BLL.Ldap.Authenticate C# (CSharp) Method

        public bool Authenticate(string username, string pwd, string ldapGroup=null)
        {
            if (Settings.LdapEnabled != "1") return false;

            string path = "LDAP://" + Settings.LdapServer + ":" + Settings.LdapPort + "/" + Settings.LdapBaseDN;
            string _filterAttribute = null;

            DirectoryEntry entry = new DirectoryEntry(path,username,pwd);

            if(Settings.LdapAuthType == "Basic")
                entry.AuthenticationType = AuthenticationTypes.None;
            else if (Settings.LdapAuthType == "Secure")
                entry.AuthenticationType = AuthenticationTypes.Secure;
            else if (Settings.LdapAuthType == "SSL")
                entry.AuthenticationType = AuthenticationTypes.SecureSocketsLayer;
            try
            {
                // Bind to the native AdsObject to force authentication.
                Object obj = entry.NativeObject;
                DirectorySearcher search = new DirectorySearcher(entry);
                search.Filter = "(" + Settings.LdapAuthAttribute + "=" + username + ")";
                search.PropertiesToLoad.Add("cn");
                search.PropertiesToLoad.Add("memberOf");

                SearchResult result = search.FindOne();
                if (null == result)
                {
                    return false;
                }

                // Update the new path to the user in the directory
                path = result.Path;
                _filterAttribute = (String)result.Properties["cn"][0];
            }
            catch (Exception ex)
            {
                Logger.Log("Could Not Authenticate User: " + username + " " + ex.Message);
                return false;
            }

            if (ldapGroup != null)
            {
                return GetGroups(_filterAttribute, path,ldapGroup);
            }
            else
                return true;
        }