Unless you have a massively underpowered computer, the mere fact of using SSL isn't likely to cause such a dramatic performance problem. Even SSL handshakes are pretty cheap these days. It sounds like there might be something else going on, possibly triggered by having added SSL.
Posting your webserver configuration files is a good place to start.
No, sorry, my ENglish might not be clear sometimes...
I wanted to say that when there is no configuration of ssl for a vhost, it works quickly ; but if a vhost is configured as well for ssl mode, then, even if I do not redirect the queries (with rewrite directive into httpd) to https, it is very long like foir ssl mode. In other words, the fact that doku is slow with doesn't means other vhost are fast. The problem is also for other vhost.
This is strange : without redirecting to ssl, the fact that ssl is configured for the same vhost should not interfere if you access it via simple http.
time curl -I https://dokuden.dennet.eu/
HTTP/1.1 302 Found
Date: Tue, 07 Mar 2023 07:51:47 GMT
Server: Apache/2.4.55 (Fedora Linux) OpenSSL/3.0.8 mod_perl/2.0.12 Perl/v5.36.0
The /server-info is not responding to dokuden. So this is just the proof of what I tried to say : normally my server is fast, since https is implemented in, the sites referring to ssl became far too long. You can make a trial with the cloud at nuage.dennet.eu
How do you know that ?...
So to my opinion, their might be something to improve into the applications as you suggest (doku, cloud, drupal), in apache itself, but also in the ssl parameters, because everything is fast without ssl.
So far, you have only demonstrated that your server generates a slow response when the response is generated by PHP. That is including your homepage:
Any response which is generated purely by Apache (not invoking PHP) is fast.
I'm completely certain that whatever PHP code you have running is causing the slowdown. This may be a side effect of having HTTPS set up on your website, but it is fundamentally an issue in the PHP application, not in the the workings of Apache or SSL. The mere presence of HTTPS in your Apache configuration doesn't suddenly make PHP slow.
But, anyway, beside my problems, could you give us, regarding strictly ssl, what are the parameters which can be be adjusted to make sure that a site is optimised from ssl point of view (if the response is not too complicated of course).