mirror of
https://github.com/Kicksecure/security-misc.git
synced 2025-02-13 04:31:21 -05:00
Refactor permission-hardener to be more idempotent
This commit is contained in:
Aaron Rainbolt
parent
2f3a2bce77
commit
83d3867959
3
debian/security-misc.maintscript
vendored
3
debian/security-misc.maintscript
vendored
@ -106,3 +106,6 @@ rm_conffile /etc/default/grub.d/41_quiet.cfg
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## moved to usability-misc
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rm_conffile /etc/dkms/framework.conf.d/30_security-misc.conf
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## renamed to reflect the fact that this uses a whitelist
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rm_conffile /usr/lib/permission-hardener.d/25_default_passwd.conf
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File diff suppressed because it is too large
Load Diff
748
usr/bin/permission-hardener-old
Executable file
748
usr/bin/permission-hardener-old
Executable file
@ -0,0 +1,748 @@
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#!/bin/bash
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## Copyright (C) 2012 - 2024 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
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## See the file COPYING for copying conditions.
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## https://forums.whonix.org/t/disable-suid-binaries/7706
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## https://forums.whonix.org/t/re-mount-home-and-other-with-noexec-and-nosuid-among-other-useful-mount-options-for-better-security/7707
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## dpkg-statoverride does not support end-of-options ("--").
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set -o errexit -o nounset -o pipefail
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exit_code=0
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store_dir="/var/lib/permission-hardener"
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dpkg_admindir_parameter_existing_mode="--admindir ${store_dir}/existing_mode"
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dpkg_admindir_parameter_new_mode="--admindir ${store_dir}/new_mode"
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delimiter="#permission-hardener-delimiter#"
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# shellcheck disable=SC1091
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source /usr/libexec/helper-scripts/safe_echo.sh
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# shellcheck disable=SC2034
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log_level=notice
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# shellcheck disable=SC1091
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source /usr/libexec/helper-scripts/log_run_die.sh
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echo_wrapper_ignore() {
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if test "${1}" = "verbose"; then
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shift
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log notice "Executing: $*"
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else
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shift
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fi
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"$@" 2>/dev/null || true
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}
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echo_wrapper_audit() {
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if test "${1}" = "verbose"; then
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shift
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log notice "Executing: $*"
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else
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shift
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fi
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return_code=0
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"$@" ||
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{
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return_code="$?"
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exit_code=203
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log error "Command '$*' failed with exit code '${return_code}'! calling function name: '${FUNCNAME[1]}'" >&2
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}
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}
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make_store_dir(){
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mkdir --parents "${store_dir}/private"
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mkdir --parents "${store_dir}/existing_mode"
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mkdir --parents "${store_dir}/new_mode"
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}
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## Some tools may fail on newlines and even variable assignment to array may
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## fail if a variable that will be assigned to an array element contains
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## characters that are used as delimiters.
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block_newlines(){
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local newline_variable newline_value
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newline_variable="${1}"
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newline_value="${2}"
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## dpkg-statoverride: error: path may not contain newlines
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#if [[ "${newline_value}" == *$'\n'* ]]; then
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if [[ "${newline_value}" != "${newline_value//$'\n'/NEWLINE}" ]]; then
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log warn "Skipping ${newline_variable} that contains newlines: '${newline_value}'" >&2
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return 1
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fi
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}
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output_stat(){
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local file_name
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file_name="${1}"
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if test -z "${file_name}"; then
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log error "File name is empty. file_name: '${file_name}'" >&2
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return 1
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fi
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block_newlines file "${file_name}"
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## dpkg-statoverride can actually handle '--file-name'.
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# if [[ $file_name == --* ]]; then
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# log warn "File name starts with '--'. This would be interpreted by dpkg-statoverride as an option. Skipping. file_name: '${file_name}'" >&2
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# return 1
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# fi
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declare -a arr
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local file_name_from_stat stat_output stat_output_newlined
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if ! stat_output="$(stat --format="%a${delimiter}%U${delimiter}%G${delimiter}%n${delimiter}" -- "${file_name}")"; then
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log error "Failed to run 'stat' on file: '${file_name}'!" >&2
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return 1
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fi
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if [ "$stat_output" = "" ]; then
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log error "stat_output is empty.
