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      1 /*
      2  * TLSv1 client - write handshake message
      3  * Copyright (c) 2006-2011, Jouni Malinen <j (at) 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 
     51 	wpa_printf(MSG_DEBUG, "TLSv1: Send ClientHello");
     52 	*out_len = 0;
     53 
     54 	os_get_time(&now);
     55 	WPA_PUT_BE32(conn->client_random, now.sec);
     56 	if (random_get_bytes(conn->client_random + 4, TLS_RANDOM_LEN - 4)) {
     57 		wpa_printf(MSG_ERROR, "TLSv1: Could not generate "
     58 			   "client_random");
     59 		return NULL;
     60 	}
     61 	wpa_hexdump(MSG_MSGDUMP, "TLSv1: client_random",
     62 		    conn->client_random, TLS_RANDOM_LEN);
     63 
     64 	len = 100 + conn->num_cipher_suites * 2 + conn->client_hello_ext_len;
     65 	hello = os_malloc(len);
     66 	if (hello == NULL)
     67 		return NULL;
     68 	end = hello + len;
     69 
     70 	rhdr = hello;
     71 	pos = rhdr + TLS_RECORD_HEADER_LEN;
     72 
     73 	/* opaque fragment[TLSPlaintext.length] */
     74 
     75 	/* Handshake */
     76 	hs_start = pos;
     77 	/* HandshakeType msg_type */
     78 	*pos++ = TLS_HANDSHAKE_TYPE_CLIENT_HELLO;
     79 	/* uint24 length (to be filled) */
     80 	hs_length = pos;
     81 	pos += 3;
     82 	/* body - ClientHello */
     83 	/* ProtocolVersion client_version */
     84 	WPA_PUT_BE16(pos, TLS_VERSION);
     85 	pos += 2;
     86 	/* Random random: uint32 gmt_unix_time, opaque random_bytes */
     87 	os_memcpy(pos, conn->client_random, TLS_RANDOM_LEN);
     88 	pos += TLS_RANDOM_LEN;
     89 	/* SessionID session_id */
     90 	*pos++ = conn->session_id_len;
     91 	os_memcpy(pos, conn->session_id, conn->session_id_len);
     92 	pos += conn->session_id_len;
     93 	/* CipherSuite cipher_suites<2..2^16-1> */
     94 	WPA_PUT_BE16(pos, 2 * conn->num_cipher_suites);
     95 	pos += 2;
     96 	for (i = 0; i < conn->num_cipher_suites; i++) {
     97 		WPA_PUT_BE16(pos, conn->cipher_suites[i]);
     98 		pos += 2;
     99 	}
    100 	/* CompressionMethod compression_methods<1..2^8-1> */
    101 	*pos++ = 1;
    102 	*pos++ = TLS_COMPRESSION_NULL;
    103 
    104 	if (conn->client_hello_ext) {
    105 		os_memcpy(pos, conn->client_hello_ext,
    106 			  conn->client_hello_ext_len);
    107 		pos += conn->client_hello_ext_len;
    108 	}
    109 
    110 	WPA_PUT_BE24(hs_length, pos - hs_length - 3);
    111 	tls_verify_hash_add(&conn->verify, hs_start, pos - hs_start);
    112 
    113 	if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_HANDSHAKE,
    114 			      rhdr, end - rhdr, hs_start, pos - hs_start,
    115 			      out_len) < 0) {
    116 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to create TLS record");
    117 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    118 			  TLS_ALERT_INTERNAL_ERROR);
    119 		os_free(hello);
    120 		return NULL;
    121 	}
    122 
    123 	conn->state = SERVER_HELLO;
    124 
    125 	return hello;
    126 }
    127 
    128 
    129 static int tls_write_client_certificate(struct tlsv1_client *conn,
    130 					u8 **msgpos, u8 *end)
    131 {
    132 	u8 *pos, *rhdr, *hs_start, *hs_length, *cert_start;
    133 	size_t rlen;
    134 	struct x509_certificate *cert;
    135 
    136 	pos = *msgpos;
    137 
    138 	wpa_printf(MSG_DEBUG, "TLSv1: Send Certificate");
    139 	rhdr = pos;
    140 	pos += TLS_RECORD_HEADER_LEN;
    141 
    142 	/* opaque fragment[TLSPlaintext.length] */
    143 
    144 	/* Handshake */
    145 	hs_start = pos;
    146 	/* HandshakeType msg_type */
    147 	*pos++ = TLS_HANDSHAKE_TYPE_CERTIFICATE;
    148 	/* uint24 length (to be filled) */
    149 	hs_length = pos;
    150 	pos += 3;
    151 	/* body - Certificate */
