mirror of
https://github.com/munki/munki.git
synced 2026-01-15 03:30:29 -06:00
986a45d395
git-svn-id: http://munki.googlecode.com/svn/trunk@1187 a4e17f2e-e282-11dd-95e1-755cbddbdd66
129 lines
4.3 KiB
Python
129 lines
4.3 KiB
Python
#!/usr/bin/python
|
|
# encoding: utf-8
|
|
#
|
|
# Copyright 2009-2011 Greg Neagle.
|
|
#
|
|
# 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.
|
|
"""
|
|
utils
|
|
|
|
Created by Justin McWilliams on 2010-10-26.
|
|
|
|
Common utility functions used throughout Munki.
|
|
|
|
Note: this module should be 100% free of ObjC-dependant Python imports.
|
|
"""
|
|
|
|
|
|
import grp
|
|
import os
|
|
import subprocess
|
|
import stat
|
|
|
|
|
|
class Error(Exception):
|
|
"""Class for domain specific exceptions."""
|
|
|
|
|
|
class RunExternalScriptError(Error):
|
|
"""There was an error running the script."""
|
|
|
|
|
|
class ScriptNotFoundError(RunExternalScriptError):
|
|
"""The script was not found at the given path."""
|
|
|
|
|
|
class VerifyFilePermissionsError(Error):
|
|
"""There was an error verifying file permissions."""
|
|
|
|
|
|
class InsecureFilePermissionsError(VerifyFilePermissionsError):
|
|
"""The permissions of the specified file are insecure."""
|
|
|
|
|
|
def verifyFileOnlyWritableByMunkiAndRoot(file_path):
|
|
"""
|
|
Check the permissions on a given file path; fail if owner or group
|
|
does not match the munki process (default: root/admin) or the group is not
|
|
'wheel', or if other users are able to write to the file. This prevents
|
|
escalated execution of arbitrary code.
|
|
|
|
Args:
|
|
file_path: str path of file to verify permissions on.
|
|
Raises:
|
|
VerifyFilePermissionsError: there was an error verifying file permissions.
|
|
InsecureFilePermissionsError: file permissions were found to be insecure.
|
|
"""
|
|
try:
|
|
file_stat = os.stat(file_path)
|
|
except OSError, e:
|
|
raise VerifyFilePermissionsError(
|
|
'%s does not exist. \n %s' % (file_path, str(e)))
|
|
|
|
try:
|
|
admin_gid = grp.getgrnam('admin').gr_gid
|
|
wheel_gid = grp.getgrnam('wheel').gr_gid
|
|
user_gid = os.getegid()
|
|
# verify the munki process uid matches the file owner uid.
|
|
if os.geteuid() != file_stat.st_uid:
|
|
raise InsecureFilePermissionsError(
|
|
'owner does not match munki process!')
|
|
# verify the munki process gid matches the file owner gid, or the file
|
|
# owner gid is wheel or admin gid.
|
|
elif file_stat.st_gid not in [admin_gid, wheel_gid, user_gid]:
|
|
raise InsecureFilePermissionsError(
|
|
'group does not match munki process!')
|
|
# verify other users cannot write to the file.
|
|
elif file_stat.st_mode & stat.S_IWOTH != 0:
|
|
raise InsecureFilePermissionsError('world writable!')
|
|
except InsecureFilePermissionsError, e:
|
|
raise InsecureFilePermissionsError(
|
|
'%s is not secure! %s' % (file_path, e.args[0]))
|
|
|
|
|
|
def runExternalScript(script, *args):
|
|
"""Run a script (e.g. preflight/postflight) and return its exit status.
|
|
|
|
Args:
|
|
script: string path to the script to execute.
|
|
args: args to pass to the script.
|
|
Returns:
|
|
Tuple. (integer exit status from script, str stdout, str stderr).
|
|
Raises:
|
|
ScriptNotFoundError: the script was not found at the given path.
|
|
RunExternalScriptError: there was an error running the script.
|
|
"""
|
|
if not os.path.exists(script):
|
|
raise ScriptNotFoundError('script does not exist: %s' % script)
|
|
|
|
try:
|
|
verifyFileOnlyWritableByMunkiAndRoot(script)
|
|
except VerifyFilePermissionsError, e:
|
|
msg = ('Skipping execution due to failed file permissions '
|
|
'verification: %s\n%s' % (script, str(e)))
|
|
raise RunExternalScriptError(msg)
|
|
|
|
if os.access(script, os.X_OK):
|
|
cmd = [script]
|
|
if args:
|
|
cmd.extend(args)
|
|
proc = subprocess.Popen(cmd, shell=False,
|
|
stdin=subprocess.PIPE,
|
|
stdout=subprocess.PIPE,
|
|
stderr=subprocess.PIPE)
|
|
(stdout, stderr) = proc.communicate()
|
|
return proc.returncode, stdout, stderr
|
|
else:
|
|
raise RunExternalScriptError('%s not executable' % script)
|
|
|