diff --git a/ChangeLog b/ChangeLog index f4d3fdbbd..2bdaba0b5 100644 --- a/ChangeLog +++ b/ChangeLog @@ -2,6 +2,11 @@ PolarSSL ChangeLog = Version 1.2.16 released 2015-??-?? +Security + * Fix possible client-side NULL pointer dereference (read) when the client + tries to continue the handshake after it failed (a misuse of the API). + (Found by GDS Labs using afl-fuzz.) + Bugfix * Fix unused function warning when using MBEDTLS_MDx_ALT or MBEDTLS_SHAxxx_ALT (found by Henrik) (#239) diff --git a/library/ssl_cli.c b/library/ssl_cli.c index db9e17955..f4b1c4d58 100644 --- a/library/ssl_cli.c +++ b/library/ssl_cli.c @@ -693,6 +693,12 @@ static int ssl_parse_server_key_exchange( ssl_context *ssl ) return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE ); } + if( ssl->session_negotiate->peer_cert == NULL ) + { + SSL_DEBUG_MSG( 2, ( "certificate required" ) ); + return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE ); + } + SSL_DEBUG_BUF( 3, "server key exchange", ssl->in_msg + 4, ssl->in_hslen - 4 ); /* @@ -1119,6 +1125,12 @@ static int ssl_write_client_key_exchange( ssl_context *ssl ) /* * RSA key exchange -- send rsa_public(pkcs1 v1.5(premaster)) */ + if( ssl->session_negotiate->peer_cert == NULL ) + { + SSL_DEBUG_MSG( 2, ( "certificate required" ) ); + return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE ); + } + ssl->handshake->premaster[0] = (unsigned char) ssl->max_major_ver; ssl->handshake->premaster[1] = (unsigned char) ssl->max_minor_ver; ssl->handshake->pmslen = 48; diff --git a/library/ssl_cli.c.orig b/library/ssl_cli.c.orig new file mode 100644 index 000000000..7f46cbb33 --- /dev/null +++ b/library/ssl_cli.c.orig @@ -0,0 +1,2876 @@ +/* + * SSLv3/TLSv1 client-side functions + * + * Copyright (C) 2006-2014, ARM Limited, All Rights Reserved + * + * This file is part of mbed TLS (https://tls.mbed.org) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#if !defined(POLARSSL_CONFIG_FILE) +#include "polarssl/config.h" +#else +#include POLARSSL_CONFIG_FILE +#endif + +#if defined(POLARSSL_SSL_CLI_C) + +#include "polarssl/debug.h" +#include "polarssl/ssl.h" + +#include + +#if defined(POLARSSL_PLATFORM_C) +#include "polarssl/platform.h" +#else +#include +#define polarssl_malloc malloc +#define polarssl_free free +#endif + +#if defined(_MSC_VER) && !defined(EFIX64) && !defined(EFI32) +#include +typedef UINT32 uint32_t; +#else +#include +#endif + +#if defined(POLARSSL_HAVE_TIME) +#include +#endif + +#if defined(POLARSSL_SSL_SESSION_TICKETS) +/* Implementation that should never be optimized out by the compiler */ +static void polarssl_zeroize( void *v, size_t n ) { + volatile unsigned char *p = v; while( n-- ) *p++ = 0; +} +#endif + +#if defined(POLARSSL_SSL_SERVER_NAME_INDICATION) +static void ssl_write_hostname_ext( ssl_context *ssl, + unsigned char *buf, + size_t *olen ) +{ + unsigned char *p = buf; + + *olen = 0; + + if( ssl->hostname == NULL ) + return; + + SSL_DEBUG_MSG( 3, ( "client hello, adding server name extension: %s", + ssl->hostname ) ); + + /* + * struct { + * NameType name_type; + * select (name_type) { + * case host_name: HostName; + * } name; + * } ServerName; + * + * enum { + * host_name(0), (255) + * } NameType; + * + * opaque HostName<1..2^16-1>; + * + * struct { + * ServerName server_name_list<1..2^16-1> + * } ServerNameList; + */ + *p++ = (unsigned char)( ( TLS_EXT_SERVERNAME >> 8 ) & 0xFF ); + *p++ = (unsigned char)( ( TLS_EXT_SERVERNAME ) & 0xFF ); + + *p++ = (unsigned char)( ( (ssl->hostname_len + 5) >> 8 ) & 0xFF ); + *p++ = (unsigned char)( ( (ssl->hostname_len + 5) ) & 0xFF ); + + *p++ = (unsigned char)( ( (ssl->hostname_len + 3) >> 8 ) & 0xFF ); + *p++ = (unsigned char)( ( (ssl->hostname_len + 3) ) & 0xFF ); + + *p++ = (unsigned char)( ( TLS_EXT_SERVERNAME_HOSTNAME ) & 0xFF ); + *p++ = (unsigned char)( ( ssl->hostname_len >> 8 ) & 0xFF ); + *p++ = (unsigned char)( ( ssl->hostname_len ) & 0xFF ); + + memcpy( p, ssl->hostname, ssl->hostname_len ); + + *olen = ssl->hostname_len + 9; +} +#endif /* POLARSSL_SSL_SERVER_NAME_INDICATION */ + +#if defined(POLARSSL_SSL_RENEGOTIATION) +static void ssl_write_renegotiation_ext( ssl_context *ssl, + unsigned char *buf, + size_t *olen ) +{ + unsigned char *p = buf; + + *olen = 0; + + if( ssl->renegotiation != SSL_RENEGOTIATION ) + return; + + SSL_DEBUG_MSG( 3, ( "client hello, adding renegotiation extension" ) ); + + /* + * Secure renegotiation + */ + *p++ = (unsigned char)( ( TLS_EXT_RENEGOTIATION_INFO >> 8 ) & 0xFF ); + *p++ = (unsigned char)( ( TLS_EXT_RENEGOTIATION_INFO ) & 0xFF ); + + *p++ = 0x00; + *p++ = ( ssl->verify_data_len + 1 ) & 0xFF; + *p++ = ssl->verify_data_len & 0xFF; + + memcpy( p, ssl->own_verify_data, ssl->verify_data_len ); + + *olen = 5 + ssl->verify_data_len; +} +#endif /* POLARSSL_SSL_RENEGOTIATION */ + +/* + * Only if we handle at least one key exchange that needs signatures. + */ +#if defined(POLARSSL_SSL_PROTO_TLS1_2) && \ + defined(POLARSSL_KEY_EXCHANGE__WITH_CERT__ENABLED) +static void ssl_write_signature_algorithms_ext( ssl_context *ssl, + unsigned char *buf, + size_t *olen ) +{ + unsigned char *p = buf; + size_t sig_alg_len = 0; +#if defined(POLARSSL_RSA_C) || defined(POLARSSL_ECDSA_C) + unsigned char *sig_alg_list = buf + 6; +#endif + + *olen = 0; + + if( ssl->max_minor_ver != SSL_MINOR_VERSION_3 ) + return; + + SSL_DEBUG_MSG( 3, ( "client hello, adding signature_algorithms extension" ) ); + + /* + * Prepare signature_algorithms extension (TLS 1.2) + */ +#if defined(POLARSSL_RSA_C) +#if defined(POLARSSL_SHA512_C) + sig_alg_list[sig_alg_len++] = SSL_HASH_SHA512; + sig_alg_list[sig_alg_len++] = SSL_SIG_RSA; + sig_alg_list[sig_alg_len++] = SSL_HASH_SHA384; + sig_alg_list[sig_alg_len++] = SSL_SIG_RSA; +#endif +#if defined(POLARSSL_SHA256_C) + sig_alg_list[sig_alg_len++] = SSL_HASH_SHA256; + sig_alg_list[sig_alg_len++] = SSL_SIG_RSA; + sig_alg_list[sig_alg_len++] = SSL_HASH_SHA224; + sig_alg_list[sig_alg_len++] = SSL_SIG_RSA; +#endif +#if defined(POLARSSL_SHA1_C) + sig_alg_list[sig_alg_len++] = SSL_HASH_SHA1; + sig_alg_list[sig_alg_len++] = SSL_SIG_RSA; +#endif +#if defined(POLARSSL_MD5_C) + sig_alg_list[sig_alg_len++] = SSL_HASH_MD5; + sig_alg_list[sig_alg_len++] = SSL_SIG_RSA; +#endif +#endif /* POLARSSL_RSA_C */ +#if defined(POLARSSL_ECDSA_C) +#if defined(POLARSSL_SHA512_C) + sig_alg_list[sig_alg_len++] = SSL_HASH_SHA512; + sig_alg_list[sig_alg_len++] = SSL_SIG_ECDSA; + sig_alg_list[sig_alg_len++] = SSL_HASH_SHA384; + sig_alg_list[sig_alg_len++] = SSL_SIG_ECDSA; +#endif +#if defined(POLARSSL_SHA256_C) + sig_alg_list[sig_alg_len++] = SSL_HASH_SHA256; + sig_alg_list[sig_alg_len++] = SSL_SIG_ECDSA; + sig_alg_list[sig_alg_len++] = SSL_HASH_SHA224; + sig_alg_list[sig_alg_len++] = SSL_SIG_ECDSA; +#endif +#if defined(POLARSSL_SHA1_C) + sig_alg_list[sig_alg_len++] = SSL_HASH_SHA1; + sig_alg_list[sig_alg_len++] = SSL_SIG_ECDSA; +#endif +#if defined(POLARSSL_MD5_C) + sig_alg_list[sig_alg_len++] = SSL_HASH_MD5; + sig_alg_list[sig_alg_len++] = SSL_SIG_ECDSA; +#endif +#endif /* POLARSSL_ECDSA_C */ + + /* + * enum { + * none(0), md5(1), sha1(2), sha224(3), sha256(4), sha384(5), + * sha512(6), (255) + * } HashAlgorithm; + * + * enum { anonymous(0), rsa(1), dsa(2), ecdsa(3), (255) } + * SignatureAlgorithm; + * + * struct { + * HashAlgorithm hash; + * SignatureAlgorithm signature; + * } SignatureAndHashAlgorithm; + * + * SignatureAndHashAlgorithm + * supported_signature_algorithms<2..2^16-2>; + */ + *p++ = (unsigned char)( ( TLS_EXT_SIG_ALG >> 8 ) & 0xFF ); + *p++ = (unsigned char)( ( TLS_EXT_SIG_ALG ) & 0xFF ); + + *p++ = (unsigned char)( ( ( sig_alg_len + 2 ) >> 8 ) & 0xFF ); + *p++ = (unsigned char)( ( ( sig_alg_len + 2 ) ) & 0xFF ); + + *p++ = (unsigned char)( ( sig_alg_len >> 8 ) & 0xFF ); + *p++ = (unsigned char)( ( sig_alg_len ) & 0xFF ); + + *olen = 6 + sig_alg_len; +} +#endif /* POLARSSL_SSL_PROTO_TLS1_2 && + POLARSSL_KEY_EXCHANGE__WITH_CERT__ENABLED */ + +#if defined(POLARSSL_ECDH_C) || defined(POLARSSL_ECDSA_C) +static void ssl_write_supported_elliptic_curves_ext( ssl_context *ssl, + unsigned char *buf, + size_t *olen ) +{ + unsigned char *p = buf; + unsigned char *elliptic_curve_list = p + 6; + size_t elliptic_curve_len = 0; + const ecp_curve_info *info; +#if defined(POLARSSL_SSL_SET_CURVES) + const ecp_group_id *grp_id; +#else + ((void) ssl); +#endif + + *olen = 0; + + SSL_DEBUG_MSG( 3, ( "client hello, adding supported_elliptic_curves extension" ) ); + +#if defined(POLARSSL_SSL_SET_CURVES) + for( grp_id = ssl->curve_list; *grp_id != POLARSSL_ECP_DP_NONE; grp_id++ ) + { + info = ecp_curve_info_from_grp_id( *grp_id ); +#else + for( info = ecp_curve_list(); info->grp_id != POLARSSL_ECP_DP_NONE; info++ ) + { +#endif + + elliptic_curve_list[elliptic_curve_len++] = info->tls_id >> 8; + elliptic_curve_list[elliptic_curve_len++] = info->tls_id & 0xFF; + } + + if( elliptic_curve_len == 0 ) + return; + + *p++ = (unsigned char)( ( TLS_EXT_SUPPORTED_ELLIPTIC_CURVES >> 8 ) & 0xFF ); + *p++ = (unsigned char)( ( TLS_EXT_SUPPORTED_ELLIPTIC_CURVES ) & 0xFF ); + + *p++ = (unsigned char)( ( ( elliptic_curve_len + 2 ) >> 8 ) & 0xFF ); + *p++ = (unsigned char)( ( ( elliptic_curve_len + 2 ) ) & 0xFF ); + + *p++ = (unsigned char)( ( ( elliptic_curve_len ) >> 8 ) & 0xFF ); + *p++ = (unsigned char)( ( ( elliptic_curve_len ) ) & 0xFF ); + + *olen = 6 + elliptic_curve_len; +} + +static void ssl_write_supported_point_formats_ext( ssl_context *ssl, + unsigned char *buf, + size_t *olen ) +{ + unsigned char *p = buf; + ((void) ssl); + + *olen = 0; + + SSL_DEBUG_MSG( 3, ( "client hello, adding supported_point_formats extension" ) ); + + *p++ = (unsigned char)( ( TLS_EXT_SUPPORTED_POINT_FORMATS >> 8 ) & 0xFF ); + *p++ = (unsigned char)( ( TLS_EXT_SUPPORTED_POINT_FORMATS ) & 0xFF ); + + *p++ = 0x00; + *p++ = 2; + + *p++ = 1; + *p++ = POLARSSL_ECP_PF_UNCOMPRESSED; + + *olen = 6; +} +#endif /* POLARSSL_ECDH_C || POLARSSL_ECDSA_C */ + +#if defined(POLARSSL_SSL_MAX_FRAGMENT_LENGTH) +static void ssl_write_max_fragment_length_ext( ssl_context *ssl, + unsigned char *buf, + size_t *olen ) +{ + unsigned char *p = buf; + + if( ssl->mfl_code == SSL_MAX_FRAG_LEN_NONE ) { + *olen = 0; + return; + } + + SSL_DEBUG_MSG( 3, ( "client hello, adding max_fragment_length extension" ) ); + + *p++ = (unsigned char)( ( TLS_EXT_MAX_FRAGMENT_LENGTH >> 8 ) & 0xFF ); + *p++ = (unsigned char)( ( TLS_EXT_MAX_FRAGMENT_LENGTH ) & 0xFF ); + + *p++ = 0x00; + *p++ = 1; + + *p++ = ssl->mfl_code; + + *olen = 5; +} +#endif /* POLARSSL_SSL_MAX_FRAGMENT_LENGTH */ + +#if defined(POLARSSL_SSL_TRUNCATED_HMAC) +static void ssl_write_truncated_hmac_ext( ssl_context *ssl, + unsigned char *buf, size_t *olen ) +{ + unsigned char *p = buf; + + if( ssl->trunc_hmac == SSL_TRUNC_HMAC_DISABLED ) + { + *olen = 0; + return; + } + + SSL_DEBUG_MSG( 3, ( "client hello, adding truncated_hmac extension" ) ); + + *p++ = (unsigned char)( ( TLS_EXT_TRUNCATED_HMAC >> 8 ) & 0xFF ); + *p++ = (unsigned char)( ( TLS_EXT_TRUNCATED_HMAC ) & 0xFF ); + + *p++ = 0x00; + *p++ = 0x00; + + *olen = 4; +} +#endif /* POLARSSL_SSL_TRUNCATED_HMAC */ + +#if defined(POLARSSL_SSL_ENCRYPT_THEN_MAC) +static void ssl_write_encrypt_then_mac_ext( ssl_context *ssl, + unsigned char *buf, size_t *olen ) +{ + unsigned char *p = buf; + + if( ssl->encrypt_then_mac == SSL_ETM_DISABLED || + ssl->max_minor_ver == SSL_MINOR_VERSION_0 ) + { + *olen = 0; + return; + } + + SSL_DEBUG_MSG( 3, ( "client hello, adding encrypt_then_mac " + "extension" ) ); + + *p++ = (unsigned char)( ( TLS_EXT_ENCRYPT_THEN_MAC >> 8 ) & 0xFF ); + *p++ = (unsigned char)( ( TLS_EXT_ENCRYPT_THEN_MAC ) & 0xFF ); + + *p++ = 0x00; + *p++ = 0x00; + + *olen = 4; +} +#endif /* POLARSSL_SSL_ENCRYPT_THEN_MAC */ + +#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET) +static void ssl_write_extended_ms_ext( ssl_context *ssl, + unsigned char *buf, size_t *olen ) +{ + unsigned char *p = buf; + + if( ssl->extended_ms == SSL_EXTENDED_MS_DISABLED || + ssl->max_minor_ver == SSL_MINOR_VERSION_0 ) + { + *olen = 0; + return; + } + + SSL_DEBUG_MSG( 3, ( "client hello, adding extended_master_secret " + "extension" ) ); + + *p++ = (unsigned char)( ( TLS_EXT_EXTENDED_MASTER_SECRET >> 8 ) & 0xFF ); + *p++ = (unsigned char)( ( TLS_EXT_EXTENDED_MASTER_SECRET ) & 0xFF ); + + *p++ = 0x00; + *p++ = 0x00; + + *olen = 4; +} +#endif /* POLARSSL_SSL_EXTENDED_MASTER_SECRET */ + +#if defined(POLARSSL_SSL_SESSION_TICKETS) +static void ssl_write_session_ticket_ext( ssl_context *ssl, + unsigned char *buf, size_t *olen ) +{ + unsigned char *p = buf; + size_t tlen = ssl->session_negotiate->ticket_len; + + if( ssl->session_tickets == SSL_SESSION_TICKETS_DISABLED ) + { + *olen = 0; + return; + } + + SSL_DEBUG_MSG( 3, ( "client hello, adding session ticket extension" ) ); + + *p++ = (unsigned char)( ( TLS_EXT_SESSION_TICKET >> 8 ) & 0xFF ); + *p++ = (unsigned char)( ( TLS_EXT_SESSION_TICKET ) & 0xFF ); + + *p++ = (unsigned char)( ( tlen >> 8 ) & 0xFF ); + *p++ = (unsigned char)( ( tlen ) & 0xFF ); + + *olen = 4; + + if( ssl->session_negotiate->ticket == NULL || + ssl->session_negotiate->ticket_len == 0 ) + { + return; + } + + SSL_DEBUG_MSG( 3, ( "sending session ticket of length %d", tlen ) ); + + memcpy( p, ssl->session_negotiate->ticket, tlen ); + + *olen += tlen; +} +#endif /* POLARSSL_SSL_SESSION_TICKETS */ + +#if defined(POLARSSL_SSL_ALPN) +static void ssl_write_alpn_ext( ssl_context *ssl, + unsigned char *buf, size_t *olen ) +{ + unsigned char *p = buf; + const char **cur; + + if( ssl->alpn_list == NULL ) + { + *olen = 0; + return; + } + + SSL_DEBUG_MSG( 3, ( "client hello, adding alpn extension" ) ); + + *p++ = (unsigned char)( ( TLS_EXT_ALPN >> 8 ) & 0xFF ); + *p++ = (unsigned char)( ( TLS_EXT_ALPN ) & 0xFF ); + + /* + * opaque ProtocolName<1..2^8-1>; + * + * struct { + * ProtocolName protocol_name_list<2..2^16-1> + * } ProtocolNameList; + */ + + /* Skip writing extension and list length for now */ + p += 4; + + for( cur = ssl->alpn_list; *cur != NULL; cur++ ) + { + *p = (unsigned char)( strlen( *cur ) & 0xFF ); + memcpy( p + 1, *cur, *p ); + p += 1 + *p; + } + + *olen = p - buf; + + /* List length = olen - 2 (ext_type) - 2 (ext_len) - 2 (list_len) */ + buf[4] = (unsigned char)( ( ( *olen - 6 ) >> 8 ) & 0xFF ); + buf[5] = (unsigned char)( ( ( *olen - 6 ) ) & 0xFF ); + + /* Extension length = olen - 2 (ext_type) - 2 (ext_len) */ + buf[2] = (unsigned char)( ( ( *olen - 4 ) >> 8 ) & 0xFF ); + buf[3] = (unsigned char)( ( ( *olen - 4 ) ) & 0xFF ); +} +#endif /* POLARSSL_SSL_ALPN */ + +static int ssl_write_client_hello( ssl_context *ssl ) +{ + int ret; + size_t i, n, olen, ext_len = 0; + unsigned char *buf; + unsigned char *p, *q; +#if defined(POLARSSL_HAVE_TIME) + time_t t; +#endif + const int *ciphersuites; + const ssl_ciphersuite_t *ciphersuite_info; + + SSL_DEBUG_MSG( 2, ( "=> write client hello" ) ); + + if( ssl->f_rng == NULL ) + { + SSL_DEBUG_MSG( 1, ( "no RNG provided") ); + return( POLARSSL_ERR_SSL_NO_RNG ); + } + +#if defined(POLARSSL_SSL_RENEGOTIATION) + if( ssl->renegotiation == SSL_INITIAL_HANDSHAKE ) +#endif + { + ssl->major_ver = ssl->min_major_ver; + ssl->minor_ver = ssl->min_minor_ver; + } + + if( ssl->max_major_ver == 0 && ssl->max_minor_ver == 0 ) + { + ssl->max_major_ver = SSL_MAX_MAJOR_VERSION; + ssl->max_minor_ver = SSL_MAX_MINOR_VERSION; + } + + /* + * 0 . 0 handshake type + * 1 . 3 handshake length + * 4 . 5 highest version supported + * 6 . 9 current UNIX time + * 10 . 37 random bytes + */ + buf = ssl->out_msg; + p = buf + 4; + + *p++ = (unsigned char) ssl->max_major_ver; + *p++ = (unsigned char) ssl->max_minor_ver; + + SSL_DEBUG_MSG( 3, ( "client hello, max version: [%d:%d]", + buf[4], buf[5] ) ); + +#if defined(POLARSSL_HAVE_TIME) + t = time( NULL ); + *p++ = (unsigned char)( t >> 24 ); + *p++ = (unsigned char)( t >> 16 ); + *p++ = (unsigned char)( t >> 8 ); + *p++ = (unsigned char)( t ); + + SSL_DEBUG_MSG( 3, ( "client hello, current time: %lu", t ) ); +#else + if( ( ret = ssl->f_rng( ssl->p_rng, p, 4 ) ) != 0 ) + return( ret ); + + p += 4; +#endif /* POLARSSL_HAVE_TIME */ + + if( ( ret = ssl->f_rng( ssl->p_rng, p, 28 ) ) != 0 ) + return( ret ); + + p += 28; + + memcpy( ssl->handshake->randbytes, buf + 6, 32 ); + + SSL_DEBUG_BUF( 3, "client hello, random bytes", buf + 6, 32 ); + + /* + * 38 . 38 session id length + * 39 . 39+n session id + * 40+n . 41+n ciphersuitelist length + * 42+n . .. ciphersuitelist + * .. . .. compression methods length + * .. . .. compression methods + * .. . .. extensions length + * .. . .. extensions + */ + n = ssl->session_negotiate->length; + + if( n < 16 || n > 32 || +#if defined(POLARSSL_SSL_RENEGOTIATION) + ssl->renegotiation != SSL_INITIAL_HANDSHAKE || +#endif + ssl->handshake->resume == 0 ) + { + n = 0; + } + +#if defined(POLARSSL_SSL_SESSION_TICKETS) + /* + * RFC 5077 section 3.4: "When presenting a ticket, the client MAY + * generate and include a Session ID in the TLS ClientHello." + */ +#if defined(POLARSSL_SSL_RENEGOTIATION) + if( ssl->renegotiation == SSL_INITIAL_HANDSHAKE ) +#endif + { + if( ssl->session_negotiate->ticket != NULL && + ssl->session_negotiate->ticket_len != 0 ) + { + ret = ssl->f_rng( ssl->p_rng, ssl->session_negotiate->id, 32 ); + + if( ret != 0 ) + return( ret ); + + ssl->session_negotiate->length = n = 32; + } + } +#endif /* POLARSSL_SSL_SESSION_TICKETS */ + + *p++ = (unsigned char) n; + + for( i = 0; i < n; i++ ) + *p++ = ssl->session_negotiate->id[i]; + + SSL_DEBUG_MSG( 3, ( "client hello, session id len.: %d", n ) ); + SSL_DEBUG_BUF( 3, "client hello, session id", buf + 39, n ); + + ciphersuites = ssl->ciphersuite_list[ssl->minor_ver]; + n = 0; + q = p; + + // Skip writing ciphersuite length for now + p += 2; + + for( i = 0; ciphersuites[i] != 0; i++ ) + { + ciphersuite_info = ssl_ciphersuite_from_id( ciphersuites[i] ); + + if( ciphersuite_info == NULL ) + continue; + + if( ciphersuite_info->min_minor_ver > ssl->max_minor_ver || + ciphersuite_info->max_minor_ver < ssl->min_minor_ver ) + continue; + + if( ssl->arc4_disabled == SSL_ARC4_DISABLED && + ciphersuite_info->cipher == POLARSSL_CIPHER_ARC4_128 ) + continue; + + SSL_DEBUG_MSG( 3, ( "client hello, add ciphersuite: %2d", + ciphersuites[i] ) ); + + n++; + *p++ = (unsigned char)( ciphersuites[i] >> 8 ); + *p++ = (unsigned char)( ciphersuites[i] ); + } + + /* + * Add TLS_EMPTY_RENEGOTIATION_INFO_SCSV + */ +#if defined(POLARSSL_SSL_RENEGOTIATION) + if( ssl->renegotiation == SSL_INITIAL_HANDSHAKE ) +#endif + { + *p++ = (unsigned char)( SSL_EMPTY_RENEGOTIATION_INFO >> 8 ); + *p++ = (unsigned char)( SSL_EMPTY_RENEGOTIATION_INFO ); + n++; + } + + /* Some versions of OpenSSL don't handle it correctly if not at end */ +#if defined(POLARSSL_SSL_FALLBACK_SCSV) + if( ssl->fallback == SSL_IS_FALLBACK ) + { + SSL_DEBUG_MSG( 3, ( "adding FALLBACK_SCSV" ) ); + *p++ = (unsigned char)( SSL_FALLBACK_SCSV >> 8 ); + *p++ = (unsigned char)( SSL_FALLBACK_SCSV ); + n++; + } +#endif + + *q++ = (unsigned char)( n >> 7 ); + *q++ = (unsigned char)( n << 1 ); + + SSL_DEBUG_MSG( 3, ( "client hello, got %d ciphersuites", n ) ); + + +#if defined(POLARSSL_ZLIB_SUPPORT) + SSL_DEBUG_MSG( 3, ( "client hello, compress len.: %d", 2 ) ); + SSL_DEBUG_MSG( 3, ( "client hello, compress alg.: %d %d", + SSL_COMPRESS_DEFLATE, SSL_COMPRESS_NULL ) ); + + *p++ = 2; + *p++ = SSL_COMPRESS_DEFLATE; + *p++ = SSL_COMPRESS_NULL; +#else + SSL_DEBUG_MSG( 3, ( "client hello, compress len.: %d", 1 ) ); + SSL_DEBUG_MSG( 3, ( "client hello, compress alg.: %d", SSL_COMPRESS_NULL ) ); + + *p++ = 1; + *p++ = SSL_COMPRESS_NULL; +#endif /* POLARSSL_ZLIB_SUPPORT */ + + // First write extensions, then the total length + // +#if defined(POLARSSL_SSL_SERVER_NAME_INDICATION) + ssl_write_hostname_ext( ssl, p + 2 + ext_len, &olen ); + ext_len += olen; +#endif + +#if defined(POLARSSL_SSL_RENEGOTIATION) + ssl_write_renegotiation_ext( ssl, p + 2 + ext_len, &olen ); + ext_len += olen; +#endif + +#if defined(POLARSSL_SSL_PROTO_TLS1_2) && \ + defined(POLARSSL_KEY_EXCHANGE__WITH_CERT__ENABLED) + ssl_write_signature_algorithms_ext( ssl, p + 2 + ext_len, &olen ); + ext_len += olen; +#endif + +#if defined(POLARSSL_ECDH_C) || defined(POLARSSL_ECDSA_C) + ssl_write_supported_elliptic_curves_ext( ssl, p + 2 + ext_len, &olen ); + ext_len += olen; + + ssl_write_supported_point_formats_ext( ssl, p + 2 + ext_len, &olen ); + ext_len += olen; +#endif + +#if defined(POLARSSL_SSL_MAX_FRAGMENT_LENGTH) + ssl_write_max_fragment_length_ext( ssl, p + 2 + ext_len, &olen ); + ext_len += olen; +#endif + +#if defined(POLARSSL_SSL_TRUNCATED_HMAC) + ssl_write_truncated_hmac_ext( ssl, p + 2 + ext_len, &olen ); + ext_len += olen; +#endif + +#if defined(POLARSSL_SSL_ENCRYPT_THEN_MAC) + ssl_write_encrypt_then_mac_ext( ssl, p + 2 + ext_len, &olen ); + ext_len += olen; +#endif + +#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET) + ssl_write_extended_ms_ext( ssl, p + 2 + ext_len, &olen ); + ext_len += olen; +#endif + +#if defined(POLARSSL_SSL_SESSION_TICKETS) + ssl_write_session_ticket_ext( ssl, p + 2 + ext_len, &olen ); + ext_len += olen; +#endif + +#if defined(POLARSSL_SSL_ALPN) + ssl_write_alpn_ext( ssl, p + 2 + ext_len, &olen ); + ext_len += olen; +#endif + + /* olen unused if all extensions are disabled */ + ((void) olen); + + SSL_DEBUG_MSG( 3, ( "client hello, total extension length: %d", + ext_len ) ); + + if( ext_len > 0 ) + { + *p++ = (unsigned char)( ( ext_len >> 8 ) & 0xFF ); + *p++ = (unsigned char)( ( ext_len ) & 0xFF ); + p += ext_len; + } + + ssl->out_msglen = p - buf; + ssl->out_msgtype = SSL_MSG_HANDSHAKE; + ssl->out_msg[0] = SSL_HS_CLIENT_HELLO; + + ssl->state++; + + if( ( ret = ssl_write_record( ssl ) ) != 0 ) + { + SSL_DEBUG_RET( 1, "ssl_write_record", ret ); + return( ret ); + } + + SSL_DEBUG_MSG( 2, ( "<= write client hello" ) ); + + return( 0 ); +} + +static int ssl_parse_renegotiation_info( ssl_context *ssl, + const unsigned char *buf, + size_t len ) +{ + int ret; + +#if defined(POLARSSL_SSL_RENEGOTIATION) + if( ssl->renegotiation != SSL_INITIAL_HANDSHAKE ) + { + /* Check verify-data in constant-time. The length OTOH is no secret */ + if( len != 1 + ssl->verify_data_len * 2 || + buf[0] != ssl->verify_data_len * 2 || + safer_memcmp( buf + 1, + ssl->own_verify_data, ssl->verify_data_len ) != 0 || + safer_memcmp( buf + 1 + ssl->verify_data_len, + ssl->peer_verify_data, ssl->verify_data_len ) != 0 ) + { + SSL_DEBUG_MSG( 1, ( "non-matching renegotiation info" ) ); + + if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 ) + return( ret ); + + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); + } + } + else +#endif /* POLARSSL_SSL_RENEGOTIATION */ + { + if( len != 1 || buf[0] != 0x00 ) + { + SSL_DEBUG_MSG( 1, ( "non-zero length renegotiation info" ) ); + + if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 ) + return( ret ); + + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); + } + + ssl->secure_renegotiation = SSL_SECURE_RENEGOTIATION; + } + + return( 0 ); +} + +#if defined(POLARSSL_SSL_MAX_FRAGMENT_LENGTH) +static int ssl_parse_max_fragment_length_ext( ssl_context *ssl, + const unsigned char *buf, + size_t len ) +{ + /* + * server should use the extension only if we did, + * and if so the server's value should match ours (and len is always 1) + */ + if( ssl->mfl_code == SSL_MAX_FRAG_LEN_NONE || + len != 1 || + buf[0] != ssl->mfl_code ) + { + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); + } + + return( 0 ); +} +#endif /* POLARSSL_SSL_MAX_FRAGMENT_LENGTH */ + +#if defined(POLARSSL_SSL_TRUNCATED_HMAC) +static int ssl_parse_truncated_hmac_ext( ssl_context *ssl, + const unsigned char *buf, + size_t len ) +{ + if( ssl->trunc_hmac == SSL_TRUNC_HMAC_DISABLED || + len != 0 ) + { + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); + } + + ((void) buf); + + ssl->session_negotiate->trunc_hmac = SSL_TRUNC_HMAC_ENABLED; + + return( 0 ); +} +#endif /* POLARSSL_SSL_TRUNCATED_HMAC */ + +#if defined(POLARSSL_SSL_ENCRYPT_THEN_MAC) +static int ssl_parse_encrypt_then_mac_ext( ssl_context *ssl, + const unsigned char *buf, + size_t len ) +{ + if( ssl->encrypt_then_mac == SSL_ETM_DISABLED || + ssl->minor_ver == SSL_MINOR_VERSION_0 || + len != 0 ) + { + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); + } + + ((void) buf); + + ssl->session_negotiate->encrypt_then_mac = SSL_ETM_ENABLED; + + return( 0 ); +} +#endif /* POLARSSL_SSL_ENCRYPT_THEN_MAC */ + +#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET) +static int ssl_parse_extended_ms_ext( ssl_context *ssl, + const unsigned char *buf, + size_t len ) +{ + if( ssl->extended_ms == SSL_EXTENDED_MS_DISABLED || + ssl->minor_ver == SSL_MINOR_VERSION_0 || + len != 0 ) + { + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); + } + + ((void) buf); + + ssl->handshake->extended_ms = SSL_EXTENDED_MS_ENABLED; + + return( 0 ); +} +#endif /* POLARSSL_SSL_EXTENDED_MASTER_SECRET */ + +#if defined(POLARSSL_SSL_SESSION_TICKETS) +static int ssl_parse_session_ticket_ext( ssl_context *ssl, + const unsigned char *buf, + size_t len ) +{ + if( ssl->session_tickets == SSL_SESSION_TICKETS_DISABLED || + len != 0 ) + { + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); + } + + ((void) buf); + + ssl->handshake->new_session_ticket = 1; + + return( 0 ); +} +#endif /* POLARSSL_SSL_SESSION_TICKETS */ + +#if defined(POLARSSL_ECDH_C) || defined(POLARSSL_ECDSA_C) +static int ssl_parse_supported_point_formats_ext( ssl_context *ssl, + const unsigned char *buf, + size_t len ) +{ + size_t list_size; + const unsigned char *p; + + list_size = buf[0]; + if( list_size + 1 != len ) + { + SSL_DEBUG_MSG( 1, ( "bad server hello message" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); + } + + p = buf + 1; + while( list_size > 0 ) + { + if( p[0] == POLARSSL_ECP_PF_UNCOMPRESSED || + p[0] == POLARSSL_ECP_PF_COMPRESSED ) + { + ssl->handshake->ecdh_ctx.point_format = p[0]; + SSL_DEBUG_MSG( 4, ( "point format selected: %d", p[0] ) ); + return( 0 ); + } + + list_size--; + p++; + } + + SSL_DEBUG_MSG( 1, ( "no point format in common" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); +} +#endif /* POLARSSL_ECDH_C || POLARSSL_ECDSA_C */ + +#if defined(POLARSSL_SSL_ALPN) +static int ssl_parse_alpn_ext( ssl_context *ssl, + const unsigned char *buf, size_t len ) +{ + size_t list_len, name_len; + const char **p; + + /* If we didn't send it, the server shouldn't send it */ + if( ssl->alpn_list == NULL ) + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); + + /* + * opaque ProtocolName<1..2^8-1>; + * + * struct { + * ProtocolName protocol_name_list<2..2^16-1> + * } ProtocolNameList; + * + * the "ProtocolNameList" MUST contain exactly one "ProtocolName" + */ + + /* Min length is 2 (list_len) + 1 (name_len) + 1 (name) */ + if( len < 4 ) + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); + + list_len = ( buf[0] << 8 ) | buf[1]; + if( list_len != len - 2 ) + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); + + name_len = buf[2]; + if( name_len != list_len - 1 ) + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); + + /* Check that the server chosen protocol was in our list and save it */ + for( p = ssl->alpn_list; *p != NULL; p++ ) + { + if( name_len == strlen( *p ) && + memcmp( buf + 3, *p, name_len ) == 0 ) + { + ssl->alpn_chosen = *p; + return( 0 ); + } + } + + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); +} +#endif /* POLARSSL_SSL_ALPN */ + +static int ssl_parse_server_hello( ssl_context *ssl ) +{ + int ret, i, comp; + size_t n; + size_t ext_len; + unsigned char *buf, *ext; +#if defined(POLARSSL_SSL_RENEGOTIATION) + int renegotiation_info_seen = 0; +#endif + int handshake_failure = 0; + const ssl_ciphersuite_t *suite_info; +#if defined(POLARSSL_DEBUG_C) + uint32_t t; +#endif + + SSL_DEBUG_MSG( 2, ( "=> parse server hello" ) ); + + /* + * 0 . 0 handshake type + * 1 . 3 handshake length + * 4 . 5 protocol version + * 6 . 9 UNIX time() + * 10 . 