    152 	/* uint24 length (to be filled) */
    153 	cert_start = pos;
    154 	pos += 3;
    155 	cert = conn->cred ? conn->cred->cert : NULL;
    156 	while (cert) {
    157 		if (pos + 3 + cert->cert_len > end) {
    158 			wpa_printf(MSG_DEBUG, "TLSv1: Not enough buffer space "
    159 				   "for Certificate (cert_len=%lu left=%lu)",
    160 				   (unsigned long) cert->cert_len,
    161 				   (unsigned long) (end - pos));
    162 			tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    163 				  TLS_ALERT_INTERNAL_ERROR);
    164 			return -1;
    165 		}
    166 		WPA_PUT_BE24(pos, cert->cert_len);
    167 		pos += 3;
    168 		os_memcpy(pos, cert->cert_start, cert->cert_len);
    169 		pos += cert->cert_len;
    170 
    171 		if (x509_certificate_self_signed(cert))
    172 			break;
    173 		cert = x509_certificate_get_subject(conn->cred->trusted_certs,
    174 						    &cert->issuer);
    175 	}
    176 	if (conn->cred == NULL || cert == conn->cred->cert || cert == NULL) {
    177 		/*
    178 		 * Client was not configured with all the needed certificates
    179 		 * to form a full certificate chain. The server may fail to
    180 		 * validate the chain unless it is configured with all the
    181 		 * missing CA certificates.
    182 		 */
    183 		wpa_printf(MSG_DEBUG, "TLSv1: Full client certificate chain "
    184 			   "not configured - validation may fail");
    185 	}
    186 	WPA_PUT_BE24(cert_start, pos - cert_start - 3);
    187 
    188 	WPA_PUT_BE24(hs_length, pos - hs_length - 3);
    189 
    190 	if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_HANDSHAKE,
    191 			      rhdr, end - rhdr, hs_start, pos - hs_start,
    192 			      &rlen) < 0) {
    193 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to generate a record");
    194 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    195 			  TLS_ALERT_INTERNAL_ERROR);
    196 		return -1;
    197 	}
    198 	pos = rhdr + rlen;
    199 
    200 	tls_verify_hash_add(&conn->verify, hs_start, pos - hs_start);
    201 
    202 	*msgpos = pos;
    203 
    204 	return 0;
    205 }
    206 
    207 
    208 static int tlsv1_key_x_anon_dh(struct tlsv1_client *conn, u8 **pos, u8 *end)
    209 {
    210 	/* ClientDiffieHellmanPublic */
    211 	u8 *csecret, *csecret_start, *dh_yc, *shared;
    212 	size_t csecret_len, dh_yc_len, shared_len;
    213 
    214 	csecret_len = conn->dh_p_len;
    215 	csecret = os_malloc(csecret_len);
    216 	if (csecret == NULL) {
    217 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to allocate "
    218 			   "memory for Yc (Diffie-Hellman)");
    219 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    220 			  TLS_ALERT_INTERNAL_ERROR);
    221 		return -1;
    222 	}
    223 	if (random_get_bytes(csecret, csecret_len)) {
    224 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to get random "
    225 			   "data for Diffie-Hellman");
    226 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    227 			  TLS_ALERT_INTERNAL_ERROR);
    228 		os_free(csecret);
    229 		return -1;
    230 	}
    231 
    232 	if (os_memcmp(csecret, conn->dh_p, csecret_len) > 0)
    233 		csecret[0] = 0; /* make sure Yc < p */
    234 
    235 	csecret_start = csecret;
    236 	while (csecret_len > 1 && *csecret_start == 0) {
    237 		csecret_start++;
    238 		csecret_len--;
    239 	}
    240 	wpa_hexdump_key(MSG_DEBUG, "TLSv1: DH client's secret value",
    241 			csecret_start, csecret_len);
    242 
    243 	/* Yc = g^csecret mod p */
    244 	dh_yc_len = conn->dh_p_len;
    245 	dh_yc = os_malloc(dh_yc_len);
    246 	if (dh_yc == NULL) {
    247 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to allocate "
    248 			   "memory for Diffie-Hellman");
