def check_ciphers(fw, service):
    """
    Check if ciphers are already set and if so add them to a list

    Parameters
    ----------
    fw : Firewall
        A PanDevice for firewall
    service : list
        A list of strings containing the SSH services

    Returns
    -------
    set_ciphers_list : list
        A list of strings containing the ciphers already set on the firewall
    """
    print('\nChecking {} ciphers...\n'.format(service))

    base_xpath = ("/config/devices/entry[@name='localhost.localdomain']"
                  "/deviceconfig/system/ssh/ciphers/{}".format(service))
    results = fw.xapi.get(xpath=base_xpath)

    xml_list = results.findall('./result/{}/'.format(service))

    set_ciphers_list = []

    for item in xml_list:
        set_ciphers_list.append(item.tag)

    return set_ciphers_list