Is there someone here good at nulling scripts?

here is license.php file how i can null it?

<?


function get_key ()
{
global $keyfile;
$data = @file ($keyfile);
if (!$data)
{
return false;
}

$buffer = false;
foreach ($data as $line)
{
$buffer .= $line;
}

if (!$buffer)
{
return false;
}

$buffer = @str_replace ('<?PHP', '', $buffer);
$buffer = @str_replace ('?>', '', $buffer);
$buffer = @str_replace ('/*--', '', $buffer);
$buffer = @str_replace ('--*/', '', $buffer);
return @str_replace ('
', '', $buffer);
}

function parse_local_key ()
{
global $keyfile;
if (!@file_exists ($keyfile))
{
return false;
}

$raw_data = @base64_decode (@get_key ());
$raw_array = @explode ('|', $raw_data);
if ((@is_array ($raw_array) AND @count ($raw_array) < 8))
{
return false;
}

return $raw_array;
}

function validate_local_key ($array)
{
$raw_array = parse_local_key ();
if ((!@is_array ($raw_array) OR $raw_array === false))
{
return '<verify status='invalid_key' message='No file found or invalid file. Please contact support for a new license key.' />';
}

if (($raw_array[9] AND strcmp (@md5 ('f707118e3a066ae2b7966afcf9f66a14' . $raw_array[9]), $raw_array[10]) != 0))
{
return '<verify status='invalid_key' message='Please contact support for a new license key.' />';
}

if (strcmp (@md5 ('f707118e3a066ae2b7966afcf9f66a14' . $raw_array[1]), $raw_array[2]) != 0)
{
return '<verify status='invalid_key' message='Please contact support for a new license key.' ' . $raw_array[9] . ' />';
}

if (($raw_array[1] < time () AND $raw_array[1] != 'never'))
{
return '<verify status='invalid_key' message='Your local license key has expired. Please contact support for a new license key.' ' . $raw_array[9] . ' />';
}

if ($array['per_server'])
{
$server = phpaudit_get_mac_address ();
$mac_array = @explode (',', $raw_array[6]);
if (!in_array (@md5 ('f707118e3a066ae2b7966afcf9f66a14' . $server[0]), $mac_array))
{
return '<verify status='invalid_key' message='Please contact support for a new license key.' ' . $raw_array[9] . ' />';
}

$host_array = @explode (',', $raw_array[4]);
if (!in_array (md5 ('f707118e3a066ae2b7966afcf9f66a14' . gethostbyaddr (@gethostbyname ($server[1]))), $host_array))
{
return '<verify status='invalid_key' message='Please contact support for a new license key.' ' . $raw_array[9] . ' />';
}
}
else
{
if (($array['per_install'] OR $array['per_site']))
{
if ($array['per_install'])
{
$directory_array = @explode (',', $raw_array[3]);
$valid_dir = path_translated ();
$valid_dir = @md5 ('f707118e3a066ae2b7966afcf9f66a14' . $valid_dir);
if (!@in_array ($valid_dir, $directory_array))
{
return '<verify status='invalid_key' message='Please contact support for a new license key.' ' . $raw_array[9] . ' />';
}
}

$host_array = @explode (',', $raw_array[4]);
if (!in_array (@md5 ('f707118e3a066ae2b7966afcf9f66a14' . $_SERVER['HTTP_HOST']), $host_array))
{
return '<verify status='invalid_key' message='Please contact support for a new license key.' ' . $raw_array[9] . ' />';
}

$ip_array = @explode (',', $raw_array[5]);
if (!in_array (@md5 ('f707118e3a066ae2b7966afcf9f66a14' . @server_addr ()), $ip_array))
{
return '<verify status='invalid_key' message='Please contact support for a new license key.' ' . $raw_array[9] . ' />';
}
}
}

return '<verify status='active' message='The license key is valid.' ' . $raw_array[9] . ' />';
}

function phpaudit_get_mac_address ()
{
$fp = @popen ('/sbin/ifconfig', 'r');
if (!$fp)
{
return 0 - 1;
}

$res = @fread ($fp, 4096);
@pclose ($fp);
$array = @explode ('HWaddr', $res);
if (@count ($array) < 2)
{
$array = @explode ('ether', $res);
}

