- Removed handling for SSLv2 Client Hello (as per RFC 5246 recommendation)
This commit is contained in:
Paul Bakker
parent
68b6d88f5e
commit
ec636f3bdd
@ -35,6 +35,7 @@ Changes
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to not match CN if subjectAltName extension is present (Closes ticket #56)
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* Cipher layer cipher_mode_t POLARSSL_MODE_CFB128 is renamed to
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POLARSSL_MODE_CFB, to also handle different block size CFB modes.
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* Removed handling for SSLv2 Client Hello (as per RFC 5246 recommendation)
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Bugfix
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* Fixed handling error in mpi_cmp_mpi() on longer B values (found by
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@ -44,7 +44,7 @@ static int ssl_parse_client_hello( ssl_context *ssl )
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unsigned int i, j;
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size_t n;
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unsigned int ciph_len, sess_len;
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unsigned int chal_len, comp_len;
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unsigned int comp_len;
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unsigned char *buf, *p;
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SSL_DEBUG_MSG( 2, ( "=> parse client hello" ) );
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@ -57,297 +57,169 @@ static int ssl_parse_client_hello( ssl_context *ssl )
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buf = ssl->in_hdr;
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if( ( buf[0] & 0x80 ) != 0 )
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SSL_DEBUG_BUF( 4, "record header", buf, 5 );
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SSL_DEBUG_MSG( 3, ( "client hello v3, message type: %d",
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buf[0] ) );
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SSL_DEBUG_MSG( 3, ( "client hello v3, message len.: %d",
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( buf[3] << 8 ) | buf[4] ) );
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SSL_DEBUG_MSG( 3, ( "client hello v3, protocol ver: [%d:%d]",
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buf[1], buf[2] ) );
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/*
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* SSLv3 Client Hello
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*
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* Record layer:
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* 0 . 0 message type
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* 1 . 2 protocol version
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* 3 . 4 message length
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*/
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if( buf[0] != SSL_MSG_HANDSHAKE ||
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buf[1] != SSL_MAJOR_VERSION_3 )
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{
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SSL_DEBUG_BUF( 4, "record header", buf, 5 );
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SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
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return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
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}
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SSL_DEBUG_MSG( 3, ( "client hello v2, message type: %d",
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buf[2] ) );
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SSL_DEBUG_MSG( 3, ( "client hello v2, message len.: %d",
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( ( buf[0] & 0x7F ) << 8 ) | buf[1] ) );
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SSL_DEBUG_MSG( 3, ( "client hello v2, max. version: [%d:%d]",
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buf[3], buf[4] ) );
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n = ( buf[3] << 8 ) | buf[4];
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/*
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* SSLv2 Client Hello
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*
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* Record layer:
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* 0 . 1 message length
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*
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* SSL layer:
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* 2 . 2 message type
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* 3 . 4 protocol version
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*/
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if( buf[2] != SSL_HS_CLIENT_HELLO ||
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buf[3] != SSL_MAJOR_VERSION_3 )
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if( n < 45 || n > 512 )
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{
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SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
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return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
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}
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if( ( ret = ssl_fetch_input( ssl, 5 + n ) ) != 0 )
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{
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SSL_DEBUG_RET( 1, "ssl_fetch_input", ret );
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return( ret );
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}
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buf = ssl->in_msg;
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n = ssl->in_left - 5;
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ssl->update_checksum( ssl, buf, n );
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/*
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* SSL layer:
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* 0 . 0 handshake type
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* 1 . 3 handshake length
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* 4 . 5 protocol version
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* 6 . 9 UNIX time()
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* 10 . 37 random bytes
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* 38 . 38 session id length
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* 39 . 38+x session id
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* 39+x . 40+x ciphersuitelist length
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* 41+x . .. ciphersuitelist
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* .. . .. compression alg.
