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Committing per IRC discussions. Does not update the Makefile to install it yet.

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= How it works =
There are basically two modes:
 1. using an existing profile with --profile
 2. dynamically generating a profile

For '1', aa-sandbox is just a wrapper around aa-exec.

For '2', aa-sandbox leverages easyprof and allows you to specify policy
in a limited way on the command line. It then loads the policy into the
kernel as a profile (ie, 'profile <foo> { ... }') so it doesn't get in
the way of existing profiles. It currently calls apparmor_parser via
sudo or pkexec. Once the profile is loaded, aa-exec the application
under the profile.

When -X is specified, the application is launched inside its own X
server using either xpra (the default, which uses Xvfb), xephyr and
xpra3d (xpra, but using Xorg with the xdummy[1] driver for now[2].
xpra3d doesn't currently perform well, but works ok with newer Gnome
applications that now require GLX). When using '-X', it:
- adds an explicit deny rule for ~/.Xauthority
- generates a dynamic Xauthority file for the session in 
  ~/.Xauthority-sandbox<DISPLAYNUMBER>
- adds an allow rule for ~/.Xauthority-sandbox<DISPLAYNUMBER>
- adds checks for xhost being properly setup
- honors the --with-xauthority option which can be used with --profile

With the above, the :0.0 display should no longer be accessible. Eg:
$ ./aa-sandbox -t ~/sandbox-xterm -X /usr/bin/xterm
$ XAUTHORITY=~/.Xauthority DISPLAY=:0.0 xinput
No protocol specified
Unable to connect to X server

This requires a specifically configured xauth/xhost setup, which is less common
on modern distributions. The man page details how to get this setup.


= Trying it out =
Apply the patch, then:
$ cd ./utils
# cli
$ ./aa-sandbox --templates-dir=`pwd`/easyprof/templates --read-path=/proc/ /usr/bin/uptime

# 2d only
$ ./aa-sandbox --templates-dir=`pwd`/easyprof/templates -X /usr/bin/xeyes
$ ./aa-sandbox --templates-dir=`pwd`/easyprof/templates -X /usr/bin/gedit

# 2d alternate (xephyr)
$ ./aa-sandbox --templates-dir=`pwd`/easyprof/templates -X --with-xserver=xephyr /usr/bin/xeyes
$ ./aa-sandbox --templates-dir=`pwd`/easyprof/templates -X --with-xserver=xephyr /usr/bin/gedit

# 3d
$ ./aa-sandbox --templates-dir=`pwd`/easyprof/templates -X --with-xserver=xpra3d /usr/bin/xeyes
$ ./aa-sandbox --templates-dir=`pwd`/easyprof/templates -X --with-xserver=xpra3d /usr/bin/glxgears

# With an existing profile:
$ ./aa-sandbox --profile=/usr/bin/evolution -X --with-xserver=xpra3d /usr/bin/evolution


= The Patch =
The patch itself is pretty self contained:
utils/aa-easyprof:
- adjusted to import optparse

utils/easyprof/templates/sandbox*
- add two new templates to easyprof

utils/apparmor/easyprof.py:
- use 'profile <foo>' if '<foo>' is not an absolute path
- adjust parser handling so we can reuse it

utils/aa-sandbox:
- small script to drive utils/apparmor/sandbox.py

utils/apparmor/common.py:
- the start of our python library. aa-easyprof would eventually use 
  this (along with the various rewrites), but for now, only the 
  sandboxing uses it.

utils/apparmor/sandbox.py:
- the sandboxing code itself. Of particular note is the use of classing
  to support different X servers

utils/aa-sandbox.pod:
- the corresponding man page


= Improvements =
* don't use sudo
* make pulseaudio in xpra opt-in (currently it is off)
* take advantage of upstream's 3D patches when they stabilize
* investigate how applications can work with the Unity global menu
* surely lots more 

[1]http://xpra.org/Xdummy.html
[2]http://xpra.org/trac/ticket/147
This commit is contained in:
Jamie Strandboge 2013-01-14 09:11:58 -06:00
commit 3c41028cd5
9 changed files with 1173 additions and 49 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
.bzrignore
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@ -165,3 +165,4 @@ tests/regression/apparmor/unix_fd_server
tests/regression/apparmor/unlink
tests/regression/apparmor/xattrs
tests/regression/apparmor/coredump
./utils/apparmor/__pycache__

1
utils/aa-easyprof
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@ -11,6 +11,7 @@
import apparmor.easyprof
from apparmor.easyprof import AppArmorException, error
import optparse
import os
import sys

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utils/aa-sandbox Executable file
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@ -0,0 +1,37 @@
#! /usr/bin/env python
# ------------------------------------------------------------------
#
# Copyright (C) 2012 Canonical Ltd.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of version 2 of the GNU General Public
# License published by the Free Software Foundation.
#
# ------------------------------------------------------------------
import apparmor.sandbox
from apparmor.common import AppArmorException, error
import optparse
import os
import sys
if __name__ == "__main__":
argv = sys.argv
parser = optparse.OptionParser()
apparmor.easyprof.add_parser_policy_args(parser)
(opt, args) = apparmor.sandbox.parse_args(sys.argv, parser)
if len(args) < 1:
error("Must specify binary")
binary = args[0]
if not apparmor.sandbox.check_requirements(binary):
sys.exit(1)
if opt.withx:
rc, report = apparmor.sandbox.run_xsandbox(args, opt)
else:
rc, report = apparmor.sandbox.run_sandbox(args, opt)
apparmor.common.msg(report)
sys.exit(rc)

