My "in-house" Exchange Server has an SSL UC/SAN Certificate from DigiCert to secure the OWA access.
I would like to install an SSL Certificate also in my Cisco ASA Firewall in order the remote users to access the VPN with SSL Certificate.
And in the near future, I would like to add an SSL to my Web Site which is currently under construction.
Q1) Is it possible to use the existing Certificate of Exchange Server by adding the subdomain assigned to the VPN?
Q2) If yes, and a user who is accessing the Exchange OWA opens the browsers SSL padlock will he be able to see all the subdomains assigned to this SSL Certificate?
Since, in that case, it will help a possible hacker to see the available subdomains.
Q3) Security wise, is it recommended to have one Certificate with various subdomains to cover various applications and Services or is it better to issue different SSL Certificates for each platform/service?
Thank you in advance,