This is apparently the default and recommended by Mozilla's server-
side SSL configurator also recommends. This lets the client choose
the ciphers best for them (and the ciphers in TLS 1.2 and 1.3 are
not currently known to be dangerous).
The old default has not been changed in eight years and I see that
there have been some discussions over the years about this. I will
change this from the slightly extreme 1400 bytes to 4k (nginx def-
ault is still 16k so this is more "optimal" for HTML/CSS content).
See: https://github.com/igrigorik/istlsfastyet.com/issues/63
I changed these yesterday when editing the truthy values, but acco-
rding to ansible-link we can just rely on them being true or false
without comparing.
According to Ansible we can use yes, true, True, "or any quoted st-
ring" for a boolean true, but ansible-lint wants us to use either
true or false.
See: https://chronicler.tech/red-hat-ansible-yes-no-and/
After the inital acme.sh script is downloaded and bootstrapped we
can remove it. If a host already has been bootstrapped then there
is no need to download it and do it over again.
Instead of manually creating our own self-signed certificate we can
use the one created automatically by the ssl-cert package on Debian.
This is only used by the dummy default HTTPS vhost.
This parameterizes the HTTP Strict Transport Security header so we
can use it consistently across all templates. Also, it updates the
max-age to be ~1 year in seconds, which is recommended by Google.
See: https://hstspreload.org/
The certbot-auto client that I've been using for a long time is now
only supported if you install it using snap. I don't use snap on my
systems so I decided to switch to the acme.sh client, which is imp-
lemented in POSIX shell with no dependencies. One bonus of this is
that I can start using ECC certificates.
This also configures the .well-known directory so we can use webroot
when installing and renewing certificates. I have yet to understand
how the renewal works with regards to webroot, though. I may have to
update the systemd timers to point to /var/lib/letsencrypt/.well-known.
