The Strict HostnameVerifier works the same way as Sun Java 1.4, Sun Java 5, Sun Java 6-rc. It's also pretty close to IE6. This implementation appears to be compliant with RFC 2818 for dealing with wildcards.
The hostname must match either the first CN, or any of the subject-alts. A wildcard can occur in the CN, and in any of the subject-alts. The one divergence from IE6 is how we only check the first CN. IE6 allows a match against any of the CNs present. We decided to follow in Sun Java 1.4's footsteps and only check the first CN. (If you need to check all the CN's, feel free to write your own implementation!).
A wildcard such as "*.foo.com" matches only subdomains in the same level, for example "a.foo.com". It does not match deeper subdomains such as "a.b.foo.com".
@author Julius Davies