I have asked previous questions but I think I got too far into pre-conceived notions that I ruled out other options. I'm going to start over:
I have tools which are developed and maintained in HTML and JavaScript. What I would like to do is automate the collection of user data. The users are currently filling in their information and we are storing them in cookies for 6 months. However, If I can have them skip the step of manually inputting this information it'll be a small time savings.
If I'm going to be using something server-side I'll be using Microsoft Web Server 2012 with IIS 8.5.
What I would like to know is: What is the best approach in terms of language?
Is the best approach a client AJAX call to ASP.Net page which writes the user data back into JSON format? Should I try authenticated queries or non-authenticated queries? I'm lost.
I need recommendations and some guidance with where and how to get started/what I need to learn.
Update: To be clear, I'm looking for a solution that will be external to my existing code. Something that I can access externally (e.g. AJAX comes to mind) and have it spit back (AD data point indicators): givenName, sn, displayName, telephoneNumber, title.