SSL certificate for internal and external usage
security, ssl, web
Solution
You will need two SSL certificates, and the one for the intranet server will have to be self-signed, because certificate authorities are prohibited from signing certificates for internal domains (as there is no way to verify ownership of such a domain).
It is ordinarily possible to create a single SSL certificate that is valid for multiple domains (by using the Subject Alternate Name extension). However, again, a CA cannot sign one unless they can validate all of the domains it claims to be valid for.
Problem
Let's suppose I have a web application that is accessed externally via http://webapp.mydomain.com and internally via http://webapp.intranetservername/ Do I need two SSL certificates? Or can the same SSL certificate be used?