Articles I've written

Overriding HTTP response content in Chrome
October 5, 2023

The Chrome browser (and others like Edge) allows you to override both HTTP response headers and the response content. I've previously written about overriding the headers for testing purposes, let's see how you can override the body, or the content itself, as well. Starting with Chrome 117 (released in September 2023) it's also greatly simplified.

(read more…)

Validity period of HTTPS certificates issued from a user-added CA is essentially 2 years
August 18, 2023

Since 2020, maximum lifetime of HTTPS certificates is limited to 1 year, exactly 398 days. I've previously written about the history and the reasons behind the change. But the reduced lifetime applies only to certificates issued from a public certification authority (CA) added to the operating system's or the browser's trusted root store by the vendor.

(read more…)

Overriding HTTP response headers in Chrome
May 4, 2023 (updated October 5, 2023)

Starting with Chrome 113 (and in other browsers like Edge), you can override HTTP response headers, or add a new one. This is handy as you can override e.g. some security headers for testing. The HTTP response header override will be applied before things like CSP are processed so you can modify the Content Security Policy for the page for example.

(read more…)

Maximum HTTPS certificate lifetime to be 1 year soon
February 21, 2020 (updated September 2, 2020)

In February 2020 at the CA/Browser Forum in Bratislava, Slovakia (and later officially), Apple has announced that starting September 1st, 2020, maximum TLS certificate lifetime in Safari (and probably in the whole macOS and iOS and all apps) will be just 1 year, 398 days exactly. Apple's change has been followed by both Chrome and Mozilla later that year. That's very good news. But why?

(read more…)

Disable TLS 1.0 & 1.1 today
October 16, 2018 (updated March 23, 2021)

Microsoft, Google, Apple & Mozilla announced yesterday that they're removing TLS 1.0 and TLS 1.1 protocols from Internet Explorer, Edge, Chrome, Safari & Firefox browsers in the beginning middle of 2020. Your visitors most probably don't use them already so you can disable them in your server configs today. But let's verify that first using the “Handshake Simulation” tool available in the SSL Labs Server Test.

(read more…)

Browsers are hiding the padlock and it's a Good Thing™
October 15, 2018 (updated October 21, 2023)

Magical properties are often attributed to the padlock icon 🔒 which marks “secure” pages. For example, you'll often hear that the icon indicates trustworthy websites that won't abuse your data and passwords. The padlock is gradually being removed and that's a Good Thing™. But why?

(read more…)

Not secure: Chrome and HTTP websites
July 25, 2018 (updated September 13, 2023)

Chrome started marking all HTTP websites as Not secure yesterday (on my birthday, what a gift!) with their release of Chrome 68. The treatment is not a red warning yet, just a gray (i). And there's a lot of busy czech websites getting that treatment. And how did we get here anyway and what's next?

(read more…)

Chrome, ERR_SPDY_PROTOCOL_ERROR, and an invalid HTTP header
August 28, 2017 (updated January 25, 2023)

When migrating your site to a more performant HTTP/2 protocol, it may happen that Chrome will not load a page and will display This site can’t be reached with ERR_SPDY_PROTOCOL_ERROR instead. HTTP/2 is derived from the earlier SPDY protocol, that's probably why the error message doesn't mention HTTP/2 at all. I'll show you how to figure it out with chrome://net-export.

(read more…)

All articles