How to dynamically authorize users in MVC inside Application_Start - asp.net-mvc-5

Question

I am using MVC 5 to build an application. In my web.config I have defined a custom section which I will use to display menu to user. It is something like:
<Menus>
<Menu>
<MainMenu Title="Home"></MainMenu>
<SubMenus>
<SubMenu Title="Page1" PageName="home/index" ADGroup="BusinessUsers">
<SubMenu Title="Page2" PageName="home/index2" ADGroup="ITUsers">
</SubMenus>
</Menu>
<Menu>
<MainMenu Title="About Us"></MainMenu>
<SubMenus>
<SubMenu Title="Another Page1" PageName="about/mypage1" ADGroup="BusinessUsers">
<SubMenu Title="Some Other Page" PageName="about/mypage2" ADGroup="OtherUsers">
</SubMenus>
</Menu>
</Menus>
I am using Windows authentication and everyone will have access via AD groups. By default I have denied access to all users using authorization rule in web.config like below:
<authorization><deny users="*"/></authorization>
Is it possible to define authorization rules based on MENU above in Application_Start at runtime? Something like:
Global.Filters.AuthorizeUser("BusinessUsers", "home/index, about/mypage1");
Global.Filters.AuthorizeUser("ITUsers", "home/index2");

Answer 1

What you're doing here isn't a standard way of defining a menu, so there is no standard way of enforcing authorization on it. You will need to implement it yourself.
Somewhere in your code during a request, you will have to loop through each SubMenu and use HttpContext.Current.User.IsInRole("DOMAIN\\GroupName") to test whether the user is in the appropriate group. I can't give you any further direction than that without seeing more of your code.
I'm sure you have your reasons for putting this in web.config, but what I have done in my own projects is define the menu in a partial view and check the roles right in the view:
#if (HttpContext.Current.User.IsInRole("DOMAIN\\GroupName") {
Some menu item
}
If you're worried about being able to update the menu items without recompiling the whole project, then that's still fine since the cshtml files aren't compiled anyway - you can update it on the fly.