#!/usr/bin/env python # -*- coding: utf-8 -*- # Automated Certificate Manager using ACME # Copyright (c) Markus Hauschild & David Klaftenegger, 2016. # Copyright (c) Rudolf Mayerhofer, 2019. # available under the ISC license, see LICENSE import grp import hashlib import importlib import os import pwd import shutil import stat import subprocess import tempfile import acme import tools ACME_DIR = "/etc/acme" ACME_CONF = os.path.join(ACME_DIR, "acme.conf") ACME_CONFD = os.path.join(ACME_DIR, "domains.d") ACME_DEFAULT_SERVER_KEY = os.path.join(ACME_DIR, "server.key") ACME_DEFAULT_ACCOUNT_KEY = os.path.join(ACME_DIR, "account.key") # @brief check whether existing target file is still valid or source crt has been updated # @param target string containing the path to the target file # @param crt_file string containing the path to the certificate file # @return True if target file is at least as new as the certificate, False otherwise def target_is_current(target, crt_file): if not os.path.isfile(target): return False target_date = os.path.getmtime(target) crt_date = os.path.getmtime(crt_file) return target_date >= crt_date # @brief create a challenge handler for the given configuration # @param config the domain's configuration options def create_challenge_handler(config): if "mode" in config: mode = config["mode"] else: mode = "standalone" handler_module = importlib.import_module("modes.{0}".format(mode)) handler_class = getattr(handler_module, "ChallengeHandler") return handler_class(config) # @brief fetch new certificate from letsencrypt # @param domains string containing all domain names # @param globalconfig the global configuration options # @param handlerconfigs the domain's handler configuration options def cert_get(domains, globalconfig, handlerconfigs): print("Getting certificate for '%s'." % domains) key_file = globalconfig['server_key'] if not os.path.isfile(key_file): print("Server key not found at '{0}'. Creating RSA key.".format(key_file)) tools.new_rsa_key(key_file) acc_file = globalconfig['account_key'] if not os.path.isfile(acc_file): print("Account key not found at '{0}'. Creating RSA key.".format(acc_file)) tools.new_rsa_key(acc_file) filename = hashlib.md5(domains).hexdigest() _, csr_file = tempfile.mkstemp(".csr", "%s." % filename) _, crt_file = tempfile.mkstemp(".crt", "%s." % filename) # find challenge handlers for this certificate challenge_handlers = dict() domainlist = domains.split(' ') for domain in domainlist: # Use global config as base handler config cfg = globalconfig.deepcopy() # Determine generic domain handler config values genericfgs = [x for x in handlerconfigs if 'domain' not in x] if len(genericfgs) > 0: cfg = cfg.update(genericfgs[0]) # Update handler config with more specific values specificcfgs = [x for x in handlerconfigs if ('domain' in x and x['domain'] == domain)] if len(specificcfgs) > 0: cfg = cfg.update(specificcfgs[0]) # Create the challenge handler challenge_handlers[domain] = create_challenge_handler(cfg) try: key = tools.read_key(key_file) cr = tools.new_cert_request(domainlist, key) print("Reading account key...") acc_key = tools.read_key(acc_file) acme.register_account(acc_key, config['authority']) crt = acme.get_crt_from_csr(acc_key, cr, domainlist, challenge_handlers, config['authority']) with open(crt_file, "w") as crt_fd: crt_fd.write(tools.convert_cert_to_pem(crt)) # if resulting certificate is valid: store in final location if tools.is_cert_valid(crt_file, 60): crt_final = os.path.join(ACME_DIR, (hashlib.md5(domains).hexdigest() + ".crt")) shutil.copy2(crt_file, crt_final) os.chmod(crt_final, stat.S_IREAD) finally: os.remove(csr_file) os.remove(crt_file) # @brief put new certificate in place # @param settings the domain's configuration options # @return the action to be executed after the certificate update def cert_put(settings): # TODO error handling ca_file = settings.get("cafile", "") crt_user = settings['user'] crt_group = settings['group'] crt_perm = settings['perm'] crt_path = settings['path'] crt_format = settings['format'].split(",") crt_format = [str.strip(x) for x in crt_format] crt_action = settings['action'] key_file = settings['server_key'] crt_final = os.path.join(ACME_DIR, (hashlib.md5(domains).hexdigest() + ".crt")) with open(crt_path, "w+") as crt_fd: for fmt in crt_format: if fmt == "crt": src_fd = open(crt_final, "r") crt_fd.write(src_fd.read()) src_fd.close() if fmt == "key": src_fd = open(key_file, "r") crt_fd.write(src_fd.read()) src_fd.close() if fmt == "ca": if not os.path.isfile(ca_file): raise FileNotFoundError("The CA certificate file (%s) is missing!" % ca_file) src_fd = open(ca_file, "r") crt_fd.write(src_fd.read()) src_fd.close() else: # TODO error handling pass # set owner and permissions uid = pwd.getpwnam(crt_user).pw_uid gid = grp.getgrnam(crt_group).gr_gid try: os.chown(crt_path, uid, gid) except OSError: print('Warning: Could not set certificate file ownership!') try: os.chmod(crt_path, int(crt_perm, 8)) except OSError: print('Warning: Could not set certificate file permissions!') return crt_action # @brief augment configuration with defaults # @param domainconfig the domain configuration # @param defaults the default configuration # @return the augmented configuration def complete_config(domainconfig, globalconfig): defaults = globalconfig['defaults'] domainconfig['server_key'] = globalconfig['server_key'] for name, value in defaults.items(): if name not in domainconfig: domainconfig[name] = value if 'action' not in domainconfig: domainconfig['action'] = None return domainconfig if __name__ == "__main__": config = dict() # load global configuration if os.path.isfile(ACME_CONF): with open(ACME_CONF) as config_fd: try: import json config = json.load(config_fd) except json.JSONDecodeError: import yaml config = yaml.load(config_fd) if 'defaults' not in config: config['defaults'] = {} if 'server_key' not in config: config['server_key'] = ACME_DEFAULT_SERVER_KEY if 'account_key' not in config: config['account_key'] = ACME_DEFAULT_ACCOUNT_KEY config['domains'] = [] # load domain configuration for config_file in os.listdir(ACME_CONFD): if config_file.endswith(".conf"): with open(os.path.join(ACME_CONFD, config_file)) as config_fd: try: import json for entry in json.load(config_fd).items(): config['domains'].append(entry) except json.JSONDecodeError: import yaml for entry in yaml.load(config_fd).items(): config['domains'].append(entry) # post-update actions (run only once) actions = set() # check certificate validity and obtain/renew certificates if needed for domains, domaincfgs in config['domains']: # skip domains without any output files if domaincfgs is None: continue crt_file = os.path.join(ACME_DIR, (hashlib.md5(domains).hexdigest() + ".crt")) ttl_days = int(config.get('ttl_days', 15)) if not tools.is_cert_valid(crt_file, ttl_days): # Get certificates using handler configs (contain element 'mode') cert_get(domains, config, [x for x in domaincfgs if 'mode' in x]) # Run actions from config (contain element 'path') for actioncfg in [x for x in domaincfgs if 'path' in x]: actioncfg = complete_config(actioncfg, config) if not target_is_current(actioncfg['path'], crt_file): actions.add(cert_put(actioncfg)) # run post-update actions for action in actions: if action is not None: subprocess.call(action.split())