Find the new Fiddler blog here: http://blogs.telerik.com/fiddler/posts

-Eric

SmartAssembly Telemetry

Microsoft products use the Customer Experience Improvement Program (CEIP, sometimes called SQM) to collect telemetry from customer computers so we can better understand the configuration of those PCs and how the software is being used. Unfortunately, unlike Windows Error Reporting (sometimes called Watson) 3rd-party applications like Fiddler can’t participate in CEIP. Fortunately, as I announced in October, I discovered an alternative. Since then, the beta builds of Fiddler have been instrumented using RedGate’s SmartAssembly tool. SmartAssembly contains a bunch of useful features, including obfuscation, automated error reporting, and the one¹ Fiddler uses-- feature usage reporting.

I elected to instrument only the beta version to keep the amount of data collected to a reasonable size—while only a small fraction of the overall user-base, the beta audience is large enough to be statistically significant for the entire Fiddler population. There’s probably a bit of a bias because Beta users tend to be more “Advanced” than the average users, but I expect the effect is slight. I probably should change my strategy here to instead use a sampling percentage (e.g. 5% of users) but I haven’t found the need to do so thus far.

A total of 31,000 beta users have opted-in to data collection; data collected from the Version Check webservice (described shortly) suggests that this is about 20% of the users of the beta.

With just one call in Fiddler’s startup routine:

  SmartAssembly.ReportUsage.PlatformData.ReportAll();

…a set of basic information about the user’s environment is collected. The results were definitely interesting; more users than I had expected have .NET4 installed, while only a small percentage of users have multiple monitors. XP usage is still common, although Windows Vista and later account for 56 (and growing) percent of the machines running Fiddler.

Despite the fact that Fiddler itself is only available in English, a majority of Fiddler users run Fiddler on machines with a non-English locale (blue and purple are the US and Great Britain; all other colors are non-English):

This data should prove useful if I ever decide to translate Fiddler into other languages.

While the environment information is useful, the most interesting information comes from feature usage reporting. Basic information, including the count of sessions-per-user-per-day and the Fiddler version, is captured automatically. Adding application-specific metrics is simple. SmartAssembly offers two easy methods to instrument your code. First, you can add an attribute to any method and when that method is called, its counter will be incremented:

        #if TELEMETRY
          [SmartAssembly.ReportUsage.ReportUsage]
        #endif
        /// <summary>
        /// Show Fiddler's Options dialog
        /// </summary>
        [CodeDescription("Show the Fiddler Options dialog")]
        public void actShowOptions()

In some cases, you’ll want to capture events at a more granular level; in that case, just call the ReportUsage method with a string specifying the feature name:

        #if TELEMETRY
          SmartAssembly.ReportUsage.UsageCounter.ReportUsage("FiddlerBoot");
          if (CONFIG.bIsBeta) {
            SmartAssembly.ReportUsage.UsageCounter.ReportUsage("IsBeta");
          }   
        #endif

Feature usage reporting allows me to quickly see which features in Fiddler are most popular, as well as which features need to have their discoverability improved. For instance, I know which of Fiddler’s tabs are used in a session (AutoResponder tab is activated in 7 times as many sessions as the Composer), and which features are getting overlooked (Fiddler’s insanely powerful QuickExec feature gets used in only 1% of Sessions).

By pairing the SmartAssembly telemetry data with surveys and community feedback, a tiny team (i.e. me) can prioritize improvements to maximize the benefits for the tool's huge user-base.

Version Check Analysis

Of course, while rich telemetry is the most valuable, I’m also interested in getting some basic statistics from the entire userbase. By default, when Fiddler starts, it pings a web service to see whether a new version is available. As a part of this request, the current Windows version and Fiddler version are provided so that the web service can check for a compatible upgrade. I picked a random day, August 1st, and analyzed the data. It appears that only about 66% of users are using the latest version of Fiddler, released on June 23rd. Nearly a quarter of Fiddler users are using builds from the last two years, and about 4% of users are using truly ancient builds. 6% of the calls didn’t provide meaningful version information, either because the calls were fiddled (something that Fiddler is quite good at :-) or the builds were so old that the version information wasn’t present.

