Finding whether browser certificate is installed or not

[ArunB]

Is there any way that I can find out whether browser certificate is installed or not for a domain?

Suppose user requests a page at http://www.example.org/.
Can I find whether a browser certificate is installed for this domain or not using PHP?

[markup2go]

Not sure but you can access the $_SERVER array for a start.

Check for http or https and what port they are on. Then you can redirect them as needed.

[felgall]

If it is on https then it will only load if there is a valid certificate or the person loading the page specifically allows it without.

If it is on http then there can't be a certificate.

[ArunB]

Thank you felgall.

I am using https protocol. For enabling https protocol in my Apache server, I have created the key and cert files using OpenSSL.

So, even if the browser doesn't have the browser certificate installed, the page is getting loaded.

How can I stop browser from loading the Page if it doesn't have the certificate installed. And I am willing to generate separate certificate for each user. So, when I get request from the user, how can I get the certificate details on server side?