Merge remote-tracking branch 'ben-grande/clean'

This commit is contained in:
Patrick Schleizer 2024-01-16 08:19:28 -05:00
commit 862bf6b5ab
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GPG Key ID: CB8D50BB77BB3C48
26 changed files with 731 additions and 715 deletions

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@ -433,23 +433,23 @@ include but are not limited to:
- Protecting the information of sudoers from others.
- Protecting various system relevant files and modules.
##### permission-hardening #####
##### permission-hardener #####
`permission-hardener` removes SUID / SGID bits from non-essential binaries as
these are often used in privilege escalation attacks. It runs at package
installation and upgrade time.
There is also an optional systemd unit which does the same at boot time that
can be enabled by running `systemctl enable permission-hardening.service` as
can be enabled by running `systemctl enable permission-hardener.service` as
root. The hardening at boot time is not the default because this slows down
the boot too much.
See:
* `/usr/bin/permission-hardening`
* `/usr/bin/permission-hardener`
* `debian/security-misc.postinst`
* `/lib/systemd/system/permission-hardening.service`
* `/etc/permission-hardening.d`
* `/lib/systemd/system/permission-hardener.service`
* `/etc/permission-hardener.d`
* https://forums.whonix.org/t/disable-suid-binaries/7706
* https://www.kicksecure.com/wiki/SUID_Disabler_and_Permission_Hardener

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@ -20,8 +20,8 @@ permission_hardening() {
echo "Running SUID Disabler and Permission Hardener... See also:"
echo "https://www.kicksecure.com/wiki/SUID_Disabler_and_Permission_Hardener"
echo ""
echo "$0: INFO: running: permission-hardening"
if ! permission-hardening ; then
echo "$0: INFO: running: permission-hardener"
if ! permission-hardener ; then
echo "$0: ERROR: Permission hardening failed." >&2
return 0
fi
@ -59,7 +59,7 @@ esac
pam-auth-update --package
/usr/libexec/security-misc/permission-lockdown
permission_hardening
permission_hardener
## https://phabricator.whonix.org/T377
## Debian has no update-grub trigger yet:

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@ -1,8 +1,8 @@
## Copyright (C) 2012 - 2023 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Please use "/etc/permission-hardening.d/20_user.conf" or
## "/usr/local/etc/permission-hardening.d/20_user.conf" for your custom
## Please use "/etc/permission-hardener.d/20_user.conf" or
## "/usr/local/etc/permission-hardener.d/20_user.conf" for your custom
## configuration. When security-misc is updated, this file may be overwritten.
# Keep the `passwd` utility executable to prevent issues with the

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@ -1,8 +1,8 @@
## Copyright (C) 2012 - 2023 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Please use "/etc/permission-hardening.d/20_user.conf" or
## "/usr/local/etc/permission-hardening.d/20_user.conf" for your custom
## Please use "/etc/permission-hardener.d/20_user.conf" or
## "/usr/local/etc/permission-hardener.d/20_user.conf" for your custom
## configuration. When security-misc is updated, this file may be overwritten.
## https://forums.whonix.org/t/restrict-root-access/7658/116

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@ -1,8 +1,8 @@
## Copyright (C) 2012 - 2023 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Please use "/etc/permission-hardening.d/20_user.conf" or
## "/usr/local/etc/permission-hardening.d/20_user.conf" for your custom
## Please use "/etc/permission-hardener.d/20_user.conf" or
## "/usr/local/etc/permission-hardener.d/20_user.conf" for your custom
## configuration. When security-misc is updated, this file may be overwritten.
/usr/bin/bwrap exactwhitelist

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@ -1,8 +1,8 @@
## Copyright (C) 2012 - 2023 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Please use "/etc/permission-hardening.d/20_user.conf" or
## "/usr/local/etc/permission-hardening.d/20_user.conf" for your custom
## Please use "/etc/permission-hardener.d/20_user.conf" or
## "/usr/local/etc/permission-hardener.d/20_user.conf" for your custom
## configuration. When security-misc is updated, this file may be overwritten.
chrome-sandbox matchwhitelist

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@ -1,8 +1,8 @@
## Copyright (C) 2012 - 2023 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Please use "/etc/permission-hardening.d/20_user.conf" or
## "/usr/local/etc/permission-hardening.d/20_user.conf" for your custom
## Please use "/etc/permission-hardener.d/20_user.conf" or
## "/usr/local/etc/permission-hardener.d/20_user.conf" for your custom
## configuration. When security-misc is updated, this file may be overwritten.
dbus-daemon-launch-helper matchwhitelist

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@ -1,8 +1,8 @@
## Copyright (C) 2012 - 2023 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Please use "/etc/permission-hardening.d/20_user.conf" or
## "/usr/local/etc/permission-hardening.d/20_user.conf" for your custom
## Please use "/etc/permission-hardener.d/20_user.conf" or
## "/usr/local/etc/permission-hardener.d/20_user.conf" for your custom
## configuration. When security-misc is updated, this file may be overwritten.
## There is a controversy about firejail but those who choose to install it

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@ -1,8 +1,8 @@
## Copyright (C) 2012 - 2023 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Please use "/etc/permission-hardening.d/20_user.conf" or
## "/usr/local/etc/permission-hardening.d/20_user.conf" for your custom
## Please use "/etc/permission-hardener.d/20_user.conf" or
## "/usr/local/etc/permission-hardener.d/20_user.conf" for your custom
## configuration. When security-misc is updated, this file may be overwritten.
## required for AppImages such as electrum Bitcoin wallet

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@ -1,8 +1,8 @@
## Copyright (C) 2012 - 2023 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Please use "/etc/permission-hardening.d/20_user.conf" or
## "/usr/local/etc/permission-hardening.d/20_user.conf" for your custom
## Please use "/etc/permission-hardener.d/20_user.conf" or
## "/usr/local/etc/permission-hardener.d/20_user.conf" for your custom
## configuration. When security-misc is updated, this file may be overwritten.
libhardened_malloc.so matchwhitelist

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@ -1,8 +1,8 @@
## Copyright (C) 2012 - 2023 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Please use "/etc/permission-hardening.d/20_user.conf" or
## "/usr/local/etc/permission-hardening.d/20_user.conf" for your custom
## Please use "/etc/permission-hardener.d/20_user.conf" or
## "/usr/local/etc/permission-hardener.d/20_user.conf" for your custom
## configuration. When security-misc is updated, this file may be overwritten.
## https://forums.whonix.org/t/disable-suid-binaries/7706/61

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@ -1,8 +1,8 @@
## Copyright (C) 2012 - 2023 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Please use "/etc/permission-hardening.d/20_user.conf" or
## "/usr/local/etc/permission-hardening.d/20_user.conf" for your custom
## Please use "/etc/permission-hardener.d/20_user.conf" or
## "/usr/local/etc/permission-hardener.d/20_user.conf" for your custom
## configuration. When security-misc is updated, this file may be overwritten.
## Without this, Xfce fails to start with a dbus-launch error.

