Best and Latest approach to manage Roles and permission for user in

I am going to make an application in which I want to implement role based authentication , I also wanted to populate dynamic menu based on user Role to show him, I also want to implement Role based rights Like Edit Delete Create , is there any off the shelf Library for .NET MVC to do it .

Secondly I already have users Tables in which i have 20 columns , Now If I use identity It will create its separate aspnetuser table so how do I map my User Table to this ASPnetUSer table If I use identity.