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utils/aa-sandbox.pod Normal file
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@ -0,0 +1,214 @@
# This publication is intellectual property of Canonical Ltd. Its contents
# can be duplicated, either in part or in whole, provided that a copyright
# label is visibly located on each copy.
#
# All information found in this book has been compiled with utmost
# attention to detail. However, this does not guarantee complete accuracy.
# Neither Canonical Ltd, the authors, nor the translators shall be held
# liable for possible errors or the consequences thereof.
#
# Many of the software and hardware descriptions cited in this book
# are registered trademarks. All trade names are subject to copyright
# restrictions and may be registered trade marks. Canonical Ltd
# essentially adheres to the manufacturer's spelling.
#
# Names of products and trademarks appearing in this book (with or without
# specific notation) are likewise subject to trademark and trade protection
# laws and may thus fall under copyright restrictions.
#
=pod
=head1 NAME
aa-sandbox - AppArmor sandboxing
=head1 SYNOPSIS
B<aa-sandbox> [option] <path to binary>
=head1 DESCRIPTION
B<aa-sandbox> provides a mechanism for sandboxing an application using an
existing profile or via dynamic profile generation. Please note that while this
tool can help with quickly confining an application, its utility is dependent on
the quality of the templates, policy groups and abstractions used. Also, this
tool may create policy which is less restrictive than creating policy by hand or
with B<aa-genprof> and B<aa-logprof>.
=head1 OPTIONS
B<aa-sandbox> accepts the following arguments:
=over 4
=item -t TEMPLATE, --template=TEMPLATE
Specify the template used to generate a profile. May specify either a system
template or a filename for the template to use. If not specified, uses
B<sandbox> or B<sandbox-x> when B<-X> is specified. See aa-easyprof(8) for
details. Privileged access is required to load the dynamically generated
profile (B<aa-sandbox> will prompt for a password).
=item -p POLICYGROUPS, --policy-groups=POLICYGROUPS
Specify POLICYGROUPS as a comma-separated list of policy groups. See
aa-easyprof(8) for more information on POLICYGROUPS.
=item -a ABSTRACTIONS, --abstractions=ABSTRACTIONS
Specify ABSTRACTIONS as a comma-separated list of AppArmor abstractions.
AppArmor abstractions are located in /etc/apparmor.d/abstractions. See
apparmor.d(5) for details.
=item -r PATH, --read-path=PATH
Specify a PATH to allow reads. May be specified multiple times. If the PATH
ends in a '/', then PATH is treated as a directory and reads are allowed to all
files under this directory. Can optionally use '/*' at the end of the PATH to
only allow reads to files directly in PATH.
=item -w PATH, --write-dir=PATH
Like --read-path but also allow writes in addition to reads.
=item --profile=PROFILE
Instead of generating a dynamic profile, specify an existing, loaded profile.
This does not require privileged access.
=item -X, --with-x
Run the sandboxed application in an isolated X server.
=item --with-xauthority=XAUTHORITY
Specify an Xauthority file to use rather than a dynamically generated one. This
is particularly useful in combination with --profile. This option must be used
with care to not allow too much access to the sandboxed application. In
particular, the profile specified with --profile must add a rule to deny access
to ~/.Xauthority for X sandboxing to be effective. Eg:
=over
audit deny @{HOME}/.Xauthority mrwlk,
=back
=item --with-xserver=XSERVER
Choose the nested XSERVER to use. Supported servers are: B<xpra> (the default),
B<xpra3d> and B<xephyr>. xpra uses the Xvfb(1) virtual framebuffer X server
while xpra3d uses the Xorg(1) server with the Xdummy (dummy_drv.so) driver.
=item --with-clipboard
Allow access to the clipboard when using B<xpra> or B<xpra3d>.
=item --with-xephyr-geometry=GEOMETRY
The starting geometry for the Xephyr(1) server to use.
=back
=head1 EXAMPLES
Use the existing system profile 'firefox' to sandbox /usr/bin/firefox:
=over
$ aa-sandbox -X --profile=firefox /usr/bin/firefox
=back
Sandbox xeyes:
=over
$ aa-sandbox -X /usr/bin/xeyes
=back
Sandbox glxgears:
=over
$ aa-sandbox -X --with-xserver=xpra3d /usr/bin/glxgears
=back
Sandbox uptime:
=over
$ aa-sandbox --read-path="/proc/*" /usr/bin/uptime
=back
=head1 NOTES
B<aa-sandbox> currently relies on Xsecurity rules based on Xauthority. As such,
xhost access controls need to be enabled and server interpreted values for
localuser must be removed. One way of achieving this is adding a late running
Xsession(5) script of the form:
=over
# Create an Xauthority file if it doesn't exist
[ ! -f "$HOME/.Xauthority" ] && [ -x /usr/bin/xauth ] &&
xauth generate :0 . trusted > /dev/null
# Default to the Xauthority file
[ -f "$HOME/.Xauthority" ] && [ -x /usr/bin/xhost ] && [ -x /usr/bin/id ] &&
xhost -si:localuser:`id -un` > /dev/null
=back
After adding the above, it is recommended you remove the existing ~/.Xauthority
file, then restart your session.
=head1 KNOWN LIMITATIONS
While B<aa-sandbox> may be useful in certain situations, there are a number
of limitations regarding both confinement and usability:
=over
As mentioned, the quality of the template or the specified profile directly
affects the application's confinement.
DBus system access is all or nothing and DBus session access is unconditionally
allowed.
No environment filtering is performed.
X server usage has not been fully audited (though simple attacks are believed
to be protected against when the system is properly setup. See B<NOTES>,
above).
Using a nested X server for each application is expensive.
Only the old X cursor is available with B<xpra> and B<xpra3d>.
The Ubuntu global menu is not currently supported. Gtk and Qt applications
should display the non-global menu by default, but applications like Firefox
and Thunderbird should be adjusted to disable the global menu.
Xpra does not handle screen resizing when hotplugging monitors gracefully.
Restarting the sandbox will resolve the issue.
=back
=head1 BUGS
If you find any bugs, please report them to Launchpad at
L<https://bugs.launchpad.net/apparmor/+filebug>.
=head1 SEE ALSO
apparmor(7) apparmor.d(5) aa-easyprof(8) Xorg(1) Xecurity(7) xpra(1) Xvfb(1)
Xephyr(1)
=cut

