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tomb
executable file
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tomb
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#!/bin/zsh
#
# Tomb, the Crypto Undertaker
#
# A commandline tool to easily operate encryption of secret data
#
# Homepage on: [tomb.dyne.org](http://tomb.dyne.org)
# {{{ License
# Copyright (C) 2007-2013 Dyne.org Foundation
#
# Tomb is designed, written and maintained by Denis Roio <jaromil@dyne.org>
#
# With contributions by Anathema, Boyska and Hellekin O. Wolf.
#
# Testing and reviews are contributed by Dreamer, Shining,
# Mancausoft, Asbesto Molesto and Nignux.
#
# Tomb's artwork is contributed by Jordi aka Mon Mort.
#This source code is free software; you can redistribute it
#and/or modify it under the terms of the GNU Public License
#as published by the Free Software Foundation; either
#version 3 of the License, or (at your option) any later
#version.
#
#This source code is distributed in the hope that it will be
#useful, but WITHOUT ANY WARRANTY; without even the implied
#warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
#PURPOSE. Please refer to the GNU Public License for more
#details.
#
#You should have received a copy of the GNU Public License
#along with this source code; if not, write to: Free
#Software Foundation, Inc., 675 Mass Ave, Cambridge, MA
#02139, USA.
# }}} - License
# {{{ Global variables
VERSION=1.3
DATE="May/2013"
TOMBEXEC=$0
TOMBOPENEXEC="${TOMBEXEC}-open"
typeset -a OLDARGS
for arg in ${argv}; do OLDARGS+=($arg); done
DD="dd"
WIPE="rm -f"
MKFS="mkfs.ext3 -q -F -j -L"
STEGHIDE=1
MKTEMP=1
RESIZER=1
MOUNTOPTS="rw,noatime,nodev"
typeset -A global_opts
typeset -A opts
typeset -h username
typeset -h _uid
typeset -h _gid
typeset -h _tty
# Set a sensible PATH
PATH=/sbin:/bin:/usr/sbin:/usr/bin
[[ "$TOMBEXEC" =~ "^/usr/local" ]] && PATH="/usr/local/bin:/usr/local/sbin:$PATH"
# }}}
# {{{ Safety functions
_have_shm() {
# Check availability of 1MB of SHM
xxx "_have_shm 0 We need only 1 MB of RAM"
[[ -k /dev/shm ]] || return 1
local -i SHM RAM
SHM=$(df -k -B 4K -a -t tmpfs /dev/shm | awk '/\/dev\/shm/ { print $4; }')
(( $? )) && return 1
xxx "_have_shm 1 SHM $SHM KB are available"
RAM=$(awk '/MemFree/ { print $2 }' /proc/meminfo)
xxx "_have_shm 2 RAM $RAM KB are free"
(( $RAM >= 1024 )) && return 0
xxx "_have_shm 3 RAM $RAM KB left only :("
# Now we have more RAM than affected to SHM, so we can expect some for our little needs.
# Does that work when SHM is disabled from kernel config?
return 1
}
# Create temporary directories with caution
safe_dir() {
# Try and create our temporary directory in RAM
# Note that there's no warranty the underlying FS won't swap
# every 5 seconds (e.g., ext3)
local -i tries
while (( $tries < 3 )) ; do
tries+=1
if _have_shm; then
xxx "safe_dir creating directory in RAM"
if (( $MKTEMP )); then
mktemp -d /dev/shm/$1.$$.XXXXXXX
else
dir="/dev/shm/$1.$$.$RANDOM$RANDOM"
mkdir -m 0700 -p "$dir"
print "$dir"
fi
return 0
else
_warning "WARNING: we cannot ensure we're running in RAM."
xxx "Wait a bit before retrying... (attempt $tries)"
sync && sleep 0.5
fi
done
_warning "WARNING: no RAM available for me to run safely."
return 1
}
# Provide a random filename in shared memory
safe_filename() {
_have_shm || die "No access to shared memory on this system, sorry."
