class Net::LDAP::AuthAdapter::Simple

def bind(auth)
  user, psw = if auth[:method] == :simple
                [auth[:username] || auth[:dn], auth[:password]]
              else
                ["", ""]
              end
  raise Net::LDAP::BindingInformationInvalidError, "Invalid binding information" unless user && psw
  message_id = @connection.next_msgid
  request    = [
    Net::LDAP::Connection::LdapVersion.to_ber, user.to_ber,
    psw.to_ber_contextspecific(0)
  ].to_ber_appsequence(Net::LDAP::PDU::BindRequest)
  @connection.send(:write, request, nil, message_id)
  pdu = @connection.queued_read(message_id)
  if !pdu || pdu.app_tag != Net::LDAP::PDU::BindResult
    raise Net::LDAP::NoBindResultError, "no bind result"
  end
  pdu
end