I user fiddler classic as proxy and it works well.

i try to use it to access https://link.springer.com/ iget this:

System.Security.SecurityException Failed to negotiate HTTPS connection with server.fiddler.network.https> HTTPS handshake to link.springer.com

This is because fiddler classic does not yet support tls 1.3. When will fiddler classic be updated to support tls1.3?

thanks so much!

In the CONNECT response frame, we have the "Client Certificate" so we know there was a CERTIFICATE REQUEST made by the server as part of its SERVER HELLO response. What I would like to know is what DN(s)/CN(s) the server sent down with the CERTIFICATE REQUEST. I have not been able to find any references to pull this out of the SERVER HELLO response.

When I use fiddler classic, response from https://ok.ru on my last laptop (Lenovo Legion Y520 Win11) is normal, but my new laptop (Asus ROG Strig G17 Win11) - have a problem with decode.

Error from Fiddler:

See the end of this message for details on invoking 
just-in-time (JIT) debugging instead of this dialog box.

************** Exception Text **************
System.Exception: Brotli conversion failed
   at Fiddler.Utilities.BrotliExpand(Byte[] arrIn) in C:\Jenkins\Fiddler_Windows\workspace\FiddlerCore\FiddlerCore.Shared\Common\Core\Utilities.cs:line 2796
   at Standard.Transformer.Expand(ExpanderDelegate eD, Boolean bUpdateSizeLabel)
   at Standard.Transformer.doRaw(Boolean bUpdateSizeLabel)
   at System.Windows.Forms.Control.OnClick(EventArgs e)
   at System.Windows.Forms.RadioButton.OnMouseUp(MouseEventArgs mevent)
   at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ButtonBase.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)