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utils/apparmor/common.py Normal file
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@ -0,0 +1,95 @@
# ------------------------------------------------------------------
#
# Copyright (C) 2012 Canonical Ltd.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of version 2 of the GNU General Public
# License published by the Free Software Foundation.
#
# ------------------------------------------------------------------
from __future__ import print_function
import subprocess
import sys
DEBUGGING = False
#
# Utility classes
#
class AppArmorException(Exception):
'''This class represents AppArmor exceptions'''
def __init__(self, value):
self.value = value
def __str__(self):
return repr(self.value)
#
# Utility functions
#
def error(out, exit_code=1, do_exit=True):
'''Print error message and exit'''
try:
print("ERROR: %s" % (out), file=sys.stderr)
except IOError:
pass
if do_exit:
sys.exit(exit_code)
def warn(out):
'''Print warning message'''
try:
print("WARN: %s" % (out), file=sys.stderr)
except IOError:
pass
def msg(out, output=sys.stdout):
'''Print message'''
try:
print("%s" % (out), file=output)
except IOError:
pass
def debug(out):
'''Print debug message'''
global DEBUGGING
if DEBUGGING:
try:
print("DEBUG: %s" % (out), file=sys.stderr)
except IOError:
pass
def cmd(command):
'''Try to execute the given command.'''
debug(command)
try:
sp = subprocess.Popen(command, stdout=subprocess.PIPE,
stderr=subprocess.STDOUT)
except OSError as ex:
return [127, str(ex)]
if sys.version_info[0] >= 3:
out = sp.communicate()[0].decode('ascii', 'ignore')
else:
out = sp.communicate()[0]
return [sp.returncode, out]
def cmd_pipe(command1, command2):
'''Try to pipe command1 into command2.'''
try:
sp1 = subprocess.Popen(command1, stdout=subprocess.PIPE)
sp2 = subprocess.Popen(command2, stdin=sp1.stdout)
except OSError as ex:
return [127, str(ex)]
if sys.version_info[0] >= 3:
out = sp2.communicate()[0].decode('ascii', 'ignore')
else:
out = sp2.communicate()[0]
return [sp2.returncode, out]

108
utils/apparmor/easyprof.py
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@ -202,9 +202,8 @@ def verify_policy(policy):
class AppArmorEasyProfile:
'''Easy profile class'''
def __init__(self, binary, opt):
self.conffile = "/etc/apparmor/easyprof.conf"
if opt.conffile:
self.conffile = os.path.abspath(opt.conffile)
opt.ensure_value("conffile", "/etc/apparmor/easyprof.conf")
self.conffile = os.path.abspath(opt.conffile)
self.dirs = dict()
if os.path.isfile(self.conffile):
@ -378,7 +377,10 @@ class AppArmorEasyProfile:
# Fill-in profile name and binary
policy = re.sub(r'###NAME###', name, policy)
policy = re.sub(r'###BINARY###', binary, policy)
if binary.startswith('/'):
policy = re.sub(r'###BINARY###', binary, policy)
else:
policy = re.sub(r'###BINARY###', "profile %s" % binary, policy)
# Fill-in various comment fields
if comment != None:
@ -456,51 +458,8 @@ def print_files(files):
with open(i) as f:
sys.stdout.write(f.read()+"\n")
def parse_args(args=None):
'''Parse arguments'''
global DEBUGGING
parser = optparse.OptionParser()
parser.add_option("-c", "--config-file",
dest="conffile",
help="Use alternate configuration file",
metavar="FILE")
parser.add_option("-d", "--debug",
help="Show debugging output",
action='store_true',
default=False)
parser.add_option("-t", "--template",
dest="template",
help="Use non-default policy template",
metavar="TEMPLATE",
default='default')
parser.add_option("--list-templates",
help="List available templates",
action='store_true',
default=False)
parser.add_option("--templates-dir",
dest="templates_dir",
help="Use non-default templates directory",
metavar="DIR")
parser.add_option("--show-template",
help="Show specified template",
action='store_true',
default=False)
parser.add_option("-p", "--policy-groups",
help="Comma-separated list of policy groups",
metavar="POLICYGROUPS")
parser.add_option("--list-policy-groups",
help="List available policy groups",
action='store_true',
default=False)
parser.add_option("--policy-groups-dir",
dest="policy_groups_dir",
help="Use non-default policy-groups directory",
metavar="DIR")
parser.add_option("--show-policy-group",
help="Show specified policy groups",
action='store_true',
default=False)
def add_parser_policy_args(parser):
'''Add parser arguments'''
parser.add_option("-a", "--abstractions",
dest="abstractions",
help="Comma-separated list of abstractions",
@ -515,6 +474,54 @@ def parse_args(args=None):
help="Path allowing owner writes",
metavar="PATH",
action="append")
parser.add_option("-t", "--template",
dest="template",
help="Use non-default policy template",
metavar="TEMPLATE",
default='default')
parser.add_option("--templates-dir",
dest="templates_dir",
help="Use non-default templates directory",
metavar="DIR")
parser.add_option("-p", "--policy-groups",
help="Comma-separated list of policy groups",
metavar="POLICYGROUPS")
parser.add_option("--policy-groups-dir",
dest="policy_groups_dir",
help="Use non-default policy-groups directory",
metavar="DIR")
def parse_args(args=None, parser=None):
'''Parse arguments'''
global DEBUGGING
if parser == None:
parser = optparse.OptionParser()
parser.add_option("-c", "--config-file",
dest="conffile",
help="Use alternate configuration file",
metavar="FILE")
parser.add_option("-d", "--debug",
help="Show debugging output",
action='store_true',
default=False)
parser.add_option("--list-templates",
help="List available templates",
action='store_true',
default=False)
parser.add_option("--show-template",
help="Show specified template",
action='store_true',
default=False)
parser.add_option("--list-policy-groups",
help="List available policy groups",
action='store_true',
default=False)
parser.add_option("--show-policy-group",
help="Show specified policy groups",
action='store_true',
default=False)
parser.add_option("-n", "--name",
dest="name",
help="Name of policy",
@ -537,6 +544,9 @@ def parse_args(args=None):
metavar="@{VARIABLE}=VALUE",
action="append")
# add policy args now
add_parser_policy_args(parser)
(my_opt, my_args) = parser.parse_args(args)
if my_opt.debug:
DEBUGGING = True

