Bulletproof TLS Newsletter
IETF formally deprecates TLS 1.0 and 1.1
31 March 2021
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. Received monthly by more than 50,000 subscribers. Written by Hanno Böck.
The Internet Engineering Task Force has published RFC 8996, which officially deprecates the old TLS versions 1.0 and 1.1. These old versions have inherent security weaknesses that can only be fixed by moving to a newer protocol version.
This move is not a surprise; it merely codifies what is already widespread practice. Back in late 2018, all major browser vendors announced plans to deprecate these old TLS versions, and web clients today usually don’t initiate connections with TLS 1.0 and 1.1.
Together with the old TLS versions, two other RFCs are marked as obsolete. One is RFC 5469, which specifies DES and IDEA cipher suites that were never allowed within TLS 1.2 and thus are no longer usable. The other is RFC 7507, which specifies a downgrade protection mechanism called Signaling Cipher Suite Value (SCSV) that was used to prevent client downgrades to previous TLS versions on connection failures. TLS 1.3 introduced a different version negotiation and downgrade protection mechanism and thus made SCSV obsolete.
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Short news
- Void Linux announced a switch back from LibreSSL to OpenSSL. Void Linux was one of the few Linux distributions using the LibreSSL library by default.
- OpenSSL published version 3.0.0 alpha 13.
- Google announced that it will start using a new cross-signed certificate for their services. One of Google's roots expires in December 2021; a cross-certificate from a well-established root is needed to continue to support older devices.
- Chrome’s navigation bar will default to HTTPS if someone enters a URL without a protocol prefix. However, it still falls back to HTTP if an HTTPS connection doesn’t succeed.
- A blog post on CryptoHack explains how to recover a private key from an incomplete PEM representation of the key.
- Researchers from Inria and Wire have presented hacspec, a representation language to formally specify cryptographic algorithms for their use within Rust.
- Chrome has started to enable SCT auditing. SCTs are part of the Certificate Transparency concept and confirm that a certificate was submitted to a CT log. Ivan Ristić explained SCT auditing in a blog post at Hardenize. Emily Stark from Google also explained the concept on Twitter.
- GnuTLS published version 3.7.1, which fixed two use-after-free vulnerabilities.
- ENISA published an overview of the current state of post-quantum cryptography.
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