************** Loaded Assemblies **************
mscorlib
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.9093.0 built by: NET481REL1LAST_C
    CodeBase: file:///C:/Windows/Microsoft.NET/Framework64/v4.0.30319/mscorlib.dll
----------------------------------------
Fiddler
    Assembly Version: 5.0.20211.51073
    Win32 Version: 5.0.20211.51073
    CodeBase: file:///C:/Users/valdi/AppData/Local/Programs/Fiddler/Fiddler.exe
----------------------------------------
System
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.9093.0 built by: NET481REL1LAST_C
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System/v4.0_4.0.0.0__b77a5c561934e089/System.dll
----------------------------------------
System.Core
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.9093.0 built by: NET481REL1LAST_C
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Core/v4.0_4.0.0.0__b77a5c561934e089/System.Core.dll
----------------------------------------
System.Windows.Forms
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.9093.0 built by: NET481REL1LAST_C
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Windows.Forms/v4.0_4.0.0.0__b77a5c561934e089/System.Windows.Forms.dll
----------------------------------------
System.Drawing
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.9037.0 built by: NET481REL1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Drawing/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll
----------------------------------------
System.Configuration
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.9037.0 built by: NET481REL1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Configuration/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Configuration.dll
----------------------------------------
System.Xml
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.9037.0 built by: NET481REL1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Xml/v4.0_4.0.0.0__b77a5c561934e089/System.Xml.dll
----------------------------------------
Analytics
    Assembly Version: 1.0.20182.27266
    Win32 Version: 1.0.20182.27266
    CodeBase: file:///C:/Users/valdi/AppData/Local/Programs/Fiddler/Analytics.DLL
----------------------------------------
Microsoft.GeneratedCode
    Assembly Version: 1.0.0.0
    Win32 Version: 4.8.9037.0 built by: NET481REL1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Xml/v4.0_4.0.0.0__b77a5c561934e089/System.Xml.dll
----------------------------------------
System.ComponentModel.Composition
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.9037.0
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.ComponentModel.Composition/v4.0_4.0.0.0__b77a5c561934e089/System.ComponentModel.Composition.dll
----------------------------------------
Telerik.NetworkConnections
    Assembly Version: 0.1.2.0
    Win32 Version: 0.1.2.0
    CodeBase: file:///C:/Users/valdi/AppData/Local/Programs/Fiddler/Telerik.NetworkConnections.DLL
----------------------------------------
Telerik.NetworkConnections.Windows
    Assembly Version: 0.1.2.0
    Win32 Version: 0.1.2.0
    CodeBase: file:///C:/USERS/VALDI/APPDATA/LOCAL/PROGRAMS/FIDDLER/PLUGINS/NETWORKCONNECTIONS/TELERIK.NETWORKCONNECTIONS.WINDOWS.DLL
----------------------------------------
MetadataViewProxies_13e3577d-0d9f-40cf-b9db-c5eff2edd807
    Assembly Version: 0.0.0.0
    Win32 Version: 4.8.9037.0
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.ComponentModel.Composition/v4.0_4.0.0.0__b77a5c561934e089/System.ComponentModel.Composition.dll
----------------------------------------
Standard
    Assembly Version: 2.6.2.0
    Win32 Version: 2.6.2.0
    CodeBase: file:///C:/Users/valdi/AppData/Local/Programs/Fiddler/Inspectors/Standard.dll
----------------------------------------
SyntaxView
    Assembly Version: 2.6.2.0
    Win32 Version: 2.6.2.0
    CodeBase: file:///C:/Users/valdi/AppData/Local/Programs/Fiddler/Inspectors/SyntaxView.dll
----------------------------------------
FiddlerOrchestra.Addon
    Assembly Version: 1.0.20202.16135
    Win32 Version: 1.0.20202.16135
    CodeBase: file:///C:/Users/valdi/AppData/Local/Programs/Fiddler/Scripts/FiddlerOrchestra.Addon.dll
----------------------------------------
FiddlerOrchestra.Connection
    Assembly Version: 1.0.20202.16135
    Win32 Version: 1.0.20202.16135
    CodeBase: file:///C:/Users/valdi/AppData/Local/Programs/Fiddler/Scripts/FiddlerOrchestra.Connection.dll
----------------------------------------
netstandard
    Assembly Version: 2.0.0.0
    Win32 Version: 4.8.9037.0
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/netstandard/v4.0_2.0.0.0__cc7b13ffcd2ddd51/netstandard.dll
----------------------------------------
FiddlerOrchestra.Protocol
    Assembly Version: 1.0.20202.16135
    Win32 Version: 1.0.20202.16135
    CodeBase: file:///C:/Users/valdi/AppData/Local/Programs/Fiddler/Scripts/FiddlerOrchestra.Protocol.dll
----------------------------------------
FiddlerOrchestra.Utilities
    Assembly Version: 1.0.20202.16135
    Win32 Version: 1.0.20202.16135
    CodeBase: file:///C:/Users/valdi/AppData/Local/Programs/Fiddler/Scripts/FiddlerOrchestra.Utilities.dll
----------------------------------------
RulesTab2
    Assembly Version: 2.6.2.0
    Win32 Version: 2.6.2.0
    CodeBase: file:///C:/Users/valdi/AppData/Local/Programs/Fiddler/Scripts/RulesTab2.dll
----------------------------------------
SimpleFilter
    Assembly Version: 2.6.2.0
    Win32 Version: 2.6.2.0
    CodeBase: file:///C:/Users/valdi/AppData/Local/Programs/Fiddler/Scripts/SimpleFilter.dll
----------------------------------------
Timeline
    Assembly Version: 2.6.0.3
    Win32 Version: 2.6.0.3
    CodeBase: file:///C:/Users/valdi/AppData/Local/Programs/Fiddler/Scripts/Timeline.dll
----------------------------------------
Microsoft.JScript
    Assembly Version: 10.0.0.0
    Win32 Version: 14.8.9037.0 built by: NET481REL1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/Microsoft.JScript/v4.0_10.0.0.0__b03f5f7f11d50a3a/Microsoft.JScript.dll
----------------------------------------
System.Windows
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.9037.0
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Windows/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Windows.dll
----------------------------------------
JScript Thunk Assembly
    Assembly Version: 0.0.0.0
    Win32 Version: 14.8.9037.0 built by: NET481REL1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/Microsoft.JScript/v4.0_10.0.0.0__b03f5f7f11d50a3a/Microsoft.JScript.dll
----------------------------------------
Accessibility
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.9037.0 built by: NET481REL1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/Accessibility/v4.0_4.0.0.0__b03f5f7f11d50a3a/Accessibility.dll
----------------------------------------
W2uBEJRg
    Assembly Version: 0.0.0.0
    Win32 Version: 14.8.9037.0 built by: NET481REL1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/Microsoft.JScript/v4.0_10.0.0.0__b03f5f7f11d50a3a/Microsoft.JScript.dll
----------------------------------------
Microsoft.GeneratedCode
    Assembly Version: 1.0.0.0
    Win32 Version: 4.8.9037.0 built by: NET481REL1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Xml/v4.0_4.0.0.0__b77a5c561934e089/System.Xml.dll
----------------------------------------
GA.Analytics.Monitor
    Assembly Version: 1.0.20182.27266
    Win32 Version: 1.0.20182.27266
    CodeBase: file:///C:/Users/valdi/AppData/Local/Programs/Fiddler/GA.Analytics.Monitor.DLL
----------------------------------------
System.Net.Http
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.9037.0 built by: NET481REL1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Net.Http/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Net.Http.dll
----------------------------------------
System.Security
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.9037.0 built by: NET481REL1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Security/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Security.dll
----------------------------------------
Newtonsoft.Json
    Assembly Version: 11.0.0.0
    Win32 Version: 11.0.2.21924
    CodeBase: file:///C:/Users/valdi/AppData/Local/Programs/Fiddler/Newtonsoft.Json.DLL
----------------------------------------
System.Numerics
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.9037.0 built by: NET481REL1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Numerics/v4.0_4.0.0.0__b77a5c561934e089/System.Numerics.dll
----------------------------------------
System.Runtime.Serialization
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.9037.0 built by: NET481REL1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Runtime.Serialization/v4.0_4.0.0.0__b77a5c561934e089/System.Runtime.Serialization.dll
----------------------------------------
System.Data
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.9093.0 built by: NET481REL1LAST_C
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_64/System.Data/v4.0_4.0.0.0__b77a5c561934e089/System.Data.dll
----------------------------------------
Microsoft.mshtml
    Assembly Version: 7.0.3300.0
    Win32 Version: 7.0.3300.0
    CodeBase: file:///C:/WINDOWS/assembly/GAC/Microsoft.mshtml/7.0.3300.0__b03f5f7f11d50a3a/Microsoft.mshtml.dll
----------------------------------------
System.Web
    Assembly Version: 4.0.0.0
    Win32 Version: 4.8.9037.0 built by: NET481REL1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_64/System.Web/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Web.dll
----------------------------------------

