tuskar-ui/horizon/utils/secret_key.py
Sascha Peilicke 9aa2dda073 Provide utilities to automate secure secret key generation
Implements blueprint automatic-secure-key-generation

Reduce the likeliness that the (commented-out) default key is abused
and document possible options instead.

Also use a non-empty SECRET_KEY for development / testing environments.

A later patch would make it a hard error if no SECRET_KEY is defined
(i.e. Django defaults to an empty string which is anything but secure).
Unfortunately, I can't do it now as the devstack integration test would
fail (they don't set a SECRET_KEY either) currently. So, when this
blueprint is accepted, I would submit a fix to devstack and afterwards
add the error message to warn the user about insecure defaults.

Addressed PEP-8 issues

Change-Id: Ifdab8e6b6fb3025fde7a2b92beb046ec9c5cba7f
2012-07-03 10:18:56 +02:00

69 lines
2.3 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2012 Nebula, Inc.
#
# 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.
from __future__ import with_statement # Python 2.5 compliance
import lockfile
import random
import string
import tempfile
import os
class FilePermissionError(Exception):
"""The key file permissions are insecure."""
pass
def generate_key(key_length=64):
"""Secret key generator.
The quality of randomness depends on operating system support,
see http://docs.python.org/library/random.html#random.SystemRandom.
"""
if hasattr(random, 'SystemRandom'):
choice = random.SystemRandom().choice
else:
choice = random.choice
return ''.join(map(lambda x: choice(string.digits + string.letters),
range(key_length)))
def generate_or_read_from_file(key_file='.secret_key', key_length=64):
"""Multiprocess-safe secret key file generator.
Useful to replace the default (and thus unsafe) SECRET_KEY in settings.py
upon first start. Save to use, i.e. when multiple Python interpreters
serve the dashboard Django application (e.g. in a mod_wsgi + daemonized
environment). Also checks if file permissions are set correctly and
throws an exception if not.
"""
lock = lockfile.FileLock(key_file)
with lock:
if not os.path.exists(key_file):
key = generate_key(key_length)
old_umask = os.umask(0177) # Use '0600' file permissions
with open(key_file, 'w') as f:
f.write(key)
os.umask(old_umask)
else:
if oct(os.stat(key_file).st_mode & 0777) != '0600':
raise FilePermissionError("Insecure key file permissions!")
with open(key_file, 'r') as f:
key = f.readline()
return key