Set Server Side TLS to "modern"


#1

Understood that modifiction in MiaB is not recommended and overwritten after each update. Understand also that due to compatibility issues, MiaB uses mozillas default/moderate TLS configuration. However, can someone tell me what file (and its location) I have to change to enter the modern settings?


#2

The link you have provided is your best starting point:

This is what you have now in /etc/nginx/conf.d/ssl.conf :

# Reference client: htps://www.ssllabs.com/ssltest/analyze.html
ssl_prefer_server_ciphers on;
ssl_ciphers ‘ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA256:DHE-RSA-AES256-SHA:ECDHE-ECDSA-DES-CBC3-SHA:ECDHE-RSA-DES-CBC3-SHA:EDH-RSA-DES-CBC3-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:DES-CBC3-SHA:!DSS’;

# Cut out (the old, broken) SSLv3 entirely.
# This excludes IE6 users and (apparently) Yandexbot.
# Just comment out if you need to support IE6, bless your soul.
ssl_protocols TLSv1.2 TLSv1.1 TLSv1;

Compare with this from your link Nginx v.1.4.6 generator:

# modern configuration. tweak to your needs.
ssl_protocols TLSv1.2;
ssl_ciphers ‘ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256’;
ssl_prefer_server_ciphers on;

I would go another route - if you would do any modifications: I’d rather uninstall Nginx v.1.4.6 from the default Ubuntu 14 repo and add and install latest stable Nginx v.1.12.2 from Nginx repo - Then you could benefit the latest HTTP2 for speed and also security improvements. You’ll have to use ssl-config-generator for the version you choose to install.

As always this is not supported mod, any update may break your MIAB so test everything on a test VM and then move to production if your mail server is critical for you.