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@ -1,8 +1,8 @@
## Copyright (C) 2012 - 2023 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Please use "/etc/permission-hardening.d/20_user.conf" or
## "/usr/local/etc/permission-hardening.d/20_user.conf" for your custom
## Please use "/etc/permission-hardener.d/20_user.conf" or
## "/usr/local/etc/permission-hardener.d/20_user.conf" for your custom
## configuration. When security-misc is updated, this file may be overwritten.
/usr/bin/pkexec exactwhitelist

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@ -1,8 +1,8 @@
## Copyright (C) 2012 - 2023 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Please use "/etc/permission-hardening.d/20_user.conf" or
## "/usr/local/etc/permission-hardening.d/20_user.conf" for your custom
## Please use "/etc/permission-hardener.d/20_user.conf" or
## "/usr/local/etc/permission-hardener.d/20_user.conf" for your custom
## configuration. When security-misc is updated, this file may be overwritten.
## TODO: research

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@ -1,8 +1,8 @@
## Copyright (C) 2012 - 2023 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Please use "/etc/permission-hardening.d/20_user.conf" or
## "/usr/local/etc/permission-hardening.d/20_user.conf" for your custom
## Please use "/etc/permission-hardener.d/20_user.conf" or
## "/usr/local/etc/permission-hardener.d/20_user.conf" for your custom
## configuration. When security-misc is updated, this file may be overwritten.
/utempter/utempter matchwhitelist

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@ -1,8 +1,8 @@
## Copyright (C) 2012 - 2023 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Please use "/etc/permission-hardening.d/20_user.conf" or
## "/usr/local/etc/permission-hardening.d/20_user.conf" for your custom
## Please use "/etc/permission-hardener.d/20_user.conf" or
## "/usr/local/etc/permission-hardener.d/20_user.conf" for your custom
## configuration. When security-misc is updated, this file may be overwritten.
spice-client-glib-usb-acl-helper matchwhitelist

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@ -1,8 +1,8 @@
## Copyright (C) 2023 - 2023 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Please use "/etc/permission-hardening.d/20_user.conf" or
## "/usr/local/etc/permission-hardening.d/20_user.conf" for your custom
## Please use "/etc/permission-hardener.d/20_user.conf" or
## "/usr/local/etc/permission-hardener.d/20_user.conf" for your custom
## configuration. When security-misc is updated, this file may be overwritten.
## TODO: research

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@ -1,8 +1,8 @@
## Copyright (C) 2012 - 2023 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Please use "/etc/permission-hardening.d/20_user.conf" or
## "/usr/local/etc/permission-hardening.d/20_user.conf" for your custom
## Please use "/etc/permission-hardener.d/20_user.conf" or
## "/usr/local/etc/permission-hardener.d/20_user.conf" for your custom
## configuration. When security-misc is updated, this file may be overwritten.
/usr/bin/sudo exactwhitelist

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@ -1,8 +1,8 @@
## Copyright (C) 2012 - 2023 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Please use "/etc/permission-hardening.d/20_user.conf" or
## "/usr/local/etc/permission-hardening.d/20_user.conf" for your custom
## Please use "/etc/permission-hardener.d/20_user.conf" or
## "/usr/local/etc/permission-hardener.d/20_user.conf" for your custom
## configuration. When security-misc is updated, this file may be overwritten.
## required for performing password validation from unprivileged user

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@ -1,8 +1,8 @@
## Copyright (C) 2012 - 2023 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Please use "/etc/permission-hardening.d/20_user.conf" or
## "/usr/local/etc/permission-hardening.d/20_user.conf" for your custom
## Please use "/etc/permission-hardener.d/20_user.conf" or
## "/usr/local/etc/permission-hardener.d/20_user.conf" for your custom
## configuration. When security-misc is updated, this file may be overwritten.
## TODO: research

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@ -1,18 +1,16 @@
## Copyright (C) 2012 - 2023 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## Copyright (C) 2012 - 2024 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## Please use "/etc/permission-hardening.d/20_user.conf" or
## "/usr/local/etc/permission-hardening.d/20_user.conf" for your custom
## Please use "/etc/permission-hardener.d/20_user.conf" or
## "/usr/local/etc/permission-hardener.d/20_user.conf" for your custom
## configuration. When security-misc is updated, this file may be overwritten.
## File permission hardening.
##
## Syntax:
## [filename] [mode] [owner] [group] [capability]
## [filename] [exactwhitelist|matchwhitelist|disablewhitelist|nosuid]
##
## To remove all SUID/SGID binaries in a directory, you can use the "nosuid"
## argument.
## TODO: white spaces inside file name untested and probably will not work.
######################################################################
@ -22,13 +20,9 @@
#whitelists_disable_all=true
######################################################################
# SUID disablewhitelist
# SUID disables below (or in lexically higher) files: disablewhitelist
######################################################################
## disablewhitelist disables below (or in lexically higher) files
## exactwhitelist and matchwhitelist. Add these here (discouraged) or better
## in file "/etc/permission-hardening.d/20_user.conf".
## For example, if you are not using SELinux the following might make sense to
## enable. TODO: research
#/utempter/utempter disablewhitelist
@ -37,7 +31,7 @@
#/fusermount disablewhitelist
######################################################################
# SUID exact match whitelist
# SUID whitelist matches full path: exactwhitelist
######################################################################
## In case you need to use 'su'. See also:
@ -45,10 +39,6 @@
#/bin/su exactwhitelist
#/usr/bin/su exactwhitelist
######################################################################
# SUID exact match whitelist
######################################################################
## https://manpages.debian.org/xserver-xorg-legacy/Xorg.wrap.1.en.html
## https://lwn.net/Articles/590315/
## http://forums.whonix.org/t/permission-hardening/8655/25
@ -56,12 +46,12 @@
#/lib/xorg/Xorg.wrap whitelist
######################################################################
# SUID regex match whitelist
# SUID whitelist matches in any section of the path: matchwhitelist
######################################################################
######################################################################
# SUID regex match whitelist
######################################################################
## Examples below are already configured:
#ssh-agent matchwhitelist
#/lib/openssh matchwhitelist
######################################################################
# Permission Hardening
@ -70,8 +60,8 @@
/home/ 0755 root root
/root/ 0700 root root
/boot/ 0700 root root
/etc/permission-hardening.d 0600 root root
/usr/local/etc/permission-hardening.d 0600 root root
/etc/permission-hardener.d 0600 root root
/usr/local/etc/permission-hardener.d 0600 root root
/lib/modules/ 0700 root root
/usr/src 0700 root root
/etc/cups/cupsd.conf 0400 root root
@ -95,9 +85,12 @@
/etc/passwd- 0644 root root
######################################################################
# SUID/SGID Removal
# SUID/SGID Removal: nosuid
######################################################################
## To remove all SUID/SGID binaries in a directory, you can use the "nosuid"
## argument.
##
## Remove all SUID/SGID binaries/libraries.
/bin/ nosuid

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@ -5,7 +5,7 @@
disable hide-hardware-info.service
## Disable for now until development finished / tested.
disable permission-hardening.service
disable permission-hardener.service
## Disable for now until development finished / tested.
## https://github.com/Kicksecure/security-misc/pull/152

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@ -13,7 +13,7 @@ After=local-fs.target
[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=permission-hardening
ExecStart=permission-hardener
[Install]
WantedBy=sysinit.target