    249 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    250 			  TLS_ALERT_INTERNAL_ERROR);
    251 		os_free(csecret);
    252 		return -1;
    253 	}
    254 	if (crypto_mod_exp(conn->dh_g, conn->dh_g_len,
    255 			   csecret_start, csecret_len,
    256 			   conn->dh_p, conn->dh_p_len,
    257 			   dh_yc, &dh_yc_len)) {
    258 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    259 			  TLS_ALERT_INTERNAL_ERROR);
    260 		os_free(csecret);
    261 		os_free(dh_yc);
    262 		return -1;
    263 	}
    264 
    265 	wpa_hexdump(MSG_DEBUG, "TLSv1: DH Yc (client's public value)",
    266 		    dh_yc, dh_yc_len);
    267 
    268 	WPA_PUT_BE16(*pos, dh_yc_len);
    269 	*pos += 2;
    270 	if (*pos + dh_yc_len > end) {
    271 		wpa_printf(MSG_DEBUG, "TLSv1: Not enough room in the "
    272 			   "message buffer for Yc");
    273 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    274 			  TLS_ALERT_INTERNAL_ERROR);
    275 		os_free(csecret);
    276 		os_free(dh_yc);
    277 		return -1;
    278 	}
    279 	os_memcpy(*pos, dh_yc, dh_yc_len);
    280 	*pos += dh_yc_len;
    281 	os_free(dh_yc);
    282 
    283 	shared_len = conn->dh_p_len;
    284 	shared = os_malloc(shared_len);
    285 	if (shared == NULL) {
    286 		wpa_printf(MSG_DEBUG, "TLSv1: Could not allocate memory for "
    287 			   "DH");
    288 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    289 			  TLS_ALERT_INTERNAL_ERROR);
    290 		os_free(csecret);
    291 		return -1;
    292 	}
    293 
    294 	/* shared = Ys^csecret mod p */
    295 	if (crypto_mod_exp(conn->dh_ys, conn->dh_ys_len,
    296 			   csecret_start, csecret_len,
    297 			   conn->dh_p, conn->dh_p_len,
    298 			   shared, &shared_len)) {
    299 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    300 			  TLS_ALERT_INTERNAL_ERROR);
    301 		os_free(csecret);
    302 		os_free(shared);
    303 		return -1;
    304 	}
    305 	wpa_hexdump_key(MSG_DEBUG, "TLSv1: Shared secret from DH key exchange",
    306 			shared, shared_len);
    307 
    308 	os_memset(csecret_start, 0, csecret_len);
    309 	os_free(csecret);
    310 	if (tls_derive_keys(conn, shared, shared_len)) {
    311 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to derive keys");
    312 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    313 			  TLS_ALERT_INTERNAL_ERROR);
    314 		os_free(shared);
    315 		return -1;
    316 	}
    317 	os_memset(shared, 0, shared_len);
    318 	os_free(shared);
    319 	tlsv1_client_free_dh(conn);
    320 	return 0;
    321 }
    322 
    323 
    324 static int tlsv1_key_x_rsa(struct tlsv1_client *conn, u8 **pos, u8 *end)
    325 {
    326 	u8 pre_master_secret[TLS_PRE_MASTER_SECRET_LEN];
    327 	size_t clen;
    328 	int res;
    329 
    330 	if (tls_derive_pre_master_secret(pre_master_secret) < 0 ||
    331 	    tls_derive_keys(conn, pre_master_secret,
    332 			    TLS_PRE_MASTER_SECRET_LEN)) {
    333 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to derive keys");
    334 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    335 			  TLS_ALERT_INTERNAL_ERROR);
    336 		return -1;
    337 	}
    338 
    339 	/* EncryptedPreMasterSecret */
    340 	if (conn->server_rsa_key == NULL) {
    341 		wpa_printf(MSG_DEBUG, "TLSv1: No server RSA key to "
    342 			   "use for encrypting pre-master secret");
    343 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    344 			  TLS_ALERT_INTERNAL_ERROR);
    345 		return -1;
    346 	}
    347 
    348 	/* RSA encrypted value is encoded with PKCS #1 v1.5 block type 2. */
    349 	*pos += 2;
    350 	clen = end - *pos;
    351 	res = crypto_public_key_encrypt_pkcs1_v15(
    352 		conn->server_rsa_key,
    353 		pre_master_secret, TLS_PRE_MASTER_SECRET_LEN,
