Hi

Ive been given a project in which I need to make a web page which will only allow access if the user has a certain certificate (from a certain ca)( previously issued for another purpose)
The website then needs to be able to take information from the certificate such as the DN, name etc etc...
I dont have a clue where to start...
Do i need to use any specific software?
Do i need to use a specific language to write the website in ?
I will most likely be using linux with apache webserver.

thanks in advance