openstack/charm-neutron-gateway
Code Issues Proposed changes

Add hardening support

Browse Source 
Add charmhelpers.contrib.hardening and calls to install,
config-changed, upgrade-charm and update-status hooks.
Also add new config option to allow one or more hardening
modules to be applied at runtime.

Change-Id: I0f3035c8f8feae90ad3572297fab0ac28e7d97e2
This commit is contained in:
Edward Hope-Morley 2016-03-22 21:00:39 +00:00
parent 7d7c690920
commit 7f5acef378
74 changed files with 4814 additions and 258 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
charm-helpers-hooks.yaml
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@ -12,3 +12,4 @@ include:
- contrib.python
- payload
- contrib.charmsupport
- contrib.hardening|inc=*

6
config.yaml
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@ -226,3 +226,9 @@ options:
wait for you to execute the openstack-upgrade action for this charm on
each unit. If False it will revert to existing behavior of upgrading
all units on config change.
harden:
default:
type: string
description: |
Apply system hardening. Supports a space-delimited list of modules
to run. Supported modules currently include os, ssh, apache and mysql.

5
hardening.yaml Normal file
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@ -0,0 +1,5 @@
# Overrides file for contrib.hardening. See README.hardening in
# contrib.hardening for info on how to use this file.
ssh:
server:
use_pam: 'yes' # juju requires this

38
hooks/charmhelpers/contrib/hardening/README.hardening.md Normal file
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@ -0,0 +1,38 @@
# Juju charm-helpers hardening library
## Description
This library provides multiple implementations of system and application
hardening that conform to the standards of http://hardening.io/.
Current implementations include:
* OS
* SSH
* MySQL
* Apache
## Requirements
* Juju Charms
## Usage
1. Synchronise this library into your charm and add the harden() decorator
(from contrib.hardening.harden) to any functions or methods you want to use
to trigger hardening of your application/system.
2. Add a config option called 'harden' to your charm config.yaml and set it to
a space-delimited list of hardening modules you want to run e.g. "os ssh"
3. Override any config defaults (contrib.hardening.defaults) by adding a file
called hardening.yaml to your charm root containing the name(s) of the
modules whose settings you want override at root level and then any settings
with overrides e.g.
os:
general:
desktop_enable: True
4. Now just run your charm as usual and hardening will be applied each time the
hook runs.

15
hooks/charmhelpers/contrib/hardening/__init__.py Normal file
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@ -0,0 +1,15 @@
# Copyright 2016 Canonical Limited.
#
# This file is part of charm-helpers.
#
# charm-helpers is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License version 3 as
# published by the Free Software Foundation.
#
# charm-helpers is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with charm-helpers. If not, see <http://www.gnu.org/licenses/>.

19
hooks/charmhelpers/contrib/hardening/apache/__init__.py Normal file
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@ -0,0 +1,19 @@
# Copyright 2016 Canonical Limited.
#
# This file is part of charm-helpers.
#
# charm-helpers is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License version 3 as
# published by the Free Software Foundation.
#
# charm-helpers is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with charm-helpers. If not, see <http://www.gnu.org/licenses/>.
from os import path
TEMPLATES_DIR = path.join(path.dirname(__file__), 'templates')

31
hooks/charmhelpers/contrib/hardening/apache/checks/__init__.py Normal file
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@ -0,0 +1,31 @@
# Copyright 2016 Canonical Limited.
#
# This file is part of charm-helpers.
#
# charm-helpers is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License version 3 as
# published by the Free Software Foundation.
#
# charm-helpers is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with charm-helpers. If not, see <http://www.gnu.org/licenses/>.
from charmhelpers.core.hookenv import (
log,
DEBUG,
)
from charmhelpers.contrib.hardening.apache.checks import config
def run_apache_checks():
log("Starting Apache hardening checks.", level=DEBUG)
checks = config.get_audits()
for check in checks:
log("Running '%s' check" % (check.__class__.__name__), level=DEBUG)
check.ensure_compliance()
log("Apache hardening checks complete.", level=DEBUG)

