tomb

the crypto undertaker
git clone git://parazyd.org/tomb.git
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commit 75f50e7b0338983633abb789e902420d65885344
parent bc85112344518517969bf7c0890564247533b9ec
Author: Jaromil <jaromil@dyne.org>
Date:   Sun, 29 Aug 2010 14:56:53 +0200

fixed tomb creation
cleanup of unused functions
and more usability and fixes

Diffstat:
Msrc/tomb | 199+++++++++++++++++++------------------------------------------------------------
1 file changed, 48 insertions(+), 151 deletions(-)

diff --git a/src/tomb b/src/tomb @@ -30,6 +30,8 @@ VERSION=0.8 DATE=Aug/2010 +PATH=/usr/bin:/usr/sbin:/bin:/sbin + # standard output message routines # it's always useful to wrap them, in case we change behaviour later notice() { echo "[*] $1"; } @@ -37,6 +39,14 @@ act() { echo " . $1"; } error() { echo "[!] $1"; } func() { if [ $DEBUG ]; then echo "[D] $1"; fi } +# which dd command to use +which dcfldd > /dev/null +if [ $? = 0 ]; then + DD="dcfldd" +else + DD=dd +fi + # user interface (just to ask the password) ask_password() { @@ -63,76 +73,7 @@ ask_password() { } -# checks if a file is writable -# differs from -w coz returns true if does not exist but can be created -is_writable() { # arg: filename - - file=$1 - writable=false - - if [ -r $file ]; then # file exists - - if [ -w $file ]; then writable=true; fi - - else # file does not exist - - touch $file 1>/dev/null 2>/dev/null - if [ $? = 0 ]; then - writable=true - rm $file - fi - - fi - - if [ x$writable = xtrue ]; then - echo "true" - else - echo "false" - fi -} - -# appends a new line to a text file, if not duplicate -# it sorts alphabetically the original order of line entries -# defines the APPEND_FILE_CHANGED variable if file changes -append_line() { # args: file new-line - - # first check if the file is writable - # this also creates the file if doesn't exists - if [ `is_writable $1` = false ]; then - error "file $1 is not writable" - error "can't insert line: $2" - return - fi - - tempfile="`basename $1`.append.tmp" - - # create a temporary file and add the line there - cp $1 /tmp/$tempfile - echo "$2" >> /tmp/$tempfile - - # sort and uniq the temp file to temp.2 - cat /tmp/$tempfile | sort | uniq > /tmp/${tempfile}.2 - - SIZE1="`ls -l /tmp/$tempfile | awk '{print $5}'`" - SIZE2="`ls -l /tmp/${tempfile}.2 | awk '{print $5}'`" - if [ $SIZE != $SIZE ]; then - # delete the original - rm -f $1 - # replace it - cp -f /tmp/${tempfile}.2 $1 - # signal the change - APPEND_FILE_CHANGED=true - fi - - # remove the temporary files - rm -f /tmp/$tempfile - rm -f /tmp/${tempfile}.2 - - # and we are done -} - -PATH=/usr/bin:/usr/sbin:/bin:/sbin ############################ ### main() @@ -144,12 +85,18 @@ act "" func "invoked with args \"$*\" " func "running on `date`" +id | grep root > /dev/null +if [ $? != 0 ]; then + error "This program must be run as root to produce results" + exit 1 +fi + OPTS=`getopt -o hvs:k: -n 'tomb' -- "$@"` while true; do case "$1" in -h) - notice "Syntax: tomb [options] command [file] [mountpoint]" + notice "Syntax: tomb [options] command [file] [mountpoint | size]" act "" notice "Options:" act "-h print this help" @@ -158,7 +105,6 @@ while true; do act "-k path key to be used for decryption (defaults in ~/.tomb)" act "" notice "Commands:" - act "format format a PARTITION with NAME and generate keys" act "create create a new encrypted storage FILE and keys" act "mount mount an existing storage FILE on MOUNTPOINT" act "umount unmounts a mounted storage MOUNTPOINT" @@ -196,80 +142,27 @@ if ! [ -r ${tombtab} ]; then echo "# format here is similar to the system wide fstab" >> ${tombtab} echo "# <file system> <mount point> <type> <options> <key>" >> ${tombtab} fi - -format_tomb() { - notice "Formatting partition $FILE as an encrypted storage" - act "give it a name:" - read -s fsname - - act " `fdisk -l | grep ${FILE}`" - mkdir -p /tmp/tomb - - modprobe dm-crypt - modprobe aes-i586 - - act "Generating secret key..." - key="`basename ${FILE}`" - mkdir -p ${HOME}/.tomb - - cat /dev/urandom | strings | dd bs=1 count=256 of=/tmp/tomb/secret - notice "Setup your secret key file ${key}.gpg" - # here user is prompted for password - gpg -o "${HOME}/.tomb/${key}.gpg" --no-options --openpgp -c -a /tmp/tomb/secret - while [ $? = 2 ]; do - gpg -o "${HOME}/.tomb/${key}.gpg" --no-options --openpgp -c -a /tmp/tomb/secret - done - - act "formatting Luks partition" - # dm-crypt only supports sha1 - # but we can use aes-cbc-essiv with sha256 