It’s a little sad to see that so many users aren’t getting the maximum benefit out of the many hundreds of hours of investment made in Fiddler over the past two years. (Not to mention the hundreds of bugfixes!) If you’re running an older version of Fiddler, please upgrade today.

Book Survey

In last fall's survey, just over a thousand Fiddler users indicated that they would buy a printed Fiddler book, and ~600 users indicated that they would purchase an E-Book on the topic. About 900 users said they’d read the EBook if it were free.

The Fiddler book was completed in June and is now available in paperback and DRM-less PDF format ($19 in paperback and $10 in PDF). The book turned out about 33% longer than I expected (it’s 330 pages) and has received good reviews. Sales have been brisk, and while I haven’t yet surpassed the goals suggested by the survey, I’m pretty happy with the results from the first two months. Additionally, two international publishers have tendered proposals for translated versions (Korean and Chinese) and a third (Japanese) is under consideration but not yet committed. Unfortunately, my plan to make the book available for free borrowing via the Kindle Lending Library hit two snags: first, the book doesn't work well on the non-Fire Kindles (because images and source code don't reformat well in .epub/.mobi), and second, Amazon's terms for books in the lending library prohibit making the book available from any other source in electronic form. That would preclude me offering the book to everyone who prefers the PDF format (which looks great on the iPad and PCs).

-Eric

¹ Fiddler doesn’t use the obfuscation feature because most of the classes are chock full of public methods, properties, and fields which must be callable from FiddlerScript and Extensions. Similarly, Fiddler already included a (manual) exception-reporting feature, so I elected not to switch over to the SmartAssembly version.

You can learn more about the book at http://fiddlerbook.com. The site includes a link to the final Table-of-Contents, as well as all of the code samples in the book.

Thanks for your interest in Fiddler!

-Eric

Acknowledgements............................................................................................................................................................ iii

Table of Contents................................................................................................................................................................ iv

Origins.................................................................................................................................................................................... 1

About this book............................................................................................................................................................... 3

A Quick Primer..................................................................................................................................................................... 5

Basic Concepts................................................................................................................................................................. 5

Fiddler Scenarios............................................................................................................................................................ 6

Getting Started with Fiddler............................................................................................................................................... 8

System Requirements.................................................................................................................................................... 8

Installing Fiddler.............................................................................................................................................................. 8

Updating Fiddler.............................................................................................................................................................. 9

The Fiddler User-Interface............................................................................................................................................... 10

The Web Sessions List.................................................................................................................................................. 10

Web Sessions Context Menu...................................................................................................................................... 13

Fiddler’s Main Menu......................................................................................................................................................... 17

Fiddler’s About Box...................................................................................................................................................... 22

Fiddler’s Toolbar................................................................................................................................................................ 24

Fiddler’s Status Bar....................................................................................................................................................... 25

Application Hotkeys.......................................................................................................................................................... 26

QuickExec........................................................................................................................................................................... 27

The Fiddler User-Interface............................................................................................................................................... 32

Comparing Sessions........................................................................................................................................................... 33

Debugging with Breakpoints............................................................................................................................................ 35

Statistics Tab....................................................................................................................................................................... 38

The Filters tab..................................................................................................................................................................... 40

Request Headers.......................................................................................................................................................... 41

The Timeline tab................................................................................................................................................................ 45

Mode: Timeline............................................................................................................................................................. 45

Mode: Client Pipe Map................................................................................................................................................ 47

Mode: Server Pipe Map.............................................................................................................................................. 47

The AutoResponder tab................................................................................................................................................... 48

Specifying the Match Condition................................................................................................................................. 49

Specifying the Action Text.......................................................................................................................................... 50

Using RegEx Replacements in Action Text................................................................................................................ 51

Drag-and-Drop support............................................................................................................................................... 52

FARX Files....................................................................................................................................................................... 53