100
hooks/charmhelpers/contrib/hardening/apache/checks/config.py Normal file
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@ -0,0 +1,100 @@
# Copyright 2016 Canonical Limited.
#
# This file is part of charm-helpers.
#
# charm-helpers is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License version 3 as
# published by the Free Software Foundation.
#
# charm-helpers is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with charm-helpers. If not, see <http://www.gnu.org/licenses/>.
import os
import re
import subprocess
from charmhelpers.core.hookenv import (
log,
INFO,
)
from charmhelpers.contrib.hardening.audits.file import (
FilePermissionAudit,
DirectoryPermissionAudit,
NoReadWriteForOther,
TemplatedFile,
)
from charmhelpers.contrib.hardening.audits.apache import DisabledModuleAudit
from charmhelpers.contrib.hardening.apache import TEMPLATES_DIR
from charmhelpers.contrib.hardening import utils
def get_audits():
"""Get Apache hardening config audits.
:returns: dictionary of audits
"""
if subprocess.call(['which', 'apache2'], stdout=subprocess.PIPE) != 0:
log("Apache server does not appear to be installed on this node - "
"skipping apache hardening", level=INFO)
return []
context = ApacheConfContext()
settings = utils.get_settings('apache')
audits = [
FilePermissionAudit(paths='/etc/apache2/apache2.conf', user='root',
group='root', mode=0o0640),
TemplatedFile(os.path.join(settings['common']['apache_dir'],
'mods-available/alias.conf'),
context,
TEMPLATES_DIR,
mode=0o0755,
user='root',
service_actions=[{'service': 'apache2',
'actions': ['restart']}]),
TemplatedFile(os.path.join(settings['common']['apache_dir'],
'conf-enabled/hardening.conf'),
context,
TEMPLATES_DIR,
mode=0o0640,
user='root',
service_actions=[{'service': 'apache2',
'actions': ['restart']}]),
DirectoryPermissionAudit(settings['common']['apache_dir'],
user='root',
group='root',
mode=0o640),
DisabledModuleAudit(settings['hardening']['modules_to_disable']),
NoReadWriteForOther(settings['common']['apache_dir']),
]
return audits
class ApacheConfContext(object):
"""Defines the set of key/value pairs to set in a apache config file.
This context, when called, will return a dictionary containing the
key/value pairs of setting to specify in the
/etc/apache/conf-enabled/hardening.conf file.
"""
def __call__(self):
settings = utils.get_settings('apache')
ctxt = settings['hardening']
out = subprocess.check_output(['apache2', '-v'])
ctxt['apache_version'] = re.search(r'.+version: Apache/(.+?)\s.+',
out).group(1)
ctxt['apache_icondir'] = '/usr/share/apache2/icons/'
ctxt['traceenable'] = settings['hardening']['traceenable']
return ctxt

0
hooks/charmhelpers/contrib/hardening/apache/templates/__init__.py Normal file
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31
hooks/charmhelpers/contrib/hardening/apache/templates/alias.conf Normal file
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@ -0,0 +1,31 @@
###############################################################################
# WARNING: This configuration file is maintained by Juju. Local changes may
# be overwritten.
###############################################################################
<IfModule alias_module>
#
# Aliases: Add here as many aliases as you need (with no limit). The format is
# Alias fakename realname
#
# Note that if you include a trailing / on fakename then the server will
# require it to be present in the URL. So "/icons" isn't aliased in this
# example, only "/icons/". If the fakename is slash-terminated, then the
# realname must also be slash terminated, and if the fakename omits the
# trailing slash, the realname must also omit it.
#
# We include the /icons/ alias for FancyIndexed directory listings. If
# you do not use FancyIndexing, you may comment this out.
#
Alias /icons/ "{{ apache_icondir }}/"
<Directory "{{ apache_icondir }}">
Options -Indexes -MultiViews -FollowSymLinks
AllowOverride None
{% if apache_version == '2.4' -%}
Require all granted
{% else -%}
Order allow,deny
Allow from all
{% endif %}
</Directory>
</IfModule>

18
hooks/charmhelpers/contrib/hardening/apache/templates/hardening.conf Normal file
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@ -0,0 +1,18 @@
###############################################################################
# WARNING: This configuration file is maintained by Juju. Local changes may
# be overwritten.
###############################################################################
<Location / >
<LimitExcept {{ allowed_http_methods }} >
# http://httpd.apache.org/docs/2.4/upgrading.html
{% if apache_version > '2.2' -%}
Require all granted
{% else -%}
Order Allow,Deny
Deny from all
{% endif %}
</LimitExcept>
</Location>
TraceEnable {{ traceenable }}

63
hooks/charmhelpers/contrib/hardening/audits/__init__.py Normal file
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@ -0,0 +1,63 @@
# Copyright 2016 Canonical Limited.
#
# This file is part of charm-helpers.
#
# charm-helpers is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License version 3 as
# published by the Free Software Foundation.
#
# charm-helpers is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with charm-helpers. If not, see <http://www.gnu.org/licenses/>.
class BaseAudit(object): # NO-QA
"""Base class for hardening checks.
The lifecycle of a hardening check is to first check to see if the system
is in compliance for the specified check. If it is not in compliance, the
check method will return a value which will be supplied to the.
"""
def __init__(self, *args, **kwargs):
self.unless = kwargs.get('unless', None)
super(BaseAudit, self).__init__()
def ensure_compliance(self):
"""Checks to see if the current hardening check is in compliance or
not.
If the check that is performed is not in compliance, then an exception
should be raised.
"""
pass
def _take_action(self):
"""Determines whether to perform the action or not.
Checks whether or not an action should be taken. This is determined by
the truthy value for the unless parameter. If unless is a callback
method, it will be invoked with no parameters in order to determine
whether or not the action should be taken. Otherwise, the truthy value
of the unless attribute will determine if the action should be
performed.
"""
# Do the action if there isn't an unless override.
if self.unless is None:
return True
# Invoke the callback if there is one.
if hasattr(self.unless, '__call__'):
results = self.unless()
if results:
return False
else:
return True
if self.unless:
return False
else:
return True

