Add info on how to fetch autosign key.

(GitHub issue #18)

.drone.yml

@@ -18,8 +18,10 @@ steps:
   commands:
   - rm /etc/apt/apt.conf.d/docker-clean
   - rm /var/cache/apt/archives/lock
+  - echo "APT::Default-Release \"stretch\";" >> /etc/apt/apt.conf.d/00default_release
+  - echo "deb http://deb.debian.org/debian buster main" >> /etc/apt/sources.list.d/buster.list
   - apt-get update -q
-  - apt-get install -qy shellcheck
+  - apt-get install -qy -t buster shellcheck
   - shellcheck hashboot
   volumes:
   - name: debian-package-cache

README.md

@@ -7,34 +7,44 @@ option to restore the file from backup.
 If there is a core- or libreboot BIOS and [flashrom](https://flashrom.org/)
 installed, **hashboot** can check the BIOS for modifications too.
 
+We moved our code to
+[schlomp.space](https://schlomp.space/tastytea/hashboot) but we keep the
+[GitHub-repo](https://github.com/tastytea/hashboot) as a mirror.
+
 # Install
 
 ## Packages
 
 ### Void Linux
 
-``` shellsession
+``` shell
 xbps-install -S hashboot
 ```
 
-### Gentoo
+### Gentoo Linux
 
 Ebuilds are available via the
 [tastytea repository](https://schlomp.space/tastytea/overlay).
 
-``` shellsession
+``` shell
 emerge -a sys-apps/hashboot
 rc-update add hashboot boot
 ```
 
-## Manual
-
 ### Arch Linux
 
-Go to [the Arch installation instructions](arch_instructions.md).
+Use the [package from AUR](https://aur.archlinux.org/packages/hashboot/).
+
+## Manual
 
 ### Any distro
 
+The releases on
+[schlomp.space](https://schlomp.space/tastytea/hashboot/releases) are
+PGP-signed. The key-ID is `F7301ADFC9ED262448C42B64242E5AC4DA587BF9`
+(`242E5AC4DA587BF9`). You can fetch it with `gpg --locate-key
+autosign@tastytea.de`.
+
 * Make hashboot executable
 * Place hashboot anywhere in ${PATH}
 * Install the appropriate init script