Encoding and Decoding Text with the TextWizard...................................................................................................... 54

A Few Words on Character Encodings...................................................................................................................... 55

The Composer tab............................................................................................................................................................. 56

The Log tab......................................................................................................................................................................... 60

The Find Sessions Dialog................................................................................................................................................... 61

The HOSTS Dialog............................................................................................................................................................... 63

Retargeting Traffic with Fiddler....................................................................................................................................... 64

Features to Retarget Requests................................................................................................................................... 66

Sending Traffic to Fiddler................................................................................................................................................. 67

Capturing Traffic from Browsers................................................................................................................................ 67

Capturing Traffic from Other Applications............................................................................................................... 69

Capturing Traffic from Services.................................................................................................................................. 70

Capturing Traffic to Loopback.................................................................................................................................... 70

Running Fiddler on Mac OSX...................................................................................................................................... 73

Capturing Traffic from Other Computers................................................................................................................. 74

Capturing Traffic from Devices................................................................................................................................... 75

Using Fiddler as a Reverse Proxy............................................................................................................................... 76

Chaining to Upstream Proxy Servers......................................................................................................................... 77

Chaining to SOCKS / TOR............................................................................................................................................. 77

VPNs, Modems, and Tethering................................................................................................................................... 78

DirectAccess.................................................................................................................................................................. 78

Buffering vs. Streaming Traffic........................................................................................................................................ 79

Request Buffering......................................................................................................................................................... 79

Response Buffering...................................................................................................................................................... 79

COMET............................................................................................................................................................................ 79

HTML5 WebSockets.......................................................................................................................................................... 81

Fiddler and HTTPS.............................................................................................................................................................. 82

Configuring Clients for HTTPS Decryption..................................................................................................................... 85

Certificate Validation......................................................................................................................................................... 86

Apple iOS and Android..................................................................................................................................................... 87

Client Certificates.............................................................................................................................................................. 88

Client Certificates.............................................................................................................................................................. 89

Fiddler and FTP.................................................................................................................................................................. 90

Memory Use and Fiddler’s Bitness................................................................................................................................. 91

Fiddler and Web Authentication.................................................................................................................................... 93

HTTP Authentication.................................................................................................................................................... 93

Automatic Authentication in Fiddler......................................................................................................................... 94

Authentication Issues................................................................................................................................................... 95

HTTPS Client Certificates............................................................................................................................................. 96

Inspectors........................................................................................................................................................................... 98

Auth (Request / Response)............................................................................................................................................ 100

Caching (Response; ReadOnly)..................................................................................................................................... 102

Cookies (Request / Response; ReadOnly)................................................................................................................... 103

Headers (Request/Response; Read/Write)................................................................................................................ 104

Context Menu............................................................................................................................................................. 105

Keyboard Shortcuts................................................................................................................................................... 105

Editing........................................................................................................................................................................... 105

HexView (Request / Response; Read/Write)............................................................................................................. 107

ImageView (Response; ReadOnly)................................................................................................................................ 109

JSON (Request / Response; ReadOnly)........................................................................................................................ 110

Raw (Request / Response; Read/Write)...................................................................................................................... 111

SyntaxView (Request / Response; Read/Write)......................................................................................................... 112

TextView (Request / Response; Read/Write)............................................................................................................. 114

Transformer (Response; Read/Write)......................................................................................................................... 115

WebForms (Request; Read/Write).............................................................................................................................. 117

WebView (Response; ReadOnly).................................................................................................................................. 118

XML (Request / Response; ReadOnly)......................................................................................................................... 119

Fiddler Options................................................................................................................................................................ 120

General Options......................................................................................................................................................... 120

HTTPS Options............................................................................................................................................................. 121

Extensions Options..................................................................................................................................................... 122

Connections Options................................................................................................................................................. 123

Appearance Options.................................................................................................................................................. 124

Preferences..................................................................................................................................................................... 125

Understanding Text Encodings...................................................................................................................................... 126

Fiddler Extensions........................................................................................................................................................... 127

Gallery............................................................................................................................................................................... 128