100
hooks/charmhelpers/contrib/hardening/audits/apache.py Normal file
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@ -0,0 +1,100 @@
# Copyright 2016 Canonical Limited.
#
# This file is part of charm-helpers.
#
# charm-helpers is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License version 3 as
# published by the Free Software Foundation.
#
# charm-helpers is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with charm-helpers. If not, see <http://www.gnu.org/licenses/>.
import re
import subprocess
from six import string_types
from charmhelpers.core.hookenv import (
log,
INFO,
ERROR,
)
from charmhelpers.contrib.hardening.audits import BaseAudit
class DisabledModuleAudit(BaseAudit):
"""Audits Apache2 modules.
Determines if the apache2 modules are enabled. If the modules are enabled
then they are removed in the ensure_compliance.
"""
def __init__(self, modules):
if modules is None:
self.modules = []
elif isinstance(modules, string_types):
self.modules = [modules]
else:
self.modules = modules
def ensure_compliance(self):
"""Ensures that the modules are not loaded."""
if not self.modules:
return
try:
loaded_modules = self._get_loaded_modules()
non_compliant_modules = []
for module in self.modules:
if module in loaded_modules:
log("Module '%s' is enabled but should not be." %
(module), level=INFO)
non_compliant_modules.append(module)
if len(non_compliant_modules) == 0:
return
for module in non_compliant_modules:
self._disable_module(module)
self._restart_apache()
except subprocess.CalledProcessError as e:
log('Error occurred auditing apache module compliance. '
'This may have been already reported. '
'Output is: %s' % e.output, level=ERROR)
@staticmethod
def _get_loaded_modules():
"""Returns the modules which are enabled in Apache."""
output = subprocess.check_output(['apache2ctl', '-M'])
modules = []
for line in output.strip().split():
# Each line of the enabled module output looks like:
# module_name (static|shared)
# Plus a header line at the top of the output which is stripped
# out by the regex.
matcher = re.search(r'^ (\S*)', line)
if matcher:
modules.append(matcher.group(1))
return modules
@staticmethod
def _disable_module(module):
"""Disables the specified module in Apache."""
try:
subprocess.check_call(['a2dismod', module])
except subprocess.CalledProcessError as e:
# Note: catch error here to allow the attempt of disabling
# multiple modules in one go rather than failing after the
# first module fails.
log('Error occurred disabling module %s. '
'Output is: %s' % (module, e.output), level=ERROR)
@staticmethod
def _restart_apache():
"""Restarts the apache process"""
subprocess.check_output(['service', 'apache2', 'restart'])

105
hooks/charmhelpers/contrib/hardening/audits/apt.py Normal file
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@ -0,0 +1,105 @@
# Copyright 2016 Canonical Limited.
#
# This file is part of charm-helpers.
#
# charm-helpers is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License version 3 as
# published by the Free Software Foundation.
#
# charm-helpers is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with charm-helpers. If not, see <http://www.gnu.org/licenses/>.
from __future__ import absolute_import # required for external apt import
from apt import apt_pkg
from six import string_types
from charmhelpers.fetch import (
apt_cache,
apt_purge
)
from charmhelpers.core.hookenv import (
log,
DEBUG,
WARNING,
)
from charmhelpers.contrib.hardening.audits import BaseAudit
class AptConfig(BaseAudit):
def __init__(self, config, **kwargs):
self.config = config
def verify_config(self):
apt_pkg.init()
for cfg in self.config:
value = apt_pkg.config.get(cfg['key'], cfg.get('default', ''))
if value and value != cfg['expected']:
log("APT config '%s' has unexpected value '%s' "
"(expected='%s')" %
(cfg['key'], value, cfg['expected']), level=WARNING)
def ensure_compliance(self):
self.verify_config()
class RestrictedPackages(BaseAudit):
"""Class used to audit restricted packages on the system."""
def __init__(self, pkgs, **kwargs):
super(RestrictedPackages, self).__init__(**kwargs)
if isinstance(pkgs, string_types) or not hasattr(pkgs, '__iter__'):
self.pkgs = [pkgs]
else:
self.pkgs = pkgs
def ensure_compliance(self):
cache = apt_cache()
for p in self.pkgs:
if p not in cache:
continue
pkg = cache[p]
if not self.is_virtual_package(pkg):
if not pkg.current_ver:
log("Package '%s' is not installed." % pkg.name,
level=DEBUG)
continue
else:
log("Restricted package '%s' is installed" % pkg.name,
level=WARNING)
self.delete_package(cache, pkg)
else:
log("Checking restricted virtual package '%s' provides" %
pkg.name, level=DEBUG)
self.delete_package(cache, pkg)
def delete_package(self, cache, pkg):
"""Deletes the package from the system.
Deletes the package form the system, properly handling virtual
packages.
:param cache: the apt cache
:param pkg: the package to remove
"""
if self.is_virtual_package(pkg):
log("Package '%s' appears to be virtual - purging provides" %
pkg.name, level=DEBUG)
for _p in pkg.provides_list:
self.delete_package(cache, _p[2].parent_pkg)
elif not pkg.current_ver:
log("Package '%s' not installed" % pkg.name, level=DEBUG)
return
else:
log("Purging package '%s'" % pkg.name, level=DEBUG)
apt_purge(pkg.name)
def is_virtual_package(self, pkg):
return pkg.has_provides and not pkg.has_versions

