问使用Novell.Directory.Ldap.NETStandard从AD读取所有用户

EN

using Novell.Directory.Ldap;
using Novell.Directory.Ldap.Controls;
using System.Linq;

namespace LdapTestApp
{
    class Program
    {
        static void Main()
        {
            LdapConnection ldapConn = new LdapConnection();
            ldapConn.SecureSocketLayer = true;
            ldapConn.Connect(HOST, PORT);

            try
            {
                var cntRead = 0;
                int? cntTotal = null;
                var curPage = 0;

                ldapConn.Bind(USERNAME, PASSWORD);

                do
                {
                    var constraints = new LdapSearchConstraints();
                    constraints.SetControls(new LdapControl[]
                    {
                        new LdapSortControl(new LdapSortKey("sn"), true),
                        new LdapVirtualListControl("sn=*", 0, 10)
                    });

                    ILdapSearchResults searchResults = ldapConn.Search(
                        "OU=All Users,DC=homecredit,DC=ru",
                        LdapConnection.ScopeSub,
                        "(&(objectCategory=person)(objectClass=user))",
                        null,
                        false,
                        constraints
                    );

                    while (searchResults.HasMore() && ((cntTotal == null) || (cntRead < cntTotal)))
                    {
                        ++cntRead;

                        try
                        {
                            LdapEntry entry = searchResults.Next();
                        }
                        catch (LdapReferralException)
                        {
                            continue;
                        }
                    }

                    ++curPage;
                    cntTotal = GetTotalCount(searchResults as LdapSearchResults);
                } while ((cntTotal != null) && (cntRead < cntTotal));
            }
            finally
            {
                ldapConn.Disconnect();
            }
        }

        private static int? GetTotalCount(LdapSearchResults results)
        {
            if (results.ResponseControls != null)
            {
                var r = (from c in results.ResponseControls
                         let d = c as LdapVirtualListResponse
                         where (d != null)
                         select (LdapVirtualListResponse)c).SingleOrDefault();
                if (r != null)
                {
                    return r.ContentCount;
                }
            }

            return null;
        }
    }
}

"Unavailable Critical Extension"
000020EF: SvcErr: DSID-03140594, problem 5010 (UNAVAIL_EXTENSION), data 0