1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
|
# -*- coding: utf-8 -*-
# privilege_policies.py
# Copyright (C) 2013 LEAP
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
"""
Helpers to determine if the needed policies for privilege escalation
are operative under this client run.
"""
import commands
import os
import subprocess
import psutil
import time
from twisted.logger import Logger
from twisted.python.procutils import which
from leap.bitmask.util import STANDALONE, here
from .constants import IS_LINUX
log = Logger()
# TODO wrap the install/uninstall helper functions around the policychecker
# classes below.
def install_helpers():
_helper_installer('install')
def uninstall_helpers():
_helper_installer('uninstall')
def _helper_installer(action):
if action not in ('install', 'uninstall'):
raise Exception('Wrong action: %s' % action)
if IS_LINUX:
cmd = 'bitmask_helpers ' + action
if STANDALONE:
binary_path = os.path.join(here(), "bitmask")
cmd = "%s %s" % (binary_path, cmd)
if os.getuid() != 0:
cmd = 'pkexec ' + cmd
retcode, output = commands.getstatusoutput(cmd)
if retcode != 0:
log.error('Error installing/uninstalling helpers: %s' % output)
log.error('Command was: %s' % cmd)
raise Exception('Could not install/install helpers')
else:
raise Exception('No install mechanism for this platform')
class NoPolkitAuthAgentAvailable(Exception):
message = 'No polkit authentication agent available. Please run one.'
class NoPkexecAvailable(Exception):
message = 'Could not find pkexec in the system'
class LinuxPolicyChecker(object):
"""
PolicyChecker for Linux
"""
LINUX_POLKIT_FILE = ("/usr/share/polkit-1/actions/"
"se.leap.bitmask.policy")
LINUX_POLKIT_FILE_BUNDLE = ("/usr/share/polkit-1/actions/"
"se.leap.bitmask.bundle.policy")
PKEXEC_BIN = 'pkexec'
@classmethod
def get_polkit_path(self):
"""
Returns the polkit file path.
:rtype: str
"""
return (self.LINUX_POLKIT_FILE_BUNDLE if STANDALONE
else self.LINUX_POLKIT_FILE)
@classmethod
def maybe_pkexec(self):
"""
Checks whether pkexec is available in the system, and
returns the path if found.
Might raise:
NoPkexecAvailable,
NoPolkitAuthAgentAvailable.
:returns: a list of the paths where pkexec is to be found
:rtype: list
"""
if not self._is_pkexec_in_system():
log.warn('System has no pkexec')
raise NoPkexecAvailable()
if not self.is_up():
self.launch()
seconds = 0
while not self.is_up():
if seconds >= 20:
log.warn('No polkit auth agent found. pkexec ' +
'will use its own auth agent.')
raise NoPolkitAuthAgentAvailable()
# XXX: sleep()!!!! we should do it the twisted way
time.sleep(1)
seconds += 1
pkexec_possibilities = which(self.PKEXEC_BIN)
if not pkexec_possibilities:
raise Exception("We couldn't find pkexec")
return pkexec_possibilities
@classmethod
def launch(self):
"""
Tries to launch polkit agent.
"""
if not self.is_up():
try:
# We need to quote the command because subprocess call
# will do "sh -c 'foo'", so if we do not quoute it we'll end
# up with a invocation to the python interpreter. And that
# is bad.
log.debug('Trying to launch polkit agent')
subprocess.call(
["python -m leap.bitmask.vpn.helpers.linux.polkit_agent"],
shell=True)
except Exception:
log.failure('Error while launching vpn')
@classmethod
def is_up(self):
"""
Checks if a polkit daemon is running.
:return: True if it's running, False if it's not.
:rtype: boolean
"""
# Note that gnome-shell does not uses a separate process for the
# polkit-agent, it uses a polkit-agent within its own process so we
# can't ps-grep a polkit process, we can ps-grep gnome-shell itself.
polkit_options = (
'polkit-gnome-authentication-agent-1',
'polkit-kde-authentication-agent-1',
'polkit-mate-authentication-agent-1',
'lxpolkit',
'lxsession',
'gnome-shell',
'fingerprint-polkit-agent',
'xfce-polkit',
)
is_running = False
for proc in psutil.process_iter():
if any((polkit in proc.name() for polkit in polkit_options)):
is_running = True
break
return is_running
@classmethod
def _is_pkexec_in_system(self):
"""
Checks the existence of the pkexec binary in system.
"""
pkexec_path = which('pkexec')
if len(pkexec_path) == 0:
return False
return True
|
