CORB OpenID Connect /连接/授权端点（Identity Server 4）

Question

I'm currently running into a strange issue. We're hosting an ASP.CORE 2.1 application that uses an Identity Server 4 as it's federated gateway.

At first navigation to the site using Chrome it's empty - leaving only a small hint in the console that CORB has blocked something.

Looking into fiddler it seems that it's blocking the "hidden" form that posts back to the applications /signin-oidc middleware.

But the strange thing is upon a refresh it all works and CORB is no longer an issue. Looking at the corresponding "good" response in fiddler the same headers are identical.

I can verify that the form_post from Identity Server isn't reaching the application in fiddler, debugging the OpenID events and each request and I get nada.

app.Use(async (context, next) =>
        {
            if (!context.User.Identity.IsAuthenticated)
            {
                   // look to see if bearer is present instead of cookies
                    string auth = context.Request.Headers["Authorization"];
                    if (string.IsNullOrEmpty(auth) || !auth.StartsWith("Bearer ", StringComparison.OrdinalIgnoreCase))
                    {
                       // request needs to be authenticated
                        await context.ChallengeAsync();
                    }
                    else
                    {
                        await next();
                    }
            }
            else
            {
                // all is good, continue
                await next();
            }
        });

Why is CORB blocking the initial request? Can it be a behavior in browser navigation versus refresh?

Here's the client configuration with the events I'm debugging:

services.AddAuthentication(opts =>
            {
                opts.DefaultChallengeScheme = "oidce";
                opts.DefaultAuthenticateScheme = CookieAuthenticationDefaults.AuthenticationScheme;
            })
                .AddCookie(opts =>
                {
                    opts.SessionStore = new MemoryCacheTicketRepository();
                    opts.ExpireTimeSpan = TimeSpan.FromHours(2);
                })
                .AddIdentityServerAuthentication("Bearer", opts =>
                {
                    ...
                })
                .AddOpenIdConnect("oidce", opts =>
                {
                    ...
                    opts.Events = new Microsoft.AspNetCore.Authentication.OpenIdConnect.OpenIdConnectEvents()
                    {
                        OnAuthenticationFailed = async p =>
                        {
                            var test = p;
                        },
                        OnAuthorizationCodeReceived = async p =>
                        {
                            var test = p;
                        },
                        OnMessageReceived = async p =>
                        {
                            var test = p;
                        },
                        OnRemoteFailure = async p =>
                        {
                            var test = p;
                        },
                        OnTicketReceived = async p =>
                        {
                            var test = p;
                        },
                        OnTokenResponseReceived = async p =>
                        {
                            var test = p;
                        },
                        OnTokenValidated = async p =>
                        {
                            var test = p;
                        }

                    };
                });

Since there's no difference in the headers present on a good or a bad response I'm guessing 'Access-Control-Allow-Headers' with 'Content-Type' isn't the issue. What could it be?

Answer 1

Following Vidmantas Blazevicius comments I tried adding CSPS headers and it actually worked.

Small gotcha, at first I applied the headers in the ASP CORE application which serves the SPA.

app.Use(async (context, next) =>
{
    context.Response.Headers.Add("Content-Security-Policy",
                                "default-src 'self' https://localhost:5000; script-src 'unsafe-eval'; script-src-elem 'unsafe-inline';");
        if (!context.User.Identity.IsAuthenticated)
        {
                // look to see if bearer is present instead of cookies
            string auth = context.Request.Headers["Authorization"];
            if (string.IsNullOrEmpty(auth) || !auth.StartsWith("Bearer ", StringComparison.OrdinalIgnoreCase))
                {
                   // request needs to be authenticated
                    await context.ChallengeAsync();
                }
                else
                {
                    await next();
                }
        }
        else
        {
            // all is good, continue
            await next();
        }
    });

That didn't really seem to do the trick so I tried adding it to index.html that the app was serving.

<meta http-equiv="Content-Security-Policy" content="default-src 'self' https://localhost:5000; script-src 'unsafe-inline' 'unsafe-eval' 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data:;">

And so far it seems like it actually works.