
244 	}
245 
246 	conn->state = SERVER_HELLO;
247 
248 	return hello;
249 }
250 
251 
252 static int tls_write_client_certificate(struct tlsv1_client *conn,
253 					u8 **msgpos, u8 *end)
254 {
255 	u8 *pos, *rhdr, *hs_start, *hs_length, *cert_start;
256 	size_t rlen;
257 	struct x509_certificate *cert;
258 
259 	pos = *msgpos;
260 	if (TLS_RECORD_HEADER_LEN + 1 + 3 + 3 > end - pos) {
261 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
262 			  TLS_ALERT_INTERNAL_ERROR);
263 		return -1;
264 	}
265 
266 	wpa_printf(MSG_DEBUG, "TLSv1: Send Certificate");
267 	rhdr = pos;
268 	pos += TLS_RECORD_HEADER_LEN;
269 
270 	/* opaque fragment[TLSPlaintext.length] */
271 
272 	/* Handshake */
273 	hs_start = pos;
274 	/* HandshakeType msg_type */
275 	*pos++ = TLS_HANDSHAKE_TYPE_CERTIFICATE;
276 	/* uint24 length (to be filled) */
277 	hs_length = pos;
278 	pos += 3;
279 	/* body - Certificate */
280 	/* uint24 length (to be filled) */
281 	cert_start = pos;
282 	pos += 3;
283 	cert = conn->cred ? conn->cred->cert : NULL;
284 	while (cert) {
285 		if (3 + cert->cert_len > (size_t) (end - pos)) {
286 			wpa_printf(MSG_DEBUG, "TLSv1: Not enough buffer space "
287 				   "for Certificate (cert_len=%lu left=%lu)",
288 				   (unsigned long) cert->cert_len,
289 				   (unsigned long) (end - pos));
290 			tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
291 				  TLS_ALERT_INTERNAL_ERROR);
292 			return -1;
293 		}
294 		WPA_PUT_BE24(pos, cert->cert_len);
295 		pos += 3;
296 		os_memcpy(pos, cert->cert_start, cert->cert_len);
297 		pos += cert->cert_len;
298 
299 		if (x509_certificate_self_signed(cert))
300 			break;
301 		cert = x509_certificate_get_subject(conn->cred->trusted_certs,
302 						    &cert->issuer);
303 	}
304 	if (conn->cred == NULL || cert == conn->cred->cert || cert == NULL) {
305 		/*
306 		 * Client was not configured with all the needed certificates
307 		 * to form a full certificate chain. The server may fail to
308 		 * validate the chain unless it is configured with all the
309 		 * missing CA certificates.
310 		 */
311 		wpa_printf(MSG_DEBUG, "TLSv1: Full client certificate chain "
312 			   "not configured - validation may fail");
313 	}
314 	WPA_PUT_BE24(cert_start, pos - cert_start - 3);
315 
316 	WPA_PUT_BE24(hs_length, pos - hs_length - 3);
317 
318 	if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_HANDSHAKE,
319 			      rhdr, end - rhdr, hs_start, pos - hs_start,
320 			      &rlen) < 0) {
321 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to generate a record");
322 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
323 			  TLS_ALERT_INTERNAL_ERROR);
324 		return -1;
325 	}
326 	pos = rhdr + rlen;
327 
328 	tls_verify_hash_add(&conn->verify, hs_start, pos - hs_start);
329 
330 	*msgpos = pos;
331 
332 	return 0;
333 }
334 
335 
336 static int tlsv1_key_x_dh(struct tlsv1_client *conn, u8 **pos, u8 *end)
337 {
338 	/* ClientDiffieHellmanPublic */
339 	u8 *csecret, *csecret_start, *dh_yc, *shared;
340 	size_t csecret_len, dh_yc_len, shared_len;
341 
342 	csecret_len = conn->dh_p_len;
343 	csecret = os_malloc(csecret_len);
344 	if (csecret == NULL) {
345 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to allocate "
346 			   "memory for Yc (Diffie-Hellman)");
347 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
348 			  TLS_ALERT_INTERNAL_ERROR);
