Bulletproof TLS Newsletter

Bulletproof TLS Newsletter is a free periodic newsletter bringing you commentary and news surrounding SSL/TLS and Internet PKI, designed to keep you informed about the latest developments in this space. Maintained by Hanno Böck.

The Electronic Frontier Foundation (EFF) has announced the deprecation of the HTTPS Everywhere plug-in. Instead it recommends that users enable HTTPS-only modes provided by modern browsers.

HTTPS Everywhere is a popular and commonly recommended security plug-in for browsers. It comes with a list of sites that support HTTPS and will make sure that the browser will redirect users to the HTTPS version if available.

While this improved security and avoided some unencrypted and unprotected connections, it has limitations. For example, it only redirects users for hosts included in the plug-in’s list.

Lately, major browser vendors have implemented HTTPS-only modes, starting with Firefox last year. Chrome and Edge also have added similar features. While similar in their goal, these HTTPS-only modes work differently than the HTTPS Everywhere plug-in.

By default, they don’t automatically connect to those hosts that only offer HTTP at all. In this mode, browsers will only connect via HTTP after manual confirmation by the user. This approach only became feasible because large parts of the web are now encrypted by default.

In a sense, the deprecation of HTTPS Everywhere shows how far the HTTPS-only web has come. The HTTPS Everywhere plug-in is thus no longer needed due to the success of its original idea.

Short news

• GitHub announced that it is deprecating the unencrypted Git protocol. Git connections can operate via various protocols. The git:// protocol is unencrypted, and there is no specified way to use it with TLS. TLS protection can be used via HTTPS; alternatively, Git supports encrypted connections via SSH. Apart from the Git protocol deprecation, GitHub will also disable support for some older cryptographic algorithms via SSH.
• Curl version 7.79.0 contains several security fixes, two of them for flaws in the STARTTLS implementation. These are similar to various vulnerabilities recently published in STARTTLS implementations in a Usenix paper that we covered last month (the author of this newsletter coauthored that paper).
• Go 1.17 made some changes in the way TLS cipher suites are selected, as explained by Filippo Valsorda in a blog post. The new Go version prefers ECDSA over RSA, AEAD ciphers over CBC, and avoids some problematic ciphers.
• A blog post by Omid Azizi explains how to use the Linux kernel eBPF functionality to trace TLS connections.
• On September 30, the root certificate originally used by Let’s Encrypt will expire. This may cause some hiccups, particularly for setups that manually configure the intermediate certificate and don’t use the one provided by the ACME automation. Scott Helme explains the details in a blog post.
• A blog post by Sophos gives a detailed explanation of two recently fixed OpenSSL vulnerabilities.
• An episode of the Heavy Networking podcast from Packet Pushers covered TLS 1.3.
• A blog post by Samuel Lucas gives some recommendations for cryptography learning resources.
• The recently published book Real-World Cryptography, written by David Wong, gives an introduction to and overview of many modern cryptographic concepts.
• A research paper published at CCS analyzes man-in-the-middle (MITM) phishing toolkits.
• Firefox 92 introduces support for HTTPS DNS Resource Records (RRs).
• The Security. Cryptography. Whatever podcast interviews Ryan Sleevi from Google and discusses Certificate Authorities.