Dcrypt\Support::hex2bin PHP Метод

    protected static function hex2bin($hexstr)
    {
        if (\function_exists('hex2bin')) {
            return \hex2bin($hexstr);
        }
        $n = \strlen($hexstr);
        $sbin = '';
        $i = 0;
        while ($i < $n) {
            $a = \substr($hexstr, $i, 2);
            $c = \pack('H*', $a);
            $sbin .= $c;
            $i += 2;
        }
        return $sbin;
    }