349 		return -1;
350 	}
351 	if (random_get_bytes(csecret, csecret_len)) {
352 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to get random "
353 			   "data for Diffie-Hellman");
354 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
355 			  TLS_ALERT_INTERNAL_ERROR);
356 		os_free(csecret);
357 		return -1;
358 	}
359 
360 	if (os_memcmp(csecret, conn->dh_p, csecret_len) > 0)
361 		csecret[0] = 0; /* make sure Yc < p */
362 
363 	csecret_start = csecret;
364 	while (csecret_len > 1 && *csecret_start == 0) {
365 		csecret_start++;
366 		csecret_len--;
367 	}
368 	wpa_hexdump_key(MSG_DEBUG, "TLSv1: DH client's secret value",
369 			csecret_start, csecret_len);
370 
371 	/* Yc = g^csecret mod p */
372 	dh_yc_len = conn->dh_p_len;
373 	dh_yc = os_malloc(dh_yc_len);
374 	if (dh_yc == NULL) {
375 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to allocate "
376 			   "memory for Diffie-Hellman");
377 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
378 			  TLS_ALERT_INTERNAL_ERROR);
379 		os_free(csecret);
380 		return -1;
381 	}
382 	if (crypto_mod_exp(conn->dh_g, conn->dh_g_len,
383 			   csecret_start, csecret_len,
384 			   conn->dh_p, conn->dh_p_len,
385 			   dh_yc, &dh_yc_len)) {
386 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
387 			  TLS_ALERT_INTERNAL_ERROR);
388 		os_free(csecret);
389 		os_free(dh_yc);
390 		return -1;
391 	}
392 
393 	wpa_hexdump(MSG_DEBUG, "TLSv1: DH Yc (client's public value)",
394 		    dh_yc, dh_yc_len);
395 
396 	if (end - *pos < 2) {
397 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
398 			  TLS_ALERT_INTERNAL_ERROR);
399 		os_free(csecret);
400 		os_free(dh_yc);
401 		return -1;
402 	}
403 	WPA_PUT_BE16(*pos, dh_yc_len);
404 	*pos += 2;
405 	if (dh_yc_len > (size_t) (end - *pos)) {
406 		wpa_printf(MSG_DEBUG, "TLSv1: Not enough room in the "
407 			   "message buffer for Yc");
408 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
409 			  TLS_ALERT_INTERNAL_ERROR);
410 		os_free(csecret);
411 		os_free(dh_yc);
412 		return -1;
413 	}
414 	os_memcpy(*pos, dh_yc, dh_yc_len);
415 	*pos += dh_yc_len;
416 	os_free(dh_yc);
417 
418 	shared_len = conn->dh_p_len;
419 	shared = os_malloc(shared_len);
420 	if (shared == NULL) {
421 		wpa_printf(MSG_DEBUG, "TLSv1: Could not allocate memory for "
422 			   "DH");
423 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
424 			  TLS_ALERT_INTERNAL_ERROR);
425 		os_free(csecret);
426 		return -1;
427 	}
428 
429 	/* shared = Ys^csecret mod p */
430 	if (crypto_mod_exp(conn->dh_ys, conn->dh_ys_len,
431 			   csecret_start, csecret_len,
432 			   conn->dh_p, conn->dh_p_len,
433 			   shared, &shared_len)) {
434 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
435 			  TLS_ALERT_INTERNAL_ERROR);
436 		os_free(csecret);
437 		os_free(shared);
438 		return -1;
439 	}
440 	wpa_hexdump_key(MSG_DEBUG, "TLSv1: Shared secret from DH key exchange",
441 			shared, shared_len);
442 
443 	os_memset(csecret_start, 0, csecret_len);
444 	os_free(csecret);
445 	if (tls_derive_keys(conn, shared, shared_len)) {
446 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to derive keys");
447 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
448 			  TLS_ALERT_INTERNAL_ERROR);
449 		os_free(shared);
450 		return -1;
451 	}
452 	os_memset(shared, 0, shared_len);
453 	os_free(shared);