    354 		*pos, &clen);
    355 	os_memset(pre_master_secret, 0, TLS_PRE_MASTER_SECRET_LEN);
    356 	if (res < 0) {
    357 		wpa_printf(MSG_DEBUG, "TLSv1: RSA encryption failed");
    358 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    359 			  TLS_ALERT_INTERNAL_ERROR);
    360 		return -1;
    361 	}
    362 	WPA_PUT_BE16(*pos - 2, clen);
    363 	wpa_hexdump(MSG_MSGDUMP, "TLSv1: Encrypted pre_master_secret",
    364 		    *pos, clen);
    365 	*pos += clen;
    366 
    367 	return 0;
    368 }
    369 
    370 
    371 static int tls_write_client_key_exchange(struct tlsv1_client *conn,
    372 					 u8 **msgpos, u8 *end)
    373 {
    374 	u8 *pos, *rhdr, *hs_start, *hs_length;
    375 	size_t rlen;
    376 	tls_key_exchange keyx;
    377 	const struct tls_cipher_suite *suite;
    378 
    379 	suite = tls_get_cipher_suite(conn->rl.cipher_suite);
    380 	if (suite == NULL)
    381 		keyx = TLS_KEY_X_NULL;
    382 	else
    383 		keyx = suite->key_exchange;
    384 
    385 	pos = *msgpos;
    386 
    387 	wpa_printf(MSG_DEBUG, "TLSv1: Send ClientKeyExchange");
    388 
    389 	rhdr = pos;
    390 	pos += TLS_RECORD_HEADER_LEN;
    391 
    392 	/* opaque fragment[TLSPlaintext.length] */
    393 
    394 	/* Handshake */
    395 	hs_start = pos;
    396 	/* HandshakeType msg_type */
    397 	*pos++ = TLS_HANDSHAKE_TYPE_CLIENT_KEY_EXCHANGE;
    398 	/* uint24 length (to be filled) */
    399 	hs_length = pos;
    400 	pos += 3;
    401 	/* body - ClientKeyExchange */
    402 	if (keyx == TLS_KEY_X_DH_anon) {
    403 		if (tlsv1_key_x_anon_dh(conn, &pos, end) < 0)
    404 			return -1;
    405 	} else {
    406 		if (tlsv1_key_x_rsa(conn, &pos, end) < 0)
    407 			return -1;
    408 	}
    409 
    410 	WPA_PUT_BE24(hs_length, pos - hs_length - 3);
    411 
    412 	if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_HANDSHAKE,
    413 			      rhdr, end - rhdr, hs_start, pos - hs_start,
    414 			      &rlen) < 0) {
    415 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to create a record");
    416 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    417 			  TLS_ALERT_INTERNAL_ERROR);
    418 		return -1;
    419 	}
    420 	pos = rhdr + rlen;
    421 	tls_verify_hash_add(&conn->verify, hs_start, pos - hs_start);
    422 
    423 	*msgpos = pos;
    424 
    425 	return 0;
    426 }
    427 
    428 
    429 static int tls_write_client_certificate_verify(struct tlsv1_client *conn,
    430 					       u8 **msgpos, u8 *end)
    431 {
    432 	u8 *pos, *rhdr, *hs_start, *hs_length, *signed_start;
    433 	size_t rlen, hlen, clen;
    434 	u8 hash[100], *hpos;
    435 	enum { SIGN_ALG_RSA, SIGN_ALG_DSA } alg = SIGN_ALG_RSA;
    436 
    437 	pos = *msgpos;
    438 
    439 	wpa_printf(MSG_DEBUG, "TLSv1: Send CertificateVerify");
    440 	rhdr = pos;
    441 	pos += TLS_RECORD_HEADER_LEN;
    442 
    443 	/* Handshake */
    444 	hs_start = pos;
    445 	/* HandshakeType msg_type */
    446 	*pos++ = TLS_HANDSHAKE_TYPE_CERTIFICATE_VERIFY;
    447 	/* uint24 length (to be filled) */
    448 	hs_length = pos;
    449 	pos += 3;
    450 
    451 	/*
    452 	 * RFC 2246: 7.4.3 and 7.4.8:
    453 	 * Signature signature
    454 	 *
    455 	 * RSA:
    456 	 * digitally-signed struct {
    457 	 *     opaque md5_hash[16];
    458 	 *     opaque sha_hash[20];
    459 	 * };
    460 	 *
    461 	 * DSA:
    462 	 * digitally-signed struct {
    463 	 *     opaque sha_hash[20];
    464 	 * };
    465 	 *
    466 	 * The hash values are calculated over all handshake messages sent or
    467 	 * received starting at ClientHello up to, but not including, this
    468 	 * CertificateVerify message, including the type and length fields of
    469 	 * the handshake messages.
