Get Computer Unique ID from PHP

Question

I've created an application using PHP and I'm going to sell it to my local market. I will personally be going to their locations to install/configure Apache & MySQL as well as installing my own code.

I would like a security system so that if anyone attempts to copy my code to an unauthorized machine, it won't run.

I know no one can prevent reverse engineering an application. even .exe (binary) files are cracked and with PHP (source code) anyone can do.

In my country those reverse engineers are really hard to find, so I would like to propose minimal security options like:

1) Create class (say, Navigation) which identifies system information like CPU ID, Computer name or any combination of hardware ID to make a UNIQUE_ID and matches with my given UNIQUE_ID (to the individual to whom I sold the application). If it's valid, it returns the navigation menu. Otherwise it will simply destroy the database and halt the execution by throwing an exception, maybe like:

class Navigation {

    public function d() {
        return current system UNIQUE_ID;
    }

    public function get() {
        $a = file_get_contents('hash');
        $c = $this->d();
        if (crypt($c) != $a) {
            //destory database
            throw new Exception('');
        } else {
            return "<ul><li><a>home</a></li></ul>"; //navigation menu
        }
    }

}

2) Then during the installation process I'll change system UNIQUE_ID in "hash" file, create an object, and save it into a file (nav.obj):

(install.php)

<?php
      $a=new Navigation;
      $out=serialize($a);
      file_put_contents('nav.obj', $out);

3) in header.php (which gets included in every file):

<?php
     $menu=file_get_contents('nav.obj');
     $menu=unserialize($a);
     echo $menu->get();
 ?>

I know this method isn't full proof, but I'm pretty sure that around 60% of PHP developers won't be able to crack it!

Now I only need to get current system UNIQUE_ID.

Answer 1

I have created this function to get an unique ID based on hardware (Hard disk UUID). It is possible to use different resources like machine names, domains or even hard disk size to get a better approach depending on your needs.

 function UniqueMachineID($salt = "") {
    if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
        $temp = sys_get_temp_dir().DIRECTORY_SEPARATOR."diskpartscript.txt";
        if(!file_exists($temp) && !is_file($temp)) file_put_contents($temp, "select disk 0\ndetail disk");
        $output = shell_exec("diskpart /s ".$temp);
        $lines = explode("\n",$output);
        $result = array_filter($lines,function($line) {
            return stripos($line,"ID:")!==false;
        });
        if(count($result)>0) {
            $result = array_shift(array_values($result));
            $result = explode(":",$result);
            $result = trim(end($result));       
        } else $result = $output;       
    } else {
        $result = shell_exec("blkid -o value -s UUID");  
        if(stripos($result,"blkid")!==false) {
            $result = $_SERVER['HTTP_HOST'];
        }
    }   
    return md5($salt.md5($result));
}


echo UniqueMachineID();