454 	tlsv1_client_free_dh(conn);
455 	return 0;
456 }
457 
458 
459 static int tlsv1_key_x_rsa(struct tlsv1_client *conn, u8 **pos, u8 *end)
460 {
461 	u8 pre_master_secret[TLS_PRE_MASTER_SECRET_LEN];
462 	size_t clen;
463 	int res;
464 
465 	if (tls_derive_pre_master_secret(conn, pre_master_secret) < 0 ||
466 	    tls_derive_keys(conn, pre_master_secret,
467 			    TLS_PRE_MASTER_SECRET_LEN)) {
468 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to derive keys");
469 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
470 			  TLS_ALERT_INTERNAL_ERROR);
471 		return -1;
472 	}
473 
474 	/* EncryptedPreMasterSecret */
475 	if (conn->server_rsa_key == NULL) {
476 		wpa_printf(MSG_DEBUG, "TLSv1: No server RSA key to "
477 			   "use for encrypting pre-master secret");
478 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
479 			  TLS_ALERT_INTERNAL_ERROR);
480 		return -1;
481 	}
482 
483 	/* RSA encrypted value is encoded with PKCS #1 v1.5 block type 2. */
484 	*pos += 2;
485 	clen = end - *pos;
486 	res = crypto_public_key_encrypt_pkcs1_v15(
487 		conn->server_rsa_key,
488 		pre_master_secret, TLS_PRE_MASTER_SECRET_LEN,
489 		*pos, &clen);
490 	os_memset(pre_master_secret, 0, TLS_PRE_MASTER_SECRET_LEN);
491 	if (res < 0) {
492 		wpa_printf(MSG_DEBUG, "TLSv1: RSA encryption failed");
493 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
494 			  TLS_ALERT_INTERNAL_ERROR);
495 		return -1;
496 	}
497 	WPA_PUT_BE16(*pos - 2, clen);
498 	wpa_hexdump(MSG_MSGDUMP, "TLSv1: Encrypted pre_master_secret",
499 		    *pos, clen);
500 	*pos += clen;
501 
502 	return 0;
503 }
504 
505 
506 static int tls_write_client_key_exchange(struct tlsv1_client *conn,
507 					 u8 **msgpos, u8 *end)
508 {
509 	u8 *pos, *rhdr, *hs_start, *hs_length;
510 	size_t rlen;
511 	tls_key_exchange keyx;
512 	const struct tls_cipher_suite *suite;
513 
514 	suite = tls_get_cipher_suite(conn->rl.cipher_suite);
515 	if (suite == NULL)
516 		keyx = TLS_KEY_X_NULL;
517 	else
518 		keyx = suite->key_exchange;
519 
520 	pos = *msgpos;
521 
522 	wpa_printf(MSG_DEBUG, "TLSv1: Send ClientKeyExchange");
523 
524 	rhdr = pos;
525 	pos += TLS_RECORD_HEADER_LEN;
526 
527 	/* opaque fragment[TLSPlaintext.length] */
528 
529 	/* Handshake */
530 	hs_start = pos;
531 	/* HandshakeType msg_type */
532 	*pos++ = TLS_HANDSHAKE_TYPE_CLIENT_KEY_EXCHANGE;
533 	/* uint24 length (to be filled) */
534 	hs_length = pos;
535 	pos += 3;
536 	/* body - ClientKeyExchange */
537 	if (keyx == TLS_KEY_X_DH_anon || keyx == TLS_KEY_X_DHE_RSA) {
538 		if (tlsv1_key_x_dh(conn, &pos, end) < 0)
539 			return -1;
540 	} else {
541 		if (tlsv1_key_x_rsa(conn, &pos, end) < 0)
542 			return -1;
543 	}
544 
545 	WPA_PUT_BE24(hs_length, pos - hs_length - 3);
546 
547 	if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_HANDSHAKE,
548 			      rhdr, end - rhdr, hs_start, pos - hs_start,
549 			      &rlen) < 0) {
550 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to create a record");
551 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
552 			  TLS_ALERT_INTERNAL_ERROR);
553 		return -1;
554 	}
555 	pos = rhdr + rlen;
556 	tls_verify_hash_add(&conn->verify, hs_start, pos - hs_start);
557 
558 	*msgpos = pos;
559 
560 	return 0;
561 }
562 
563 
564 static int tls_write_client_certificate_verify(struct tlsv1_client *conn,
565 					       u8 **msgpos, u8 *end)
