/* * SSLv3/TLSv1 client-side functions * * Copyright (C) 2006-2012, Brainspark B.V. * * This file is part of PolarSSL (http://www.polarssl.org) * Lead Maintainer: Paul Bakker * * All rights reserved. * * 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. */ #include "polarssl/config.h" #if defined(POLARSSL_SSL_CLI_C) #include "polarssl/debug.h" #include "polarssl/ssl.h" #include #include #include #if defined(POLARSSL_SHA4_C) #include "polarssl/sha4.h" #endif static int ssl_write_client_hello( ssl_context *ssl ) { int ret; size_t i, n, ext_len = 0; unsigned char *buf; unsigned char *p; time_t t; unsigned char sig_alg_list[20]; size_t sig_alg_len = 0; SSL_DEBUG_MSG( 2, ( "=> write client hello" ) ); if( ssl->renegotiation == SSL_INITIAL_HANDSHAKE ) { 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_MAJOR_VERSION_3; ssl->max_minor_ver = SSL_MINOR_VERSION_3; } /* * 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] ) ); 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 ) ); 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( ssl->renegotiation != SSL_INITIAL_HANDSHAKE || n < 16 || n > 32 || ssl->handshake->resume == 0 ) n = 0; *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 ); for( n = 0; ssl->ciphersuites[ssl->minor_ver][n] != 0; n++ ); if( ssl->renegotiation == SSL_INITIAL_HANDSHAKE ) n++; *p++ = (unsigned char)( n >> 7 ); *p++ = (unsigned char)( n << 1 ); /* * Add TLS_EMPTY_RENEGOTIATION_INFO_SCSV */ if( ssl->renegotiation == SSL_INITIAL_HANDSHAKE ) { *p++ = (unsigned char)( SSL_EMPTY_RENEGOTIATION_INFO >> 8 ); *p++ = (unsigned char)( SSL_EMPTY_RENEGOTIATION_INFO ); n--; } SSL_DEBUG_MSG( 3, ( "client hello, got %d ciphersuites", n ) ); for( i = 0; i < n; i++ ) { SSL_DEBUG_MSG( 3, ( "client hello, add ciphersuite: %2d", ssl->ciphersuites[ssl->minor_ver][i] ) ); *p++ = (unsigned char)( ssl->ciphersuites[ssl->minor_ver][i] >> 8 ); *p++ = (unsigned char)( ssl->ciphersuites[ssl->minor_ver][i] ); } #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 if ( ssl->hostname != NULL ) { SSL_DEBUG_MSG( 3, ( "client hello, prepping for server name extension: %s", ssl->hostname ) ); ext_len += ssl->hostname_len + 9; } if( ssl->renegotiation == SSL_RENEGOTIATION ) { SSL_DEBUG_MSG( 3, ( "client hello, prepping for renegotiation extension" ) ); ext_len += 5 + ssl->verify_data_len; } /* * Prepare signature_algorithms extension (TLS 1.2) */ if( ssl->max_minor_ver == SSL_MINOR_VERSION_3 ) { #if defined(POLARSSL_SHA4_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_SHA2_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 ext_len += 6 + sig_alg_len; } SSL_DEBUG_MSG( 3, ( "client hello, total extension length: %d", ext_len ) ); *p++ = (unsigned char)( ( ext_len >> 8 ) & 0xFF ); *p++ = (unsigned char)( ( ext_len ) & 0xFF ); if ( ssl->hostname != NULL ) { /* * 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; */ SSL_DEBUG_MSG( 3, ( "client hello, adding server name extension: %s", ssl->hostname ) ); *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 ); p += ssl->hostname_len; } if( ssl->renegotiation == SSL_RENEGOTIATION ) { /* * Secure renegotiation */ SSL_DEBUG_MSG( 3, ( "client hello, renegotiation info extension" ) ); *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 ); p += ssl->verify_data_len; } if( ssl->max_minor_ver == SSL_MINOR_VERSION_3 ) { /* * 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>; */ SSL_DEBUG_MSG( 3, ( "client hello, adding signature_algorithms extension" ) ); *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 ); memcpy( p, sig_alg_list, sig_alg_len ); p += sig_alg_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, unsigned char *buf, size_t len ) { int ret; if( ssl->renegotiation == SSL_INITIAL_HANDSHAKE ) { if( len != 1 || buf[0] != 0x0 ) { SSL_DEBUG_MSG( 1, ( "non-zero length renegotiated connection field" ) ); 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; } else { if( len != 1 + ssl->verify_data_len * 2 || buf[0] != ssl->verify_data_len * 2 || memcmp( buf + 1, ssl->own_verify_data, ssl->verify_data_len ) != 0 || memcmp( buf + 1 + ssl->verify_data_len, ssl->peer_verify_data, ssl->verify_data_len ) != 0 ) { SSL_DEBUG_MSG( 1, ( "non-matching renegotiated connection field" ) ); if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 ) return( ret ); return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); } } return( 0 ); } static int ssl_parse_server_hello( ssl_context *ssl ) { #if