mod-luks.sh

   1 #!/bin/sh
   2 LUKS_RCSID='$Revision$ $Date::                            $'
   3
   4 # geninitrd mod: cryptsetup luks
   5 USE_LUKS=${USE_LUKS:-yes}
   6
   7 # true if root device is crypted with cryptsetup luks
   8 # and we should init cryptsetup luks at boot
   9 have_luks=no
  10
  11 # device to use for name for cryptsetup luks
  12 LUKSNAME=""
  13
  14 # setup geninitrd module
  15 # @access       public
  16 setup_mod_luks() {
  17         cryptsetup=$(find_tool $initrd_dir/cryptsetup /sbin/cryptsetup-initrd)
  18
  19         if [ ! -x /sbin/cryptsetup ] || [ ! -x "$cryptsetup" ]; then
  20                 USE_LUKS=no
  21         fi
  22 }
  23
  24 # return true if node is cryptsetup luks encrypted
  25 # @param        string $node device node to be examined
  26 # @access       public
  27 is_luks() {
  28         local node="$1"
  29
  30         # luks not wanted
  31         if is_no "$USE_LUKS"; then
  32                 return 1
  33         fi
  34
  35         if [ ! -e "$node" ]; then
  36                 warn "is_luks(): node $node doesn't exist!"
  37                 return 1
  38         fi
  39
  40         local dev dm_status dm_name=${node#/dev/mapper/}
  41         if [ "$node" = "$dm_name" ]; then
  42                 debug "is_luks: $node is not device mapper name"
  43                 return 1
  44         fi
  45
  46         dev=$(/sbin/cryptsetup status $dm_name 2>/dev/null | awk '/device:/{print $2}')
  47         if [ "$dev" ]; then
  48                 /sbin/cryptsetup isLuks $dev
  49                 rc=$?
  50         else
  51                 # If luks partition was activated using old cryptsetup (at initrd level)
  52                 # then "device:" report could be missing from cryptsetup status above.
  53                 # Fallback to dmsetup report in such case.
  54                 dm_status=$(/sbin/dmsetup status --target crypt $dm_name 2>/dev/null)
  55                 if [ -n "$dm_status" ]; then
  56                         rc=0
  57                 else
  58                         rc=1
  59                 fi
  60         fi
  61
  62         if [ $rc = 0 ]; then
  63                 debug "is_luks: $node is cryptsetup luks"
  64         else
  65                 debug "is_luks: $node is not cryptsetup luks"
  66         fi
  67         return $rc
  68 }
  69
  70 # find modules for $devpath
  71 # @param        $devpath        device to be examined
  72 # @access       public
  73 find_modules_luks() {
  74         local devpath="$1"
  75         local dev=""
  76
  77         LUKSNAME=${devpath#/dev/mapper/}
  78
  79         find_module "dm-crypt"
  80
  81         # TODO: autodetect
  82         find_module "aes"
  83         find_module "cbc"
  84
  85         # recurse
  86         dev=$(awk '$1 == "'"$LUKSNAME"'" { print $2 }' /etc/crypttab)
  87         if [ -n "$dev" ] ; then
  88                 find_modules_for_devpath $dev
  89                 have_luks=yes
  90         else
  91                 die "Cannot find '$LUKSNAME' in /etc/crypttab"
  92         fi
  93 }
  94
  95
  96 # generate initrd fragment for cryptsetup luks init
  97 # @access       public
  98 initrd_gen_luks() {
  99         if ! is_yes "$have_luks"; then
 100                 return
 101         fi
 102
 103         inst_d /bin
 104         inst_exec $cryptsetup /bin/cryptsetup
 105
 106         mount_dev
 107         mount_sys
 108         initrd_gen_devices
 109         # TODO: 'udevadm settle' is called by lukssetup, is udev optional?
 110
 111         debug "luks: process /etc/crypttab $LUKSNAME"
 112         luks_crypttab $LUKSNAME
 113 }
 114
 115
 116 # PRIVATE METHODS
 117 key_is_random() {
 118         [ "$1" = "/dev/urandom" -o "$1" = "/dev/hw_random" -o "$1" = "/dev/random" ]
 119 }
 120
 121 # produce cryptsetup from $name from /etc/crypttab
 122 luks_crypttab() {
 123         local LUKSNAME="$1"
 124
 125         # copy from /etc/rc.d/init.d/cryptsetup
 126         local dst src key opt mode owner
 127
 128         while read dst src key opt; do
 129                 [ "$dst" != "$LUKSNAME" ] && continue
 130
 131                 if [ -n "$key" -a "x$key" != "xnone" ]; then
 132                         if test -e "$key" ; then
 133                                 mode=$(LC_ALL=C ls -l "$key" | cut -c 5-10)
 134                                 owner=$(LC_ALL=C ls -l $key | awk '{ print $3 }')
 135                                 if [ "$mode" != "------" ] && ! key_is_random "$key"; then
 136                                         die "INSECURE MODE FOR $key"
 137                                 fi
 138                                 if [ "$owner" != root ]; then
 139                                         die "INSECURE OWNER FOR $key"
 140                                 fi
 141                         else
 142                                 die "Key file for $dst not found"
 143                         fi
 144                 else
 145                         key=""
 146                 fi
 147
 148                 if /sbin/cryptsetup isLuks "$src" 2>/dev/null; then
 149                         if key_is_random "$key"; then
 150                                 die "$dst: LUKS requires non-random key, skipping"
 151                         fi
 152                         if [ -n "$opt" ]; then
 153                                 warn "$dst: options are invalid for LUKS partitions, ignoring them"
 154                         fi
 155                         if [ "$key" ]; then
 156                                 keyfile=/etc/.$dst.key
 157                                 inst $key $keyfile
 158                         fi
 159
 160                         debug "+ cryptsetup ${keyfile:+-d $keyfile} luksOpen '$src' '$dst'"
 161                         add_linuxrc <<-EOF
 162                         # cryptsetup can be called twice and in case on crypt on lvm only second
 163                         # will succeed because there will be no src device in first cryptsetup call
 164                         # this can be called multiple times, before lvm and after lvm.
 165                         luksdev='$src'
 166                         if [ \${luksdev##/dev/disk/by-uuid/} != \${luksdev} ]; then
 167                                 src_uuid=\${luksdev##/dev/disk/by-uuid/}
 168                                 while read x y z name; do
 169                                         found_uuid=\$(cryptsetup luksUUID /dev/\${name} 2>/dev/null)
 170                                         if [ "\$found_uuid" = "\$src_uuid" ]; then
 171                                                 luksdev=/dev/\$name
 172                                                 break
 173                                         fi
 174                                 done < /proc/partitions
 175                         fi
 176
 177                         if [ -e "\$luksdev" ]; then
 178                                 crypt_status=\$(cryptsetup status '$dst')
 179                                 if [ "\${crypt_status%%is inactive.}" != "\$crypt_status" ]; then
 180                                         # is inactive
 181                                         cryptsetup ${keyfile:+-d $keyfile} luksOpen "\$luksdev" '$dst' <&1
 182                                 fi
 183                         fi
 184
 185                         debugshell
 186                         EOF
 187                 else
 188                         die "$dst: only LUKS encryption supported"
 189                 fi
 190         done < /etc/crypttab
 191 }