566 {
567 	u8 *pos, *rhdr, *hs_start, *hs_length, *signed_start;
568 	size_t rlen, hlen, clen;
569 	u8 hash[100], *hpos;
570 
571 	pos = *msgpos;
572 
573 	wpa_printf(MSG_DEBUG, "TLSv1: Send CertificateVerify");
574 	rhdr = pos;
575 	pos += TLS_RECORD_HEADER_LEN;
576 
577 	/* Handshake */
578 	hs_start = pos;
579 	/* HandshakeType msg_type */
580 	*pos++ = TLS_HANDSHAKE_TYPE_CERTIFICATE_VERIFY;
581 	/* uint24 length (to be filled) */
582 	hs_length = pos;
583 	pos += 3;
584 
585 	/*
586 	 * RFC 2246: 7.4.3 and 7.4.8:
587 	 * Signature signature
588 	 *
589 	 * RSA:
590 	 * digitally-signed struct {
591 	 *     opaque md5_hash[16];
592 	 *     opaque sha_hash[20];
593 	 * };
594 	 *
595 	 * DSA:
596 	 * digitally-signed struct {
597 	 *     opaque sha_hash[20];
598 	 * };
599 	 *
600 	 * The hash values are calculated over all handshake messages sent or
601 	 * received starting at ClientHello up to, but not including, this
602 	 * CertificateVerify message, including the type and length fields of
603 	 * the handshake messages.
604 	 */
605 
606 	hpos = hash;
607 
608 #ifdef CONFIG_TLSV12
609 	if (conn->rl.tls_version == TLS_VERSION_1_2) {
610 		hlen = SHA256_MAC_LEN;
611 		if (conn->verify.sha256_cert == NULL ||
612 		    crypto_hash_finish(conn->verify.sha256_cert, hpos, &hlen) <
613 		    0) {
614 			conn->verify.sha256_cert = NULL;
615 			tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
616 				  TLS_ALERT_INTERNAL_ERROR);
617 			return -1;
618 		}
619 		conn->verify.sha256_cert = NULL;
620 
621 		/*
622 		 * RFC 3447, A.2.4 RSASSA-PKCS1-v1_5
623 		 *
624 		 * DigestInfo ::= SEQUENCE {
625 		 *   digestAlgorithm DigestAlgorithm,
626 		 *   digest OCTET STRING
627 		 * }
628 		 *
629 		 * SHA-256 OID: sha256WithRSAEncryption ::= {pkcs-1 11}
630 		 *
631 		 * DER encoded DigestInfo for SHA256 per RFC 3447:
632 		 * 30 31 30 0d 06 09 60 86 48 01 65 03 04 02 01 05 00 04 20 ||
633 		 * H
634 		 */
635 		os_memmove(hash + 19, hash, hlen);
636 		hlen += 19;
637 		os_memcpy(hash, "\x30\x31\x30\x0d\x06\x09\x60\x86\x48\x01\x65"
638 			  "\x03\x04\x02\x01\x05\x00\x04\x20", 19);
639 	} else {
640 #endif /* CONFIG_TLSV12 */
641 
642 	hlen = MD5_MAC_LEN;
643 	if (conn->verify.md5_cert == NULL ||
644 	    crypto_hash_finish(conn->verify.md5_cert, hpos, &hlen) < 0) {
645 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
646 			  TLS_ALERT_INTERNAL_ERROR);
647 		conn->verify.md5_cert = NULL;
648 		crypto_hash_finish(conn->verify.sha1_cert, NULL, NULL);
649 		conn->verify.sha1_cert = NULL;
650 		return -1;
651 	}
652 	hpos += MD5_MAC_LEN;
653 
654 	conn->verify.md5_cert = NULL;
655 	hlen = SHA1_MAC_LEN;
656 	if (conn->verify.sha1_cert == NULL ||
657 	    crypto_hash_finish(conn->verify.sha1_cert, hpos, &hlen) < 0) {
658 		conn->verify.sha1_cert = NULL;
659 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
660 			  TLS_ALERT_INTERNAL_ERROR);
661 		return -1;
662 	}
663 	conn->verify.sha1_cert = NULL;
664 
665 	hlen += MD5_MAC_LEN;
666 
667 #ifdef CONFIG_TLSV12
668 	}
669 #endif /* CONFIG_TLSV12 */
670 
671 	wpa_hexdump(MSG_MSGDUMP, "TLSv1: CertificateVerify hash", hash, hlen);
672 
673 #ifdef CONFIG_TLSV12
674 	if (conn->rl.tls_version >= TLS_VERSION_1_2) {
675 		/*
676 		 * RFC 5246, 4.7:
677 		 * TLS v1.2 adds explicit indication of the used signature and
678 		 * hash algorithms.