552
hooks/charmhelpers/contrib/hardening/audits/file.py Normal file
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@ -0,0 +1,552 @@
# Copyright 2016 Canonical Limited.
#
# This file is part of charm-helpers.
#
# charm-helpers is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License version 3 as
# published by the Free Software Foundation.
#
# charm-helpers is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with charm-helpers. If not, see <http://www.gnu.org/licenses/>.
import grp
import os
import pwd
import re
from subprocess import (
CalledProcessError,
check_output,
check_call,
)
from traceback import format_exc
from six import string_types
from stat import (
S_ISGID,
S_ISUID
)
from charmhelpers.core.hookenv import (
log,
DEBUG,
INFO,
WARNING,
ERROR,
)
from charmhelpers.core import unitdata
from charmhelpers.core.host import file_hash
from charmhelpers.contrib.hardening.audits import BaseAudit
from charmhelpers.contrib.hardening.templating import (
get_template_path,
render_and_write,
)
from charmhelpers.contrib.hardening import utils
class BaseFileAudit(BaseAudit):
"""Base class for file audits.
Provides api stubs for compliance check flow that must be used by any class
that implemented this one.
"""
def __init__(self, paths, always_comply=False, *args, **kwargs):
"""
:param paths: string path of list of paths of files we want to apply
compliance checks are criteria to.
:param always_comply: if true compliance criteria is always applied
else compliance is skipped for non-existent
paths.
"""
super(BaseFileAudit, self).__init__(*args, **kwargs)
self.always_comply = always_comply
if isinstance(paths, string_types) or not hasattr(paths, '__iter__'):
self.paths = [paths]
else:
self.paths = paths
def ensure_compliance(self):
"""Ensure that the all registered files comply to registered criteria.
"""
for p in self.paths:
if os.path.exists(p):
if self.is_compliant(p):
continue
log('File %s is not in compliance.' % p, level=INFO)
else:
if not self.always_comply:
log("Non-existent path '%s' - skipping compliance check"
% (p), level=INFO)
continue
if self._take_action():
log("Applying compliance criteria to '%s'" % (p), level=INFO)
self.comply(p)
def is_compliant(self, path):
"""Audits the path to see if it is compliance.
:param path: the path to the file that should be checked.
"""
raise NotImplementedError
def comply(self, path):
"""Enforces the compliance of a path.
:param path: the path to the file that should be enforced.
"""
raise NotImplementedError
@classmethod
def _get_stat(cls, path):
"""Returns the Posix st_stat information for the specified file path.
:param path: the path to get the st_stat information for.
:returns: an st_stat object for the path or None if the path doesn't
exist.
"""
return os.stat(path)
class FilePermissionAudit(BaseFileAudit):
"""Implements an audit for file permissions and ownership for a user.
This class implements functionality that ensures that a specific user/group
will own the file(s) specified and that the permissions specified are
applied properly to the file.
"""
def __init__(self, paths, user, group=None, mode=0o600, **kwargs):
self.user = user
self.group = group
self.mode = mode
super(FilePermissionAudit, self).__init__(paths, user, group, mode,
**kwargs)
@property
def user(self):
return self._user
@user.setter
def user(self, name):
try:
user = pwd.getpwnam(name)
except KeyError:
log('Unknown user %s' % name, level=ERROR)
user = None
self._user = user
@property
def group(self):
return self._group
@group.setter
def group(self, name):
try:
group = None
if name:
group = grp.getgrnam(name)
else:
group = grp.getgrgid(self.user.pw_gid)
except KeyError:
log('Unknown group %s' % name, level=ERROR)
self._group = group
def is_compliant(self, path):
"""Checks if the path is in compliance.
Used to determine if the path specified meets the necessary
requirements to be in compliance with the check itself.
:param path: the file path to check
:returns: True if the path is compliant, False otherwise.
"""
stat = self._get_stat(path)
user = self.user
group = self.group
compliant = True
if stat.st_uid != user.pw_uid or stat.st_gid != group.gr_gid:
log('File %s is not owned by %s:%s.' % (path, user.pw_name,
group.gr_name),
level=INFO)
compliant = False
# POSIX refers to the st_mode bits as corresponding to both the
# file type and file permission bits, where the least significant 12
# bits (o7777) are the suid (11), sgid (10), sticky bits (9), and the
# file permission bits (8-0)
perms = stat.st_mode & 0o7777
if perms != self.mode:
log('File %s has incorrect permissions, currently set to %s' %
(path, oct(stat.st_mode & 0o7777)), level=INFO)
compliant = False
return compliant
def comply(self, path):
"""Issues a chown and chmod to the file paths specified."""
utils.ensure_permissions(path, self.user.pw_name, self.group.gr_name,
self.mode)
class DirectoryPermissionAudit(FilePermissionAudit):
"""Performs a permission check for the specified directory path."""
def __init__(self, paths, user, group=None, mode=0o600,
recursive=True, **kwargs):
super(DirectoryPermissionAudit, self).__init__(paths, user, group,
