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”

Understanding the Limitations of HTTPS

A colleague recently forwarded me an article about the hazards of browsing on public WiFi with the question: “Doesn’t HTTPS fix this?” And the answer is, “Yes, generally.” As with most interesting questions, however, the complete answer is a bit more complicated. HTTPS is a powerful technology for helping secure the web; all websites should beContinue reading “Understanding the Limitations of HTTPS”

Strict-Transport-Security for *.dev, *.app and more

Some web developers host their pre-production development sites by configuring their DNS such that hostnames ending in .dev point to local servers. Such configurations were not meaningfully impacted when .dev became an official Generic Top Level Domain a few years back, because even as smart people warned that developers should stop squatting on it, Google (the owner of theContinue reading “Strict-Transport-Security for *.dev, *.app and more”

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”

Certified Malice

One unfortunate (albeit entirely predictable) consequence of making HTTPS certificates “fast, open, automated, and free” is that both good guys and bad guys alike will take advantage of the offer and obtain HTTPS certificates for their websites. Today’s bad guys can easily turn a run-of-the-mill phishing spoof: …into a somewhat more convincing version, by obtainingContinue reading “Certified Malice”