Questions on Fiddler Forum

1 answer

847 views

FiddlerScript customization throws and error in Scriptbase.cs:919

Hi, I'm trying to proxy and cache some responses that are being redownloaded over and over.

To do that I wrote this simple customization in FiddlerScript:

static function OnBeforeResponse(oSession: Session) {

var captureRequests = false;

var targetHost = "api.nuget.org";

var captureFolder = "c:\\Projects\\Fiddler\\api.nuget.org";

// Capture traffic

if (captureRequests && oSession.host.toLowerCase() == targetHost)

{

var targetFile = captureFolder + oSession.PathAndQuery.Split('?')[0].Replace('/','\\');

oSession.oResponse["X-oSession-PathAndQuery"] = targetFile;

var fi = new FileInfo(targetFile);

Directory.CreateDirectory(fi.DirectoryName)

if(!File.Exists(fi.FullName))

{

File.WriteAllBytes(fi.FullName, oSession.ResponseBody);

}

// // Replay captured

var replayRequests = true;

if (replayRequests&& oSession.host.toLowerCase() == targetHost)

{

var targetFile = captureFolder +"\\" + oSession.PathAndQuery.Split('?')[0].Replace('/','\\');

var fi = new FileInfo(targetFile);

if(!File.Exists(fi.FullName))

{

oSession["x-replywithfile"] = fi.FullName;

}

And presumably it should work - when captureRequests=true - fiddler captures requests from a particular domain into a folder, preserving path and file name

When replayRequests = true - it simply replays existing files.

The problem here that even if I just capturing the data (I suspect I may be replaying too late - fiddler would call http already by that time...) - fiddler throws a lot of errors with this text:

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

FiddlerScript OnBeforeResponse() failed.

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

There was a problem with your FiddlerScript.

The given path's format is not supported.

at System.Security.Permissions.FileIOPermission.EmulateFileIOPermissionChecks(String fullPath)

at System.Security.Permissions.FileIOPermission.QuickDemand(FileIOPermissionAccess access, String fullPath, Boolean checkForDuplicates, Boolean needFullPath)

at System.IO.FileInfo.Init(String fileName, Boolean checkHost)

at Fiddler.ScriptNamespace.Handlers.OnBeforeResponse(Session oSession)

at Fiddler.ScriptBase.(Session ) in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Application\Scripting\ScriptBase.cs:line 919

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

OK

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

I tried to investigate it by playing with code and identified that for some reason a typical file path like `c:\Projects\Fiddler\api.nuget.org\v3\registration1-gz\analytics\index.json` causes an error. Or that code is somehow not thread safe and competing requests simply break it (and visual studio starts them in parallel so there is a high chance of some kind of race).

Can anyone suggest what am I doing wrong here or maybe advice on better solution to the problem.

Extensions and Customization

answered on 04 May 2017

0 answers

385 views

cannot see headers

Hello,

I hope this is the correct forum for my question.

I am learning to use Fiddler (for debugging API's issues) hence I could be asking a question which is very basic or non-sensical, in this case I apologise upfront.

I would like Fiddler to show the streams going to Shopify using their API's:- in this example I have a simple GET Customers coded in Microsoft Dotnet. The API works 100% and it returns the expected XML list of current Shopify Customers.

However, when I look at the Fiddler data, it does NOT show the Authentication Headers:- I was expecting to see my Shopify API Key and Password.

Would anyone be able to explain why Fiddler states there isno Authorization Header where I used it in the API call?

Thanks

Fiddler Classic

asked on 04 May 2017

0 answers

143 views

Radio button prompting in rules

Is there a way to do a radio button effect that I can leverage in the custom rules.

I want to prompt for which one of a small set of choices should be used as the Session[i].hostname to run the selected tests.

Select host:

- localhost

- xxx.yyy.com

-aaa.bbb.com

Or if there is a better more in-built way to dynamically change the hostname for all selected sessions per run.

Extensions and Customization

asked on 03 May 2017

0 answers

282 views

HTTPS Handshake failure: AuthenticationException

I am receiving an error from Fiddler when attempting to decrypt HTTPS traffic from a specific site. Other HTTPS sites seem to be working Ok.

