Unplanned
Last Updated: 04 Jun 2020 14:23 by Aaron
Aaron
Created on: 01 Jun 2020 21:04
Type: Bug Report
1
Fiddler Everywhere (v0.10.0) not working with Android Emulator

Latest version of Fiddler (v0.10.0) and Android Emulator is not proxying the connections properly.

I have Fiddler Everywhere running and know it is working when I can send requests through Postman and see them show up in Fiddler properly.

However, if I set up the Android Emulator through Android Studio, and set the proxy to be Fiddler, connections do not fully reach the backend service I am sending requests to. All that shows up in Fiddler is

REQUEST

CONNECT 192.168.5.7:5000 HTTP/1.1
Host: 192.168.5.7:5000

RESPONSE

HTTP/1.1 200 Connection Established
FiddlerGateway: Direct
StartTime: 16:12:05.141
Connection: close

The service is running on my local host machine (192.168.5.7) on port 5000.

If I close Fiddler and run charles-proxy, then set the Android Emulator to use that as the proxy, I see the full request, my service responds, and I see the response in Charles.

5 comments
Aaron
Posted on: 04 Jun 2020 14:23
Just know that I am NOT trying to use HTTPS in my instance, so both Igors and I are experiencing the problem with both HTTPS and non-HTTPS.
Igors
Posted on: 04 Jun 2020 12:55

Hey Nick. 

 

Good to hear that y'all are looking at it. 

 

I did some more digging and here's the gist: 

Since Android 7 (N) each app can specify which root certificates it allows.  

 

So unless you're testing the app that you build and can modify the security manifest file to allow the Fiddler root cert, your only option is to add that manifest to the apk file.  

Adding it to the apk is fiddly, and doesn't work well (at least with the tools currently available).

 

But if y'all could figure a way to make this work, it would increase the value proposition of Fiddler by a thousand fold.

ADMIN
Nick Iliev
Posted on: 04 Jun 2020 10:52

Hello Aaron,

 

I've added the provided additional information in our internal issue - once again thank you for providing the feedback and the details.

 

Regards,
Nick Iliev
Progress Telerik

Progress is here for your business, like always. Read more about the measures we are taking to ensure business continuity and help fight the COVID-19 pandemic.
Our thoughts here at Progress are with those affected by the outbreak.
Igors
Posted on: 03 Jun 2020 11:38

@Nick Iliev

This actually goes way deeper. I was about to write a report on it. 


This problem is present on Fiddler for Windows (latest), 0.5.0, 0.10 . Same problem on all 3 operating systems. 

Tried multiple phones, multiple router configs and etc.  

 

Every single time, CONNECT requests get a response and no data is sent afterwards with mobile apps. 

 

This happens only when you try to Decrypt HTTPS traffic.

ADMIN
Nick Iliev
Posted on: 02 Jun 2020 07:52

Hello Aaron,

 

Thank you for the detailed explanation of your issue! I've tested the scenario on my side and can confirm that setting a manual proxy, as shown in this blog post (but while using port 8866 for Fiddler Everywhere), is not working and causing the same behavior as the one you described. Marking the issue as a bug to be planned and fixed. I will update this thread with related information as soon as we have more insights on the matter.

 

Regards,
Nick Iliev
Progress Telerik

Progress is here for your business, like always. Read more about the measures we are taking to ensure business continuity and help fight the COVID-19 pandemic.
Our thoughts here at Progress are with those affected by the outbreak.