37 random bytes + */ + buf = ssl->in_msg; + + if( ( ret = ssl_read_record( ssl ) ) != 0 ) + { + SSL_DEBUG_RET( 1, "ssl_read_record", ret ); + return( ret ); + } + + if( ssl->in_msgtype != SSL_MSG_HANDSHAKE ) + { +#if defined(POLARSSL_SSL_RENEGOTIATION) + if( ssl->renegotiation == SSL_RENEGOTIATION ) + { + ssl->renego_records_seen++; + + if( ssl->renego_max_records >= 0 && + ssl->renego_records_seen > ssl->renego_max_records ) + { + SSL_DEBUG_MSG( 1, ( "renegotiation requested, " + "but not honored by server" ) ); + return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE ); + } + + SSL_DEBUG_MSG( 1, ( "non-handshake message during renego" ) ); + return( POLARSSL_ERR_SSL_WAITING_SERVER_HELLO_RENEGO ); + } +#endif /* POLARSSL_SSL_RENEGOTIATION */ + + SSL_DEBUG_MSG( 1, ( "bad server hello message" ) ); + return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE ); + } + + SSL_DEBUG_MSG( 3, ( "server hello, chosen version: [%d:%d]", + buf[4], buf[5] ) ); + + if( ssl->in_hslen < 42 || + buf[0] != SSL_HS_SERVER_HELLO || + buf[4] != SSL_MAJOR_VERSION_3 ) + { + SSL_DEBUG_MSG( 1, ( "bad server hello message" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); + } + + if( buf[5] > ssl->max_minor_ver ) + { + SSL_DEBUG_MSG( 1, ( "bad server hello message" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); + } + + ssl->minor_ver = buf[5]; + + if( ssl->minor_ver < ssl->min_minor_ver ) + { + SSL_DEBUG_MSG( 1, ( "server only supports ssl smaller than minimum" + " [%d:%d] < [%d:%d]", ssl->major_ver, + ssl->minor_ver, buf[4], buf[5] ) ); + + ssl_send_alert_message( ssl, SSL_ALERT_LEVEL_FATAL, + SSL_ALERT_MSG_PROTOCOL_VERSION ); + + return( POLARSSL_ERR_SSL_BAD_HS_PROTOCOL_VERSION ); + } + +#if defined(POLARSSL_DEBUG_C) + t = ( (uint32_t) buf[6] << 24 ) + | ( (uint32_t) buf[7] << 16 ) + | ( (uint32_t) buf[8] << 8 ) + | ( (uint32_t) buf[9] ); + SSL_DEBUG_MSG( 3, ( "server hello, current time: %lu", t ) ); +#endif + + memcpy( ssl->handshake->randbytes + 32, buf + 6, 32 ); + + n = buf[38]; + + SSL_DEBUG_BUF( 3, "server hello, random bytes", buf + 6, 32 ); + + if( n > 32 ) + { + SSL_DEBUG_MSG( 1, ( "bad server hello message" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); + } + + /* + * 38 . 38 session id length + * 39 . 38+n session id + * 39+n . 40+n chosen ciphersuite + * 41+n . 41+n chosen compression alg. + * 42+n . 43+n extensions length + * 44+n . 44+n+m extensions + */ + if( ssl->in_hslen > 43 + n ) + { + ext_len = ( ( buf[42 + n] << 8 ) + | ( buf[43 + n] ) ); + + if( ( ext_len > 0 && ext_len < 4 ) || + ssl->in_hslen != 44 + n + ext_len ) + { + SSL_DEBUG_MSG( 1, ( "bad server hello message" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); + } + } + else if( ssl->in_hslen == 42 + n ) + { + ext_len = 0; + } + else + { + SSL_DEBUG_MSG( 1, ( "bad server hello message" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); + } + + i = ( buf[39 + n] << 8 ) | buf[40 + n]; + comp = buf[41 + n]; + + /* + * Initialize update checksum functions + */ + ssl->transform_negotiate->ciphersuite_info = ssl_ciphersuite_from_id( i ); + + if( ssl->transform_negotiate->ciphersuite_info == NULL ) + { + SSL_DEBUG_MSG( 1, ( "ciphersuite info for %04x not found", i ) ); + return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); + } + + ssl_optimize_checksum( ssl, ssl->transform_negotiate->ciphersuite_info ); + + SSL_DEBUG_MSG( 3, ( "server hello, session id len.: %d", n ) ); + SSL_DEBUG_BUF( 3, "server hello, session id", buf + 39, n ); + + /* + * Check if the session can be resumed + */ + if( ssl->handshake->resume == 0 || n == 0 || +#if defined(POLARSSL_SSL_RENEGOTIATION) + ssl->renegotiation != SSL_INITIAL_HANDSHAKE || +#endif + ssl->session_negotiate->ciphersuite != i || + ssl->session_negotiate->compression != comp || + ssl->session_negotiate->length != n || + memcmp( ssl->session_negotiate->id, buf + 39, n ) != 0 ) + { + ssl->state++; + ssl->handshake->resume = 0; +#if defined(POLARSSL_HAVE_TIME) + ssl->session_negotiate->start = time( NULL ); +#endif + ssl->session_negotiate->ciphersuite = i; + ssl->session_negotiate->compression = comp; + ssl->session_negotiate->length = n; + memcpy( ssl->session_negotiate->id, buf + 39, n ); + } + else + { + ssl->state = SSL_SERVER_CHANGE_CIPHER_SPEC; + + if( ( ret = ssl_derive_keys( ssl ) ) != 0 ) + { + SSL_DEBUG_RET( 1, "ssl_derive_keys", ret ); + return( ret ); + } + } + + SSL_DEBUG_MSG( 3, ( "%s session has been resumed", + ssl->handshake->resume ? "a" : "no" ) ); + + SSL_DEBUG_MSG( 3, ( "server hello, chosen ciphersuite: %d", i ) ); + SSL_DEBUG_MSG( 3, ( "server hello, compress alg.: %d", buf[41 + n] ) ); + + suite_info = ssl_ciphersuite_from_id( ssl->session_negotiate->ciphersuite ); + if( suite_info == NULL || + ( ssl->arc4_disabled && + suite_info->cipher == POLARSSL_CIPHER_ARC4_128 ) ) + { + SSL_DEBUG_MSG( 1, ( "bad server hello message" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); + } + + + i = 0; + while( 1 ) + { + if( ssl->ciphersuite_list[ssl->minor_ver][i] == 0 ) + { + SSL_DEBUG_MSG( 1, ( "bad server hello message" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); + } + + if( ssl->ciphersuite_list[ssl->minor_ver][i++] == + ssl->session_negotiate->ciphersuite ) + { + break; + } + } + + if( comp != SSL_COMPRESS_NULL +#if defined(POLARSSL_ZLIB_SUPPORT) + && comp != SSL_COMPRESS_DEFLATE +#endif + ) + { + SSL_DEBUG_MSG( 1, ( "bad server hello message" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); + } + ssl->session_negotiate->compression = comp; + + ext = buf + 44 + n; + + SSL_DEBUG_MSG( 2, ( "server hello, total extension length: %d", ext_len ) ); + + while( ext_len ) + { + unsigned int ext_id = ( ( ext[0] << 8 ) + | ( ext[1] ) ); + unsigned int ext_size = ( ( ext[2] << 8 ) + | ( ext[3] ) ); + + if( ext_size + 4 > ext_len ) + { + SSL_DEBUG_MSG( 1, ( "bad server hello message" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); + } + + switch( ext_id ) + { + case TLS_EXT_RENEGOTIATION_INFO: + SSL_DEBUG_MSG( 3, ( "found renegotiation extension" ) ); +#if defined(POLARSSL_SSL_RENEGOTIATION) + renegotiation_info_seen = 1; +#endif + + if( ( ret = ssl_parse_renegotiation_info( ssl, ext + 4, + ext_size ) ) != 0 ) + return( ret ); + + break; + +#if defined(POLARSSL_SSL_MAX_FRAGMENT_LENGTH) + case TLS_EXT_MAX_FRAGMENT_LENGTH: + SSL_DEBUG_MSG( 3, ( "found max_fragment_length extension" ) ); + + if( ( ret = ssl_parse_max_fragment_length_ext( ssl, + ext + 4, ext_size ) ) != 0 ) + { + return( ret ); + } + + break; +#endif /* POLARSSL_SSL_MAX_FRAGMENT_LENGTH */ + +#if defined(POLARSSL_SSL_TRUNCATED_HMAC) + case TLS_EXT_TRUNCATED_HMAC: + SSL_DEBUG_MSG( 3, ( "found truncated_hmac extension" ) ); + + if( ( ret = ssl_parse_truncated_hmac_ext( ssl, + ext + 4, ext_size ) ) != 0 ) + { + return( ret ); + } + + break; +#endif /* POLARSSL_SSL_TRUNCATED_HMAC */ + +#if defined(POLARSSL_SSL_ENCRYPT_THEN_MAC) + case TLS_EXT_ENCRYPT_THEN_MAC: + SSL_DEBUG_MSG( 3, ( "found encrypt_then_mac extension" ) ); + + if( ( ret = ssl_parse_encrypt_then_mac_ext( ssl, + ext + 4, ext_size ) ) != 0 ) + { + return( ret ); + } + + break; +#endif /* POLARSSL_SSL_ENCRYPT_THEN_MAC */ + +#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET) + case TLS_EXT_EXTENDED_MASTER_SECRET: + SSL_DEBUG_MSG( 3, ( "found extended_master_secret extension" ) ); + + if( ( ret = ssl_parse_extended_ms_ext( ssl, + ext + 4, ext_size ) ) != 0 ) + { + return( ret ); + } + + break; +#endif /* POLARSSL_SSL_EXTENDED_MASTER_SECRET */ + +#if defined(POLARSSL_SSL_SESSION_TICKETS) + case TLS_EXT_SESSION_TICKET: + SSL_DEBUG_MSG( 3, ( "found session_ticket extension" ) ); + + if( ( ret = ssl_parse_session_ticket_ext( ssl, + ext + 4, ext_size ) ) != 0 ) + { + return( ret ); + } + + break; +#endif /* POLARSSL_SSL_SESSION_TICKETS */ + +#if defined(POLARSSL_ECDH_C) || defined(POLARSSL_ECDSA_C) + case TLS_EXT_SUPPORTED_POINT_FORMATS: + SSL_DEBUG_MSG( 3, ( "found supported_point_formats extension" ) ); + + if( ( ret = ssl_parse_supported_point_formats_ext( ssl, + ext + 4, ext_size ) ) != 0 ) + { + return( ret ); + } + + break; +#endif /* POLARSSL_ECDH_C || POLARSSL_ECDSA_C */ + +#if defined(POLARSSL_SSL_ALPN) + case TLS_EXT_ALPN: + SSL_DEBUG_MSG( 3, ( "found alpn extension" ) ); + + if( ( ret = ssl_parse_alpn_ext( ssl, ext + 4, ext_size ) ) != 0 ) + return( ret ); + + break; +#endif /* POLARSSL_SSL_ALPN */ + + default: + SSL_DEBUG_MSG( 3, ( "unknown extension found: %d (ignoring)", + ext_id ) ); + } + + ext_len -= 4 + ext_size; + ext += 4 + ext_size; + + if( ext_len > 0 && ext_len < 4 ) + { + SSL_DEBUG_MSG( 1, ( "bad server hello message" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); + } + } + + /* + * Renegotiation security checks + */ + if( ssl->secure_renegotiation == SSL_LEGACY_RENEGOTIATION && + ssl->allow_legacy_renegotiation == SSL_LEGACY_BREAK_HANDSHAKE ) + { + SSL_DEBUG_MSG( 1, ( "legacy renegotiation, breaking off handshake" ) ); + handshake_failure = 1; + } +#if defined(POLARSSL_SSL_RENEGOTIATION) + else if( ssl->renegotiation == SSL_RENEGOTIATION && + ssl->secure_renegotiation == SSL_SECURE_RENEGOTIATION && + renegotiation_info_seen == 0 ) + { + SSL_DEBUG_MSG( 1, ( "renegotiation_info extension missing (secure)" ) ); + handshake_failure = 1; + } + else if( ssl->renegotiation == SSL_RENEGOTIATION && + ssl->secure_renegotiation == SSL_LEGACY_RENEGOTIATION && + ssl->allow_legacy_renegotiation == SSL_LEGACY_NO_RENEGOTIATION ) + { + SSL_DEBUG_MSG( 1, ( "legacy renegotiation not allowed" ) ); + handshake_failure = 1; + } + else if( ssl->renegotiation == SSL_RENEGOTIATION && + ssl->secure_renegotiation == SSL_LEGACY_RENEGOTIATION && + renegotiation_info_seen == 1 ) + { + SSL_DEBUG_MSG( 1, ( "renegotiation_info extension present (legacy)" ) ); + handshake_failure = 1; + } +#endif /* POLARSSL_SSL_RENEGOTIATION */ + + if( handshake_failure == 1 ) + { + if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 ) + return( ret ); + + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); + } + + SSL_DEBUG_MSG( 2, ( "<= parse server hello" ) ); + + return( 0 ); +} + +#if defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED) +static int ssl_parse_server_dh_params( ssl_context *ssl, unsigned char **p, + unsigned char *end ) +{ + int ret = POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE; + + /* + * Ephemeral DH parameters: + * + * struct { + * opaque dh_p<1..2^16-1>; + * opaque dh_g<1..2^16-1>; + * opaque dh_Ys<1..2^16-1>; + * } ServerDHParams; + */ + if( ( ret = dhm_read_params( &ssl->handshake->dhm_ctx, p, end ) ) != 0 ) + { + SSL_DEBUG_RET( 2, ( "dhm_read_params" ), ret ); + return( ret ); + } + + if( ssl->handshake->dhm_ctx.len < SSL_MIN_DHM_BYTES || + ssl->handshake->dhm_ctx.len > 512 ) + { + SSL_DEBUG_MSG( 1, ( "bad server key exchange message (DHM length)" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE ); + } + + SSL_DEBUG_MPI( 3, "DHM: P ", &ssl->handshake->dhm_ctx.P ); + SSL_DEBUG_MPI( 3, "DHM: G ", &ssl->handshake->dhm_ctx.G ); + SSL_DEBUG_MPI( 3, "DHM: GY", &ssl->handshake->dhm_ctx.GY ); + + return( ret ); +} +#endif /* POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED || + POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED */ + +#if defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED) +static int ssl_check_server_ecdh_params( const ssl_context *ssl ) +{ + const ecp_curve_info *curve_info; + + curve_info = ecp_curve_info_from_grp_id( ssl->handshake->ecdh_ctx.grp.id ); + if( curve_info == NULL ) + { + SSL_DEBUG_MSG( 1, ( "should never happen" ) ); + return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); + } + + SSL_DEBUG_MSG( 2, ( "ECDH curve: %s", curve_info->name ) ); + +#if defined(POLARSSL_SSL_SET_CURVES) + if( ! ssl_curve_is_acceptable( ssl, ssl->handshake->ecdh_ctx.grp.id ) ) +#else + if( ssl->handshake->ecdh_ctx.grp.nbits < 163 || + ssl->handshake->ecdh_ctx.grp.nbits > 521 ) +#endif + return( -1 ); + + SSL_DEBUG_ECP( 3, "ECDH: Qp", &ssl->handshake->ecdh_ctx.Qp ); + + return( 0 ); +} +#endif /* POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED || + POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED || + POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED || + POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED || + POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */ + +#if defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED) +static int ssl_parse_server_ecdh_params( ssl_context *ssl, + unsigned char **p, + unsigned char *end ) +{ + int ret = POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE; + + /* + * Ephemeral ECDH parameters: + * + * struct { + * ECParameters curve_params; + * ECPoint public; + * } ServerECDHParams; + */ + if( ( ret = ecdh_read_params( &ssl->handshake->ecdh_ctx, + (const unsigned char **) p, end ) ) != 0 ) + { + SSL_DEBUG_RET( 1, ( "ecdh_read_params" ), ret ); + return( ret ); + } + + if( ssl_check_server_ecdh_params( ssl ) != 0 ) + { + SSL_DEBUG_MSG( 1, ( "bad server key exchange message (ECDHE curve)" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE ); + } + + return( ret ); +} +#endif /* POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED || + POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED || + POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED */ + +#if defined(POLARSSL_KEY_EXCHANGE__SOME__PSK_ENABLED) +static int ssl_parse_server_psk_hint( ssl_context *ssl, + unsigned char **p, + unsigned char *end ) +{ + int ret = POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE; + size_t len; + ((void) ssl); + + /* + * PSK parameters: + * + * opaque psk_identity_hint<0..2^16-1>; + */ + len = (*p)[0] << 8 | (*p)[1]; + *p += 2; + + if( (*p) + len > end ) + { + SSL_DEBUG_MSG( 1, ( "bad server key exchange message (psk_identity_hint length)" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE ); + } + + // TODO: Retrieve PSK identity hint and callback to app + // + *p += len; + ret = 0; + + return( ret ); +} +#endif /* POLARSSL_KEY_EXCHANGE__SOME__PSK_ENABLED */ + +#if defined(POLARSSL_KEY_EXCHANGE_RSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_RSA_PSK_ENABLED) +/* + * Generate a pre-master secret and encrypt it with the server's RSA key + */ +static int ssl_write_encrypted_pms( ssl_context *ssl, + size_t offset, size_t *olen, + size_t pms_offset ) +{ + int ret; + size_t len_bytes = ssl->minor_ver == SSL_MINOR_VERSION_0 ? 0 : 2; + unsigned char *p = ssl->handshake->premaster + pms_offset; + + if( offset + len_bytes > SSL_MAX_CONTENT_LEN ) + { + SSL_DEBUG_MSG( 1, ( "buffer too small for encrypted pms" ) ); + return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); + } + + /* + * Generate (part of) the pre-master as + * struct { + * ProtocolVersion client_version; + * opaque random[46]; + * } PreMasterSecret; + */ + p[0] = (unsigned char) ssl->max_major_ver; + p[1] = (unsigned char) ssl->max_minor_ver; + + if( ( ret = ssl->f_rng( ssl->p_rng, p + 2, 46 ) ) != 0 ) + { + SSL_DEBUG_RET( 1, "f_rng", ret ); + return( ret ); + } + + ssl->handshake->pmslen = 48; + + /* + * Now write it out, encrypted + */ + if( ! pk_can_do( &ssl->session_negotiate->peer_cert->pk, + POLARSSL_PK_RSA ) ) + { + SSL_DEBUG_MSG( 1, ( "certificate key type mismatch" ) ); + return( POLARSSL_ERR_SSL_PK_TYPE_MISMATCH ); + } + + if( ( ret = pk_encrypt( &ssl->session_negotiate->peer_cert->pk, + p, ssl->handshake->pmslen, + ssl->out_msg + offset + len_bytes, olen, + SSL_MAX_CONTENT_LEN - offset - len_bytes, + ssl->f_rng, ssl->p_rng ) ) != 0 ) + { + SSL_DEBUG_RET( 1, "rsa_pkcs1_encrypt", ret ); + return( ret ); + } + +#if defined(POLARSSL_SSL_PROTO_TLS1) || defined(POLARSSL_SSL_PROTO_TLS1_1) || \ + defined(POLARSSL_SSL_PROTO_TLS1_2) + if( len_bytes == 2 ) + { + ssl->out_msg[offset+0] = (unsigned char)( *olen >> 8 ); + ssl->out_msg[offset+1] = (unsigned char)( *olen ); + *olen += 2; + } +#endif + + return( 0 ); +} +#endif /* POLARSSL_KEY_EXCHANGE_RSA_ENABLED || + POLARSSL_KEY_EXCHANGE_RSA_PSK_ENABLED */ + +#if defined(POLARSSL_SSL_PROTO_TLS1_2) +#if defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) +static int ssl_parse_signature_algorithm( ssl_context *ssl, + unsigned char **p, + unsigned char *end, + md_type_t *md_alg, + pk_type_t *pk_alg ) +{ + ((void) ssl); + *md_alg = POLARSSL_MD_NONE; + *pk_alg = POLARSSL_PK_NONE; + + /* Only in TLS 1.2 */ + if( ssl->minor_ver != SSL_MINOR_VERSION_3 ) + { + return( 0 ); + } + + if( (*p) + 2 > end ) + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE ); + + /* + * Get hash algorithm + */ + if( ( *md_alg = ssl_md_alg_from_hash( (*p)[0] ) ) == POLARSSL_MD_NONE ) + { + SSL_DEBUG_MSG( 2, ( "Server used unsupported " + "HashAlgorithm %d", *(p)[0] ) ); + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE ); + } + + /* + * Get signature algorithm + */ + if( ( *pk_alg = ssl_pk_alg_from_sig( (*p)[1] ) ) == POLARSSL_PK_NONE ) + { + SSL_DEBUG_MSG( 2, ( "server used unsupported " + "SignatureAlgorithm %d", (*p)[1] ) ); + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE ); + } + + SSL_DEBUG_MSG( 2, ( "Server used SignatureAlgorithm %d", (*p)[1] ) ); + SSL_DEBUG_MSG( 2, ( "Server used HashAlgorithm %d", (*p)[0] ) ); + *p += 2; + + return( 0 ); +} +#endif /* POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED || + POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED || + POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */ +#endif /* POLARSSL_SSL_PROTO_TLS1_2 */ + + +#if defined(POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED) +static int ssl_get_ecdh_params_from_cert( ssl_context *ssl ) +{ + int ret; + const ecp_keypair *peer_key; + + if( ! pk_can_do( &ssl->session_negotiate->peer_cert->pk, + POLARSSL_PK_ECKEY ) ) + { + SSL_DEBUG_MSG( 1, ( "server key not ECDH capable" ) ); + return( POLARSSL_ERR_SSL_PK_TYPE_MISMATCH ); + } + + peer_key = pk_ec( ssl->session_negotiate->peer_cert->pk ); + + if( ( ret = ecdh_get_params( &ssl->handshake->ecdh_ctx, peer_key, + POLARSSL_ECDH_THEIRS ) ) != 0 ) + { + SSL_DEBUG_RET( 1, ( "ecdh_get_params" ), ret ); + return( ret ); + } + + if( ssl_check_server_ecdh_params( ssl ) != 0 ) + { + SSL_DEBUG_MSG( 1, ( "bad server certificate (ECDH curve)" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE ); + } + + return( ret ); +} +#endif /* POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED) || + POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */ + +static int ssl_parse_server_key_exchange( ssl_context *ssl ) +{ + int ret; + const ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info; + unsigned char *p, *end; +#if defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) + size_t sig_len, params_len; + unsigned char hash[64]; + md_type_t md_alg = POLARSSL_MD_NONE; + size_t hashlen; + pk_type_t pk_alg = POLARSSL_PK_NONE; +#endif + + SSL_DEBUG_MSG( 2, ( "=> parse server key exchange" ) ); + +#if defined(POLARSSL_KEY_EXCHANGE_RSA_ENABLED) + if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA ) + { + SSL_DEBUG_MSG( 2, ( "<= skip parse server key exchange" ) ); + ssl->state++; + return( 0 ); + } + ((void) p); + ((void) end); +#endif + +#if defined(POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED) + if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDH_RSA || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDH_ECDSA ) + { + if( ( ret = ssl_get_ecdh_params_from_cert( ssl ) ) != 0 ) + { + SSL_DEBUG_RET( 1, "ssl_get_ecdh_params_from_cert", ret ); + return( ret ); + } + + SSL_DEBUG_MSG( 2, ( "<= skip parse server key exchange" ) ); + ssl->state++; + return( 0 ); + } + ((void) p); + ((void) end); +#endif /* POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED || + POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */ + + if( ( ret = ssl_read_record( ssl ) ) != 0 ) + { + SSL_DEBUG_RET( 1, "ssl_read_record", ret ); + return( ret ); + } + + if( ssl->in_msgtype != SSL_MSG_HANDSHAKE ) + { + SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) ); + return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE ); + } + + /* + * ServerKeyExchange may be skipped with PSK and RSA-PSK when the server + * doesn't use a psk_identity_hint + */ + if( ssl->in_msg[0] != SSL_HS_SERVER_KEY_EXCHANGE ) + { + if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK ) + { + ssl->record_read = 1; + goto exit; + } + + SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) ); + return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE ); + } + + p = ssl->in_msg + 4; + end = ssl->in_msg + ssl->in_hslen; + SSL_DEBUG_BUF( 3, "server key exchange", p, ssl->in_hslen - 4 ); + +#if defined(POLARSSL_KEY_EXCHANGE__SOME__PSK_ENABLED) + if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK ) + { + if( ssl_parse_server_psk_hint( ssl, &p, end ) != 0 ) + { + SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE ); + } + } /* FALLTROUGH */ +#endif /* POLARSSL_KEY_EXCHANGE__SOME__PSK_ENABLED */ + +#if defined(POLARSSL_KEY_EXCHANGE_PSK_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_RSA_PSK_ENABLED) + if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK ) + ; /* nothing more to do */ + else +#endif /* POLARSSL_KEY_EXCHANGE_PSK_ENABLED || + POLARSSL_KEY_EXCHANGE_RSA_PSK_ENABLED */ +#if defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED) + if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_RSA || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK ) + { + if( ssl_parse_server_dh_params( ssl, &p, end ) != 0 ) + { + SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE ); + } + } + else +#endif /* POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED || + POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED */ +#if defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) + if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_RSA || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA ) + { + if( ssl_parse_server_ecdh_params( ssl, &p, end ) != 0 ) + { + SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE ); + } + } + else +#endif /* POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED || + POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED || + POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */ + { + SSL_DEBUG_MSG( 1, ( "should never happen" ) ); + return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); + } + +#if defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) + if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_RSA || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_RSA || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA ) + { + params_len = p - ( ssl->in_msg + 4 ); + + /* + * Handle the digitally-signed structure + */ +#if defined(POLARSSL_SSL_PROTO_TLS1_2) + if( ssl->minor_ver == SSL_MINOR_VERSION_3 ) + { + if( ssl_parse_signature_algorithm( ssl, &p, end, + &md_alg, &pk_alg ) != 0 ) + { + SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE ); + } + + if( pk_alg != ssl_get_ciphersuite_sig_pk_alg( ciphersuite_info ) ) + { + SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE ); + } + } + else +#endif /* POLARSSL_SSL_PROTO_TLS1_2 */ +#if defined(POLARSSL_SSL_PROTO_SSL3) || defined(POLARSSL_SSL_PROTO_TLS1) || \ + defined(POLARSSL_SSL_PROTO_TLS1_1) + if( ssl->minor_ver < SSL_MINOR_VERSION_3 ) + { + pk_alg = ssl_get_ciphersuite_sig_pk_alg( ciphersuite_info ); + + /* Default hash for ECDSA is SHA-1 */ + if( pk_alg == POLARSSL_PK_ECDSA && md_alg == POLARSSL_MD_NONE ) + md_alg = POLARSSL_MD_SHA1; + } + else +#endif + { + SSL_DEBUG_MSG( 1, ( "should never happen" ) ); + return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); + } + + /* + * Read signature + */ + sig_len = ( p[0] << 8 ) | p[1]; + p += 2; + + if( end != p + sig_len ) + { + SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE ); + } + + SSL_DEBUG_BUF( 3, "signature", p, sig_len ); + + /* + * Compute the hash that has been signed + */ +#if defined(POLARSSL_SSL_PROTO_SSL3) || defined(POLARSSL_SSL_PROTO_TLS1) || \ + defined(POLARSSL_SSL_PROTO_TLS1_1) + if( md_alg == POLARSSL_MD_NONE ) + { + md5_context md5; + sha1_context sha1; + + md5_init( &md5 ); + sha1_init( &sha1 ); + + hashlen = 36; + + /* + * digitally-signed struct { + * opaque md5_hash[16]; + * opaque sha_hash[20]; + * }; + * + * md5_hash + * MD5(ClientHello.random + ServerHello.random + * + ServerParams); + * sha_hash + * SHA(ClientHello.random + ServerHello.random + * + ServerParams); + */ + md5_starts( &md5 ); + md5_update( &md5, ssl->handshake->randbytes, 64 ); + md5_update( &md5, ssl->in_msg + 4, params_len ); + md5_finish( &md5, hash ); + + sha1_starts( &sha1 ); + sha1_update( &sha1, ssl->handshake->randbytes, 64 ); + sha1_update( &sha1, ssl->in_msg + 4, params_len ); + sha1_finish( &sha1, hash + 16 ); + + md5_free( &md5 ); + sha1_free( &sha1 ); + } + else +#endif /* POLARSSL_SSL_PROTO_SSL3 || POLARSSL_SSL_PROTO_TLS1 || \ + POLARSSL_SSL_PROTO_TLS1_1 */ +#if defined(POLARSSL_SSL_PROTO_TLS1) || defined(POLARSSL_SSL_PROTO_TLS1_1) || \ + defined(POLARSSL_SSL_PROTO_TLS1_2) + if( md_alg != POLARSSL_MD_NONE ) + { + md_context_t ctx; + + md_init( &ctx ); + + /* Info from md_alg will be used instead */ + hashlen = 0; + + /* + * digitally-signed struct { + * opaque client_random[32]; + * opaque server_random[32]; + * ServerDHParams params; + * }; + */ + if( ( ret = md_init_ctx( &ctx, + md_info_from_type( md_alg ) ) ) != 0 ) + { + SSL_DEBUG_RET( 1, "md_init_ctx", ret ); + return( ret ); + } + + md_starts( &ctx ); + md_update( &ctx, ssl->handshake->randbytes, 64 ); + md_update( &ctx, ssl->in_msg + 4, params_len ); + md_finish( &ctx, hash ); + md_free( &ctx ); + } + else +#endif /* POLARSSL_SSL_PROTO_TLS1 || POLARSSL_SSL_PROTO_TLS1_1 || \ + POLARSSL_SSL_PROTO_TLS1_2 */ + { + SSL_DEBUG_MSG( 1, ( "should never happen" ) ); + return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); + } + + SSL_DEBUG_BUF( 3, "parameters hash", hash, hashlen != 0 ? hashlen : + (unsigned int) ( md_info_from_type( md_alg ) )->size ); + + /* + * Verify signature + */ + if( ! pk_can_do( &ssl->session_negotiate->peer_cert->pk, pk_alg ) ) + { + SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) ); + return( POLARSSL_ERR_SSL_PK_TYPE_MISMATCH ); + } + + if( ( ret = pk_verify( &ssl->session_negotiate->peer_cert->pk, + md_alg, hash, hashlen, p, sig_len ) ) != 0 ) + { + SSL_DEBUG_RET( 1, "pk_verify", ret ); + return( ret ); + } + } +#endif /* POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED || + POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED || + POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */ + +exit: + ssl->state++; + + SSL_DEBUG_MSG( 2, ( "<= parse server key exchange" ) ); + + return( 0 ); +} + +#if !defined(POLARSSL_KEY_EXCHANGE_RSA_ENABLED) && \ + !defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED) && \ + !defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) && \ + !defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) +static int ssl_parse_certificate_request( ssl_context *ssl ) +{ + const ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info; + + SSL_DEBUG_MSG( 2, ( "=> parse certificate request" ) ); + + if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK ) + { + SSL_DEBUG_MSG( 2, ( "<= skip parse certificate request" ) ); + ssl->state++; + return( 0 ); + } + + SSL_DEBUG_MSG( 1, ( "should never happen" ) ); + return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); +} +#else +static int ssl_parse_certificate_request( ssl_context *ssl ) +{ + int ret; + unsigned char *buf, *p; + size_t n = 0, m = 0; + size_t cert_type_len = 0, dn_len = 0; + const ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info; + + SSL_DEBUG_MSG( 2, ( "=> parse certificate request" ) ); + + if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK ) + { + SSL_DEBUG_MSG( 2, ( "<= skip parse certificate request" ) ); + ssl->state++; + return( 0 ); + } + + /* + * 0 . 0 handshake type + * 1 . 3 handshake length + * 4 . 