| /* |
| * SSLv3/TLSv1 server-side functions |
| * |
| * Copyright (C) 2006-2013, Brainspark B.V. |
| * |
| * This file is part of PolarSSL (http://www.polarssl.org) |
| * Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org> |
| * |
| * 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_SRV_C) |
| |
| #include "polarssl/debug.h" |
| #include "polarssl/ssl.h" |
| |
| #include <stdlib.h> |
| #include <stdio.h> |
| #include <time.h> |
| |
| static int ssl_parse_servername_ext( ssl_context *ssl, |
| const unsigned char *buf, |
| size_t len ) |
| { |
| int ret; |
| size_t servername_list_size, hostname_len; |
| const unsigned char *p; |
| |
| servername_list_size = ( ( buf[0] << 8 ) | ( buf[1] ) ); |
| if( servername_list_size + 2 != len ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| p = buf + 2; |
| while( servername_list_size > 0 ) |
| { |
| hostname_len = ( ( p[1] << 8 ) | p[2] ); |
| if( hostname_len + 3 > servername_list_size ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| if( p[0] == TLS_EXT_SERVERNAME_HOSTNAME ) |
| { |
| ret = ssl->f_sni( ssl->p_sni, ssl, p + 3, hostname_len ); |
| if( ret != 0 ) |
| { |
| ssl_send_alert_message( ssl, SSL_ALERT_LEVEL_FATAL, |
| SSL_ALERT_MSG_UNRECOGNIZED_NAME ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| return( 0 ); |
| } |
| |
| servername_list_size -= hostname_len + 3; |
| p += hostname_len + 3; |
| } |
| |
| if( servername_list_size != 0 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| return( 0 ); |
| } |
| |
| static int ssl_parse_renegotiation_info( ssl_context *ssl, |
| const 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_CLIENT_HELLO ); |
| } |
| |
| ssl->secure_renegotiation = SSL_SECURE_RENEGOTIATION; |
| } |
| else |
| { |
| if( len != 1 + ssl->verify_data_len || |
| buf[0] != ssl->verify_data_len || |
| memcmp( buf + 1, 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_CLIENT_HELLO ); |
| } |
| } |
| |
| return( 0 ); |
| } |
| |
| static int ssl_parse_signature_algorithms_ext( ssl_context *ssl, |
| const unsigned char *buf, |
| size_t len ) |
| { |
| size_t sig_alg_list_size; |
| const unsigned char *p; |
| |
| sig_alg_list_size = ( ( buf[0] << 8 ) | ( buf[1] ) ); |
| if( sig_alg_list_size + 2 != len || |
| sig_alg_list_size %2 != 0 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| p = buf + 2; |
| while( sig_alg_list_size > 0 ) |
| { |
| if( p[1] != SSL_SIG_RSA ) |
| { |
| sig_alg_list_size -= 2; |
| p += 2; |
| continue; |
| } |
| #if defined(POLARSSL_SHA4_C) |
| if( p[0] == SSL_HASH_SHA512 ) |
| { |
| ssl->handshake->sig_alg = SSL_HASH_SHA512; |
| break; |
| } |
| if( p[0] == SSL_HASH_SHA384 ) |
| { |
| ssl->handshake->sig_alg = SSL_HASH_SHA384; |
| break; |
| } |
| #endif |
| #if defined(POLARSSL_SHA2_C) |
| if( p[0] == SSL_HASH_SHA256 ) |
| { |
| ssl->handshake->sig_alg = SSL_HASH_SHA256; |
| break; |
| } |
| if( p[0] == SSL_HASH_SHA224 ) |
| { |
| ssl->handshake->sig_alg = SSL_HASH_SHA224; |
| break; |
| } |
| #endif |
| if( p[0] == SSL_HASH_SHA1 ) |
| { |
| ssl->handshake->sig_alg = SSL_HASH_SHA1; |
| break; |
| } |
| if( p[0] == SSL_HASH_MD5 ) |
| { |
| ssl->handshake->sig_alg = SSL_HASH_MD5; |
| break; |
| } |
| |
| sig_alg_list_size -= 2; |
| p += 2; |
| } |
| |
| SSL_DEBUG_MSG( 3, ( "client hello v3, signature_algorithm ext: %d", |
| ssl->handshake->sig_alg ) ); |
| |
| return( 0 ); |
| } |
| |
| #if defined(POLARSSL_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO) |
| static int ssl_parse_client_hello_v2( ssl_context *ssl ) |
| { |
| int ret; |
| unsigned int i, j; |
| size_t n; |
| unsigned int ciph_len, sess_len, chal_len; |
| unsigned char *buf, *p; |
| |
| SSL_DEBUG_MSG( 2, ( "=> parse client hello v2" ) ); |
| |
| if( ssl->renegotiation != SSL_INITIAL_HANDSHAKE ) |
| { |
| SSL_DEBUG_MSG( 1, ( "client hello v2 illegal for renegotiation" ) ); |
| |
| if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 ) |
| return( ret ); |
| |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| buf = ssl->in_hdr; |
| |
| SSL_DEBUG_BUF( 4, "record header", buf, 5 ); |
| |
| SSL_DEBUG_MSG( 3, ( "client hello v2, message type: %d", |
| buf[2] ) ); |
| SSL_DEBUG_MSG( 3, ( "client hello v2, message len.: %d", |
| ( ( buf[0] & 0x7F ) << 8 ) | buf[1] ) ); |
| SSL_DEBUG_MSG( 3, ( "client hello v2, max. version: [%d:%d]", |
| buf[3], buf[4] ) ); |
| |
| /* |
| * SSLv2 Client Hello |
| * |
| * Record layer: |
| * 0 . 1 message length |
| * |
| * SSL layer: |
| * 2 . 2 message type |
