certbot/letsencrypt/interfaces.py

"""Let's Encrypt client interfaces."""
import abc
import zope.interface

# pylint: disable=no-self-argument,no-method-argument,no-init,inherit-non-class
# pylint: disable=too-few-public-methods


class AccountStorage(object):
    """Accounts storage interface."""

    __metaclass__ = abc.ABCMeta

    @abc.abstractmethod
    def find_all(self):  # pragma: no cover
        """Find all accounts.

        :returns: All found accounts.
        :rtype: list

        """
        raise NotImplementedError()

    @abc.abstractmethod
    def load(self, account_id):  # pragma: no cover
        """Load an account by its id.

        :raises .AccountNotFound: if account could not be found
        :raises .AccountStorageError: if account could not be loaded

        """
        raise NotImplementedError()

    @abc.abstractmethod
    def save(self, account):  # pragma: no cover
        """Save account.

        :raises .AccountStorageError: if account could not be saved

        """
        raise NotImplementedError()


class IPluginFactory(zope.interface.Interface):
    """IPlugin factory.

    Objects providing this interface will be called without satisfying
    any entry point "extras" (extra dependencies) you might have defined
    for your plugin, e.g (excerpt from ``setup.py`` script)::

      setup(
          ...
          entry_points={
              'letsencrypt.plugins': [
                  'name=example_project.plugin[plugin_deps]',
              ],
          },
          extras_require={
              'plugin_deps': ['dep1', 'dep2'],
          }
      )

    Therefore, make sure such objects are importable and usable without
    extras. This is necessary, because CLI does the following operations
    (in order):

      - loads an entry point,
      - calls `inject_parser_options`,
      - requires an entry point,
      - creates plugin instance (`__call__`).

    """

    description = zope.interface.Attribute("Short plugin description")

    def __call__(config, name):
        """Create new `IPlugin`.

        :param IConfig config: Configuration.
        :param str name: Unique plugin name.

        """

    def inject_parser_options(parser, name):
        """Inject argument parser options (flags).

        1. Be nice and prepend all options and destinations with
        `~.common.option_namespace` and `~common.dest_namespace`.

        2. Inject options (flags) only. Positional arguments are not
        allowed, as this would break the CLI.

        :param ArgumentParser parser: (Almost) top-level CLI parser.
        :param str name: Unique plugin name.

        """


class IPlugin(zope.interface.Interface):
    """Let's Encrypt plugin."""

    def prepare():
        """Prepare the plugin.

        Finish up any additional initialization.

        :raises .PluginError:
            when full initialization cannot be completed.
        :raises .MisconfigurationError:
            when full initialization cannot be completed. Plugin will
            be displayed on a list of available plugins.
        :raises .NoInstallationError:
            when the necessary programs/files cannot be located. Plugin
            will NOT be displayed on a list of available plugins.
        :raises .NotSupportedError:
            when the installation is recognized, but the version is not
            currently supported.

        """

    def more_info():
        """Human-readable string to help the user.

        Should describe the steps taken and any relevant info to help the user
        decide which plugin to use.

        :rtype str:

        """


class IAuthenticator(IPlugin):
    """Generic Let's Encrypt Authenticator.

    Class represents all possible tools processes that have the
    ability to perform challenges and attain a certificate.

    """

    def get_chall_pref(domain):
        """Return list of challenge preferences.

        :param str domain: Domain for which challenge preferences are sought.

        :returns: List of challenge types (subclasses of
            :class:`acme.challenges.Challenge`) with the most
            preferred challenges first. If a type is not specified, it means the
            Authenticator cannot perform the challenge.
        :rtype: list

        """

    def perform(achalls):
        """Perform the given challenge.

        :param list achalls: Non-empty (guaranteed) list of
            :class:`~letsencrypt.achallenges.AnnotatedChallenge`
            instances, such that it contains types found within
            :func:`get_chall_pref` only.

        :returns: List of ACME
            :class:`~acme.challenges.ChallengeResponse` instances
            or if the :class:`~acme.challenges.Challenge` cannot
            be fulfilled then:

            ``None``
              Authenticator can perform challenge, but not at this time.
            ``False``
              Authenticator will never be able to perform (error).

        :rtype: :class:`list` of
            :class:`acme.challenges.ChallengeResponse`,
            where responses are required to be returned in
            the same order as corresponding input challenges

        :raises .PluginError: If challenges cannot be performed

        """

    def cleanup(achalls):
        """Revert changes and shutdown after challenges complete.

        :param list achalls: Non-empty (guaranteed) list of
            :class:`~letsencrypt.achallenges.AnnotatedChallenge`
            instances, a subset of those previously passed to :func:`perform`.

        :raises PluginError: if original configuration cannot be restored

        """


class IConfig(zope.interface.Interface):
    """Let's Encrypt user-supplied configuration.

