UCenter跨域、单点登陆机制分析

$_SCONFIG["uc_status"]为 uc状态，这里已在common.php 中有定义，如果不是当前应用则为1，然后看client.php的uc_user_synlogin函数

function uc_user_synlogin($uid) {
    $uid = intval($uid);
    $return = uc_api_post("user", "synlogin", array("uid"=>$uid));
    return $return;
}
uc_api_post("user", "synlogin", array("uid"=>$uid)是打开ucenter下的指定action 这里是control/user.php的onsynlogin方法，同时传递参数uid,关于如何打开ucenter 函数在uc_api_post；
在onsynlogin方法中
function onsynlogout() {
        $this->init_input();
        if($this->app["synlogin"]) {
            $synstr = "";
            foreach($this->cache["apps"] as $appid => $app) {
                if($app["synlogin"] && $app["appid"] != $this->app["appid"]) {
                    $synstr .= "<script type="text/javascript" src="".$app["url"]."/api/".$app["apifilename"]."?time=".$this->time."&code=".urlencode($this->authcode("action=synlogout&time=".$this->time, "ENCODE", $app["authkey"]))."" reload="1"></script>";
                }
            }
            return $synstr;
        }
        return "";
    }
onsynlogin 函数通过循环，对系统下的所有应用（在data/cache/setting.php）做JS调用
在js中对每个应用下的api/uc.php 进行访问并进行cookie设置
返回到uchome.在每 个应用下的api目录有个uc.php文件查找$action == "synlogin"下面是进行cookie设置
function synlogin($get, $post) {
        global $_SGLOBAL;
       
        if(!API_SYNLOGIN) {
            return API_RETURN_FORBIDDEN;
        }
   

        obclean();
        header("P3P: CP="CURa ADMa DEVa PSAo PSDo OUR BUS UNI PUR INT DEM STA PRE COM NAV OTC NOI DSP COR"");
   
        $cookietime = 31536000;
        $uid = intval($get["uid"]);
        $query = $_SGLOBAL["db"]->query("SELECT uid, username, password FROM ".tname("member")." WHERE uid="$uid"");
        if($member = $_SGLOBAL["db"]->fetch_array($query)) {
            include_once S_ROOT."./source/function_space.php";
            $member = saddslashes($member);
            $space = insertsession($member);

            ssetcookie("auth", authcode("$member[password] $member[uid]", "ENCODE"), $cookietime);