How can I merge a SSL vhost config and a non-ssl vhost config for a same site?

I want my website to support both non-SSL and SSL access. What I had to do is copy the non-SSL config and change the port to 443 and add the SSL stuff. Not ideal to administrate!

Is there a way to merge those two configuration?

Here's my current config:

<VirtualHost *:80>
        ServerName www.site.tld
        ServerAlias site.tld

        suPHP_UserGroup site site
        DocumentRoot /path/to/site/www
        <Directory /path/to/site/www>
                AllowOverride All
                Order allow,deny
                allow from all
                Options -MultiViews
        </Directory>

        ExpiresActive On
        ExpiresByType image/gif "access plus 7 days"
        ExpiresByType image/jpeg "access plus 7 days"
        ExpiresByType image/png "access plus 7 days"
        ExpiresByType image/x-icon "access plus 7 days"
        ExpiresByType image/ico "access plus 7 days"
        ExpiresByType text/css "access plus 2 days"
</VirtualHost>

<VirtualHost *:443>
        ServerName www.site.tld
        ServerAlias site.tld

        suPHP_UserGroup site site
        DocumentRoot /path/to/site/www
        <Directory /path/to/site/www>
                AllowOverride All
                Order allow,deny
                allow from all
                Options -MultiViews
        </Directory>

        SSLEngine On
        SSLCertificateFile /etc/ssl/private/site.crt

        ExpiresActive On
        ExpiresByType image/gif "access plus 7 days"
        ExpiresByType image/jpeg "access plus 7 days"
        ExpiresByType image/png "access plus 7 days"
        ExpiresByType image/x-icon "access plus 7 days"
        ExpiresByType image/ico "access plus 7 days"
        ExpiresByType text/css "access plus 2 days"

</VirtualHost>

Running Ubuntu Server Karmic Koala.