679 		 *
680 		 * struct {
681 		 *   HashAlgorithm hash;
682 		 *   SignatureAlgorithm signature;
683 		 * } SignatureAndHashAlgorithm;
684 		 */
685 		*pos++ = TLS_HASH_ALG_SHA256;
686 		*pos++ = TLS_SIGN_ALG_RSA;
687 	}
688 #endif /* CONFIG_TLSV12 */
689 
690 	/*
691 	 * RFC 2246, 4.7:
692 	 * In digital signing, one-way hash functions are used as input for a
693 	 * signing algorithm. A digitally-signed element is encoded as an
694 	 * opaque vector <0..2^16-1>, where the length is specified by the
695 	 * signing algorithm and key.
696 	 *
697 	 * In RSA signing, a 36-byte structure of two hashes (one SHA and one
698 	 * MD5) is signed (encrypted with the private key). It is encoded with
699 	 * PKCS #1 block type 0 or type 1 as described in [PKCS1].
700 	 */
701 	signed_start = pos; /* length to be filled */
702 	pos += 2;
703 	clen = end - pos;
704 	if (conn->cred == NULL ||
705 	    crypto_private_key_sign_pkcs1(conn->cred->key, hash, hlen,
706 					  pos, &clen) < 0) {
707 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to sign hash (PKCS #1)");
708 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
709 			  TLS_ALERT_INTERNAL_ERROR);
710 		return -1;
711 	}
712 	WPA_PUT_BE16(signed_start, clen);
713 
714 	pos += clen;
715 
716 	WPA_PUT_BE24(hs_length, pos - hs_length - 3);
717 
718 	if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_HANDSHAKE,
719 			      rhdr, end - rhdr, hs_start, pos - hs_start,
720 			      &rlen) < 0) {
721 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to generate a record");
722 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
723 			  TLS_ALERT_INTERNAL_ERROR);
724 		return -1;
725 	}
726 	pos = rhdr + rlen;
727 
728 	tls_verify_hash_add(&conn->verify, hs_start, pos - hs_start);
729 
730 	*msgpos = pos;
731 
732 	return 0;
733 }
734 
735 
736 static int tls_write_client_change_cipher_spec(struct tlsv1_client *conn,
737 					       u8 **msgpos, u8 *end)
738 {
739 	size_t rlen;
740 	u8 payload[1];
741 
742 	wpa_printf(MSG_DEBUG, "TLSv1: Send ChangeCipherSpec");
743 
744 	payload[0] = TLS_CHANGE_CIPHER_SPEC;
745 
746 	if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_CHANGE_CIPHER_SPEC,
747 			      *msgpos, end - *msgpos, payload, sizeof(payload),
748 			      &rlen) < 0) {
749 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to create a record");
750 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
751 			  TLS_ALERT_INTERNAL_ERROR);
752 		return -1;
753 	}
754 
755 	if (tlsv1_record_change_write_cipher(&conn->rl) < 0) {
756 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to set write cipher for "
757 			   "record layer");
758 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
759 			  TLS_ALERT_INTERNAL_ERROR);
760 		return -1;
761 	}
762 
763 	*msgpos += rlen;
764 
765 	return 0;
766 }
767 
768 
769 static int tls_write_client_finished(struct tlsv1_client *conn,
770 				     u8 **msgpos, u8 *end)
771 {
772 	u8 *pos, *hs_start;
773 	size_t rlen, hlen;
774 	u8 verify_data[1 + 3 + TLS_VERIFY_DATA_LEN];
775 	u8 hash[MD5_MAC_LEN + SHA1_MAC_LEN];
776 
777 	wpa_printf(MSG_DEBUG, "TLSv1: Send Finished");
778 
