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Editing: http_01.py
"""A class that performs HTTP-01 challenges for Nginx""" import logging from typing import Any from typing import List from typing import Optional from typing import TYPE_CHECKING from acme import challenges from acme.challenges import KeyAuthorizationChallengeResponse from certbot import errors from certbot.achallenges import KeyAuthorizationAnnotatedChallenge from certbot.compat import os from certbot.plugins import common from certbot_nginx._internal import nginxparser from certbot_nginx._internal.obj import Addr if TYPE_CHECKING: from certbot_nginx._internal.configurator import NginxConfigurator logger = logging.getLogger(__name__) class NginxHttp01(common.ChallengePerformer): """HTTP-01 authenticator for Nginx :ivar configurator: NginxConfigurator object :type configurator: :class:`~nginx.configurator.NginxConfigurator` :ivar list achalls: Annotated class:`~certbot.achallenges.KeyAuthorizationAnnotatedChallenge` challenges :param list indices: Meant to hold indices of challenges in a larger array. NginxHttp01 is capable of solving many challenges at once which causes an indexing issue within NginxConfigurator who must return all responses in order. Imagine NginxConfigurator maintaining state about where all of the challenges, possibly of different types, belong in the response array. This is an optional utility. """ def __init__(self, configurator: "NginxConfigurator") -> None: super().__init__(configurator) self.configurator: "NginxConfigurator" self.challenge_conf = os.path.join( configurator.config.config_dir, "le_http_01_cert_challenge.conf") def perform(self) -> List[KeyAuthorizationChallengeResponse]: """Perform a challenge on Nginx. :returns: list of :class:`acme.challenges.KeyAuthorizationChallengeResponse` :rtype: list """ if not self.achalls: return [] responses = [x.response(x.account_key) for x in self.achalls] # Set up the configuration self._mod_config() # Save reversible changes self.configurator.save("HTTP Challenge", True) return responses def _mod_config(self) -> None: """Modifies Nginx config to include server_names_hash_bucket_size directive and server challenge blocks. :raises .MisconfigurationError: Unable to find a suitable HTTP block in which to include authenticator hosts. """ included = False include_directive = ['\n', 'include', ' ', self.challenge_conf] http_path = self.configurator.parser.http_path bucket_directive = ['\n', 'server_names_hash_bucket_size', ' ', '128'] main = self.configurator.parser.parsed[http_path] # insert include directive for line in main: if line[0] == ['http']: body = line[1] if include_directive not in body: body.insert(0, include_directive) included = True break # insert or update the server_names_hash_bucket_size directive # We have several options here. # 1) Only check nginx.conf # 2) Check included files, assuming they've been included inside http already, # because if they added it outside an http block their config is broken anyway # 3) Add metadata during parsing to note if an include happened inside the http block # # 1 causes bugs; see https://github.com/certbot/certbot/issues/5199 # 3 would require a more extensive rewrite and probably isn't necessary anyway # So this code uses option 2. found_bucket = False for file_contents in self.configurator.parser.parsed.values(): body = file_contents # already inside http in an included file for line in file_contents: if line[0] == ['http']: body = line[1] # enter http because this is nginx.conf break for posn, inner_line in enumerate(body): if inner_line[0] == bucket_directive[1]: if int(inner_line[1]) < int(bucket_directive[3]): body[posn] = bucket_directive found_bucket = True break if found_bucket: break if not found_bucket: for line in main: if line[0] == ['http']: body = line[1] body.insert(0, bucket_directive) break root = self.configurator.parser.config_root if not included: raise errors.MisconfigurationError( 'Certbot could not find a block to include ' 'challenges in %s.' % root) config = [self._make_or_mod_server_block(achall) for achall in self.achalls] config = [x for x in config if x is not None] config = nginxparser.UnspacedList(config) logger.debug("Generated server block:\n%s", str(config)) self.configurator.reverter.register_file_creation( True, self.challenge_conf) with open(self.challenge_conf, "w", encoding="utf-8") as new_conf: nginxparser.dump(config, new_conf) def _default_listen_addresses(self) -> List[Addr]: """Finds addresses for a challenge block to listen on. :returns: list of :class:`certbot_nginx._internal.obj.Addr` to apply :rtype: list """ addresses: List[Addr] = [] default_addr = "%s" % self.configurator.config.http01_port ipv6_addr = "[::]:{0}".format( self.configurator.config.http01_port) port = self.configurator.config.http01_port ipv6, ipv6only = self.configurator.ipv6_info("[::]", str(port)) if ipv6: # If IPv6 is active in Nginx configuration if not ipv6only: # If ipv6only=on is not already present in the config ipv6_addr = ipv6_addr + " ipv6only=on" addresses = [Addr.fromstring(default_addr), Addr.fromstring(ipv6_addr)] logger.debug(("Using default addresses %s and %s for authentication."), default_addr, ipv6_addr) else: addresses = [Addr.fromstring(default_addr)] logger.debug("Using default address %s for authentication.", default_addr) return addresses def _get_validation_path(self, achall: KeyAuthorizationAnnotatedChallenge) -> str: return os.sep + os.path.join(challenges.HTTP01.URI_ROOT_PATH, achall.chall.encode("token")) def _make_server_block(self, achall: KeyAuthorizationAnnotatedChallenge) -> List[Any]: """Creates a server block for a challenge. :param achall: Annotated HTTP-01 challenge :type achall: :class:`certbot.achallenges.KeyAuthorizationAnnotatedChallenge` :returns: server block for the challenge host :rtype: list """ addrs = self._default_listen_addresses() block = [['listen', ' ', addr.to_string(include_default=False)] for addr in addrs] # Ensure we 404 on any other request by setting a root document_root = os.path.join( self.configurator.config.work_dir, "http_01_nonexistent") block.extend([['server_name', ' ', achall.domain], ['root', ' ', document_root], self._location_directive_for_achall(achall) ]) # TODO: do we want to return something else if they otherwise access this block? return [['server'], block] def _location_directive_for_achall(self, achall: KeyAuthorizationAnnotatedChallenge ) -> List[Any]: validation = achall.validation(achall.account_key) validation_path = self._get_validation_path(achall) location_directive = [['location', ' ', '=', ' ', validation_path], [['default_type', ' ', 'text/plain'], ['return', ' ', '200', ' ', validation]]] return location_directive def _make_or_mod_server_block(self, achall: KeyAuthorizationAnnotatedChallenge ) -> Optional[List[Any]]: """Modifies server blocks to respond to a challenge. Returns a new HTTP server block to add to the configuration if an existing one can't be found. :param achall: Annotated HTTP-01 challenge :type achall: :class:`certbot.achallenges.KeyAuthorizationAnnotatedChallenge` :returns: new server block to be added, if any :rtype: list """ http_vhosts, https_vhosts = self.configurator.choose_auth_vhosts(achall.domain) new_vhost: Optional[List[Any]] = None if not http_vhosts: # Couldn't find either a matching name+port server block # or a port+default_server block, so create a dummy block new_vhost = self._make_server_block(achall) # Modify any existing server blocks for vhost in set(http_vhosts + https_vhosts): location_directive = [self._location_directive_for_achall(achall)] self.configurator.parser.add_server_directives(vhost, location_directive) rewrite_directive = [['rewrite', ' ', '^(/.well-known/acme-challenge/.*)', ' ', '$1', ' ', 'break']] self.configurator.parser.add_server_directives( vhost, rewrite_directive, insert_at_top=True) return new_vhost
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