4 cert type count + * 5 .. m-1 cert types + * m .. m+1 sig alg length (TLS 1.2 only) + * m+1 .. n-1 SignatureAndHashAlgorithms (TLS 1.2 only) + * n .. n+1 length of all DNs + * n+2 .. n+3 length of DN 1 + * n+4 .. ... Distinguished Name #1 + * ... .. ... length of DN 2, etc. + */ + if( ssl->record_read == 0 ) + { + if( ( ret = ssl_read_record( ssl ) ) != 0 ) + { + SSL_DEBUG_RET( 1, "ssl_read_record", ret ); + return( ret ); + } + + if( ssl->in_msgtype != SSL_MSG_HANDSHAKE ) + { + SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) ); + return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE ); + } + + ssl->record_read = 1; + } + + ssl->client_auth = 0; + ssl->state++; + + if( ssl->in_msg[0] == SSL_HS_CERTIFICATE_REQUEST ) + ssl->client_auth++; + + SSL_DEBUG_MSG( 3, ( "got %s certificate request", + ssl->client_auth ? "a" : "no" ) ); + + if( ssl->client_auth == 0 ) + goto exit; + + ssl->record_read = 0; + + // TODO: handshake_failure alert for an anonymous server to request + // client authentication + + buf = ssl->in_msg; + + // Retrieve cert types + // + cert_type_len = buf[4]; + n = cert_type_len; + + if( ssl->in_hslen < 6 + n ) + { + SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST ); + } + + p = buf + 5; + while( cert_type_len > 0 ) + { +#if defined(POLARSSL_RSA_C) + if( *p == SSL_CERT_TYPE_RSA_SIGN && + pk_can_do( ssl_own_key( ssl ), POLARSSL_PK_RSA ) ) + { + ssl->handshake->cert_type = SSL_CERT_TYPE_RSA_SIGN; + break; + } + else +#endif +#if defined(POLARSSL_ECDSA_C) + if( *p == SSL_CERT_TYPE_ECDSA_SIGN && + pk_can_do( ssl_own_key( ssl ), POLARSSL_PK_ECDSA ) ) + { + ssl->handshake->cert_type = SSL_CERT_TYPE_ECDSA_SIGN; + break; + } + else +#endif + { + ; /* Unsupported cert type, ignore */ + } + + cert_type_len--; + p++; + } + +#if defined(POLARSSL_SSL_PROTO_TLS1_2) + if( ssl->minor_ver == SSL_MINOR_VERSION_3 ) + { + /* Ignored, see comments about hash in write_certificate_verify */ + // TODO: should check the signature part against our pk_key though + size_t sig_alg_len = ( ( buf[5 + n] << 8 ) + | ( buf[6 + n] ) ); + + p = buf + 7 + n; + m += 2; + n += sig_alg_len; + + if( ssl->in_hslen < 6 + n ) + { + SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST ); + } + } +#endif /* POLARSSL_SSL_PROTO_TLS1_2 */ + + /* Ignore certificate_authorities, we only have one cert anyway */ + // TODO: should not send cert if no CA matches + dn_len = ( ( buf[5 + m + n] << 8 ) + | ( buf[6 + m + n] ) ); + + n += dn_len; + if( ssl->in_hslen != 7 + m + n ) + { + SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST ); + } + +exit: + SSL_DEBUG_MSG( 2, ( "<= parse certificate request" ) ); + + return( 0 ); +} +#endif /* !POLARSSL_KEY_EXCHANGE_RSA_ENABLED && + !POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED && + !POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED && + !POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */ + +static int ssl_parse_server_hello_done( ssl_context *ssl ) +{ + int ret; + + SSL_DEBUG_MSG( 2, ( "=> parse server hello done" ) ); + + if( ssl->record_read == 0 ) + { + if( ( ret = ssl_read_record( ssl ) ) != 0 ) + { + SSL_DEBUG_RET( 1, "ssl_read_record", ret ); + return( ret ); + } + + if( ssl->in_msgtype != SSL_MSG_HANDSHAKE ) + { + SSL_DEBUG_MSG( 1, ( "bad server hello done message" ) ); + return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE ); + } + } + ssl->record_read = 0; + + if( ssl->in_hslen != 4 || + ssl->in_msg[0] != SSL_HS_SERVER_HELLO_DONE ) + { + SSL_DEBUG_MSG( 1, ( "bad server hello done message" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO_DONE ); + } + + ssl->state++; + + SSL_DEBUG_MSG( 2, ( "<= parse server hello done" ) ); + + return( 0 ); +} + +static int ssl_write_client_key_exchange( ssl_context *ssl ) +{ + int ret; + size_t i, n; + const ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info; + + SSL_DEBUG_MSG( 2, ( "=> write client key exchange" ) ); + +#if defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED) + if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_RSA ) + { + /* + * DHM key exchange -- send G^X mod P + */ + n = ssl->handshake->dhm_ctx.len; + + ssl->out_msg[4] = (unsigned char)( n >> 8 ); + ssl->out_msg[5] = (unsigned char)( n ); + i = 6; + + ret = dhm_make_public( &ssl->handshake->dhm_ctx, + (int) mpi_size( &ssl->handshake->dhm_ctx.P ), + &ssl->out_msg[i], n, + ssl->f_rng, ssl->p_rng ); + if( ret != 0 ) + { + SSL_DEBUG_RET( 1, "dhm_make_public", ret ); + return( ret ); + } + + SSL_DEBUG_MPI( 3, "DHM: X ", &ssl->handshake->dhm_ctx.X ); + SSL_DEBUG_MPI( 3, "DHM: GX", &ssl->handshake->dhm_ctx.GX ); + + ssl->handshake->pmslen = POLARSSL_PREMASTER_SIZE; + + if( ( ret = dhm_calc_secret( &ssl->handshake->dhm_ctx, + ssl->handshake->premaster, + &ssl->handshake->pmslen, + ssl->f_rng, ssl->p_rng ) ) != 0 ) + { + SSL_DEBUG_RET( 1, "dhm_calc_secret", ret ); + return( ret ); + } + + SSL_DEBUG_MPI( 3, "DHM: K ", &ssl->handshake->dhm_ctx.K ); + } + else +#endif /* POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED */ +#if defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED) + if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_RSA || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDH_RSA || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDH_ECDSA ) + { + /* + * ECDH key exchange -- send client public value + */ + i = 4; + + ret = ecdh_make_public( &ssl->handshake->ecdh_ctx, + &n, + &ssl->out_msg[i], 1000, + ssl->f_rng, ssl->p_rng ); + if( ret != 0 ) + { + SSL_DEBUG_RET( 1, "ecdh_make_public", ret ); + return( ret ); + } + + SSL_DEBUG_ECP( 3, "ECDH: Q", &ssl->handshake->ecdh_ctx.Q ); + + if( ( ret = ecdh_calc_secret( &ssl->handshake->ecdh_ctx, + &ssl->handshake->pmslen, + ssl->handshake->premaster, + POLARSSL_MPI_MAX_SIZE, + ssl->f_rng, ssl->p_rng ) ) != 0 ) + { + SSL_DEBUG_RET( 1, "ecdh_calc_secret", ret ); + return( ret ); + } + + SSL_DEBUG_MPI( 3, "ECDH: z", &ssl->handshake->ecdh_ctx.z ); + } + else +#endif /* POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED || + POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED || + POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED || + POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */ +#if defined(POLARSSL_KEY_EXCHANGE__SOME__PSK_ENABLED) + if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK ) + { + /* + * opaque psk_identity<0..2^16-1>; + */ + if( ssl->psk == NULL || ssl->psk_identity == NULL ) + return( POLARSSL_ERR_SSL_PRIVATE_KEY_REQUIRED ); + + i = 4; + n = ssl->psk_identity_len; + + if( i + 2 + n > SSL_MAX_CONTENT_LEN ) + { + SSL_DEBUG_MSG( 1, ( "psk identity too long or " + "SSL buffer too short" ) ); + return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); + } + + ssl->out_msg[i++] = (unsigned char)( n >> 8 ); + ssl->out_msg[i++] = (unsigned char)( n ); + + memcpy( ssl->out_msg + i, ssl->psk_identity, ssl->psk_identity_len ); + i += ssl->psk_identity_len; + +#if defined(POLARSSL_KEY_EXCHANGE_PSK_ENABLED) + if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK ) + { + n = 0; + } + else +#endif +#if defined(POLARSSL_KEY_EXCHANGE_RSA_PSK_ENABLED) + if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK ) + { + if( ( ret = ssl_write_encrypted_pms( ssl, i, &n, 2 ) ) != 0 ) + return( ret ); + } + else +#endif +#if defined(POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED) + if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK ) + { + /* + * ClientDiffieHellmanPublic public (DHM send G^X mod P) + */ + n = ssl->handshake->dhm_ctx.len; + + if( i + 2 + n > SSL_MAX_CONTENT_LEN ) + { + SSL_DEBUG_MSG( 1, ( "psk identity or DHM size too long" + " or SSL buffer too short" ) ); + return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); + } + + ssl->out_msg[i++] = (unsigned char)( n >> 8 ); + ssl->out_msg[i++] = (unsigned char)( n ); + + ret = dhm_make_public( &ssl->handshake->dhm_ctx, + (int) mpi_size( &ssl->handshake->dhm_ctx.P ), + &ssl->out_msg[i], n, + ssl->f_rng, ssl->p_rng ); + if( ret != 0 ) + { + SSL_DEBUG_RET( 1, "dhm_make_public", ret ); + return( ret ); + } + } + else +#endif /* POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED */ +#if defined(POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED) + if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK ) + { + /* + * ClientECDiffieHellmanPublic public; + */ + ret = ecdh_make_public( &ssl->handshake->ecdh_ctx, &n, + &ssl->out_msg[i], SSL_MAX_CONTENT_LEN - i, + ssl->f_rng, ssl->p_rng ); + if( ret != 0 ) + { + SSL_DEBUG_RET( 1, "ecdh_make_public", ret ); + return( ret ); + } + + SSL_DEBUG_ECP( 3, "ECDH: Q", &ssl->handshake->ecdh_ctx.Q ); + } + else +#endif /* POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED */ + { + SSL_DEBUG_MSG( 1, ( "should never happen" ) ); + return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); + } + + if( ( ret = ssl_psk_derive_premaster( ssl, + ciphersuite_info->key_exchange ) ) != 0 ) + { + SSL_DEBUG_RET( 1, "ssl_psk_derive_premaster", ret ); + return( ret ); + } + } + else +#endif /* POLARSSL_KEY_EXCHANGE__SOME__PSK_ENABLED */ +#if defined(POLARSSL_KEY_EXCHANGE_RSA_ENABLED) + if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA ) + { + i = 4; + if( ( ret = ssl_write_encrypted_pms( ssl, i, &n, 0 ) ) != 0 ) + return( ret ); + } + else +#endif /* POLARSSL_KEY_EXCHANGE_RSA_ENABLED */ + { + ((void) ciphersuite_info); + SSL_DEBUG_MSG( 1, ( "should never happen" ) ); + return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); + } + + ssl->out_msglen = i + n; + ssl->out_msgtype = SSL_MSG_HANDSHAKE; + ssl->out_msg[0] = SSL_HS_CLIENT_KEY_EXCHANGE; + + ssl->state++; + + if( ( ret = ssl_write_record( ssl ) ) != 0 ) + { + SSL_DEBUG_RET( 1, "ssl_write_record", ret ); + return( ret ); + } + + SSL_DEBUG_MSG( 2, ( "<= write client key exchange" ) ); + + return( 0 ); +} + +#if !defined(POLARSSL_KEY_EXCHANGE_RSA_ENABLED) && \ + !defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED) && \ + !defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) && \ + !defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) +static int ssl_write_certificate_verify( ssl_context *ssl ) +{ + const ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info; + int ret; + + SSL_DEBUG_MSG( 