mirror of
https://github.com/tasket/Qubes-VM-hardening.git
synced 2024-12-17 20:14:25 -05:00
240 lines
7.4 KiB
Bash
Executable File
240 lines
7.4 KiB
Bash
Executable File
#!/bin/sh
|
|
|
|
## Protect startup of Qubes VMs from /rw content ##
|
|
## https://github.com/tasket/Qubes-VM-hardening ##
|
|
## Copyright 2017-2019 Christopher Laprise ##
|
|
## tasket@protonmail.com ##
|
|
|
|
# This file is part of Qubes-VM-hardening.
|
|
# Qubes-VM-hardening is free software: you can redistribute it and/or modify
|
|
# it under the terms of the GNU General Public License as published by
|
|
# the Free Software Foundation, either version 3 of the License, or
|
|
# (at your option) any later version.
|
|
#
|
|
# Qubes-VM-hardening is distributed in the hope that it will be useful,
|
|
# but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
# GNU General Public License for more details.
|
|
#
|
|
# You should have received a copy of the GNU General Public License
|
|
# along with Qubes-VM-hardening. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
|
|
# Source Qubes library.
|
|
. /usr/lib/qubes/init/functions
|
|
|
|
# Define sh, bash, X and desktop init scripts in /home/user
|
|
# to be protected
|
|
chfiles=${chfiles:-".bashrc .bash_profile .bash_login .bash_logout .profile \
|
|
.xprofile .xinitrc .xserverrc .xsession"}
|
|
chdirs=${chdirs:-"bin .local/bin .config/autostart .config/plasma-workspace/env \
|
|
.config/plasma-workspace/shutdown .config/autostart-scripts .config/systemd"}
|
|
|
|
vmname=`qubesdb-read /name`
|
|
dev=/dev/xvdb
|
|
rw=/mnt/rwtmp
|
|
rwbak=$rw/vm-boot-protect
|
|
errlog=/var/run/vm-protect-error
|
|
defdir=/etc/default/vms
|
|
version="0.8.5"
|
|
|
|
|
|
# Remount fs as read-write
|
|
remount_rw() {
|
|
# Begin write operations
|
|
if [ -e $dev ] && mount -o remount,rw $dev $rw ; then
|
|
echo Good rw remount.
|
|
else
|
|
abort_startup RELOCATE "Remount failed!"
|
|
fi
|
|
}
|
|
|
|
|
|
# Function: Make user scripts immutable.
|
|
make_immutable() {
|
|
remount_rw
|
|
#initialize_home $rw/home ifneeded
|
|
cd $rw/home/user
|
|
mkdir -p $chdirs
|
|
touch $chfiles
|
|
chattr -R -f +i $chfiles $chdirs
|
|
cd /root
|
|
}
|
|
|
|
|
|
# Start rescue shell then exit/fail
|
|
abort_startup() {
|
|
type="$1"
|
|
msg="$2"
|
|
echo "$msg" >>$errlog
|
|
cat $errlog
|
|
|
|
rc=1
|
|
if [ $type = "RELOCATE" ]; then
|
|
# quarantine private volume
|
|
umount $dev
|
|
mv -f $dev /dev/badxvdb
|
|
truncate --size=500M /root/dev-xvdb
|
|
loop=`losetup --find --show /root/dev-xvdb`
|
|
mv -f $loop $dev
|
|
elif [ $type = "OK" ]; then
|
|
# allow normal start with private vol
|
|
rc=0
|
|
fi
|
|
|
|
# insert status msg and run xterm
|
|
cat /etc/bashrc /etc/bash.bashrc >/etc/bashrc-insert
|
|
echo "echo '** VM-BOOT-PROTECT SERVICE SHELL'" >/etc/bashrc
|
|
if [ $type = "RELOCATE" ]; then
|
|
echo "echo '** Private volume is located at /dev/badxvdb'" >>/etc/bashrc
|
|
fi
|
|
echo "cat $errlog" >>/etc/bashrc
|
|
echo ". /etc/bashrc-insert" >>/etc/bashrc
|
|
ln -f /etc/bashrc /etc/bash.bashrc
|
|
echo '/usr/bin/nohup /usr/bin/xterm /bin/bash 0<&- &>/dev/null &' \
|
|
>/etc/X11/Xsession.d/98rescue
|
|
|
|
exit $rc
|
|
}
|
|
|
|
|
|
echo >$errlog # Clear
|
|
|
|
if qsvc vm-boot-protect-cli; then
|
|
abort_startup RELOCATE "CLI requested."
|
|
fi
|
|
|
|
if qsvc vm-boot-protect || qsvc vm-boot-protect-root; then
|
|
# Mount private volume in temp location
|
|
mkdir -p $rw
|
|
if [ -e $dev ] && mount -o ro $dev $rw ; then
|
|
echo "Good read-only mount."
|
|
else
|
|
echo "Mount failed."
|
|
# decide if this is initial boot or a bad volume
|
|
private_size_512=$(blockdev --getsz "$dev")
|
|
if head -c $(( private_size_512 * 512 )) /dev/zero | diff "$dev" - >/dev/null; then
|
|
touch /var/run/qubes/VM-BOOT-PROTECT-INITIALIZERW
|
|
abort_startup OK "FIRST BOOT INITIALIZATION: PLEASE RESTART VM!"
|
|
else
|
|
abort_startup RELOCATE "Mount failed; BAD private volume!"