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utils/apparmor/sandbox.py Normal file
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@ -0,0 +1,691 @@
# ------------------------------------------------------------------
#
# Copyright (C) 2011-2012 Canonical Ltd.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of version 2 of the GNU General Public
# License published by the Free Software Foundation.
#
# ------------------------------------------------------------------
from apparmor.common import AppArmorException, debug, error, msg, cmd
import apparmor.easyprof
import optparse
import os
import pwd
import re
import signal
import sys
import tempfile
import time
def check_requirements(binary):
'''Verify necessary software is installed'''
exes = ['xset', # for detecting free X display
'aa-easyprof', # for templates
'aa-exec', # for changing profile
'sudo', # eventually get rid of this
'pkexec', # eventually get rid of this
binary]
for e in exes:
debug("Searching for '%s'" % e)
rc, report = cmd(['which', e])
if rc != 0:
error("Could not find '%s'" % e, do_exit=False)
return False
return True
def parse_args(args=None, parser=None):
'''Parse arguments'''
if parser == None:
parser = optparse.OptionParser()
parser.add_option('-X', '--with-x',
dest='withx',
default=False,
help='Run in isolated X server',
action='store_true')
parser.add_option('--with-xserver',
dest='xserver',
default='xpra',
help='Nested X server to use: xpra (default), xpra3d, xephyr')
parser.add_option('--with-clipboard',
dest='with_clipboard',
default=False,
help='Allow clipboard access',
action='store_true')
parser.add_option('--with-xauthority',
dest='xauthority',
default=None,
help='Specify Xauthority file to use')
parser.add_option('-d', '--debug',
dest='debug',
default=False,
help='Show debug messages',
action='store_true')
parser.add_option('--with-xephyr-geometry',
dest='xephyr_geometry',
default=None,
help='Geometry for Xephyr window')
parser.add_option('--profile',
dest='profile',
default=None,
help='Specify an existing profile (see aa-status)')
(my_opt, my_args) = parser.parse_args()
if my_opt.debug:
apparmor.common.DEBUGGING = True
valid_xservers = ['xpra', 'xpra3d', 'xephyr']
if my_opt.withx and my_opt.xserver.lower() not in valid_xservers:
error("Invalid server '%s'. Use one of: %s" % (my_opt.xserver, \
", ".join(valid_xservers)))
if my_opt.withx:
if my_opt.xephyr_geometry and my_opt.xserver.lower() != "xephyr":
error("Invalid option --with-xephyr-geometry with '%s'" % my_opt.xserver)
elif my_opt.with_clipboard and my_opt.xserver.lower() == "xephyr":
error("Clipboard not supported with '%s'" % my_opt.xserver)
if my_opt.template == "default":
if my_opt.withx:
my_opt.template = "sandbox-x"
else:
my_opt.template = "sandbox"
return (my_opt, my_args)
def gen_policy_name(binary):
'''Generate a temporary policy based on the binary name'''
return "sandbox-%s%s" % (pwd.getpwuid(os.geteuid())[0],
re.sub(r'/', '_', binary))
def set_environ(env):
keys = env.keys()
keys.sort()
for k in keys:
msg("Using: %s=%s" % (k, env[k]))
os.environ[k] = env[k]
def aa_exec(command, opt, environ={}, verify_rules=[]):
'''Execute binary under specified policy'''
if opt.profile != None:
policy_name = opt.profile
else:
opt.ensure_value("template_var", None)
opt.ensure_value("name", None)
opt.ensure_value("comment", None)
opt.ensure_value("author", None)
opt.ensure_value("copyright", None)
binary = command[0]
policy_name = gen_policy_name(binary)
easyp = apparmor.easyprof.AppArmorEasyProfile(binary, opt)
params = apparmor.easyprof.gen_policy_params(policy_name, opt)
policy = easyp.gen_policy(**params)
debug("\n%s" % policy)
tmp = tempfile.NamedTemporaryFile(prefix = '%s-' % policy_name)
if sys.version_info[0] >= 3:
tmp.write(bytes(policy, 'utf-8'))
else:
tmp.write(policy)
tmp.flush()
debug("using '%s' template" % opt.template)
# TODO: get rid of this
if opt.withx:
rc, report = cmd(['pkexec', 'apparmor_parser', '-r', '%s' % tmp.name])
else:
rc, report = cmd(['sudo', 'apparmor_parser', '-r', tmp.name])
if rc != 0:
raise AppArmorException("Could not load policy")
rc, report = cmd(['sudo', 'apparmor_parser', '-p', tmp.name])
if rc != 0:
raise AppArmorException("Could not dump policy")
# Make sure the dynamic profile has the appropriate line for X
for r in verify_rules:
found = False
for line in report.splitlines():
line = line.strip()
if r == line:
found = True
break
if not found:
raise AppArmorException("Could not find required rule: %s" % r)
set_environ(environ)
args = ['aa-exec', '-p', policy_name, '--'] + command
rc, report = cmd(args)
return rc, report
def run_sandbox(command, opt):
'''Run application'''
# aa-exec
rc, report = aa_exec(command, opt)
return rc, report
class SandboxXserver():
def __init__(self, title, geometry=None,
driver=None,
xauth=None,
clipboard=False):
self.geometry = geometry
self.title = title
self.pids = []
self.driver = driver
self.clipboard = clipboard
self.tempfiles = []
self.timeout = 5 # used by xauth and for server starts
# preserve our environment
self.old_environ = dict()