mode, **kwargs)
self.recursive = recursive
def is_compliant(self, path):
"""Checks if the directory is compliant.
Used to determine if the path specified and all of its children
directories are in compliance with the check itself.
:param path: the directory path to check
:returns: True if the directory tree is compliant, otherwise False.
"""
if not os.path.isdir(path):
log('Path specified %s is not a directory.' % path, level=ERROR)
raise ValueError("%s is not a directory." % path)
if not self.recursive:
return super(DirectoryPermissionAudit, self).is_compliant(path)
compliant = True
for root, dirs, _ in os.walk(path):
if len(dirs) > 0:
continue
if not super(DirectoryPermissionAudit, self).is_compliant(root):
compliant = False
continue
return compliant
def comply(self, path):
for root, dirs, _ in os.walk(path):
if len(dirs) > 0:
super(DirectoryPermissionAudit, self).comply(root)
class ReadOnly(BaseFileAudit):
"""Audits that files and folders are read only."""
def __init__(self, paths, *args, **kwargs):
super(ReadOnly, self).__init__(paths=paths, *args, **kwargs)
def is_compliant(self, path):
try:
output = check_output(['find', path, '-perm', '-go+w',
'-type', 'f']).strip()
# The find above will find any files which have permission sets
# which allow too broad of write access. As such, the path is
# compliant if there is no output.
if output:
return False
return True
except CalledProcessError as e:
log('Error occurred checking finding writable files for %s. '
'Error information is: command %s failed with returncode '
'%d and output %s.\n%s' % (path, e.cmd, e.returncode, e.output,
format_exc(e)), level=ERROR)
return False
def comply(self, path):
try:
check_output(['chmod', 'go-w', '-R', path])
except CalledProcessError as e:
log('Error occurred removing writeable permissions for %s. '
'Error information is: command %s failed with returncode '
'%d and output %s.\n%s' % (path, e.cmd, e.returncode, e.output,
format_exc(e)), level=ERROR)
class NoReadWriteForOther(BaseFileAudit):
"""Ensures that the files found under the base path are readable or
writable by anyone other than the owner or the group.
"""
def __init__(self, paths):
super(NoReadWriteForOther, self).__init__(paths)
def is_compliant(self, path):
try:
cmd = ['find', path, '-perm', '-o+r', '-type', 'f', '-o',
'-perm', '-o+w', '-type', 'f']
output = check_output(cmd).strip()
# The find above here will find any files which have read or
# write permissions for other, meaning there is too broad of access
# to read/write the file. As such, the path is compliant if there's
# no output.
if output:
return False
return True
except CalledProcessError as e:
log('Error occurred while finding files which are readable or '
'writable to the world in %s. '
'Command output is: %s.' % (path, e.output), level=ERROR)
def comply(self, path):
try:
check_output(['chmod', '-R', 'o-rw', path])
except CalledProcessError as e:
log('Error occurred attempting to change modes of files under '
'path %s. Output of command is: %s' % (path, e.output))
class NoSUIDSGIDAudit(BaseFileAudit):
"""Audits that specified files do not have SUID/SGID bits set."""
def __init__(self, paths, *args, **kwargs):
super(NoSUIDSGIDAudit, self).__init__(paths=paths, *args, **kwargs)
def is_compliant(self, path):
stat = self._get_stat(path)
if (stat.st_mode & (S_ISGID | S_ISUID)) != 0:
return False
return True
def comply(self, path):
try:
log('Removing suid/sgid from %s.' % path, level=DEBUG)
check_output(['chmod', '-s', path])
except CalledProcessError as e:
log('Error occurred removing suid/sgid from %s.'
'Error information is: command %s failed with returncode '
'%d and output %s.\n%s' % (path, e.cmd, e.returncode, e.output,
format_exc(e)), level=ERROR)
class TemplatedFile(BaseFileAudit):
"""The TemplatedFileAudit audits the contents of a templated file.
This audit renders a file from a template, sets the appropriate file
permissions, then generates a hashsum with which to check the content
changed.
"""
def __init__(self, path, context, template_dir, mode, user='root',
group='root', service_actions=None, **kwargs):
self.context = context
self.user = user
self.group = group
self.mode = mode
self.template_dir = template_dir
self.service_actions = service_actions
super(TemplatedFile, self).__init__(paths=path, always_comply=True,
**kwargs)
def is_compliant(self, path):
"""Determines if the templated file is compliant.
A templated file is only compliant if it has not changed (as
determined by its sha256 hashsum) AND its file permissions are set
appropriately.
:param path: the path to check compliance.
"""
same_templates = self.templates_match(path)
same_content = self.contents_match(path)
same_permissions = self.permissions_match(path)
if same_content and same_permissions and same_templates:
return True
return False
def run_service_actions(self):
"""Run any actions on services requested."""
if not self.service_actions:
return
for svc_action in self.service_actions:
name = svc_action['service']
actions = svc_action['actions']
log("Running service '%s' actions '%s'" % (name, actions),
level=DEBUG)
