1 files changed, 47 insertions, 62 deletions

diff --git a/crypttab b/crypttab
index 706e2f1..855cacc 100755
--- a/crypttab
+++ b/crypttab
@@ -1,4 +1,7 @@
 #!/usr/bin/env bash
+set -euo pipefail
+export IFS=$'\n\t'
+
 #
 # A script that handles basic crypttab functionality to mount encrypted volumes
 # on execution.
@@ -6,106 +9,88 @@
 
 TAB=/etc/crypttab
 
-#
 # Iterrates through all entries in crypttab with the purpose to close the
 # decrypted block devices (typically at /dev/mapper/*).
 #
 # NOTE: If any of the listed encrypted devices are mounted, attempts to umount
 # them first, since not doing so will cause the luksClose to hang.
-#
-function destroy_entries {
-  if [[ ! -f ${TAB} ]]; then
-    echo "Could not access ${TAB}."
+destroy_entries() {
+  local dev=''
+  if [ ! -f "${TAB}" ]; then
+    printf 'Could not access %s.\n' "${TAB}"
     exit 1
   fi
 
   # For each entry in crypttab
-  while read entry; do
-    local name=${entry%% *}
-
-    # Unmount all mountpoins if mounted anywhere
-    # Cryptsetup luksClose will repeatedly fail if the devices is mounted
-    # anywhere, causing shutdowns to hang up.
-    for i in "$(mount | grep /dev/mapper/${name})"; do
-      local mntpoint=$(echo ${i} | tr -s ' ' | cut -d ' ' -f 3)
-      # Skip if empty
-      [[ ${mntpoint} == '' ]] && continue
+  for entry in "$(grep -v -e '^#' -e '^ *$' ${TAB})"; do
+    dev="${entry%% *}"
+    mount="${entry##* }"
+    mapper="${dev////_}"
 
-      echo "${name} mounted at ${mntpoint}. Unmounting"
+    printf '%s mounted at %s. Unmounting\n' "${dev}" "${mount}"
 
-      # Kill any running processes accessing mntpoint
+    # Kill any running processes accessing mount point if lsof is available
+    if type lsof 2>/dev/null 1>/dev/null; then
       for pid in $(lsof -t ${mntpoint}); do
         pidstr=$(ps -f ${pid} | tail -n 1)
-        echo "Halting ${pid} ${pidstr##* }"
-        kill ${pid}
+        printf 'Halting %s %d\n' "${pid}" "${pidstr##* }"
+        kill "${pid}"
       done
+    fi
 
-      # Unmount
-      umount ${mntpoint}
-    done
+    umount -R "${mount}" || :
 
-    cryptsetup luksClose ${name}
-  done < "${TAB}"
+    printf 'Closing cryptdevice %s (%s)\n' "${dev}" "${mapper}"
+    cryptsetup luksClose "${mapper}"
+  done
 }
 
 
-#
 # Checks each device listed in the crypttab file for its current status
 # (encrypted, or decrypted).
-#
-function stat_entries {
-  local _name # Name of the mount
-  local _dev  # Device to be decrypted
-  if [[ ! -f ${TAB} ]]; then
-    echo "Could not access ${TAB}."
+stat_entries() {
+  if [ ! -f "${TAB}" ]; then
+    printf 'Could not access %s.\n' "${TAB}"
     exit 1
   fi
 
   # For each entry in crypttab
-  while read line; do
-    _name=$(echo ${line} | tr -s ' ' | cut -d ' ' -f 1)
-    _dev=$(echo ${line} | tr -s ' ' | cut -d ' ' -f 2)
+  for entry in "$(grep -v -e '^#' -e '^ *$' ${TAB})"; do
+    dev="${entry%% *}"
+    mapper="${dev////_}"
 
-    if [[ -L /dev/mapper/${_name} ]]; then
-      echo "${_name} (${_dev}) decrypted at /dev/mapper/${_name}"
+    if [ -L "/dev/mapper/${mapper}" ]; then
+      printf '%s decrypted at /dev/mapper/%s\n' "${dev}" "${mapper}"
     else
-      echo "${_name} (${_dev}) not decrypted."
+      printf '%s not decrypted\n' "${_dev}"
     fi
   done < "${TAB}"
 }
 
-#
 # Decrypts each encrypted device listed in crypttab
-#
-function setup_entries {
-  local _name # Name of the encrypted mount
-  local _dev  # Encrypted device path
-  local _key  # Encryption key to decrypt the device with
-
-  if [[ ! -f ${TAB} ]]; then
-    echo "Could not access ${TAB}."
+setup_entries() {
+  if [ ! -f "${TAB}" ]; then
+    printf 'Could not access %s.\n' "${TAB}"
     exit 1
   fi
 
-  while read entry; do
-    _name=$(echo ${entry} | tr -s ' ' | cut -d ' ' -f 1)
-    _dev=$(echo ${entry} | tr -s ' ' | cut -d ' ' -f 2)
-    _key=$(echo ${entry} | tr -s ' ' | cut -d ' ' -f 3)
-
-    # Skip any devices that are already decrypted
-    if [ -b "/dev/mapper/${_name}" ]; then
-      printf "Device ${_dev} already decrypted at /dev/mapper/${_name}.\n"
-      continue
-    fi
-    echo "Decrypting ${_dev} using key ${_key}."
-    echo "Plaintext device is at /dev/mapper/${_name}"
-    cryptsetup luksOpen ${_dev} ${_name} --key-file ${_key}
-
-  done < "${TAB}"
+  for entry in "$(grep -v -e '^#' -e '^ *$' ${TAB})"; do
+    dev="${entry%% *}"
+    key=$(echo ${entry} | tr -s ' ' | cut -d ' ' -f 2)
+    mount="${entry##* }"
+    mapper="${dev////_}"
+  
+    printf 'Decrypting %s using key %s.\n' "${dev}" "${key}"
+    cryptsetup luksOpen "${dev}" "${mapper}" --key-file "${key}"
+    printf 'Plaintext device is at /dev/mapper/%s\n' "${mapper}"
+
+    printf 'Mounting /dev/mapper/%s to %s\n' "${mapper}" "${mount}"
+    mount "/dev/mapper/${mapper}" "${mount}"
+  done
 }
 
 
-case $1 in
+case "${1:-}" in
 start)
   setup_entries
   mount -a