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vã.ÜjbÑ¿Ê„_mÏÀÈ .´    #"""Common code for DNS Authenticator Plugins."""

import abc
import logging
from time import sleep

import configobj
import zope.interface

from acme import challenges
from certbot import errors
from certbot import interfaces
from certbot.compat import filesystem
from certbot.compat import os
from certbot.display import ops
from certbot.display import util as display_util
from certbot.plugins import common

logger = logging.getLogger(__name__)


@zope.interface.implementer(interfaces.IAuthenticator)
@zope.interface.provider(interfaces.IPluginFactory)
class DNSAuthenticator(common.Plugin):
    """Base class for DNS  Authenticators"""

    def __init__(self, config, name):
        super(DNSAuthenticator, self).__init__(config, name)

        self._attempt_cleanup = False

    @classmethod
    def add_parser_arguments(cls, add, default_propagation_seconds=10):  # pylint: disable=arguments-differ
        add('propagation-seconds',
            default=default_propagation_seconds,
            type=int,
            help='The number of seconds to wait for DNS to propagate before asking the ACME server '
                 'to verify the DNS record.')

    def get_chall_pref(self, unused_domain):  # pylint: disable=missing-function-docstring
        return [challenges.DNS01]

    def prepare(self): # pylint: disable=missing-function-docstring
        pass

    def perform(self, achalls): # pylint: disable=missing-function-docstring
        self._setup_credentials()

        self._attempt_cleanup = True

        responses = []
        for achall in achalls:
            domain = achall.domain
            validation_domain_name = achall.validation_domain_name(domain)
            validation = achall.validation(achall.account_key)

            self._perform(domain, validation_domain_name, validation)
            responses.append(achall.response(achall.account_key))

        # DNS updates take time to propagate and checking to see if the update has occurred is not
        # reliable (the machine this code is running on might be able to see an update before
        # the ACME server). So: we sleep for a short amount of time we believe to be long enough.
        logger.info("Waiting %d seconds for DNS changes to propagate",
                    self.conf('propagation-seconds'))
        sleep(self.conf('propagation-seconds'))

        return responses

    def cleanup(self, achalls):  # pylint: disable=missing-function-docstring
        if self._attempt_cleanup:
            for achall in achalls:
                domain = achall.domain
                validation_domain_name = achall.validation_domain_name(domain)
                validation = achall.validation(achall.account_key)

                self._cleanup(domain, validation_domain_name, validation)

    @abc.abstractmethod
    def _setup_credentials(self):  # pragma: no cover
        """
        Establish credentials, prompting if necessary.
        """
        raise NotImplementedError()

    @abc.abstractmethod
    def _perform(self, domain, validation_name, validation):  # pragma: no cover
        """
        Performs a dns-01 challenge by creating a DNS TXT record.

        :param str domain: The domain being validated.
        :param str validation_domain_name: The validation record domain name.
        :param str validation: The validation record content.
        :raises errors.PluginError: If the challenge cannot be performed
        """
        raise NotImplementedError()

    @abc.abstractmethod
    def _cleanup(self, domain, validation_name, validation):  # pragma: no cover
        """
        Deletes the DNS TXT record which would have been created by `_perform_achall`.

        Fails gracefully if no such record exists.

        :param str domain: The domain being validated.
        :param str validation_domain_name: The validation record domain name.
        :param str validation: The validation record content.
        """
        raise NotImplementedError()

    def _configure(self, key, label):