If you’re using a Self-Signed certificate for your HTTPS server, a deprecation coming to Chrome may affect your workflow. Chrome 58 will require [why?] that certificates specify the hostname(s) to which they apply in the SubjectAltName field; values in the Subject field will be ignored. This follows a similar change in Firefox 48. If impacted,Continue reading “Chrome Deprecates Subject CN Matching”
Tag Archives: Fiddler
Using Fiddler With iOS 10 and Android 7
If you’ve tried to use Fiddler with iOS10 beta or Android 7 Nougat, you have probably found that HTTPS decryption isn’t working, even if you use the latest Fiddler and the Fiddler Certificate Maker add-on. Unfortunately, at the moment both platforms are broken, but for different reasons. In both cases, the client will fail toContinue reading “Using Fiddler With iOS 10 and Android 7”
Silliness – Fiddler Blocks Malware
Enough malware researchers now depend upon Fiddler that some bad guys won’t even try to infect your system if you have Fiddler installed. The Malware Bytes blog post has the details, but the gist of it is that the attackers use JavaScript to probe the would-be victim’s PC for a variety of software. Beyond Kaspersky,Continue reading “Silliness – Fiddler Blocks Malware”
On Daylight Savings Time
In Fiddler, the Caching tab will attempt to calculate the cache freshness lifetime for responses that lack an explicit Expires or Cache-Control: max-age directive. The standard suggests clients use (0.1 * (DateTime.Now – Last-Modified)) as a heuristic freshness lifetime. An alert Fiddler user noticed that the values he was seeing were slightly off what he expected: sometimes the valuesContinue reading “On Daylight Savings Time”
Automatically Evaluating Compressibility
Fiddler’s Transformer tab has long been a simple way to examine the use of HTTP compression of web assets, especially as new compression engines (like Zopfli) and compression formats (like Brotli) arose. However, the one-Session-at-a-time design of the Transformer tab means it is cumbersome to use to evaluate the compressibility of an entire page orContinue reading “Automatically Evaluating Compressibility”
What’s New in Fiddler 4.6.2
TLDR? – Get the newest Fiddler here. It’s been just over two months since the last significant release, and Fiddler 4.6.2.0 (and v2.6.2.0) are now available. As always, the latest build includes a slew of bugfixes and minor tweaks, as well as a number of features described in this post. Default Certificate Generator Changed ChangesContinue reading “What’s New in Fiddler 4.6.2”
Segue
My last day at Telerik is December 31st, 2015. More soon… Here’s a copy of my “Last day” blog post for posterity. Fiddler—A Segue by Eric Lawrence December 22, 2015 Productivity, Debugging11 Comments In September 2012, Telerik completed the acquisition of the Fiddler Web Debugger, and I announced that I would join Telerik to upgrade my side project to my full-time job.Continue reading “Segue”
Book-Writing: Just Do It!
Sadly, you’re unlikely to get wealthy by writing a book. You should definitely write one anyway. My Background People I respect suggest you shouldn’t write (or buy) books on specific technologies, going so far as to say that writing a book was on their top-10 lists of life regrets. Top-10… whoa! As a consequence, whenContinue reading “Book-Writing: Just Do It!”
Repairing Corrupt ZIP Files
Fiddler’s default file format is the SAZ Format, which is just a ZIP file with a particular structure (I’ve written a lot about ZIPs). Unfortunately, sometimes users’ SAZ files get corrupted due to failing disks or incomplete downloads, and when this happens, Fiddler can no longer open them. Because Fiddler uses a standard ZIP file,Continue reading “Repairing Corrupt ZIP Files”
Reset Fiddler’s HTTPS certificates
I’ve made changes to the latest versions of Fiddler to improve the performance of certificate creation, and to avoid problems with new certificate validation logic coming to Chrome and Firefox. The biggest of the Fiddler changes is that CertEnroll is now the default certificate generator on Windows 7 and later. Unfortunately, this change can causeContinue reading “Reset Fiddler’s HTTPS certificates”
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