| * 3 . 4 protocol version |
| */ |
| if( buf[2] != SSL_HS_CLIENT_HELLO || |
| buf[3] != SSL_MAJOR_VERSION_3 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| n = ( ( buf[0] << 8 ) | buf[1] ) & 0x7FFF; |
| |
| if( n < 17 || n > 512 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| ssl->major_ver = SSL_MAJOR_VERSION_3; |
| ssl->minor_ver = ( buf[4] <= SSL_MINOR_VERSION_3 ) |
| ? buf[4] : SSL_MINOR_VERSION_3; |
| |
| if( ssl->minor_ver < ssl->min_minor_ver ) |
| { |
| SSL_DEBUG_MSG( 1, ( "client only supports ssl smaller than minimum" |
| " [%d:%d] < [%d:%d]", ssl->major_ver, ssl->minor_ver, |
| ssl->min_major_ver, ssl->min_minor_ver ) ); |
| |
| ssl_send_alert_message( ssl, SSL_ALERT_LEVEL_FATAL, |
| SSL_ALERT_MSG_PROTOCOL_VERSION ); |
| return( POLARSSL_ERR_SSL_BAD_HS_PROTOCOL_VERSION ); |
| } |
| |
| ssl->max_major_ver = buf[3]; |
| ssl->max_minor_ver = buf[4]; |
| |
| if( ( ret = ssl_fetch_input( ssl, 2 + n ) ) != 0 ) |
| { |
| SSL_DEBUG_RET( 1, "ssl_fetch_input", ret ); |
| return( ret ); |
| } |
| |
| ssl->handshake->update_checksum( ssl, buf + 2, n ); |
| |
| buf = ssl->in_msg; |
| n = ssl->in_left - 5; |
| |
| /* |
| * 0 . 1 ciphersuitelist length |
| * 2 . 3 session id length |
| * 4 . 5 challenge length |
| * 6 . .. ciphersuitelist |
| * .. . .. session id |
| * .. . .. challenge |
| */ |
| SSL_DEBUG_BUF( 4, "record contents", buf, n ); |
| |
| ciph_len = ( buf[0] << 8 ) | buf[1]; |
| sess_len = ( buf[2] << 8 ) | buf[3]; |
| chal_len = ( buf[4] << 8 ) | buf[5]; |
| |
| SSL_DEBUG_MSG( 3, ( "ciph_len: %d, sess_len: %d, chal_len: %d", |
| ciph_len, sess_len, chal_len ) ); |
| |
| /* |
| * Make sure each parameter length is valid |
| */ |
| if( ciph_len < 3 || ( ciph_len % 3 ) != 0 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| if( sess_len > 32 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| if( chal_len < 8 || chal_len > 32 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| if( n != 6 + ciph_len + sess_len + chal_len ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| SSL_DEBUG_BUF( 3, "client hello, ciphersuitelist", |
| buf + 6, ciph_len ); |
| SSL_DEBUG_BUF( 3, "client hello, session id", |
| buf + 6 + ciph_len, sess_len ); |
| SSL_DEBUG_BUF( 3, "client hello, challenge", |
| buf + 6 + ciph_len + sess_len, chal_len ); |
| |
| p = buf + 6 + ciph_len; |
| ssl->session_negotiate->length = sess_len; |
| memset( ssl->session_negotiate->id, 0, sizeof( ssl->session_negotiate->id ) ); |
| memcpy( ssl->session_negotiate->id, p, ssl->session_negotiate->length ); |
| |
| p += sess_len; |
| memset( ssl->handshake->randbytes, 0, 64 ); |
| memcpy( ssl->handshake->randbytes + 32 - chal_len, p, chal_len ); |
| |
| /* |
| * Check for TLS_EMPTY_RENEGOTIATION_INFO_SCSV |
| */ |
| for( i = 0, p = buf + 6; i < ciph_len; i += 3, p += 3 ) |
| { |
| if( p[0] == 0 && p[1] == 0 && p[2] == SSL_EMPTY_RENEGOTIATION_INFO ) |
| { |
| SSL_DEBUG_MSG( 3, ( "received TLS_EMPTY_RENEGOTIATION_INFO " ) ); |
| if( ssl->renegotiation == SSL_RENEGOTIATION ) |
| { |
| SSL_DEBUG_MSG( 1, ( "received RENEGOTIATION SCSV during renegotiation" ) ); |
| |
| if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 ) |
| return( ret ); |
| |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| ssl->secure_renegotiation = SSL_SECURE_RENEGOTIATION; |
| break; |
| } |
| } |
| |
| for( i = 0; ssl->ciphersuites[i] != 0; i++ ) |
| { |
| for( j = 0, p = buf + 6; j < ciph_len; j += 3, p += 3 ) |
| { |
| if( p[0] == 0 && |
| p[1] == 0 && |
| p[2] == ssl->ciphersuites[i] ) |
| goto have_ciphersuite_v2; |
| } |
| } |
| |
| SSL_DEBUG_MSG( 1, ( "got no ciphersuites in common" ) ); |
| |
| return( POLARSSL_ERR_SSL_NO_CIPHER_CHOSEN ); |
| |
| have_ciphersuite_v2: |
| ssl->session_negotiate->ciphersuite = ssl->ciphersuites[i]; |
| ssl_optimize_checksum( ssl, ssl->session_negotiate->ciphersuite ); |
| |
| /* |
| * SSLv2 Client Hello relevant 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" ) ); |
| |
| if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 ) |
| return( ret ); |
| |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| ssl->in_left = 0; |
| ssl->state++; |
| |
| SSL_DEBUG_MSG( 2, ( "<= parse client hello v2" ) ); |
| |
| return( 0 ); |
| } |
| #endif /* POLARSSL_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO */ |
| |
| static int ssl_parse_client_hello( ssl_context *ssl ) |
| { |
| int ret; |
| unsigned int i, j; |
| size_t n; |
| unsigned int ciph_len, sess_len; |
| unsigned int comp_len; |
| unsigned int ext_len = 0; |
