apache 2.2 - Is there a way to set up SSL for a domain and all subdomains?

So, I have a domain with many subdomains. Let's say example.com, a.example.com, b.example.com, c.example.com, etc.

I want to host them from the same server with the same IP address.

I have my wildcard certificate and my base domain certification, star_example_com.crt and example_com.crt.

I'm trying to set up my Apache server to support SSL on the domain and sub-domains, but can't seem to get it working. The domain is fine, but the sub-domains are not.

Here's my config:

NameVirtualHost *:443 # To support SNI, although, apparently, this directive is deprecated

SSLStrictSNIVHostCheck off


    SSLEngine On
    SSLCertificateFile  /etc/apache2/ssl/example_com.crt
    SSLCertificateKeyFile   /etc/apache2/ssl/example_com.key
    SetEnvIf User-Agent ".*MSIE.*" nokeepalive ssl-unclean-shutdown


    DocumentRoot /var/www/html

        ErrorLog ${APACHE_LOG_DIR}/error.log
        CustomLog ${APACHE_LOG_DIR}/access.log combined


        
            Options Indexes FollowSymLinks MultiViews
            AllowOverride All

            Order allow,deny
            allow from all
        




    ServerAlias *.example.com
        SSLEngine On
        SSLCertificateFile      /etc/apache2/ssl/star_example_com.crt

        SSLCertificateKeyFile   /etc/apache2/ssl/star_example_com.key
        SetEnvIf User-Agent ".*MSIE.*" nokeepalive ssl-unclean-shutdown

        DocumentRoot /var/www/html

        ErrorLog ${APACHE_LOG_DIR}/error.log
        CustomLog ${APACHE_LOG_DIR}/access.log combined


        

            Options Indexes FollowSymLinks MultiViews
            AllowOverride All
            Order allow,deny
            allow from all
         

Am I missing something obvious here? All I want is to make sure that the right SSL cert is used for the domain and subdomains... everything is otherwise the same (this is a WordPress multisite, so it's all going to the same place in the end.

To be clear, I get an error when I access subdomains because I'm not getting the wildcard certificate.

To be further clear, I have over 80 subdomains. I'd like to avoid creating a VirtualHost for each one, if that's possible.

Any pointers?