fetch pgp keys from horde_prefs

hooks.php

    public function  pgp_key($address, $keyid)
    {
      $db = $GLOBALS['injector']->getInstance('Horde_Db_Adapter');
      $query = "SELECT pref_value FROM horde_prefs WHERE pref_name = 'pgp_public_key' AND pref_value <> '' AND pref_uid = ?";
      try {
        $result =  $db->selectOne($query,array($address));
        $columns = $db->columns('horde_prefs');
        if (!empty($result)) {
          $key = $columns['pref_value']->binaryToString($result['pref_value']);
          return $key;
        } else {
          return;
        }
      } catch (Imp_Exception $e) {
        return;
      }
    }