Full-Screen View......................................................................................................................................................... 128

Content Blocker............................................................................................................................................................... 130

FiddlerScript Editors....................................................................................................................................................... 132

FiddlerScript Tab........................................................................................................................................................ 132

ClassView Sidebar....................................................................................................................................................... 133

Fiddler2 ScriptEditor.................................................................................................................................................. 133

SAZ Clipboard................................................................................................................................................................... 135

Traffic Differ..................................................................................................................................................................... 136

AnyWHERE........................................................................................................................................................................ 137

JavaScript Formatter....................................................................................................................................................... 138

Session Archive Zip (SAZ) Files...................................................................................................................................... 139

Protecting SAZ Files................................................................................................................................................... 139

Importing and Exporting Sessions................................................................................................................................. 141

Import Formats........................................................................................................................................................... 141

Export Formats............................................................................................................................................................ 141

Fiddler’s Viewer Mode................................................................................................................................................... 146

FiddlerCap........................................................................................................................................................................ 147

Capture Box................................................................................................................................................................. 147

Capture Options Box.................................................................................................................................................. 148

Tools Box...................................................................................................................................................................... 149

Using Fiddler for Performance Debugging................................................................................................................. 152

Using Fiddler for Content Collection............................................................................................................................ 153

Using Fiddler for Security Analysis............................................................................................................................... 154

Configuration for IT Administrators.............................................................................................................................. 155

Using Fiddler for Compatibility Diagnosis.................................................................................................................... 156

Extending Fiddler with FiddlerScript............................................................................................................................ 158

About FiddlerScript.................................................................................................................................................... 158

Editing FiddlerScript................................................................................................................................................... 159

FiddlerScript Functions.................................................................................................................................................. 161

Session Handling Functions...................................................................................................................................... 161

General Functions...................................................................................................................................................... 162

Automating Fiddler......................................................................................................................................................... 164

Extending Fiddler’s UI - Menus..................................................................................................................................... 167

Extending the Tools Menu........................................................................................................................................ 167

Extending the Web Sessions Context Menu.......................................................................................................... 168

Extending the Rules Menu........................................................................................................................................ 168

Creating New Top-Level Menus............................................................................................................................... 171

Extending Fiddler’s UI - Adding Columns to the Web Sessions List........................................................................ 173

Binding Columns using Attributes............................................................................................................................ 173

Binding Columns using AddBoundColumn............................................................................................................. 175

FiddlerObject Functions................................................................................................................................................. 177

Referencing Assemblies................................................................................................................................................. 180

Interacting with Fiddler.................................................................................................................................................. 181

Sample Scripts.................................................................................................................................................................. 182

Extending Fiddler with .NET........................................................................................................................................... 186

Project Requirements and Settings......................................................................................................................... 187

Debugging Extensions................................................................................................................................................ 187

Best Practices for Extensions................................................................................................................................... 187

Interacting with Fiddler.................................................................................................................................................. 192

Understanding SessionStates................................................................................................................................... 192

SessionFlags................................................................................................................................................................. 192

Sending Strings to the TextWizard.......................................................................................................................... 193

Logging Events............................................................................................................................................................ 194

Interacting with the FiddlerScript Engine............................................................................................................... 194

Programming with Preferences.................................................................................................................................... 196

Preference Naming.................................................................................................................................................... 196

The IFiddlerPreferences Interface.......................................................................................................................... 196

Storing and Removing Preferences........................................................................................................................ 197

Retrieving Preferences............................................................................................................................................. 197

Watching for Preference Changes.......................................................................................................................... 197

Notifications in Extensions........................................................................................................................................ 197

Notifications in FiddlerScript.................................................................................................................................... 198

Building Extension Installers.......................................................................................................................................... 199

Building Inspectors.......................................................................................................................................................... 202

Inspecting the Session Object.................................................................................................................................. 205

Dealing with HTTP Compression and Chunking.......................................................................................................... 208

Decoding a Copy of the Body................................................................................................................................... 208

