adjust fido content type with middleware

src/Api/Controllers/TwoFactorController.cs

@@ -136,7 +136,7 @@ namespace Bit.Api.Controllers
         }
 
         [HttpGet("~/app-id.json")]
-        //[Produces("application/fido.trusted-apps+json")]
+        [Produces("application/fido.trusted-apps+json")]
         [AllowAnonymous]
         public string GetU2fAppId()
         {
@@ -149,7 +149,7 @@ namespace Bit.Api.Controllers
                         version = new
                         {
                             major = 1,
-                            minor = 1
+                            minor = 0
                         },
                         ids = new string[]
                         {

src/Api/Middleware/AdjustHeadersMiddleware.cs

@@ -0,0 +1,38 @@
+using Bit.Core;
+using Microsoft.AspNetCore.Http;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace Bit.Api.Middleware
+{
+    public class AdjustHeadersMiddleware
+    {
+        private readonly RequestDelegate _next;
+
+        public AdjustHeadersMiddleware(RequestDelegate next)
+        {
+            _next = next;
+        }
+
+        public async Task Invoke(HttpContext httpContext, CurrentContext currentContext)
+        {
+            httpContext.Response.OnStarting((state) =>
+            {
+                if(httpContext.Response.Headers.Count > 0 && httpContext.Response.Headers.ContainsKey("Content-Type"))
+                {
+                    var contentType = httpContext.Response.Headers["Content-Type"].ToString();
+                    if(contentType.StartsWith("application/fido.trusted-apps+json"))
+                    {
+                        httpContext.Response.Headers.Remove("Content-Type");
+                        httpContext.Response.Headers.Append("Content-Type", "application/fido.trusted-apps+json");
+                    }
+                }
+
+                return Task.FromResult(0);
+            }, null);
+
+
+            await _next.Invoke(httpContext);
+        }
+    }
+}

src/Api/Startup.cs

@@ -141,6 +141,8 @@ namespace Bit.Api
                 })
                 .AddDebug();
 
+            app.UseMiddleware<AdjustHeadersMiddleware>();
+
             // Rate limiting
             app.UseMiddleware<CustomIpRateLimitMiddleware>();