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File name: '${file_name}'
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Stat output: '${stat_output}'
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stat_output_newlined: '${stat_output_newlined}'
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line: '${line}'
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" >&2
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return 1
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fi
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stat_output_newlined="$(printf '%s\n' "${stat_output//${delimiter}/$'\n'}")"
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if test "${stat_output_newlined}" = ""; then
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log error "stat_output_newlined is empty.
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File name: '${file_name}'
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Stat output: '${stat_output}'
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stat_output_newlined: '${stat_output_newlined}'
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line: '${line}'
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" >&2
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return 1
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fi
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readarray -t arr <<< "${stat_output_newlined}"
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if test "${#arr[@]}" = 0; then
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log error "Array length is 0.
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File name: '${file_name}'
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Stat output: '${stat_output}'
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stat_output_newlined: '${stat_output_newlined}'
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line: '${line}'
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" >&2
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return 1
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fi
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existing_mode="${arr[0]}"
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existing_owner="${arr[1]}"
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existing_group="${arr[2]}"
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file_name_from_stat="${arr[3]}"
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if [ ! "$file_name" = "$file_name_from_stat" ]; then
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log error "\
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File name is different from file name received from stat:
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File name: '${file_name}'
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File name from stat: '${file_name_from_stat}'
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line: '${line}'
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" >&2
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return 1
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fi
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if test -z "${existing_mode}"; then
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log error "Existing mode is empty. Stat output: '${stat_output}', line: '${line}'" >&2
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return 1
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fi
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if test -z "${existing_owner}"; then
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log error "Existing owner is empty. Stat output: '${stat_output}', line: '${line}'" >&2
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return 1
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fi
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if test -z "${existing_group}"; then
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log error "Existing group is empty. Stat output: '${stat_output}', line: '${line}'" >&2
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return 1
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fi
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}
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sanity_tests() {
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echo_wrapper_audit silent \
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which \
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capsh getcap setcap stat find dpkg-statoverride getent grep 1>/dev/null
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}
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add_nosuid_statoverride_entry() {
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local fso_to_process
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fso_to_process="${fso}"
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local should_be_counter
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should_be_counter=0
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local counter_actual
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counter_actual=0
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local dummy_line
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while IFS="" read -r -d "" dummy_line; do
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log info "Test would parse line: '${dummy_line}'"
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should_be_counter=$((should_be_counter + 1))
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done < <(safe_echo_nonewline "${fso_to_process}" | find -files0-from - -perm /u=s,g=s -print0)
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## False positive on SC2185 (find without path argument) #1748
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## https://github.com/koalaman/shellcheck/issues/1748
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##
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## /usr/lib will hit ARG_MAX if using bash 'shopt -s globstar' and '/usr/lib/**'.
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## Using 'find' with '-perm /u=s,g=s' is faster and avoids ARG_MAX.
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## https://forums.whonix.org/t/disable-suid-binaries/7706/17
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local line
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while IFS="" read -r -d "" file_name; do
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counter_actual=$((counter_actual + 1))
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## sets:
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## exiting_mode
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## existing_owner
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## existing_group
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output_stat "${file_name}"
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## -h file True if file is a symbolic Link.
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## -u file True if file has its set-user-id bit set.
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## -g file True if file has its set-group-id bit set.
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if test -h "${file_name}"; then
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## https://forums.whonix.org/t/disable-suid-binaries/7706/14
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log info "Skip symlink: '${file_name}'"
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continue
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fi
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if test -d "${file_name}"; then
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log info "Skip directory: '${file_name}'"
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continue
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fi
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local setuid setgid
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setuid=""
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if test -u "${file_name}"; then
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setuid=true
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fi
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setgid=""
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if test -g "${file_name}"; then
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setgid=true
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fi
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local setuid_or_setgid
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setuid_or_setgid=""
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if test "${setuid}" = "true" || test "${setgid}" = "true"; then
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setuid_or_setgid=true
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fi
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if test -z "${setuid_or_setgid}"; then
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log info "Neither setuid nor setgid. Skipping. file_name: '${file_name}'"
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continue
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fi
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## Remove suid / gid and execute permission for 'group' and 'others'.
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## Similar to: chmod og-ugx /path/to/filename
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## Removing execution permission is useful to make binaries such as 'su'
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## fail closed rather than fail open if suid was removed from these.
