I have a secure ASP .NET application requiring client certificates pulled from CAC cards which verifies users from Active Directory using System.DirectoryServices/LDAP. The application has been working fine for months now and I have not even touched the codebase since, but within the past week it has been denying everyone access.
I debugged the application on my workstation only to find that Page.Request.ClientCertificate is pulling absolutely no data... so of course it won't find SUBJECTCN in the certificate. Has there been any sort of regression in .NET 3.5 updates? What would cause this to just mystically stop functioning? I'm at a total and complete loss as to how to proceed.
Other important pieces of information:
ASP .NET impersonation is turned on.
Anonymous Authentication is turned on.
All other forms of authentication are off.
SSL is required.
Client certificates are required. ...
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