cathead/cathead/certwatch.py

101 lines
3.3 KiB
Python

# Copyright 2015 Tom Cammann
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import datetime
import logging
import os.path
import x509
LOG = logging.getLogger(__name__)
class CertWatcher(object):
def __init__(self, key_path, cert_path, common_name, ca_driver,
on_refresh_success=None, on_refresh_failure=None,
refresh_window=None):
if not os.path.isfile(key_path):
raise Exception("key needs to exist")
self.key_path = key_path
self.cert_path = cert_path
self.ca_driver = ca_driver
self.on_refresh_success = on_refresh_success
self.on_refresh_failure = on_refresh_failure
self.common_name = common_name
self.refresh_window = refresh_window
@property
def key(self):
return open(self.key_path).read()
@property
def cert(self):
return open(self.cert_path).read()
def get_expire_date(self):
return x509.get_expire_date(self.cert)
def seconds_until_expiry(self):
diff = self.get_expire_date() - datetime.datetime.now()
return diff.total_seconds()
def _replace_cert(self, cert_contents):
LOG.info("Replacing certificate at %s" % self.cert_path)
cert = open(self.cert_path, "w")
cert.write(cert_contents)
cert.close()
def _will_be_expired(self, date):
return date > self.get_expire_date()
def _expires_in_window(self):
now = datetime.datetime.now()
if not self.refresh_window:
LOG.debug("No refresh window set, assuming expired")
return True
window = now + datetime.timedelta(0, self.refresh_window)
if self._will_be_expired(window):
LOG.info("%s is expired inside window of %s"
% (self.cert_path, self.refresh_window))
return True
LOG.info("Certificate valid within window of %s seconds"
% self.refresh_window)
return False
def _cert_exists(self):
if not os.path.isfile(self.cert_path):
LOG.info("No cert found at %s" % self.cert_path)
return False
return True
def is_invalid_cert(self):
return not self._cert_exists() or self._expires_in_window()
def check_and_update(self):
LOG.info('Checking validity of certificate %s' % self.cert_path)
if self.is_invalid_cert():
csr = x509.generate_csr(self.key, self.common_name)
cert = None
try:
cert = self.ca_driver.sign(csr)
except Exception as e:
LOG.exception("Could not retrieve cert\n%s", e)
if cert:
self._replace_cert(cert)
self.on_refresh_success()
else:
self.on_refresh_failure()