IETF officially ends support for TLS 1.0 and 1.1

CC-BY-CA Vadim Rybalko, based on meme

IETF Internet Engineers Working Group obsolete encryption protocols TLS 1.0 and 1.1. Relevant RFCs have officially received “historic” status with a note deprecated

Markup deprecated means that the IETF strongly discourages the use of these protocols. For security reasons, it is required to disable support for TLS 1.0 and 1.1 wherever possible. This is stated in the published RFC 8996… Why it is impossible to support the TLS 1.0 and 1.1 protocols is explained in detail in paragraphs 3, 4 and 5 of this document.

As explained by the IETF, removing support for older versions from libraries and software “reduces the attack surface, reduces the potential for misconfiguration, and makes the library and product easier to maintain.”

Along with the older versions of TLS, the Datagram TLS protocol (DTLS) version 1.0 (RFC 4347) is also deprecated, and only this, since version 1.1 did not come out.

TLS 1.0 is 22 years old this year. Since its adoption, it has become better understood how encryption protocols should be designed. Requirements for the reliability of ciphers have increased. Unfortunately, TLS 1.0 and 1.1 do not meet these requirements.

The worst thing is that TLS 1.0 and 1.1 do not support modern cryptographic ciphers. For example, when shaking hands, they necessarily use the SHA-1 hashing algorithm. In these versions of TLS, it is not possible to set a stronger hashing algorithm for ServerKeyExchange or CertificateVerify signatures.

A draft of this RFC 8996 was published on September 14, 2018. Among other things, it mentions that the SHA-1 algorithm with a cryptographic strength of 2 ^ 77 cannot be considered secure by modern standards: “2 ^ 77 operations [для атаки] – this is below the permissible safety limit. “

We are talking about the BEAST (Browser Exploit Against SSL / TLS) attack on TLS 1.0 and 1.1, or rather, on block ciphers, where the initialization vector for the message n the last encryption block of the previous message is used (n-1)

The developers of all major browsers immediately agreed to comply with the IETF recommendations.

Chrome browser was the first to drop support for older versions of TLS in January 2019… Starting with version 79 for legacy protocols, a warning was displayed in the DevTools console, and a complete shutdown was planned for version 81 of Chrome in March 2020 (preview versions – from January 2020). At the same time, the abandonment of TLS 1.0 and 1.1 was announced Microsoft, Mozilla and Apple

However, everything did not go according to plan. In March 2020 Firefox temporarily refused to remove support for TLS 1.0 and 1.1… Formally, this was done due to the coronavirus (see screenshot below), but in fact, the Mozilla developers were afraid that Google colleagues would back down and leave support for TLS 1.0 and 1.1, so Firefox will be the only browser without this support.

But in the end, support for old protocols in browsers was still disabled. If necessary, you can change the setting in Firefox security.tls.version.enable-deprecated

TLS 1.0 and 1.1 are gradually being removed from applications and services. Amazon, CloudFlare, GitHub, KeyCDN, PayPal and other web services have done this. Since January 15, 2020, support for old protocols has been disabled on Habr’s resources.

Similar Posts

Leave a Reply Cancel reply