for action in actions:
cmd = ['service', name, action]
try:
check_call(cmd)
except CalledProcessError as exc:
log("Service name='%s' action='%s' failed - %s" %
(name, action, exc), level=WARNING)
def comply(self, path):
"""Ensures the contents and the permissions of the file.
:param path: the path to correct
"""
dirname = os.path.dirname(path)
if not os.path.exists(dirname):
os.makedirs(dirname)
self.pre_write()
render_and_write(self.template_dir, path, self.context())
utils.ensure_permissions(path, self.user, self.group, self.mode)
self.run_service_actions()
self.save_checksum(path)
self.post_write()
def pre_write(self):
"""Invoked prior to writing the template."""
pass
def post_write(self):
"""Invoked after writing the template."""
pass
def templates_match(self, path):
"""Determines if the template files are the same.
The template file equality is determined by the hashsum of the
template files themselves. If there is no hashsum, then the content
cannot be sure to be the same so treat it as if they changed.
Otherwise, return whether or not the hashsums are the same.
:param path: the path to check
:returns: boolean
"""
template_path = get_template_path(self.template_dir, path)
key = 'hardening:template:%s' % template_path
template_checksum = file_hash(template_path)
kv = unitdata.kv()
stored_tmplt_checksum = kv.get(key)
if not stored_tmplt_checksum:
kv.set(key, template_checksum)
kv.flush()
log('Saved template checksum for %s.' % template_path,
level=DEBUG)
# Since we don't have a template checksum, then assume it doesn't
# match and return that the template is different.
return False
elif stored_tmplt_checksum != template_checksum:
kv.set(key, template_checksum)
kv.flush()
log('Updated template checksum for %s.' % template_path,
level=DEBUG)
return False
# Here the template hasn't changed based upon the calculated
# checksum of the template and what was previously stored.
return True
def contents_match(self, path):
"""Determines if the file content is the same.
This is determined by comparing hashsum of the file contents and
the saved hashsum. If there is no hashsum, then the content cannot
be sure to be the same so treat them as if they are not the same.
Otherwise, return True if the hashsums are the same, False if they
are not the same.
:param path: the file to check.
"""
checksum = file_hash(path)
kv = unitdata.kv()
stored_checksum = kv.get('hardening:%s' % path)
if not stored_checksum:
# If the checksum hasn't been generated, return False to ensure
# the file is written and the checksum stored.
log('Checksum for %s has not been calculated.' % path, level=DEBUG)
return False
elif stored_checksum != checksum:
log('Checksum mismatch for %s.' % path, level=DEBUG)
return False
return True
def permissions_match(self, path):
"""Determines if the file owner and permissions match.
:param path: the path to check.
"""
audit = FilePermissionAudit(path, self.user, self.group, self.mode)
return audit.is_compliant(path)
def save_checksum(self, path):
"""Calculates and saves the checksum for the path specified.
:param path: the path of the file to save the checksum.
"""
checksum = file_hash(path)
kv = unitdata.kv()
kv.set('hardening:%s' % path, checksum)
kv.flush()
class DeletedFile(BaseFileAudit):
"""Audit to ensure that a file is deleted."""
def __init__(self, paths):
super(DeletedFile, self).__init__(paths)
def is_compliant(self, path):
return not os.path.exists(path)
def comply(self, path):
os.remove(path)
class FileContentAudit(BaseFileAudit):
"""Audit the contents of a file."""
def __init__(self, paths, cases, **kwargs):
# Cases we expect to pass
self.pass_cases = cases.get('pass', [])
# Cases we expect to fail
self.fail_cases = cases.get('fail', [])
super(FileContentAudit, self).__init__(paths, **kwargs)
def is_compliant(self, path):
"""
Given a set of content matching cases i.e. tuple(regex, bool) where
bool value denotes whether or not regex is expected to match, check that
all cases match as expected with the contents of the file. Cases can be
expected to pass of fail.
:param path: Path of file to check.
:returns: Boolean value representing whether or not all cases are
found to be compliant.
"""
log("Auditing contents of file '%s'" % (path), level=DEBUG)
with open(path, 'r') as fd:
contents = fd.read()
matches = 0
for pattern in self.pass_cases:
key = re.compile(pattern, flags=re.MULTILINE)
results = re.search(key, contents)
if results:
matches += 1
else:
log("Pattern '%s' was expected to pass but instead it failed"
% (pattern), level=WARNING)
for pattern in self.fail_cases:
key = re.compile(pattern, flags=re.MULTILINE)
results = re.search(key, contents)
if not results:
matches += 1
else:
log("Pattern '%s' was expected to fail but instead it passed"
% (pattern), level=WARNING)
total = len(self.pass_cases) + len(self.fail_cases)
log("Checked %s cases and %s passed" % (total, matches), level=DEBUG)
return matches == total
def comply(self, *args, **kwargs):
"""NOOP since we just issue warnings. This is to avoid the
NotImplememtedError.
"""
log("Not applying any compliance criteria, only checks.", level=INFO)

