MSISDN Authentication sample

auth.php

<?php

/*
**  VALIDATE SUBSCRIPTION
**  @desc Redirect to Subscription Page if Number not detected or Subscription has expired
** Ref: include/auth.php
*/

function validate_subscription(){

  $expiry_date = isset($_SESSION['expiryDate']) ? $_SESSION['expiryDate'] : null;

  // Logout
  if (isset($_GET['do']) && $_GET['do'] == 'logout') {
    # Set Expiry date to old
    $expiry_date = date('2016-01-01');
  }

  if ( isset($_GET['m']) && isset($_GET['d']) ) {
    $_SESSION['user_data'] = null;

      // Decode MSISDN and accompanying data
    foreach($_GET as $loc => $item) $_GET[$loc] = str_rot13($item);
    
    $_SESSION['_msisdn'] = $_GET['m'];
    $_SESSION['expiryDate'] = $_GET['d'];
    $expiry_date = $_GET['d'];

    // Empty GET array
    $_GET = array();

  }

  if ( !isset($_SESSION['_msisdn']) || ( isset($_SESSION['_msisdn']) && isExpired($expiry_date) ) )
    header('Location: http://5.101.138.139/subscription/s/[SERVICE_ID]');
  // Go to Site
}


/*
* Check if subscription is expired for user or user is new
* @return BOOL
*/
function isExpired($expiry_date){

  $cur_date = date('Y-m-d', $_SERVER['REQUEST_TIME']);

  if ( $expiry_date < $cur_date || is_null($expiry_date) ) {
    session_destroy();
    return true;
  }

  return false;
}