669
usr/bin/permission-hardener Executable file
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@ -0,0 +1,669 @@
#!/bin/bash
## Copyright (C) 2012 - 2024 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## https://forums.whonix.org/t/disable-suid-binaries/7706
## https://forums.whonix.org/t/re-mount-home-and-other-with-noexec-and-nosuid-among-other-useful-mount-options-for-better-security/7707
set -o errexit -o nounset -o pipefail
exit_code=0
store_dir="/var/lib/permission-hardener"
dpkg_admindir_parameter_existing_mode="--admindir ${store_dir}/existing_mode"
dpkg_admindir_parameter_new_mode="--admindir ${store_dir}/new_mode"
echo_wrapper_ignore() {
echo "INFO: run: $*"
"$@" 2>/dev/null || true
}
echo_wrapper_silent_ignore() {
#echo "INFO: run: $@"
"$@" 2>/dev/null || true
}
echo_wrapper_audit() {
echo "INFO: run: $*"
return_code=0
"$@" ||
{
return_code="$?"
exit_code=203
echo "ERROR: above command failed with exit code '${return_code}'! calling function name: '${FUNCNAME[1]}'" >&2
}
}
echo_wrapper_silent_audit() {
#echo "run (debugging): $@"
return_code=0
"$@" ||
{
return_code="$?"
exit_code=204
echo "ERROR: above command '$*' failed with exit code '${return_code}'! calling function name: '${FUNCNAME[1]}'" >&2
}
}
make_store_dir(){
mkdir --parents "${store_dir}/private"
mkdir --parents "${store_dir}/existing_mode"
mkdir --parents "${store_dir}/new_mode"
}
sanity_tests() {
echo_wrapper_silent_audit which \
capsh getcap setcap stat find dpkg-statoverride getent xargs grep 1>/dev/null
}
add_nosuid_statoverride_entry() {
local fso_to_process
fso_to_process="${fso}"
local should_be_counter
should_be_counter="$(find "${fso_to_process}" -perm /u=s,g=s | wc -l)" || true
local counter_actual
counter_actual=0
local line
while read -r line; do
true "line: ${line}"
counter_actual="$((counter_actual + 1))"
local arr file_name existing_mode existing_owner existing_group
IFS=" " read -r -a arr <<< "${line}"
file_name="${arr[0]}"
existing_mode="${arr[1]}"
existing_owner="${arr[2]}"
existing_group="${arr[3]}"
if test "${#arr[@]}" = 0; then
echo "ERROR: arr is empty. line: '${line}'" >&2
continue
fi
if test -z "${file_name}"; then
echo "ERROR: file_name is empty. line: '${line}'" >&2
continue
fi
if test -z "${existing_mode}"; then
echo "ERROR: existing_mode is empty. line: '${line}'" >&2
continue
fi
if test -z "${existing_owner}"; then
echo "ERROR: existing_owner is empty. line: '${line}'" >&2
continue
fi
if test -z "${existing_group}"; then
echo "ERROR: existing_group is empty. line: '${line}'" >&2
continue
fi
## -h file True if file is a symbolic Link.
## -u file True if file has its set-user-id bit set.
## -g file True if file has its set-group-id bit set.
if test -h "${file_name}"; then
## https://forums.whonix.org/t/disable-suid-binaries/7706/14
true "skip symlink: ${file_name}"
continue
fi
if test -d "${file_name}"; then
true "skip directory: ${file_name}"
continue
fi
local setuid setuid_output setsgid setsgid_output
setuid=""
setuid_output=""
if test -u "${file_name}"; then
setuid=true
setuid_output="set-user-id"
fi
setsgid=""
setsgid_output=""
if test -g "${file_name}"; then
setsgid=true
setsgid_output="set-group-id"
fi
local setuid_or_setsgid
setuid_or_setsgid=""
if test "${setuid}" = "true" || test "${setsgid}" = "true"; then
setuid_or_setsgid=true
fi
if test -z "${setuid_or_setsgid}"; then
continue
fi
## Remove suid / gid and execute permission for 'group' and 'others'.
## Similar to: chmod og-ugx /path/to/filename
## Removing execution permission is useful to make binaries such as 'su'
## fail closed rather than fail open if suid was removed from these.
## Do not remove read access since no security benefit and easier to
## manually undo for users.
## Are there suid or sgid binaries which are still useful if suid / sgid
## has been removed from these?
new_mode="744"
local is_exact_whitelisted
is_exact_whitelisted=""
for white_list_entry in ${exact_white_list}; do
if test "${file_name}" = "${white_list_entry}"; then
is_exact_whitelisted="true"
## Stop looping through the whitelist.
break
fi
done
local is_match_whitelisted
is_match_whitelisted=""
for matchwhite_list_entry in ${match_white_list}; do
if echo "${file_name}" | grep --quiet --fixed-strings "${matchwhite_list_entry}"; then
is_match_whitelisted="true"
## Stop looping through the match_white_list.
break
fi
done
local is_disable_whitelisted
is_disable_whitelisted=""
for disablematch_list_entry in ${disable_white_list:-}; do
if echo "${file_name}" | grep --quiet --fixed-strings "${disablematch_list_entry}"; then
is_disable_whitelisted="true"
## Stop looping through the disablewhitelist.
break
fi
done
if test "${whitelists_disable_all:-}" = "true"; then
true "INFO: whitelists_disable_all=true - ${setuid_output} ${setsgid_output} found - file_name: '${file_name}' | existing_mode: '${existing_mode}'"
elif test "${is_disable_whitelisted}" = "true"; then
true "INFO: white list disabled - ${setuid_output} ${setsgid_output} found - file_name: '${file_name}' | existing_mode: '${existing_mode}'"
else
if test "${is_exact_whitelisted}" = "true"; then
true "INFO: SKIP whitelisted - ${setuid_output} ${setsgid_output} found - file_name: '${file_name}' | existing_mode: '${existing_mode}'"
continue
fi
if test "${is_match_whitelisted}" = "true"; then
true "INFO: SKIP matchwhitelisted - ${setuid_output} ${setsgid_output} found - file_name: '${file_name}' | existing_mode: '${existing_mode}' | matchwhite_list_entry: '${matchwhite_list_entry}'"
continue
fi
fi
echo "INFO: ${setuid_output} ${setsgid_output} found - file_name: '${file_name}' | existing_mode: '${existing_mode}' | new_mode: '${new_mode}'"
# shellcheck disable=SC2086
if dpkg-statoverride ${dpkg_admindir_parameter_existing_mode} --list "${file_name}" >/dev/null; then
true "OK Existing mode already saved previously. Not saving again."
else
## Save existing_mode in separate database.
## Not using --update as not intending to enforce existing_mode.
# shellcheck disable=SC2086
echo_wrapper_silent_audit dpkg-statoverride ${dpkg_admindir_parameter_existing_mode} --add "${existing_owner}" "${existing_group}" "${existing_mode}" "${file_name}"
fi
## No need to check "dpkg-statoverride --list" for existing entries.
## If existing_mode was correct already, we would not have reached this
## point. Since existing_mode is incorrect, remove from dpkg-statoverride
## and re-add.
## Remove from real database.
echo_wrapper_silent_ignore dpkg-statoverride --remove "${file_name}"
## Remove from separate database.
# shellcheck disable=SC2086
echo_wrapper_silent_ignore dpkg-statoverride ${dpkg_admindir_parameter_new_mode} --remove "${file_name}"
## Add to real database and use --update to make changes on disk.
echo_wrapper_audit dpkg-statoverride --add --update "${existing_owner}" "${existing_group}" "${new_mode}" "${file_name}"
## Not using --update as this is only for recording.
# shellcheck disable=SC2086
echo_wrapper_silent_audit dpkg-statoverride ${dpkg_admindir_parameter_new_mode} --add "${existing_owner}" "${existing_group}" "${new_mode}" "${file_name}"
## /lib will hit ARG_MAX if using bash 'shopt -s globstar' and '/lib/**'.
## Using 'find' with '-perm /u=s,g=s' is faster and avoids ARG_MAX.
## https://forums.whonix.org/t/disable-suid-binaries/7706/17
done < <(find "${fso_to_process}" -perm /u=s,g=s -print0 | xargs -I{} -0 stat -c "%n %a %U %G" {})
