我有一个主要的领域：main.com，子：test1.main.com，test2.main.com和其他领域one.com，two.com。

现在完成如下操作：

ini_set("session.cookie_domain", ".main.com");

$domain = 'main.com';

login.php

$user = $db->query("SELECT id, login FROM users WHERE email=? AND password=?", 
array($email, $password), "rowassoc");

if($user)
{
  $_SESSION['user_id'] = $user['id'];
  $_SESSION['user_name'] = $user['login'];

  $time = 100000;

  setcookie('email', $email, time() + $time, "/", "." . $domain);
  setcookie('password', $password, time() + $time, "/", "." . $domain);

  header('Location: http://' . $user['login'] . "." . $domain);
  exit;
}

在每个页面上添加：

if(!isset($_SESSION['user_id']))
{
  if(isset($_COOKIE['email']) && isset($_COOKIE['password']))
  {
    $email = $_COOKIE['email'];
    $password = $_COOKIE['password'];

    $user = $db->query("SELECT id, login FROM users WHERE email=? AND password=?",
    array($email, $password), "rowassoc");

    if($user)
    {
      $_SESSION['user_id'] = $user['id'];
      $_SESSION['user_name'] = $user['login'];
    }
  }
}
else
{
  $user = $db->query("SELECT id, login FROM users WHERE id=?", 
  array($_SESSION['user_id']), "rowassoc");


  if(!$user)
  {
    setcookie('email', '', time() , "/", "." . $domain);
    setcookie('password', '', time() , "/", "." . $domain);
    unset($_SESSION['user_id']);

    session_destroy();
    setcookie("PHPSESSID","",time(), "/", "." . $domain);
  }
  else
  {
    $_SESSION['user_id'] = $user['id'];
    $_SESSION['user_name'] = $user['login'];
  }
}

logout.php

if(isset($_SESSION['user_id']))
{
  setcookie('email', '', time() , "/", "." . $domain);
  setcookie('password', '', time() , "/", "." . $domain);
  unset($_SESSION['user_id']);
  unset($_SESSION['user_name']);

  session_destroy();
  setcookie("PHPSESSID","",time(), "/", "." . $domain);

  header('Location: /main');
  exit;
}

但它仅适用于域main.com及其子域test1.main.com，test2.main.com。

我需要以某种方式保存会话和其他域one.com，two.com。

如何最好地进行安全身份验证，如果有解决方案，我真的很困惑，请举例说明。