Logout Shredder

<?
// Logout shredder. If any sort of sensitive information is stored in session variables, use this to shred them upon logout.
session_start();
foreach($_SESSION as $i => $v) {
  // Shred everything. Leave absolutely no trace
  if(!is_array($v)) {
    $l = strlen($v);
    unset($v);
    $_SESSION[$i] = str_repeat(chr(246), $l);
    $_SESSION[$i] = str_repeat(chr(0), $l);
    $_SESSION[$i] = str_repeat(chr(255), $l);
    $_SESSION[$i] = openssl_random_pseudo_bytes($l);
    $_SESSION[$i] = str_repeat(chr(0), $l);
    $_SESSION[$i] = str_repeat(chr(255), $l);
    $_SESSION[$i] = openssl_random_pseudo_bytes($l);
    $_SESSION[$i] = str_repeat(chr(0), $l);
  }
  unset($_SESSION[$i]);
}
session_regenerate_id(true);
header("Location: /");
exit;
?>