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
-------------------------------------------

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)

Hi,

since my company brought in a new corporate proxy (IBoss) I am unable to use Fiddler.

Any ideas please? The error I receive is "The system proxy was changed. Click to reenable Telerik Fiddler capture".

From some googling I am guessing that IBoss proxy is changing settings as soon as Fiddler makes a change.

In IE, I do not have any entries in Internet Options -> LAN Settings -> Proxy Settings (and these settings are now blank & disabled).  There is an automatic config script.

If I use foxy proxy to change proxy to localhost and give a port, I can capture local traffic but nothing external (ie anything that should go though IBoss). Have tried several Gateway options in Fiddler but unsure what Fiddler needs.

Any thoughts please?

Dan

 

 

Hello, the situation is that I am testing a controller from this application, I am working with an api, asp.net core and entity frame, the thing is that I do not connect the vue.js with the asp, so I am testing the controller from this application.

I have been trying to send the data to the controller but it gives me a data error in the "idUsuario" section =   {"errors":{"":["Error converting value \"IdUsuario\" to type 'SMAD_WEB.Modelos.UsuarioModelo.UsuarioViewModel'. Path '', line 1, position 12."]},"title":"One or more validation errors occurred.","status":400,"traceId":"80000166-0006-ff00-b63f-84710c7967bb"}

all the gesture, controller, model, and data, is in int, but at the time of sending it, it tells me that it cannot connect it

 

"IdUsuario" : 504100637,
" NomUsuario ": "wilberth",
"' EmailUsuario "' : "wil@gmail.com",
"contrasena" : "1234"
"Rol": 1 

 

In this way I send it, will it be that it is badly sent, can anyone tell me how to save it?

Hi,Eric 

I have a problem, someone has the same problem as me before, here,but there is no reply, and it has been a long time, so I want to bring up this problem again.

I want to use PAC file. http://127.0.0.1:8888/proxy.pac, this way, if my proxy accidently quits without remove the proxy setting, the browser will be able to continue to work since it can't find the pac file, thus consider it "No proxy".

But When I set the flags, if I don't include: "RegisterAsSystemProxy", the PAC file will not registered.
If I DO include "RegisterAsSystemProxy", the PAC file is registered, but also the proxy servers, 127.0.0.1 8888 for http and https. What's the point to have both registered, and it negate my purpose.
Anyway to hook up PAC file only?

Did I miss something?

Hi, while trialing out Fiddler to specifically look at HTTPs traffic on a MacBook pro (10.14.6) I got a crash of Mono Fiddler.

Since then I can't get HTTP or HTTPS traffic working on my machine in any browser (Safari, Chrome, FireFox and Opera).

I double checked the proxy settings for http and https and confirm they are turned off (when enabled, I get a proxy timeout).

Traffic in a webbrowser just times out, eventually giving an error time out.

Using netstat -nr I see normal routes and I can ping a domain without any issues (dns resolution and icmp succeeds).

Hi there long time Fiddler user first time poster

I have a capture which I done in wireshark some time ago it contains http traffic: http://dxing.si/STB/Amino/Project%20Amino%20hack/STB_Power_HTTP_Only.pcapng

 

when going to File->Import seassions->Packet capture and select this pcapng file it says it loaded it but 0 sessions were loaded and nothing shows up

 

if anyone has any idea why this file won't import please suggest how I can convert it to .saz file maybe so fiddler will like it

here is the picture that shows filddler cannot load any sessions: http://dxing.si/STB/fiddler.PNG

Thanks for Anwsering and Best Regards

---------------------------
SAZ Creation Error
---------------------------
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.
The physical file represented by the item could not be created.
Type: Xceed.FileSystem.DiskFile
FullName: C:\Users\jpatel6\Documents\Fiddler2\Captures\SOAPENG_08212019.saz
Type: Xceed.FileSystem.FileSystemException
Source: Xceed.FileSystem.v5.4
   at Xceed.FileSystem.DiskFile.DoCreate(FileSystemEventsSession session)
   at Xceed.FileSystem.AbstractFile.DoCreateWrite(FileSystemEventsSession session, FileShare share)
   at Xceed.FileSystem.AbstractFile.CreateWrite(FileSystemEvents events, Object userData, FileShare share)
   at Xceed.Utils.Storage.Storage.Update(FileSystemEventsSession session)
   at Xceed.Zip.ZipStorage.Update(FileSystemEventsSession session)
   at Xceed.Utils.Storage.StorageHandler.Rebuild(FileSystemEventsSession session)
   at Xceed.Utils.Storage.StorageHandler.ReleaseReference(FileSystemEventsSession session)
   at Xceed.Zip.ZipArchive.EndUpdate(FileSystemEvents events, Object userData)
   at .•.CompleteArchive() in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\SAZ-Xceed.cs:line 310
   at Fiddler.frmViewer.actSaveSessionArchive(String , String , Session[] ) in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Viewer.cs:line 6482
System.IO.IOException: The operation completed successfully.


   at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
   at System.IO.FileSystemInfo.set_Attributes(FileAttributes value)
   at Xceed.FileSystem.DiskFile.DoCreate(FileSystemEventsSession session)
Fiddler v4.6.20171.14978 (x64 AMD64) [.NET 4.0.30319.42000 on Microsoft Windows NT 10.0.14393.0]
---------------------------
OK  
---------------------------

Hey guys! I'm editing some stuff on a website and I wonder if it's possible to run AutoResponder as a launcher or something else because I will release the edit that I'm working on to the public. I don't want people to mess with installing Fiddler and importing the AutoResponder stuff, that would just take too long. I tried to make something like AutoResponder but I guess it won't work out. I wanna know how can I make a seperated launcher for AutoResponder so when someone launches it, the website will be changed. I hope you understand what I'm trying to say. Thanks!

Hi,

I have nearly the same issue as in the topic "Can’t see the contents of HTTP Tunnel to port 443" discussed. But the difference is: while tunneling through fiddler, the app is not working properly. I inspected the packets with wireshark and when I am using fiddler, then the connection will be closed from client-side (fiddler) right after the "server hello" message. The last packet before the clientside FIN is the "change cipher spec, encrypted handshake message".

If I am not using fiddler as man in the middle, then everything works fine (hello, key exchange, change cipher spec, application data).

So it seems that fiddler closes the connection before all the data is exchanged. why?

With other connections (like google) fiddler works as expected, right after the connect message i can see the decrypted https traffic.

My setup is the following: I have MEmu (android emu) running on a windows machine and inside MEmu I configured my local machine on 8888 as proxy. This is working, if I google something from inside memu, everything is fine in fiddler. But if I use my app from inside memu, then the explained failure occures. 

Any help will be appreciated!

Thanks!