Question

I have an application which users Windows authentication in conjuction with ASPnet roles, so roles stored in a database but users on the windows domain.

I want to have a management page where admins add existing users to roles, does anyone know of a simple way I can check that the username input is valid in the active directory domain?

Answer 1

You could use the PrincipalContext class:

public bool UserExistsInAd(string username)
{
    using (var pc = new PrincipalContext(ContextType.Domain))
    {
        var up = UserPrincipal.FindByIdentity(pc, IdentityType.SamAccountName, username);
        return up != null;
    }
}

Obviously the account you have configured your ASP.NET MVC 3 application to run under in IIS must have sufficient privileges to access the Active Drectory.