arch_instructions.md

@@ -1,87 +0,0 @@
-# Install hashboot on Arch Linux
-## Setting up hashboot
-
-1. Clone the git repository and enter the directory:
-
-   `git clone https://github.com/tastytea/hashboot.git && cd hashboot`
-
-2. Distribute the files to the proper paths:
-
-   PLEASE NOTE: it's important to know that when using symlinks it's important to NOT delete the original files. DO NOT DELETE THE HASHBOOT GIT FOLDER. If you move the hashboot git folder, you will need to re-link the files before the next boot. The *advantage* to using symlinks is that if the hashboot code on Github is updated, you can pull the changes and not have to re-copy the files.
-
-   If you don't want to use links and therefore want to be able to safely delete the hashboot git folder, replace `ln -sf` with `cp`.
-
-   1. `sudo ln -sf $(readlink -f hashboot) /usr/bin/hashboot`
-   2. `sudo ln -sf $(readlink -f init/systemd/emergency.service) /etc/systemd/system/emergency.service`
-   3. `sudo ln -sf $(readlink -f init/systemd/emergency.target) /etc/systemd/system/emergency.target`
-   4. `sudo ln -sf $(readlink -f init/systemd/hashboot.service) /etc/systemd/system/hashboot.service`
-
-3. Make the hashboot script executable:
-
-   `sudo chmod a+x /usr/bin/hashboot`
-
-4. Generate the configuration file and initial files:
-
-   `sudo hashboot index`
-
-## Setting up systemd
-Start the hashboot service on boot:
-
-`sudo systemctl enable hashboot.service`
-
-## Setting up the pacman hook
-You may need to first create the hook folder:
-
-`sudo mkdir -p /etc/pacman.d/hooks`
-
-Then make the hashboot hook file:
-
-`sudo nano /etc/pacman.d/hooks/99-hashboot.hook`
-
-It's important to prefix the file with "99-" because pacman will execute hooks in alphabetical order, and hashboot should be among the last to be executed. Likewise, it's important to suffix the file with ".hook" or pacman won't think it's an alpm hook.
-
-Give it the following contents:
-
-```
-[Trigger]
-Operation = Install
-Operation = Upgrade
-Operation = Remove
-Type = Package
-Target = *
-
-[Action]
-Description = Regenerating hashboot checksums...
-When = PostTransaction
-Exec = /usr/bin/hashboot index
-```
-
-Now when you install, upgrade, or remove any package, hashboot will generate new files.
-
-## Making sure hashboot runs at boot
-Immediately after booting, you can view the status of the hashboot service with the command
-
-`sudo systemctl status hashboot.service`
-
-It should print something like:
-
-```
-* hashboot.service - Check for changes made to the boot partition since shutting down
-   Loaded: loaded (/etc/systemd/system/hashboot.service; enabled; vendor preset: disabled)
-   Active: inactive (dead) since Sun 2019-05-12 09:27:48 PDT; 20s ago
-  Process: 1292 ExecStart=/sbin/hashboot check (code=exited, status=0/SUCCESS)
- Main PID: 1292 (code=exited, status=0/SUCCESS)>
- 
-May 12 09:27:47 hostname systemd[1]: Starting Check for changes made to the boot partition since shutting down...
-May 12 09:27:48 hostname systemd[1]: hashboot.service: Succeeded.
-May 12 09:27:48 hostname systemd[1]: Started Check for changes made to the boot partition since shutting down.
-```
-
-systemd prints the hashboot file as residing in `/sbin`, but that's because in Arch Linux (and many other distributions), `/bin` and `/sbin` are both symlinks to `/usr/bin`. You can verify this with `ls -l /sbin`.
-
-## Notes on pacman hooks
-Pacman uses [alpm hooks](https://www.archlinux.org/pacman/alpm-hooks.5.html) to facilitate triggering an operation after a file or package has been modified by pacman. System hooks are stored in the `/usr/share/libalpm/hooks` directory, but user hooks are stored in `/etc/pacman.d/hooks` (the directory might not be present on an unmodified Arch installation). 
-
-`hashboot index` *should* be ran after any modification to `/boot`. However, pacman will not trigger a hook that should be triggered if files are modified in `/boot` if the files modified in `/boot` are only modified in a separate hook and not by pacman itself; that is, if the initramfs is modified by a prior hook, a hashboot hook that should be triggered if files are modified in `/boot` is not properly triggered.
-
-Furthermore, upgrading a package like `btrfs-progs` can trigger an initramfs update. It would be possible to watch the linux modules folders (`/usr/lib/modules/*`), but libalpm does not search for changes in subfolders, and the kernel module folders are hardcoded to the kernel version (e.g. `/usr/lib/modules/5.1.9-arch1-1-ARCH/`), and change with each kernel update. Therefore, it is safest to generate a new hashboot index every time any package is installed, upgraded, or removed.

hashboot

@@ -12,6 +12,9 @@
 # If we meet some day, and you think this is nice, you can give us a hug.     #
 ###############################################################################
 
+# Disable warnings about $?.
+# shellcheck disable=SC2181
+
 VERSION="0.9.14"
 PATH="/bin:/usr/bin:/sbin:/usr/sbin:${PATH}"
 DIGEST_FILE=""
@@ -47,29 +50,31 @@ die ()
     rm -f "${DIGEST_FILE_TMP}" "${MBR_TMP}" "${BIOS_TMP}"
 
     [ -z "${2}" ] || echo "${2}" >&2
-    exit ${1}
+    exit "${1}"
 }
 
 write_hashes ()
 {
-    #Write header to ${1}
-    echo "#hashboot ${VERSION} - Algorithm: $(basename ${HASHER})" > ${1}
+    local file="${1}"
+    #Write header to ${file}
+    echo "#hashboot ${VERSION} - Algorithm: $(basename ${HASHER})" > "${file}"
 
-    if [ $((${CKMODES} & 001)) -ne 0 ]; then
+    if [ $((CKMODES & 001)) -ne 0 ]; then
         #copy mbr to file
         dd if=${MBR_DEVICE} of=${MBR_TMP} bs=${MBR_SIZE}K count=1 status=${DD_STATUS} || die 8
-        #Write hash of MBR to ${1}
-        ${HASHER} ${MBR_TMP} >> ${1}
+        #Write hash of MBR to ${file}
+        ${HASHER} ${MBR_TMP} >> "${file}"
     fi
-    if [ $((${CKMODES} & 010)) -ne 0 ]; then
-        #Write hashes of all regular files to ${1}
-        find /boot -type f -exec ${HASHER} --binary {} >> ${1} +
+    if [ $((CKMODES & 010)) -ne 0 ]; then
+        #Write hashes of all regular files to ${file}
+        # shellcheck disable=SC2227
+        find /boot -type f -exec ${HASHER} --binary {} >> "${file}" +
     fi
-    if [ $((${CKMODES} & 100)) -ne 0 ]; then
+    if [ $((CKMODES & 100)) -ne 0 ]; then
         #read bios to file
         flashrom --programmer ${PROGRAMMER} -r ${BIOS_TMP} > /dev/null 2>&1
-        #and write hashes of bios files to ${1}
-        ${HASHER} ${BIOS_TMP} >> ${1}
+        #and write hashes of bios files to ${file}
+        ${HASHER} ${BIOS_TMP} >> "${file}"
 