    .. warning:: The values stored in the configuration have not been
        filtered, stripped or sanitized.

    """
    server = zope.interface.Attribute("ACME Directory Resource URI.")
    email = zope.interface.Attribute(
        "Email used for registration and recovery contact.")
    rsa_key_size = zope.interface.Attribute("Size of the RSA key.")

    config_dir = zope.interface.Attribute("Configuration directory.")
    work_dir = zope.interface.Attribute("Working directory.")

    accounts_dir = zope.interface.Attribute(
        "Directory where all account information is stored.")
    backup_dir = zope.interface.Attribute("Configuration backups directory.")
    csr_dir = zope.interface.Attribute(
        "Directory where newly generated Certificate Signing Requests "
        "(CSRs) are saved.")
    in_progress_dir = zope.interface.Attribute(
        "Directory used before a permanent checkpoint is finalized.")
    key_dir = zope.interface.Attribute("Keys storage.")
    temp_checkpoint_dir = zope.interface.Attribute(
        "Temporary checkpoint directory.")

    renewer_config_file = zope.interface.Attribute(
        "Location of renewal configuration file.")

    no_verify_ssl = zope.interface.Attribute(
        "Disable SSL certificate verification.")
    tls_sni_01_port = zope.interface.Attribute(
        "Port number to perform tls-sni-01 challenge. "
        "Boulder in testing mode defaults to 5001.")

    http01_port = zope.interface.Attribute(
        "Port used in the SimpleHttp challenge.")


class IInstaller(IPlugin):
    """Generic Let's Encrypt Installer Interface.

    Represents any server that an X509 certificate can be placed.

    """

    def get_all_names():
        """Returns all names that may be authenticated.

        :rtype: `list` of `str`

        """

    def deploy_cert(domain, cert_path, key_path, chain_path, fullchain_path):
        """Deploy certificate.

        :param str domain: domain to deploy certificate file
        :param str cert_path: absolute path to the certificate file
        :param str key_path: absolute path to the private key file
        :param str chain_path: absolute path to the certificate chain file
        :param str fullchain_path: absolute path to the certificate fullchain
            file (cert plus chain)

        :raises .PluginError: when cert cannot be deployed

        """

    def enhance(domain, enhancement, options=None):
        """Perform a configuration enhancement.

        :param str domain: domain for which to provide enhancement
        :param str enhancement: An enhancement as defined in
            :const:`~letsencrypt.constants.ENHANCEMENTS`
        :param options: Flexible options parameter for enhancement.
            Check documentation of
            :const:`~letsencrypt.constants.ENHANCEMENTS`
            for expected options for each enhancement.

        :raises .PluginError: If Enhancement is not supported, or if
            an error occurs during the enhancement.

        """

    def supported_enhancements():
        """Returns a list of supported enhancements.

        :returns: supported enhancements which should be a subset of
            :const:`~letsencrypt.constants.ENHANCEMENTS`
        :rtype: :class:`list` of :class:`str`

        """

    def get_all_certs_keys():
        """Retrieve all certs and keys set in configuration.

        :returns: tuples with form `[(cert, key, path)]`, where:

            - `cert` - str path to certificate file
            - `key` - str path to associated key file
            - `path` - file path to configuration file

        :rtype: list

        """

    def save(title=None, temporary=False):
        """Saves all changes to the configuration files.

        Both title and temporary are needed because a save may be
        intended to be permanent, but the save is not ready to be a full
        checkpoint. If an exception is raised, it is assumed a new
        checkpoint was not created.

        :param str title: The title of the save. If a title is given, the
            configuration will be saved as a new checkpoint and put in a
            timestamped directory. `title` has no effect if temporary is true.

        :param bool temporary: Indicates whether the changes made will
            be quickly reversed in the future (challenges)

        :raises .PluginError: when save is unsuccessful

        """

    def rollback_checkpoints(rollback=1):
        """Revert `rollback` number of configuration checkpoints.

        :raises .PluginError: when configuration cannot be fully reverted

        """

    def recovery_routine():
        """Revert configuration to most recent finalized checkpoint.

        Remove all changes (temporary and permanent) that have not been
        finalized. This is useful to protect against crashes and other
        execution interruptions.

        :raises .errors.PluginError: If unable to recover the configuration

        """

    def view_config_changes():
        """Display all of the LE config changes.

        :raises .PluginError: when config changes cannot be parsed

        """

    def config_test():
        """Make sure the configuration is valid.

        :raises .MisconfigurationError: when the config is not in a usable state

        """

    def restart():
        """Restart or refresh the server content.

