title: php check license id with postback url
body: <p>I'm working on a php installer for a web application / software.</p>
  
  <p>The installer need a valid license ID to finish the installation (for example: "aDs34Nsi9sa").</p>
  
  <p>To check if the license ID is valid i have a php script on my main domain that check my db and return 1 if the licenseID exist and is active or 0 otherwise. This file should be called like this:</p>
  
  <pre><code>https://www.domain.com/check.php?id=aDs34Nsi9sa
  </code></pre>
  
  <p>So i'm wondering if is correct to use file_get_contents() to check the license ID via PHP..</p>
  
  <pre><code>$check = file_get_contents("https://www.domain.com/check.php?id=$license_field");
  if( $check == 1 ) {} // finish installation
  else {} // print error msg 
  </code></pre>
  
  <p>Is this way correct and secure?</p>