## Sanity test.
if test ! "${should_be_counter}" = "${counter_actual}"; then
echo "INFO: fso_to_process: '${fso_to_process}' | counter_actual : '${counter_actual}'"
echo "INFO: fso_to_process: '${fso_to_process}' | should_be_counter: '${should_be_counter}'"
exit_code=202
echo "ERROR: counter does not check out." >&2
fi
}
set_file_perms() {
true "INFO: START parsing config_file: '${config_file}'"
local line
while read -r line || test -n "${line}"; do
if test -z "${line}"; then
continue
fi
if [[ "${line}" =~ ^# ]]; then
continue
fi
if [[ "${line}" =~ [0-9a-zA-Z/] ]]; then
true "OK line contains only white listed characters."
else
exit_code=200
echo "ERROR: cannot parse line with invalid character. line: '${line}'" >&2
## Safer to exit with error in this case.
## https://forums.whonix.org/t/disable-suid-binaries/7706/59
exit "${exit_code}"
fi
if test "${line}" = 'whitelists_disable_all=true'; then
whitelists_disable_all=true
echo "INFO: whitelists_disable_all=true - all whitelists disabled."
continue
fi
#global fso
local mode_from_config owner_from_config group_from_config capability_from_config
if ! read -r fso mode_from_config owner_from_config group_from_config capability_from_config <<<"${line}"; then
exit_code=201
echo "ERROR: cannot parse. line: '${line}'" >&2
## Debugging.
du -hs /tmp || true
echo "test -w /tmp: '$(test -w /tmp)'" >&2 || true
## Safer to exit with error in this case.
## https://forums.whonix.org/t/disable-suid-binaries/7706/59
exit "${exit_code}"
fi
## Debugging.
#echo "line: '${line}'"
#echo "fso: '${fso}'"
#echo "mode_from_config: '${mode_from_config}'"
#echo "owner_from_config: '${owner_from_config}'"
local fso_without_trailing_slash
fso_without_trailing_slash="${fso%/}"
if test "${mode_from_config}" = "disablewhitelist"; then
## TODO: test/add white spaces inside file name support
disable_white_list+="${fso} "
continue
fi
if test "${mode_from_config}" = "exactwhitelist"; then
## TODO: test/add white spaces inside file name support
exact_white_list+="${fso} "
continue
fi
if test "${mode_from_config}" = "matchwhitelist"; then
## TODO: test/add white spaces inside file name support
match_white_list+="${fso} "
continue
fi
if test ! -e "${fso}"; then
true "INFO: fso: '${fso}' - does not exist. This is likely normal."
continue
fi
## Use dpkg-statoverride so permissions are not reset during upgrades.
if test "${mode_from_config}" = "nosuid"; then
## If mode_from_config is "nosuid" the config does not set owner and
## group. Therefore do not enforce owner/group check.
add_nosuid_statoverride_entry
else
local string_length_of_mode_from_config
string_length_of_mode_from_config="${#mode_from_config}"
if test "${string_length_of_mode_from_config}" -gt "4"; then
echo "ERROR: Mode '${mode_from_config}' is invalid!" >&2
continue
fi
if test "${string_length_of_mode_from_config}" -lt "3"; then
echo "ERROR: Mode '${mode_from_config}' is invalid!" >&2
continue
fi
if ! grep --quiet --fixed-strings "${owner_from_config}:" "${store_dir}/private/passwd"; then
echo "ERROR: owner_from_config '${owner_from_config}' does not exist!" >&2
continue
fi
if ! grep --quiet --fixed-strings "${group_from_config}:" "${store_dir}/private/group"; then
echo "ERROR: group_from_config '${group_from_config}' does not exist!" >&2
continue
fi
local mode_for_grep
mode_for_grep="${mode_from_config}"
first_character_of_mode_from_config="${mode_from_config::1}"
if test "${first_character_of_mode_from_config}" = "0"; then
## Remove leading '0'.
mode_for_grep="${mode_from_config:1}"
fi
local stat_output
stat_output=""
if ! stat_output="$(stat -c "%n %a %U %G" "${fso_without_trailing_slash}")"; then
echo "ERROR: failed to run 'stat' for fso_without_trailing_slash: '${fso_without_trailing_slash}'!" >&2
continue
fi
local arr file_name existing_mode existing_owner existing_group
IFS=" " read -r -a arr <<< "${stat_output}"
file_name="${arr[0]}"
existing_mode="${arr[1]}"
existing_owner="${arr[2]}"
existing_group="${arr[3]}"
if test "${#arr[@]}" = 0; then
echo "ERROR: arr is empty. stat_output: '${stat_output}' | line: '${line}'" >&2
continue
fi
if test -z "${file_name}"; then
echo "ERROR: file_name is empty. stat_output: '${stat_output}' | line: '${line}'" >&2
continue
fi
if test -z "${existing_mode}"; then
echo "ERROR: existing_mode is empty. stat_output: '${stat_output}' | line: '${line}'" >&2
continue
fi
if test -z "${existing_owner}"; then
echo "ERROR: existing_owner is empty. stat_output: '${stat_output}' | line: '${line}'" >&2
continue
fi
if test -z "${existing_group}"; then
echo "ERROR: ${existing_group} is empty. stat_output: '${stat_output}' | line: '${line}'" >&2
continue
fi
## Check there is an entry for the fso.
##
## example: dpkg-statoverride --list | grep /home
## output:
## root root 755 /home
##
## dpkg-statoverride does not show leading '0'.
local dpkg_statoverride_list_output=""
local dpkg_statoverride_list_exit_code=0
dpkg_statoverride_list_output="$(dpkg-statoverride --list "${fso_without_trailing_slash}")" || {
dpkg_statoverride_list_exit_code=$?
true
}
if test "${dpkg_statoverride_list_exit_code}" = "0"; then
true "There is an fso entry. Check if owner/group/mode match."
local grep_line
grep_line="${owner_from_config} ${group_from_config} ${mode_for_grep} ${fso_without_trailing_slash}"
if echo "${dpkg_statoverride_list_output}" | grep --quiet --fixed-strings "${grep_line}"; then
true "OK The owner/group/mode matches. No further action required."
else
true "The owner/group/mode do not match, therefore remove and re-add the entry to update it."
## fso_without_trailing_slash instead of fso to prevent
## "dpkg-statoverride: warning: stripping trailing /"
# shellcheck disable=SC2086
if dpkg-statoverride ${dpkg_admindir_parameter_existing_mode} --list "${fso_without_trailing_slash}" >/dev/null; then
true "OK Existing mode already saved previously. No need to save again."
else
## Save existing_mode in separate database.
## Not using --update as not intending to enforce existing_mode.
# shellcheck disable=SC2086
echo_wrapper_silent_audit dpkg-statoverride ${dpkg_admindir_parameter_existing_mode} --add "${existing_owner}" "${existing_group}" "${existing_mode}" "${fso_without_trailing_slash}"
fi
# shellcheck disable=SC2086
echo_wrapper_silent_ignore dpkg-statoverride ${dpkg_admindir_parameter_new_mode} --remove "${fso_without_trailing_slash}"
## Remove from and add to real database.
echo_wrapper_silent_ignore dpkg-statoverride --remove "${fso_without_trailing_slash}"
echo_wrapper_audit dpkg-statoverride --add --update "${owner_from_config}" "${group_from_config}" "${mode_from_config}" "${fso_without_trailing_slash}"
## Save in separate database.
## Not using --update as this is only for saving.
# shellcheck disable=SC2086
echo_wrapper_silent_audit dpkg-statoverride ${dpkg_admindir_parameter_new_mode} --add "${owner_from_config}" "${group_from_config}" "${mode_from_config}" "${fso_without_trailing_slash}"
fi
else
true "There is no fso entry. Therefore add one."
# shellcheck disable=SC2086
if dpkg-statoverride ${dpkg_admindir_parameter_existing_mode} --list "${fso_without_trailing_slash}" >/dev/null; then
true "OK Existing mode already saved previously. No need to save again."
