Before I reinstall windows, I used Fiddler Everywhere to capture https normally, but after reinstalling windows, it can't show HTTPS traffic.

I had the same setup with Fiddler Everywhere before reinstalling windows.

The app I'm trying to debug network traffic shows an error when I enter into the app.

Hello,

For the extension I work on it might happen that I need to recognize a HTTP request to a domain that does not exist. However if such a session ends with "HTTP/1.1 502 Fiddler - DNS Lookup Failed" in the Response Header, my extension is not triggered.

Such responses neither trigger the

AutoTamperResponseBefore(Session oSession)

method, nor the

OnPeekAtResponseHeaders(Session oSession)

method. My question is, what can I do here to notice such cases with my extension?

And another question, which other cases should I be aware of that don't cause a proper response?

I have installed and reinstalled fiddler but when I start fiddler I the initial checkup.aspx load in it but then it never gets any more traffic.  I have tried multiple browsers but I never get any traffic.

I'm I missing a setting?

Hello,

I am very new to this program, I was wondering if it were at all possible for fiddler to only monitor traffic of ONE application only.

So that the fiddler only monitors one particular program/excutable, and everything else does NOT go through the proxy?

I tried to use OnBeforeRequest function: listed here - https://docs.telerik.com/fiddler/configure-fiddler/tasks/decrypthttps#skip-traffic-decryption-for-an-application but its still going though the proxy, the proxy is just chosing not to decrypt it, I basically want all to blacklist everything and whitelist X application to go through fiddler, and decrypt the HTTPS.

Hello,

I currently develop a small extension for hobbyist use. The extension reads some information of HTTP traffic between a local application and a server. This works pretty well so far but I stumbled on an issue.

I have two HTTP requests from the application to the server following each other. The first contains the last telemetry and the second requests a result of all previously sent telemetry. Without using Fiddler this works just as expected, but it seems like Fiddler adds enough delay to the first session that the application sends the second request before the server received the first. This sometimes results in the second requests reaching the server to late which means the answer to it from the server is incomplete.

I currently use a workaround by adding a delay to the second session to make it less likely to happen. But I already noticed that even 250ms is not always enough.

public void AutoTamperRequestBefore(Session oSession)
{
    switch (oSession.fullUrl)
    {
        case string s when s == Data.Version.ContractEventsUrl:

            //the first session that needs to reach the server before the second
            //some code
            break;

        case string s when s == Data.Version.ContractEndUrl:
                            
            //the second session that needs to reach the server after the first
            oSession["request-trickle-delay"] = "250";
            break;
    }
}

I noticed that the Session object can be checked if it received a response.

https://www.fiddlerbook.com/om/html/7FE52DC7.htm

I think a good solution would be to put the first session in a variable of the Main class and hold the second session until the first received an answer.

However, I noticed that adding async code to the AutoTamperRequestBefore results in the Session to fire the HTTP request the moment async code is reached. I find nothing about it in the documentation and I don't want to put the Thread to sleep to avoid that.

What can I do?

Greetings, Ben

Hello,

I am using fiddler classic. I want to test a request. The api provider asks me to include 2 headers(request id and signature)

I was able to replace request id in header by placing the below code in onbefore request

if (oSession.oRequest)     
        {  
            {
                oSession.oRequest["Request-Id"] = "New Request id";

                oSession.oRequest["Signature:"] = "New Signature";           

          }    

     }

But I am not able to auto generate md5 hash. How can the auto-generation of md5 hash for request header be achieved?

Thank you.

Regards,

Adam

Hi. Im new to fiddler and I was wondering if its possible to send POST request multiple times with different body everytime, 

specifically, Im sending a pin code in the request and I want to brute force on all possible pin code with 6 digits.

Is it possible?

Thanks!

This is asked before too but it's not working for me.

Hey,

So I wanted to give Fiddler Everywhere a try, but for some Reason Fiddler4 (2?) now refuse to decrypt HTTPs Traffic.

19:50:40:5619 Assembly 'C:\Users\xx\AppData\Local\Programs\Fiddler\CertMaker.dll' was not found. Using default Certificate Generator.
19:50:40:5644 /Fiddler.CertMaker> Using .‰+˜ for certificate generation; UseWildcards=False.
19:50:50:4136 /Fiddler.CertMaker> Failed to identify private key location for Root Certificate. Exception: System.Security.Cryptography.CryptographicException Der Schlüsselsatz ist nicht vorhanden.

It tells me CertMaker.dll is missing,  so he Fallback to Default Generator, but that just post some random rubbish Icons. The Last Error Message is telling me, that he cannot find the Private Key (I installed certificates Multiple Times)

Just Curious if there is a way to fix that issue?