Files
munki/code/client/munkilib/keychain.py

571 lines
21 KiB
Python

#!/usr/bin/python
# encoding: utf-8
#
# Copyright 2014-2016 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
#
# https://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.
"""
keychain
Created by Greg Neagle on 2014-06-09.
Incorporating work and ideas from Michael Lynn here:
https://gist.github.com/pudquick/7704254
and here:
https://gist.github.com/pudquick/836a19b5ff17c5b7640d#file-cert_tricks-py
"""
import base64
import hashlib
import os
import subprocess
import munkicommon
# we use lots of camelCase-style names. Deal with it.
# pylint: disable=C0103
DEFAULT_KEYCHAIN_NAME = 'munki.keychain'
DEFAULT_KEYCHAIN_PASSWORD = 'munki'
KEYCHAIN_DIRECTORY = os.path.join(
munkicommon.pref('ManagedInstallDir'), 'Keychains')
def read_file(pathname):
'''Return the contents of pathname as a string'''
try:
fileobj = open(pathname, mode='r')
data = fileobj.read()
fileobj.close()
return data
except (OSError, IOError), err:
munkicommon.display_error(
'Could not read %s: %s', pathname, err)
return ''
def write_file(stringdata, pathname):
'''Writes stringdata to pathname.
Returns the pathname on success, empty string on failure.'''
try:
fileobject = open(pathname, mode='w')
fileobject.write(stringdata)
fileobject.close()
return pathname
except (OSError, IOError), err:
munkicommon.display_error('Couldn\'t write %s to %s: %s',
stringdata, pathname, err)
return ''
def pem_cert_bytes(cert_path):
'''Read in a base64 pem file, return raw bytestring of embedded
certificate'''
cert_data = read_file(cert_path)
if not (('-----BEGIN CERTIFICATE-----' in cert_data) and
('-----END CERTIFICATE-----' in cert_data)):
raise Exception('Certificate does not appear to be .pem file')
core_data = cert_data.split(
'-----BEGIN CERTIFICATE', 1)[-1].replace('\r', '\n').split(
'-----\n', 1)[-1].split('\n-----END CERTIFICATE-----', 1)[0]
return base64.b64decode(''.join(core_data.split('\n')))
def pem_cert_sha1_digest(cert_path):
'''Return SHA1 digest for pem certificate at path'''
try:
raw_bytes = pem_cert_bytes(cert_path)
return hashlib.sha1(raw_bytes).hexdigest().upper()
except BaseException, err:
munkicommon.display_error('Error reading %s: %s' % (cert_path, err))
return None
def get_munki_server_cert_info():
'''Attempt to get information we need from Munki's preferences or
defaults. Returns a dictionary.'''
ManagedInstallDir = munkicommon.pref('ManagedInstallDir')
cert_info = {}
# get server CA cert if it exists so we can verify the Munki server
cert_info['ca_cert_path'] = None
cert_info['ca_dir_path'] = None
if munkicommon.pref('SoftwareRepoCAPath'):
CA_path = munkicommon.pref('SoftwareRepoCAPath')
if os.path.isfile(CA_path):
cert_info['ca_cert_path'] = CA_path
elif os.path.isdir(CA_path):
cert_info['ca_dir_path'] = CA_path
if munkicommon.pref('SoftwareRepoCACertificate'):
cert_info['ca_cert_path'] = munkicommon.pref(
'SoftwareRepoCACertificate')
if cert_info['ca_cert_path'] == None:
ca_cert_path = os.path.join(ManagedInstallDir, 'certs', 'ca.pem')
if os.path.exists(ca_cert_path):
cert_info['ca_cert_path'] = ca_cert_path
return cert_info
def get_munki_client_cert_info():
'''Attempt to get information we need from Munki's preferences or
defaults. Returns a dictionary.'''
ManagedInstallDir = munkicommon.pref('ManagedInstallDir')
cert_info = {}
cert_info['client_cert_path'] = None
cert_info['client_key_path'] = None
cert_info['site_urls'] = []
# get client cert if it exists
if munkicommon.pref('UseClientCertificate'):
cert_info['client_cert_path'] = (
munkicommon.pref('ClientCertificatePath') or None)
cert_info['client_key_path'] = munkicommon.pref('ClientKeyPath') or None
if not cert_info['client_cert_path']:
for name in ['cert.pem', 'client.pem', 'munki.pem']:
client_cert_path = os.path.join(
ManagedInstallDir, 'certs', name)
if os.path.exists(client_cert_path):
cert_info['client_cert_path'] = client_cert_path
break
site_urls = []
for key in ['SoftwareRepoURL', 'PackageURL', 'CatalogURL',
'ManifestURL', 'IconURL', 'ClientResourceURL']:
url = munkicommon.pref(key)
if url:
site_urls.append(url.rstrip('/') + '/')
cert_info['site_urls'] = site_urls
return cert_info
def add_ca_certs_to_system_keychain(cert_info=None):
'''Adds any CA certs as trusted root certs to System.keychain'''
if not cert_info:
cert_info = get_munki_server_cert_info()
ca_cert_path = cert_info['ca_cert_path']
ca_dir_path = cert_info['ca_dir_path']
if not ca_cert_path and not ca_dir_path:
# no CA certs, so nothing to do
munkicommon.display_debug2(
'No CA cert info provided, so nothing to add to System keychain.')
