Certificate Revocation in Microsoft Edge

When you visit a HTTPS site, the server must present a certificate, signed by a trusted third-party (a Certificate Authority, aka CA), vouching for the identity of the bearer. The certificate contains an expiration date, and is considered valid until that date arrives. But what if the CA later realizes that it issued the certificateContinue reading “Certificate Revocation in Microsoft Edge”

Extending Fiddler’s ImageView

Fiddler’s ImageView Inspector offers a lot of powerful functionality for inspecting images and discovering ways to shrink an image’s byte-weight without impacting its quality. Less well-known is the fact that the ImageView Inspector is very extensible, such that you can add new tools to it very simply. To do so, simply download any required executablesContinue reading “Extending Fiddler’s ImageView”

“Batteries-Included” vs “Bloated”

Fundamentals are invisible. Features are controversial. One of the few common complaints against Microsoft Edge is that “It’s bloated– there’s too much stuff in it!” A big philosophical question for designers of popular software concerns whether the product should include features that might not be useful for everyone or even a majority of users. ThereContinue reading ““Batteries-Included” vs “Bloated””

Chromium Internals: PAK Files

Web browsers are made up of much more than the native code (mostly compiled C++) that makes up their .exe and .dll files. A significant portion of the browser’s functionality (and bulk) is what we’d call “resources”, which include things like: Images (at two resolutions, regular and “high-DPI”) Localized UI Strings HTML, JavaScript, and CSSContinue reading “Chromium Internals: PAK Files”

Chromium’s DNS Cache

From the mailbag: Q: How long does Chromium cache hostnames? I know a user can clear the hostname cache using the Clear host cache button on about://net-internals/#dns, but how long it will take for the cache to be removed if no manual action is taken? After changing DNS records on my server, nslookup from aContinue reading “Chromium’s DNS Cache”

Leaky Abstractions

In the late 1990s, the Windows Shell and Internet Explorer teams introduced a bunch of brilliant and intricate designs that allowed extension of the shell and the browser to handle scenarios beyond what those built by Microsoft itself. For instance, Internet Explorer supported the notion of pluggable protocols (“What if some protocol, say, FTPS, becomesContinue reading “Leaky Abstractions”

Web Proxy Auto Discovery (WPAD)

Back in the mid-aughts, Adam G., a colleague on the IE team, used the email signature “IE Networking Team – Without us, you’d be browsing your hard drive.” And while I’m sure it was meant to be a bit tongue-in-cheek, it’s really true– without a working network stack, web browsers aren’t nearly as useful. BackgroundContinue reading “Web Proxy Auto Discovery (WPAD)”

The Pitfalls of EventSource over HTTP/1.1

While there are many different ways for servers to stream data to clients, the Server-sent Events / EventSource Interface is one of the simplest. Your code simply creates an EventSource and then subscribes to its onmessage callback: Implementing the server side is almost as simple: your handler just prefaces each piece of data it wantsContinue reading “The Pitfalls of EventSource over HTTP/1.1”

Private Browsing Mode

Note: This blog post was written before the new Chromium-based Microsoft Edge was announced. As a consequence, it mostly discusses the behavior of the Legacy Microsoft Edge browser. The new Chromium-based Edge behaves largely the same way as Google Chrome. InPrivate Mode was introduced in Internet Explorer 8 with the goal of helping users improveContinue reading “Private Browsing Mode”

Finding Image Bloat In Binary Files

I’ve previously talked about using PNGDistill to optimize batches of images, but in today’s quick post, I’d like to show how you can use the tool to check whether images in your software binaries are well optimized. For instance, consider Chrome. Chrome uses a lot of PNGs, all mashed together a single resources.pak file. Tip:Continue reading “Finding Image Bloat In Binary Files”