How to retrieve all groups of a specific user in LDAP? using Novell.Directory.Ldap

Question

I am trying to retrieve all groups assigned to a user in LDAP Apache Directory Studio. I am using Novell.Directory.Ldap library and used .NET Core. I am not sure if I'm doing the correct one but, I have tried one below but it's giving me error on LdapAttribute attribute = userEntry.GetAttribute("memberOf");

{"The given key 'memberOf' was not present in the dictionary."}

. What I am doing wrong? Is there any other solution to achieve to retrieve all groups assigned to a user?

            using (var connection = new LdapConnection() { SecureSocketLayer = false })
            {
                connection.Connect(_ldapSettings.Server, _ldapSettings.Port);
                if (_ldapSettings.UseSSL)
                    connection.StartTls();

                connection.Bind("cn=sample,ou=users,ou=system", password);

                ILdapSearchResults searchResults = connection.Search(
                    "cn=sample,ou=users,ou=system",
                    LdapConnection.ScopeSub,
                    "(objectClass=*)",
                    null,
                    false 
                );

                LdapEntry userEntry = searchResults.Next();
                LdapAttribute attribute = userEntry.GetAttribute("memberOf");

                if (attribute != null)
                {
                    string[] groupDns = attribute.StringValueArray;
                    foreach (string groupDn in groupDns)
                    {
                        Console.WriteLine(groupDn);
                    }
                }

                return true;
            }

Below is an example user assigned to group Administrators.

Answer 1

You need to specify the attributes you want the LDAP server to return:

string[] attributeList = new string[] { "memberOf" };

ILdapSearchResults searchResults = connection.Search(
    "cn=sample,ou=users,ou=system",
    LdapConnection.ScopeSub,
    "(objectClass=*)",
    attributeList,
    false 
);