|
|
fi
|
|
fi
|
|
|
|
# Don't bother with root protections in template or standalone
|
|
if ! is_rwonly_persistent; then
|
|
if qsvc vm-boot-protect; then
|
|
make_immutable
|
|
fi
|
|
exit 0
|
|
fi
|
|
|
|
fi
|
|
|
|
|
|
# Protection measures for /rw dirs:
|
|
# Activated by presence of vm-boot-protect-root Qubes service.
|
|
# * Hashes in vms/vms.all.SHA and vms/$vmname.SHA files will be checked.
|
|
# * Remove /rw root startup files (config, usrlocal, bind-dirs).
|
|
# * Contents of vms/vms.all and vms/$vmname folders will be copied.
|
|
privdirs=${privdirs:-"/rw/config /rw/usrlocal /rw/bind-dirs"}
|
|
|
|
if qsvc vm-boot-protect-root && is_rwonly_persistent; then
|
|
|
|
# Check hashes
|
|
checkcode=0
|
|
if [ -e $defdir/$vmname.SHA ]; then
|
|
# remove padding and add number field
|
|
sed 's/^ *//; s/ *$//; /^$/d; s/^/1 /' $defdir/$vmname.SHA \
|
|
>/tmp/vm-boot-protect-sha
|
|
fi
|
|
if [ -e $defdir/vms.all.SHA ]; then
|
|
sed 's/^ *//; s/ *$//; /^$/d; s/^/2 /' $defdir/vms.all.SHA \
|
|
>>/tmp/vm-boot-protect-sha
|
|
fi
|
|
if [ -e /tmp/vm-boot-protect-sha ]; then
|
|
echo "Checking file hashes." |tee $errlog
|
|
# Get unique paths, remove field and switch path to $rw before check;
|
|
# this allows hashes in $vmname.SHA to override ones in vms.all.SHA.
|
|
sort --unique --key=3 /tmp/vm-boot-protect-sha \
|
|
| sed -r 's|^[1-2] (.*[[:space:]]*)/rw|\1'$rw'|' \
|
|
| sha256sum --strict -c >>$errlog; checkcode=$?
|
|
fi
|
|
|
|
# Divert startup on hash mismatch:
|
|
if [ $checkcode != 0 ]; then
|
|
abort_startup RELOCATE "Hash check failed!"
|
|
fi
|
|
|
|
remount_rw
|
|
|
|
# Files mutable for del/copy operations
|
|
cd $rw/home/user
|
|
chattr -R -f -i $chfiles $chdirs $privdirs
|
|
cd /root
|
|
|
|
|
|
# Deactivate private.img config dirs
|
|
mkdir -p $rwbak
|
|
for dir in $privdirs; do # maybe use 'eval' for privdirs quotes/escaping
|
|
echo "Deactivate $dir"
|
|
subdir=`echo $dir |sed -r 's|^/rw/||'`
|
|
bakdir="$rwbak/BAK-$subdir"
|
|
origdir="$rwbak/ORIG-$subdir"
|
|
if [ -d "$bakdir" ] && [ ! -d "$origdir" ]; then
|
|
mv "$bakdir" "$origdir"
|
|
fi
|
|
rm -rf "$bakdir"
|
|
mv "$rw/$subdir" "$bakdir"
|
|
mkdir -p "$rw/$subdir"
|
|
done
|
|
|
|
for vmset in vms.all $vmname; do
|
|
|
|
# Process whitelists...
|
|
cat $defdir/$vmset.whitelist \
|
|
| while read wlfile; do
|
|
# Must begin with '/rw/'
|
|
if echo $wlfile |grep -q "^\/rw\/"; then
|
|
srcfile="`echo $wlfile |sed -r \"s|^/rw/(.+)$|$rwbak/BAK-\1|\"`"
|
|
dstfile="`echo $wlfile |sed -r \"s|^/rw/(.+)$|$rw/\1|\"`"
|
|
dstdir="`dirname \"$dstfile\"`"
|
|
if [ ! -e "$srcfile" ]; then
|
|
echo "Whitelist entry not present in filesystem:"
|
|
echo "$srcfile"
|
|
continue
|
|
# For very large dirs: mv whole dir when entry ends with '/'
|
|
elif echo $wlfile |grep -q "\/$"; then
|
|
echo "Whitelist mv $srcfile"
|
|
echo "to $dstfile"
|
|
mkdir -p "$dstdir"
|
|
mv -T "$srcfile" "$dstfile"
|
|
else
|
|
echo "Whitelist cp $srcfile"
|
|
mkdir -p "$dstdir"
|
|
cp -a --link "$srcfile" "$dstdir"
|
|
fi
|
|
elif [ -n "$wlfile" ]; then
|
|
echo "Whitelist path must begin with /rw/. Skipped."
|
|
fi
|
|
done
|
|
|
|
# Copy default files...
|
|
if [ -d $defdir/$vmset/rw ]; then
|
|
echo "Copy files from $defdir/$vmset/rw"
|
|
cp -af $defdir/$vmset/rw/* $rw
|
|
fi
|
|
done
|
|
|
|
fi
|
|
|
|
# Keep configs invisible at runtime...
|
|
rm -rf "$defdir"
|
|
|
|
if qsvc vm-boot-protect || qsvc vm-boot-protect-root; then
|
|
make_immutable
|
|
umount $rw
|
|
fi
|
|
|
|
exit 0
|