| unsigned char *buf, *p, *ext; |
| int renegotiation_info_seen = 0; |
| int handshake_failure = 0; |
| |
| SSL_DEBUG_MSG( 2, ( "=> parse client hello" ) ); |
| |
| if( ssl->renegotiation == SSL_INITIAL_HANDSHAKE && |
| ( ret = ssl_fetch_input( ssl, 5 ) ) != 0 ) |
| { |
| SSL_DEBUG_RET( 1, "ssl_fetch_input", ret ); |
| return( ret ); |
| } |
| |
| buf = ssl->in_hdr; |
| |
| #if defined(POLARSSL_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO) |
| if( ( buf[0] & 0x80 ) != 0 ) |
| return ssl_parse_client_hello_v2( ssl ); |
| #endif |
| |
| SSL_DEBUG_BUF( 4, "record header", buf, 5 ); |
| |
| SSL_DEBUG_MSG( 3, ( "client hello v3, message type: %d", |
| buf[0] ) ); |
| SSL_DEBUG_MSG( 3, ( "client hello v3, message len.: %d", |
| ( buf[3] << 8 ) | buf[4] ) ); |
| SSL_DEBUG_MSG( 3, ( "client hello v3, protocol ver: [%d:%d]", |
| buf[1], buf[2] ) ); |
| |
| /* |
| * SSLv3 Client Hello |
| * |
| * Record layer: |
| * 0 . 0 message type |
| * 1 . 2 protocol version |
| * 3 . 4 message length |
| */ |
| if( buf[0] != SSL_MSG_HANDSHAKE || |
| buf[1] != SSL_MAJOR_VERSION_3 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| n = ( buf[3] << 8 ) | buf[4]; |
| |
| if( n < 45 || n > 512 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| if( ssl->renegotiation == SSL_INITIAL_HANDSHAKE && |
| ( ret = ssl_fetch_input( ssl, 5 + n ) ) != 0 ) |
| { |
| SSL_DEBUG_RET( 1, "ssl_fetch_input", ret ); |
| return( ret ); |
| } |
| |
| buf = ssl->in_msg; |
| if( !ssl->renegotiation ) |
| n = ssl->in_left - 5; |
| else |
| n = ssl->in_msglen; |
| |
| ssl->handshake->update_checksum( ssl, buf, n ); |
| |
| /* |
| * SSL layer: |
| * 0 . 0 handshake type |
| * 1 . 3 handshake length |
| * 4 . 5 protocol version |
| * 6 . 9 UNIX time() |
| * 10 . 37 random bytes |
| * 38 . 38 session id length |
| * 39 . 38+x session id |
| * 39+x . 40+x ciphersuitelist length |
| * 41+x . .. ciphersuitelist |
| * .. . .. compression alg. |
| * .. . .. extensions |
| */ |
| SSL_DEBUG_BUF( 4, "record contents", buf, n ); |
| |
| SSL_DEBUG_MSG( 3, ( "client hello v3, handshake type: %d", |
| buf[0] ) ); |
| SSL_DEBUG_MSG( 3, ( "client hello v3, handshake len.: %d", |
| ( buf[1] << 16 ) | ( buf[2] << 8 ) | buf[3] ) ); |
| SSL_DEBUG_MSG( 3, ( "client hello v3, max. version: [%d:%d]", |
| buf[4], buf[5] ) ); |
| |
| /* |
| * Check the handshake type and protocol version |
| */ |
| if( buf[0] != SSL_HS_CLIENT_HELLO || |
| buf[4] != SSL_MAJOR_VERSION_3 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| ssl->major_ver = SSL_MAJOR_VERSION_3; |
| ssl->minor_ver = ( buf[5] <= SSL_MINOR_VERSION_3 ) |
| ? buf[5] : SSL_MINOR_VERSION_3; |
| |
| if( ssl->minor_ver < ssl->min_minor_ver ) |
| { |
| SSL_DEBUG_MSG( 1, ( "client only supports ssl smaller than minimum" |
| " [%d:%d] < [%d:%d]", ssl->major_ver, ssl->minor_ver, |
| ssl->min_major_ver, ssl->min_minor_ver ) ); |
| |
| ssl_send_alert_message( ssl, SSL_ALERT_LEVEL_FATAL, |
| SSL_ALERT_MSG_PROTOCOL_VERSION ); |
| |
| return( POLARSSL_ERR_SSL_BAD_HS_PROTOCOL_VERSION ); |
| } |
| |
| ssl->max_major_ver = buf[4]; |
| ssl->max_minor_ver = buf[5]; |
| |
| memcpy( ssl->handshake->randbytes, buf + 6, 32 ); |
| |
| /* |
| * Check the handshake message length |
| */ |
| if( buf[1] != 0 || n != (unsigned int) 4 + ( ( buf[2] << 8 ) | buf[3] ) ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| /* |
| * Check the session length |
| */ |
| sess_len = buf[38]; |
| |
| if( sess_len > 32 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| ssl->session_negotiate->length = sess_len; |
| memset( ssl->session_negotiate->id, 0, |
| sizeof( ssl->session_negotiate->id ) ); |
| memcpy( ssl->session_negotiate->id, buf + 39, |
| ssl->session_negotiate->length ); |
| |
| /* |
| * Check the ciphersuitelist length |
| */ |
| ciph_len = ( buf[39 + sess_len] << 8 ) |
| | ( buf[40 + sess_len] ); |
| |
| if( ciph_len < 2 || ciph_len > 256 || ( ciph_len % 2 ) != 0 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| /* |
| * Check the compression algorithms length |
| */ |
| comp_len = buf[41 + sess_len + ciph_len]; |
| |
| if( comp_len < 1 || comp_len > 16 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| |
| /* |
| * Check the extension length |
| */ |
| if( n > 42 + sess_len + ciph_len + comp_len ) |
| { |
| ext_len = ( buf[42 + sess_len + ciph_len + comp_len] << 8 ) |
| | ( buf[43 + sess_len + ciph_len + comp_len] ); |
| |
| if( ( ext_len > 0 && ext_len < 4 ) || |
