Client Certificates and Logout

Back in May, I wrote about Client Certificate Authentication, a mechanism that allows websites to strongly validate the identity of their visitors using certificates presented by the visitor’s browser. One significant limitation for client certificate authentication is that there is no standards-based mechanism for a user to “log out” of a site that uses thatContinue reading “Client Certificates and Logout”

Web “Sessions” in Private Mode

I’ve written about Private Browsing Mode a lot previously, and I’ve written a bit about the behavior of “Session restore” previously, but one topic I haven’t covered is how “Sessions” work while in Private mode. Session Sharing Historically, one of the top-reported Private Mode issues was that users unexpectedly found that opening a new PrivateContinue reading “Web “Sessions” in Private Mode”

Local Data Encryption in Chromium

Back in February, I wrote about browser password managers and mentioned that it’s important to understand the threat model when deciding how to implement features and their security protections. Generally speaking, “keeping secrets from yourself” is a fool’s errand, so it’s a waste of time and effort to encrypt data if you have to storeContinue reading “Local Data Encryption in Chromium”

Seamless Single Sign-On

There are many different authentication primitives built into browsers. The most common include Web Forms authentication, HTTP authentication, client certificate authentication, and the new WebAuthN standard. Numerous different authentication frameworks build atop these, and many enterprise websites support more than one scheme. Each of the underlying authentication primitives has different characteristics: client certificate authentication isContinue reading “Seamless Single Sign-On”

Beating Private Mode Blockers with an Ephemeral Profile

Back in 2018, I explained how some websites use various tricks to detect that visitors are using Private Mode browsers and force such users to log-in. The most common reason that such sites do this is that they’ve implemented a “Your first five articles are free, then you have to pay” model, and cookies orContinue reading “Beating Private Mode Blockers with an Ephemeral Profile”

Same-Site Cookies By Default

The Chrome team is embarking on a clever and bold plan to change the recipe for cookies. It’s one of the most consequential changes to the web platform in almost a decade, but with any luck, users won’t notice anything has changed. But if you’re a web developer, you should start testing your sites andContinue reading “Same-Site Cookies By Default”

Challenges with Federated Identity in modern browsers

Many websites offer a “Log in” capability where they don’t manage the user’s account; instead, they offer visitors the ability to “Login with <identity provider>.” When the user clicks the Login button on the original relying party¬†(RP) website, they are navigated to a login page at the identity provider (IP) (e.g. login.microsoft.com) and then redirectedContinue reading “Challenges with Federated Identity in modern browsers”

Surprise: Undead Session Cookies

I’ve been working on browsers professionally for 12 of the last 15 years, and in related areas for 20 of the last 20, and over the years I’ve discovered enough surprises in browser behavior that they’re no longer very surprising. Back in April, I wrote up a quick post explaining how easy it is toContinue reading “Surprise: Undead Session Cookies”

Edge79+ vs. Edge18 vs. Chrome

Note: I expect to update this post over time. Last update: 10/8/2020. Compatibility Deltas As our new Edge Insider builds roll out to the public, we’re starting to triage reports of compatibility issues where Edge79+ (the new Chromium-based Edge, aka Anaheim) behaves differently than the old Edge (Edge18, aka Spartan, aka Edge Legacy) and/or GoogleContinue reading “Edge79+ vs. Edge18 vs. Chrome”