2, ( "=> write certificate verify" ) ); + + if( ( ret = ssl_derive_keys( ssl ) ) != 0 ) + { + SSL_DEBUG_RET( 1, "ssl_derive_keys", ret ); + return( ret ); + } + + if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK ) + { + SSL_DEBUG_MSG( 2, ( "<= skip write certificate verify" ) ); + ssl->state++; + return( 0 ); + } + + SSL_DEBUG_MSG( 1, ( "should never happen" ) ); + return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); +} +#else +static int ssl_write_certificate_verify( ssl_context *ssl ) +{ + int ret = POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE; + const ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info; + size_t n = 0, offset = 0; + unsigned char hash[48]; + unsigned char *hash_start = hash; + md_type_t md_alg = POLARSSL_MD_NONE; + unsigned int hashlen; + + SSL_DEBUG_MSG( 2, ( "=> write certificate verify" ) ); + + if( ( ret = ssl_derive_keys( ssl ) ) != 0 ) + { + SSL_DEBUG_RET( 1, "ssl_derive_keys", ret ); + return( ret ); + } + + if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK ) + { + SSL_DEBUG_MSG( 2, ( "<= skip write certificate verify" ) ); + ssl->state++; + return( 0 ); + } + + if( ssl->client_auth == 0 || ssl_own_cert( ssl ) == NULL ) + { + SSL_DEBUG_MSG( 2, ( "<= skip write certificate verify" ) ); + ssl->state++; + return( 0 ); + } + + if( ssl_own_key( ssl ) == NULL ) + { + SSL_DEBUG_MSG( 1, ( "got no private key" ) ); + return( POLARSSL_ERR_SSL_PRIVATE_KEY_REQUIRED ); + } + + /* + * Make an RSA signature of the handshake digests + */ + ssl->handshake->calc_verify( ssl, hash ); + +#if defined(POLARSSL_SSL_PROTO_SSL3) || defined(POLARSSL_SSL_PROTO_TLS1) || \ + defined(POLARSSL_SSL_PROTO_TLS1_1) + if( ssl->minor_ver != SSL_MINOR_VERSION_3 ) + { + /* + * digitally-signed struct { + * opaque md5_hash[16]; + * opaque sha_hash[20]; + * }; + * + * md5_hash + * MD5(handshake_messages); + * + * sha_hash + * SHA(handshake_messages); + */ + hashlen = 36; + md_alg = POLARSSL_MD_NONE; + + /* + * For ECDSA, default hash is SHA-1 only + */ + if( pk_can_do( ssl_own_key( ssl ), POLARSSL_PK_ECDSA ) ) + { + hash_start += 16; + hashlen -= 16; + md_alg = POLARSSL_MD_SHA1; + } + } + else +#endif /* POLARSSL_SSL_PROTO_SSL3 || POLARSSL_SSL_PROTO_TLS1 || \ + POLARSSL_SSL_PROTO_TLS1_1 */ +#if defined(POLARSSL_SSL_PROTO_TLS1_2) + if( ssl->minor_ver == SSL_MINOR_VERSION_3 ) + { + /* + * digitally-signed struct { + * opaque handshake_messages[handshake_messages_length]; + * }; + * + * Taking shortcut here. We assume that the server always allows the + * PRF Hash function and has sent it in the allowed signature + * algorithms list received in the Certificate Request message. + * + * Until we encounter a server that does not, we will take this + * shortcut. + * + * Reason: Otherwise we should have running hashes for SHA512 and SHA224 + * in order to satisfy 'weird' needs from the server side. + */ + if( ssl->transform_negotiate->ciphersuite_info->mac == + POLARSSL_MD_SHA384 ) + { + md_alg = POLARSSL_MD_SHA384; + ssl->out_msg[4] = SSL_HASH_SHA384; + } + else + { + md_alg = POLARSSL_MD_SHA256; + ssl->out_msg[4] = SSL_HASH_SHA256; + } + ssl->out_msg[5] = ssl_sig_from_pk( ssl_own_key( ssl ) ); + + /* Info from md_alg will be used instead */ + hashlen = 0; + offset = 2; + } + else +#endif /* POLARSSL_SSL_PROTO_TLS1_2 */ + { + SSL_DEBUG_MSG( 1, ( "should never happen" ) ); + return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); + } + + if( ( ret = pk_sign( ssl_own_key( ssl ), md_alg, hash_start, hashlen, + ssl->out_msg + 6 + offset, &n, + ssl->f_rng, ssl->p_rng ) ) != 0 ) + { + SSL_DEBUG_RET( 1, "pk_sign", ret ); + return( ret ); + } + + ssl->out_msg[4 + offset] = (unsigned char)( n >> 8 ); + ssl->out_msg[5 + offset] = (unsigned char)( n ); + + ssl->out_msglen = 6 + n + offset; + ssl->out_msgtype = SSL_MSG_HANDSHAKE; + ssl->out_msg[0] = SSL_HS_CERTIFICATE_VERIFY; + + ssl->state++; + + if( ( ret = ssl_write_record( ssl ) ) != 0 ) + { + SSL_DEBUG_RET( 1, "ssl_write_record", ret ); + return( ret ); + } + + SSL_DEBUG_MSG( 2, ( "<= write certificate verify" ) ); + + return( ret ); +} +#endif /* !POLARSSL_KEY_EXCHANGE_RSA_ENABLED && + !POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED && + !POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED */ + +#if defined(POLARSSL_SSL_SESSION_TICKETS) +static int ssl_parse_new_session_ticket( ssl_context *ssl ) +{ + int ret; + uint32_t lifetime; + size_t ticket_len; + unsigned char *ticket; + + SSL_DEBUG_MSG( 2, ( "=> parse new session ticket" ) ); + + if( ( ret = ssl_read_record( ssl ) ) != 0 ) + { + SSL_DEBUG_RET( 1, "ssl_read_record", ret ); + return( ret ); + } + + if( ssl->in_msgtype != SSL_MSG_HANDSHAKE ) + { + SSL_DEBUG_MSG( 1, ( "bad new session ticket message" ) ); + return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE ); + } + + /* + * struct { + * uint32 ticket_lifetime_hint; + * opaque ticket<0..2^16-1>; + * } NewSessionTicket; + * + * 0 . 0 handshake message type + * 1 . 3 handshake message length + * 4 . 7 ticket_lifetime_hint + * 8 . 9 ticket_len (n) + * 10 . 9+n ticket content + */ + if( ssl->in_msg[0] != SSL_HS_NEW_SESSION_TICKET || + ssl->in_hslen < 10 ) + { + SSL_DEBUG_MSG( 1, ( "bad new session ticket message" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_NEW_SESSION_TICKET ); + } + + lifetime = ( ssl->in_msg[4] << 24 ) | ( ssl->in_msg[5] << 16 ) | + ( ssl->in_msg[6] << 8 ) | ( ssl->in_msg[7] ); + + ticket_len = ( ssl->in_msg[8] << 8 ) | ( ssl->in_msg[9] ); + + if( ticket_len + 10 != ssl->in_hslen ) + { + SSL_DEBUG_MSG( 1, ( "bad new session ticket message" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_NEW_SESSION_TICKET ); + } + + SSL_DEBUG_MSG( 3, ( "ticket length: %d", ticket_len ) ); + + /* We're not waiting for a NewSessionTicket message any more */ + ssl->handshake->new_session_ticket = 0; + + /* + * Zero-length ticket means the server changed his mind and doesn't want + * to send a ticket after all, so just forget it + */ + if( ticket_len == 0 ) + return( 0 ); + + polarssl_zeroize( ssl->session_negotiate->ticket, + ssl->session_negotiate->ticket_len ); + polarssl_free( ssl->session_negotiate->ticket ); + ssl->session_negotiate->ticket = NULL; + ssl->session_negotiate->ticket_len = 0; + + if( ( ticket = polarssl_malloc( ticket_len ) ) == NULL ) + { + SSL_DEBUG_MSG( 1, ( "ticket malloc failed" ) ); + return( POLARSSL_ERR_SSL_MALLOC_FAILED ); + } + + memcpy( ticket, ssl->in_msg + 10, ticket_len ); + + ssl->session_negotiate->ticket = ticket; + ssl->session_negotiate->ticket_len = ticket_len; + ssl->session_negotiate->ticket_lifetime = lifetime; + + /* + * RFC 5077 section 3.4: + * "If the client receives a session ticket from the server, then it + * discards any Session ID that was sent in the ServerHello." + */ + SSL_DEBUG_MSG( 3, ( "ticket in use, discarding session id" ) ); + ssl->session_negotiate->length = 0; + + SSL_DEBUG_MSG( 2, ( "<= parse new session ticket" ) ); + + return( 0 ); +} +#endif /* POLARSSL_SSL_SESSION_TICKETS */ + +/* + * SSL handshake -- client side -- single step + */ +int ssl_handshake_client_step( ssl_context *ssl ) +{ + int ret = 0; + + if( ssl->state == SSL_HANDSHAKE_OVER ) + return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); + + SSL_DEBUG_MSG( 2, ( "client state: %d", ssl->state ) ); + + if( ( ret = ssl_flush_output( ssl ) ) != 0 ) + return( ret ); + + switch( ssl->state ) + { + case SSL_HELLO_REQUEST: + ssl->state = SSL_CLIENT_HELLO; + break; + + /* + * ==> ClientHello + */ + case SSL_CLIENT_HELLO: + ret = ssl_write_client_hello( ssl ); + break; + + /* + * <== ServerHello + * Certificate + * ( ServerKeyExchange ) + * ( CertificateRequest ) + * ServerHelloDone + */ + case SSL_SERVER_HELLO: + ret = ssl_parse_server_hello( ssl ); + break; + + case SSL_SERVER_CERTIFICATE: + ret = ssl_parse_certificate( ssl ); + break; + + case SSL_SERVER_KEY_EXCHANGE: + ret = ssl_parse_server_key_exchange( ssl ); + break; + + case SSL_CERTIFICATE_REQUEST: + ret = ssl_parse_certificate_request( ssl ); + break; + + case SSL_SERVER_HELLO_DONE: + ret = ssl_parse_server_hello_done( ssl ); + break; + + /* + * ==> ( Certificate/Alert ) + * ClientKeyExchange + * ( CertificateVerify ) + * ChangeCipherSpec + * Finished + */ + case SSL_CLIENT_CERTIFICATE: + ret = ssl_write_certificate( ssl ); + break; + + case SSL_CLIENT_KEY_EXCHANGE: + ret = ssl_write_client_key_exchange( ssl ); + break; + + case SSL_CERTIFICATE_VERIFY: + ret = ssl_write_certificate_verify( ssl ); + break; + + case SSL_CLIENT_CHANGE_CIPHER_SPEC: + ret = ssl_write_change_cipher_spec( ssl ); + break; + + case SSL_CLIENT_FINISHED: + ret = ssl_write_finished( ssl ); + break; + + /* + * <== ( NewSessionTicket ) + * ChangeCipherSpec + * Finished + */ + case SSL_SERVER_CHANGE_CIPHER_SPEC: +#if defined(POLARSSL_SSL_SESSION_TICKETS) + if( ssl->handshake->new_session_ticket != 0 ) + ret = ssl_parse_new_session_ticket( ssl ); + else +#endif + ret = ssl_parse_change_cipher_spec( ssl ); + break; + + case SSL_SERVER_FINISHED: + ret = ssl_parse_finished( ssl ); + break; + + case SSL_FLUSH_BUFFERS: + SSL_DEBUG_MSG( 2, ( "handshake: done" ) ); + ssl->state = SSL_HANDSHAKE_WRAPUP; + break; + + case SSL_HANDSHAKE_WRAPUP: + ssl_handshake_wrapup( ssl ); + break; + + default: + SSL_DEBUG_MSG( 1, ( "invalid state %d", ssl->state ) ); + return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); + } + + return( ret ); +} +#endif /* POLARSSL_SSL_CLI_C */