for better security - # see http://clemens.endorphin.org/LinuxHDEncSettings - cryptsetup --cipher aes-cbc-essiv:sha256 --key-size 256 luksFormat ${FILE} /tmp/tomb/secret - if ! [ $? = 0 ]; then - act "operation aborted." - exit 0 - fi - - - cryptsetup --key-file /tmp/tomb/secret --batch-mode --cipher aes luksOpen ${FILE} tomb.tmp - - rm -f /tmp/tomb/secret - - cryptsetup luksDump ${FILE} - - mkfs.ext3 -F -L "${fsname}" -j /dev/mapper/tomb.tmp - - if [ $? = 0 ]; then - act "OK, encrypted partition succesfully formatted with Ext3 filesystem" - else - act "error formatting ${FILE} Ext3 filesystem" - fi - - cryptsetup luksClose tomb.tmp - - notice "done formatting $FILE encrypted partition (using Luks dm-crypt AES/SHA256)" - act "encrypted key stored in file ${tombdir}/${key}.gpg" - append_line ${tombtab} \ - "${FILE} ${tombdir}/`basename ${FILE}` aes-cbc-essiv:sha256 none ${tombdir}/${key}.gpg" -} create_tomb() { + notice "Creating a new tomb in ${FILE}" if [ -z $SIZE ]; then - error "size is not specified, please use -s option when creating a storage file" - exit 0 - else - act "size set to $SIZE MB" + if [ $MOUNT ]; then + SIZE=$MOUNT + else + error "size is not specified, please use -s option when creating a tomb" + exit 0 + fi fi SIZE_4k=`expr \( $SIZE \* 1000 \) / 4` - notice "generating file of ${SIZE}Mb (${SIZE_4k} blocks of 4Kb)" - act "dd if=/dev/zero of=${FILE} bs=4k count=$SIZE_4k" -# now with progress bar! - dd if=/dev/zero bs=4k count=${SIZE_4k} of=${FILE} + act "Generating file of ${SIZE}Mb (${SIZE_4k} blocks of 4Kb)" +# TODO: use dd_rescue and/or dcfldd + $DD if=/dev/urandom bs=4k count=${SIZE_4k} of=${FILE} +# dd if=/dev/urandom bs=4k count=${SIZE_4k} of=${FILE} if [ $? = 0 -a -e ${FILE} ]; then - act "OK: `ls -l ${FILE}`" + act "OK: `ls -lh ${FILE}`" else error "Error creating the nest file ${FILE} : (dd if=/dev/zero of=${FILE} bs=4k count=$SIZE_4k)" sleep 4 @@ -283,23 +176,26 @@ create_tomb() { nstloop=`losetup -f` # get the number for next loopback device losetup -f ${FILE} # allocates the next loopback for our file - + keytmp=`tempfile` act "Generating secret key..." - - cat /dev/urandom | strings | dd bs=1 count=256 of=/tmp/tomb/secret - clear + act "this operation takes time, computer use helps to gather more entropy." + cat /dev/random | dd bs=1 count=256 of=${keytmp} + notice "Setup your secret key file ${FILE}.gpg" - # here user is prompted for password - gpg -o "${FILE}.gpg" --no-options --openpgp -c -a /tmp/tomb/secret + # here user is prompted for key password + gpg -o "${FILE}.gpg" --no-options --openpgp -c -a ${keytmp} while [ $? = 2 ]; do - gpg -o "${FILE}.gpg" --no-options --openpgp -c -a /tmp/tomb/secret + gpg -o "${FILE}.gpg" --no-options --openpgp -c -a ${keytmp} done act "formatting Luks mapped device" # dm-crypt only supports sha1 # but we can use aes-cbc-essiv with sha256 for better security # see http://clemens.endorphin.org/LinuxHDEncSettings - cryptsetup --cipher aes-cbc-essiv:sha256 --key-size 256 luksFormat ${nstloop} /tmp/tomb/secret + cryptsetup --batch-mode \ + --cipher aes-cbc-essiv:sha256 --key-size 256 \ + luksFormat ${nstloop} ${keytmp} + if ! [ $? = 0 ]; then act "operation aborted." exit 0 @@ -307,13 +203,13 @@ create_tomb() { act "formatting Ext3 filesystem" - cryptsetup --key-file /tmp/tomb/secret --batch-mode --cipher aes luksOpen ${nstloop} tomb.tmp + cryptsetup --key-file ${keytmp} --cipher aes luksOpen ${nstloop} tomb.tmp - rm -f /tmp/tomb/secret + rm -f ${keytmp} - cryptsetup luksDump ${nstloop} +# cryptsetup luksDump ${nstloop} - mkfs.ext3 -F -j -L "dyne:nest" /dev/mapper/tomb.tmp + mkfs.ext3 -q -F -j -L "`hostname`-`date +%s`" /dev/mapper/tomb.tmp if [ $? = 0 ]; then act "OK, encrypted storage succesfully formatted with Ext3 filesystem" @@ -321,6 +217,8 @@ create_tomb() { act "error formatting storage file with Ext3 filesystem" fi + sync + cryptsetup luksClose tomb.tmp losetup -d ${nstloop} @@ -346,7 +244,7 @@ create_tomb() { mount_tomb() { if [ -z $KEY ]; then - enc_key="~/.tomb/`basename $FILE`" + enc_key="`basename ${FILE}.gpg`" else enc_key="$KEY" fi @@ -422,7 +320,6 @@ mount_tomb() { # -o rw,noatime,nodev notice "encrypted storage $FILE succesfully mounted on $MOUNT" - append_line /var/run/tombs "${MOUNT} ${mapper} ${nstloop}" else @@ -444,7 +341,7 @@ umount_tomb() { FILE=`mount | grep $mapper | awk '{print $3}'` else error "too many tombs mounted, please specify which to unmount:" - ls -l /dev/mapper/tomb* + ls /dev/mapper/tomb* echo return fi