    470 	 */
    471 
    472 	hpos = hash;
    473 
    474 #ifdef CONFIG_TLSV12
    475 	if (conn->rl.tls_version == TLS_VERSION_1_2) {
    476 		hlen = SHA256_MAC_LEN;
    477 		if (conn->verify.sha256_cert == NULL ||
    478 		    crypto_hash_finish(conn->verify.sha256_cert, hpos, &hlen) <
    479 		    0) {
    480 			conn->verify.sha256_cert = NULL;
    481 			tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    482 				  TLS_ALERT_INTERNAL_ERROR);
    483 			return -1;
    484 		}
    485 		conn->verify.sha256_cert = NULL;
    486 
    487 		/*
    488 		 * RFC 3447, A.2.4 RSASSA-PKCS1-v1_5
    489 		 *
    490 		 * DigestInfo ::= SEQUENCE {
    491 		 *   digestAlgorithm DigestAlgorithm,
    492 		 *   digest OCTET STRING
    493 		 * }
    494 		 *
    495 		 * SHA-256 OID: sha256WithRSAEncryption ::= {pkcs-1 11}
    496 		 *
    497 		 * DER encoded DigestInfo for SHA256 per RFC 3447:
    498 		 * 30 31 30 0d 06 09 60 86 48 01 65 03 04 02 01 05 00 04 20 ||
    499 		 * H
    500 		 */
    501 		os_memmove(hash + 19, hash, hlen);
    502 		hlen += 19;
    503 		os_memcpy(hash, "\x30\x31\x30\x0d\x06\x09\x60\x86\x48\x01\x65"
    504 			  "\x03\x04\x02\x01\x05\x00\x04\x20", 19);
    505 	} else {
    506 #endif /* CONFIG_TLSV12 */
    507 
    508 	if (alg == SIGN_ALG_RSA) {
    509 		hlen = MD5_MAC_LEN;
    510 		if (conn->verify.md5_cert == NULL ||
    511 		    crypto_hash_finish(conn->verify.md5_cert, hpos, &hlen) < 0)
    512 		{
    513 			tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    514 				  TLS_ALERT_INTERNAL_ERROR);
    515 			conn->verify.md5_cert = NULL;
    516 			crypto_hash_finish(conn->verify.sha1_cert, NULL, NULL);
    517 			conn->verify.sha1_cert = NULL;
    518 			return -1;
    519 		}
    520 		hpos += MD5_MAC_LEN;
    521 	} else
    522 		crypto_hash_finish(conn->verify.md5_cert, NULL, NULL);
    523 
    524 	conn->verify.md5_cert = NULL;
    525 	hlen = SHA1_MAC_LEN;
    526 	if (conn->verify.sha1_cert == NULL ||
    527 	    crypto_hash_finish(conn->verify.sha1_cert, hpos, &hlen) < 0) {
    528 		conn->verify.sha1_cert = NULL;
    529 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    530 			  TLS_ALERT_INTERNAL_ERROR);
    531 		return -1;
    532 	}
    533 	conn->verify.sha1_cert = NULL;
    534 
    535 	if (alg == SIGN_ALG_RSA)
    536 		hlen += MD5_MAC_LEN;
    537 
    538 #ifdef CONFIG_TLSV12
    539 	}
    540 #endif /* CONFIG_TLSV12 */
    541 
    542 	wpa_hexdump(MSG_MSGDUMP, "TLSv1: CertificateVerify hash", hash, hlen);
    543 
    544 #ifdef CONFIG_TLSV12
    545 	if (conn->rl.tls_version >= TLS_VERSION_1_2) {
    546 		/*
    547 		 * RFC 5246, 4.7:
    548 		 * TLS v1.2 adds explicit indication of the used signature and
    549 		 * hash algorithms.
