/**
 * 用户登陆验证的类
 *
 * @param 
 * @arrange (512.笔记) jb51.cc
 **/
class Auth
{
 var $user_id;
 var $username;
 var $password;
 var $ok;
 var $salt = "34asdf34";
 var $domain = ".domain.com";
 
 function Auth()
 {
  global $db;
 
  $this->user_id = 0;
  $this->username = "Guest";
  $this->ok = false;
 
  if(!$this->check_session()) $this->check_cookie();
 
  return $this->ok;
 }
 
 function check_session()
 {
  if(!empty($_SESSION['auth_username']) && !empty($_SESSION['auth_password']))
   return $this->check($_SESSION['auth_username'],$_SESSION['auth_password']);
  else
   return false;
 }
 
 function check_cookie()
 {
  if(!empty($_COOKIE['auth_username']) && !empty($_COOKIE['auth_password']))
   return $this->check($_COOKIE['auth_username'],$_COOKIE['auth_password']);
  else
   return false;
 }
 
 function login($username,$password)
 {
  global $db;
  $db->query("SELECT user_id FROM users WHERE username = '$username' AND password = '$password'");
  if(MysqL_num_rows($db->result) == 1)
  {
   $this->user_id = MysqL_result($db->result,0);
   $this->username = $username;
   $this->ok = true;
 
   $_SESSION['auth_username'] = $username;
   $_SESSION['auth_password'] = md5($password . $this->salt);
   setcookie("auth_username",$username,time()+60*60*24*30,"/",$this->domain);
   setcookie("auth_password",md5($password . $this->salt),$this->domain);
 
   return true;
  }
  return false;
 }  
 
 function check($username,$password)
 {
  global $db;
  $db->query("SELECT user_id,password FROM users WHERE username = '$username'");
  if(MysqL_num_rows($db->result) == 1)
  {
   $db_password = MysqL_result($db->result,1);
   if(md5($db_password . $this->salt) == $password)
   {
    $this->user_id = MysqL_result($db->result,0);
    $this->username = $username;
    $this->ok = true;
    return true;
   }
  }   
  return false;
 }
 
 function logout()
 {
  $this->user_id = 0;
  $this->username = "Guest";
  $this->ok = false;
 
  $_SESSION['auth_username'] = "";
  $_SESSION['auth_password'] = "";
 
  setcookie("auth_username","",time() - 3600,$this->domain);
  setcookie("auth_password",$this->domain);
 }
 
}


/***   来自编程之家 jb51.cc（jb51.cc）   ***/