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## Do not remove read access since no security benefit and easier to
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## manually undo for users.
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## Are there suid or sgid binaries which are still useful if suid / sgid
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## has been removed from these?
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new_mode="744"
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local is_exact_whitelisted
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is_exact_whitelisted=""
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for white_list_entry in "${exact_white_list[@]:-}"; do
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if test -z "${white_list_entry}"; then
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log info "white_list_entry unset. Skipping. file_name: '${file_name}'"
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continue
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fi
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if test "${file_name}" = "${white_list_entry}"; then
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is_exact_whitelisted="true"
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log info "is_exact_whitelisted=true. Skipping. file_name: '${file_name}'"
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## Stop looping through the whitelist.
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break
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fi
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done
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local is_match_whitelisted
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is_match_whitelisted=""
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for matchwhite_list_entry in "${match_white_list[@]:-}"; do
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if test -z "${matchwhite_list_entry}"; then
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log info "matchwhite_list_entry unset. Skipping. file_name: '${file_name}'"
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continue
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fi
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if safe_echo "${file_name}" | grep --quiet --fixed-strings -- "${matchwhite_list_entry}"; then
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is_match_whitelisted="true"
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log info "is_match_whitelisted=true. Skipping. file_name: '${file_name}'"
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## Stop looping through the match_white_list.
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break
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fi
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done
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local is_disable_whitelisted
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is_disable_whitelisted=""
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for disablematch_list_entry in "${disable_white_list[@]:-}"; do
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if test -z "${disablematch_list_entry}"; then
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log info "disablematch_list_entry unset. Skipping. file_name: '${file_name}'"
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continue
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fi
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if safe_echo "${file_name}" | grep --quiet --fixed-strings -- "${disablematch_list_entry}"; then
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is_disable_whitelisted="true"
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log info "is_disable_whitelisted=true. Skipping. file_name: '${file_name}'"
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## Stop looping through the disablewhitelist.
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break
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fi
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done
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local clean_output_prefix clean_output
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clean_output_prefix="Managing (S|G)UID of line:"
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clean_output="${setuid:+setuid='true'} ${setgid:+setgid='true'} existing_mode='${existing_mode}' new_mode='${new_mode}' file='${file_name}'"
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if test "${whitelists_disable_all:-}" = "true"; then
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log info "${clean_output_prefix} whitelists_disable_all=true ${clean_output}"
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elif test "${is_disable_whitelisted}" = "true"; then
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log info "${clean_output_prefix} is_disable_whitelisted=true ${clean_output}"
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else
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if test "${is_exact_whitelisted}" = "true"; then
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log info "${clean_output_prefix} is_exact_whitelisted=true ${clean_output}"
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continue
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fi
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if test "${is_match_whitelisted}" = "true"; then
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log info "${clean_output_prefix} is_match_whitelisted=true matchwhite_list_entry='${matchwhite_list_entry}' ${clean_output}"
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continue
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fi
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fi
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log notice "${clean_output_prefix} ${clean_output}"
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# shellcheck disable=SC2086
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if dpkg-statoverride ${dpkg_admindir_parameter_existing_mode} --list "${file_name}" >/dev/null; then
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log info "Existing mode already saved previously. Not saving again."
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else
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## Save existing_mode in separate database.
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## Not using --update as not intending to enforce existing_mode.
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# shellcheck disable=SC2086
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echo_wrapper_audit silent dpkg-statoverride ${dpkg_admindir_parameter_existing_mode} --add "${existing_owner}" "${existing_group}" "${existing_mode}" "${file_name}"
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fi
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## No need to check "dpkg-statoverride --list" for existing entries.
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## If existing_mode was correct already, we would not have reached this
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## point. Since existing_mode is incorrect, remove from dpkg-statoverride
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## and re-add.
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## Remove from real database.
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echo_wrapper_ignore silent dpkg-statoverride --remove "${file_name}"
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## Remove from separate database.
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# shellcheck disable=SC2086
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echo_wrapper_ignore silent dpkg-statoverride ${dpkg_admindir_parameter_new_mode} --remove "${file_name}"
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## Add to real database and use --update to make changes on disk.
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echo_wrapper_audit verbose dpkg-statoverride --add --update "${existing_owner}" "${existing_group}" "${new_mode}" "${file_name}"
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## Not using --update as this is only for recording.
