Firefox and Fiddler – Easier than Ever

In a world where software and systems seem to march inexorably toward complexity, I love it when things get simpler. Years ago, Firefox required non-obvious configuration changes to even send traffic to Fiddler. Eventually, Mozilla changed their default behavior on Windows to adopt the system’s proxy, meaning that Firefox would automatically use Fiddler when it was attached,Continue reading “Firefox and Fiddler – Easier than Ever”

Edge EV UI Requires SmartScreen

A user recently noticed that when loading Paypal.com in Microsoft Edge, the UI shown was the default HTTPS UI (a gray lock): Instead of the fancier “green” UI shown for servers that present Extended Validation (EV) certificates: The user observed this on some Windows 10 machines but not others. The variable that differed between those machines wasContinue reading “Edge EV UI Requires SmartScreen”

Fight Phish with Facebook (and Certificate Transparency)

As of April 30th, Chrome now requires that all certificates issued by a public certificate authority be logged in multiple public Certificate Transparency (CT) logs, ensuring that anyone can audit all certificates that have been issued. CT logs allow site owners and security researchers to much more easily detect if a sloppy or compromised Certificate Authority hasContinue reading “Fight Phish with Facebook (and Certificate Transparency)”

NET::ERR_CERT_INVALID error

Some users report that after updating their Operating System or Chrome browser to a more recent version, they have problems accessing some sites (often internal sites with self-signed certificates) and the browser shows an error of NET::ERR_CERT_INVALID. NET::ERR_CERT_INVALID means that a certificate was itself is so malformed that it’s not accepted at all– sometimes rejected byContinue reading “NET::ERR_CERT_INVALID error”

Google Internet Authority G3

For some time now, operating behind the scenes and going mostly unnoticed, Google has been changing the infrastructure used to provide HTTPS certificates for its sites and services. You’ll note that I said mostly. Over the last few months, I’ve periodically encountered complaints from users who try to load a Google site and get an unexpectedContinue reading “Google Internet Authority G3”

Chrome 59 on Mac and TeletexString Fields

Update: This change ended up getting backed out, after it was discovered that it impacted smartcard authentication. Thanks for self-hosting Chrome Dev builds, IT teams! A change quietly went into Chrome 59 that may impact your certificates if they contain non-ASCII characters in a TeletexString field. Specifically, these certificates will fail to validate on Mac, resulting inContinue reading “Chrome 59 on Mac and TeletexString Fields”

Get Help with HTTPS problems

Sometimes, when you try to load a HTTPS address in Chrome, instead of the expected page, you get a scary warning, like this one: Chrome has found a problem with the security of the connection and has blocked loading the page to protect your information. In a lot of cases, if you’re just surfing around,Continue reading “Get Help with HTTPS problems”

Chrome Deprecates Subject CN Matching

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 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, you’llContinue reading “Chrome Deprecates Subject CN Matching”

The Trouble with Magic

“Magic” is great… except when it isn’t. Software Design is largely about tradeoffs, and one of the more interesting tradeoffs is between user experience and predictability. This has come up repeatedly throughout my career and in two independent contexts yesterday that I’ll describe in this post. Developer Magic I’m working on a tiny UX changeContinue reading “The Trouble with Magic”