| n != 44 + sess_len + ciph_len + comp_len + ext_len ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client hello message" ) ); |
| SSL_DEBUG_BUF( 3, "Ext", buf + 44 + sess_len + ciph_len + comp_len, ext_len); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| } |
| |
| ssl->session_negotiate->compression = SSL_COMPRESS_NULL; |
| #if defined(POLARSSL_ZLIB_SUPPORT) |
| for( i = 0; i < comp_len; ++i ) |
| { |
| if( buf[42 + sess_len + ciph_len + i] == SSL_COMPRESS_DEFLATE ) |
| { |
| ssl->session_negotiate->compression = SSL_COMPRESS_DEFLATE; |
| break; |
| } |
| } |
| #endif |
| |
| SSL_DEBUG_BUF( 3, "client hello, random bytes", |
| buf + 6, 32 ); |
| SSL_DEBUG_BUF( 3, "client hello, session id", |
| buf + 38, sess_len ); |
| SSL_DEBUG_BUF( 3, "client hello, ciphersuitelist", |
| buf + 41 + sess_len, ciph_len ); |
| SSL_DEBUG_BUF( 3, "client hello, compression", |
| buf + 42 + sess_len + ciph_len, comp_len ); |
| |
| /* |
| * Check for TLS_EMPTY_RENEGOTIATION_INFO_SCSV |
| */ |
| for( i = 0, p = buf + 41 + sess_len; i < ciph_len; i += 2, p += 2 ) |
| { |
| if( p[0] == 0 && p[1] == SSL_EMPTY_RENEGOTIATION_INFO ) |
| { |
| SSL_DEBUG_MSG( 3, ( "received TLS_EMPTY_RENEGOTIATION_INFO " ) ); |
| if( ssl->renegotiation == SSL_RENEGOTIATION ) |
| { |
| SSL_DEBUG_MSG( 1, ( "received RENEGOTIATION SCSV during renegotiation" ) ); |
| |
| if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 ) |
| return( ret ); |
| |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| ssl->secure_renegotiation = SSL_SECURE_RENEGOTIATION; |
| break; |
| } |
| } |
| |
| /* |
| * Search for a matching ciphersuite |
| */ |
| for( i = 0; ssl->ciphersuites[i] != 0; i++ ) |
| { |
| for( j = 0, p = buf + 41 + sess_len; j < ciph_len; |
| j += 2, p += 2 ) |
| { |
| if( p[0] == 0 && p[1] == ssl->ciphersuites[i] ) |
| goto have_ciphersuite; |
| } |
| } |
| |
| SSL_DEBUG_MSG( 1, ( "got no ciphersuites in common" ) ); |
| |
| return( POLARSSL_ERR_SSL_NO_CIPHER_CHOSEN ); |
| |
| have_ciphersuite: |
| ssl->session_negotiate->ciphersuite = ssl->ciphersuites[i]; |
| ssl->transform_negotiate->ciphersuite_info = |
| ssl_ciphersuite_from_id( ssl->ciphersuites[i] ); |
| |
| if( ssl->transform_negotiate->ciphersuite_info == NULL ) |
| { |
| SSL_DEBUG_MSG( 1, ( "ciphersuite info for %02x not found", |
| ssl->ciphersuites[i] ) ); |
| return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); |
| } |
| |
| ssl_optimize_checksum( ssl, ssl->session_negotiate->ciphersuite ); |
| |
| ext = buf + 44 + sess_len + ciph_len + comp_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 client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| } |
| switch( ext_id ) |
| { |
| case TLS_EXT_SERVERNAME: |
| SSL_DEBUG_MSG( 3, ( "found ServerName extension" ) ); |
| if( ssl->f_sni == NULL ) |
| break; |
| |
| ret = ssl_parse_servername_ext( ssl, ext + 4, ext_size ); |
| if( ret != 0 ) |
| return( ret ); |
| break; |
| |
| case TLS_EXT_RENEGOTIATION_INFO: |
| SSL_DEBUG_MSG( 3, ( "found renegotiation extension" ) ); |
| renegotiation_info_seen = 1; |
| |
| ret = ssl_parse_renegotiation_info( ssl, ext + 4, ext_size ); |
| if( ret != 0 ) |
| return( ret ); |
| break; |
| |
| case TLS_EXT_SIG_ALG: |
| SSL_DEBUG_MSG( 3, ( "found signature_algorithms extension" ) ); |
| if( ssl->renegotiation == SSL_RENEGOTIATION ) |
| break; |
| |
| ret = ssl_parse_signature_algorithms_ext( ssl, ext + 4, ext_size ); |
| if( ret != 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 client hello message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_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_CLIENT_HELLO ); |
| } |
| |
| ssl->in_left = 0; |
| ssl->state++; |
| |
| SSL_DEBUG_MSG( 2, ( "<= parse client hello" ) ); |
| |
| return( 0 ); |
| } |
| |
| static int ssl_write_server_hello( ssl_context *ssl ) |
| { |
| time_t t; |
| int ret, n; |
| size_t ext_len = 0; |
| unsigned char *buf, *p; |
| |
| SSL_DEBUG_MSG( 2, ( "=> write server hello" ) ); |
| |
| /* |
| * 0 . 0 handshake type |
| * 1 . 3 handshake length |
| * 4 . 5 protocol version |
| * 6 . 9 UNIX time() |
| * 10 . 37 random bytes |
| */ |
| buf = ssl->out_msg; |
| p = buf + 4; |
| |
| *p++ = (unsigned char) ssl->major_ver; |
| *p++ = (unsigned char) ssl->minor_ver; |
| |
| SSL_DEBUG_MSG( 3, ( "server hello, chosen 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, ( "server hello, current time: %lu", t ) ); |
| |
| if( ( ret = ssl->f_rng( ssl->p_rng, p, 28 ) ) != 0 ) |
| return( ret ); |
| |
| p += 28; |
| |