for env in ['DISPLAY', 'XAUTHORITY', 'UBUNTU_MENUPROXY',
'QT_X11_NO_NATIVE_MENUBAR', 'LIBOVERLAY_SCROLLBAR']:
if env in os.environ:
self.old_environ[env] = os.environ[env]
# prepare the new environment
self.display, self.xauth = self.find_free_x_display()
if xauth:
abs_xauth = os.path.expanduser(xauth)
if os.path.expanduser("~/.Xauthority") == abs_xauth:
raise AppArmorException("Trusted Xauthority file specified. Aborting")
self.xauth = abs_xauth
self.new_environ = dict()
self.new_environ['DISPLAY'] = self.display
self.new_environ['XAUTHORITY'] = self.xauth
# Disable the global menu for now
self.new_environ["UBUNTU_MENUPROXY"] = ""
self.new_environ["QT_X11_NO_NATIVE_MENUBAR"] = "1"
# Disable the overlay scrollbar for now-- they don't track correctly
self.new_environ["LIBOVERLAY_SCROLLBAR"] = "0"
def cleanup(self):
'''Cleanup our forked pids, reset the environment, etc'''
self.pids.reverse()
debug(self.pids)
for pid in self.pids:
# Kill server with TERM
debug("kill %d" % pid)
os.kill(pid, signal.SIGTERM)
for pid in self.pids:
# Shoot the server dead
debug("kill -9 %d" % pid)
os.kill(pid, signal.SIGKILL)
for t in self.tempfiles:
if os.path.exists(t):
os.unlink(t)
if os.path.exists(self.xauth):
os.unlink(self.xauth)
# Reset our environment
set_environ(self.old_environ)
def find_free_x_display(self):
'''Find a free X display'''
old_lang = None
if 'LANG' in os.environ:
old_lang = os.environ['LANG']
os.environ['LANG'] = 'C'
display = ""
current = self.old_environ["DISPLAY"]
for i in range(1,257): # TODO: this puts an artificial limit of 256
# sandboxed applications
tmp = ":%d" % i
os.environ["DISPLAY"] = tmp
rc, report = cmd(['xset', '-q'])
if rc != 0 and 'Invalid MIT-MAGIC-COOKIE-1' not in report:
display = tmp
break
if old_lang:
os.environ['LANG'] = old_lang
os.environ["DISPLAY"] = current
if display == "":
raise AppArmorException("Could not find available X display")
# Use dedicated .Xauthority file
xauth = os.path.join(os.path.expanduser('~'), \
'.Xauthority-sandbox%s' % display.split(':')[1])
return display, xauth
def generate_title(self):
return "(Sandbox%s) %s" % (self.display, self.title)
def verify_host_setup(self):
'''Make sure we have everything we need'''
old_lang = None
if 'LANG' in os.environ:
old_lang = os.environ['LANG']
os.environ['LANG'] = 'C'
rc, report = cmd(['xhost'])
if old_lang:
os.environ['LANG'] = old_lang
if rc != 0:
raise AppArmorException("'xhost' exited with error")
if 'access control enabled' not in report:
raise AppArmorException("Access control currently disabled. Please enable with 'xhost -'")
username = pwd.getpwuid(os.geteuid())[0]
if ':localuser:%s' % username in report:
raise AppArmorException("Access control allows '%s' full access. Please see 'man aa-sandbox' for details" % username)
def start(self):
'''Start a nested X server (need to override)'''
# clean up the old one
if os.path.exists(self.xauth):
os.unlink(self.xauth)
rc, cookie = cmd(['mcookie'])
if rc != 0:
raise AppArmorException("Could not generate magic cookie")
rc, out = cmd(['xauth', '-f', self.xauth, \
'add', \
self.display, \
'MIT-MAGIC-COOKIE-1', \
cookie.strip()])
if rc != 0:
raise AppArmorException("Could not generate '%s'" % self.display)
class SandboxXephyr(SandboxXserver):
def start(self):
for e in ['Xephyr', 'matchbox-window-manager']:
debug("Searching for '%s'" % e)
rc, report = cmd(['which', e])
if rc != 0:
raise AppArmorException("Could not find '%s'" % e)
'''Run any setup code'''
SandboxXserver.start(self)
'''Start a Xephyr server'''
listener_x = os.fork()
if listener_x == 0:
# TODO: break into config file? Which are needed?
x_exts = ['-extension', 'GLX',
'-extension', 'MIT-SHM',
'-extension', 'RENDER',
'-extension', 'SECURITY',
'-extension', 'DAMAGE'
]
# verify_these
x_extra_args = ['-host-cursor', # less secure?
'-fakexa', # for games? seems not needed
'-nodri', # more secure?
]
if not self.geometry:
self.geometry = "640x480"
x_args = ['-nolisten', 'tcp',
'-screen', self.geometry,
'-br', # black background
'-reset', # reset after last client exists
'-terminate', # terminate at server reset
'-title', self.generate_title(),
] + x_exts + x_extra_args
args = ['/usr/bin/Xephyr'] + x_args + [self.display]
debug(" ".join(args))
os.execv(args[0], args)
sys.exit(0)
self.pids.append(listener_x)
time.sleep(1) # FIXME: detect if running
# Next, start the window manager
sys.stdout.flush()
os.chdir(os.environ["HOME"])
listener_wm = os.fork()
if listener_wm == 0:
# update environment
set_environ(self.new_environ)
args = ['/usr/bin/matchbox-window-manager', '-use_titlebar', 'no']
debug(" ".join(args))
cmd(args)
sys.exit(0)
self.pids.append(listener_wm)
time.sleep(1) # FIXME: detect if running
class SandboxXpra(SandboxXserver):
def cleanup(self):
sys.stderr.flush()
listener = os.fork()
if listener == 0:
args = ['/usr/bin/xpra', 'stop', self.display]
debug(" ".join(args))
os.execv(args[0], args)
sys.exit(0)
time.sleep(2)
# Annoyingly, xpra doesn't clean up itself well if the application
# failed for some reason. Try to account for that.
rc, report = cmd(['ps', 'auxww'])
