zfs/contrib/dracut/90zfs/zfs-load-key.sh.in

#!/bin/sh

# only run this on systemd systems, we handle the decrypt in mount-zfs.sh in the mount hook otherwise
[ -e /bin/systemctl ] || return 0

# This script only gets executed on systemd systems, see mount-zfs.sh for non-systemd systems

# import the libs now that we know the pool imported
[ -f /lib/dracut-lib.sh ] && dracutlib=/lib/dracut-lib.sh
[ -f /usr/lib/dracut/modules.d/99base/dracut-lib.sh ] && dracutlib=/usr/lib/dracut/modules.d/99base/dracut-lib.sh
# shellcheck source=./lib-zfs.sh.in
. "$dracutlib"

# load the kernel command line vars
[ -z "$root" ] && root="$(getarg root=)"
# If root is not ZFS= or zfs: or rootfstype is not zfs then we are not supposed to handle it.
[ "${root##zfs:}" = "${root}" ] && [ "${root##ZFS=}" = "${root}" ] && [ "$rootfstype" != "zfs" ] && exit 0

# There is a race between the zpool import and the pre-mount hooks, so we wait for a pool to be imported
while [ "$(zpool list -H)" = "" ]; do
    systemctl is-failed --quiet zfs-import-cache.service zfs-import-scan.service && exit 1
    sleep 0.1s
done

# run this after import as zfs-import-cache/scan service is confirmed good
# we do not overwrite the ${root} variable, but create a new one, BOOTFS, to hold the dataset
if [ "${root}" = "zfs:AUTO" ] ; then
    BOOTFS="$(zpool list -H -o bootfs | awk '$1 != "-" {print; exit}')"
else
    BOOTFS="${root##zfs:}"
    BOOTFS="${BOOTFS##ZFS=}"
fi

# if pool encryption is active and the zfs command understands '-o encryption'
if [ "$(zpool list -H -o feature@encryption "$(echo "${BOOTFS}" | awk -F/ '{print $1}')")" = 'active' ]; then
    # if the root dataset has encryption enabled
    ENCRYPTIONROOT="$(zfs get -H -o value encryptionroot "${BOOTFS}")"
    # where the key is stored (in a file or loaded via prompt)
    KEYLOCATION="$(zfs get -H -o value keylocation "${ENCRYPTIONROOT}")"
    if ! [ "${ENCRYPTIONROOT}" = "-" ]; then
        KEYSTATUS="$(zfs get -H -o value keystatus "${ENCRYPTIONROOT}")"
        # continue only if the key needs to be loaded
        [ "$KEYSTATUS" = "unavailable" ] || exit 0
        # if key is stored in a file, do not prompt
        if ! [ "${KEYLOCATION}" = "prompt" ]; then
            zfs load-key "${ENCRYPTIONROOT}"
        else
            # decrypt them
            TRY_COUNT=5
            while [ $TRY_COUNT -gt 0 ]; do
                systemd-ask-password "Encrypted ZFS password for ${BOOTFS}" --no-tty | zfs load-key "${ENCRYPTIONROOT}" && break
                TRY_COUNT=$((TRY_COUNT - 1))
            done
        fi
    fi
fi