Hello,

I've been trying to debug some network issues of a .NET WinForms-based application, but when the "Decrypt HTTPS traffic" option is enabled in Fiddler (screenshot1), I always experience issues with the application (screenshot2). The "Decrypt HTTPS traffic" is working for HTTPS traffic handled by web-browsers, but it does not work at all with this Windows program, despite the fact that the "response header" to CONNECT <removed>:443 HTTP/1.1 is

HTTP/1.1 200 Connection Established
Misc: Proxy-Agent: IWSS

Is there any way to decrypt HTTPS traffic generated by applications other than web-browsers?
I guess that the issue may be related to some conflict with the corporate firewall Trend Micro InterScan Web Security Suite (IWSS), but I'd appreciate some ideas / advices.

Thanks,
Salvatore

Hi 

First of all let me make it more clear. "Fiddler is the one and only, by far the best." (Though I wish it was available on macOS too!)

TBH I'm so new to web debugging. Just having a problem using Fiddler. So let me try to be brief and clear.

 

I'm visiting a website almost everyday. After logging in, the browser try to send a dynamic long GET request including lots of random characters in its URL.

Nothing to do with the request because the response is the key. Actually, the responds contains a text and I'm going to just eliminate few characters before the response being received by the browser. That's all!

 

As you can see, it can be done manually but it's so time consuming to do each and every time every hour.

To do that auto, I'm dealing with 2 main problem. First, having no idea how to detect those long random GET requests to Fiddler to make a breakpoint after them and also no idea how to tell Fiddler to try to eliminate the last 10 characters of their response.

I did my best to be clear. Let me know please if it's not. I really need some kind of help.

Thank you.

 

It works fine on a android 5.1.1 once I installed the root certificate issued by fiddler.

But seems the certificate doesn't work any more with Android 7 and IOs 13.

Fiddler keeps saying the connection is not in private even I have installed the certificate when I tried access any https website(for example:https://freematch.date)

any tricks here? or it is impossible?

thanks for your time.

My client's developer sent me a Postman Post Request Body in a format that I'm not sure how to enter into Fiddler 4.

In the Postman Body (raw):

{
              "userCredential":
              {
                             "userId": "myemail80@mailhost.com",
                             "password": "Password1"
              }
}

I copied just the UserId and password parts into the top part of Fiddler composer, and other values in the lower "Request Body" in Telerik:

userId: myemail80@mailhost.com
password: Password1

Do I need to encode "userCredential" and if so, how?

I am a bit confused between terminologies Request Body and Request Header between Postman and Telerik.

Testing using Postman I get a OK 200 return. In Fiddler I am getting 
"statusCode":1,"errorType":3,"errorCode":9200,"errorMessage":"Missing mandatory data in header"}}

Thanks,

 

Hello, I am trying to use FiddlerScript to change a json response from my API server to my client. I keep on getting an error when I have my client connect to the server. I am new to FiddlerScript so I don't know if I am doing anything wrong.

This is the code I am using in Fiddler ScriptEditor:

I have attached screenshots of the setup and the error codes. 

I test mobile applications on both Android and iOS. I've tried using Fiddler running on a desktop PC to monitor an Android phone's network connections.

Can Fiddler running on a desktop PC be used not only to monitor an Android's or iPhone's network connections, but to throttle (slow down the speed, in a controlled manner) the mobile device's network connections? If so, how?

 

Thank you.

- Russell Johnson
  Software Tester

Hi, 

 

I'm using Fiddler4 to capture from an iOS 13.3.1 device, with the iOS device set to Manual Proxy mode and necessary certificates installed on both end.  Overall, works very well. 

 

But there is a problem.   For every socket opened by the iOS that goes via the proxy is never closed again.   So the connection from iOS to Fiddler4 appears to be closed ok.  However the socket from Fiddler4 to destination device stays open until I shutdown Fiddler. 

 

 

The result of this is that on connection limited devices, they run out of available connections and it all stops working. 

 

I've wiresharked the session when not going via Fiddler and iOS is correctly closing the socket (FIN state is sent).

When I wireshark the Fiddler4 proxied session the socket just stays open based on the socket is open from between my PC running Fiddler and the destination device. 

 

Is this a known problem?  If yes, is there a work around? 

Best regards

 

Steve

 

Hello,

I just downloaded and installed Fiddler on my Ubuntu 16.04 machine (Love it on my Windows machine).  Getting the Fiddler certificate installed for Chrome and Firefox was surprisingly easy (I thought I would have to do some converting).

However, when I try to add the same CER file to the system wide trusted certificates, my OS tells me that the FiddlerRoot.pem does not contain a certificate (output pasted below).  I am wondering if this is a known issue since this is still in beta phase or if I am doing something wrong.

 

I am trying to do this so when I run things through the terminal Fiddler will pick them up - specifically HTTPS requests.

 

output:

test@GPA-HSW04:/usr/lib/mono/4.5$ sudo cp '/home/test/Desktop/FiddlerRoot.cer' '/usr/share/ca-certificates/FiddlerRoot.crt'
test@GPA-HSW04:/usr/lib/mono/4.5$ sudo dpkg-reconfigure ca-certificatesProcessing triggers for ca-certificates (20160104ubuntu1) ...
Updating certificates in /etc/ssl/certs...
WARNING: FiddlerRoot.pem does not contain a certificate or CRL: skipping

Which is the last version of FiddlerCore which is free for commercial use in a non public application?

Earlier I downloaded version 2.4.0.1

Is there any newer version which is free for commercial usage? If yes, from where can I download it?

Hello.  I've got tons of experience using Fiddler but it was on my old Windows 7 machine a couple years ago.  I'm getting back to using Fiddler again, now on a Mac Book Pro, running Mojave.  When I close Fiddler, whether by clicking the close icon on the window or selecting Quit from the menu, it causes my internet to be unusable. I get proxy errors in the browsers.  I've followed directions to reset the proxies in system settings and this changes nothing.  Obviously this is a game-breaking experience.  Is there a solution?