    550 		 *
    551 		 * struct {
    552 		 *   HashAlgorithm hash;
    553 		 *   SignatureAlgorithm signature;
    554 		 * } SignatureAndHashAlgorithm;
    555 		 */
    556 		*pos++ = TLS_HASH_ALG_SHA256;
    557 		*pos++ = TLS_SIGN_ALG_RSA;
    558 	}
    559 #endif /* CONFIG_TLSV12 */
    560 
    561 	/*
    562 	 * RFC 2246, 4.7:
    563 	 * In digital signing, one-way hash functions are used as input for a
    564 	 * signing algorithm. A digitally-signed element is encoded as an
    565 	 * opaque vector <0..2^16-1>, where the length is specified by the
    566 	 * signing algorithm and key.
    567 	 *
    568 	 * In RSA signing, a 36-byte structure of two hashes (one SHA and one
    569 	 * MD5) is signed (encrypted with the private key). It is encoded with
    570 	 * PKCS #1 block type 0 or type 1 as described in [PKCS1].
    571 	 */
    572 	signed_start = pos; /* length to be filled */
    573 	pos += 2;
    574 	clen = end - pos;
    575 	if (conn->cred == NULL ||
    576 	    crypto_private_key_sign_pkcs1(conn->cred->key, hash, hlen,
    577 					  pos, &clen) < 0) {
    578 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to sign hash (PKCS #1)");
    579 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    580 			  TLS_ALERT_INTERNAL_ERROR);
    581 		return -1;
    582 	}
    583 	WPA_PUT_BE16(signed_start, clen);
    584 
    585 	pos += clen;
    586 
    587 	WPA_PUT_BE24(hs_length, pos - hs_length - 3);
    588 
    589 	if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_HANDSHAKE,
    590 			      rhdr, end - rhdr, hs_start, pos - hs_start,
    591 			      &rlen) < 0) {
    592 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to generate a record");
    593 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    594 			  TLS_ALERT_INTERNAL_ERROR);
    595 		return -1;
    596 	}
    597 	pos = rhdr + rlen;
    598 
    599 	tls_verify_hash_add(&conn->verify, hs_start, pos - hs_start);
    600 
    601 	*msgpos = pos;
    602 
    603 	return 0;
    604 }
    605 
    606 
    607 static int tls_write_client_change_cipher_spec(struct tlsv1_client *conn,
    608 					       u8 **msgpos, u8 *end)
    609 {
    610 	size_t rlen;
    611 	u8 payload[1];
    612 
    613 	wpa_printf(MSG_DEBUG, "TLSv1: Send ChangeCipherSpec");
    614 
    615 	payload[0] = TLS_CHANGE_CIPHER_SPEC;
    616 
    617 	if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_CHANGE_CIPHER_SPEC,
    618 			      *msgpos, end - *msgpos, payload, sizeof(payload),
    619 			      &rlen) < 0) {
    620 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to create a record");
    621 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    622 			  TLS_ALERT_INTERNAL_ERROR);
    623 		return -1;
    624 	}
    625 
    626 	if (tlsv1_record_change_write_cipher(&conn->rl) < 0) {
    627 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to set write cipher for "
    628 			   "record layer");
    629 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    630 			  TLS_ALERT_INTERNAL_ERROR);
    631 		return -1;
    632 	}
    633 
    634 	*msgpos += rlen;
    635 
    636 	return 0;
    637 }
    638 
    639 
    640 static int tls_write_client_finished(struct tlsv1_client *conn,
    641 				     u8 **msgpos, u8 *end)
    642 {
    643 	u8 *pos, *hs_start;
    644 	size_t rlen, hlen;
    645 	u8 verify_data[1 + 3 + TLS_VERIFY_DATA_LEN];
    646 	u8 hash[MD5_MAC_LEN + SHA1_MAC_LEN];
    647 
    648 	wpa_printf(MSG_DEBUG, "TLSv1: Send Finished");
    649 
