What is the best way to get the value of what user is logged in?

Question

I have a Windows form application that users can log into. The application is alone and doesn't connect with anything or anyone.

Besides creating a global variable, how could I have an easily accesible variable to check the current users permissions?

A not so kosher way of doing things is just pass the ID of the userType in the Form constructor and according to that, .Enable = false; buttons they don't have permissions to use.

Thanks!

Answer 1

If you want the id of the currently logged on Windows user (ie. the user that the application is running as), there are two ways of getting it:

1. By putting AppDomain.CurrentDomain.SetPrincipalPolicy(PrincipalPolicy.WindowsPrincipal); in your startup, you can use Thread.CurrentPrincipal to get the user's security principal.
2. You can use WindowsIdentity.GetCurrent() to get the current user's identity. You can then create a security principal using new WindowsPrincipal(identity).

Both of these are equivalent, and will get you a security principal that has an IsInRole method that can be used to check permissions.

Answer 2

Use the WindowsIdentity class for getting the users Identity, found under System.Security.Principal.WindowsIdentity.

WindowsIdentity current = WindowsIdentity.GetCurrent();
Console.WriteLine("Name:" + current.Name);

Use the WindowsPrincipal class for getting the users Roles, found under System.Security.Principal.WindowsPrincipal.

WindowsIdentity current = WindowsIdentity.GetCurrent();
WindowsPrincipal principal = new WindowsPrincipal(current);

if (principal.IsInRole("your_role_here")
{
Console.WriteLine("Is a member of your role");
}