     fi
 }
@@ -89,7 +94,9 @@ then
 fi
 
 # Debian < 8 check
-if which lsb_release > /dev/null 2>&1 && [ "$(lsb_release -si)" == "Debian" ] && [ $(lsb_release -sr | cut -d'.' -f1) -lt 8 ]
+if command -v lsb_release > /dev/null \
+        && [ "$(lsb_release -si)" == "Debian" ] \
+        && [ "$(lsb_release -sr | cut -d'.' -f1)" -lt 8 ]
 then
     DD_STATUS="noxfer"
 fi
@@ -97,9 +104,10 @@ fi
 #Look for config file and set ${MBR_DEVICE}.
 if [ -f ${CONFIG_FILE} ]
 then
+    # shellcheck source=/dev/null
     source ${CONFIG_FILE} || die 9 "Error reading config file"
     #compatibility to old cfg format
-    if [ ! -z "${BACKUP_FILE}" ]; then
+    if [ -n "${BACKUP_FILE}" ]; then
         SAVEDIR="/var/lib/hashboot"
         echo "SAVEDIR=${SAVEDIR}" >> ${CONFIG_FILE}
         mkdir -p ${SAVEDIR}
@@ -132,11 +140,11 @@ else
         echo "010=files"
         echo "100=core-/libreboot bios"
         echo "eg. 101 for mbr and bios: "
-        read CKMODES
+        read -r CKMODES
         echo "#001=mbr,010=files,100=bios" >> ${CONFIG_FILE}
         echo "CKMODES=$CKMODES" >> ${CONFIG_FILE}
 
-        if [ $((${CKMODES} & 001)) -ne 0 ]; then
+        if [ $((CKMODES & 001)) -ne 0 ]; then
             echo -n "Which device contains the MBR? [/dev/sda] "
             read -r MBR_DEVICE
             [ -z "${MBR_DEVICE}" ] && MBR_DEVICE="/dev/sda"
@@ -144,12 +152,12 @@ else
             echo "MBR_DEVICE=${MBR_DEVICE}" >> ${CONFIG_FILE}
         fi
 
-        if [ $((${CKMODES} & 100)) -ne 0 ]; then
-            if ! which flashrom; then
+        if [ $((CKMODES & 100)) -ne 0 ]; then
+            if ! command -v flashrom > /dev/null; then
                 echo "You need to have flashrom installed!"
                 echo "Currently it is not installed, don't reboot"
                 echo "If you need another programmer than internal"
-                echo "use the variable PROGRAMMER in $CONFIG_FILE\!"
+                echo "use the variable PROGRAMMER in ${CONFIG_FILE}!"
             fi
         fi
 
@@ -158,7 +166,7 @@ else
     fi
 fi
 
-if [ $((${CKMODES} & 001)) -ne 0 ]; then
+if [ $((CKMODES & 001)) -ne 0 ]; then
     # Find out where the first partition starts and set ${MBR_SIZE} in KiB
     sectorsize=$(LC_ALL=C fdisk -l ${MBR_DEVICE} | grep '^Units' | awk '{print $8}' )
     if [ "${sectorsize}" == "=" ] # Older versions of util-linux
@@ -171,7 +179,7 @@ if [ $((${CKMODES} & 001)) -ne 0 ]; then
         startsector=$(LC_ALL=C fdisk -l ${MBR_DEVICE} | grep -A1 'Device' | tail -n1 | awk '{print $3}' )
     fi
 
-    MBR_SIZE=$(expr ${sectorsize} \* ${startsector} / 1024)
+    MBR_SIZE=$((sectorsize * startsector / 1024))
 
     if [ ${?} != 0 ]
     then
@@ -183,10 +191,10 @@ fi
 if [ "${1}" == "index" ]
 then
     #Try different hashers, use the most secure
-    HASHER=$(/usr/bin/which sha512sum 2> /dev/null)
-    test -z "${HASHER}" && HASHER=$(/usr/bin/which sha384sum 2> /dev/null)
-    test -z "${HASHER}" && HASHER=$(/usr/bin/which sha256sum 2> /dev/null)
-    test -z "${HASHER}" && HASHER=$(/usr/bin/which sha224sum 2> /dev/null)
+    HASHER=$(command -v sha512sum)
+    test -z "${HASHER}" && HASHER=$(command -v sha384sum)
+    test -z "${HASHER}" && HASHER=$(command -v sha256sum)
+    test -z "${HASHER}" && HASHER=$(command -v sha224sum)
     #If we found no hasher: exit
     [ -z "${HASHER}" ] && die 5 "No hash calculator found"
 