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* .. . .. extensions
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*/
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SSL_DEBUG_BUF( 4, "record contents", buf, n );
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SSL_DEBUG_MSG( 3, ( "client hello v3, handshake type: %d",
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buf[0] ) );
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SSL_DEBUG_MSG( 3, ( "client hello v3, handshake len.: %d",
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( buf[1] << 16 ) | ( buf[2] << 8 ) | buf[3] ) );
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SSL_DEBUG_MSG( 3, ( "client hello v3, max. version: [%d:%d]",
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buf[4], buf[5] ) );
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/*
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* Check the handshake type and protocol version
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*/
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if( buf[0] != SSL_HS_CLIENT_HELLO ||
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buf[4] != SSL_MAJOR_VERSION_3 )
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{
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SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
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return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
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}
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ssl->major_ver = SSL_MAJOR_VERSION_3;
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ssl->minor_ver = ( buf[5] <= SSL_MINOR_VERSION_3 )
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? buf[5] : SSL_MINOR_VERSION_3;
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ssl->max_major_ver = buf[4];
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ssl->max_minor_ver = buf[5];
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memcpy( ssl->randbytes, buf + 6, 32 );
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/*
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* Check the handshake message length
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*/
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if( buf[1] != 0 || n != (unsigned int) 4 + ( ( buf[2] << 8 ) | buf[3] ) )
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{
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SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
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return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
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}
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/*
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* Check the session length
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*/
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sess_len = buf[38];
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if( sess_len > 32 )
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{
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SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
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return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
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}
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ssl->session->length = sess_len;
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memset( ssl->session->id, 0, sizeof( ssl->session->id ) );
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memcpy( ssl->session->id, buf + 39 , ssl->session->length );
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/*
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* Check the ciphersuitelist length
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*/
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ciph_len = ( buf[39 + sess_len] << 8 )
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| ( buf[40 + sess_len] );
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if( ciph_len < 2 || ciph_len > 256 || ( ciph_len % 2 ) != 0 )
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{
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SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
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return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
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}
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/*
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* Check the compression algorithms length
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*/
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comp_len = buf[41 + sess_len + ciph_len];
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if( comp_len < 1 || comp_len > 16 )
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{
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SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
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return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
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}
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ssl->session->compression = SSL_COMPRESS_NULL;
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#if defined(POLARSSL_ZLIB_SUPPORT)
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for( i = 0; i < comp_len; ++i )
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{
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if( buf[41 + sess_len + ciph_len + i] == SSL_COMPRESS_DEFLATE )
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{
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SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
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return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
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}
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n = ( ( buf[0] << 8 ) | buf[1] ) & 0x7FFF;
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if( n < 17 || n > 512 )
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{
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SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
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return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
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}
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ssl->max_major_ver = buf[3];
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ssl->max_minor_ver = buf[4];
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ssl->major_ver = SSL_MAJOR_VERSION_3;
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ssl->minor_ver = ( buf[4] <= SSL_MINOR_VERSION_3 )
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? buf[4] : SSL_MINOR_VERSION_3;
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if( ( ret = ssl_fetch_input( ssl, 2 + n ) ) != 0 )
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{
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SSL_DEBUG_RET( 1, "ssl_fetch_input", ret );
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return( ret );
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}
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ssl->update_checksum( ssl, buf + 2, n );
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buf = ssl->in_msg;
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n = ssl->in_left - 5;
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/*
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* 0 . 1 ciphersuitelist length
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* 2 . 3 session id length
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* 4 . 5 challenge length
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* 6 . .. ciphersuitelist
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* .. . .. session id
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* .. . .. challenge
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*/
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SSL_DEBUG_BUF( 4, "record contents", buf, n );
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ciph_len = ( buf[0] << 8 ) | buf[1];
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sess_len = ( buf[2] << 8 ) | buf[3];
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chal_len = ( buf[4] << 8 ) | buf[5];
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SSL_DEBUG_MSG( 3, ( "ciph_len: %d, sess_len: %d, chal_len: %d",
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ciph_len, sess_len, chal_len ) );
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/*
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* Make sure each parameter length is valid
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*/
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if( ciph_len < 3 || ( ciph_len % 3 ) != 0 )
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{
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SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
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return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
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}
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if( sess_len > 32 )
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{
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SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
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return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
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}
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if( chal_len < 8 || chal_len > 32 )
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{
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SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
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return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
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}
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if( n != 6 + ciph_len + sess_len + chal_len )
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{
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SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
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return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
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}
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SSL_DEBUG_BUF( 3, "client hello, ciphersuitelist",
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buf + 6, ciph_len );
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SSL_DEBUG_BUF( 3, "client hello, session id",
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buf + 6 + ciph_len, sess_len );
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SSL_DEBUG_BUF( 3, "client hello, challenge",
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buf + 6 + ciph_len + sess_len, chal_len );
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p = buf + 6 + ciph_len;
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ssl->session->length = sess_len;
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memset( ssl->session->id, 0, sizeof( ssl->session->id ) );
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memcpy( ssl->session->id, p, ssl->session->length );
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p += sess_len;
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memset( ssl->randbytes, 0, 64 );
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memcpy( ssl->randbytes + 32 - chal_len, p, chal_len );
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for( i = 0; ssl->ciphersuites[i] != 0; i++ )
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{
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for( j = 0, p = buf + 6; j < ciph_len; j += 3, p += 3 )
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{
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if( p[0] == 0 &&
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p[1] == 0 &&
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p[2] == ssl->ciphersuites[i] )
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goto have_ciphersuite;
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}
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ssl->session->compression = SSL_COMPRESS_DEFLATE;
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break;
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}
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}
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else
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{
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SSL_DEBUG_BUF( 4, "record header", buf, 5 );
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SSL_DEBUG_MSG( 3, ( "client hello v3, message type: %d",
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buf[0] ) );
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SSL_DEBUG_MSG( 3, ( "client hello v3, message len.: %d",
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( buf[3] << 8 ) | buf[4] ) );
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SSL_DEBUG_MSG( 3, ( "client hello v3, protocol ver: [%d:%d]",
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buf[1], buf[2] ) );
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/*
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* SSLv3 Client Hello
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*
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* Record layer:
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* 0 . 0 message type
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* 1 . 2 protocol version
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* 3 . 4 message length
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*/
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if( buf[0] != SSL_MSG_HANDSHAKE ||
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buf[1] != SSL_MAJOR_VERSION_3 )
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{
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SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
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return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
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}
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n = ( buf[3] << 8 ) | buf[4];
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if( n < 45 || n > 512 )
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{
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SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
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return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
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}
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if( ( ret = ssl_fetch_input( ssl, 5 + n ) ) != 0 )
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{
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SSL_DEBUG_RET( 1, "ssl_fetch_input", ret );
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return( ret );
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}
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buf = ssl->in_msg;
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n = ssl->in_left - 5;
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ssl->update_checksum( ssl, buf, n );
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/*
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* SSL layer:
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* 0 . 0 handshake type
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* 1 . 3 handshake length
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* 4 . 5 protocol version
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* 6 . 9 UNIX time()
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* 10 . 37 random bytes
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* 38 . 38 session id length
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* 39 . 38+x session id
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* 39+x . 40+x ciphersuitelist length
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* 41+x . .. ciphersuitelist
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* .. . .. compression alg.
