Is it possible to restrict windows authenticated users in an ASPNet app to specific domains?

Question

I'm in the process of pulling a classic ASP app into Mvc2. I'll be deploying to an intranet and have been asked to enable support for Windows Authentication. The network I'll be deploying to has a few AD Domains and I'll only need to integrate with one in particular. Is it possible to use Windows Authentication and only allow authentication within a particular domain?

Along those same lines, it's not uncommon for a user to have an account in multiple domains (the account names themselves are typically different) - in the event a user logs in with an "unsupported" domain I'd like to kick them to a login form. Is this possible simply using Windows Auth or am I better off looking for an alternative?

Answer 1

Pro Tip:

Whatever you do don't implement Windows Authentication via IIS. Have a Forms Authentication page in your MVC app but use the LDAP authentication provider. This way you avoid the differences between how browsers implement Windows Authentication (only works well in IE and that's not a great reason).

Answer 2

The question "Is it possible to use Windows Authentication and only allow authentication within a particular domain?" has always has one and only one answer in my consulting experience: the answer is the permissions that you set for authenticated resources.

I've rarely found a deployment where there isn't some file, folder, server, COM+ object, SQL Role or database table that can't be "locked down" to only allow access by the subset of users you're targeting (e.g. "DOMAIN\Domain Users"):

• Set permissions on the ASPX files (or the folder containing them, along with inheriting to the files) that are the "front door" (and optionally, all the others) so that they're only accessible to users in the "Domain Users" group for the allowed domain
• restrict logon rights on the server that hosts the web site, so that only the Domain Users group have the appropriate rights - depending on the authentication provider used, this could be "allow logon locally" or "access this computer from the network"
• set permissions at some layer of Component Services
• restrict the SQL Server roles so that only "Domain Users" have the ability to read & execute the necessary database objects