Adding the JwtBearer middleware diagnostics (in addition to the OpenId Connect middleware)

Author: jmprieur

Microsoft.Identity.Web/Resource/JwtBearerMiddlewareDiagnostics.cs

@@ -0,0 +1,91 @@
+using Microsoft.AspNetCore.Authentication.JwtBearer;
+using System;
+using System.Diagnostics;
+using System.Threading.Tasks;
+
+namespace Microsoft.Identity.Web.Resource
+{
+    /// <summary>
+    /// Diagnostics for the JwtBearer middleware (used in Web APIs)
+    /// </summary>
+    public class JwtBearerMiddlewareDiagnostics
+    {
+        /// <summary>
+        /// Invoked if exceptions are thrown during request processing. The exceptions will be re-thrown after this event unless suppressed.
+        /// </summary>
+        static Func<AuthenticationFailedContext, Task> onAuthenticationFailed;
+
+        /// <summary>
+        /// Invoked when a protocol message is first received.
+        /// </summary>
+        static Func<MessageReceivedContext, Task> onMessageReceived;
+
+        /// <summary>
+        /// Invoked after the security token has passed validation and a ClaimsIdentity has been generated.
+        /// </summary>
+        static Func<TokenValidatedContext, Task> onTokenValidated;
+
+        /// <summary>
+        /// Invoked before a challenge is sent back to the caller.
+        /// </summary>
+        static Func<JwtBearerChallengeContext, Task> onChallenge;
+
+        /// <summary>
+        /// Subscribes to all the JwtBearer events, to help debugging, while
+        /// preserving the previous handlers (which are called)
+        /// </summary>
+        /// <param name="events">Events to subscribe to</param>
+        public static JwtBearerEvents Subscribe(JwtBearerEvents events)
+        {
+            if (events == null)
+            {
+                events = new JwtBearerEvents();
+            }
+
+            onAuthenticationFailed = events.OnAuthenticationFailed;
+            events.OnAuthenticationFailed = OnAuthenticationFailed;
+
+            onMessageReceived = events.OnMessageReceived;
+            events.OnMessageReceived = OnMessageReceived;
+
+            onTokenValidated = events.OnTokenValidated;
+            events.OnTokenValidated = OnTokenValidated;
+
+            onChallenge = events.OnChallenge;
+            events.OnChallenge = OnChallenge;
+
+            return events;
+        }
+
+        static async Task OnMessageReceived(MessageReceivedContext context)
+        {
+            Debug.WriteLine($"1. Begin {nameof(OnMessageReceived)}");
+            // Place a breakpoint here and examine the bearer token (context.Request.Headers.HeaderAuthorization / context.Request.Headers["Authorization"])
+            // Use https://jwt.ms to decode the token and observe claims
+            await onMessageReceived(context);
+            Debug.WriteLine($"1. End - {nameof(OnMessageReceived)}");
+        }
+
+        static async Task OnAuthenticationFailed(AuthenticationFailedContext context)
+        {
+            Debug.WriteLine($"99. Begin {nameof(OnAuthenticationFailed)}");
+            // Place a breakpoint here and examine context.Exception
+            await onAuthenticationFailed(context);
+            Debug.WriteLine($"99. End - {nameof(OnAuthenticationFailed)}");
+        }
+
+        static async Task OnTokenValidated(TokenValidatedContext context)
+        {
+            Debug.WriteLine($"2. Begin {nameof(OnTokenValidated)}");
+            await onTokenValidated(context);
+            Debug.WriteLine($"2. End - {nameof(OnTokenValidated)}");
+        }
+
+        static async Task OnChallenge(JwtBearerChallengeContext context)
+        {
+            Debug.WriteLine($"55. Begin {nameof(OnChallenge)}");
+            await onChallenge(context);
+            Debug.WriteLine($"55. End - {nameof(OnChallenge)}");
+        }
+    }
+}

Microsoft.Identity.Web/Resource/OpenIdConnectMiddlewareDiagnostics.cs

@@ -6,6 +6,10 @@
 
 namespace Microsoft.Identity.Web.Resource
 {
+    /// <summary>
+    /// Diagnostics used in the Open Id Connect middleware
+    /// (used in Web Apps)
+    /// </summary>
     public class OpenIdConnectMiddlewareDiagnostics
     {
         //