Source code for certbot.plugins.standalone

"""Standalone Authenticator."""
import argparse
import collections
import logging
import socket

import OpenSSL
import six
import zope.interface

from acme import challenges
from acme import standalone as acme_standalone

from certbot import errors
from certbot import interfaces

from certbot.plugins import common

logger = logging.getLogger(__name__)

[docs]class ServerManager(object): """Standalone servers manager. Manager for `ACMEServer` and `ACMETLSServer` instances. `certs` and `http_01_resources` correspond to `acme.crypto_util.SSLSocket.certs` and `acme.crypto_util.SSLSocket.http_01_resources` respectively. All created servers share the same certificates and resources, so if you're running both TLS and non-TLS instances, HTTP01 handlers will serve the same URLs! """ def __init__(self, certs, http_01_resources): self._instances = {} self.certs = certs self.http_01_resources = http_01_resources
[docs] def run(self, port, challenge_type, listenaddr=""): """Run ACME server on specified ``port``. This method is idempotent, i.e. all calls with the same pair of ``(port, challenge_type)`` will reuse the same server. :param int port: Port to run the server on. :param challenge_type: Subclass of `acme.challenges.Challenge`, either `acme.challenge.HTTP01` or `acme.challenges.TLSSNI01`. :param str listenaddr: (optional) The address to listen on. Defaults to all addrs. :returns: DualNetworkedServers instance. :rtype: ACMEServerMixin """ assert challenge_type in (challenges.TLSSNI01, challenges.HTTP01) if port in self._instances: return self._instances[port] address = (listenaddr, port) try: if challenge_type is challenges.TLSSNI01: servers = acme_standalone.TLSSNI01DualNetworkedServers(address, self.certs) else: # challenges.HTTP01 servers = acme_standalone.HTTP01DualNetworkedServers( address, self.http_01_resources) except socket.error as error: raise errors.StandaloneBindError(error, port) servers.serve_forever() # if port == 0, then random free port on OS is taken # pylint: disable=no-member # both servers, if they exist, have the same port real_port = servers.getsocknames()[0][1] self._instances[real_port] = servers return servers
[docs] def stop(self, port): """Stop ACME server running on the specified ``port``. :param int port: """ instance = self._instances[port] for sockname in instance.getsocknames(): logger.debug("Stopping server at %s:%d...", *sockname[:2]) # Not calling server_close causes problems when renewing multiple # certs with `certbot renew` using TLSSNI01 and PyOpenSSL 0.13 instance.shutdown_and_server_close() del self._instances[port]
[docs] def running(self): """Return all running instances. Once the server is stopped using `stop`, it will not be returned. :returns: Mapping from ``port`` to ``servers``. :rtype: tuple """ return self._instances.copy()
SUPPORTED_CHALLENGES = [challenges.TLSSNI01, challenges.HTTP01]
[docs]class SupportedChallengesAction(argparse.Action): """Action class for parsing standalone_supported_challenges.""" def __call__(self, parser, namespace, values, option_string=None): logger.warning( "The standalone specific supported challenges flag is " "deprecated. Please use the --preferred-challenges flag " "instead.") converted_values = self._convert_and_validate(values) namespace.standalone_supported_challenges = converted_values
[docs] def _convert_and_validate(self, data): """Validate the value of supported challenges provided by the user. References to "dvsni" are automatically converted to "tls-sni-01". :param str data: comma delimited list of challenge types :returns: validated and converted list of challenge types :rtype: str """ challs = data.split(",") # tls-sni-01 was dvsni during private beta if "dvsni" in challs: "Updating legacy standalone_supported_challenges value") challs = [challenges.TLSSNI01.typ if chall == "dvsni" else chall for chall in challs] data = ",".join(challs) unrecognized = [name for name in challs if name not in challenges.Challenge.TYPES] # argparse.ArgumentErrors raised out of argparse.Action objects # are caught by argparse which prints usage information and the # error that occurred before calling sys.exit. if unrecognized: raise argparse.ArgumentError( self, "Unrecognized challenges: {0}".format(", ".join(unrecognized))) choices = set(chall.typ for chall in SUPPORTED_CHALLENGES) if not set(challs).issubset(choices): raise argparse.ArgumentError( self, "Plugin does not support the following (valid) " "challenges: {0}".format(", ".join(set(challs) - choices))) return data
