core-admin/qubespolicy/cli.py
2018-12-07 02:19:36 -05:00

145 lines
5.7 KiB
Python

# -*- encoding: utf8 -*-
#
# The Qubes OS Project, http://www.qubes-os.org
#
# Copyright (C) 2017 Marek Marczykowski-Górecki
# <marmarek@invisiblethingslab.com>
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library 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 this library; if not, see <https://www.gnu.org/licenses/>.
import argparse
import logging
import logging.handlers
import os
import sys
import qubespolicy
parser = argparse.ArgumentParser(description="Evaluate qrexec policy")
parser.add_argument("--assume-yes-for-ask", action="store_true",
dest="assume_yes_for_ask", default=False,
help="Allow run of service without confirmation if policy say 'ask'")
parser.add_argument("--just-evaluate", action="store_true",
dest="just_evaluate", default=False,
help="Do not run the service, only evaluate policy; "
"retcode=0 means 'allow'")
parser.add_argument('domain_id', metavar='src-domain-id',
help='Source domain ID (Xen ID or similar, not Qubes ID)')
parser.add_argument('domain', metavar='src-domain-name',
help='Source domain name')
parser.add_argument('target', metavar='dst-domain-name',
help='Target domain name')
parser.add_argument('service_name', metavar='service-name',
help='Service name')
parser.add_argument('process_ident', metavar='process-ident',
help='Qrexec process identifier - for connecting data channel')
def create_default_policy(service_name):
policy_file = os.path.join(qubespolicy.POLICY_DIR, service_name)
with open(policy_file, "w") as policy:
policy.write(
"## Policy file automatically created on first service call.\n")
policy.write(
"## Feel free to edit.\n")
policy.write("## Note that policy parsing stops at the first match\n")
policy.write("\n")
policy.write("## Please use a single # to start your custom comments\n")
policy.write("\n")
policy.write("@anyvm @anyvm ask\n")
def main(args=None):
args = parser.parse_args(args)
# Add source domain information, required by qrexec-client for establishing
# connection
caller_ident = args.process_ident + "," + args.domain + "," + args.domain_id
log = logging.getLogger('qubespolicy')
log.setLevel(logging.INFO)
if not log.handlers:
handler = logging.handlers.SysLogHandler(address='/dev/log')
log.addHandler(handler)
log_prefix = 'qrexec: {}: {} -> {}:'.format(
args.service_name, args.domain, args.target)
try:
system_info = qubespolicy.get_system_info()
except qubespolicy.QubesMgmtException as e:
log.error('%s error getting system info: %s', log_prefix, str(e))
return 1
try:
try:
policy = qubespolicy.Policy(args.service_name)
except qubespolicy.PolicyNotFound:
service_name = args.service_name.split('+')[0]
import pydbus
bus = pydbus.SystemBus()
proxy = bus.get('org.qubesos.PolicyAgent',
'/org/qubesos/PolicyAgent')
create_policy = proxy.ConfirmPolicyCreate(
args.domain, service_name)
if create_policy:
create_default_policy(service_name)
policy = qubespolicy.Policy(args.service_name)
else:
raise
action = policy.evaluate(system_info, args.domain, args.target)
if args.assume_yes_for_ask and action.action == qubespolicy.Action.ask:
action.action = qubespolicy.Action.allow
if args.just_evaluate:
return {
qubespolicy.Action.allow: 0,
qubespolicy.Action.deny: 1,
qubespolicy.Action.ask: 1,
}[action.action]
if action.action == qubespolicy.Action.ask:
# late import to save on time for allow/deny actions
import pydbus
bus = pydbus.SystemBus()
proxy = bus.get('org.qubesos.PolicyAgent',
'/org/qubesos/PolicyAgent')
icons = {name: system_info['domains'][name]['icon']
for name in system_info['domains'].keys()}
for dispvm_base in system_info['domains']:
if not (system_info['domains'][dispvm_base]
['template_for_dispvms']):
continue
dispvm_api_name = '@dispvm:' + dispvm_base
icons[dispvm_api_name] = \
system_info['domains'][dispvm_base]['icon']
icons[dispvm_api_name] = \
icons[dispvm_api_name].replace('app', 'disp')
response = proxy.Ask(args.domain, args.service_name,
action.targets_for_ask, action.target or '', icons)
if response:
action.handle_user_response(True, response)
else:
action.handle_user_response(False)
log.info('%s allowed to %s', log_prefix, str(action.target))
action.execute(caller_ident)
except qubespolicy.PolicySyntaxError as e:
log.error('%s error loading policy: %s', log_prefix, str(e))
return 1
except qubespolicy.AccessDenied as e:
log.info('%s denied: %s', log_prefix, str(e))
return 1
return 0
if __name__ == '__main__':
sys.exit(main())