Given a GUID representing a user in Active Directory, how would I use this to determine the distinguished name?

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.

Answer 2

You can get the distinguishedName from the DirectoryEntry directly:

public string GetDN(DirectoryEntry de)  
{  
    return de.Properties["distinguishedName"].Value.ToString();  
}  

If you still need to bind via GUID you can do that as well:

public string GetDNviaGUID(Guid queryGuid)  
{  
    DirectoryEntry de = new DirectoryEntry("LDAP://<GUID=" + queryGuid + ">");  
    return de.Properties["distinguishedName"].Value.ToString();
}

The following properties and methods don't work when you bind via GUID or SID: ADsPath, Name, Parent, GetObject, Create, Delete, CopyHere, MoveHere.

You can get around this by retrieving the object via GUID, getting its distinguished name, and then binding using the DN.