My choices for TLS 1.2 and TLS 1.3

Intro

Enable TLS 1.2 now! Starting from March 2020, the most used browsers will no longer have the support for TLS 1.0 and TLS 1.1 protocols as has already happened for all versions of SSL in past years. If the applications that do not support TLS 1.2 or higher remain active, it will be possible to incur traffic loss. Later there will be new updates to the client browsers and it will no longer be possible to establish an HTTPS connection.

The main browsers announcements here:
• Chrome – from version 81
https://security.googleblog.com/2018/10/modernizing-transport-security.html
• Firefox – from march 2020
https://blog.mozilla.org/security/2018/10/15/removing-old-versions-of-tls
• Safari – from march 2020
https://webkit.org/blog/8462/deprecation-of-legacy-tls-1-0-and-1-1-versions
• Edge – Q2 2020
https://blogs.windows.com/msedgedev/2018/10/15/modernizing-tls-edge-ie11

TLS 1.2 on servers should have been a standard for years but TLS 1.3 has actually been available on browsers by default for a short time. Here is a summary of the minimum versions:
• Chrome
TLS 1.2 from v. 30 – TLS 1.3 from v. 67
• Firefox
TLS 1.2 from v. ESR 31 – TLS 1.3 from v. 60
• Safari
TLS 1.2 from v. 8 – TLS 1.3 from v. 13
• Edge
TLS 1.2 only up to v. 44 – both from v. 80 (chromium based)
• Opera
TLS 1.2 from v. 17 – TLS 1.3 from v. 57

Transport Layer Security (TLS), and its now-deprecated predecessor, Secure Sockets Layer (SSL), are cryptographic protocols designed to provide communications security over a computer network. Several versions of the protocols find widespread use in applications such as web browsing, email, instant messaging, and voice over IP (VoIP). Websites can use TLS to secure all communications between their servers and web browsers.

source: Wikipedia

Here my list of the ciphers

AES256-GCM-SHA384
AES128-GCM-SHA256
CHACHA20-POLY1305-SHA256

ECDHE-ECDSA-AES128-GCM-SHA256
ECDHE-ECDSA-AES256-GCM-SHA384
ECDHE-RSA-AES256-GCM-SHA384
ECDHE-ECDSA-CHACHA20-POLY1305
ECDHE-RSA-CHACHA20-POLY1305
ECDHE-RSA-ARIA256-GCM-SHA384
ECDHE-RSA-AES128-GCM-SHA256
ECDHE-RSA-ARIA128-GCM-SHA256
ECDHE-ECDSA-AES256-SHA384
ECDHE-ECDSA-AES128-SHA256
DHE-RSA-AES256-GCM-SHA384
DHE-RSA-AES128-GCM-SHA256

Why did I choose this order?

I read lots of documents and there is no only one view about the order. I selected this order of ciphers with these simple reasons:

• ECDHE > DHE
• GCM > CHACHA20 > others
• AES256 > AES128
• ECDHE-ECDSA-AES128-GCM-SHA256 is the “most popular” cipher for TLS 1.2 so I put it at the top of the list

The steps to be performed in a nutshell

• Here you can make a quick check of which versions of SSL / TLS are available on Public URLs.
• Enable TLS 1.2.
• Enabling TLS 1.3 is strongly recommended.
• Disable TLS 1.0 and 1.1 and all versions of SSL.
• Disable ECC curves < P_256
• Enable secure renegotiation.
• Enabling OCSP Stapling is optional but recommended.
• Enabling HSTS is optional but recommended. The impact of this configuration must be well assessed!
• CAA record on DNS configuration is optional but recommended.
• In order to use the DHE ciphers you need to configure the DH key.

Retro compatibility

To have compaibility with old systems (Win7/8.1, Safari 6-8, iOS 6/7/8.4, OSX 10.9/10.10) you can add this cipher:

ECDHE-RSA-AES256-CBC-SHA384