Enforce https + remove www + redirect aliases to main domain name on Apache 2 - apache

Question

Client site uses several domains leading to the same content, which is bad for SEO ("duplicated content").
example.com, www.example.com, foo.com, foo.example.com, www.foo.com and www.foo.example.com
Also, the site must now use https on all requests.
So the task now is to enforce the sole use of https://foo.example.com as the SSL certificate is for *.example.com. All other domains should be redirected to https://foo.example.com
I'm trying to implement these requirements via url rewriting in the website's root folder .htaccess file.
Rewritecond %{HTTP_HOST} !^example\.com
RewriteRule ^(.*)$ https://example.com/$1 [R=301,L]
It works, except for one use case: http://example.com
Requests pointing to http://example.com/hello do not get rewritten to the https://example.com.
So I tried
RewriteCond %{HTTPS} !^on [OR]
Rewritecond %{HTTP_HOST} !^example\.com
RewriteRule ^(.*)$ https://example.com/$1 [R=301,L]
But i get a "redirection loop" error. It means the conditions are always true, but why?
server details
Server: LAMP (Apache 2) on Red Hat Enterprise Linux Server release 6.5
UPDATE
I think my rewriting rules are correct, the issue occurs upstream. System administrator informed me that their network redirects 443 requests to the local machine's :80 port. Also, phpinfo() on a https url shows no presence of SSL flags ( HTTPS= on does not appear in phpinfo()).