for line in report.splitlines():
if '-for-Xpra-%s' % self.display in line:
self.pids.append(int(line.split()[1]))
SandboxXserver.cleanup(self)
def _get_xvfb_args(self):
'''Setup xvfb arguments'''
# Debugging tip (can also use glxinfo):
# $ xdpyinfo > /tmp/native
# $ aa-sandbox -X -t sandbox-x /usr/bin/xdpyinfo > /tmp/nested
# $ diff -Naur /tmp/native /tmp/nested
xvfb_args = []
if self.driver == None:
# The default from the man page, but be explicit in what we enable
xvfb_args.append('--xvfb=Xvfb')
xvfb_args.append('-screen 0 3840x2560x24+32')
xvfb_args.append('-nolisten tcp')
xvfb_args.append('-noreset')
xvfb_args.append('-auth %s' % self.new_environ['XAUTHORITY'])
xvfb_args.append('+extension Composite')
xvfb_args.append('+extension SECURITY')
xvfb_args.append('-extension GLX')
elif self.driver == 'xdummy':
# The dummy driver allows us to use GLX, etc. See:
# http://xpra.org/Xdummy.html
conf = '''# /usr/share/doc/xpra/examples/dummy.xorg.conf.gz
# http://xpra.org/Xdummy.html
##Xdummy:##
Section "ServerFlags"
Option "DontVTSwitch" "true"
Option "AllowMouseOpenFail" "true"
Option "PciForceNone" "true"
Option "AutoEnableDevices" "false"
Option "AutoAddDevices" "false"
EndSection
##Xdummy:##
Section "InputDevice"
Identifier "NoMouse"
Option "CorePointer" "true"
Driver "void"
EndSection
Section "InputDevice"
Identifier "NoKeyboard"
Option "CoreKeyboard" "true"
Driver "void"
EndSection
##Xdummy:##
Section "Device"
Identifier "Videocard0"
Driver "dummy"
# In kByte
#VideoRam 4096000
#VideoRam 256000
# This should be good for 3840*2560*32bpp: http://winswitch.org/trac/ticket/140
VideoRam 64000
EndSection
##Xdummy:##
Section "Monitor"
Identifier "Monitor0"
HorizSync 10.0 - 300.0
VertRefresh 10.0 - 200.0
DisplaySize 4335 1084
#The following modeline is invalid (calculator overflowed):
#Modeline "32000x32000@0" -38917.43 32000 32032 -115848 -115816 32000 32775 32826 33601
Modeline "16384x8192@10" 2101.93 16384 16416 24400 24432 8192 8390 8403 8602
Modeline "8192x4096@10" 424.46 8192 8224 9832 9864 4096 4195 4202 4301
Modeline "5120x3200@10" 199.75 5120 5152 5904 5936 3200 3277 3283 3361
Modeline "3840x2880@10" 133.43 3840 3872 4376 4408 2880 2950 2955 3025
Modeline "3840x2560@10" 116.93 3840 3872 4312 4344 2560 2622 2627 2689
Modeline "3840x2048@10" 91.45 3840 3872 4216 4248 2048 2097 2101 2151
Modeline "2048x2048@10" 49.47 2048 2080 2264 2296 2048 2097 2101 2151
Modeline "2560x1600@10" 47.12 2560 2592 2768 2800 1600 1639 1642 1681
Modeline "1920x1200@10" 26.28 1920 1952 2048 2080 1200 1229 1231 1261
Modeline "1920x1080@10" 23.53 1920 1952 2040 2072 1080 1106 1108 1135
Modeline "1680x1050@10" 20.08 1680 1712 1784 1816 1050 1075 1077 1103
Modeline "1600x900@20" 33.92 1600 1632 1760 1792 900 921 924 946
Modeline "1440x900@20" 30.66 1440 1472 1584 1616 900 921 924 946
Modeline "1360x768@20" 24.49 1360 1392 1480 1512 768 786 789 807
#common resolutions for android devices (both orientations):
Modeline "800x1280@20" 25.89 800 832 928 960 1280 1310 1315 1345
Modeline "1280x800@20" 24.15 1280 1312 1400 1432 800 819 822 841
Modeline "720x1280@25" 30.22 720 752 864 896 1280 1309 1315 1345
Modeline "1280x720@25" 27.41 1280 1312 1416 1448 720 737 740 757
Modeline "768x1024@25" 24.93 768 800 888 920 1024 1047 1052 1076
Modeline "1024x768@25" 23.77 1024 1056 1144 1176 768 785 789 807
Modeline "600x1024@25" 19.90 600 632 704 736 1024 1047 1052 1076
Modeline "1024x600@25" 18.26 1024 1056 1120 1152 600 614 617 631
Modeline "536x960@25" 16.74 536 568 624 656 960 982 986 1009
Modeline "960x536@25" 15.23 960 992 1048 1080 536 548 551 563
Modeline "600x800@25" 15.17 600 632 688 720 800 818 822 841
Modeline "800x600@25" 14.50 800 832 880 912 600 614 617 631
Modeline "480x854@25" 13.34 480 512 560 592 854 873 877 897
Modeline "848x480@25" 12.09 848 880 920 952 480 491 493 505
Modeline "480x800@25" 12.43 480 512 552 584 800 818 822 841
Modeline "800x480@25" 11.46 800 832 872 904 480 491 493 505
Modeline "320x480@50" 10.73 320 352 392 424 480 490 494 505
Modeline "480x320@50" 9.79 480 512 544 576 320 327 330 337
Modeline "240x400@50" 6.96 240 272 296 328 400 408 412 421
Modeline "400x240@50" 6.17 400 432 448 480 240 245 247 253
Modeline "240x320@50" 5.47 240 272 288 320 320 327 330 337
Modeline "320x240@50" 5.10 320 352 368 400 240 245 247 253
#resolutions for android devices (both orientations)
#minus the status bar
#38px status bar (and width rounded up)
Modeline "800x1242@20" 25.03 800 832 920 952 1242 1271 1275 1305
Modeline "1280x762@20" 22.93 1280 1312 1392 1424 762 780 783 801
Modeline "720x1242@25" 29.20 720 752 856 888 1242 1271 1276 1305
Modeline "1280x682@25" 25.85 1280 1312 1408 1440 682 698 701 717
Modeline "768x986@25" 23.90 768 800 888 920 986 1009 1013 1036
Modeline "1024x730@25" 22.50 1024 1056 1136 1168 730 747 750 767
Modeline "600x986@25" 19.07 600 632 704 736 986 1009 1013 1036
Modeline "1024x562@25" 17.03 1024 1056 1120 1152 562 575 578 591
Modeline "536x922@25" 16.01 536 568 624 656 922 943 947 969
Modeline "960x498@25" 14.09 960 992 1040 1072 498 509 511 523