(( $MKTEMP )) && \
mktemp -u /dev/shm/$1.$$.XXXXXXX || \
print "/dev/shm/$1.$$.$RANDOM$RANDOM"
}
# Check if swap is activated
check_swap() {
# Return 0 if NO swap is used, 1 if swap is used
# Return 2 if swap(s) is(are) used, but ALL encrypted
local swaps=$(awk '/partition/ { print $1 }' /proc/swaps 2>/dev/null)
[[ -z "$swaps" ]] && return 0 # No swap partition is active
no "An active swap partition is detected, this poses security risks."
no "You can deactivate all swap partitions using the command:"
no " swapoff -a"
no "But if you want to proceed like this, use the -f (force) flag."
die "Operation aborted."
}
# Ask user for a password
ask_password() {
# we use pinentry now
# comes from gpg project and is much more secure
# it also conveniently uses the right toolkit
# pinentry has no custom icon setting
# so we need to temporary modify the gtk theme
if [ -r /usr/local/share/themes/tomb/gtk-2.0-key/gtkrc ]; then
GTK2_RC=/usr/local/share/themes/tomb/gtk-2.0-key/gtkrc
elif [ -r /usr/share/themes/tomb/gtk-2.0-key/gtkrc ]; then
GTK2_RC=/usr/share/themes/tomb/gtk-2.0-key/gtkrc
fi
title="Insert tomb password"
if [ $2 ]; then title="$2"; fi
output=`cat <<EOF | GTK2_RC_FILES=${GTK2_RC} pinentry 2>/dev/null | tail -n +7
OPTION ttyname=$TTY
OPTION lc-ctype=$LANG
SETTITLE $title
SETDESC $1
SETPROMPT Password:
GETPIN
EOF`
if [[ `tail -n1 <<<$output` =~ ERR ]]; then
return 1
fi
head -n1 <<<$output | awk '/^D / { sub(/^D /, ""); print }'
return 0
}
# Drop privileges
exec_as_user() {
if ! [ $SUDO_USER ]; then
exec $@[@]
return $?
fi
xxx "exec_as_user '$SUDO_USER': ${(f)@}"
sudo -u $SUDO_USER "${@[@]}"
return $?
}
#Escalate privileges
check_priv() {
# save original user
username=$USER
if [ $UID != 0 ]; then
xxx "Using sudo for root execution of 'tomb ${(f)OLDARGS}'"
# check if sudo has a timestamp active
sudok=false
if ! option_is_set --sudo-pwd; then
if [ $? != 0 ]; then # if not then ask a password
cat <<EOF | pinentry 2>/dev/null | awk '/^D / { sub(/^D /, ""); print }' | sudo -S -v
OPTION ttyname=$TTY
OPTION lc-ctype=$LANG
SETTITLE Super user privileges required
SETDESC Sudo execution of Tomb ${OLDARGS[@]}
SETPROMPT Insert your USER password:
GETPIN
EOF
fi
else
_verbose "Escalating privileges using sudo-pwd"
sudo -S -v <<<`option_value --sudo-pwd`
fi
sudo "${TOMBEXEC}" -U ${UID} -G ${GID} -T ${TTY} "${(@)OLDARGS}"
exit $?
fi # are we root already
# make sure necessary kernel modules are loaded
modprobe dm_mod
modprobe dm_crypt
return 0
}
# }}}
# {{{ Commandline interaction
usage() {
cat <<EOF
Syntax: tomb [options] command [file] [place]
Commands:
dig create a new empty TOMB file of --size in MB
forge create a new KEY file and set its password
lock installs a lock on a TOMB to use it with KEY
open open an existing TOMB
index update the search indexes of tombs
search looks for filenames matching text patterns
list list open TOMBs
close close a TOMB (or all)
slam slam a TOMB killing all programs using it
passwd change the password of a KEY
EOF
if [ "$RESIZER" = 1 ]; then
cat <<EOF
resize resize a TOMB to a new --size (can only grow)
EOF
fi
if [ "$STEGHIDE" = 1 ]; then
cat <<EOF
bury hide a KEY inside a JPEG image
exhume extract a KEY from a JPEG image
EOF
fi
cat <<EOF
Options:
-s size of the tomb file when creating/resizing one (in MB)
-k path to the key to be used ('-k -' to read from stdin)
-n don't process the hooks found in tomb
-o mount options used to open (default: rw,noatime,nodev)
-f force operation (i.e. even if swap is active)
-h print this help
-v print version, license and list of available ciphers
-q run quietly without printing informations
-D print debugging information at runtime
For more informations on Tomb read the manual: man tomb
Please report bugs on <http://github.com/dyne/tomb/issues>.