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# shellcheck disable=SC2086
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echo_wrapper_audit silent dpkg-statoverride ${dpkg_admindir_parameter_new_mode} --add "${existing_owner}" "${existing_group}" "${new_mode}" "${file_name}"
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done < <(safe_echo_nonewline "${fso_to_process}" | find -files0-from - -perm /u=s,g=s -print0)
|
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|
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## Sanity test.
|
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if test ! "${should_be_counter}" = "${counter_actual}"; then
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log info "File (parsed/wanted): '${fso_to_process}': (${counter_actual}/${should_be_counter})"
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log error "Expected number of files to be parsed was not met." >&2
|
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exit_code=202
|
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fi
|
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}
|
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|
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set_file_perms() {
|
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log info "START parsing config file: '${config_file}'"
|
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|
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local line
|
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while read -r line || test -n "${line}"; do
|
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if test -z "${line}"; then
|
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true "DEBUG: line is empty. Skipping."
|
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continue
|
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fi
|
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|
||||
if [[ "${line}" =~ ^\s*# ]]; then
|
||||
continue
|
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fi
|
||||
|
||||
if ! [[ "${line}" =~ [0-9a-zA-Z/] ]]; then
|
||||
exit_code=200
|
||||
log error "Line contains invalid characters: '${line}'" >&2
|
||||
## Safer to exit with error in this case.
|
||||
## https://forums.whonix.org/t/disable-suid-binaries/7706/59
|
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exit "${exit_code}"
|
||||
fi
|
||||
|
||||
if test "${line}" = 'whitelists_disable_all=true'; then
|
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whitelists_disable_all=true
|
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log info "whitelists_disable_all=true"
|
||||
continue
|
||||
fi
|
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|
||||
#global fso
|
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local mode_from_config owner_from_config group_from_config capability_from_config
|
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if ! read -r fso mode_from_config owner_from_config group_from_config capability_from_config <<<"${line}"; then
|
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exit_code=201
|
||||
log error "Cannot parse line: '${line}'" >&2
|
||||
## Debugging.
|
||||
du -hs /tmp || true
|
||||
safe_echo "test -w /tmp: '$(test -w /tmp)'" >&2 || true
|
||||
## Safer to exit with error in this case.
|
||||
## https://forums.whonix.org/t/disable-suid-binaries/7706/59
|
||||
exit "${exit_code}"
|
||||
fi
|
||||
|
||||
log info "Parsing line: fso='${fso}' mode_from_config='${mode_from_config}' owner_from_config='${owner_from_config}' group_from_config='${group_from_config}' capability_from_config='${capability_from_config}'"
|
||||
|
||||
## Debugging.
|
||||
#safe_echo "line: '${line}'"
|
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#safe_echo "fso: '${fso}'"
|
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#safe_echo "mode_from_config: '${mode_from_config}'"
|
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#safe_echo "owner_from_config: '${owner_from_config}'"
|
||||
|
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local fso_without_trailing_slash
|
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fso_without_trailing_slash="${fso%/}"
|
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|
||||
declare -g disable_white_list exact_white_list match_white_list
|
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case "${mode_from_config}" in
|
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disablewhitelist)
|
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disable_white_list+=("${fso}")
|
||||
continue
|
||||
;;
|
||||
exactwhitelist)
|
||||
exact_white_list+=("${fso}")
|
||||
continue
|
||||
;;
|
||||
matchwhitelist)
|
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match_white_list+=("${fso}")
|
||||
continue
|
||||
;;
|
||||
esac
|
||||
|
||||
if test ! -e "${fso}"; then
|
||||
log info "File does not exist: '${fso}'"
