Redirect all HTTP requests (non-www & www, subdomains) to HTTPS - apache

Question

I want to be able to redirect all visitors to a website & its subdomains to HTTPS like the following:
http://example.com -> https://www.example.com
http://www.example.com -> https://www.example.com
http://sub.example.com -> https://sub.example.com
http://www.sub.example.com -> https://sub.example.com
https://www.sub.example.com -> https://sub.example.com
Other redirects:
w (or ww, wwww, etc).example.com -> https://www.example.com
w (or ww, wwww, etc).sub.example.com -> https://sub.example.com
The redirects should be a cacheable HTTP 301 redirect. The configuration used is Apache 2.4.10 + mod-spdy, with Strict-Transport-Security (Plus a wildcard SSL cert).
Currently use the following in .htaccess:
RewriteCond %{SERVER_PORT} !^443
RewriteCond %{HTTP_HOST} ^example\.com$ [OR]
RewriteCond %{HTTP_HOST} ^www\.example\.com$
RewriteRule ^ "https://www.example.com%{REQUEST_URI}" [R=301,L]
RewriteCond %{SERVER_PORT} !^443
RewriteCond %{HTTP_HOST} ^sub\.example\.com$
RewriteRule ^ "https://sub.example.com%{REQUEST_URI}" [R=301,L]
I've been using spdycheck.org to test this, it works fine for the main domain, with the subdomains I get the following message:
HTTP Traffic Allowed
This website can still be access via HTTP. HTTP
does not provide any widely implemented mechanism for using other
protocols like SPDY. Only traffic over SSL/TLS using the NPN Extension
can be optimized with SPDY. By allowing HTTP traffic, this website is
not even offering SPDY capable browsers the choice of using SPDY. If
possible, this website should redirect all http:// to https://,
ideally with a cachable HTTP 301 redirect.
What's a good way to accomplish this? I could modify httpd.conf if required also.

Answer 1

If you're doing it in your httpd.conf, put in something like:
<VirtualHost _default_:80>
RewriteEngine On
RewriteRule ^/(.*) https://%{HTTP_HOST}/$1 [NE,L,R=301]
</VirtualHost>
After all of your virtual hosts, and ensure that your other virtual hosts are port 443 only. This will make this redirect the global http vhost that will redirect each page individually to HTTPS and give a 301 redirect.