Using the GetRe*BodyAsString Methods............................................................................................................... 209

Using the utilDecode* Methods.............................................................................................................................. 209

Inspector Assemblies................................................................................................................................................. 210

Fiddler Extensions........................................................................................................................................................... 211

Integrating with QuickExec....................................................................................................................................... 212

Extension Assemblies................................................................................................................................................ 213

Import and Export Transcoders.................................................................................................................................... 214

Handling Options........................................................................................................................................................ 216

Going Beyond Files..................................................................................................................................................... 218

FiddlerCore...................................................................................................................................................................... 224

Legalities...................................................................................................................................................................... 225

Getting Started with FiddlerCore............................................................................................................................. 225

Compiling the Sample Application........................................................................................................................... 225

The FiddlerCoreStartupFlags.................................................................................................................................... 227

The FiddlerApplication Class......................................................................................................................................... 229

FiddlerApplication Events......................................................................................................................................... 229

FiddlerApplication Methods..................................................................................................................................... 230

FiddlerApplication Properties and Fields............................................................................................................... 231

Fiddler API................................................................................................................................................................... 231

Common Tasks with FiddlerCore.................................................................................................................................. 233

Other resources......................................................................................................................................................... 234

Appendix A: Troubleshooting....................................................................................................................................... 236

Missing Traffic............................................................................................................................................................. 236

Interference from Security Software..................................................................................................................... 237

Corrupted Proxy Settings.......................................................................................................................................... 238

Resetting Fiddler........................................................................................................................................................ 238

Troubleshooting Certificate Problems.................................................................................................................... 239

Wiping all traces of Fiddler....................................................................................................................................... 240

Fiddler crashes complaining about the "Configuration System"........................................................................ 240

Fiddler randomly stops capturing traffic................................................................................................................ 240

Fiddler stalls streaming RPC-over-HTTPS traffic.................................................................................................... 241

Appendix B: Command Line Syntax............................................................................................................................. 242

Option Flags................................................................................................................................................................. 242

Appendix C: Session Flags.............................................................................................................................................. 243

Session Display Flags.................................................................................................................................................. 243

Breakpoint and Editing Flags..................................................................................................................................... 244

Network Routing Flags............................................................................................................................................... 245

Performance Simulation Flags.................................................................................................................................. 247

Client Information Flags............................................................................................................................................. 247

HTTPS Flags.................................................................................................................................................................. 248

Appendix D: Preferences.............................................................................................................................................. 254

Network Preferences................................................................................................................................................ 254

HTTPS Preferences.................................................................................................................................................... 257

Fiddler UI Preferences.............................................................................................................................................. 259

Path Configuration..................................................................................................................................................... 265

Miscellaneous............................................................................................................................................................. 266

Extension Preferences.............................................................................................................................................. 266

Index.................................................................................................................................................................................. 270

So, what’s going on?

When I need to troubleshoot issues that occur below Fiddler, NetMon is a good choice. Taking a look at the HTTPS handshake, the problem is immediately apparent:

This server is returning a TLS Alert at the beginning of the handshake. The alert severity is 1 meaning WARNING, and the code is 112 (0x70) which is the unrecognized_name alert. With this alert, the server is indicating that it does not recognize the hostname provided by the server’s Server Name Indication TLS extension. This warning is only encountered when the client is running on Windows Vista and later because the SChannel HTTPS stack on Windows XP doesn’t support SNI and other TLS extensions.

The server’s behavior is explicitly not recommended according to the standards:

If the server understood the ClientHello extension but does not recognize the server name, the server SHOULD take one of two actions: either abort the handshake by sending a fatal-level unrecognized_name(112) alert or continue the handshake. It is NOT RECOMMENDED to send a warning-level unrecognized_name(112) alert, because the client's behavior in response to warning-level alerts is unpredictable. If there is a mismatch between the server name used by the client application and the server name of the credential chosen by the server, this mismatch will become apparent when the client application performs the server endpoint identification, at which point the client application will have to decide whether to proceed with the communication.