|
||||
continue
|
||||
fi
|
||||
|
||||
## Use dpkg-statoverride so permissions are not reset during upgrades.
|
||||
|
||||
if test "${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
|
||||
log error "Invalid mode: '${mode_from_config}'" >&2
|
||||
continue
|
||||
fi
|
||||
if test "${string_length_of_mode_from_config}" -lt "3"; then
|
||||
log error "Invalid mode: '${mode_from_config}'" >&2
|
||||
continue
|
||||
fi
|
||||
|
||||
if ! grep --quiet --fixed-strings -- "${owner_from_config}:" "${store_dir}/private/passwd"; then
|
||||
log error "Owner from config does not exist: '${owner_from_config}'" >&2
|
||||
continue
|
||||
fi
|
||||
|
||||
if ! grep --quiet --fixed-strings -- "${group_from_config}:" "${store_dir}/private/group"; then
|
||||
log error "Group from config does not exist: '${group_from_config}'" >&2
|
||||
continue
|
||||
fi
|
||||
|
||||
local mode_for_grep
|
||||
mode_for_grep="${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="${mode_from_config:1}"
|
||||
fi
|
||||
|
||||
file_name="${fso_without_trailing_slash}"
|
||||
|
||||
## sets:
|
||||
## exiting_mode
|
||||
## existing_owner
|
||||
## existing_group
|
||||
output_stat "${file_name}"
|
||||
|
||||
## Check there is an entry for the fso.
|
||||
##
|
||||
## example: dpkg-statoverride --list | grep /home
|
||||
## output:
|
||||
## root root 755 /home
|
||||
##
|
||||
## dpkg-statoverride does not show leading '0'.
|
||||
local dpkg_statoverride_list_output=""
|
||||
local dpkg_statoverride_list_exit_code=0
|
||||
dpkg_statoverride_list_output="$(dpkg-statoverride --list "${fso_without_trailing_slash}")" || {
|
||||
dpkg_statoverride_list_exit_code=$?
|
||||
true
|
||||
}
|
||||
|
||||
if test "${dpkg_statoverride_list_exit_code}" = "0"; then
|
||||
local grep_line
|
||||
grep_line="${owner_from_config} ${group_from_config} ${mode_for_grep} ${fso_without_trailing_slash}"
|
||||
if safe_echo "${dpkg_statoverride_list_output}" | grep --quiet --fixed-strings -- "${grep_line}"; then
|
||||
log info "The owner/group/mode matches fso entry. No further action required."
|
||||
else
|
||||
log info "The owner/group/mode does not match fso entry, updating entry."
|
||||
## 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
|
||||
log info "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_audit silent dpkg-statoverride ${dpkg_admindir_parameter_existing_mode} --add "${existing_owner}" "${existing_group}" "${existing_mode}" "${fso_without_trailing_slash}"
|
||||
fi
|
||||
|
||||
# shellcheck disable=SC2086
|
||||
echo_wrapper_ignore silent dpkg-statoverride ${dpkg_admindir_parameter_new_mode} --remove "${fso_without_trailing_slash}"
|
||||
|
||||
## Remove from and add to real database.
|
||||
echo_wrapper_ignore silent dpkg-statoverride --remove "${fso_without_trailing_slash}"
|
||||
echo_wrapper_audit verbose dpkg-statoverride --add --update "${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_audit silent dpkg-statoverride ${dpkg_admindir_parameter_new_mode} --add "${owner_from_config}" "${group_from_config}" "${mode_from_config}" "${fso_without_trailing_slash}"
|
||||
fi
|
||||
else
|
||||
log info "There is no fso entry, adding one."
|
||||
|
||||
# shellcheck disable=SC2086
|
||||
if dpkg-statoverride ${dpkg_admindir_parameter_existing_mode} --list "${fso_without_trailing_slash}" >/dev/null; then
|
||||
log info "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_audit silent dpkg-statoverride ${dpkg_admindir_parameter_existing_mode} --add "${existing_owner}" "${existing_group}" "${existing_mode}" "${fso_without_trailing_slash}"
|
||||
fi
|
||||
|
||||
## Add to real database.
|
||||
echo_wrapper_audit verbose dpkg-statoverride --add --update "${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_audit silent 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
|
||||
log info "capability_from_config is empty. Skipping. file_name: '${file_name}'"
|
||||
continue
|
||||
fi
|
||||
|
||||
if test "${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.