| memcpy( ssl->handshake->randbytes + 32, buf + 6, 32 ); |
| |
| SSL_DEBUG_BUF( 3, "server hello, random bytes", buf + 6, 32 ); |
| |
| /* |
| * 38 . 38 session id length |
| * 39 . 38+n session id |
| * 39+n . 40+n chosen ciphersuite |
| * 41+n . 41+n chosen compression alg. |
| */ |
| ssl->session_negotiate->length = n = 32; |
| *p++ = (unsigned char) ssl->session_negotiate->length; |
| |
| if( ssl->renegotiation != SSL_INITIAL_HANDSHAKE || |
| ssl->f_get_cache == NULL || |
| ssl->f_get_cache( ssl->p_get_cache, ssl->session_negotiate ) != 0 ) |
| { |
| /* |
| * Not found, create a new session id |
| */ |
| ssl->handshake->resume = 0; |
| ssl->state++; |
| |
| if( ( ret = ssl->f_rng( ssl->p_rng, ssl->session_negotiate->id, |
| n ) ) != 0 ) |
| return( ret ); |
| } |
| else |
| { |
| /* |
| * Found a matching session, resuming it |
| */ |
| ssl->handshake->resume = 1; |
| ssl->state = SSL_SERVER_CHANGE_CIPHER_SPEC; |
| |
| if( ( ret = ssl_derive_keys( ssl ) ) != 0 ) |
| { |
| SSL_DEBUG_RET( 1, "ssl_derive_keys", ret ); |
| return( ret ); |
| } |
| } |
| |
| memcpy( p, ssl->session_negotiate->id, ssl->session_negotiate->length ); |
| p += ssl->session_negotiate->length; |
| |
| SSL_DEBUG_MSG( 3, ( "server hello, session id len.: %d", n ) ); |
| SSL_DEBUG_BUF( 3, "server hello, session id", buf + 39, n ); |
| SSL_DEBUG_MSG( 3, ( "%s session has been resumed", |
| ssl->handshake->resume ? "a" : "no" ) ); |
| |
| *p++ = (unsigned char)( ssl->session_negotiate->ciphersuite >> 8 ); |
| *p++ = (unsigned char)( ssl->session_negotiate->ciphersuite ); |
| *p++ = (unsigned char)( ssl->session_negotiate->compression ); |
| |
| SSL_DEBUG_MSG( 3, ( "server hello, chosen ciphersuite: %d", |
| ssl->session_negotiate->ciphersuite ) ); |
| SSL_DEBUG_MSG( 3, ( "server hello, compress alg.: %d", |
| ssl->session_negotiate->compression ) ); |
| |
| SSL_DEBUG_MSG( 3, ( "server hello, prepping for secure renegotiation extension" ) ); |
| ext_len += 5 + ssl->verify_data_len * 2; |
| |
| SSL_DEBUG_MSG( 3, ( "server hello, total extension length: %d", |
| ext_len ) ); |
| |
| *p++ = (unsigned char)( ( ext_len >> 8 ) & 0xFF ); |
| *p++ = (unsigned char)( ( ext_len ) & 0xFF ); |
| |
| /* |
| * Secure renegotiation |
| */ |
| SSL_DEBUG_MSG( 3, ( "client hello, secure renegotiation 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 * 2 + 1 ) & 0xFF; |
| *p++ = ssl->verify_data_len * 2 & 0xFF; |
| |
| memcpy( p, ssl->peer_verify_data, ssl->verify_data_len ); |
| p += ssl->verify_data_len; |
| memcpy( p, ssl->own_verify_data, ssl->verify_data_len ); |
| p += ssl->verify_data_len; |
| |
| ssl->out_msglen = p - buf; |
| ssl->out_msgtype = SSL_MSG_HANDSHAKE; |
| ssl->out_msg[0] = SSL_HS_SERVER_HELLO; |
| |
| ret = ssl_write_record( ssl ); |
| |
| SSL_DEBUG_MSG( 2, ( "<= write server hello" ) ); |
| |
| return( ret ); |
| } |
| |
| static int ssl_write_certificate_request( ssl_context *ssl ) |
| { |
| int ret; |
| size_t n = 0, dn_size, total_dn_size; |
| unsigned char *buf, *p; |
| const x509_cert *crt; |
| |
| SSL_DEBUG_MSG( 2, ( "=> write certificate request" ) ); |
| |
| ssl->state++; |
| |
| if( ssl->authmode == SSL_VERIFY_NONE ) |
| { |
| SSL_DEBUG_MSG( 2, ( "<= skip write certificate request" ) ); |
| 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. |
| */ |
| buf = ssl->out_msg; |
| p = buf + 4; |
| |
| /* |
| * At the moment, only RSA certificates are supported |
| */ |
| *p++ = 1; |
| *p++ = SSL_CERT_TYPE_RSA_SIGN; |
| |
| /* |
| * Add signature_algorithms for verify (TLS 1.2) |
| * Only add current running algorithm that is already required for |
| * requested ciphersuite. |
| * |
| * Length is always 2 |
| */ |
| if( ssl->minor_ver == SSL_MINOR_VERSION_3 ) |
| { |
| ssl->handshake->verify_sig_alg = SSL_HASH_SHA256; |
| |
| *p++ = 0; |
| *p++ = 2; |
| |
| if( ssl->session_negotiate->ciphersuite == TLS_RSA_WITH_AES_256_GCM_SHA384 || |
| ssl->session_negotiate->ciphersuite == TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 ) |
| { |
| ssl->handshake->verify_sig_alg = SSL_HASH_SHA384; |
| } |
| |
| *p++ = ssl->handshake->verify_sig_alg; |
| *p++ = SSL_SIG_RSA; |
| |
| n += 4; |
| } |
| |
| p += 2; |
| crt = ssl->ca_chain; |
| |
| total_dn_size = 0; |
| while( crt != NULL ) |
| { |
| if( p - buf > 4096 ) |
| break; |
| |
| dn_size = crt->subject_raw.len; |
| *p++ = (unsigned char)( dn_size >> 8 ); |
| *p++ = (unsigned char)( dn_size ); |
| memcpy( p, crt->subject_raw.p, dn_size ); |
| p += dn_size; |
| |
| SSL_DEBUG_BUF( 3, "requested DN", p, dn_size ); |
