How to know if DirectoryEntry is a user or a group?

Question

Hi,

I have the following code to create a tree from the current AD :

public static ActiveDirectory GetActiveDirectoryTree(string pathToAD = "")
{
    DirectoryEntry objADAM = default(DirectoryEntry);
    // Binding object. 
    DirectoryEntry objGroupEntry = default(DirectoryEntry);
    // Group Results. 
    DirectorySearcher objSearchADAM = default(DirectorySearcher);
    // Search object. 
    SearchResultCollection objSearchResults = default(SearchResultCollection);
    // Binding path. 
    ActiveDirectory result = new ActiveDirectory();
    ActiveDirectoryItem treeNode;

    // Get the AD LDS object. 
    try
    {
        if (pathToAD.Length > 0)
            objADAM = new DirectoryEntry();
        else
            objADAM = new DirectoryEntry(pathToAD);
        objADAM.RefreshCache();
    }
    catch (Exception e)
    {
        throw e;
    }

    // Get search object, specify filter and scope, 
    // perform search. 
    try
    {
        objSearchADAM = new DirectorySearcher(objADAM);
        objSearchADAM.Filter = "(&(objectClass=group))";
        objSearchADAM.SearchScope = SearchScope.Subtree;
        objSearchResults = objSearchADAM.FindAll();
    }
    catch (Exception e)
    {
        throw e;
    }

    // Enumerate groups 
    try
    {
        if (objSearchResults.Count != 0)
        {
            //SearchResult objResult = default(SearchResult);
            foreach (SearchResult objResult in objSearchResults)
            {
                objGroupEntry = objResult.GetDirectoryEntry();
                result.ActiveDirectoryTree.Add(new ActiveDirectoryItem() { Id = objGroupEntry.Guid, ParentId = objGroupEntry.Parent.Guid, AccountName = objGroupEntry.Name, Type = ActiveDirectoryType.Group, PickableNode = false });

                foreach (object child in objGroupEntry.Properties["member"])
                {
                    treeNode = new ActiveDirectoryItem();
                    var path = "LDAP://" + child.ToString().Replace("/", "\\/");
                    using (var memberEntry = new DirectoryEntry(path))
                    {
                        if (memberEntry.Properties.Contains("sAMAccountName") && memberEntry.Properties.Contains("objectSid"))
                        {
                            treeNode.Id = Guid.NewGuid();
                            treeNode.ParentId = objGroupEntry.Guid;
                            treeNode.AccountName = memberEntry.Properties["sAMAccountName"][0].ToString();
                            treeNode.Type = ActiveDirectoryType.User;
                            treeNode.PickableNode = true;
                            treeNode.FullName = memberEntry.Properties["Name"][0].ToString();

                            byte[] sidBytes = (byte[])memberEntry.Properties["objectSid"][0];
                            treeNode.ObjectSid = new System.Security.Principal.SecurityIdentifier(sidBytes, 0).ToString();

                            result.ActiveDirectoryTree.Add(treeNode);
                        }
                    }
                }
            }
        }
        else
        {
            throw new Exception("No groups found");
        }
    }
    catch (Exception e)
    {
        throw new Exception(e.Message);
    }

    return result;
} 

The problem is that using (var memberEntry = new DirectoryEntry(path)) returns DomainUsers as a user to this tree and Im not sure if this is correct?

Say that I store the sidId for the DomainUsers node and then sends it to the following method :

public static Boolean GetActiveDirectoryName(string sidId,out string samAccountName,out string fullName)
        {
            samAccountName = string.Empty;
            fullName = string.Empty;


            if (sidId != null && sidId.Length > 0)
            {
                var ctx = new System.DirectoryServices.AccountManagement.PrincipalContext(ContextType.Domain, null);
                using (var up = UserPrincipal.FindByIdentity(ctx, IdentityType.Sid, sidId))
                {
                    samAccountName = up.SamAccountName;
                    fullName = up.Name;

                    return true;
                }
            }
            return false;
        }

The up will be set to null? If I choose another user in the AD then it workes just fine. I suspect that the DomainUsers is a group, but how do I check for this on then DirectoryEntry?

BestRegards

Answer 1

Off the top of my head: Have you considered checking Schema properties of the returned result? I'm thinking you could easily figure a group by using DirectoryEntry.SchemaEntry.Name. It should return group if your schema entry is a group.

Reference: MSDN: DirectoryEntry.SchemaEntry

---

Just out of curiosity and a bit off topic in your code above:

 if (pathToAD.Length > 0)
      objADAM = new DirectoryEntry();
 else
      objADAM = new DirectoryEntry(pathToAD);
 objADAM.RefreshCache();

wouldn't you want to use pathToAD IF the Length>0?