else
## Save existing_mode in separate database.
## Not using --update as not intending to enforce existing_mode.
# shellcheck disable=SC2086
echo_wrapper_silent_audit dpkg-statoverride ${dpkg_admindir_parameter_existing_mode} --add "${existing_owner}" "${existing_group}" "${existing_mode}" "${fso_without_trailing_slash}"
fi
## Add to real database.
echo_wrapper_audit dpkg-statoverride --add --update "${owner_from_config}" "${group_from_config}" "${mode_from_config}" "${fso_without_trailing_slash}"
## Save in separate database.
## Not using --update as this is only for saving.
# shellcheck disable=SC2086
echo_wrapper_silent_audit dpkg-statoverride ${dpkg_admindir_parameter_new_mode} --add "${owner_from_config}" "${group_from_config}" "${mode_from_config}" "${fso_without_trailing_slash}"
fi
fi
if test -z "${capability_from_config}"; then
continue
fi
if test "${capability_from_config}" = "none"; then
## https://forums.whonix.org/t/disable-suid-binaries/7706/45
## sudo setcap -r /bin/ping 2>/dev/null
## Failed to set capabilities on file '/bin/ping' (No data available)
## The value of the capability argument is not permitted for a file. Or
## the file is not a regular (non-symlink) file
## Therefore use echo_wrapper_ignore.
echo_wrapper_ignore setcap -r "${fso}"
getcap_output="$(getcap "${fso}")"
if test -n "${getcap_output}"; then
exit_code=205
echo "ERROR: removing capabilities for fso '${fso}' failed!" >&2
continue
fi
else
if ! capsh --print | grep --fixed-strings "Bounding set" | grep --quiet "${capability_from_config}"; then
echo "ERROR: capability_from_config '${capability_from_config}' does not exist!" >&2
continue
fi
## feature request: dpkg-statoverride: support for capabilities
## https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=502580
echo_wrapper_audit setcap "${capability_from_config}+ep" "${fso}"
fi
done <"${config_file}"
true "INFO: END parsing config_file: '${config_file}'"
}
parse_config_folder() {
touch "${store_dir}/private/passwd"
chmod og-rwx "${store_dir}/private/passwd"
touch "${store_dir}/private/group"
chmod og-rwx "${store_dir}/private/group"
local passwd_file_contents_temp
## Query contents of password and group databases only once and buffer them
##
## If we don't buffer we sometimes get incorrect results when checking for
## entries using 'if getent passwd | grep --quiet '^root:'; ...' since
## 'grep' exits after the first match in this case causing 'getent' to
## receive SIGPIPE, which then fails the pipeline since 'set -o pipefail' is
## set for this script.
passwd_file_contents_temp=$(getent passwd)
echo "${passwd_file_contents_temp}" | tee "${store_dir}/private/passwd" >/dev/null
group_file_contents_temp=$(getent group)
echo "${group_file_contents_temp}" | tee "${store_dir}/private/group" >/dev/null
#passwd_file_contents="$(cat "${store_dir}/private/passwd")"
#group_file_contents="$(cat "${store_dir}/private/group")"
shopt -s nullglob
for config_file in \
/etc/permission-hardener.d/*.conf \
/usr/local/etc/permission-hardener.d/*.conf \
/etc/permission-hardening.d/*.conf \
/usr/local/etc/permission-hardening.d/*.conf
do
set_file_perms
done
}
apply() {
check_root
make_store_dir
sanity_tests
parse_config_folder
echo "\
INFO: To compare the current and previous permission modes:
Install 'meld' (or preferred diff tool) for comparison of file mode changes:
sudo apt install --no-install-recommends meld
Use 'meld' or another diff tool to view the differences:
meld ${store_dir}/existing_mode/statoverride ${store_dir}/new_mode/statoverride"
}
spare() {
check_root
make_store_dir
remove_file="${1}"
exit_code=0
dpkg_admindir_parameter_existing_mode="--admindir ${store_dir}/existing_mode"
dpkg_admindir_parameter_new_mode="--admindir ${store_dir}/new_mode"
if test ! -f "${store_dir}/existing_mode/statoverride"; then
return 0
fi
local line
while read -r line; do
## example line:
## root root 4755 /usr/lib/eject/dmcrypt-get-device
local owner group mode file_name
if ! read -r owner group mode file_name <<< "${line}"; then
exit_code=201
echo "ERROR: cannot parse line: ${line}" >&2
continue
fi
true "owner: '${owner}' group: '${group}' mode: '${mode}' file_name: '${file_name}'"
if test "${remove_file}" = "all"; then
verbose=""
remove_one=false
else
if test "${remove_file}" = "${file_name}"; then
verbose="--verbose"
remove_one=true
echo "${remove_one}" | tee "${store_dir}/remove_one" >/dev/null
else
echo "false" | tee "${store_dir}/remove_one" >/dev/null
continue
fi
fi
if test "${remove_one}" = "true"; then
set -o xtrace
fi
if test -e "${file_name}"; then
# shellcheck disable=SC2086
chown ${verbose} "${owner}:${group}" "${file_name}" || exit_code=202
## chmod need to be run after chown since chown removes suid.
## https://unix.stackexchange.com/questions/53665/chown-removes-setuid-bit-bug-or-feature
# shellcheck disable=SC2086
chmod ${verbose} "${mode}" "${file_name}" || exit_code=203
else
echo "INFO: file_name: '${file_name}' - does not exist. This is likely normal."
fi
dpkg-statoverride --remove "${file_name}" &>/dev/null || true
# shellcheck disable=SC2086
dpkg-statoverride ${dpkg_admindir_parameter_existing_mode} --remove "${file_name}" &>/dev/null || true
# shellcheck disable=SC2086
dpkg-statoverride ${dpkg_admindir_parameter_new_mode} --remove "${file_name}" &>/dev/null || true
if test "${remove_one}" = "true"; then
set +o xtrace
break
fi
done < "${store_dir}/existing_mode/statoverride"
if test ! "${remove_file}" = "all"; then
if test "$(cat "${store_dir}/remove_one")" = "false"; then
echo "INFO: no file was removed.
File '${remove_file}' has not been removed from SUID Disabler and Permission Hardener during this invocation of this program.
Note: This is expected if already done earlier.
Note: This program expects the full path to the file. Example:
$0 disable /usr/bin/newgrp
The following syntax will not work:
$0 disable program-name
The following example will not work:
$0 disable newgrp
To remove all:
$0 disable all
This change might not be permanent (because of the permission-hardener.service systemd unit). For full instructions, see:
https://www.kicksecure.com/wiki/SUID_Disabler_and_Permission_Hardener
To view list of changed by SUID Disabler and Permission Hardener:
https://www.kicksecure.com/wiki/SUID_Disabler_and_Permission_Hardener#View_List_of_Permissions_Changed_by_SUID_Disabler_and_Permission_Hardener
For re-enabling any specific SUID binary:
https://www.kicksecure.com/wiki/SUID_Disabler_and_Permission_Hardener#Re-Enable_Specific_SUID_Binaries
For completely disabling SUID Disabler and Permission Hardener:
https://www.kicksecure.com/wiki/SUID_Disabler_and_Permission_Hardener#Disable_SUID_Disabler_and_Permission_Hardener"
fi
fi
}
check_root(){
if test "$(id -u)" != "0"; then
echo "ERROR: Not running as root, aborting."
exit 1
fi
}
usage(){
echo "Usage: ${0##*/} enable
${0##*/} disable [FILE|all]
Examples:
${0##*/} enable
${0##*/} disable all
${0##*/} disable /usr/bin/newgrp" >&2
exit "${1}"
}
case "${1:-}" in
enable) shift; apply "$@";;
disable)
shift
case "${1:-}" in
"") usage 1;;
*) spare "${1}";;
esac
;;
-h|--help) usage 0;;
*) usage 1;;
esac
if test "${exit_code}" != "0"; then
echo "ERROR: Exiting with non-zero exit code: '${exit_code}'" >&2
fi
exit "${exit_code}"