The error is "fiddler.network.https> HTTPS handshake to login.nbnco.net.au"

URL : https://login.nbnco.net.au/portal-login

Fiddler Version :

v4.6.20171.14978
Built: Tuesday, 21 March 2017
64-bit AMD64, VM: 110.0mb, WS: 90.0mb
.NET 4.6.2 WinNT 6.1.7601 SP1

HTTPS protocols being used : <client>;ssl3;tls1.0

Browsers used :

Chrome Latest - Version 58.0.3029.96 (64-bit)

Internet Explorer : Version 11.0.9600.18638

Fiddler Log :

11:46:38:4535 fiddler.network.https> HTTPS handshake to login.nbnco.net.au (for #1136) failed. System.Security.Authentication.AuthenticationException A call to SSPI failed, see inner exception. < The message received was unexpected or badly formatted

Win32 (SChannel) Native Error Code: 0x80090326

Can anyone tell me what is happening here? And any steps I can take to rectify?

I have already followed other advice I have seen regarding Resetting Certificates, and restarting Fiddler.

Much thanks!!!

Chris

Windows

asked on 03 May 2017

1 answer

4.3K+ views

Fiddler introduces 504 Gateway Timeout

When connecting direct with a particular website/request, everything runs happily, but as soon as Fiddler is introduced into the equation, a 504 Gateway Timeout occurs.

The request in question is an http request on port 443.

Is it an issue that can be fixed?

Fiddler Classic

answered on 02 May 2017

0 answers

243 views

fiddler crash

---------------------------
Uncaught Exception in Session #1
---------------------------
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.

Object reference not set to an instance of an object.

Type: System.NullReferenceException
Source: KennySpeeder
at SpeedLimit.AutoTamperRequestBefore(Session oSession)

at Fiddler.FiddlerExtensions.(Session ) in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Application\Extensions.cs:line 798

at Fiddler.Session.() in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\Session.cs:line 5195

at Fiddler.Session.() in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\Session.cs:line 3394

at Fiddler.Session.(Object ) in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\Session.cs:line 3347

Fiddler v4.6.20171.14978 (x64 AMD64) [.NET 4.0.30319.18052 on Microsoft Windows NT 6.1.7601 Service Pack 1]
---------------------------
确定
---------------------------

FiddlerCore

asked on 02 May 2017

2 answers

110 views

mozroots in subdirectory

The instructions on http://www.telerik.com/blogs/fiddler-for-linux-beta-is-here for installing Fiddler for Linux Beta mention running /usr/lib/mono//mozroots --import --sync. However I don't have that application. Instead, mozroot is to be found in /usr/lib/mono/4.5. The documentation might confuse some folk.

For info, Linux Mint 18.1. Mono installed through apt install mono-complete.

Just a quick aside, why does the forum sign-up insist on the user entering a company name? We don't all work for companies.

Linux

answered on 02 May 2017

0 answers

265 views

ArgumentExcetion on Shift+R

Hi.

I get the following exception when I want to repeat a request via Shift + R

Once I press OK, the process continues with Repeat Count prompt and the repetition works.

Thanks

---------------------------
Awww, Fiddlesticks!
---------------------------
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.

Value of 'null' is not valid for 'stream'.

Type: System.ArgumentException
Source: System.Drawing
at System.Drawing.Image.FromStream(Stream stream, Boolean useEmbeddedColorManagement, Boolean validateImageData)

at Fiddler.frmPrompt.GetUserString(IWin32Window wndOwner, String sTitle, String sPrompt, String sDefault, Boolean bReturnNullIfCancelled, PromptIcon piIcon) in c:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\frmPrompt.cs:line 84

Fiddler v4.6.3.50306 (x64 AMD64) [.NET 4.0.30319.42000 on Microsoft Windows NT 6.1.7601 Service Pack 1]
---------------------------
OK
---------------------------

Windows

asked on 01 May 2017

2 answers

1.3K+ views

AutoResponder, two URLs and two different request methods

I have the following scenario: There are a OPTIONS and a GET request for the same URL. I want to use the AutoResponder to only modify the GET request. How can that be accomplished in terms of setting up the correct rule?

Fiddler Classic

answered on 26 Apr 2017

2 answers

590 views

Session import for packet capture

Hello,

I have a packet capture which throws error while importing to Fiddler. I have selected one packet from capture and uploaded the capture to https://www.sendspace[.]com/file/rqnqs9 to find our what is different about this capture from the other usual captures that I am able to import without any problems. I have also attached the error screenshot that I get while I import this capture. Please feel free to delete this thread if this is not appropriate to be asked here.

Regards,

Rohit

Windows

answered on 25 Apr 2017