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[ssl->minor_ver][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[ssl->minor_ver][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[ssl->minor_ver][i];
    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_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] ) );

     
    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_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] ) );

     
    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 );

     
    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 );
    }

     
    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 );

     
    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 );
    }

     
    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 );
    }

     
    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 );

     
    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;
        }
    }

     
    for( i = 0; ssl->ciphersuites[ssl->minor_ver][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[ssl->minor_ver][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[ssl->minor_ver][i];
    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 );
        }
    }

     
    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 );
}