|
||||
##
|
||||
## NOTE: setcap does not support End-of-Options Marker ('--') yet.
|
||||
## setcap bug report:
|
||||
## setcap Command Does Not Support End-of-Options Marker ('--')
|
||||
## https://bugzilla.kernel.org/show_bug.cgi?id=219487
|
||||
echo_wrapper_ignore verbose setcap -r "${fso}"
|
||||
getcap_output="$(getcap -- "${fso}")"
|
||||
if test -n "${getcap_output}"; then
|
||||
exit_code=205
|
||||
log error "Removing capabilities failed. File: '${fso}'" >&2
|
||||
continue
|
||||
fi
|
||||
else
|
||||
if ! capsh --print | grep --fixed-strings -- "Bounding set" | grep --quiet -- "${capability_from_config}"; then
|
||||
log error "Capability from config does not exist: '${capability_from_config}'" >&2
|
||||
continue
|
||||
fi
|
||||
|
||||
## feature request: dpkg-statoverride: support for capabilities
|
||||
## https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=502580
|
||||
echo_wrapper_audit verbose setcap "${capability_from_config}+ep" -- "${fso}"
|
||||
fi
|
||||
|
||||
done <"${config_file}"
|
||||
log 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)"
|
||||
safe_echo "${passwd_file_contents_temp}" | tee -- "${store_dir}/private/passwd" >/dev/null
|
||||
group_file_contents_temp="$(getent group)"
|
||||
safe_echo "${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 \
|
||||
/usr/lib/permission-hardener.d/*.conf \
|
||||
/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
|
||||
|
||||
log notice "\
|
||||
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
|
||||
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
|
||||
true "DEBUG: Stat file does not exist, hardening was not applied before."
|
||||
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 <<< "${line}"; then
|
||||
exit_code=201
|
||||
log error "Cannot parse line: '${line}'" >&2
|
||||
continue
|
||||
fi
|
||||
log info "Parsing line: 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}" = "${file_name}"; then
|
||||
verbose="--verbose"
|
||||
remove_one=true
|
||||
safe_echo "${remove_one}" | tee -- "${store_dir}/remove_one" >/dev/null
|
||||
else
|
||||
safe_echo "false" | tee -- "${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}" "${file_name}" || exit_code=203
|
||||
else
|
||||
log info "File does not exist: '${file_name}'"
|
||||
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 "${store_dir}/remove_one")" = "false"; then
|
||||
log info "No file was removed.
|
||||
|
||||
File '${remove_file}' has not been removed from SUID Disabler and Permission Hardener during this invocation. This is expected if already done earlier.
|
||||
|
||||
This program expects the full path to the file. Example:
|
||||
$0 disable /usr/bin/newgrp # absolute path: works
|
||||
$0 disable newgrp # relative path: does not work
|
||||
|
||||
To remove all:
|
||||
$0 disable all
|
||||
|
||||
This change might not be permanent. For full instructions, see:
|
||||
https://www.kicksecure.com/wiki/SUID_Disabler_and_Permission_Hardener
|
||||
|
||||
To view list of changed by SUID Disabler and Permission Hardener:
|
||||
https://www.kicksecure.com/wiki/SUID_Disabler_and_Permission_Hardener#View_List_of_Permissions_Changed_by_SUID_Disabler_and_Permission_Hardener
|
||||
|
||||
For re-enabling any specific SUID binary:
|
||||
https://www.kicksecure.com/wiki/SUID_Disabler_and_Permission_Hardener#Re-Enable_Specific_SUID_Binaries
|
||||
|
||||
For completely disabling SUID Disabler and Permission Hardener:
|
||||
https://www.kicksecure.com/wiki/SUID_Disabler_and_Permission_Hardener#Disable_SUID_Disabler_and_Permission_Hardener"
|
||||
fi
|
||||
fi
|
||||
}
|
||||
|
||||
check_root(){
|
||||
if test "$(id -u)" != "0"; then
|
||||
log error "Not running as root, aborting."
|
||||
exit 1
|
||||
fi
|
||||
}
|
||||
|
||||
usage(){
|
||||
safe_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 "${exit_code}" != "0"; then
|
||||
log error "Exiting with non-zero exit code: '${exit_code}'" >&2
|
||||
fi
|
||||
|
||||
exit "${exit_code}"
|
||||
@ -10,5 +10,7 @@
|
||||
# user logins with `su` and KScreenLocker
|
||||
#
|
||||
# See also: https://www.kicksecure.com/wiki/SUID_Disabler_and_Permission_Hardener#passwd
|
||||
/usr/bin/passwd exactwhitelist
|
||||
/bin/passwd exactwhitelist
|
||||
/usr/bin/passwd 0755 root root
|
||||
/bin/passwd 0755 root root
|
||||
Loading…
x
Reference in New Issue
Block a user