Capturing traffic from .Net app to https://localhost using Fiddler

Recently I was trying to capture traffic from my .Net help to a site hosted in IIS Express at  https://localhost:port
The issue was that fiddler wasn't capturing these requests. I found various alternatives like using IP address or machine name but that would results in certificate errors due to host name mismatch.

Finally found the option of using https://localhost.fiddler:port instead of https://localhost:port which would then capture the traffic in Fiddler.

Configuring timeout on an existing Task using Extension method

I was using SignalR IHubProxy and wanted to configure timeout on the task returned.
The problem is that I didn't create this task and hence couldn't set a timeout using cancellation token, etc
Thanks to the support from SignalR team, I was able to set Timeout using Extension method
Below is the sample code

public static class TaskExtensions

{

    public static async Task<T> TimeoutAfter<T>(this Task<T> task, TimeSpan timeout)

    {

        var delayTask = Task.Delay(timeout);

        var finishedFirst = await Task.WhenAny(task, delayTask);

        if (finishedFirst != delayTask)

        {

            // Task finished before the timeout

            return ((Task<T>)finishedFirst).Result;

        } 

        // Task didn't finish before the timeout

        // Note: Technically the task wasn't canceled at all, it's still running but there's no

        //       way to stop it from here but the caller can handle this exception and retrieve

        //       the task from the InnerException.Task property if further action is desired.

        throw new TaskCanceledException(

            "The task didn't complete within the specified time.",

            new TaskCanceledException(task));

    } 

    private static async void ExampleUsage()

    {

        var exampleAsync = new Func<Task<int>>(() => Task.FromResult(1)); 

        try

        {

            var result = await exampleAsync().TimeoutAfter(TimeSpan.FromSeconds(10));

        }

        catch (TaskCanceledException)

        {

            // The task timed out

        }

    }

}

Using FiddlerCore on Remote devices

Some time back, I wrote a blog on FiddlerCore http://www.anujchaudhary.com/2013/05/automated-website-testing-with.html

I had created a windows application using FiddlerCore and was interested in using it on remote devices like WindowsPhone/iOS/Android/etc

After some investigations, I was able to achieve this goal by doing the following:

Create Fiddler Root certificate using CertMaker.dll and BCMakeCert.dll

CertMaker.dll uses the BouncyCastle C# library (BCMakeCert.dll) to generate new certificates which are compatible with iOS devices.

Make sure these dlls are in the folder where your executable and FiddlerCore.dll live.

The root certificate is created in the below method

public void MakeCert()

        {

            if (!CertMaker.rootCertExists())

            {

                if (!CertMaker.createRootCert())

                {

                    throw new Exception("Unable to create cert for FiddlerCore.");

                }

                else

                {

                    Logger.Log("Created Fiddler Root Cert for Https Inspection");

                }

            }

            X509Store certStore = new X509Store(StoreName.Root,StoreLocation.LocalMachine);

            certStore.Open(OpenFlags.ReadWrite);

            try

            {

                certStore.Add(CertMaker.GetRootCertificate());

            }

            finally

            {

                certStore.Close();

            }

        }

Start Fiddler Application on a well-known port

Start Fiddler Application on a well-known port which will allow inbound connections e.g. 9999

FiddlerApplication.Startup(9999, FiddlerCoreStartupFlags.Default);

Use FiddlerCoreStartupFlags.Default

Start FiddlerApplication with FiddlerCoreStartupFlags.Default. This will ensure that remote connections are allowed and https decryption is enabled
FiddlerApplication.Startup(9999, FiddlerCoreStartupFlags.Default);

Enable Echo Service

Echo service needs to be enabled so that the root certificate can be downloaded and installed on the remote devices for https inspection. This is done by setting the below preference

FiddlerApplication.Prefs.SetBoolPref("fiddler.echoservice.enabled", true); 

Configure proxy on Remote devices

1.       On the remote device, go to http://<local machine IP>:9999 and download and install the Fiddler Root certificate

2.       On the remote device, go to network settings and add/change the proxy to local machine IP and port 9999

3.       Now you will be able to dogfood new stuff on the remote device and view metrics/logs on the local windows machine.

 Once the above steps are done, everything else is similar to what’s described in http://www.anujchaudhary.com/2013/05/automated-website-testing-with.html

Enjoy!