| |
| total_dn_size += 2 + dn_size; |
| crt = crt->next; |
| } |
| |
| ssl->out_msglen = p - buf; |
| ssl->out_msgtype = SSL_MSG_HANDSHAKE; |
| ssl->out_msg[0] = SSL_HS_CERTIFICATE_REQUEST; |
| ssl->out_msg[6 + n] = (unsigned char)( total_dn_size >> 8 ); |
| ssl->out_msg[7 + n] = (unsigned char)( total_dn_size ); |
| |
| ret = ssl_write_record( ssl ); |
| |
| SSL_DEBUG_MSG( 2, ( "<= write certificate request" ) ); |
| |
| return( ret ); |
| } |
| |
| static int ssl_write_server_key_exchange( ssl_context *ssl ) |
| { |
| #if defined(POLARSSL_DHM_C) |
| int ret; |
| size_t n, rsa_key_len = 0; |
| unsigned char hash[64]; |
| int hash_id = 0; |
| unsigned int hashlen = 0; |
| #endif |
| |
| SSL_DEBUG_MSG( 2, ( "=> write server key exchange" ) ); |
| |
| if( ssl->transform_negotiate->ciphersuite_info->key_exchange != |
| POLARSSL_KEY_EXCHANGE_DHE_RSA ) |
| { |
| SSL_DEBUG_MSG( 2, ( "<= skip write server key exchange" ) ); |
| ssl->state++; |
| return( 0 ); |
| } |
| |
| #if !defined(POLARSSL_DHM_C) |
| SSL_DEBUG_MSG( 1, ( "support for dhm is not available" ) ); |
| return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE ); |
| #else |
| |
| if( ssl->rsa_key == NULL ) |
| { |
| SSL_DEBUG_MSG( 1, ( "got no private key" ) ); |
| return( POLARSSL_ERR_SSL_PRIVATE_KEY_REQUIRED ); |
| } |
| |
| /* |
| * 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 = mpi_copy( &ssl->handshake->dhm_ctx.P, &ssl->dhm_P ) ) != 0 || |
| ( ret = mpi_copy( &ssl->handshake->dhm_ctx.G, &ssl->dhm_G ) ) != 0 ) |
| { |
| SSL_DEBUG_RET( 1, "mpi_copy", ret ); |
| return( ret ); |
| } |
| |
| if( ( ret = dhm_make_params( &ssl->handshake->dhm_ctx, |
| mpi_size( &ssl->handshake->dhm_ctx.P ), |
| ssl->out_msg + 4, |
| &n, ssl->f_rng, ssl->p_rng ) ) != 0 ) |
| { |
| SSL_DEBUG_RET( 1, "dhm_make_params", ret ); |
| return( ret ); |
| } |
| |
| SSL_DEBUG_MPI( 3, "DHM: X ", &ssl->handshake->dhm_ctx.X ); |
| 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: GX", &ssl->handshake->dhm_ctx.GX ); |
| |
| if( ssl->minor_ver != SSL_MINOR_VERSION_3 ) |
| { |
| md5_context md5; |
| sha1_context sha1; |
| |
| /* |
| * 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->out_msg + 4, n ); |
| md5_finish( &md5, hash ); |
| |
| sha1_starts( &sha1 ); |
| sha1_update( &sha1, ssl->handshake->randbytes, 64 ); |
| sha1_update( &sha1, ssl->out_msg + 4, n ); |
| sha1_finish( &sha1, hash + 16 ); |
| |
| hashlen = 36; |
| hash_id = SIG_RSA_RAW; |
| } |
| else |
| { |
| /* |
| * digitally-signed struct { |
| * opaque client_random[32]; |
| * opaque server_random[32]; |
| * ServerDHParams params; |
| * }; |
| */ |
| #if defined(POLARSSL_SHA4_C) |
| if( ssl->handshake->sig_alg == SSL_HASH_SHA512 ) |
| { |
| sha4_context sha4; |
| |
| sha4_starts( &sha4, 0 ); |
| sha4_update( &sha4, ssl->handshake->randbytes, 64 ); |
| sha4_update( &sha4, ssl->out_msg + 4, n ); |
| sha4_finish( &sha4, hash ); |
| |
| hashlen = 64; |
| hash_id = SIG_RSA_SHA512; |
| } |
| else if( ssl->handshake->sig_alg == SSL_HASH_SHA384 ) |
| { |
| sha4_context sha4; |
| |
| sha4_starts( &sha4, 1 ); |
| sha4_update( &sha4, ssl->handshake->randbytes, 64 ); |
| sha4_update( &sha4, ssl->out_msg + 4, n ); |
| sha4_finish( &sha4, hash ); |
| |
| hashlen = 48; |
| hash_id = SIG_RSA_SHA384; |
| } |
| else |
| #endif |
| #if defined(POLARSSL_SHA2_C) |
| if( ssl->handshake->sig_alg == SSL_HASH_SHA256 ) |
| { |
| sha2_context sha2; |
| |
| sha2_starts( &sha2, 0 ); |
| sha2_update( &sha2, ssl->handshake->randbytes, 64 ); |
| sha2_update( &sha2, ssl->out_msg + 4, n ); |
| sha2_finish( &sha2, hash ); |
| |
| hashlen = 32; |
| hash_id = SIG_RSA_SHA256; |
| } |
| else if( ssl->handshake->sig_alg == SSL_HASH_SHA224 ) |
| { |
| sha2_context sha2; |
| |
| sha2_starts( &sha2, 1 ); |
| sha2_update( &sha2, ssl->handshake->randbytes, 64 ); |
| sha2_update( &sha2, ssl->out_msg + 4, n ); |
| sha2_finish( &sha2, hash ); |
| |
| hashlen = 24; |
| hash_id = SIG_RSA_SHA224; |
| } |
| else |
| #endif |
| if( ssl->handshake->sig_alg == SSL_HASH_SHA1 ) |
| { |
| sha1_context sha1; |
| |
| sha1_starts( &sha1 ); |
| sha1_update( &sha1, ssl->handshake->randbytes, 64 ); |
| sha1_update( &sha1, ssl->out_msg + 4, n ); |
| sha1_finish( &sha1, hash ); |
| |
| hashlen = 20; |
| hash_id = SIG_RSA_SHA1; |
| } |
| else if( ssl->handshake->sig_alg == SSL_HASH_MD5 ) |
| { |
| md5_context md5; |
| |
| md5_starts( &md5 ); |
| md5_update( &md5, ssl->handshake->randbytes, 64 ); |
| md5_update( &md5, ssl->out_msg + 4, n ); |
