Exception triggered by AuthorizeAttribute on the first page loaded in a circuit

[Kevin Krumwiede]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

To learn how auth works in Blazor, I'm writing a minimal implementation from scratch. In the process, I've encountered a strange error.

If the first page loaded in a circuit does not have [Authorize], everything works perfectly. You can freely navigate to a page that does have [Authorize], and the page is displayed as expected. That is, you get either the page content or a "not authorized" message depending on whether the user is authenticated.

However, if the first page loaded in a circuit does have [Authorize], then the app crashes with an error about not being able to find an IAuthenticationService.

This only affects AuthorizeAttribute. There is no error if the first page loaded in the circuit contains an <AuthorizeView>.

Expected Behavior

AuthorizeAttribute should have the same effect on the first page loaded in a circuit as it does on subsequent pages.

Steps To Reproduce

This repo contains the Blazor Web App template and my changes in separate commits for easy review. The README contains instructions for an easy way to see the problem.

https://github.com/kjkrum/BlazorAuthWtf

Exceptions (if any)

System.InvalidOperationException: Unable to find the required 'IAuthenticationService' service. Please add all the required services by calling 'IServiceCollection.AddAuthentication' in the application startup code.

   at Microsoft.AspNetCore.Authentication.AuthenticationHttpContextExtensions.GetAuthenticationService(HttpContext context)

   at Microsoft.AspNetCore.Authentication.AuthenticationHttpContextExtensions.ChallengeAsync(HttpContext context)

   at Microsoft.AspNetCore.Authorization.Policy.AuthorizationMiddlewareResultHandler.<>c__DisplayClass0_0.<<HandleAsync>g__Handle|0>d.MoveNext()

--- End of stack trace from previous location ---

   at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)

   at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddlewareImpl.Invoke(HttpContext context)

.NET Version

8.0

Anything else?

No response