The server’s behavior is problematic because the .NET Framework’s HTTPS implementation is unable to ignore this warning and it is not able to automatically “fail over” to an earlier protocol version, leading to a  lengthy delay (~80 seconds) before a connection failure in Fiddler or other .NET applications.

To enable Fiddler to workaround sites with this problematic configuration, click Rules > Customize Rules. Scroll to the OnBeforeRequest method and add the following block:

if (oSession.HTTPMethodIs("CONNECT") && oSession.HostnameIs("BuggySite.com"))
{
  oSession["x-OverrideSslProtocols"] = "ssl3";
  FiddlerApplication.Log.LogString("Legacy compat applied for inbound request to BuggySite.com");
}

Save the script and this block will force Fiddler to handshake with the server using only the SSLv3 protocol, which does not send TLS extensions, avoiding the problem.

To apply the same workaround in your .NET application without Fiddler, use the same trick: ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3;

-Eric

Install the new Privacy Scanner add-on and Fiddler will gain a new top-level menu named Privacy.

The menu has two options. The Enabled option controls whether the add-on does anything at all; it’s a good practice for Add-ons to offer a simple way to turn them off when they’re not wanted.

When the add-on is enabled, it will add a Privacy Info column to the session list and will flag HTTP/HTTPS responses which set cookies. Evaluation of any P3P statements that come along with those cookies will change the session's background color:

Sessions that send a satisfactory P3P policy are shown in green. Sessions that set a cookie without a P3P policy are yellow; in the default IE settings, these cookies will not be sent to a 3rd party context. Sessions that send a P3P policy that does not permit use of the cookie in a 3rd party context are rendered in orange. Sessions that send invalid P3P header tokens will have a red background.

When the menu option Rename P3P header if invalid is checked, if a session presents a P3P statement that is malformed, that P3P header will be renamed to Malformed-P3P to prevent the browser from interpreting it as the P3P 1.0 specification suggested (e.g. ignoring the unknown tokens). You can see the difference when you load this test page; the cookies with bogus compact policies will be dropped in a 3rd party context.

For folks looking to build their own Fiddler extension, the code is provided below.

-Eric

using System;

using System.Collections;

using System.Globalization;

using System.Collections.Generic;

using System.Windows.Forms;

using System.Text;

using Fiddler;

using System.IO;

using System.Diagnostics;

using Microsoft.Win32;

using System.Reflection;

using System.Text.RegularExpressions;

[assembly: Fiddler.RequiredVersion("2.3.9.0")]

[assembly: AssemblyVersion("1.0.1.0")]

[assembly: AssemblyTitle("PrivacyScanner")]

[assembly: AssemblyDescription("Scans for Cookies and P3P")]

[assembly: AssemblyCompany("Eric Lawrence")]

[assembly: AssemblyProduct("PrivacyScanner")]

public class TagCookies : IAutoTamper2

{

    private bool bEnabled = false;

    private bool bEnforceP3PValidity = false;

    private bool bCreatedColumn = false;

    private System.Windows.Forms.MenuItem miEnabled;

    private System.Windows.Forms.MenuItem miEnforceP3PValidity;

    private System.Windows.Forms.MenuItem mnuCookieTag;

    public void OnLoad()

    {

        /*

 * NB: You might not get called here until ~after~ one of the AutoTamper methods was called.

 * This is okay for us, because we created our mnuContentBlock in the constructor and its simply not

 * visible anywhere until this method is called and we merge it onto the Fiddler Main menu.