    650 	/* Encrypted Handshake Message: Finished */
    651 
    652 #ifdef CONFIG_TLSV12
    653 	if (conn->rl.tls_version >= TLS_VERSION_1_2) {
    654 		hlen = SHA256_MAC_LEN;
    655 		if (conn->verify.sha256_client == NULL ||
    656 		    crypto_hash_finish(conn->verify.sha256_client, hash, &hlen)
    657 		    < 0) {
    658 			tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    659 				  TLS_ALERT_INTERNAL_ERROR);
    660 			conn->verify.sha256_client = NULL;
    661 			return -1;
    662 		}
    663 		conn->verify.sha256_client = NULL;
    664 	} else {
    665 #endif /* CONFIG_TLSV12 */
    666 
    667 	hlen = MD5_MAC_LEN;
    668 	if (conn->verify.md5_client == NULL ||
    669 	    crypto_hash_finish(conn->verify.md5_client, hash, &hlen) < 0) {
    670 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    671 			  TLS_ALERT_INTERNAL_ERROR);
    672 		conn->verify.md5_client = NULL;
    673 		crypto_hash_finish(conn->verify.sha1_client, NULL, NULL);
    674 		conn->verify.sha1_client = NULL;
    675 		return -1;
    676 	}
    677 	conn->verify.md5_client = NULL;
    678 	hlen = SHA1_MAC_LEN;
    679 	if (conn->verify.sha1_client == NULL ||
    680 	    crypto_hash_finish(conn->verify.sha1_client, hash + MD5_MAC_LEN,
    681 			       &hlen) < 0) {
    682 		conn->verify.sha1_client = NULL;
    683 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    684 			  TLS_ALERT_INTERNAL_ERROR);
    685 		return -1;
    686 	}
    687 	conn->verify.sha1_client = NULL;
    688 	hlen = MD5_MAC_LEN + SHA1_MAC_LEN;
    689 
    690 #ifdef CONFIG_TLSV12
    691 	}
    692 #endif /* CONFIG_TLSV12 */
    693 
    694 	if (tls_prf(conn->rl.tls_version,
    695 		    conn->master_secret, TLS_MASTER_SECRET_LEN,
    696 		    "client finished", hash, hlen,
    697 		    verify_data + 1 + 3, TLS_VERIFY_DATA_LEN)) {
    698 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to generate verify_data");
    699 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    700 			  TLS_ALERT_INTERNAL_ERROR);
    701 		return -1;
    702 	}
    703 	wpa_hexdump_key(MSG_DEBUG, "TLSv1: verify_data (client)",
    704 			verify_data + 1 + 3, TLS_VERIFY_DATA_LEN);
    705 
    706 	/* Handshake */
    707 	pos = hs_start = verify_data;
    708 	/* HandshakeType msg_type */
    709 	*pos++ = TLS_HANDSHAKE_TYPE_FINISHED;
    710 	/* uint24 length */
    711 	WPA_PUT_BE24(pos, TLS_VERIFY_DATA_LEN);
    712 	pos += 3;
    713 	pos += TLS_VERIFY_DATA_LEN; /* verify_data already in place */
    714 	tls_verify_hash_add(&conn->verify, hs_start, pos - hs_start);
    715 
    716 	if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_HANDSHAKE,
    717 			      *msgpos, end - *msgpos, hs_start, pos - hs_start,
    718 			      &rlen) < 0) {
    719 		wpa_printf(MSG_DEBUG, "TLSv1: Failed to create a record");
    720 		tls_alert(conn, TLS_ALERT_LEVEL_FATAL,
    721 			  TLS_ALERT_INTERNAL_ERROR);
    722 		return -1;
    723 	}
    724 
    725 	*msgpos += rlen;
    726 
    727 	return 0;
    728 }
    729 
    730 
    731 static u8 * tls_send_client_key_exchange(struct tlsv1_client *conn,
    732 					 size_t *out_len)
    733 {
    734 	u8 *msg, *end, *pos;
    735 	size_t msglen;
    736 
    737 	*out_len = 0;
    738 
    739 	msglen = 2000;
    740 	if (conn->certificate_requested)
    741 		msglen += tls_client_cert_chain_der_len(conn);
    742 
    743 	msg = os_malloc(msglen);
    744 	if (msg == NULL)
    745 		return NULL;
    746 
    747 	pos = msg;
    748 	end = msg + msglen;
    749 
