Question

Given a GUID representing a user in Active Directory, how would I use this to determine the user’s “distinguished name” using C#?

The GUID is retrieved earlier in our application using directoryEntry.Guid;
MSDN Link

Answer 1

As you’ve made it clear a GUID is what you’re searching on, try this:

using System;
using System.DirectoryServices.AccountManagement;

public static class DomainHelpers
{    
    public string GetDistinguishedName(string domain, string guid)
    {
        var context = new PrincipalContext(ContextType.Domain, domain); 
        var userPrincipal  = UserPrincipal.FindByIdentity(context, IdentityType.Guid, guid);

        return userPrincipal.DistinguishedName;
    }
}

I’ve used this with IdentityType.Name so can’t be sure it’ll work for IdentityType.Guid, but it’s worth a try.