The TLS protocol is what encrypts traffic between two endpoints on the internet, and ensures that no one can look at what is being sent back and forth. This is important, especially when sending authentication credentials, which could be used by a nefarious third-party if they were intercepted. Over the years, there have been various improvements to the TLS protocol to improve the security and efficiency. These improvements are rolled out as new versions of the protocol, and there are currently 4 versions: 1.0, 1.1, 1.2, and 1.3, with 1.3 being the latest version, published in 2018.
As newer versions of the protocol are added, support for older versions is usually kept around for a while to give clients the chance to upgrade to software that can utilize the new version of TLS. Clients and servers negotiate the version they will use based on what versions each supports, opting to use the latest version possible. It is important that servers eventually phase out support for older versions, since attackers can force the server to use older versions if they are supported by the server, which can lead to attacks that are not possible in newer versions. Clients should also phase out support for older versions for the same reasons. All major web browsers have deprecated TLS 1.0 and 1.1 for a while, and are planning to remove support entirely later this year.
With the upcoming removal of TLS 1.0 and 1.1 from all major web browsers, and after analyzing our traffic logs over the past few months, we are confident that no legitimate clients connecting to the GitHub service are using these legacy TLS versions. We are therefore disabling support for TLS 1.0 and 1.1 on the NC State GitHub service on January 27th, 2021 at 11:00 AM.
Most clients should not notice this change, since they should be using at least TLS 1.2 already. Any clients that can no longer connect to the NC State GitHub service due to unsupported TLS versions will need to upgrade their software or firmware to support at least TLS 1.2.
If you have any questions or concerns regarding this change, please contact the NC State GitHub Service Team at firstname.lastname@example.org.