    750 	if (conn->certificate_requested) {
    751 		if (tls_write_client_certificate(conn, &pos, end) < 0) {
    752 			os_free(msg);
    753 			return NULL;
    754 		}
    755 	}
    756 
    757 	if (tls_write_client_key_exchange(conn, &pos, end) < 0 ||
    758 	    (conn->certificate_requested && conn->cred && conn->cred->key &&
    759 	     tls_write_client_certificate_verify(conn, &pos, end) < 0) ||
    760 	    tls_write_client_change_cipher_spec(conn, &pos, end) < 0 ||
    761 	    tls_write_client_finished(conn, &pos, end) < 0) {
    762 		os_free(msg);
    763 		return NULL;
    764 	}
    765 
    766 	*out_len = pos - msg;
    767 
    768 	conn->state = SERVER_CHANGE_CIPHER_SPEC;
    769 
    770 	return msg;
    771 }
    772 
    773 
    774 static u8 * tls_send_change_cipher_spec(struct tlsv1_client *conn,
    775 					size_t *out_len)
    776 {
    777 	u8 *msg, *end, *pos;
    778 
    779 	*out_len = 0;
    780 
    781 	msg = os_malloc(1000);
    782 	if (msg == NULL)
    783 		return NULL;
    784 
    785 	pos = msg;
    786 	end = msg + 1000;
    787 
    788 	if (tls_write_client_change_cipher_spec(conn, &pos, end) < 0 ||
    789 	    tls_write_client_finished(conn, &pos, end) < 0) {
    790 		os_free(msg);
    791 		return NULL;
    792 	}
    793 
    794 	*out_len = pos - msg;
    795 
    796 	wpa_printf(MSG_DEBUG, "TLSv1: Session resumption completed "
    797 		   "successfully");
    798 	conn->state = ESTABLISHED;
    799 
    800 	return msg;
    801 }
    802 
    803 
    804 u8 * tlsv1_client_handshake_write(struct tlsv1_client *conn, size_t *out_len,
    805 				  int no_appl_data)
    806 {
    807 	switch (conn->state) {
    808 	case CLIENT_KEY_EXCHANGE:
    809 		return tls_send_client_key_exchange(conn, out_len);
    810 	case CHANGE_CIPHER_SPEC:
    811 		return tls_send_change_cipher_spec(conn, out_len);
    812 	case ACK_FINISHED:
    813 		wpa_printf(MSG_DEBUG, "TLSv1: Handshake completed "
    814 			   "successfully");
    815 		conn->state = ESTABLISHED;
    816 		*out_len = 0;
    817 		if (no_appl_data) {
    818 			/* Need to return something to get final TLS ACK. */
    819 			return os_malloc(1);
    820 		}
    821 		return NULL;
    822 	default:
    823 		wpa_printf(MSG_DEBUG, "TLSv1: Unexpected state %d while "
    824 			   "generating reply", conn->state);
    825 		return NULL;
    826 	}
    827 }
    828 
    829 
    830 u8 * tlsv1_client_send_alert(struct tlsv1_client *conn, u8 level,
    831 			     u8 description, size_t *out_len)
    832 {
    833 	u8 *alert, *pos, *length;
    834 
    835 	wpa_printf(MSG_DEBUG, "TLSv1: Send Alert(%d:%d)", level, description);
    836 	*out_len = 0;
    837 
    838 	alert = os_malloc(10);
    839 	if (alert == NULL)
    840 		return NULL;
    841 
    842 	pos = alert;
    843 
    844 	/* TLSPlaintext */
    845 	/* ContentType type */
    846 	*pos++ = TLS_CONTENT_TYPE_ALERT;
    847 	/* ProtocolVersion version */
    848 	WPA_PUT_BE16(pos, conn->rl.tls_version ? conn->rl.tls_version :
    849 		     TLS_VERSION);
    850 	pos += 2;
    851 	/* uint16 length (to be filled) */
    852 	length = pos;
    853 	pos += 2;
    854 	/* opaque fragment[TLSPlaintext.length] */
    855 
    856 	/* Alert */
    857 	/* AlertLevel level */
    858 	*pos++ = level;
    859 	/* AlertDescription description */
    860 	*pos++ = description;
    861 
    862 	WPA_PUT_BE16(length, pos - length - 2);
    863 	*out_len = pos - alert;
    864 
    865 	return alert;
    866 }
    867