Hey Guys

Long time Telelrik user .. first time fiddler.. lol

I have a strange request from a customer.. I need to replace an existing end point that is receiving xml. But that's as much as the customer knows.

They are offering to redirect traffic they send to the end point, to another ( my) machine.. but since I don't know what they are sending , I don't know how to listen.
What I thought of , can I use fiddler to act as a proxy , and forward the traffic to the proper end point IP and return the responses back to the sender.

I think that is possible to forward the request on using the rules.. what I don't get is how I would handle / capture the response. 

I have requested if I can have the ability to install software on either the client or server to watch, but that does not seem possible. Also asked if they can replicate the network data towards  another machine so I can watch. ( or even plug an old fashioned hub in)

Any ideas / thoughts based on experience would be greatly appreciated.

Rob

Fiddler Script now support C#. I'm try to use HtmlAgilityPack in Fiddler Script by " using HtmlAgilityPack; " . See 1.png;

It shows an error .  See 2.png;

I'm try to change version of HtmlAgilityPack but it still same error.

Could some one help me how to fix this error? Thanks so much.

I successfully saved the request and created a session which I want to reply later using fiddler core and C# code. 

This worked great for some time and than it just stopped probably when nginx was added and turned on the geo IP location.

I did testing with Fiddler 4 UI app and got very strange results when run reply from various PC machines. On most machine it fails with below raw response with error message is:

HTTP/1.1 502 Fiddler - Connection Failed
Date: Thu, 16 Jan 2020 14:20:29 GMT
Content-Type: text/html; charset=UTF-8
Connection: close
Cache-Control: no-cache, must-revalidate
Timestamp: 15:20:29.441

[Fiddler] The connection to 'www.mozzartbet.com' failed.  <br />System.Security.SecurityException Failed to negotiate HTTPS connection with server.fiddler.network.https&gt; HTTPS handshake to www.mozzartbet.com (for #25) failed. System.Security.Authentication.AuthenticationException A call to SSPI failed, see inner exception. &lt; The function requested is not supported

Win32 (SChannel) Native Error Code: 0x80090302 

I have tried Fiddler 4 on AWS machine in cloud and from that one it is still working using system proxy but on test machine when we run testing it is still failing and tried couple more machines same.

I tried than to use Gateway Override and use Manual Proxy Configuration to avoid if there is some IP blocking. I used squied 

Please find attached .saz archive of the saved request which I want to reply (remove .jpg extension by renaming the file and file type should be .saz).

 

 

 

 

I was working with a user who has no Admin rights.  When she was enabling HTTPS decrypt, it went through the warning-accept-cert process.  It failed with

ShellExecute Failed

Fiddler Exception thrown... This program is blocked by group policy....

 

Can I get a hint as to what program Fiddler runs as part of the HTTPS decrypt-enable process?  Then I can set about defeating the GPO.

Fiddler is failing set up the system proxy.

 

This is what the log says:

11:37:30:6321 Fiddler Running...
11:37:30:6321 Fiddler was unable to get information about the proxy for 'DefaultLAN' [0x2f92].

11:37:30:6321 !WARNING: Failed to get proxy information for Connection 'DefaultLAN'.
11:37:30:6321 Setting upstream gateway to none
11:37:30:6351 Windows 8+ AppContainer isolation feature detected.

 

I also tried to manually change the proxy settings from inetcpl.cpl. but when I try to click "OK" in the "LAN Settings" dialog, nothing happens. The "Cancel" button does work though.

I need to see what I'm sending to a SalesForce endpoint, but so far, nothing I've done works.

 

How to?

 

Thanks

Phil

i have a issue where my fiddler stops capturing calls when i connect to my vpn!!The issue is ,
Whenever i connect to VPN, i have to change

If i turn off the automatic configuration script, my fiddler works, but my internet fails. Since all my Rest calls are internet based, everything returs 502
. and my Proxy server configuration has


any help you would be great!!!

When I click "WinConfig" then the "Refresh" button, an error pops up.

This is the system information in About menu.

v5.0.20194.41348 for .NET 4.6.1
Built: Oct 3/2019

64-bit AMD64, VM: 65.0mb, WS: 116.0mb
.NET 4.7.1 WinNT 10.0.18362.0

If a site uses, for example, a <script src=... then I want to catch that script and modify it.

I choose Unlock for editing and modify it, but I've noticed when I click Replay/Reissue the browser's console still shows only the original Response.

Meanwhile, Fiddler does show the new modified request being sent.

So what does it mean?

Hi,

I want to modify the response body value which is stream, but failed.

The stream value is just like MP4, the ascii of head data is "00 00 00 20 66 74 79 70 69 73 6F 6D...".

And I planed to modify them to "FE FE FE FE FE FE FE ....". But when I check the sent data, I found them were changed to "C3 BE C3 BE C3 BE C3 BE C3 BE C3 BE ..."

The following is my JScript code:

var oBody;
oBody = "\xfe\xfe\xfe\xfe\xfe\xfe\xfe\xfe\xfe\xfe\xfe\xfe\xfe\xfe\xfe\xfe\xfe\xfe\xfe\xfe\xfe\xfe\xfe\xfe\xfe";
oSession.utilReplaceRegexInResponse("ftypisom.*",oBody);

// oSession.utilSetResponseBody(oBody);                    // I tried this but failed too...

How could I set response body to any ascii.

Thanks :)