Vircom has made a product that can do that. The authentication source can
be a text file, an ODBC data source, a RADIUS server or the NT SAM. The
realm can also be changed to allow authentication against different source
within the same site. Since most of the security settings are stored in an
text file, it can also be remotely managed by FTPing/copying the file to the
IIS server.
The name of the product is the VOP ISAPI Authentication Filter. More
information is available from our WWW site at http://www.vircom.com. You're
also welcome to email me or sales@vircom.com if you have specific questions.
Richard Lachance.
General Manager, Vircom Inc.