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# NOTE: this file contains the default configuration for the 'apache' hardening
# code. If you want to override any settings you must add them to a file
# called hardening.yaml in the root directory of your charm using the
# name 'apache' as the root key followed by any of the following with new
# values.
common:
apache_dir: '/etc/apache2'
hardening:
traceenable: 'off'
allowed_http_methods: "GET POST"
modules_to_disable: [ cgi, cgid ]

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# NOTE: this schema must contain all valid keys from it's associated defaults
# file. It is used to validate user-provided overrides.
common:
apache_dir:
traceenable:
hardening:
allowed_http_methods:
modules_to_disable:

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# NOTE: this file contains the default configuration for the 'mysql' hardening
# code. If you want to override any settings you must add them to a file
# called hardening.yaml in the root directory of your charm using the
# name 'mysql' as the root key followed by any of the following with new
# values.
hardening:
mysql-conf: /etc/mysql/my.cnf
hardening-conf: /etc/mysql/conf.d/hardening.cnf
security:
# @see http://www.symantec.com/connect/articles/securing-mysql-step-step
# @see http://dev.mysql.com/doc/refman/5.7/en/server-options.html#option_mysqld_chroot
chroot: None
# @see http://dev.mysql.com/doc/refman/5.7/en/server-options.html#option_mysqld_safe-user-create
safe-user-create: 1
# @see http://dev.mysql.com/doc/refman/5.7/en/server-options.html#option_mysqld_secure-auth
secure-auth: 1
# @see http://dev.mysql.com/doc/refman/5.7/en/server-options.html#option_mysqld_symbolic-links
skip-symbolic-links: 1
# @see http://dev.mysql.com/doc/refman/5.7/en/server-options.html#option_mysqld_skip-show-database
skip-show-database: True
# @see http://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_local_infile
local-infile: 0
# @see https://dev.mysql.com/doc/refman/5.7/en/server-options.html#option_mysqld_allow-suspicious-udfs
allow-suspicious-udfs: 0
# @see https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_automatic_sp_privileges
automatic-sp-privileges: 0
# @see https://dev.mysql.com/doc/refman/5.7/en/server-options.html#option_mysqld_secure-file-priv
secure-file-priv: /tmp

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# NOTE: this schema must contain all valid keys from it's associated defaults
# file. It is used to validate user-provided overrides.
hardening:
mysql-conf:
hardening-conf:
security:
chroot:
safe-user-create:
secure-auth:
skip-symbolic-links:
skip-show-database:
local-infile:
allow-suspicious-udfs:
automatic-sp-privileges:
secure-file-priv:

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# NOTE: this file contains the default configuration for the 'os' hardening
# code. If you want to override any settings you must add them to a file
# called hardening.yaml in the root directory of your charm using the
# name 'os' as the root key followed by any of the following with new
# values.
general:
desktop_enable: False # (type:boolean)
environment:
extra_user_paths: []
umask: 027
root_path: /
auth:
pw_max_age: 60
# discourage password cycling
pw_min_age: 7
retries: 5
lockout_time: 600
timeout: 60
allow_homeless: False # (type:boolean)
pam_passwdqc_enable: True # (type:boolean)
pam_passwdqc_options: 'min=disabled,disabled,16,12,8'
root_ttys:
console
tty1
tty2
tty3
tty4
tty5
tty6
uid_min: 1000
gid_min: 1000
sys_uid_min: 100
sys_uid_max: 999
sys_gid_min: 100
sys_gid_max: 999
chfn_restrict:
security:
users_allow: []
suid_sgid_enforce: True # (type:boolean)
# user-defined blacklist and whitelist
suid_sgid_blacklist: []
suid_sgid_whitelist: []
# if this is True, remove any suid/sgid bits from files that were not in the whitelist
suid_sgid_dry_run_on_unknown: False # (type:boolean)
suid_sgid_remove_from_unknown: False # (type:boolean)
# remove packages with known issues
packages_clean: True # (type:boolean)
packages_list:
xinetd
inetd
ypserv
telnet-server
rsh-server
rsync
kernel_enable_module_loading: True # (type:boolean)
kernel_enable_core_dump: False # (type:boolean)
sysctl:
kernel_secure_sysrq: 244 # 4 + 16 + 32 + 64 + 128
kernel_enable_sysrq: False # (type:boolean)
forwarding: False # (type:boolean)
ipv6_enable: False # (type:boolean)
arp_restricted: True # (type:boolean)

