How to determine if a user is an administrator from an unprivileged application with Win32?

To determine if a user is an administrator from an unprivileged application using Win32 APIs, you can use the CheckTokenMembership function. This function checks if a user is a member of a specified security group, such as the Administrators group.

Here's a basic example of how you can use the CheckTokenMembership function to determine if the current user is an administrator:

cCopy code
#include <Windows.h>

#include <iostream>



bool IsUserAdmin() {

    BOOL bIsAdmin = FALSE;

    SID_IDENTIFIER_AUTHORITY NtAuthority = SECURITY_NT_AUTHORITY;

    PSID AdministratorsGroup;



    if (AllocateAndInitializeSid(&NtAuthority, 2,

        SECURITY_BUILTIN_DOMAIN_RID, DOMAIN_ALIAS_RID_ADMINS,

        0, 0, 0, 0, 0, 0, &AdministratorsGroup)) {

        

        if (!CheckTokenMembership(NULL, AdministratorsGroup, &bIsAdmin)) {

            bIsAdmin = FALSE;

        }



        FreeSid(AdministratorsGroup);

    }

    return (bIsAdmin == TRUE);

}



int main() {

    if (IsUserAdmin()) {

        std::cout << "User is an administrator." << std::endl;

    } else {

        std::cout << "User is not an administrator." << std::endl;

    }



    return 0;

}

In this example, the IsUserAdmin function checks if the current user is a member of the Administrators group using the CheckTokenMembership function. The function returns true if the user is an administrator and false if not.

Please note that while this approach is useful for determining if a user is an administrator, it does not guarantee that the application will have administrative privileges. Admin rights may still be required for certain operations, and UAC (User Account Control) may affect the actual privileges granted to the application at runtime.