What is a Wildcard SSL certificate?
A Wildcard SSL certificate secures your website URL, and an unlimited number of its subdomains. A single Wildcard certificate can secure both www.coolexample.com, and blog.coolexample.com.
Wildcard certificates secure the common name and all subdomains at the level you specify when you submit your request. Just add an asterisk (*) in the subdomain area to the left of the common name.
If you configure *.coolexample.com, you can secure:
If you configure *.www.coolexample.com, you can secure:
Wildcard certificates secure websites the same as regular SSL certificates, and requests are processed using the same validation methods. However, some Web servers might require a unique IP address for each subdomain on the Wildcard certificate.
What is the difference between a Premium Extended Validation (EV) Certificate and a Deluxe SSL Certificate?
SSL Certificate Renewal - Apache 1.3 / 2.x
SSL Certificate Renewal - Parallels Plesk Panel
Generating a Certificate Signing Request
Information About Requiring the SHA-2 Hash Function
Where can I get information about my SSL's configruation?