Apache Cookbook, 2nd Edition

Wildcard Certificates

Problem

You want to use a single certificate for multiple hostnames in the same domain.

Solution

Use a wildcard certificate, which works for any name within a particular domain, such as “*.example.com.”

Discussion

Using the technique described in Recipe 7.2, create a certificate with a Common Name of *.example.com, where example.com is the domain for which you wish to use the certificate. This certificate will now work for any hostname in the example.com domain, such as www.example.com or secure.example.com.

On many browsers, however, the certificate will not work for example.com or for one.two.example.com, but only for hostnames strictly of the form hostname.example.com.

Most certificate authorities will charge considerably more to sign wildcard certificates. This is not because it is somehow more complicated to sign these certificates, but because it is a simple business decision, based on the fact that buying a wildcard certificate means that you don’t need to buy multiple single-host certificates.

See Also

• Recipe 7.2