How to get all the AD groups for a particular user?

Question

I checked this post already. But it doesn\'t answer my question. I want to get all the active directory groups in which a particular user is a member.

I\'ve written

Answer 1

This code works even faster (two 1.5 faster than my previous version):

    public List GetUserGroups(WindowsIdentity identity)
    {
        List groups = new List();

        String userName = identity.Name;
        int pos = userName.IndexOf(@"\");
        if (pos > 0) userName = userName.Substring(pos + 1);

        PrincipalContext domain = new PrincipalContext(ContextType.Domain, "riomc.com");
        UserPrincipal user = UserPrincipal.FindByIdentity(domain, IdentityType.SamAccountName, userName); // NGeodakov

        DirectoryEntry de = new DirectoryEntry("LDAP://RIOMC.com");
        DirectorySearcher search = new DirectorySearcher(de);
        search.Filter = "(&(objectClass=group)(member=" + user.DistinguishedName + "))";
        search.PropertiesToLoad.Add("cn");
        search.PropertiesToLoad.Add("samaccountname");
        search.PropertiesToLoad.Add("memberOf");

        SearchResultCollection results = search.FindAll();
        foreach (SearchResult sr in results)
        {
            GetUserGroupsRecursive(groups, sr, de);
        }

        return groups;
    }

    public void GetUserGroupsRecursive(List groups, SearchResult sr, DirectoryEntry de)
    {
        if (sr == null) return;

        String group = (String)sr.Properties["cn"][0];
        if (String.IsNullOrEmpty(group))
        {
            group = (String)sr.Properties["samaccountname"][0];
        }
        if (!groups.Contains(group))
        {
            groups.Add(group);
        }

        DirectorySearcher search;
        SearchResult sr1;
        String name;
        int equalsIndex, commaIndex;
        foreach (String dn in sr.Properties["memberof"])
        {
            equalsIndex = dn.IndexOf("=", 1);
            if (equalsIndex > 0)
            {
                commaIndex = dn.IndexOf(",", equalsIndex + 1);
                name = dn.Substring(equalsIndex + 1, commaIndex - equalsIndex - 1);

                search = new DirectorySearcher(de);
                search.Filter = "(&(objectClass=group)(|(cn=" + name + ")(samaccountname=" + name + ")))";
                search.PropertiesToLoad.Add("cn");
                search.PropertiesToLoad.Add("samaccountname");
                search.PropertiesToLoad.Add("memberOf");
                sr1 = search.FindOne();
                GetUserGroupsRecursive(groups, sr1, de);
            }
        }
    }