diskimage-builder/elements/dpkg/extra-data.d/01-copy-apt-keys
Ian Wienand 672705831f Add a best-effort sudo safety check
As motivation for this; we have had two breakouts of dib in recent
memory.  One was a failure to unmount through symlinks in the core
code (I335316019ef948758392b03e91f9869102a472b9) and the other was
removing host keys on the build-system
(Ib01d71ff9415a0ae04d963f6e380aab9ac2260ce).

For the most part, dib runs unprivileged.  Bits of the core code are
hopefully well tested (modulo bugs like the first one!).  We give free
reign inside the chroot (although there is still some potential there
for adverse external affects via bind mounts).  Where we could be a
bit safer (and could have prevented at least the second of these
breakouts) is with some better checking that the "sudo" calls
*outside* the chroot at least looked sane.

This adds a basic check that we're using chroot or image paths when
calling sudo in those parts of elements that run *outside* the chroot.
Various files are updated to accomodate this check; mostly by just
ignoring it for existing code (I have not audited these calls).

Nobody is pretending this type of checking makes dib magically safe,
or removes the issues with it needing to do things as root during the
build.  But this can help find egregious errors like the key removal.

Change-Id: I161a5aea1d29dcdc7236f70d372c53246ec73749
2016-05-09 15:41:38 +10:00

40 lines
1.1 KiB
Bash
Executable File

#!/bin/bash
#
# Copyright 2014 Hewlett-Packard Development Company, L.P.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
if [ ${DIB_DEBUG_TRACE:-0} -gt 0 ]; then
set -x
fi
set -eu
set -o pipefail
DIB_ADD_APT_KEYS=${DIB_ADD_APT_KEYS:-""}
if [ -z "${DIB_ADD_APT_KEYS}" ]; then
echo "DIB_ADD_APT_KEYS is not set - not importing keys"
exit 0
fi
DIR=${TMP_MOUNT_PATH}/tmp/apt_keys
if [ -e ${DIR} ]; then
echo "${DIR} already exists!"
exit 1
fi
sudo mkdir -p ${DIR} # dib-lint: safe_sudo
# Copy to DIR
for KEY in $(find ${DIB_ADD_APT_KEYS} -type f); do
sudo cp -L ${KEY} ${DIR} # dib-lint: safe_sudo
done