So I am registering users and I need to know they really are who they say they are. More importantly that they represent the company they say they represent.
I was told I can ask them to send me a verisign (or similar) certificate. Basically the company (the more reputable ones) emiting certificates are meant to have already made sure that person is who he says he is and/or really works for Company X Inc.
So when a user fills in his registration form, I ask for an email address, name, company name,etc. and I also ask for this certificate to be uploaded (with a short list of the actual certificates I will accept, e.g. Verisign Pro EV.)
So how do I then use this file to verify that the certificate is valid?