archlinux-initrd-ssh-crypts.../src/hooks/ssh-cryptsetup

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#!/usr/bin/ash
. "/usr/local/bin/ssh-cryptsetup-tools"
sshcs_net_start() {
local iparg net_address ipconfig_out net_netmask net_gateway net_dns0 net_dns1
# we must have an 'ip' setting, and a device in it
[ -z "${ip}" ] && [ -n "${nfsaddrs}" ] && ip="${nfsaddrs}"
[ -z "${ip}" ] && {
dbg "No ip setting to setup network"
return 1
}
net_device=$(echo ${ip} | cut -d: -f6)
[ -z "${net_device}" ] && {
dbg "No network device to setup"
return 1
}
if [ "${sshcs_opt_net_wol:-d}" != "d" ]; then
dbg "Setting network device=${net_device} wol=${sshcs_opt_net_wol}"
ethtool -s "${net_device}" wol "${sshcs_opt_net_wol}"
fi
# Setup network and save some values
# Note: some useful redirection means ('< <(...)' and '<<< "$(...)"') are
# not supported in the available shell. So we have to write code in a
# temporary file and 'source' it since '... | while read ...' spawns a
# subshell from which outer variables cannot be altered.
: > "${net_env}"
echo ""
echo "Configuring IP (timeout = ${sshcs_opt_timeout_ipconfig}s) ..."
# ipconfig manual: https://git.kernel.org/pub/scm/libs/klibc/klibc.git/tree/usr/kinit/ipconfig/README.ipconfig
ipconfig_out=$(ipconfig -t "${sshcs_opt_timeout_ipconfig}" "ip=${ip}")
if [ $? -ne 0 ]; then
err "IP configuration timeout!"
echo "Devices probing:"
ipconfig -n -t 5 -c none all
return 1
fi
echo -n "${ipconfig_out}" | while read line; do
[ "${line#"IP-Config:"}" != "${line}" ] && continue
line="$(echo "${line}" | sed -e 's/ :/:/g;s/: /=/g')"
for iparg in ${line}; do
case "${iparg}" in
address=*|netmask=*|gateway=*|dns0=*|dns1=*)
echo "net_${iparg}" >> "${net_env}"
;;
esac
done
done
. "${net_env}"
rm -f "${net_env}"
echo "IP-Config: device=${net_device} ip=${net_address}/${net_netmask} gw=${net_gateway} dns0=${net_dns0} dns1=${net_dns1}"
[ -n "${net_address}" ]
}
sshcs_net_done() {
# we are done with the network
if [ -n "${net_device}" ]; then
dbg "Setting network device=${net_device} down"
ip addr flush dev "${net_device}"
ip link set dev "${net_device}" down
fi
}
sshcs_trapped_timeout() {
err "Timeout reached! Powering off."
poweroff -f
exit
}
sshcs_trap_timeout() {
local pid_init=$$
if [ ${sshcs_opt_timeout_poweroff} -gt 0 ]; then
echo ""
echo "WARNING! Automatic poweroff will be triggered in ${sshcs_opt_timeout_poweroff}s"
echo "To deactivate, please unlock devices"
trap sshcs_trapped_timeout SIGALRM
(
sleep ${sshcs_opt_timeout_poweroff}
kill -SIGALRM ${pid_init}
# Signal is not processed if cryptsetup is waiting for the password
killall cryptsetup > /dev/null 2>&1
) &
pid_timeout=$!
fi
}
sshcs_untrap_timeout() {
[ -z "${pid_timeout}" ] && return 0
# Notes:
# If there was a running SSH shell, it may also try to kill it.
# This only kills the spawned subshell, leaving the 'sleep' command still
# running until done (which is not an issue).
proc_parse_stat ${pid_timeout} && kill ${pid_timeout}
pid_timeout=
trap - SIGALRM
msg "Timeout cleared."
}
sshcs_shell_run() {
sshcs_trap_timeout
# actual script (shared with SSH login) with which we can unlock devices
sshcs_unlocked_test=0
. "${sshcs_shell_script}"
}
sshcs_dropbear_run() {
local pid_timeout=
local dev_pts_mounted=0
local listen=
# ensure /dev/pts is present
if [ ! -d "/dev/pts" ]; then
mkdir -p "/dev/pts"
mount -t devpts devpts "/dev/pts"
dev_pts_mounted=1
fi
if [ ${sshcs_opt_use_shell} -eq 0 ]; then
sshcs_shell_script=${sshcs_cryptsetup_script}
else
cat <<EOF > "${sshcs_shell_script}"
#!/usr/bin/ash
. "/usr/local/bin/ssh-cryptsetup-tools"
echo ""
echo "Call ${sshcs_cryptsetup_script} to try unlocking device(s)"
# Now give the user its shell
/usr/bin/ash
# Check whether we are fully done
sshcs_check_done 1
EOF
chmod a+x "${sshcs_shell_script}"
fi
# /etc/passwd file for the root user
echo "root:x:0:0:root:/root:${sshcs_shell_script}" > "/etc/passwd"
echo "${sshcs_shell_script}" > "/etc/shells"
[ ! -d "/var/log" ] && mkdir -p "/var/log"
touch "/var/log/lastlog"
msg "Starting dropbear ..."
dropbear -Esgjk -P "${path_dropbear_pid}" ${sshcs_opt_listen}
# Actual unlocking shell
sshcs_shell_run
}
sshcs_cryptpart_process() {
local cryptdev_orig cryptopt cryptargs
# ensure there is a device (handle 'UUID=' format)
[ -z "${cryptdev}" ] && return 0
[ "${cryptdev#UUID=}" != "${cryptdev}" ] && cryptdev="/dev/disk/by-uuid/${cryptdev#UUID=}"
# get crypt options
cryptargs=
for cryptopt in ${cryptoptions//,/ }; do
case ${cryptopt} in
discard)
cryptargs="${cryptargs} --allow-discards"
;;
luks)
;;
*)
echo "Device ${cryptdev} encryption option '${cryptopt}' not known, ignoring."