View File

@ -1,510 +0,0 @@
#!/bin/bash
## Copyright (C) 2012 - 2023 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
## https://forums.whonix.org/t/disable-suid-binaries/7706
## https://forums.whonix.org/t/re-mount-home-and-other-with-noexec-and-nosuid-among-other-useful-mount-options-for-better-security/7707
## To undo:
## sudo /usr/libexec/security-misc/permission-hardening-undo
#set -x
set -e
set -o pipefail
exit_code=0
mkdir --parents /var/lib/permission-hardening/private
mkdir --parents /var/lib/permission-hardening/existing_mode
mkdir --parents /var/lib/permission-hardening/new_mode
dpkg_admindir_parameter_existing_mode="--admindir /var/lib/permission-hardening/existing_mode"
dpkg_admindir_parameter_new_mode="--admindir /var/lib/permission-hardening/new_mode"
echo_wrapper_ignore() {
echo "run: $@"
"$@" 2>/dev/null || true
}
echo_wrapper_silent_ignore() {
#echo "run: $@"
"$@" 2>/dev/null || true
}
echo_wrapper_audit() {
echo "run: $@"
return_code=0
"$@" || \
{ \
return_code="$?" ; \
exit_code=203 ; \
echo "ERROR: above command failed with exit code '$return_code'! calling function name: '${FUNCNAME[1]}'" >&2 ; \
};
}
echo_wrapper_silent_audit() {
#echo "run (debugging): $@"
return_code=0
"$@" || \
{ \
return_code="$?" ; \
exit_code=204 ; \
echo "ERROR: above command '$@' failed with exit code '$return_code'! calling function name: '${FUNCNAME[1]}'" >&2 ; \
};
}
sanity_tests() {
echo_wrapper_silent_audit which \
capsh getcap setcap stat find dpkg-statoverride getent xargs grep 1>/dev/null
}
add_nosuid_statoverride_entry() {
local fso_to_process
fso_to_process="$fso"
local should_be_counter
should_be_counter="$(find "$fso_to_process" -perm /u=s,g=s | wc -l)" || true
local counter_actual
counter_actual=0
local line
while read -r line; do
true "line: $line"
counter_actual="$(( counter_actual + 1 ))"
local arr file_name existing_mode existing_owner existing_group
arr=($line)
file_name="${arr[0]}"
existing_mode="${arr[1]}"
existing_owner="${arr[2]}"
existing_group="${arr[3]}"
if [ "$arr" = "" ]; then
echo "ERROR: arr is empty. line: '$line'" >&2
continue
fi
if [ "$file_name" = "" ]; then
echo "ERROR: file_name is empty. line: '$line'" >&2
continue
fi
if [ "$existing_mode" = "" ]; then
echo "ERROR: existing_mode is empty. line: '$line'" >&2
continue
fi
if [ "$existing_owner" = "" ]; then
echo "ERROR: existing_owner is empty. line: '$line'" >&2
continue
fi
if [ "$existing_group" = "" ]; then
echo "ERROR: existing_group is empty. line: '$line'" >&2
continue
fi
## -h file True if file is a symbolic Link.
## -u file True if file has its set-user-id bit set.
## -g file True if file has its set-group-id bit set.
if test -h "$file_name" ; then
## https://forums.whonix.org/t/disable-suid-binaries/7706/14
true "skip symlink: $file_name"
continue
fi
if test -d "$file_name" ; then
true "skip directory: $file_name"
continue
fi
local setuid setuid_output setsgid setsgid_output
setuid=""
setuid_output=""
if test -u "$file_name" ; then
setuid=true
setuid_output="set-user-id"
fi
setsgid=""
setsgid_output=""
if test -g "$file_name" ; then
setsgid=true
setsgid_output="set-group-id"
fi
local setuid_or_setsgid
setuid_or_setsgid=""
if [ "$setuid" = "true" ] || [ "$setsgid" = "true" ]; then
setuid_or_setsgid=true
fi
if [ "$setuid_or_setsgid" = "" ]; then
continue
fi
## Remove suid / gid and execute permission for 'group' and 'others'.
## Similar to: chmod og-ugx /path/to/filename
## Removing execution permission is useful to make binaries such as 'su' fail closed rather
## than fail open if suid was removed from these.
## Do not remove read access since no security benefit and easier to manually undo for users.
## Are there suid or sgid binaries which are still useful if suid / sgid has been removed from these?
new_mode="744"
local is_exact_whitelisted
is_exact_whitelisted=""
for white_list_entry in $exact_white_list ; do
if [ "$file_name" = "$white_list_entry" ]; then
is_exact_whitelisted="true"
## Stop looping through the whitelist.
break
fi
done
local is_match_whitelisted
is_match_whitelisted=""
for matchwhite_list_entry in $match_white_list ; do
if echo "$file_name" | grep --quiet --fixed-strings "$matchwhite_list_entry" ; then
is_match_whitelisted="true"
## Stop looping through the match_white_list.
break
fi
done
local is_disable_whitelisted
is_disable_whitelisted=""
for disablematch_list_entry in $disable_white_list ; do
if echo "$file_name" | grep --quiet --fixed-strings "$disablematch_list_entry" ; then
is_disable_whitelisted="true"
## Stop looping through the disablewhitelist.
break
fi
done
if [ "$whitelists_disable_all" = "true" ]; then
true "INFO: whitelists_disable_all=true - $setuid_output $setsgid_output found - file_name: '$file_name' | existing_mode: '$existing_mode'"
elif [ "$is_disable_whitelisted" = "true" ]; then
true "INFO: white list disabled - $setuid_output $setsgid_output found - file_name: '$file_name' | existing_mode: '$existing_mode'"
else
if [ "$is_exact_whitelisted" = "true" ]; then
true "INFO: SKIP whitelisted - $setuid_output $setsgid_output found - file_name: '$file_name' | existing_mode: '$existing_mode'"
continue
fi
if [ "$is_match_whitelisted" = "true" ]; then
true "INFO: SKIP matchwhitelisted - $setuid_output $setsgid_output found - file_name: '$file_name' | existing_mode: '$existing_mode' | matchwhite_list_entry: '$matchwhite_list_entry'"
continue
fi
fi
echo "INFO: $setuid_output $setsgid_output found - file_name: '$file_name' | existing_mode: '$existing_mode' | new_mode: '$new_mode'"
if dpkg-statoverride $dpkg_admindir_parameter_existing_mode --list "$file_name" >/dev/null ; then
true "OK Existing mode already saved previously. No need to save again."
else
## Save existing_mode in separate database.
## Not using --update as not intending to enforce existing_mode.
echo_wrapper_silent_audit dpkg-statoverride $dpkg_admindir_parameter_existing_mode --add "$existing_owner" "$existing_group" "$existing_mode" "$file_name"
fi
## No need to check "dpkg-statoverride --list" for existing entries.
## If existing_mode was correct already, we would not have reached this point.
## Since existing_mode is incorrect, remove from dpkg-statoverride and re-add.
## Remove from real database.
echo_wrapper_silent_ignore dpkg-statoverride --remove "$file_name"
## Remove from separate database.
echo_wrapper_silent_ignore dpkg-statoverride $dpkg_admindir_parameter_new_mode --remove "$file_name"
## Add to real database and use --update to make changes on disk.
echo_wrapper_audit dpkg-statoverride --add --update "$existing_owner" "$existing_group" "$new_mode" "$file_name"
## Not using --update as this is only for recording.
echo_wrapper_silent_audit dpkg-statoverride $dpkg_admindir_parameter_new_mode --add "$existing_owner" "$existing_group" "$new_mode" "$file_name"
## /lib will hit ARG_MAX if using bash 'shopt -s globstar' and '/lib/**'.
## Using 'find' with '-perm /u=s,g=s' is faster and avoids ARG_MAX.
## https://forums.whonix.org/t/disable-suid-binaries/7706/17
done < <( find "$fso_to_process" -perm /u=s,g=s -print0 | xargs -I{} -0 stat -c "%n %a %U %G" {} )
## Sanity test.
if [ ! "$should_be_counter" = "$counter_actual" ]; then
echo "INFO: fso_to_process: '$fso_to_process' | counter_actual : '$counter_actual'"
echo "INFO: fso_to_process: '$fso_to_process' | should_be_counter: '$should_be_counter'"
exit_code=202
echo "ERROR: counter does not check out." >&2
fi
}
set_file_perms() {
true "INFO: START parsing config_file: '$config_file'"
local line
while read -r line || [[ -n "${line}" ]]; do
if [ "$line" = "" ]; then
continue
fi
if [[ "$line" =~ ^# ]]; then
continue
fi
if [[ "$line" =~ [0-9a-zA-Z/] ]]; then
true "OK line contains only white listed characters."
else
exit_code=200
echo "ERROR: cannot parse line with invalid character. line: '$line'" >&2
## Safer to exit with error in this case.
## https://forums.whonix.org/t/disable-suid-binaries/7706/59
exit "$exit_code"
fi
if [ "$line" = 'whitelists_disable_all=true' ]; then
whitelists_disable_all=true
echo "INFO: whitelists_disable_all=true - all whitelists disabled."
continue
fi
#global fso
local mode_from_config owner_from_config group_from_config capability_from_config
if ! read -r fso mode_from_config owner_from_config group_from_config capability_from_config <<< "$line" ; then
exit_code=201
echo "ERROR: cannot parse. line: '$line'" >&2
## Debugging.
du -hs /tmp || true
echo "test -w /tmp: '$(test -w /tmp)'" >&2 || true
## Safer to exit with error in this case.
## https://forums.whonix.org/t/disable-suid-binaries/7706/59
exit "$exit_code"
fi
## Debugging.
#echo "line: '$line'"
#echo "fso: '$fso'"
#echo "mode_from_config: '$mode_from_config'"
#echo "owner_from_config: '$owner_from_config'"
local fso_without_trailing_slash
fso_without_trailing_slash="${fso%/}"
if [ "$mode_from_config" = "disablewhitelist" ]; then
## TODO: test/add white spaces inside file name support
disable_white_list+="$fso "
continue
fi
if [ "$mode_from_config" = "exactwhitelist" ]; then
## TODO: test/add white spaces inside file name support
exact_white_list+="$fso "
continue
fi
if [ "$mode_from_config" = "matchwhitelist" ]; then
## TODO: test/add white spaces inside file name support
match_white_list+="$fso "
continue
fi
if [ ! -e "$fso" ]; then
true "INFO: fso: '$fso' - does not exist. This is likely normal."
continue
fi
## Use dpkg-statoverride so permissions are not reset during upgrades.
if [ "$mode_from_config" = "nosuid" ]; then
## If mode_from_config is "nosuid" the config does not set owner and
## group. Therefore do not enforce owner/group check.
add_nosuid_statoverride_entry
else
local string_length_of_mode_from_config
string_length_of_mode_from_config="${#mode_from_config}"
if [ "$string_length_of_mode_from_config" -gt "4" ]; then
echo "ERROR: Mode '$mode_from_config' is invalid!" >&2
continue
fi
if [ "$string_length_of_mode_from_config" -lt "3" ]; then
echo "ERROR: Mode '$mode_from_config' is invalid!" >&2
continue
fi
if ! grep --quiet --fixed-strings "${owner_from_config}:" /var/lib/permission-hardening/private/passwd ; then
echo "ERROR: owner_from_config '$owner_from_config' does not exist!" >&2
continue
fi
if ! grep --quiet --fixed-strings "${group_from_config}:" /var/lib/permission-hardening/private/group ; then
echo "ERROR: group_from_config '$group_from_config' does not exist!" >&2
continue
fi
local mode_for_grep
mode_for_grep="$mode_from_config"
first_character_of_mode_from_config="${mode_from_config::1}"
if [ "$first_character_of_mode_from_config" = "0" ]; then
## Remove leading '0'.
mode_for_grep="${mode_from_config:1}"
fi
local stat_output
stat_output=""
if ! stat_output="$(stat -c "%n %a %U %G" "$fso_without_trailing_slash")" ; then
echo "ERROR: failed to run 'stat' for fso_without_trailing_slash: '$fso_without_trailing_slash'!" >&2
continue
fi
local arr file_name existing_mode existing_owner existing_group
arr=($stat_output)
file_name="${arr[0]}"
existing_mode="${arr[1]}"
existing_owner="${arr[2]}"
existing_group="${arr[3]}"
if [ "$arr" = "" ]; then
echo "ERROR: arr is empty. stat_output: '$stat_output' | line: '$line'" >&2
continue
fi
if [ "$file_name" = "" ]; then
echo "ERROR: file_name is empty. stat_output: '$stat_output' | line: '$line'" >&2
continue
fi
if [ "$existing_mode" = "" ]; then
echo "ERROR: existing_mode is empty. stat_output: '$stat_output' | line: '$line'" >&2
continue
fi
if [ "$existing_owner" = "" ]; then
echo "ERROR: existing_owner is empty. stat_output: '$stat_output' | line: '$line'" >&2
continue
fi
if [ "$existing_group" = "" ]; then
echo "ERROR: $existing_group is empty. stat_output: '$stat_output' | line: '$line'" >&2
continue
fi
## Check there is an entry for the fso.
##
## example: dpkg-statoverride --list | grep /home
## output:
## root root 755 /home
##
## dpkg-statoverride does not show leading '0'.
local dpkg_statoverride_list_output=""
local dpkg_statoverride_list_exit_code=0
dpkg_statoverride_list_output="$(dpkg-statoverride --list "$fso_without_trailing_slash")" || { dpkg_statoverride_list_exit_code=$? ; true; };
if [ "$dpkg_statoverride_list_exit_code" = "0" ]; then
true "There is an fso entry. Check if owner/group/mode match."
local grep_line
grep_line="$owner_from_config $group_from_config $mode_for_grep $fso_without_trailing_slash"
if echo "$dpkg_statoverride_list_output" | grep --quiet --fixed-strings "$grep_line" ; then
true "OK The owner/group/mode matches. No further action required."
else
true "The owner/group/mode do not match, therefore remove and re-add the entry to update it."
## fso_without_trailing_slash instead of fso to prevent
## "dpkg-statoverride: warning: stripping trailing /"
if dpkg-statoverride $dpkg_admindir_parameter_existing_mode --list "$fso_without_trailing_slash" >/dev/null ; then
true "OK Existing mode already saved previously. No need to save again."
else
## Save existing_mode in separate database.
## Not using --update as not intending to enforce existing_mode.
echo_wrapper_silent_audit dpkg-statoverride $dpkg_admindir_parameter_existing_mode --add "$existing_owner" "$existing_group" "$existing_mode" "$fso_without_trailing_slash"
fi
echo_wrapper_silent_ignore dpkg-statoverride $dpkg_admindir_parameter_new_mode --remove "$fso_without_trailing_slash"
## Remove from and add to real database.
echo_wrapper_silent_ignore dpkg-statoverride --remove "$fso_without_trailing_slash"
echo_wrapper_audit dpkg-statoverride --add --update "$owner_from_config" "$group_from_config" "$mode_from_config" "$fso_without_trailing_slash"
## Save in separate database.
## Not using --update as this is only for saving.
echo_wrapper_silent_audit dpkg-statoverride $dpkg_admindir_parameter_new_mode --add "$owner_from_config" "$group_from_config" "$mode_from_config" "$fso_without_trailing_slash"
fi
else
true "There is no fso entry. Therefore add one."
if dpkg-statoverride $dpkg_admindir_parameter_existing_mode --list "$fso_without_trailing_slash" >/dev/null ; then
true "OK Existing mode already saved previously. No need to save again."
else
## Save existing_mode in separate database.
## Not using --update as not intending to enforce existing_mode.
echo_wrapper_silent_audit dpkg-statoverride $dpkg_admindir_parameter_existing_mode --add "$existing_owner" "$existing_group" "$existing_mode" "$fso_without_trailing_slash"
fi
## Add to real database.
echo_wrapper_audit dpkg-statoverride --add --update "$owner_from_config" "$group_from_config" "$mode_from_config" "$fso_without_trailing_slash"
## Save in separate database.
## Not using --update as this is only for saving.
echo_wrapper_silent_audit dpkg-statoverride $dpkg_admindir_parameter_new_mode --add "$owner_from_config" "$group_from_config" "$mode_from_config" "$fso_without_trailing_slash"
fi
fi
if [ "$capability_from_config" = "" ]; then
continue
fi
if [ "$capability_from_config" = "none" ]; then
## https://forums.whonix.org/t/disable-suid-binaries/7706/45
# sudo setcap -r /bin/ping 2>/dev/null
# Failed to set capabilities on file '/bin/ping' (No data available)
# The value of the capability argument is not permitted for a file. Or the file is not a regular (non-symlink) file
## Therefore use echo_wrapper_ignore.
echo_wrapper_ignore setcap -r "$fso"
getcap_output="$(getcap "$fso")"
if [ ! "$getcap_output" = "" ]; then
exit_code=205
echo "ERROR: removing capabilities for fso '$fso' failed!" >&2
continue
fi
else
if ! capsh --print | grep --fixed-strings "Bounding set" | grep --quiet "$capability_from_config" ; then
echo "ERROR: capability_from_config '$capability_from_config' does not exist!" >&2
continue
fi
## feature request: dpkg-statoverride: support for capabilities
## https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=502580
echo_wrapper_audit setcap "${capability_from_config}+ep" "$fso"
fi
done < "$config_file"
true "INFO: END parsing config_file: '$config_file'"
}
parse_config_folder() {
touch /var/lib/permission-hardening/private/passwd
chmod og-rwx /var/lib/permission-hardening/private/passwd
touch /var/lib/permission-hardening/private/group
chmod og-rwx /var/lib/permission-hardening/private/group
local passwd_file_contents_temp
# Query contents of password and group databases only once and buffer them
#
# If we don't buffer we sometimes get incorrect results when checking for entries using
# 'if getent passwd | grep --quiet '^root:'; ...' since 'grep' exits after the first match in
# this case causing 'getent' to receive SIGPIPE, which then fails the pipeline since
# 'set -o pipefail' is set for this script.
passwd_file_contents_temp=$(getent passwd)
echo "$passwd_file_contents_temp" | tee /var/lib/permission-hardening/private/passwd >/dev/null
group_file_contents_temp=$(getent group)
echo "$group_file_contents_temp" | tee /var/lib/permission-hardening/private/group >/dev/null
passwd_file_contents=$(cat /var/lib/permission-hardening/private/passwd)
group_file_contents=$(cat /var/lib/permission-hardening/private/group)
shopt -s nullglob
for config_file in /etc/permission-hardening.d/*.conf /usr/local/etc/permission-hardening.d/*.conf; do
set_file_perms
done
}
sanity_tests
parse_config_folder
echo "\
INFO: To compare the current and previous permission modes:
1. Install 'meld' (or similar) for an easier comparison of file changes:
sudo apt install --no-install-recommends meld
2. Use 'meld' to view the differences:
meld /var/lib/permission-hardening/existing_mode/statoverride /var/lib/permission-hardening/new_mode/statoverride"
if [ ! "$exit_code" = "0" ]; then
echo "ERROR: Will exit with non-zero exit code: '$exit_code'" >&2
fi
exit "$exit_code"