return
else:
munkicommon.display_debug2('CA cert path: %s', ca_cert_path)
munkicommon.display_debug2('CA dir path: %s', ca_dir_path)
SYSTEM_KEYCHAIN = "/Library/Keychains/System.keychain"
if not os.path.exists(SYSTEM_KEYCHAIN):
munkicommon.display_warning('%s not found.', SYSTEM_KEYCHAIN)
return
# Add CA certs. security add-trusted-cert does the right thing even if
# the cert is already added, so we just do it; checking to see if the
# cert is already added is hard.
certs_to_add = []
if ca_cert_path:
certs_to_add.append(ca_cert_path)
if ca_dir_path:
# add any pem files in the ca_dir_path directory
for item in os.listdir(ca_dir_path):
if item.endswith('.pem'):
certs_to_add.append(os.path.join(ca_dir_path, item))
for cert in certs_to_add:
munkicommon.display_debug1('Adding CA cert %s...', cert)
try:
output = security('add-trusted-cert', '-d',
'-k', SYSTEM_KEYCHAIN, cert)
if output:
munkicommon.display_debug2(output)
except SecurityError, err:
munkicommon.display_error(
'Could not add CA cert %s into System keychain: %s', cert, err)
munkicommon.display_detail('System.keychain updated.')
def make_client_keychain(cert_info=None):
'''Builds a client cert keychain from existing client certs'''
if not cert_info:
# just grab data from Munki's preferences/defaults
cert_info = get_munki_client_cert_info()
client_cert_path = cert_info['client_cert_path']
client_key_path = cert_info['client_key_path']
site_urls = cert_info['site_urls']
if not client_cert_path:
# no client, so nothing to do
munkicommon.display_debug1(
'No client cert info provided, '
'so no client keychain will be created.')
return
else:
munkicommon.display_debug1('Client cert path: %s', client_cert_path)
munkicommon.display_debug1('Client key path: %s', client_key_path)
# to do some of the following options correctly, we need to be root
# and have root's home.
# check to see if we're root
if os.geteuid() != 0:
munkicommon.display_error(
'Can\'t make our client keychain unless we are root!')
return
# switch HOME if needed to root's home
original_home = os.environ.get('HOME')
if original_home:
os.environ['HOME'] = os.path.expanduser('~root')
keychain_pass = (
munkicommon.pref('KeychainPassword') or DEFAULT_KEYCHAIN_PASSWORD)
abs_keychain_path = get_keychain_path()
if os.path.exists(abs_keychain_path):
os.unlink(abs_keychain_path)
if not os.path.exists(os.path.dirname(abs_keychain_path)):
os.makedirs(os.path.dirname(abs_keychain_path))
# create a new keychain
munkicommon.display_debug1('Creating client keychain...')
try:
output = security('create-keychain',
'-p', keychain_pass, abs_keychain_path)
if output:
munkicommon.display_debug2(output)
except SecurityError, err:
munkicommon.display_error(
'Could not create keychain %s: %s', abs_keychain_path, err)
if original_home:
# switch it back
os.environ['HOME'] = original_home
return
# Ensure the keychain is in the search path and unlocked
added_keychain = add_to_keychain_list(abs_keychain_path)
unlock_and_set_nonlocking(abs_keychain_path)
# Add client cert (and optionally key)
client_cert_file = None
combined_pem = None
if client_key_path:
# combine client cert and private key before we import
cert_data = read_file(client_cert_path)
key_data = read_file(client_key_path)
# write the combined data
combined_pem = os.path.join(munkicommon.tmpdir(), 'combined.pem')
if write_file(cert_data + key_data, combined_pem):
client_cert_file = combined_pem
else:
munkicommon.display_error(
'Could not combine client cert and key for import!')
else:
client_cert_file = client_cert_path
if client_cert_file:
# client_cert_file is combined_pem or client_cert_file
munkicommon.display_debug2('Importing client cert and key...')