defined(POLARSSL_DEBUG_C) time_t t; #endif int ret, i, comp; size_t n; size_t ext_len = 0; unsigned char *buf, *ext; int renegotiation_info_seen = 0; int handshake_failure = 0; 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 ) { 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 = ( (time_t) buf[6] << 24 ) | ( (time_t) buf[7] << 16 ) | ( (time_t) buf[8] << 8 ) | ( (time_t) buf[9] ); #endif memcpy( ssl->handshake->randbytes + 32, buf + 6, 32 ); n = buf[38]; SSL_DEBUG_MSG( 3, ( "server hello, current time: %lu", t ) ); 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 > 42 + 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 ); } } i = ( buf[39 + n] << 8 ) | buf[40 + n]; comp = buf[41 + n]; /* * Initialize update checksum functions */ ssl_optimize_checksum( ssl, i ); 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->renegotiation != SSL_INITIAL_HANDSHAKE || ssl->handshake->resume == 0 || n == 0 || 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; ssl->session_negotiate->start = time( NULL ); 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] ) ); i = 0; while( 1 ) { if( ssl->ciphersuites[ssl->minor_ver][i] == 0 ) { SSL_DEBUG_MSG( 1, ( "bad server hello message" ) ); return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO ); } if( ssl->ciphersuites[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; 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" ) ); renegotiation_info_seen = 1; if( ( ret = ssl_parse_renegotiation_info( ssl, ext + 4, ext_size ) ) != 0 ) return( ret ); break; 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; } 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; } 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 ); } static int ssl_parse_server_key_exchange( ssl_context *ssl ) { #if defined(POLARSSL_DHM_C) int ret; size_t n; unsigned char *p, *end; unsigned char hash[64]; md5_context md5; sha1_context sha1; int hash_id = SIG_RSA_RAW; unsigned int hashlen = 0; #endif SSL_DEBUG_MSG( 2, ( "=> parse server key exchange" ) ); if( ssl->session_negotiate->ciphersuite != TLS_DHE_RSA_WITH_DES_CBC_SHA && ssl->session_negotiate->ciphersuite != TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA && ssl->session_negotiate->ciphersuite != TLS_DHE_RSA_WITH_AES_128_CBC_SHA && ssl->session_negotiate->ciphersuite != TLS_DHE_RSA_WITH_AES_256_CBC_SHA && ssl->session_negotiate->ciphersuite != TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 && ssl->session_negotiate->ciphersuite != TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 && ssl->session_negotiate->ciphersuite != TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA && ssl->session_negotiate->ciphersuite != TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA && ssl->session_negotiate->ciphersuite != TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA256 && ssl->session_negotiate->ciphersuite != TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA256 && ssl->session_negotiate->ciphersuite != TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 && ssl->session_negotiate->ciphersuite != TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 ) { SSL_DEBUG_MSG( 2, ( "<= skip parse server key exchange" ) ); ssl->state++; return( 0 ); } #if !defined(POLARSSL_DHM_C) SSL_DEBUG_MSG( 1, ( "support for dhm in not available" ) ); return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE ); #else 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 ); } if( ssl->in_msg[0] != SSL_HS_SERVER_KEY_EXCHANGE ) { SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) ); return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE ); } SSL_DEBUG_BUF( 3, "server key exchange", ssl->in_msg + 4, ssl->in_hslen - 4 ); /* * 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; */ p = ssl->in_msg + 4; end = ssl->in_msg + ssl->in_hslen; if( ( ret = dhm_read_params( &ssl->handshake->dhm_ctx, &p, end ) ) != 0 ) { SSL_DEBUG_MSG( 2, ( "DHM Read Params returned -0x%x", -ret ) ); SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) ); return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE ); } if( ssl->minor_ver == SSL_MINOR_VERSION_3 ) { if( p[1] != SSL_SIG_RSA ) { SSL_DEBUG_MSG( 2, ( "server used unsupported SignatureAlgorithm %d", p[1] ) ); SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) ); return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE ); } switch( p[0] ) { #if defined(POLARSSL_MD5_C) case SSL_HASH_MD5: hash_id = SIG_RSA_MD5; break; #endif #if defined(POLARSSL_SHA1_C) case SSL_HASH_SHA1: hash_id = SIG_RSA_SHA1; break; #endif #if defined(POLARSSL_SHA2_C) case SSL_HASH_SHA224: hash_id = SIG_RSA_SHA224; break; case SSL_HASH_SHA256: hash_id = SIG_RSA_SHA256; break; #endif #if defined(POLARSSL_SHA4_C) case SSL_HASH_SHA384: hash_id = SIG_RSA_SHA384; break; case SSL_HASH_SHA512: hash_id = SIG_RSA_SHA512; break; #endif default: SSL_DEBUG_MSG( 2, ( "Server used unsupported HashAlgorithm %d", p[0] ) ); SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) ); 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; } n = ( p[0] << 8 ) | p[1]; p += 2; if( end != p + n ) { SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) ); return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE ); } if( (unsigned int)( end - p ) != ssl->session_negotiate->peer_cert->rsa.len ) { SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) ); return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE ); } if( ssl->handshake->dhm_ctx.len < 64 || ssl->handshake->dhm_ctx.len > 512 ) { SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) ); 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 ); if( ssl->minor_ver != SSL_MINOR_VERSION_3 ) { /* * 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); */ n = ssl->in_hslen - ( end - p ) - 6; md5_starts( &md5 ); md5_update( &md5, ssl->handshake->randbytes, 64 ); md5_update( &md5, ssl->in_msg + 4, n ); md5_finish( &md5, hash ); sha1_starts( &sha1 ); sha1_update( &sha1, ssl->handshake->randbytes, 64 ); sha1_update( &sha1, ssl->in_msg + 4, n ); sha1_finish( &sha1, hash + 16 ); hash_id = SIG_RSA_RAW; hashlen = 36; } else { sha2_context sha2; #if defined(POLARSSL_SHA4_C) sha4_context sha4; #endif n = ssl->in_hslen - ( end - p ) - 8; /* * digitally-signed struct { * opaque client_random[32]; * opaque server_random[32]; * ServerDHParams params; * }; */ switch( hash_id ) { #if defined(POLARSSL_MD5_C) case SIG_RSA_MD5: md5_starts( &md5 ); md5_update( &md5, ssl->handshake->randbytes, 64 ); md5_update( &md5, ssl->in_msg + 4, n ); md5_finish( &md5, hash ); hashlen = 16; break; #endif #if defined(POLARSSL_SHA1_C) case SIG_RSA_SHA1: sha1_starts( &sha1 ); sha1_update( &sha1, ssl->handshake->randbytes, 64 ); sha1_update( &sha1, ssl->in_msg + 4, n ); sha1_finish( &sha1, hash ); hashlen = 20; break; #endif #if defined(POLARSSL_SHA2_C) case SIG_RSA_SHA224: sha2_starts( &sha2, 1 ); sha2_update( &sha2, ssl->handshake->randbytes, 64 ); sha2_update( &sha2, ssl->in_msg + 4, n ); sha2_finish( &sha2, hash ); hashlen = 28; break; case SIG_RSA_SHA256: sha2_starts( &sha2, 0 ); sha2_update( &sha2, ssl->handshake->randbytes, 64 ); sha2_update( &sha2, ssl->in_msg + 4, n ); sha2_finish( &sha2, hash ); hashlen = 32; break; #endif #if defined(POLARSSL_SHA4_C) case SIG_RSA_SHA384: sha4_starts( &sha4, 1 ); sha4_update( &sha4, ssl->handshake->randbytes, 64 ); sha4_update( &sha4, ssl->in_msg + 4, n ); sha4_finish( &sha4, hash ); hashlen = 48; break; case SIG_RSA_SHA512: sha4_starts( &sha4, 0 ); sha4_update( &sha4, ssl->handshake->randbytes, 64 ); sha4_update( &sha4, ssl->in_msg + 4, n ); sha4_finish( &sha4, hash ); hashlen = 64; break; #endif } } SSL_DEBUG_BUF( 3, "parameters hash", hash, hashlen ); if( ( ret = rsa_pkcs1_verify( &ssl->session_negotiate->peer_cert->rsa, RSA_PUBLIC, hash_id, hashlen, hash, p ) ) != 0 ) { SSL_DEBUG_RET( 1, "rsa_pkcs1_verify", ret ); return( ret ); } ssl->state++; SSL_DEBUG_MSG( 2, ( "<= parse server key exchange" ) ); return( 0 ); #endif } 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, sig_alg_len = 0, dn_len = 0; SSL_DEBUG_MSG( 2, ( "=> parse certificate request" ) ); /* * 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( ( 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->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; // 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( *p == SSL_CERT_TYPE_RSA_SIGN ) { ssl->handshake->cert_type = SSL_CERT_TYPE_RSA_SIGN; break; } cert_type_len--; p++; } if( ssl->handshake->cert_type == 0 ) { SSL_DEBUG_MSG( 1, ( "no known cert_type provided" ) ); return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST ); } if( ssl->minor_ver == SSL_MINOR_VERSION_3 ) { 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 ); } } 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 ); } static int ssl_parse_server_hello_done( ssl_context *ssl ) { int ret; SSL_DEBUG_MSG( 2, ( "=> parse server hello done" ) ); if( ssl->client_auth != 