[SharePoint Apps] Show current user permissions on SharePoint hosted Apps

Hello

I created a SharePoint App that shows the user permissions of the list. It is SharePoint Hosted app.

I have a problem with authorization.

As I read, it is impossible to use the app policy on SharePoint Hosted app. It is limited to the current user rights.

So I cannot get the user rights in an hosted SharePoint app for this user that does have enough rights attributed ?

thanks