Modeline "600x762@25" 14.39 600 632 680 712 762 779 783 801
Modeline "800x562@25" 13.52 800 832 880 912 562 575 578 591
Modeline "480x810@25" 12.59 480 512 552 584 810 828 832 851
Modeline "848x442@25" 11.09 848 880 920 952 442 452 454 465
Modeline "480x762@25" 11.79 480 512 552 584 762 779 783 801
Modeline "800x442@25" 10.51 800 832 864 896 442 452 454 465
#32px status bar (no need for rounding):
Modeline "320x448@50" 9.93 320 352 384 416 448 457 461 471
Modeline "480x288@50" 8.75 480 512 544 576 288 294 297 303
#24px status bar:
Modeline "240x376@50" 6.49 240 272 296 328 376 384 387 395
Modeline "400x216@50" 5.50 400 432 448 480 216 220 222 227
Modeline "240x296@50" 5.02 240 272 288 320 296 302 305 311
Modeline "320x216@50" 4.55 320 352 368 400 216 220 222 227
EndSection
##Xdummy:##
Section "Screen"
Identifier "Screen0"
Device "Videocard0"
Monitor "Monitor0"
DefaultDepth 24
SubSection "Display"
Viewport 0 0
Depth 24
Modes "32000x32000" "16384x8192" "8192x4096" "5120x3200" "3840x2880" "3840x2560" "3840x2048" "2048x2048" "2560x1600" "1920x1440" "1920x1200" "1920x1080" "1600x1200" "1680x1050" "1600x900" "1400x1050" "1440x900" "1280x1024" "1366x768" "1280x800" "1024x768" "1024x600" "800x600" "320x200"
#Virtual 32000 32000
#Virtual 16384 8192
#Virtual 8192 4096
# http://winswitch.org/trac/ticket/140
Virtual 3840 2560
EndSubSection
EndSection
Section "ServerLayout"
Identifier "dummy_layout"
Screen "screen0"
InputDevice "NoMouse"
InputDevice "NoKeyboard"
EndSection
'''
tmp, xorg_conf = tempfile.mkstemp(prefix='aa-sandbox-xorg.conf-')
self.tempfiles.append(xorg_conf)
if sys.version_info[0] >= 3:
os.write(tmp, bytes(conf, 'utf-8'))
else:
os.write(tmp, conf)
os.close(tmp)
xvfb_args.append('--xvfb=Xorg')
xvfb_args.append('-dpi 96') # https://www.xpra.org/trac/ticket/163
xvfb_args.append('-nolisten tcp')
xvfb_args.append('-noreset')
xvfb_args.append('-logfile %s' % os.path.expanduser('~/.xpra/%s.log' % self.display))
xvfb_args.append('-auth %s' % self.new_environ['XAUTHORITY'])
xvfb_args.append('-config %s' % xorg_conf)
extensions = ['Composite', 'GLX', 'RANDR', 'RENDER', 'SECURITY']
for i in extensions:
xvfb_args.append('+extension %s' % i)
else:
raise AppArmorException("Unsupported X driver '%s'" % self.driver)
return xvfb_args
def start(self):
debug("Searching for '%s'" % 'xpra')
rc, report = cmd(['which', 'xpra'])
if rc != 0:
raise AppArmorException("Could not find '%s'" % 'xpra')
if self.driver == "xdummy":
# FIXME: is there a better way we can detect this?
drv = "/usr/lib/xorg/modules/drivers/dummy_drv.so"
debug("Searching for '%s'" % drv)
if not os.path.exists(drv):
raise AppArmorException("Could not find '%s'" % drv)
'''Run any setup code'''
SandboxXserver.start(self)
xvfb_args = self._get_xvfb_args()
listener_x = os.fork()
if listener_x == 0:
os.environ['XAUTHORITY'] = self.xauth
# This will clean out any dead sessions
cmd(['xpra', 'list'])
x_args = ['--no-daemon',
#'--no-mmap', # for security?
'--no-pulseaudio']
if not self.clipboard:
x_args.append('--no-clipboard')
if xvfb_args != '':
x_args.append(" ".join(xvfb_args))
args = ['/usr/bin/xpra', 'start', self.display] + x_args
debug(" ".join(args))
sys.stderr.flush()
os.execv(args[0], args)
sys.exit(0)
self.pids.append(listener_x)
started = False
time.sleep(0.5) # FIXME: detect if running
for i in range(self.timeout): # 5 seconds to start
rc, out = cmd(['xpra', 'list'])
if 'LIVE session at %s' % self.display in out:
started = True
break
time.sleep(1)
if not started:
sys.stdout.flush()
self.cleanup()
raise AppArmorException("Could not start xpra (try again with -d)")
# Next, attach to xpra
sys.stdout.flush()
os.chdir(os.environ["HOME"])
listener_attach = os.fork()
if listener_attach == 0:
args = ['/usr/bin/xpra', 'attach', self.display,
'--title=%s' % self.generate_title(),
#'--no-mmap', # for security?
'--no-tray',
'--no-pulseaudio']
if not self.clipboard:
args.append('--no-clipboard')
debug(" ".join(args))
sys.stderr.flush()
os.execv(args[0], args)
sys.exit(0)
self.pids.append(listener_attach)
msg("TODO: filter '~/.xpra/run-xpra'")
def run_xsandbox(command, opt):
'''Run X application in a sandbox'''
old_cwd = os.getcwd()
# first, start X
if opt.xserver.lower() == "xephyr":
x = SandboxXephyr(command[0], geometry=opt.xephyr_geometry,
xauth=opt.xauthority)
elif opt.xserver.lower() == "xpra3d":
x = SandboxXpra(command[0], geometry=None,
driver="xdummy",
xauth=opt.xauthority,
clipboard=opt.with_clipboard)
else:
x = SandboxXpra(command[0], geometry=None,
xauth=opt.xauthority,
clipboard=opt.with_clipboard)
x.verify_host_setup()
# Debug: show old environment
keys = x.old_environ.keys()
keys.sort()
for k in keys:
debug ("Old: %s=%s" % (k, x.old_environ[k]))
try:
x.start()
except Exception as e:
error(e)
if not opt.read_path:
opt.read_path = []
opt.read_path.append(x.xauth)
# Only used with dynamic profiles
required_rules = ['audit deny @{HOME}/.Xauthority mrwlk,']
# aa-exec
try:
rc, report = aa_exec(command, opt, x.new_environ, required_rules)
except Exception as e:
x.cleanup()
raise
x.cleanup()
os.chdir(old_cwd)
return rc, report