| md5_finish( &md5, hash ); |
| |
| hashlen = 16; |
| hash_id = SIG_RSA_MD5; |
| } |
| } |
| |
| SSL_DEBUG_BUF( 3, "parameters hash", hash, hashlen ); |
| |
| if ( ssl->rsa_key ) |
| rsa_key_len = ssl->rsa_key_len( ssl->rsa_key ); |
| |
| if( ssl->minor_ver == SSL_MINOR_VERSION_3 ) |
| { |
| ssl->out_msg[4 + n] = ssl->handshake->sig_alg; |
| ssl->out_msg[5 + n] = SSL_SIG_RSA; |
| |
| n += 2; |
| } |
| |
| ssl->out_msg[4 + n] = (unsigned char)( rsa_key_len >> 8 ); |
| ssl->out_msg[5 + n] = (unsigned char)( rsa_key_len ); |
| |
| 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 + n ); |
| } |
| |
| if( ret != 0 ) |
| { |
| SSL_DEBUG_RET( 1, "pkcs1_sign", ret ); |
| return( ret ); |
| } |
| |
| SSL_DEBUG_BUF( 3, "my RSA sig", ssl->out_msg + 6 + n, rsa_key_len ); |
| |
| ssl->out_msglen = 6 + n + rsa_key_len; |
| ssl->out_msgtype = SSL_MSG_HANDSHAKE; |
| ssl->out_msg[0] = SSL_HS_SERVER_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 server key exchange" ) ); |
| |
| return( 0 ); |
| #endif |
| } |
| |
| static int ssl_write_server_hello_done( ssl_context *ssl ) |
| { |
| int ret; |
| |
| SSL_DEBUG_MSG( 2, ( "=> write server hello done" ) ); |
| |
| ssl->out_msglen = 4; |
| ssl->out_msgtype = SSL_MSG_HANDSHAKE; |
| ssl->out_msg[0] = SSL_HS_SERVER_HELLO_DONE; |
| |
| ssl->state++; |
| |
| if( ( ret = ssl_write_record( ssl ) ) != 0 ) |
| { |
| SSL_DEBUG_RET( 1, "ssl_write_record", ret ); |
| return( ret ); |
| } |
| |
| SSL_DEBUG_MSG( 2, ( "<= write server hello done" ) ); |
| |
| return( 0 ); |
| } |
| |
| static int ssl_parse_client_key_exchange( ssl_context *ssl ) |
| { |
| int ret; |
| size_t i, n = 0; |
| |
| SSL_DEBUG_MSG( 2, ( "=> parse client key exchange" ) ); |
| |
| 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 client key exchange message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE ); |
| } |
| |
| if( ssl->in_msg[0] != SSL_HS_CLIENT_KEY_EXCHANGE ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE ); |
| } |
| |
| if( ssl->transform_negotiate->ciphersuite_info->key_exchange == |
| POLARSSL_KEY_EXCHANGE_DHE_RSA ) |
| { |
| #if !defined(POLARSSL_DHM_C) |
| SSL_DEBUG_MSG( 1, ( "support for dhm is not available" ) ); |
| return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE ); |
| #else |
| /* |
| * Receive G^Y mod P, premaster = (G^Y)^X mod P |
| */ |
| n = ( ssl->in_msg[4] << 8 ) | ssl->in_msg[5]; |
| |
| if( n < 1 || n > ssl->handshake->dhm_ctx.len || |
| n + 6 != ssl->in_hslen ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE ); |
| } |
| |
| if( ( ret = dhm_read_public( &ssl->handshake->dhm_ctx, |
| ssl->in_msg + 6, n ) ) != 0 ) |
| { |
| SSL_DEBUG_RET( 1, "dhm_read_public", ret ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_DHM_RP ); |
| } |
| |
| SSL_DEBUG_MPI( 3, "DHM: GY", &ssl->handshake->dhm_ctx.GY ); |
| |
| 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( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_DHM_CS ); |
| } |
| |
| SSL_DEBUG_MPI( 3, "DHM: K ", &ssl->handshake->dhm_ctx.K ); |
| #endif |
| } |
| else |
| { |
| if( ssl->rsa_key == NULL ) |
| { |
| SSL_DEBUG_MSG( 1, ( "got no private key" ) ); |
| return( POLARSSL_ERR_SSL_PRIVATE_KEY_REQUIRED ); |
| } |
| |
| /* |
| * Decrypt the premaster using own private RSA key |
| */ |
| i = 4; |
| if( ssl->rsa_key ) |
| n = ssl->rsa_key_len( ssl->rsa_key ); |
| ssl->handshake->pmslen = 48; |
| |
| if( ssl->minor_ver != SSL_MINOR_VERSION_0 ) |
| { |
| i += 2; |
| if( ssl->in_msg[4] != ( ( n >> 8 ) & 0xFF ) || |
| ssl->in_msg[5] != ( ( n ) & 0xFF ) ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE ); |
| } |
| } |
| |
| if( ssl->in_hslen != i + n ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE ); |
| } |
| |
| if( ssl->rsa_key ) { |
| ret = ssl->rsa_decrypt( ssl->rsa_key, RSA_PRIVATE, |
| &ssl->handshake->pmslen, |
| ssl->in_msg + i, |
| ssl->handshake->premaster, |
| sizeof(ssl->handshake->premaster) ); |
| } |
| |
| if( ret != 0 || ssl->handshake->pmslen != 48 || |
| ssl->handshake->premaster[0] != ssl->max_major_ver || |
| ssl->handshake->premaster[1] != ssl->max_minor_ver ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) ); |
| |
| /* |
| * Protection against Bleichenbacher's attack: |
| * invalid PKCS#1 v1.5 padding must not cause |
| * the connection to end immediately; instead, |
| * send a bad_record_mac later in the handshake. |
| */ |
| ssl->handshake->pmslen = 48; |
| |
| ret = ssl->f_rng( ssl->p_rng, ssl->handshake->premaster, |
| ssl->handshake->pmslen ); |