@@ -205,11 +213,11 @@ then
             for file in $(diff ${DIGEST_FILE} ${DIGEST_FILE_TMP} | grep -v '#hashboot' | grep '<' | cut -d'*' -f2 | sed 's/\ /\\ /g' );
             do
                 #delete from tar
-                tar --delete -v -P -f $BACKUP_FILE $file
+                tar --delete -v -P -f ${BACKUP_FILE} "${file}"
             done
             for file in $(diff ${DIGEST_FILE} ${DIGEST_FILE_TMP} | grep -v '#hashboot' | grep '>' | cut -d'*' -f2 | sed 's/\ /\\ /g' );
             do
-                tar -r -v -P -f $BACKUP_FILE $file
+                tar -r -v -P -f $BACKUP_FILE "${file}"
             done
         fi
     #nur, wenn das updaten des Backups geklappt hat. *im Hinterkopf behalt*
@@ -231,28 +239,28 @@ elif [ "${1}" == "check" ]
 then
     [ -f ${DIGEST_FILE} ] || die 9 "No digestfile"
     HASHER=$(head -n1 ${DIGEST_FILE} | awk '{print $5}')
-    if [ $((${CKMODES} & 001)) != 0 ]; then
+    if [ $((CKMODES & 001)) != 0 ]; then
         dd if=${MBR_DEVICE} of=${MBR_TMP} bs=${MBR_SIZE}K count=1 status=${DD_STATUS} || die 8
         grep ${MBR_TMP} ${DIGEST_FILE} | ${HASHER} --check --warn --quiet --strict | tee ${LOG_FILE}
-        if [ ${PIPESTATUS[2]} -ne 0 ]
+        if [ "${PIPESTATUS[2]}" -ne 0 ]
         then
             echo "    !! TIME TO PANIK: MBR WAS MODIFIED !!"
             COUNTER=$((COUNTER + 1))
         fi
     fi
-    if [ $((${CKMODES} & 010)) -ne 0 ]; then
+    if [ $((CKMODES & 010)) -ne 0 ]; then
         grep -v ${MBR_TMP} ${DIGEST_FILE} | grep -v ${BIOS_TMP} | ${HASHER} --check --warn --quiet --strict | tee -a ${LOG_FILE}
-        if [ ${PIPESTATUS[2]} -ne 0 ]
+        if [ "${PIPESTATUS[2]}" -ne 0 ]
         then
             echo "    !! TIME TO PANIK: AT LEAST 1 FILE WAS MODIFIED !!"
             COUNTER=$((COUNTER + 2))
         fi
     fi
-    if [ $((${CKMODES} & 100)) -ne 0 ]; then
+    if [ $((CKMODES & 100)) -ne 0 ]; then
         flashrom --programmer ${PROGRAMMER} -r ${BIOS_TMP} > /dev/null 2>&1
         #if we set an programmer chip in config, find line with hash for bios and compare. if smthg wrong, panic
         grep ${BIOS_TMP} ${DIGEST_FILE} | ${HASHER} --check --warn --quiet --strict | tee -a ${LOG_FILE}
-        if [ ${PIPESTATUS[2]} -ne 0 ]
+        if [ "${PIPESTATUS[2]}" -ne 0 ]
         then
             echo "    !! TIME TO PANIK: BIOS WAS MODIFIED !!"
             COUNTER=$((COUNTER + 10))
@@ -268,15 +276,16 @@ then
     echo "Restoring files from backup... (type yes or no for each file)"
 
     #For each failed file: ask if it should be recovered from backup
+    # shellcheck disable=2013
     for file in $(cut -d: -f1 ${LOG_FILE})
     do
-        tar -xpPvwf ${BACKUP_FILE} ${file}
-        [ $? != 0 ] && echo "Error restoring ${file} from backup, continuing" >&2
+        tar -xpPvwf ${BACKUP_FILE} "${file}"
+        [ ${?} != 0 ] && echo "Error restoring ${file} from backup, continuing" >&2
         #If the MBR is to be recovered, copy to ${MBR_DEVICE}
         if [ "${file}" == ${MBR_TMP} ]
         then
             cp ${MBR_TMP} ${MBR_DEVICE}
-            [ $? != 0 ] && echo "Error restoring MBR from backup, continuing" >&2
+            [ ${?} != 0 ] && echo "Error restoring MBR from backup, continuing" >&2
         fi
     done
 else