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authorKali Kaneko (leap communications) <kali@leap.se>2017-01-31 13:31:13 +0100
committerKali Kaneko (leap communications) <kali@leap.se>2017-02-23 00:37:25 +0100
commitca0e1c4518749e27bccad817d22ab87afbf8acf7 (patch)
tree636c1188683c1ea91d70b3aecd2810aafa7cf724 /src/leap/bitmask/vpn/privilege.py
parentff5ec25029db7669163854886be254fccde90e80 (diff)
[feature] initial port of legacy vpn code
non functional at the moment, but started doing some cleanup
Diffstat (limited to 'src/leap/bitmask/vpn/privilege.py')
-rw-r--r--src/leap/bitmask/vpn/privilege.py210
1 files changed, 210 insertions, 0 deletions
diff --git a/src/leap/bitmask/vpn/privilege.py b/src/leap/bitmask/vpn/privilege.py
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+# -*- 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 platform
+import time
+
+from abc import ABCMeta, abstractmethod
+
+from twisted.logger import Logger
+from twisted.python.procutils import which
+
+logger = Logger()
+
+
+flags_STANDALONE = False
+
+
+class NoPolkitAuthAgentAvailable(Exception):
+ pass
+
+
+class NoPkexecAvailable(Exception):
+ pass
+
+
+def is_missing_policy_permissions():
+ """
+ Returns True if we do not have implemented a policy checker for this
+ platform, or if the policy checker exists but it cannot find the
+ appropriate policy mechanisms in place.
+
+ :rtype: bool
+ """
+ _system = platform.system()
+ platform_checker = _system + "PolicyChecker"
+ policy_checker = globals().get(platform_checker, None)
+ if not policy_checker:
+ # it is true that we miss permission to escalate
+ # privileges without asking for password each time.
+ logger.debug("we could not find a policy checker implementation "
+ "for %s" % (_system,))
+ return True
+ return policy_checker().is_missing_policy_permissions()
+
+
+class PolicyChecker:
+ """
+ Abstract PolicyChecker class
+ """
+
+ __metaclass__ = ABCMeta
+
+ @abstractmethod
+ def is_missing_policy_permissions(self):
+ """
+ Returns True if we could not find any policy mechanisms that
+ are defined to be in used for this particular platform.
+
+ :rtype: bool
+ """
+ return True
+
+
+class LinuxPolicyChecker(PolicyChecker):
+ """
+ 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 flags_STANDALONE
+ else self.LINUX_POLKIT_FILE)
+
+ def is_missing_policy_permissions(self):
+ # FIXME this name is quite confusing, it does not have anything to do
+ # with file permissions.
+ """
+ Returns True if we could not find the appropriate policykit file
+ in place
+
+ :rtype: bool
+ """
+ path = self.get_polkit_path()
+ return not os.path.isfile(path)
+
+ @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 self._is_pkexec_in_system():
+ if not self.is_up():
+ self.launch()
+ time.sleep(2)
+ if self.is_up():
+ pkexec_possibilities = which(self.PKEXEC_BIN)
+ # leap_assert(len(pkexec_possibilities) > 0,
+ # "We couldn't find pkexec")
+ if not pkexec_possibilities:
+ logger.error("We couldn't find pkexec")
+ raise Exception("We couldn't find pkexec")
+ return pkexec_possibilities
+ else:
+ logger.warning("No polkit auth agent found. pkexec " +
+ "will use its own auth agent.")
+ raise NoPolkitAuthAgentAvailable()
+ else:
+ logger.warning("System has no pkexec")
+ raise NoPkexecAvailable()
+
+ @classmethod
+ def launch(self):
+ """
+ Tries to launch policykit
+ """
+ env = None
+ if flags_STANDALONE:
+ # This allows us to send to subprocess the environment configs that
+ # works for the standalone bundle (like the PYTHONPATH)
+ env = dict(os.environ)
+ # The LD_LIBRARY_PATH is set on the launcher but not forwarded to
+ # subprocess unless we do so explicitly.
+ env["LD_LIBRARY_PATH"] = os.path.abspath("./lib/")
+ 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.
+ logger.debug("Trying to launch polkit agent")
+ subprocess.call(["python -m leap.bitmask.util.polkit_agent"],
+ shell=True, env=env)
+ except Exception as exc:
+ logger.exception(exc)
+
+ @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.
+
+ # the [x] thing is to avoid grep match itself
+ polkit_options = [
+ 'ps aux | grep "polkit-[g]nome-authentication-agent-1"',
+ 'ps aux | grep "polkit-[k]de-authentication-agent-1"',
+ 'ps aux | grep "polkit-[m]ate-authentication-agent-1"',
+ 'ps aux | grep "[l]xpolkit"',
+ 'ps aux | grep "[l]xsession"',
+ 'ps aux | grep "[g]nome-shell"',
+ 'ps aux | grep "[f]ingerprint-polkit-agent"',
+ 'ps aux | grep "[x]fce-polkit"',
+ ]
+ is_running = [commands.getoutput(cmd) for cmd in polkit_options]
+
+ return any(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