ServerSide Blazor: Windows authentication not working when enabling windows AND anonymous authentication

[audacity76]

Describe the bug

For an internal ServerSide Blazor website I need windows authentication and anonymous access. I enabled both authentication methods in the project properties but the windows authentication does not happen.

To Reproduce

Configure following component page

@page "/authorized"

@attribute [Authorize]

@inject AuthenticationStateProvider AuthenticationStateProvider

<p>User: @User</p>

@code{
    public string User { get; set; }
    
    protected override async Task OnInitializedAsync()
    {
        var auth = await AuthenticationStateProvider.GetAuthenticationStateAsync();
        User = auth.User.Identity.Name; // null!
    }
}

Further technical details

• ASP.NET Core version 3.0.0
• VS 16.3.8

[javiercn]

@audacity76 thanks for contacting us.

@SteveSandersonMS Do you have any thoughts here?

[mkArtakMSFT]

Thanks for contacting us. The auth in Blazor server should work very similar with non-Blazor situations. Do you observe similar issue in an MVC app for example?

[audacity76]

Just tried it with the latest version 3.1.1 but still the Blazor Server app ignores the [Authorized] attribute. I created a repo so you can compare the behaviors: https://github.com/audacity76/WindowsAuthAspNetCore

[kempcalalo]

Experiencing the exact same issue if both windows and anonymous authentication are enabled in a Blazor App.

[mkArtakMSFT]

Thanks for sharing a repro, @audacity76. Bringing this up for triage tomorrow.