@zope.interface.implementer(interfaces.IAuthenticator) @zope.interface.provider(interfaces.IPluginFactory)
[docs]class Authenticator(common.Plugin): """Standalone Authenticator. This authenticator creates its own ephemeral TCP listener on the necessary port in order to respond to incoming tls-sni-01 and http-01 challenges from the certificate authority. Therefore, it does not rely on any existing server program. """ description = "Spin up a temporary webserver" def __init__(self, *args, **kwargs): super(Authenticator, self).__init__(*args, **kwargs) # one self-signed key for all tls-sni-01 certificates self.key = OpenSSL.crypto.PKey() self.key.generate_key(OpenSSL.crypto.TYPE_RSA, 2048) self.served = collections.defaultdict(set) # Stuff below is shared across threads (i.e. servers read # values, main thread writes). Due to the nature of CPython's # GIL, the operations are safe, c.f. # self.certs = {} self.http_01_resources = set() self.servers = ServerManager(self.certs, self.http_01_resources) @classmethod def add_parser_arguments(cls, add): add("supported-challenges", help=argparse.SUPPRESS, action=SupportedChallengesAction, default=",".join(chall.typ for chall in SUPPORTED_CHALLENGES)) @property def supported_challenges(self): """Challenges supported by this plugin.""" return [challenges.Challenge.TYPES[name] for name in self.conf("supported-challenges").split(",")] def more_info(self): # pylint: disable=missing-docstring return("This authenticator creates its own ephemeral TCP listener " "on the necessary port in order to respond to incoming " "tls-sni-01 and http-01 challenges from the certificate " "authority. Therefore, it does not rely on any existing " "server program.") def prepare(self): # pylint: disable=missing-docstring pass def get_chall_pref(self, domain): # pylint: disable=unused-argument,missing-docstring return self.supported_challenges def perform(self, achalls): # pylint: disable=missing-docstring return [self._try_perform_single(achall) for achall in achalls] def _try_perform_single(self, achall): while True: try: return self._perform_single(achall) except errors.StandaloneBindError as error: _handle_perform_error(error) def _perform_single(self, achall): if isinstance(achall.chall, challenges.HTTP01): servers, response = self._perform_http_01(achall) else: # tls-sni-01 servers, response = self._perform_tls_sni_01(achall) self.served[servers].add(achall) return response def _perform_http_01(self, achall): port = self.config.http01_port addr = self.config.http01_address servers =, challenges.HTTP01, listenaddr=addr) response, validation = achall.response_and_validation() resource = acme_standalone.HTTP01RequestHandler.HTTP01Resource( chall=achall.chall, response=response, validation=validation) self.http_01_resources.add(resource) return servers, response def _perform_tls_sni_01(self, achall): port = self.config.tls_sni_01_port addr = self.config.tls_sni_01_address servers =, challenges.TLSSNI01, listenaddr=addr) response, (cert, _) = achall.response_and_validation(cert_key=self.key) self.certs[response.z_domain] = (self.key, cert) return servers, response def cleanup(self, achalls): # pylint: disable=missing-docstring # reduce self.served and close servers if no challenges are served for unused_servers, server_achalls in self.served.items(): for achall in achalls: if achall in server_achalls: server_achalls.remove(achall) for port, servers in six.iteritems(self.servers.running()): if not self.served[servers]: self.servers.stop(port)
def _handle_perform_error(error): if error.socket_error.errno == socket.errno.EACCES: raise errors.PluginError( "Could not bind TCP port {0} because you don't have " "the appropriate permissions (for example, you " "aren't running this program as " "root).".format(error.port)) elif error.socket_error.errno == socket.errno.EADDRINUSE: display = zope.component.getUtility(interfaces.IDisplay) msg = ( "Could not bind TCP port {0} because it is already in " "use by another process on this system (such as a web " "server). Please stop the program in question and " "then try again.".format(error.port)) should_retry = display.yesno(msg, "Retry", "Cancel", default=False) if not should_retry: raise errors.PluginError(msg) else: raise