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6 answers
222 views
hi,

I'm using ec2 instance (with putty), connected to US proxy.
When I'm using fiddler, my IP is changing to local IP and I can't get the site content I want to monitor (which will be presented only for US proxy).

When unchecking "act as system proxy on startup" in connection settings, fiddler doesn't monitor anything, also I can't change my browsers LAN settings as putty connection won't work.

I need a solution in order to monitor all HTTP traffic without loosing my IP (given by ec2 instance proxy).
Thanks in advance,
Eyal.
Eric R | Senior Technical Support Engineer
Telerik team
 answered on 24 Sep 2019
1 answer
1.0K+ views

Hello,

I need Fiddler, acting as a permanent proxy, to catch requests for a specific host, and add a Referer Header to each of these requests. How this can be implemented?

Thanks a lot.

Kammen
Telerik team
 answered on 24 Sep 2019
6 answers
321 views

Hi,

I've developed an Fiddler extension (MockingBird) and would like to submit it to Telerik to list it on Extension page which I think will help others because any user of the producer will certainly to go company's forum/website for help. Below is the link to my extension:

https://github.com/hemantsharma-io/MockingBird

The interesting idea is to convert a Fiddler session to any other text format and use it further in another favorite tool for debugging/analysis with a simple mustache template e.g. i've created a template to convert Fiddler session to JMX test plan with just a drag-n-drop. More templates can be added locally for specific use cases.

I'm open to add/update detail in repo's wiki if required.

Thanks,

Hemant

Kammen
Telerik team
 answered on 24 Sep 2019
1 answer
425 views

Hello,

 

I am trying to use the .NET Standard beta of fiddlercore. A very simple test application results in the following error:

 

```

Unhandled Exception: System.ComponentModel.Composition.ImportCardinalityMismatchException: No exports were found that match the constraint:
        ContractName    Telerik.NetworkConnections.NetworkConnectionsManager
        RequiredTypeIdentity    Telerik.NetworkConnections.NetworkConnectionsManager
   at System.ComponentModel.Composition.Hosting.ExportProvider.GetExports(ImportDefinition definition, AtomicComposition atomicComposition)
   at Fiddler.Proxy..ctor(Boolean , ProxySettings ) in C:\JenkinsHome\jobs\FiddlerCoreForNetStandardReleaseBuild\workspace\Fiddler2\Common\Core\Proxy.cs:line 208
   at Fiddler.FiddlerApplication.Startup(FiddlerCoreStartupSettings startupSettings) in C:\JenkinsHome\jobs\FiddlerCoreForNetStandardReleaseBuild\workspace\Fiddler2\Common\FiddlerApplication.cs:line 732

```

 

I have added all the FiddlerCore nuget packages and ensured that Telerik.NetworkConnections.dll and Telerik.NetworkConnections.Windows.dll are present in the application directory. I also have cleared the ComponentCache for Visual Studio.

 

Please advise.

 

Kind regards

Simeon
Telerik team
 answered on 23 Sep 2019
3 answers
177 views
---------------------------
Uncaught Exception in Session #35
---------------------------
Fiddler has encountered an unexpected problem. If you believe this is a bug in Fiddler, please copy this message by hitting CTRL+C, and submit a bug report at http://www.telerik.com/forums/fiddler.

Cannot access a disposed object.

Object name: 'WinHttpAutoProxy'.

Type: System.ObjectDisposedException
Source: Fiddler
   at “.Ÿœ.ƒ•(String •, String& ‘‰, String& ”) in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\FiddlerCore\PlatformExtensions\Windows\FiddlerCore.PlatformExtensions.Windows.Shared\WinHttpAutoProxy.cs:line 52

   at .‚•.œ(String –, IPEndPoint& žœ) in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\AutoProxy.cs:line 142

   at Fiddler.Proxy.FindGatewayForOrigin(String sURIScheme, String sHostAndPort) in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\Proxy.cs:line 808

   at Fiddler.ServerChatter.Œ() in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\ServerChatter.cs:line 1056

   at Fiddler.Session.‘() in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\Session.cs:line 3725

   at Fiddler.Session.(Object ) in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\Session.cs:line 3500


