C# - GroupPrincipal.GetMembers(true) - which group?

Question

So I'm trying to get something going with enumerating AD group membership recursively. At the moment I have...

PrincipalContext ctx = new PrincipalContext(ContextType.Domain, "mine.domain.com");
GroupPrincipal grp = GroupPrincipal.FindByIdentity(ctx, IdentityType.Name, "myADGroup");
if (grp != null)
{
    foreach (Principal p in grp.GetMembers(true))
    {
        Console.WriteLine(p.Name);
    }
}

This all works great, of course. It lists every user who is a member of the group and all the users who are members of groups nested within, however many nesting levels deep that may be. Which is great.

What I really need is to know what group in this little nesting the user came from.

GRP-MainProject
   -- GRP-Producers
   -- GRP-Artists
     -- UserA

Running my current query against GRP-MainProject will return UserA - how should I go about returning the user and the fact that it was GRP-Artists which he inherited membership of GRP-MainProject from?

UserA is a member of about 40 groups or so, in case that matters. Edit - worth mentioning the user could have membership of the group from multiple nested groups.

Any thoughts would be appreciated.

Answer 1

Try something like this maybe:

Declare Static List of Group Objects (simple class of GroupPrincipal, integer level, and parent GroupPrincipal)

public class SomeDirTraverser
{
    private static List<GroupObj> _groups = new List<GroupObj>();

    public List<string> GetMembershipWithPath(string groupname)
    {
        List<string> retVal = new List<string>();

        PrincipalContext ctx = new PrincipalContext(ContextType.Domain);
        GroupPrincipal grp = GroupPrincipal.FindByIdentity(ctx, IdentityType.Name, groupname);
        if (grp != null)
        {
            BuildHList(grp, 0, null);
            foreach (UserPrincipal usr in grp.GetMembers(true))
                retVal.Add(GetMbrPath(usr));
        }

        return retVal;
    }

    private void BuildHList(GroupPrincipal node, int level, GroupPrincipal parent)
    {
        PrincipalSearchResult<Principal> rslts = node.GetMembers();
        _groups.Add(new GroupObj() { Group = node, Level = level, Parent = parent });
        foreach (GroupPrincipal grp in rslts.Where(g => g is GroupPrincipal))
            BuildHList(grp, level + 1, node);
    }

    private string GetMbrPath(UserPrincipal usr)
    {
        Stack<string> output = new Stack<string>();
        StringBuilder retVal = new StringBuilder();
        GroupObj fg = null, tg = null;
        output.Push(usr.Name);
        foreach (GroupObj go in _groups)
        {
            if (usr.IsMemberOf(go.Group))
            {
                output.Push(go.Group.Name);
                fg = go;
                while (fg.Parent != null)
                {
                    output.Push(fg.Parent.Name);
                    tg = (from g in _groups where g.Group == fg.Parent select g).FirstOrDefault();
                    fg = tg;
                }
                break;
            }
        }
        while (output.Count > 1)
            retVal.AppendFormat("{0} ->", output.Pop());
        retVal.Append(output.Pop());

        return retVal.ToString();
    }
}

public class GroupObj
{
    public GroupPrincipal Group { get; set; }
    public int Level { get; set; }
    public GroupPrincipal Parent { get; set; }
}

This one looks like it should give you what you want.