How to setup ForwardedHeadersMiddleware for .NET Core 3.1 and above

README.md

Ref

• Frondoor Forward Header: https://learn.microsoft.com/en-us/azure/frontdoor/front-door-http-headers-protocol
• Official Doc: https://learn.microsoft.com/en-us/aspnet/core/host-and-deploy/proxy-load-balancer?view=aspnetcore-3.1
• https://endjin.com/blog/2023/01/correctly-configuring-asp-net-core-mvc-authentication-when-hosting-in-azure-container-apps
• https://anthonysimmon.com/securely-reverse-proxy-aspnet-core-web-apps/
• https://github.com/dotnet/aspnetcore/blob/v3.1.32/src/Middleware/HttpOverrides/test/ForwardedHeadersMiddlewareTest.cs#L238-L255
• https://github.com/dotnet/aspnetcore/blob/v3.1.32/src/Middleware/HttpOverrides/test/ForwardedHeadersMiddlewareTest.cs#L754-L775

Startup.cs

namespace IdentityServer
{
	public class Startup
	{
		public void ConfigureServices(IServiceCollection services)
		{
			services.Configure<ForwardedHeadersOptions>(options =>
			{
				options.ForwardedHeaders = ForwardedHeaders.XForwardedHost | ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto;
				options.KnownNetworks.Clear(); 
				options.KnownProxies.Clear();
			});
			
			// other middleware configuration...
		}
		
		 public void Configure(IApplicationBuilder app)
		 {
			 app.UseForwardedHeaders();
			 
			 // other middleware registrations...
		 }
	}
}