View File

@ -1,136 +0,0 @@
#!/bin/bash
## Copyright (C) 2012 - 2023 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
## See the file COPYING for copying conditions.
#set -x
set -e
set -o pipefail
if [ "$1" = "all" ]; then
remove_file="all"
elif [ ! "$1" = "" ]; then
remove_file="$1"
else
echo "ERROR: need to give parameter 'all' or a filename.
examples:
$0 all
$0 /usr/bin/newgrp
" >&2
fi
exit_code=0
dpkg_admindir_parameter_existing_mode="--admindir /var/lib/permission-hardening/existing_mode"
dpkg_admindir_parameter_new_mode="--admindir /var/lib/permission-hardening/new_mode"
undo_permission_hardening() {
if [ ! -f /var/lib/permission-hardening/existing_mode/statoverride ]; then
return 0
fi
local line
while read -r line; do
## example line:
## root root 4755 /usr/lib/eject/dmcrypt-get-device
local owner group mode file_name
if ! read -r owner group mode file_name <<< "$line" ; then
exit_code=201
echo "ERROR: cannot parse line: $line" >&2
continue
fi
true "owner: '$owner' group: '$group' mode: '$mode' file_name: '$file_name'"
if [ "$remove_file" = "all" ]; then
do_proceed=true
verbose_maybe=""
else
if [ "$remove_file" = "$file_name" ]; then
do_proceed=true
verbose_maybe="--verbose"
remove_one=true
else
do_proceed=false
verbose_maybe=""
fi
fi
if [ "$do_proceed" = "false" ]; then
continue
fi
if [ "$remove_one" = "true" ]; then
set -x
fi
if test -e "$file_name" ; then
chown $verbose_maybe "${owner}:${group}" "$file_name" || exit_code=202
## chmod need to be run after chown since chown removes suid.
## https://unix.stackexchange.com/questions/53665/chown-removes-setuid-bit-bug-or-feature
chmod $verbose_maybe "$mode" "$file_name" || exit_code=203
else
echo "INFO: file_name: '$file_name' - does not exist. This is likely normal."
fi
dpkg-statoverride --remove "$file_name" &>/dev/null || true
dpkg-statoverride $dpkg_admindir_parameter_existing_mode --remove "$file_name" &>/dev/null || true
dpkg-statoverride $dpkg_admindir_parameter_new_mode --remove "$file_name" &>/dev/null || true
if [ "$remove_one" = "true" ]; then
set +x
break
fi
done < "/var/lib/permission-hardening/existing_mode/statoverride"
}
undo_permission_hardening
if [ ! "$remove_file" = "all" ]; then
if [ ! "$remove_one" = "true" ]; then
echo "INFO: none removed.
File '$remove_file' has not removed from SUID Disabler and Permission Hardener during this invocation of this program.
Note: This is expected if already done earlier.
Note: This program expects the full path to the file. Example:
$0 /usr/bin/newgrp
The following syntax will not work:
$0 program-name
The following example will not work:
$0 newgrp
To remove all:
$0 all
This change might not be permanent (because of the permission-hardening.service systemd unit). For full instructions, see:
https://www.kicksecure.com/wiki/SUID_Disabler_and_Permission_Hardener
To view list of changed by SUID Disabler and Permission Hardener:
https://www.kicksecure.com/wiki/SUID_Disabler_and_Permission_Hardener#View_List_of_Permissions_Changed_by_SUID_Disabler_and_Permission_Hardener
For re-enabling any specific SUID binary:
https://www.kicksecure.com/wiki/SUID_Disabler_and_Permission_Hardener#Re-Enable_Specific_SUID_Binaries
For completely disabling SUID Disabler and Permission Hardener:
https://www.kicksecure.com/wiki/SUID_Disabler_and_Permission_Hardener#Disable_SUID_Disabler_and_Permission_Hardener"
fi
fi
if [ ! "$exit_code" = "0" ]; then
echo "ERROR: Will exit with non-zero exit code: '$exit_code'" >&2
fi
exit "$exit_code"