 */

        FiddlerApplication.UI.mnuMain.MenuItems.Add(mnuCookieTag);

    }

    public void OnBeforeUnload() {  /*noop*/   }

    private void InitializeMenu()

    {

        this.miEnabled = new System.Windows.Forms.MenuItem("&Enabled");

        this.miEnforceP3PValidity = new System.Windows.Forms.MenuItem("&Rename P3P header if invalid");

        this.miEnabled.Index = 0;

        this.miEnforceP3PValidity.Index = 1;

        this.mnuCookieTag = new System.Windows.Forms.MenuItem();

        this.mnuCookieTag.MenuItems.AddRange(new System.Windows.Forms.MenuItem[] { this.miEnabled, this.miEnforceP3PValidity });

        this.mnuCookieTag.Text = "Privacy";

        this.miEnabled.Click += new System.EventHandler(this.miEnabled_Click);

        this.miEnabled.Checked = bEnabled;

        this.miEnforceP3PValidity.Click += new System.EventHandler(this.miEnforceP3PValidity_Click);

        this.miEnforceP3PValidity.Checked = bEnforceP3PValidity;

    }

    public void miEnabled_Click(object sender, EventArgs e)

    {

        miEnabled.Checked = !miEnabled.Checked;

        bEnabled = miEnabled.Checked;

        this.miEnforceP3PValidity.Enabled = bEnabled;

        if (bEnabled) { EnsureColumn(); }

        FiddlerApplication.Prefs.SetBoolPref("extensions.tagcookies.enabled", bEnabled);

    }

    public void miEnforceP3PValidity_Click(object sender, EventArgs e)

    {

        miEnforceP3PValidity.Checked = !miEnforceP3PValidity.Checked;

        bEnforceP3PValidity = miEnforceP3PValidity.Checked;

        FiddlerApplication.Prefs.SetBoolPref("extensions.tagcookies.EnforceP3PValidity", bEnforceP3PValidity);

    }

    private void EnsureColumn()

    {

        if (bCreatedColumn) return;

        FiddlerApplication.UI.lvSessions.AddBoundColumn("Privacy Info", 1, 120, "X-Privacy");

        bCreatedColumn = true;

    }

    public TagCookies()

    {

        this.bEnabled = FiddlerApplication.Prefs.GetBoolPref("extensions.tagcookies.enabled", false);

        this.bEnforceP3PValidity = FiddlerApplication.Prefs.GetBoolPref("extensions.tagcookies.EnforceP3PValidity", true);

        InitializeMenu();

        if (bEnabled) { EnsureColumn(); } else { this.miEnforceP3PValidity.Enabled = false; }

    }

    private void SetP3PStateFromHeader(string sValue, ref P3PState oP3PState)

    {

        if (string.IsNullOrEmpty(sValue))

        {

            return;

        }

        string sUnsatCat = String.Empty;

        string sUnsatPurpose = String.Empty;

        sValue = sValue.Replace('\'', '"');

        string sCP = null;

        Regex r = new Regex("CP\\s?=\\s?[\"]?(?<TokenValue>[^\";]*)");

        Match m = r.Match(sValue);

        if (m.Success && (null != m.Groups["TokenValue"]))

        {

            sCP = m.Groups["TokenValue"].Value;

        }

        if (String.IsNullOrEmpty(sCP))

        {

            return;

        }

        // Okay, we've got a compact policy token.

        oP3PState = P3PState.P3POk;

        string[] sTokens = sCP.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);

        foreach (string sToken in sTokens)

        {

            // Reject clearly invalid tokens...

            if ((sToken.Length < 3) || (sToken.Length > 4))

            {

                oP3PState = P3PState.P3PMalformed;

                return;

            }

            if (",PHY,ONL,GOV,FIN,".IndexOf("," + sToken + ",", StringComparison.OrdinalIgnoreCase) > -1)

            {

                sUnsatCat += (sToken + " ");

                continue;

            }

            if (",SAM,OTR,UNR,PUB,IVA,IVD,CON,TEL,OTP,".IndexOf("," + sToken + ",", StringComparison.OrdinalIgnoreCase) > -1)

            {

                sUnsatPurpose += (sToken + " ");

                continue;

            }

            // TODO: Look up the token in the complete collection and check validity

        }

        // If a cookie contains an unsatisfactory purpose and an unsatisfactory category, mark it

        // http://msdn.microsoft.com/en-us/library/ie/ms537343(v=vs.85).aspx#unsatisfactory_cookies

        if ((sUnsatCat.Length > 0) && (sUnsatPurpose.Length > 0))