;;
esac
done
# ensure device is encrypted and handled
cryptdev_orig=${cryptdev}
if cryptdev=$(resolve_device "${cryptdev_orig}" ${rootdelay}); then
if cryptsetup isLuks "${cryptdev}" >/dev/null 2>&1; then
dbg "Adding crypt device=${cryptdev} type=${crypttype} name=${cryptname} args=<${cryptargs}> in setup script"
# update script used to unlock device either in console or SSH
[ -s "${sshcs_cryptsetup_script}" ] || cat <<'EOF' > "${sshcs_cryptsetup_script}"
#!/usr/bin/ash
. "/usr/local/bin/ssh-cryptsetup-tools"
cycle_or_retry() {
local res
read -n 1 -s -t 5 -p "Within 5s press 'P' to poweroff, 'R' to reboot or any other key to retry. " res
echo ""
[ "${res}" == "P" ] && poweroff -f
[ "${res}" == "R" ] && reboot -f
}
try_unlock() {
EOF
cat <<EOF >> "${sshcs_cryptsetup_script}"
# loop until device is available
while [ ! -e "/dev/mapper/${cryptname}" ]; do
if [ \${sshcs_unlocked_test:-0} -eq 1 ]; then
sshcs_unlocked=0
return
fi
if cryptsetup open --type "${crypttype}" "${cryptdev}" "${cryptname}" ${cryptargs} "\${CSQUIET}"; then
if poll_device "/dev/mapper/${cryptname}" ${rootdelay}; then
killall cryptsetup > /dev/null 2>&1
break
fi
err "Device still not mapped! Please wait or retry."
elif [ ! -e "/dev/mapper/${cryptname}" ]; then
err "cryptsetup failed! Please retry."
else
break
fi
cycle_or_retry
done
EOF
else
err "Failed to manage encrypted device ${cryptdev_orig}: not a LUKS volume."
fi
fi
}
sshcs_cryptpart_setup() {
local cryptdev crypttype cryptname cryptpass cryptoptions
# check encrypted devices to handle
cryptdev=
crypttype=luks
while read cryptname cryptdev cryptpass cryptoptions; do
# skip comment lines
[ "${cryptname:0:1}" = "#" ] && continue
# skip devices with given password
[ -n "${cryptpass}" ] && [ "${cryptpass}" != "none" ] && [ "${cryptpass}" != "-" ] && continue
sshcs_cryptpart_process
done < "${etc_crypttab}"
# Nothing else to do if there is no device we can unlock
[ -s "${sshcs_cryptsetup_script}" ] || return 0
cat <<'EOF' >> "${sshcs_cryptsetup_script}"
# No other device to unlock
}
if [ -c "/dev/mapper/control" ]; then
CSQUIET=
try_unlock
[ ${sshcs_unlocked_test:-0} -eq 1 ] && return
sshcs_check_done 0
else
if [ \${sshcs_unlocked_test:-0} -eq 1 ]; then
sshcs_unlocked=0
return
fi
echo ""
err "Device resources missing! Please retry."
fi
EOF
chmod a+x "${sshcs_cryptsetup_script}"
}
run_hook() {
local etc_crypttab="/etc/crypttab"
local path_dropbear_pid="/.dropbear.pid"
local sshcs_shell_script="/.sshcs_shell.sh"
local net_env="/.sshcs_net_env.sh"
local line net_device
local CSQUIET
# Note: options were loaded already
# sanity check: crypttab should be present
[ ! -e "${etc_crypttab}" ] && {
dbg "No crypttab configuration to process"
return 0
}
# Initialize random generator ASAP.
# May delay first SSH login by a few seconds otherwise.
(dd if=/dev/urandom of=/dev/null bs=4 count=1 status=none > /dev/null 2>&1) &
(dd if=/dev/random of=/dev/null bs=4 count=1 status=none > /dev/null 2>&1) &
modprobe -a -q dm-crypt >/dev/null 2>&1
[ "${quiet}" = "y" ] && CSQUIET=">/dev/null"
umask 0022
# Setup script used to unlock device either in console or SSH
sshcs_cryptpart_setup
if [ ! -e "${sshcs_cryptsetup_script}" ]; then
err "No encrypted device found! Skipping crypt remote unlocking."
return 0
fi
# start and check network
if ! sshcs_net_start; then
err "Net interface not available! Skipping crypt remote unlocking."
# We still allow to unlock locally with timeout
sshcs_shell_run
return 0
fi
# time to unlock (through console or dropbear)
sshcs_dropbear_run
}