Fiddler v5.0.20182.28034 (x64 AMD64) [.NET 4.0.30319.42000 on Microsoft Windows NT 6.1.7601 Service Pack 1] 
---------------------------
确定   
---------------------------
Eric R | Senior Technical Support Engineer
Telerik team
 answered on 19 Sep 2019
1 answer
166 views
Hello,

I would like to know if I can code a dll to autoresponder without running Fiddler or having Fiddler installed on the PC

so when I run it then will stop change the url to another url

Thank you.
Eric R | Senior Technical Support Engineer
Telerik team
 answered on 18 Sep 2019
0 answers
169 views

     Hi,

I am trying to invoke the execaction from powershell script. Is there any reference document for the valid commands for the same? I would like to export html, xml and .saz reports.

 

Many thanks.

amrita
Top achievements
Rank 1
 asked on 18 Sep 2019
2 answers
1.2K+ views
When I try to run FiddleApplication.Startup(startupConfig)

FiddlerCoreStartupSettings startupSettings = newFiddlerCoreStartupSettingsBuilder() .ListenOnPort(0) .RegisterAsSystemProxy() .DecryptSSL() .Build(); FiddlerApplication.Startup(startupSettings);

In my log events I see:

Starting FiddlerCore/4.6.20191.7809 ...
** LogString: !WARNING: The DefaultLAN Gateway information could not be obtained.
** NotifyUser: Error - Failed to register Fiddler as the system proxy.


I'm running the process as administrator.

Note: When I run the normal Fiddler UI application everything works fine. Even running an older FiddlerCore version (2.3) is able to register itself as the system proxy.


P.S - I also see a warning in Visual Studio - "Please use Telerik.NetworkConnections.NetworkConnectionsManager to register the FiddlerCore Proxy as the system proxy." But I couldn't find any documentation/examples using NetworkConnectionsManager and I couldn't figure out how to use it.
fiddlercore fiddler-dev
Eric R | Senior Technical Support Engineer
Telerik team
 answered on 12 Sep 2019
8 answers
1.5K+ views
I have Fiddler setup as a reverse proxy to capture request and responses from my app. While my app is working, it's not capturing any requests and response, and I'm getting these errors in my fiddler log. I tried CertEnroll and MakeCert but both throw different errors.

I tried searching for this error and I read this article but I don't know what the issue is:
https://www.telerik.com/blogs/faq---certificates-in-fiddler

How can I fix these errors so Fiddler can capture my requests and responses in my app?

-= Fiddler Event Log =-
See http://fiddler2.com/r/?FiddlerLog for details.

15:13:46:5212 Fiddler Running...
15:13:46:5592 !WARNING Fiddler has detected that Chrome GPO specifies proxy configuration 'system'.
15:13:54:5022 /Fiddler.CertMaker> Using Fiddler.DefaultCertificateProvider+CertEnrollEngine for certificate generation
15:13:54:5252 /Fiddler.CertMaker> Failed to identify private key location for Root Certificate. Exception: System.NullReferenceException Object reference not set to an instance of an object.
15:13:54:5272 /Fiddler.CertMaker> Invoking CertEnroll for arguments: CN=doesitmatter.com, O=DO_NOT_TRUST, OU=Created by http://www.fiddler2.com
15:13:54:8502 !ERROR: Failed to generate Certificate using CertEnroll. System.Reflection.TargetInvocationException Exception has been thrown by the target of an invocation. < CertEnroll::CSignerCertificate::Initialize: The certificate does not have a property that references a private key. 0x8009200a (-2146885622)
15:13:54:8502 /Fiddler.CertMaker> Failed to identify private key location for Root Certificate. Exception: System.NullReferenceException Object reference not set to an instance of an object.
15:13:54:8502 !Fiddler.CertMaker> Tried to create cert for doesitmatter.com, but can't find it from thread 10!
15:13:54:8512 fiddler.https> Failed to obtain certificate for doesitmatter.com due to Certificate Maker returned null when asked for a certificate for doesitmatter.com
15:13:59:8712 /Fiddler.CertMaker> Invoking CertEnroll for arguments: CN=some-url.com, O=DO_NOT_TRUST, OU=Created by http://www.fiddler2.com
15:13:59:8712 /Fiddler.CertMaker> Reusing PrivateKey for new certificate.
15:13:59:8812 !ERROR: Failed to generate Certificate using CertEnroll. System.Reflection.TargetInvocationException Exception has been thrown by the target of an invocation. < CertEnroll::CSignerCertificate::Initialize: The certificate does not have a property that references a private key. 0x8009200a (-2146885622)
15:13:59:8812 /Fiddler.CertMaker> Failed to identify private key location for Root Certificate. Exception: System.NullReferenceException Object reference not set to an instance of an object.
15:13:59:8812 !Fiddler.CertMaker> Tried to create cert for some-url.com, but can't find it from thread 13!
15:13:59:8812 fiddler.https> Failed to obtain certificate for some-url.com due to Certificate Maker returned null when asked for a certificate for some-url.com


When I use makeCert:


-= Fiddler Event Log =-
See http://fiddler2.com/r/?FiddlerLog for details.

17:27:43:2012 Fiddler Running...
17:27:43:2322 !WARNING Fiddler has detected that Chrome GPO specifies proxy configuration 'system'.
17:27:48:1422 /Fiddler.CertMaker> Using Fiddler.DefaultCertificateProvider+MakeCertEngine for certificate generation
17:27:48:1652 /Fiddler.CertMaker> Failed to identify private key location for Root Certificate. Exception: System.NullReferenceException Object reference not set to an instance of an object.
17:27:48:1682 /Fiddler.CertMaker> Invoking makecert.exe with arguments: -pe -ss my -n "CN=something.com, O=DO_NOT_TRUST, OU=Created by http://www.fiddler2.com" -sky exchange -in DO_NOT_TRUST_FiddlerRoot -is my -eku 1.3.6.1.5.5.7.3.1 -cy end -a sha256 -m 132 -b 09/04/2018
17:27:48:8222 /Fiddler.CertMaker>11-CreateCert(something.com) => (-1)
Results from C:\Program Files (x86)\Fiddler2\MakeCert.exe -pe -ss my -n "CN=something.com, O=DO_NOT_TRUST, OU=Created by http://www.fiddler2.com" -sky exchange -in DO_NOT_TRUST_FiddlerRoot -is my -eku 1.3.6.1.5.5.7.3.1 -cy end -a sha256 -m 132 -b 09/04/2018

Error: Fail to acquire a security provider from the issuer's certificate
Failed
-------------------------------------------

17:27:48:8222 Fiddler.CertMaker> [C:\Program Files (x86)\Fiddler2\MakeCert.exe -pe -ss my -n "CN=something.com, O=DO_NOT_TRUST, OU=Created by http://www.fiddler2.com" -sky exchange -in DO_NOT_TRUST_FiddlerRoot -is my -eku 1.3.6.1.5.5.7.3.1 -cy end -a sha256 -m 132 -b 09/04/2018 ] Returned Error: Creation of the interception certificate failed.

makecert.exe returned -1.

Results from C:\Program Files (x86)\Fiddler2\MakeCert.exe -pe -ss my -n "CN=something.com, O=DO_NOT_TRUST, OU=Created by http://www.fiddler2.com" -sky exchange -in DO_NOT_TRUST_FiddlerRoot -is my -eku 1.3.6.1.5.5.7.3.1 -cy end -a sha256 -m 132 -b 09/04/2018

Error: Fail to acquire a security provider from the issuer's certificate
Failed
-------------------------------------------
Eric R | Senior Technical Support Engineer
Telerik team
 answered on 12 Sep 2019
2 answers
262 views
There are lots of indicators for online/offline status in UI and log. But how do we check this in fiddlerscript (c#)? (The application does not call any of OnPeekAtResponseHeaders(), OnBeforeResponse() and OnReturningError() when I am offline)
Eric R | Senior Technical Support Engineer
Telerik team
 answered on 10 Sep 2019
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