779 	/* Encrypted Handshake Message: Finished */
780 
781 #ifdef CONFIG_TLSV12
782 	if (conn->rl.tls_version >= TLS_VERSION_1_2) {
783 		hlen = SHA256_MAC_LEN;
784 		if (conn->verify.sha256_client == NULL ||
785 		    crypto_hash_finish(conn->verify.sha256_client, hash, &hlen)
786 		    < 0) {
787 			tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
788 				  TLS_ALERT_INTERNAL_ERROR);
789 			conn->verify.sha256_client = NULL;
790 			return -1;
791 		}
792 		conn->verify.sha256_client = NULL;
793 	} else {
794 #endif /* CONFIG_TLSV12 */
795 
796 	hlen = MD5_MAC_LEN;
797 	if (conn->verify.md5_client == NULL ||
798 	    crypto_hash_finish(conn->verify.md5_client, hash, &hlen) < 0) {
799 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
800 			  TLS_ALERT_INTERNAL_ERROR);
801 		conn->verify.md5_client = NULL;
802 		crypto_hash_finish(conn->verify.sha1_client, NULL, NULL);
803 		conn->verify.sha1_client = NULL;
804 		return -1;
805 	}
806 	conn->verify.md5_client = NULL;
807 	hlen = SHA1_MAC_LEN;
808 	if (conn->verify.sha1_client == NULL ||
809 	    crypto_hash_finish(conn->verify.sha1_client, hash + MD5_MAC_LEN,
810 			       &hlen) < 0) {
811 		conn->verify.sha1_client = NULL;
812 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
813 			  TLS_ALERT_INTERNAL_ERROR);
814 		return -1;
815 	}
816 	conn->verify.sha1_client = NULL;
817 	hlen = MD5_MAC_LEN + SHA1_MAC_LEN;
818 
819 #ifdef CONFIG_TLSV12
820 	}
821 #endif /* CONFIG_TLSV12 */
822 
823 	if (tls_prf(conn->rl.tls_version,
824 		    conn->master_secret, TLS_MASTER_SECRET_LEN,
825 		    "client finished", hash, hlen,
826 		    verify_data + 1 + 3, TLS_VERIFY_DATA_LEN)) {
827 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to generate verify_data");
828 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
829 			  TLS_ALERT_INTERNAL_ERROR);
830 		return -1;
831 	}
832 	wpa_hexdump_key(MSG_DEBUG, "TLSv1: verify_data (client)",
833 			verify_data + 1 + 3, TLS_VERIFY_DATA_LEN);
834 
835 	/* Handshake */
836 	pos = hs_start = verify_data;
837 	/* HandshakeType msg_type */
838 	*pos++ = TLS_HANDSHAKE_TYPE_FINISHED;
839 	/* uint24 length */
840 	WPA_PUT_BE24(pos, TLS_VERIFY_DATA_LEN);
841 	pos += 3;
842 	pos += TLS_VERIFY_DATA_LEN; /* verify_data already in place */
843 	tls_verify_hash_add(&conn->verify, hs_start, pos - hs_start);
844 
845 	if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_HANDSHAKE,
846 			      *msgpos, end - *msgpos, hs_start, pos - hs_start,
847 			      &rlen) < 0) {
848 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to create a record");
849 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
850 			  TLS_ALERT_INTERNAL_ERROR);
851 		return -1;
852 	}
853 
854 	*msgpos += rlen;
855 
856 	return 0;
857 }
858 
859 
860 static u8 * tls_send_client_key_exchange(struct tlsv1_client *conn,
861 					 size_t *out_len)
862 {
863 	u8 *msg, *end, *pos;
864 	size_t msglen;
865 
866 	*out_len = 0;
867 
868 	msglen = 2000;
869 	if (conn->certificate_requested)
870 		msglen += tls_client_cert_chain_der_len(conn);
871 
872 	msg = os_malloc(msglen);
873 	if (msg == NULL)
874 		return NULL;
875 
876 	pos = msg;
877 	end = msg + msglen;
878 
