Provide Auto Login via Active Directory Windows Authentication on Open Source ASP.NET Web Application

I have a Windows Server 2012 domain named adatum.com. I also have a Windows Server 2008 R2 as Web Server. Web Server has MSSQL Server 2008 R2 installed. I installed an open source ASP.NET forum software on webserver and website is accessible using forum.adatum.com. Instead of clicking login and filling authentication form, I want to use single sign on solution. When a user sign on his client computer and browses [login to view URL], if possible he should not need to click login again. If this something you can deliver quickly this is a good opportunity for you. I also have many upcoming work like this. Users from Eastern Europe will be preferred. Max budget for this task is 20 USD. No upfront payments. No milestones. Payment will be provided only upon successful result. Contractor may need to modify source code of application. I'll provide the guidelines that i found but I expect final work from them. You will be given Teamviewer access to my environment. IN YOUR FIRST LINE OF APPLICATION, TELL ME THAT YOU ACCEPT MY TERMS, OTHERWISE I WILL IGNORE YOUR BID. Best offer with best feedback gets the job.