$array = @explode ('', $array[1]);
$buffer[] = @trim ($array[0]);
$array = @explode ('inet addr:', $res);
if (@count ($array) < 2)
{
$array = @explode ('inet ', $res);
}

$array = @explode (' ', $array[1]);
$buffer[] = @trim ($array[0]);
return $buffer;
}

function path_translated ()
{
if (((isset ($_SERVER['PATH_TRANSLATED']) AND 0 < strlen ($_SERVER['PATH_TRANSLATED'])) AND @realpath ($_SERVER['PATH_TRANSLATED'])))
{
$path = (substr (php_uname (), 0, 7) == 'Windows' ? str_replace ('\\', '/', $_SERVER['PATH_TRANSLATED']) : $_SERVER['PATH_TRANSLATED']);
$path = substr ($path, 0, @strrpos ($path, '/'));
}

if ($_SERVER['SCRIPT_FILENAME'])
{
return substr ($_SERVER['SCRIPT_FILENAME'], 0, @strrpos ($_SERVER['SCRIPT_FILENAME'], '/'));
}

return substr ($_SERVER['ORIG_PATH_TRANSLATED'], 0, @strrpos ($_SERVER['ORIG_PATH_TRANSLATED'], '\'));
}

function server_addr ()
{
return ($_SERVER['SERVER_ADDR'] ? $_SERVER['SERVER_ADDR'] : $_SERVER['LOCAL_ADDR']);
}

global $root_dir;
global $license_set;
global $keyfile;
global $returned;
include $root_dir . 'includes/db.inc.php';
$license_set = 1;
$installed_host = 'http://www.fsrevolution.com/order';
$query_string .= 'product_id=1';
$per_server = false;
$per_install = false;
$per_site = true;
$keyfile = $root_dir . 'includes/key.php';
$array['per_server'] = $per_server;
$array['per_install'] = $per_install;
$array['per_site'] = $per_site;
$data = validate_local_key ($array);
$parser = @xml_parser_create ('');
@xml_parser_set_option ($parser, XML_OPTION_CASE_FOLDING, 0);
@xml_parser_set_option ($parser, XML_OPTION_SKIP_WHITE, 1);
@xml_parse_into_struct ($parser, $data, $values, $tags);
@xml_parser_free ($parser);
$returned = $values[0]['attributes'];
if (empty ($returned))
{
$returned['status'] = 'invalid_key';
}

if ($returned['status'] == 'invalid_key')
{
if ((0 - 1 < strpos ($returned['message'], 'expired') OR 0 - 1 < strpos ($returned['message'], 'file')))
{
$api = new IXR_Client ('http://www.fsrevolution.com/phpaudit/rpc.php');
$data = array ();
$data['api_key'] = '77104ff3cc296847ec3099e6a25e1a4c';
$data['license'] = $license;
$api->query ('license.get_status', $data);
$response = $api->getResponse ();
if ($response['status'] == 'active')
{
$data = array ();
$data['api_key'] = '77104ff3cc296847ec3099e6a25e1a4c';
$data['license_key'] = $license;
$api->query ('license.get_local_key', $data);
$local_key = $api->getResponse ();
$fp = fopen ($keyfile, 'w');
@fwrite ($fp, $local_key);
}
}
else
{
$access_details = '';
if ($per_server)
{
$server = phpaudit_get_mac_address ();
$access_details .= 'access_host=' . gethostbyaddr (@gethostbyname ($server[1]));
$access_details .= '&access_mac=' . $server[0];
}
else
{
if ($per_install)
{
$access_details .= '&access_directory=' . path_translated ();
$access_details .= '&access_ip=' . server_addr ();
$access_details .= '&access_host=' . $_SERVER['HTTP_HOST'];
}
else
{
if ($per_site)
{
$access_details .= '&access_ip=' . server_addr ();
$access_details .= '&access_host=' . $_SERVER['HTTP_HOST'];
}
}
}

header ('Location: ' . $installed_host . '/license_key_invalid.php?access=' . urlencode (@base64_encode ($access_details)));
exit ();
}
}

unset ($query_string);
unset ($per_server);
unset ($per_install);
unset ($per_site);
unset ($server);
unset ($data);
unset ($parser);
unset ($values);
unset ($tags);
?>