Add missing file

BTCPayServer/Hosting/HeadersOverrideMiddleware.cs

@@ -0,0 +1,31 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Http;
+using Microsoft.Extensions.Configuration;
+using BTCPayServer.Configuration;
+
+namespace BTCPayServer.Hosting
+{
+    public class HeadersOverrideMiddleware
+    {
+        RequestDelegate _Next;
+        string overrideXForwardedProto;
+        public HeadersOverrideMiddleware(RequestDelegate next,
+            IConfiguration options)
+        {
+            _Next = next ?? throw new ArgumentNullException(nameof(next));
+            overrideXForwardedProto = options.GetOrDefault<string>("xforwardedproto", null);
+        }
+
+        public async Task Invoke(HttpContext httpContext)
+        {
+            if (!string.IsNullOrEmpty(overrideXForwardedProto))
+            {
+                httpContext.Request.Headers["X-Forwarded-Proto"] = overrideXForwardedProto;
+            }
+            await _Next(httpContext);
+        }
+    }
+}