29
utils/easyprof/templates/sandbox Normal file
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@ -0,0 +1,29 @@
#
# Example usage for a program named 'foo' which is installed in /opt/foo
# $ aa-easyprof --template=sandbox \
# --template-var="@{APPNAME}=foo" \
# --policy-groups=opt-application,user-application \
# /opt/foo/bin/foo
#
###ENDUSAGE###
# vim:syntax=apparmor
# AppArmor policy for ###NAME###
#include <tunables/global>
###VAR###
###BINARY### {
#include <abstractions/base>
/ r,
/**/ r,
/usr/** r,
###ABSTRACTIONS###
###POLICYGROUPS###
###READS###
###WRITES###
}

46
utils/easyprof/templates/sandbox-x Normal file
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@ -0,0 +1,46 @@
#
# Example usage for a program named 'foo' which is installed in /opt/foo
# $ aa-easyprof --template=sandbox \
# --template-var="@{APPNAME}=foo" \
# --policy-groups=opt-application,user-application \
# /opt/foo/bin/foo
#
###ENDUSAGE###
# vim:syntax=apparmor
# AppArmor policy for ###NAME###
#include <tunables/global>
###VAR###
###BINARY### {
#include <abstractions/base>
#include <abstractions/gnome>
#include <abstractions/kde>
#include <abstractions/X>
audit deny @{HOME}/.Xauthority mrwlk,
/etc/passwd r,
/ r,
/**/ r,
/usr/** r,
/var/lib/dbus/machine-id r,
owner @{PROC}/[0-9]*/auxv r,
owner @{PROC}/[0-9]*/fd/ r,
owner @{PROC}/[0-9]*/environ r,
owner @{PROC}/[0-9]*/mounts r,
owner @{PROC}/[0-9]*/smaps r,
owner @{PROC}/[0-9]*/statm r,
owner @{PROC}/[0-9]*/task/[0-9]*/stat r,
###ABSTRACTIONS###
###POLICYGROUPS###
###READS###
###WRITES###
}