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# NOTE: this schema must contain all valid keys from it's associated defaults
# file. It is used to validate user-provided overrides.
general:
desktop_enable:
environment:
extra_user_paths:
umask:
root_path:
auth:
pw_max_age:
pw_min_age:
retries:
lockout_time:
timeout:
allow_homeless:
pam_passwdqc_enable:
pam_passwdqc_options:
root_ttys:
uid_min:
gid_min:
sys_uid_min:
sys_uid_max:
sys_gid_min:
sys_gid_max:
chfn_restrict:
security:
users_allow:
suid_sgid_enforce:
suid_sgid_blacklist:
suid_sgid_whitelist:
suid_sgid_dry_run_on_unknown:
suid_sgid_remove_from_unknown:
packages_clean:
packages_list:
kernel_enable_module_loading:
kernel_enable_core_dump:
sysctl:
kernel_secure_sysrq:
kernel_enable_sysrq:
forwarding:
ipv6_enable:
arp_restricted:

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# NOTE: this file contains the default configuration for the 'ssh' hardening
# code. If you want to override any settings you must add them to a file
# called hardening.yaml in the root directory of your charm using the
# name 'ssh' as the root key followed by any of the following with new
# values.
common:
service_name: 'ssh'
network_ipv6_enable: False # (type:boolean)
ports: [22]
remote_hosts: []
client:
package: 'openssh-client'
cbc_required: False # (type:boolean)
weak_hmac: False # (type:boolean)
weak_kex: False # (type:boolean)
roaming: False
password_authentication: 'no'
server:
host_key_files: ['/etc/ssh/ssh_host_rsa_key', '/etc/ssh/ssh_host_dsa_key',
'/etc/ssh/ssh_host_ecdsa_key']
cbc_required: False # (type:boolean)
weak_hmac: False # (type:boolean)
weak_kex: False # (type:boolean)
allow_root_with_key: False # (type:boolean)
allow_tcp_forwarding: 'no'
allow_agent_forwarding: 'no'
allow_x11_forwarding: 'no'
use_privilege_separation: 'sandbox'
listen_to: ['0.0.0.0']
use_pam: 'no'
package: 'openssh-server'
password_authentication: 'no'
alive_interval: '600'
alive_count: '3'
sftp_enable: False # (type:boolean)
sftp_group: 'sftponly'
sftp_chroot: '/home/%u'
deny_users: []
allow_users: []
deny_groups: []
allow_groups: []
print_motd: 'no'
print_last_log: 'no'
use_dns: 'no'
max_auth_tries: 2
max_sessions: 10

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# NOTE: this schema must contain all valid keys from it's associated defaults
# file. It is used to validate user-provided overrides.
common:
service_name:
network_ipv6_enable:
ports:
remote_hosts:
client:
package:
cbc_required:
weak_hmac:
weak_kex:
roaming:
password_authentication:
server:
host_key_files:
cbc_required:
weak_hmac:
weak_kex:
allow_root_with_key:
allow_tcp_forwarding:
allow_agent_forwarding:
allow_x11_forwarding:
use_privilege_separation:
listen_to:
use_pam:
package:
password_authentication:
alive_interval:
alive_count:
sftp_enable:
sftp_group:
sftp_chroot:
deny_users:
allow_users:
deny_groups:
allow_groups:
print_motd:
print_last_log:
use_dns:
max_auth_tries:
max_sessions:

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# Copyright 2016 Canonical Limited.
#
# This file is part of charm-helpers.
#
# charm-helpers is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License version 3 as
# published by the Free Software Foundation.
#
# charm-helpers is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with charm-helpers. If not, see <http://www.gnu.org/licenses/>.
import six
from collections import OrderedDict
from charmhelpers.core.hookenv import (
config,
log,
DEBUG,
WARNING,
)
from charmhelpers.contrib.hardening.host.checks import run_os_checks
from charmhelpers.contrib.hardening.ssh.checks import run_ssh_checks
from charmhelpers.contrib.hardening.mysql.checks import run_mysql_checks
from charmhelpers.contrib.hardening.apache.checks import run_apache_checks
def harden(overrides=None):
"""Hardening decorator.
This is the main entry point for running the hardening stack. In order to
run modules of the stack you must add this decorator to charm hook(s) and
ensure that your charm config.yaml contains the 'harden' option set to
one or more of the supported modules. Setting these will cause the
corresponding hardening code to be run when the hook fires.
This decorator can and should be applied to more than one hook or function
such that hardening modules are called multiple times. This is because
subsequent calls will perform auditing checks that will report any changes
to resources hardened by the first run (and possibly perform compliance
actions as a result of any detected infractions).
:param overrides: Optional list of stack modules used to override those
provided with 'harden' config.
:returns: Returns value returned by decorated function once executed.
"""
def _harden_inner1(f):
log("Hardening function '%s'" % (f.__name__), level=DEBUG)
def _harden_inner2(*args, **kwargs):
RUN_CATALOG = OrderedDict([('os', run_os_checks),
('ssh', run_ssh_checks),