        :raises .PluginError: when server cannot be restarted

        """


class IDisplay(zope.interface.Interface):
    """Generic display."""

    def notification(message, height, pause):
        """Displays a string message

        :param str message: Message to display
        :param int height: Height of dialog box if applicable
        :param bool pause: Whether or not the application should pause for
            confirmation (if available)

        """

    def menu(message, choices, ok_label="OK",      # pylint: disable=too-many-arguments
             cancel_label="Cancel", help_label="", default=None, cli_flag=None):
        """Displays a generic menu.

        :param str message: message to display

        :param choices: choices
        :type choices: :class:`list` of :func:`tuple` or :class:`str`

        :param str ok_label: label for OK button
        :param str cancel_label: label for Cancel button
        :param str help_label: label for Help button
        :param int default: default (non-interactive) choice from the menu
        :param str cli_flag: to automate choice from the menu, eg "--keep"

        :returns: tuple of (`code`, `index`) where
            `code` - str display exit code
            `index` - int index of the user's selection

        :raises errors.MissingCommandlineFlag: if called in non-interactive
            mode without a default set

        """

    def input(message, default=None, cli_args=None):
        """Accept input from the user.

        :param str message: message to display to the user

        :returns: tuple of (`code`, `input`) where
            `code` - str display exit code
            `input` - str of the user's input
        :rtype: tuple

        :raises errors.MissingCommandlineFlag: if called in non-interactive
            mode without a default set

        """

    def yesno(message, yes_label="Yes", no_label="No", default=None,
              cli_args=None):
        """Query the user with a yes/no question.

        Yes and No label must begin with different letters.

        :param str message: question for the user
        :param str default: default (non-interactive) choice from the menu
        :param str cli_flag: to automate choice from the menu, eg "--redirect / --no-redirect"

        :returns: True for "Yes", False for "No"
        :rtype: bool

        :raises errors.MissingCommandlineFlag: if called in non-interactive
            mode without a default set

        """

    def checklist(message, tags, default_state, default=None, cli_args=None):
        """Allow for multiple selections from a menu.

        :param str message: message to display to the user
        :param list tags: where each is of type :class:`str` len(tags) > 0
        :param bool default_status: If True, items are in a selected state by default.
        :param str default: default (non-interactive) state of the checklist
        :param str cli_flag: to automate choice from the menu, eg "--domains"

        :returns: tuple of the form (code, list_tags) where
            `code` - int display exit code
            `list_tags` - list of str tags selected by the user
        :rtype: tuple

        :raises errors.MissingCommandlineFlag: if called in non-interactive
            mode without a default set

        """

    def directory_select(self, message, default=None, cli_flag=None):
        """Display a directory selection screen.

        :param str message: prompt to give the user
        :param default: the default value to return, if one exists, when
            using the NoninteractiveDisplay
        :param str cli_flag: option used to set this value with the CLI,
            if one exists, to be included in error messages given by
            NoninteractiveDisplay

        :returns: tuple of the form (`code`, `string`) where
            `code` - int display exit code
            `string` - input entered by the user

        """


class IValidator(zope.interface.Interface):
    """Configuration validator."""

    def certificate(cert, name, alt_host=None, port=443):
        """Verifies the certificate presented at name is cert

        :param OpenSSL.crypto.X509 cert: Expected certificate
        :param str name: Server's domain name
        :param bytes alt_host: Host to connect to instead of the IP
            address of host
        :param int port: Port to connect to

        :returns: True if the certificate was verified successfully
        :rtype: bool

        """

    def redirect(name, port=80, headers=None):
        """Verify redirect to HTTPS

        :param str name: Server's domain name
        :param int port: Port to connect to
        :param dict headers: HTTP headers to include in request

        :returns: True if redirect is successfully enabled
        :rtype: bool

        """

    def hsts(name):
        """Verify HSTS header is enabled

        :param str name: Server's domain name

        :returns: True if HSTS header is successfully enabled
        :rtype: bool

        """

    def ocsp_stapling(name):
        """Verify ocsp stapling for domain

        :param str name: Server's domain name

        :returns: True if ocsp stapling is successfully enabled
        :rtype: bool

        """


class IReporter(zope.interface.Interface):
    """Interface to collect and display information to the user."""

    HIGH_PRIORITY = zope.interface.Attribute(
        "Used to denote high priority messages")
    MEDIUM_PRIORITY = zope.interface.Attribute(
        "Used to denote medium priority messages")
    LOW_PRIORITY = zope.interface.Attribute(
        "Used to denote low priority messages")

    def add_message(self, msg, priority, on_crash=True):
        """Adds msg to the list of messages to be printed.

        :param str msg: Message to be displayed to the user.

        :param int priority: One of HIGH_PRIORITY, MEDIUM_PRIORITY, or
            LOW_PRIORITY.

        :param bool on_crash: Whether or not the message should be printed if
            the program exits abnormally.

        """

    def print_messages(self):
        """Prints messages to the user and clears the message queue."""