Implement Windows Authentication for .NET Core 3.1 Web App

Question

I have created an internal Razor Pages Web App using .NET Core 3.1. I want to only give access to users who are part of an Active Directory group. I don't want them to have to go through the hassle of creating yet more username/passwords. But I haven't been able to get it working.

I followed the Microsoft Documentation and created a starter app and added a web.config file as described in the docs. When I launch from Visual Studio 2019, the browser displays

1. How can I get this working?
2. How do I set it up to allow only users in a certain group to have access? I'm not concerned with roles at the moment. I want to allow full access, but lock out anyone not in the group. Thanks.

Answer 1

I was able to figure this out. I had my IT department add a special group for the users of the application and search for that group.

    public bool IsInGroup(string groupName)
    {
        var groups = new List<string>();
        
        var wi = (WindowsIdentity)User.Identity;
        if (wi.Groups != null)
            foreach (var group in wi.Groups)
            {
                try
                {
                    groups.Add(group.Translate(typeof(NTAccount)).ToString());
                }
                catch (Exception ex)
                {
                    logger.LogInformation($"User = {User.Identity.Name}; Error = {ex.Message}");
                    throw;
                }
            }
        return groups.Contains(groupName);
    }