php+ajax实现多域名跨域登录例子(基于P3P)

#############a域名ApiController.php #################
 /*
  * 根据当前域（a域名）的cookie信息设置bstv域下的cookie及session
  * 如果为空，则清空处理
  * */
 function setckAction() {
  $clr = $this->_request->getParam("clr");
  $bts_user = ($clr) ? '' : urlencode($_COOKIE['bts_LOGGED_USER']);
  $this->view->assign("bts_user",$bts_user);
 }
 
 /*
  * 提供给bstv域下，获取当前域（a域名）的cookie及session
  * 以脚本变量返回给bstv浏览器端
  * */
 function getckAction() {
  header('P3P: CP="CURa ADMa DEVa PSAo PSDo OUR BUS UNI PUR INT DEM STA PRE COM NAV OTC NOI DSP COR"');
  echo 'var ck="'.$_COOKIE['bts_LOGGED_USER'].'";';
  echo 'var sess="'.$_SESSION['user']['uid'].'";';
  exit();
 }
#############a域名index.php #################
##### 默认指定index.php为登录返回的页面

############# B域名 api.php #################
 
 /*
  * 显示a域名域下的cookie及SESSION
  * 赋值到js变量
  * js 通过ajax写入cookie和session：如果a域名已退出，则bstv做退出处理
  * */
 function getbtsck() {
  include $this->template->getfile('api/getbtsck');
 }
 
 /*
  * a域名域下设置bstv域下的cookie及session
  * 如果为空，则清空处理
  * */
 function setck() {
  header('P3P: CP="CURa ADMa DEVa PSAo PSDo OUR BUS UNI PUR INT DEM STA PRE COM NAV OTC NOI DSP COR"');
 
  $bts_user = trim($_GET['bts_user']);
  if(!empty($bts_user)) {
   setcookie("bts_LOGGED_USER", urldecode($bts_user), time()+3600*24*365, "/", ".B域名");
   $this->cookieLoginLocal(urldecode($bts_user));
  } else {
   setcookie("bts_LOGGED_USER", $bts_user, '-1', "/", ".B域名");
   unset($_SESSION['uid']);
  }
 }
 
 function setsession() {
  $bts_user = trim($_POST['bts_user']);
  if(!empty($bts_user) && empty($_SESSION['uid'])) {
   setcookie("bts_LOGGED_USER", urldecode($bts_user), time()+3600*24*365, "/", ".B域名");
   $this->cookieLoginLocal(urldecode($bts_user));
  } else {
   echo 'uuunset';
   setcookie("bts_LOGGED_USER", $bts_user, '-1', "/", ".B域名");
   //unset($_SESSION['uid']);
  }
 }
 
 function cookieLoginLocal($cookieId){
  $cookieId = explode( '.', base64_decode($cookieId) );
  if ($cookieId[0] !== 'baitianshi' || empty($cookieId[1])) {
   return false;
  } else {
   return $this->loginLocal($cookieId[1],false,1);
  }
 }
 
 function loginLocal($uid,$password=false,$isuid=0) {
  $_SESSION['uid'] = $uid;
  return 1;
 }

############# B域名 getbtsck.html #################