Service Fabric asp.net core AAD

Question

I have an asp.net core app setup using kestrel. I'm using the service fabric reverse proxy to access it. i'm trying to use azure active directory for authentication. However, whenever the app attempts to login to aad, the redirecturi is always the address of the node instance instead of the reverse proxy url. how do i get the redirecturi to be the reverse proxy url?

Answer 1

I had the same issue once, i can provide you with some code that does the trick on my asp.net core 2.2 app.

If the code does not work, the key thing to google is asp.net core authentication behind reverse proxy (ignore any service fabric stuff).

In your ConfigureServices method

services.AddAuthentication(AzureADDefaults.AuthenticationScheme)
                    .AddAzureAD(options => Configuration.Bind("AzureAd", options));

                services.Configure<OpenIdConnectOptions>(AzureADDefaults.OpenIdScheme, options =>
                {
                    options.Authority = options.Authority + "/v2.0/";
                    options.TokenValidationParameters.ValidateIssuer = true;
                });

                services.Configure<ForwardedHeadersOptions>(options =>
                {
                    options.ForwardLimit = null;
                    options.RequireHeaderSymmetry = false;
                    options.KnownNetworks.Clear(); // This is not really that smart - we should probably add a list of known proxies/networks
                    options.KnownProxies.Clear();
                    options.ForwardedHeaders = ForwardedHeaders.XForwardedHost |
                        ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto;
                });

And in your Configure method:

app.UseForwardedHeaders();
                app.Use((context, next) =>
                {
var fabricServiceNinja = Environment.GetEnvironmentVariable("SOMEENVIRONMENTVAR");
var fabricServiceUri = new Uri(fabricServiceNinja);
var servicePathBase = fabricServiceUri.AbsolutePath;
context.Request.PathBase = new PathString(servicePathBase);
return next();
                });