PHP Basic Authentication

auth.php

<?php
	/* 
	* PHP-Basic-Auth 
	* Author: Ano Tisam
	* Date: 11/10/2016
	* Description: A simple basic auth script. When user tries to access a page that requires 
	* this script it asks for a username and password. Passwords are stored in a $users array as below.
	*/
	function pc_validate($user,$pass) {
		/* replace with appropriate username and password checking,
		   such as checking a database */
		$users = array(
					   'user1'  => 'password1',
					   'user2'  => 'password2',
					   'user3' => 'password3'
					   );
		if (isset($users[$user]) && ($users[$user] == $pass)) {
			return true;
		} else {
			return false;
		}
	}
?>

index.php

<?php
  //Include the Library
  require_once("auth.php");

  // How to use BASIC AUTH
	if (!pc_validate($_SERVER['PHP_AUTH_USER'],$_SERVER['PHP_AUTH_PW'])){
		$realm = 'Licensing API '.date('Y-m-d');
		header('WWW-Authenticate: Basic realm="'.$realm.'"');
		header('HTTP/1.0 401 Unauthorized');
		echo "You need to enter a valid username and password.";
		exit;
	}

  //...Your API Code
?>