879 	if (conn->certificate_requested) {
880 		if (tls_write_client_certificate(conn, &pos, end) < 0) {
881 			os_free(msg);
882 			return NULL;
883 		}
884 	}
885 
886 	if (tls_write_client_key_exchange(conn, &pos, end) < 0 ||
887 	    (conn->certificate_requested && conn->cred && conn->cred->key &&
888 	     tls_write_client_certificate_verify(conn, &pos, end) < 0) ||
889 	    tls_write_client_change_cipher_spec(conn, &pos, end) < 0 ||
890 	    tls_write_client_finished(conn, &pos, end) < 0) {
891 		os_free(msg);
892 		return NULL;
893 	}
894 
895 	*out_len = pos - msg;
896 
897 	conn->state = SERVER_CHANGE_CIPHER_SPEC;
898 
899 	return msg;
900 }
901 
902 
903 static u8 * tls_send_change_cipher_spec(struct tlsv1_client *conn,
904 					size_t *out_len)
905 {
906 	u8 *msg, *end, *pos;
907 
908 	*out_len = 0;
909 
910 	msg = os_malloc(1000);
911 	if (msg == NULL)
912 		return NULL;
913 
914 	pos = msg;
915 	end = msg + 1000;
916 
917 	if (tls_write_client_change_cipher_spec(conn, &pos, end) < 0 ||
918 	    tls_write_client_finished(conn, &pos, end) < 0) {
919 		os_free(msg);
920 		return NULL;
921 	}
922 
923 	*out_len = pos - msg;
924 
925 	wpa_printf(MSG_DEBUG, "TLSv1: Session resumption completed "
926 		   "successfully");
927 	if (!conn->session_resumed && conn->use_session_ticket)
928 		conn->session_resumed = 1;
929 	conn->state = ESTABLISHED;
930 
931 	return msg;
932 }
933 
934 
935 u8 * tlsv1_client_handshake_write(struct tlsv1_client *conn, size_t *out_len,
936 				  int no_appl_data)
937 {
938 	switch (conn->state) {
939 	case CLIENT_KEY_EXCHANGE:
940 		return tls_send_client_key_exchange(conn, out_len);
941 	case CHANGE_CIPHER_SPEC:
942 		return tls_send_change_cipher_spec(conn, out_len);
943 	case ACK_FINISHED:
944 		wpa_printf(MSG_DEBUG, "TLSv1: Handshake completed "
945 			   "successfully");
946 		conn->state = ESTABLISHED;
947 		*out_len = 0;
948 		if (no_appl_data) {
949 			/* Need to return something to get final TLS ACK. */
950 			return os_malloc(1);
951 		}
952 		return NULL;
953 	default:
954 		wpa_printf(MSG_DEBUG, "TLSv1: Unexpected state %d while "
955 			   "generating reply", conn->state);
956 		return NULL;
957 	}
958 }
959 
960 
961 u8 * tlsv1_client_send_alert(struct tlsv1_client *conn, u8 level,
962 			     u8 description, size_t *out_len)
963 {
964 	u8 *alert, *pos, *length;
965 
966 	wpa_printf(MSG_DEBUG, "TLSv1: Send Alert(%d:%d)", level, description);
967 	*out_len = 0;
968 
969 	alert = os_malloc(10);
970 	if (alert == NULL)
971 		return NULL;
972 
973 	pos = alert;
974 
975 	/* TLSPlaintext */
976 	/* ContentType type */
977 	*pos++ = TLS_CONTENT_TYPE_ALERT;
978 	/* ProtocolVersion version */
979 	WPA_PUT_BE16(pos, conn->rl.tls_version ? conn->rl.tls_version :
980 		     TLS_VERSION);
981 	pos += 2;
982 	/* uint16 length (to be filled) */
983 	length = pos;
984 	pos += 2;
985 	/* opaque fragment[TLSPlaintext.length] */
986 
987 	/* Alert */
988 	/* AlertLevel level */
989 	*pos++ = level;
990 	/* AlertDescription description */
991 	*pos++ = description;
992 
993 	WPA_PUT_BE16(length, pos - length - 2);
994 	*out_len = pos - alert;
995 
996 	return alert;
997 }
998