| if( ret != 0 ) |
| return( ret ); |
| } |
| } |
| |
| if( ( ret = ssl_derive_keys( ssl ) ) != 0 ) |
| { |
| SSL_DEBUG_RET( 1, "ssl_derive_keys", ret ); |
| return( ret ); |
| } |
| |
| ssl->state++; |
| |
| SSL_DEBUG_MSG( 2, ( "<= parse client key exchange" ) ); |
| |
| return( 0 ); |
| } |
| |
| static int ssl_parse_certificate_verify( ssl_context *ssl ) |
| { |
| int ret; |
| size_t n = 0, n1, n2; |
| unsigned char hash[48]; |
| int hash_id; |
| unsigned int hashlen; |
| |
| SSL_DEBUG_MSG( 2, ( "=> parse certificate verify" ) ); |
| |
| if( ssl->session_negotiate->peer_cert == NULL ) |
| { |
| SSL_DEBUG_MSG( 2, ( "<= skip parse certificate verify" ) ); |
| ssl->state++; |
| return( 0 ); |
| } |
| |
| ssl->handshake->calc_verify( ssl, hash ); |
| |
| if( ( ret = ssl_read_record( ssl ) ) != 0 ) |
| { |
| SSL_DEBUG_RET( 1, "ssl_read_record", ret ); |
| return( ret ); |
| } |
| |
| ssl->state++; |
| |
| if( ssl->in_msgtype != SSL_MSG_HANDSHAKE ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad certificate verify message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY ); |
| } |
| |
| if( ssl->in_msg[0] != SSL_HS_CERTIFICATE_VERIFY ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad certificate verify message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY ); |
| } |
| |
| if( ssl->minor_ver == SSL_MINOR_VERSION_3 ) |
| { |
| /* |
| * As server we know we either have SSL_HASH_SHA384 or |
| * SSL_HASH_SHA256 |
| */ |
| if( ssl->in_msg[4] != ssl->handshake->verify_sig_alg || |
| ssl->in_msg[5] != SSL_SIG_RSA ) |
| { |
| SSL_DEBUG_MSG( 1, ( "peer not adhering to requested sig_alg for verify message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY ); |
| } |
| |
| if( ssl->handshake->verify_sig_alg == SSL_HASH_SHA384 ) |
| { |
| hashlen = 48; |
| hash_id = SIG_RSA_SHA384; |
| } |
| else |
| { |
| hashlen = 32; |
| hash_id = SIG_RSA_SHA256; |
| } |
| |
| n += 2; |
| } |
| else |
| { |
| hashlen = 36; |
| hash_id = SIG_RSA_RAW; |
| } |
| |
| n1 = ssl->session_negotiate->peer_cert->rsa.len; |
| n2 = ( ssl->in_msg[4 + n] << 8 ) | ssl->in_msg[5 + n]; |
| |
| if( n + n1 + 6 != ssl->in_hslen || n1 != n2 ) |
| { |
| SSL_DEBUG_MSG( 1, ( "bad certificate verify message" ) ); |
| return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY ); |
| } |
| |
| ret = rsa_pkcs1_verify( &ssl->session_negotiate->peer_cert->rsa, RSA_PUBLIC, |
| hash_id, hashlen, hash, ssl->in_msg + 6 + n ); |
| if( ret != 0 ) |
| { |
| SSL_DEBUG_RET( 1, "rsa_pkcs1_verify", ret ); |
| return( ret ); |
| } |
| |
| SSL_DEBUG_MSG( 2, ( "<= parse certificate verify" ) ); |
| |
| return( 0 ); |
| } |
| |
| /* |
| * SSL handshake -- server side -- single step |
| */ |
| int ssl_handshake_server_step( ssl_context *ssl ) |
| { |
| int ret = 0; |
| |
| if( ssl->state == SSL_HANDSHAKE_OVER ) |
| return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); |
| |
| SSL_DEBUG_MSG( 2, ( "server 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_parse_client_hello( ssl ); |
| break; |
| |
| /* |
| * ==> ServerHello |
| * Certificate |
| * ( ServerKeyExchange ) |
| * ( CertificateRequest ) |
| * ServerHelloDone |
| */ |
| case SSL_SERVER_HELLO: |
| ret = ssl_write_server_hello( ssl ); |
| break; |
| |
| case SSL_SERVER_CERTIFICATE: |
| ret = ssl_write_certificate( ssl ); |
| break; |
| |
| case SSL_SERVER_KEY_EXCHANGE: |
| ret = ssl_write_server_key_exchange( ssl ); |
| break; |
| |
| case SSL_CERTIFICATE_REQUEST: |
| ret = ssl_write_certificate_request( ssl ); |
| break; |
| |
| case SSL_SERVER_HELLO_DONE: |
| ret = ssl_write_server_hello_done( ssl ); |
| break; |
| |
| /* |
| * <== ( Certificate/Alert ) |
| * ClientKeyExchange |
| * ( CertificateVerify ) |
| * ChangeCipherSpec |
| * Finished |
| */ |
| case SSL_CLIENT_CERTIFICATE: |
| ret = ssl_parse_certificate( ssl ); |
| break; |
| |
| case SSL_CLIENT_KEY_EXCHANGE: |
| ret = ssl_parse_client_key_exchange( ssl ); |
| break; |
| |
| case SSL_CERTIFICATE_VERIFY: |
| ret = ssl_parse_certificate_verify( ssl ); |
| break; |
| |
| case SSL_CLIENT_CHANGE_CIPHER_SPEC: |
| ret = ssl_parse_change_cipher_spec( ssl ); |
| break; |
| |
| case SSL_CLIENT_FINISHED: |
| ret = ssl_parse_finished( ssl ); |
| break; |
| |
| /* |
| * ==> ChangeCipherSpec |
| * Finished |
| */ |
| case SSL_SERVER_CHANGE_CIPHER_SPEC: |
| ret = ssl_write_change_cipher_spec( ssl ); |
| break; |
| |
| case SSL_SERVER_FINISHED: |
| ret = ssl_write_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 |