************** JIT Debugging **************
To enable just-in-time (JIT) debugging, the .config file for this
application or computer (machine.config) must have the
jitDebugging value set in the system.windows.forms section.
The application must also be compiled with debugging
enabled.

For example:

<configuration>
    <system.windows.forms jitDebugging="true" />
</configuration>

When JIT debugging is enabled, any unhandled exception
will be sent to the JIT debugger registered on the computer
rather than be handled by this dialog box.

Click here don`t help me 

My settings

I check test version Fiddler Everywhere, and error have here.

There's a 3rd party ios app that i want to capture traffic from, and i'm not having any luck in doing so.  It is specifically the Twinkly app.  My web requests from the browser seem to be getting decoded and i did not expect the apple apps to be decoded, due to certificate pinning, but I really would like to get this working for a 3rd party app.  I installed a bouncy castle certificate and tried that, and I also set up a trial of Fiddler Everywhere and started over, with no luck.  Any ideas?  I am willing to jump through any kind of hoop necessary to get this to work, including jailbreaking the phone.

Hi,

I tried

static function OnBeforeRequest(oSession: Session) {
var arr: Byte[] = oSession.requestBodyBytes;
var istr: String = '';
istr =  Convert.ToBase64String(arr);

// ... do something with request body ...

oSession.RequestHeaders['Fiddler-Encoding'] = 'base64';
oSession.utilSetRequestBody(istr);
}

base on this article. Unfortunately this does not work. Any help appreciated.

I can capture traffic, decrypt HTTPs from web browsers and other applications with Fiddler just fine.

But with this app, Fiddler doesn't see anything. Tried options like adding protocols,  checking ignore cert errors, even tried tried turning off HTTPS decryption. No difference, just nothing.

With Wireshark. I can see the SSL/TCP traffic.

Here's the app link (You can register for free with junk email to login via app)

https://tinyurl.com/4yd3e94r

Please help

HI:

I'm try to use fiddler as reverse proxy ,and i Write a FiddlerScript Rule like this

if (oSession.host.toLowerCase() == "192.168.5.201:8889") oSession.host = "pubs.acs.org";

then i try access https://192.168.5.201:8889 , I get this:

 i know this is because cloudflare detective it as a ddos attack.

Does it possible to solve this problem?

In Fiddler Classic decryption I set <client> and tls 1.2, I'm capturing traffic from mobile application via Fiddler proxy working in local network on Win 10 machine,

but still B2C in Safari shows me message "This Connection Is Not Private", and says it shows this because site uses tls 1.0 and tls 1.1;

is it solvable?

In the beginning I had only tokens: <client>; ssl3; tls1.0; tls1.1 - but then I added 1.2, should have I reissue certificates ?? (suppose that not)

What can be the issue?

Thank you much.