Hi, Firefox supports TLS 1.2 out of the box and you don't have to change anything to enable it. You can also use a site like https://www.ssllabs.com/ssltest/viewMyClient.html to check the capabilities of your browser.

There are TLS settings prefs on the about:config page that specify the minimum and maximum TLS version.

• security.tls.version.min = 1
• security.tls.version.max = 3

1 means TLS 1.0 2 means TLS 1.1 3 means TLS 1.2 (default) 4 means TLS 1.3;

• http://kb.mozillazine.org/security.tls.version.*

vangoghvan said

When i check "security.tls.version.min" it's shown "Value 1". Is that the right value to TLS 1.2 ?

The security.tls.version.min is the minimum as the security.tls.version.max should be set at 3 which is the default for to have TLS 1.2.

Present since Firefox 27.

• Bug 861266 - Implement TLS 1.2 (RFC 5246) in Gecko (Firefox, Thunderbird), on by default

Note that TLS 1.3 is still not enabled by default in current releases.

Doesn't your Linux distribution support more recent Firefox versions?

• https://www.mozilla.org/en-US/firefox/52.5.3/system-requirements/
• https://www.mozilla.org/en-US/firefox/57.0.4/system-requirements/