cryptsetup/trunk/hooks-encrypt

   1 #!/usr/bin/ash
   2
   3 run_hook() {
   4     modprobe -a -q dm-crypt >/dev/null 2>&1
   5     [ "${quiet}" = "y" ] && CSQUIET=">/dev/null"
   6
   7     # Get keyfile if specified
   8     ckeyfile="/crypto_keyfile.bin"
   9     if [ -n "$cryptkey" ]; then
  10         IFS=: read ckdev ckarg1 ckarg2 <<EOF
  11 $cryptkey
  12 EOF
  13
  14         if [ "$ckdev" = "rootfs" ]; then
  15             ckeyfile=$ckarg1
  16         elif resolved=$(resolve_device "${ckdev}" ${rootdelay}); then
  17             case ${ckarg1} in
  18                 *[!0-9]*)
  19                     # Use a file on the device
  20                     # ckarg1 is not numeric: ckarg1=filesystem, ckarg2=path
  21                     mkdir /ckey
  22                     mount -r -t "$ckarg1" "$resolved" /ckey
  23                     dd if="/ckey/$ckarg2" of="$ckeyfile" >/dev/null 2>&1
  24                     umount /ckey
  25                     ;;
  26                 *)
  27                     # Read raw data from the block device
  28                     # ckarg1 is numeric: ckarg1=offset, ckarg2=length
  29                     dd if="$resolved" of="$ckeyfile" bs=1 skip="$ckarg1" count="$ckarg2" >/dev/null 2>&1
  30                     ;;
  31             esac
  32         fi
  33         [ ! -f ${ckeyfile} ] && echo "Keyfile could not be opened. Reverting to passphrase."
  34     fi
  35
  36     if [ -n "${cryptdevice}" ]; then
  37         DEPRECATED_CRYPT=0
  38         IFS=: read cryptdev cryptname cryptoptions <<EOF
  39 $cryptdevice
  40 EOF
  41     else
  42         DEPRECATED_CRYPT=1
  43         cryptdev="${root}"
  44         cryptname="root"
  45     fi
  46
  47     # This may happen if third party hooks do the crypt setup
  48     if [ -b "/dev/mapper/${cryptname}" ]; then
  49         echo "Device ${cryptname} already exists, not doing any crypt setup."
  50         return 0
  51     fi
  52
  53     warn_deprecated() {
  54         echo "The syntax 'root=${root}' where '${root}' is an encrypted volume is deprecated"
  55         echo "Use 'cryptdevice=${root}:root root=/dev/mapper/root' instead."
  56     }
  57
  58     set -f
  59     OLDIFS="$IFS"; IFS=,
  60     for cryptopt in ${cryptoptions}; do
  61         case ${cryptopt} in
  62             allow-discards|discard)
  63                 cryptargs="${cryptargs} --allow-discards"
  64                 ;;
  65             no-read-workqueue|perf-no_read_workqueue)
  66                 cryptargs="${cryptargs} --perf-no_read_workqueue"
  67                 ;;
  68             no-write-workqueue|perf-no_write_workqueue)
  69                 cryptargs="${cryptargs} --perf-no_write_workqueue"
  70                 ;;
  71             *)
  72                 echo "Encryption option '${cryptopt}' not known, ignoring." >&2
  73                 ;;
  74         esac
  75     done
  76     set +f
  77     IFS="$OLDIFS"
  78     unset OLDIFS
  79
  80     if resolved=$(resolve_device "${cryptdev}" ${rootdelay}); then
  81         if cryptsetup isLuks ${resolved} >/dev/null 2>&1; then
  82             [ ${DEPRECATED_CRYPT} -eq 1 ] && warn_deprecated
  83             dopassphrase=1
  84             # If keyfile exists, try to use that
  85             if [ -f ${ckeyfile} ]; then
  86                 if eval cryptsetup --key-file ${ckeyfile} open --type luks ${resolved} ${cryptname} ${cryptargs} ${CSQUIET}; then
  87                     dopassphrase=0
  88                 else
  89                     echo "Invalid keyfile. Reverting to passphrase."
  90                 fi
  91             fi
  92             # Ask for a passphrase
  93             if [ ${dopassphrase} -gt 0 ]; then
  94                 echo ""
  95                 echo "A password is required to access the ${cryptname} volume:"
  96
  97                 #loop until we get a real password
  98                 while ! eval cryptsetup open --type luks ${resolved} ${cryptname} ${cryptargs} ${CSQUIET}; do
  99                     sleep 2;
 100                 done
 101             fi
 102             if [ -e "/dev/mapper/${cryptname}" ]; then
 103                 if [ ${DEPRECATED_CRYPT} -eq 1 ]; then
 104                     export root="/dev/mapper/root"
 105                 fi
 106             else
 107                 err "Password succeeded, but ${cryptname} creation failed, aborting..."
 108                 return 1
 109             fi
 110         elif [ -n "${crypto}" ]; then
 111             [ ${DEPRECATED_CRYPT} -eq 1 ] && warn_deprecated
 112             msg "Non-LUKS encrypted device found..."
 113             if echo "$crypto" | awk -F: '{ exit(NF == 5) }'; then
 114                 err "Verify parameter format: crypto=hash:cipher:keysize:offset:skip"
 115                 err "Non-LUKS decryption not attempted..."
 116                 return 1
 117             fi
 118             exe="cryptsetup open --type plain $resolved $cryptname $cryptargs"
 119             IFS=: read c_hash c_cipher c_keysize c_offset c_skip <<EOF
 120 $crypto
 121 EOF
 122             [ -n "$c_hash" ]    && exe="$exe --hash '$c_hash'"
 123             [ -n "$c_cipher" ]  && exe="$exe --cipher '$c_cipher'"
 124             [ -n "$c_keysize" ] && exe="$exe --key-size '$c_keysize'"
 125             [ -n "$c_offset" ]  && exe="$exe --offset '$c_offset'"
 126             [ -n "$c_skip" ]    && exe="$exe --skip '$c_skip'"
 127             if [ -f "$ckeyfile" ]; then
 128                 exe="$exe --key-file $ckeyfile"
 129             else
 130                 echo ""
 131                 echo "A password is required to access the ${cryptname} volume:"
 132             fi
 133             eval "$exe $CSQUIET"
 134
 135             if [ $? -ne 0 ]; then
 136                 err "Non-LUKS device decryption failed. verify format: "
 137                 err "      crypto=hash:cipher:keysize:offset:skip"
 138                 return 1
 139             fi
 140             if [ -e "/dev/mapper/${cryptname}" ]; then
 141                 if [ ${DEPRECATED_CRYPT} -eq 1 ]; then
 142                     export root="/dev/mapper/root"
 143                 fi
 144             else
 145                 err "Password succeeded, but ${cryptname} creation failed, aborting..."
 146                 return 1
 147             fi
 148         else
 149             err "Failed to open encryption mapping: The device ${cryptdev} is not a LUKS volume and the crypto= paramater was not specified."
 150         fi
 151     fi
 152     rm -f ${ckeyfile}
 153 }
 154
 155 # vim: set ft=sh ts=4 sw=4 et: