CRsaBcmathProvider::int2raw

static function int2raw($in)
{
	$out = '';

	if($in=='0') 
		return chr(0);

	while(bccomp($in, '0'))
	{
		$out .= chr(bcmod($in, '256'));
		$in = bcdiv($in, '256');
	}
	return $out;
}