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 ); } } 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; SSL_DEBUG_MSG( 2, ( "=> write client key exchange" ) ); if( ssl->session_negotiate->ciphersuite == TLS_DHE_RSA_WITH_DES_CBC_SHA || ssl->session_negotiate->ciphersuite == TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA || ssl->session_negotiate->ciphersuite == TLS_DHE_RSA_WITH_AES_128_CBC_SHA || ssl->session_negotiate->ciphersuite == TLS_DHE_RSA_WITH_AES_256_CBC_SHA || ssl->session_negotiate->ciphersuite == TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 || ssl->session_negotiate->ciphersuite == TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 || ssl->session_negotiate->ciphersuite == TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA || ssl->session_negotiate->ciphersuite == TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA || ssl->session_negotiate->ciphersuite == TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA256 || ssl->session_negotiate->ciphersuite == TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA256 || ssl->session_negotiate->ciphersuite == TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 || ssl->session_negotiate->ciphersuite == TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 ) { #if !defined(POLARSSL_DHM_C) SSL_DEBUG_MSG( 1, ( "support for dhm in not available" ) ); return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE ); #else /* * 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, 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 = ssl->handshake->dhm_ctx.len; if( ( ret = dhm_calc_secret( &ssl->handshake->dhm_ctx, ssl->handshake->premaster, &ssl->handshake->pmslen ) ) != 0 ) { SSL_DEBUG_RET( 1, "dhm_calc_secret", ret ); return( ret ); } SSL_DEBUG_MPI( 3, "DHM: K ", &ssl->handshake->dhm_ctx.K ); #endif } else { /* * RSA key exchange -- send rsa_public(pkcs1 v1.5(premaster)) */ ssl->handshake->premaster[0] = (unsigned char) ssl->max_major_ver; ssl->handshake->premaster[1] = (unsigned char) ssl->max_minor_ver; ssl->handshake->pmslen = 48; ret = ssl->f_rng( ssl->p_rng, ssl->handshake->premaster + 2, ssl->handshake->pmslen - 2 ); if( ret != 0 ) return( ret ); i = 4; n = ssl->session_negotiate->peer_cert->rsa.len; if( ssl->minor_ver != SSL_MINOR_VERSION_0 ) { i += 2; ssl->out_msg[4] = (unsigned char)( n >> 8 ); ssl->out_msg[5] = (unsigned char)( n ); } ret = rsa_pkcs1_encrypt( &ssl->session_negotiate->peer_cert->rsa, ssl->f_rng, ssl->p_rng, RSA_PUBLIC, ssl->handshake->pmslen, ssl->handshake->premaster, ssl->out_msg + i ); if( ret != 0 ) { SSL_DEBUG_RET( 1, "rsa_pkcs1_encrypt", ret ); return( ret ); } } if( ( ret = ssl_derive_keys( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_derive_keys", ret ); return( ret ); } 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 ); } static int ssl_write_certificate_verify( ssl_context *ssl ) { int ret = 0; size_t n = 0, offset = 0; unsigned char hash[48]; int hash_id = SIG_RSA_RAW; unsigned int hashlen = 36; SSL_DEBUG_MSG( 2, ( "=> write certificate verify" ) ); if( ssl->client_auth == 0 || ssl->own_cert == NULL ) { SSL_DEBUG_MSG( 2, ( "<= skip write certificate verify" ) ); ssl->state++; return( 0 ); } if( ssl->rsa_key == 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( 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; hash_id = SIG_RSA_RAW; } else { /* * 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->session_negotiate->ciphersuite == TLS_RSA_WITH_AES_256_GCM_SHA384 || ssl->session_negotiate->ciphersuite == TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 ) { hash_id = SIG_RSA_SHA384; hashlen = 48; ssl->out_msg[4] = SSL_HASH_SHA384; ssl->out_msg[5] = SSL_SIG_RSA; } else { hash_id = SIG_RSA_SHA256; hashlen = 32; ssl->out_msg[4] = SSL_HASH_SHA256; ssl->out_msg[5] = SSL_SIG_RSA; } offset = 2; } if ( ssl->rsa_key ) n = ssl->rsa_key_len ( ssl->rsa_key ); ssl->out_msg[4 + offset] = (unsigned char)( n >> 8 ); ssl->out_msg[5 + offset] = (unsigned char)( n ); if( ssl->rsa_key ) { ret = ssl->rsa_sign( ssl->rsa_key, ssl->f_rng, ssl->p_rng, RSA_PRIVATE, hash_id, hashlen, hash, ssl->out_msg + 6 + offset ); } if (ret != 0) { SSL_DEBUG_RET( 1, "pkcs1_sign", ret ); return( ret ); } 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( 0 ); } /* * 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; /* * <== ChangeCipherSpec * Finished */ case SSL_SERVER_CHANGE_CIPHER_SPEC: 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