Subject Alternative Names, or SAN SSL certificates, enable the protection of a specified list of multiple hosts via a single SSL certificate. The SAN extension has comprised part of the X509 certificate standard since 1999 and earlier, however the certificate type was not widely used as a part of standard webpage creation until the launch of Microsoft’s Exchange Server in 2007. This server uses Subject Alternative Names as a great way to simplify the configuration of servers. Read on to learn about how SAN SSL certificates are used, and some of the benefits of a SAN certificate.
SAN SSL certificates have three major uses. The first is to secure a number of host names that utilize different base domains with just one SSL certificate. While wildcard certificates are able to protect all of the first-level sub-domains for an entire domain, such as blog.site.com, wildcard certificates cannot protect www.site.com in addition to www.site.net. SAN SSL certificates can protect a .com domain, a .net domain and more.
Another use is to virtually host more than one SSL site on one single IP address. Typically, the process of hosting multiple SSL sites on one server requires a different IP address for each site, but an SSL certificate with Subject Alternative Names is able to solve this problem. Apache and Microsoft IIS 6 are both able to virtually host HTTPS utilizing the SAN SSL certificates.
The final use is to simplify the Exchange Server 2007 configuration of SSLs. Utilizing a SAN certificate prevents a great deal of hassle when configuring the IP addresses. Without a SAN certificate, each IP address is bound to a different certificate, and a large number of PowerShell commands are necessary just to put it all together.
SSL certificates definitely have their weaknesses. Luckily, with the evolution of SAN SSL certificates, web administrators are able to protect a number of sites with just one SSL certificate. This eliminates a great deal of the frustration involved with hosting multiple sites. SAN SSL certificates have definitely found their place in the world of web design.