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* .. . .. extensions
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*/
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SSL_DEBUG_BUF( 4, "record contents", buf, n );
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SSL_DEBUG_MSG( 3, ( "client hello v3, handshake type: %d",
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buf[0] ) );
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SSL_DEBUG_MSG( 3, ( "client hello v3, handshake len.: %d",
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( buf[1] << 16 ) | ( buf[2] << 8 ) | buf[3] ) );
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SSL_DEBUG_MSG( 3, ( "client hello v3, max. version: [%d:%d]",
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buf[4], buf[5] ) );
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/*
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* Check the handshake type and protocol version
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*/
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if( buf[0] != SSL_HS_CLIENT_HELLO ||
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buf[4] != SSL_MAJOR_VERSION_3 )
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{
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SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
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return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
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}
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ssl->major_ver = SSL_MAJOR_VERSION_3;
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ssl->minor_ver = ( buf[5] <= SSL_MINOR_VERSION_3 )
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? buf[5] : SSL_MINOR_VERSION_3;
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ssl->max_major_ver = buf[4];
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ssl->max_minor_ver = buf[5];
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memcpy( ssl->randbytes, buf + 6, 32 );
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/*
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* Check the handshake message length
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*/
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if( buf[1] != 0 || n != (unsigned int) 4 + ( ( buf[2] << 8 ) | buf[3] ) )
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{
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SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
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return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
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}
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/*
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* Check the session length
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*/
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sess_len = buf[38];
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if( sess_len > 32 )
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{
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SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
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return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
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}
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ssl->session->length = sess_len;
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memset( ssl->session->id, 0, sizeof( ssl->session->id ) );
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memcpy( ssl->session->id, buf + 39 , ssl->session->length );
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/*
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* Check the ciphersuitelist length
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*/
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ciph_len = ( buf[39 + sess_len] << 8 )
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| ( buf[40 + sess_len] );
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if( ciph_len < 2 || ciph_len > 256 || ( ciph_len % 2 ) != 0 )
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{
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SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
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return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
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}
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/*
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* Check the compression algorithms length
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*/
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comp_len = buf[41 + sess_len + ciph_len];
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if( comp_len < 1 || comp_len > 16 )
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{
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SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
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return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
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}
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ssl->session->compression = SSL_COMPRESS_NULL;
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#if defined(POLARSSL_ZLIB_SUPPORT)
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for( i = 0; i < comp_len; ++i )
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{
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if( buf[41 + sess_len + ciph_len + i] == SSL_COMPRESS_DEFLATE )
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{
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ssl->session->compression = SSL_COMPRESS_DEFLATE;
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break;
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}
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}
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#endif
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SSL_DEBUG_BUF( 3, "client hello, random bytes",
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buf + 6, 32 );
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SSL_DEBUG_BUF( 3, "client hello, session id",
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buf + 38, sess_len );
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SSL_DEBUG_BUF( 3, "client hello, ciphersuitelist",
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buf + 41 + sess_len, ciph_len );
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SSL_DEBUG_BUF( 3, "client hello, compression",
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buf + 42 + sess_len + ciph_len, comp_len );
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SSL_DEBUG_BUF( 3, "client hello, random bytes",
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buf + 6, 32 );
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SSL_DEBUG_BUF( 3, "client hello, session id",
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buf + 38, sess_len );
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SSL_DEBUG_BUF( 3, "client hello, ciphersuitelist",
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buf + 41 + sess_len, ciph_len );
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SSL_DEBUG_BUF( 3, "client hello, compression",
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buf + 42 + sess_len + ciph_len, comp_len );
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/*
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* Search for a matching ciphersuite
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*/
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for( i = 0; ssl->ciphersuites[i] != 0; i++ )
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/*
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* Search for a matching ciphersuite
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*/
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for( i = 0; ssl->ciphersuites[i] != 0; i++ )
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{
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for( j = 0, p = buf + 41 + sess_len; j < ciph_len;
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j += 2, p += 2 )
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||||
{
|
||||
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;
|
||||
}
|
||||
if( p[0] == 0 && p[1] == ssl->ciphersuites[i] )
|
||||
goto have_ciphersuite;
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user