try:
output = security(
'import', client_cert_file, '-A', '-k', abs_keychain_path)
if output:
munkicommon.display_debug2(output)
except SecurityError, err:
munkicommon.display_error(
'Could not import %s: %s', client_cert_file, err)
if combined_pem:
# we created this; we should clean it up
try:
os.unlink(combined_pem)
except (OSError, IOError):
pass
id_hash = pem_cert_sha1_digest(client_cert_path)
if not id_hash:
munkicommon.display_error(
'Cannot create keychain identity preference.')
else:
# set up identity preference(s) linking the identity (cert and key)
# to the various urls
munkicommon.display_debug1('Creating identity preferences...')
try:
output = security('default-keychain')
if output:
munkicommon.display_debug2(output)
# One is defined, remember the path
default_keychain = [
x.strip().strip('"')
for x in output.split('\n') if x.strip()][0]
except SecurityError, err:
# error raised if there is no default
default_keychain = None
# Temporarily assign the default keychain to ours
try:
output = security(
'default-keychain', '-s', abs_keychain_path)
if output:
munkicommon.display_debug2(output)
except SecurityError, err:
munkicommon.display_error(
'Could not set default keychain to %s failed: %s'
% (abs_keychain_path, err))
default_keychain = None
# Create the identity preferences
for url in site_urls:
try:
munkicommon.display_debug2(
'Adding identity preference for %s...' % url)
output = security(
'set-identity-preference',
'-s', url, '-Z', id_hash, abs_keychain_path)
if output:
munkicommon.display_debug2(output)
except SecurityError, err:
munkicommon.display_error(
'Setting identity preference for %s failed: %s'
% (url, err))
if default_keychain:
# We originally had a different default, set it back
output = security(
'default-keychain', '-s', default_keychain)
if output:
munkicommon.display_debug2(output)
# we're done, clean up.
if added_keychain:
remove_from_keychain_list(abs_keychain_path)
if original_home:
# switch it back
os.environ['HOME'] = original_home
munkicommon.display_info(
'Completed creation of client keychain at %s' % abs_keychain_path)
def add_to_keychain_list(keychain_path):
'''Ensure the keychain is in the search path. Returns True if we
added the keychain to the list.'''
# we use *foo to expand a list of keychain paths
# pylint: disable=W0142
added_keychain = False
output = security('list-keychains', '-d', 'user')
# Split the output and strip it of whitespace and leading/trailing
# quotes, the result are absolute paths to keychains
# Preserve the order in case we need to append to them
search_keychains = [x.strip().strip('"')
for x in output.split('\n') if x.strip()]
if not keychain_path in search_keychains:
# Keychain is not in the search paths
munkicommon.display_debug2('Adding client keychain to search path...')
search_keychains.append(keychain_path)
try:
output = security(
'list-keychains', '-d', 'user', '-s', *search_keychains)
if output:
munkicommon.display_debug2(output)
added_keychain = True
except SecurityError, err:
munkicommon.display_error(
'Could not add keychain %s to keychain list: %s',
keychain_path, err)
added_keychain = False
return added_keychain
def remove_from_keychain_list(keychain_path):
'''Remove keychain from the list of keychains'''
# we use *foo to expand a list of keychain paths
# pylint: disable=W0142
output = security('list-keychains', '-d', 'user')
# Split the output and strip it of whitespace and leading/trailing
# quotes, the result are absolute paths to keychains
# Preserve the order in case we need to append to them
search_keychains = [x.strip().strip('"')
for x in output.split('\n') if x.strip()]
if keychain_path in search_keychains:
# Keychain is in the search path
munkicommon.display_debug1(
'Removing %s from search path...', keychain_path)
filtered_keychains = [keychain for keychain in search_keychains
if keychain != keychain_path]
try:
output = security(
'list-keychains', '-d', 'user', '-s', *filtered_keychains)
if output:
munkicommon.display_debug2(output)
except SecurityError, err:
munkicommon.display_error(
'Could not set new keychain list: %s', err)
def unlock_and_set_nonlocking(keychain_path):
'''Unlocks the keychain and sets it to non-locking'''
keychain_pass = (
munkicommon.pref('KeychainPassword') or DEFAULT_KEYCHAIN_PASSWORD)
try:
output = security(
'unlock-keychain', '-p', keychain_pass, keychain_path)
if output:
munkicommon.display_debug2(output)
except SecurityError, err:
# some problem unlocking the keychain.
munkicommon.display_error(
'Could not unlock %s: %s.', keychain_path, err)
# delete it
try:
os.unlink(keychain_path)
except OSError, err:
munkicommon.display_error(
'Could not remove %s: %s.', keychain_path, err)
return
try:
output = security('set-keychain-settings', keychain_path)
if output:
munkicommon.display_debug2(output)
except SecurityError, err:
munkicommon.display_error(
'Could not set keychain settings for %s: %s',
keychain_path, err)
def client_certs_exist():
'''Returns True if there a client cert exists
that we need to import into a keychain'''
cert_info = get_munki_client_cert_info()
client_cert_path = cert_info['client_cert_path']
# we must have a client cert; we don't at this stage need
# to check for a key
if client_cert_path and os.path.exists(client_cert_path):
return True
else:
return False
def client_certs_newer_than_keychain():
'''Returns True if we have client certs that are newer than our
client keychain, False otherwise'''
cert_info = get_munki_client_cert_info()
client_cert_path = cert_info['client_cert_path']
client_key_path = cert_info['client_key_path']
keychain_path = get_keychain_path()
if not client_cert_path or not os.path.exists(client_cert_path):
return False
if not os.path.exists(keychain_path):
return False
keychain_mod_time = os.stat(keychain_path).st_mtime
if os.stat(client_cert_path).st_mtime > keychain_mod_time:
return True
if client_key_path and os.path.exists(client_key_path):
if os.stat(client_key_path).st_mtime > keychain_mod_time:
return True
return False
def debug_output():
'''Debugging output for keychain'''
try:
munkicommon.display_debug1('***Keychain list***')
munkicommon.display_debug1(security('list-keychains', '-d', 'user'))
munkicommon.display_debug1('***Default keychain info***')
munkicommon.display_debug1(security('default-keychain', '-d', 'user'))
keychainfile = get_keychain_path()
if os.path.exists(keychainfile):
munkicommon.display_debug1('***Info for %s***' % keychainfile)
munkicommon.display_debug1(
security('show-keychain-info', keychainfile))
except SecurityError, err:
munkicommon.display_error(unicode(err))
class SecurityError(Exception):
'''An exception class to raise if there is an error running
/usr/bin/security'''
pass
def security(verb_name, *args):
'''Runs the security binary with args. Returns stdout.
Raises SecurityError for a non-zero return code'''
cmd = ['/usr/bin/security', verb_name] + list(args)
proc = subprocess.Popen(
cmd, shell=False, bufsize=-1,
stdout=subprocess.PIPE, stderr=subprocess.PIPE)
(output, err) = proc.communicate()
if proc.returncode:
raise SecurityError('%s: %s' % (proc.returncode, err))
return output or err
def get_keychain_path():
'''Returns an absolute path for our keychain'''
keychain_name = (
munkicommon.pref('KeychainName') or DEFAULT_KEYCHAIN_NAME)
# If we have an odd path that appears to be all directory and no
# file name, revert to default filename
if not os.path.basename(keychain_name):
keychain_name = DEFAULT_KEYCHAIN_NAME
# Check to make sure it's just a simple file name, no directory
# information
if os.path.dirname(keychain_name):
# keychain name should be just the filename,
# so we'll drop down to the base name
keychain_name = os.path.basename(
keychain_name).strip() or DEFAULT_KEYCHAIN_NAME
# Correct the filename to include '.keychain' if not already present
if not keychain_name.lower().endswith('.keychain'):
keychain_name += '.keychain'
keychain_path = os.path.realpath(
os.path.join(KEYCHAIN_DIRECTORY, keychain_name))
return keychain_path
class MunkiKeychain(object):
'''Wrapper class for handling the client keychain'''
keychain_path = None
added_keychain = False
def __init__(self):
'''Adds CA certs as trusted to System keychain.
Unlocks the munki.keychain if it exists.
Makes sure the munki.keychain is in the search list.
Creates a new client keychain if needed.'''
add_ca_certs_to_system_keychain()
self.keychain_path = get_keychain_path()
if client_certs_exist() and os.path.exists(self.keychain_path):
# we have client certs; we should build a keychain using them
try:
os.unlink(self.keychain_path)
except (OSError, IOError), err:
munkicommon.display_error(
'Could not remove pre-existing %s: %s'
% (self.keychain_path, err))
if os.path.exists(self.keychain_path):
# ensure existing keychain is available for use
self.added_keychain = add_to_keychain_list(self.keychain_path)
unlock_and_set_nonlocking(self.keychain_path)
if not os.path.exists(self.keychain_path):
# try making a new keychain
make_client_keychain()
if os.path.exists(self.keychain_path):
self.added_keychain = add_to_keychain_list(self.keychain_path)
unlock_and_set_nonlocking(self.keychain_path)
if not os.path.exists(self.keychain_path):
# give up
self.keychain_path = None
self.added_keychain = False
def __del__(self):
'''Remove our keychain from the keychain list if we added it'''
if self.added_keychain:
remove_from_keychain_list(self.keychain_path)