        {

            if (oP3PState == P3PState.P3POk)

            {

                oP3PState = P3PState.P3PUnsatisfactory;

            }

        }

    }

    private enum P3PState

    {

        NoCookies,

        NoP3PAndSetsCookies,

        P3POk,

        P3PUnsatisfactory,

        P3PMalformed

    }

    public void OnPeekAtResponseHeaders(Session oSession) 

    {

        if (!bEnabled) return;

        P3PState oP3PState = P3PState.NoCookies;

        if (!oSession.oResponse.headers.Exists("Set-Cookie"))

        {

            return;

        }

        oP3PState = P3PState.NoP3PAndSetsCookies;

        if (oSession.oResponse.headers.Exists("P3P"))

        {

            SetP3PStateFromHeader(oSession.oResponse.headers["P3P"], ref oP3PState);

        }

        switch (oP3PState)

        {

            case P3PState.P3POk:

                oSession["ui-backcolor"] = "#ACDC85";

                oSession["X-Privacy"] = "Sets cookies & P3P";

                break;

            case P3PState.NoP3PAndSetsCookies:

                oSession["ui-backcolor"] = "#FAFDA4";

                oSession["X-Privacy"] = "Sets cookies without P3P";

                break;

            case P3PState.P3PUnsatisfactory:

                oSession["ui-backcolor"] = "#EC921A";

                oSession["X-Privacy"] = "Sets cookies; P3P unsatisfactory for 3rd-party use";

                break;

            case P3PState.P3PMalformed:

                oSession["ui-backcolor"] = "#E90A05";

                if (bEnforceP3PValidity)

                {

                    oSession.oResponse.headers["MALFORMED-P3P"] = oSession.oResponse.headers["P3P"];

                    oSession["X-Privacy"] = "MALFORMED P3P: " + oSession.oResponse.headers["P3P"];

                    oSession.oResponse.headers.Remove("P3P");

                }

                break;

        }

    }

    public void AutoTamperRequestBefore(Session oSession) { }

    public void AutoTamperRequestAfter(Session oSession){ /*noop*/ }

    public void AutoTamperResponseAfter(Session oSession) {/*noop*/}

    public void AutoTamperResponseBefore(Session oSession) { /*noop*/ }

    public void OnBeforeReturningError(Session oSession) {/*noop*/}

}

and use the new Edit > Paste Files as Sessions command:

… to instruct Fiddler to parse the DataURI and create a new Session for it. You can then use Fiddler’s inspectors to examine the resulting object:

Next, the WebView Inspector has been enhanced to render previews of WOFF font, MP3 audio, and H264 video responses, if you have IE9+ installed:

Lastly, Fiddler’s AutoResponder now permits you to use Regular Expression Group Replacements to map one URL to another. For instance, this rule:

…will convert http://somesite.com/assets/Test1.gif to http://www.example.com/mockup/Test1.gif. This capability makes it even easier to replace content using Fiddler’s AutoResponder.

This new build of Fiddler has a ton of other fixes and performance improvements. I hope you enjoy it!

-Eric

Over on his blog, Mark Rideout explains the root cause of Lenovo’s scrolling problem and explains how .NET developers can workaround the bug by adding hidden scrollbar controls to trick the driver software. I’ll be looking at using this trick in a future version of Fiddler. For now, a cumbersome but effective configuration tweak to the Lenovo driver settings allows end-users to get scrolling working properly in Fiddler and most other applications.

Start Notepad using the Run As Administrator option. Open the file C:\program files\lenovo\trackpoint\tp4table.dat (note that the tp4table.dat file may be in another path on your computer). Add the lines in blue under the existing lines in grey.

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; Pass 1 rules (These rules run last)
;
; If no scrolling method was found with the builtin logic, then
; these rules are checked.
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; Fiddler
*,*,Fiddler.exe,*,*,*,WheelStd,1,9

Restart your system to force the driver software to reload its settings, and you should find that middle-click-scrolling works properly in Fiddler.

Until next time…

-Eric