EOF
}
# Check an option
option_is_set() {
# First argument, the commandline flag (i.e. "-s").
# Second (optional) argument: if "out", command will print it out 'set'/'unset'
# (useful for if conditions).
# Return 0 if is set, 1 otherwise
[[ -n ${(k)opts[$1]} ]];
r=$?
if [[ $2 == out ]]; then
if [[ $r == 0 ]]; then
echo 'set'
else
echo 'unset'
fi
fi
return $r;
}
# Get an option value
option_value() {
# First argument, the commandline flag (i.e. "-s").
<<< ${opts[$1]}
}
# Messaging function with pretty coloring
function _msg() {
local command="print -P"
local progname="$fg[magenta]${TOMBEXEC##*/}$reset_color"
local message="$fg_bold[normal]$fg_no_bold[normal]${2}$reset_color"
local -i returncode
case "$1" in
inline)
command+=" -n"; pchars=" > "; pcolor="yellow"
;;
message)
pchars=" . "; pcolor="white"; message="$fg_no_bold[$pcolor]${2}$reset_color"
;;
verbose)
pchars="[D]"; pcolor="blue"
;;
success)
pchars="(*)"; pcolor="green"; message="$fg_no_bold[$pcolor]${2}$reset_color"
;;
warning)
pchars="[W]"; pcolor="yellow"; message="$fg_no_bold[$pcolor]${2}$reset_color"
;;
failure)
pchars="[E]"; pcolor="red"; message="$fg_no_bold[$pcolor]${2}$reset_color"
returncode=1
;;
*)
pchars="[F]"; pcolor="red"
message="Developer oops! Usage: _msg MESSAGE_TYPE \"MESSAGE_CONTENT\""
returncode=127
;;
esac
${=command} "${progname} $fg_bold[$pcolor]$pchars$reset_color ${message}$color[reset_color]" >&2
return $returncode
}
function _message say() {
local notice="message"
[[ "$1" = "-n" ]] && shift && notice="inline"
option_is_set -q || _msg "$notice" "$1"
return 0
}
alias act="_message -n"
function _verbose xxx() {
option_is_set -D && _msg verbose "$1"
return 0
}
function _success yes() {
option_is_set -q || _msg success "$1"
return 0
}
function _warning no() {
option_is_set -q || _msg warning "$1"
return 1
}
function _failure die() {
typeset -i exitcode=${2:-1}
option_is_set -q || _msg failure "$1"
exit $exitcode
}
# Print out progress to inform GUI caller applications (--batch mode)
progress() {
# $1 is "what is progressing"
# $2 is "percentage"
# $3 is (eventually blank) status
# Example: if creating a tomb, it could be sth like
# progress create 0 filling with random data
# progress create 40 generating key
# progress keygen 0 please move the mouse
# progress keygen 30 please move the mouse
# progress keygen 60 please move the mouse
# progress keygen 100 key generated
# progress create 80 please enter password
# progress create 90 formatting the tomb
# progress create 100 tomb created successfully
if ! option_is_set --batch; then
return
fi
print "[m][P][$1][$2][$3]" >&2
}
# Check what's installed
check_bin() {
# check for required programs
for req in cryptsetup pinentry sudo gpg; do
command -v $req >/dev/null || die "Cannot find $req. It's a requirement to use Tomb, please install it." 1
done
export PATH=/sbin:/usr/sbin:$PATH
# which dd command to use
command -v dcfldd > /dev/null
{ test $? = 0 } && { DD="dcfldd statusinterval=1" }
# which wipe command to use
command -v wipe > /dev/null && WIPE="wipe -f -s" || WIPE="rm -f"
# check for filesystem creation progs
command -v mkfs.ext4 > /dev/null && \
MKFS="mkfs.ext4 -q -F -j -L" || \
MKFS="mkfs.ext3 -q -F -j -L"
# check for mktemp
command -v mktemp > /dev/null || MKTEMP=0
# check for steghide
command -v steghide > /dev/null || STEGHIDE=0
# check for resize
command -v e2fsck resize2fs > /dev/null || RESIZER=0
if which tomb-kdf-pbkdf2 &> /dev/null; then
KDF_PBKDF2="tomb-kdf-pbkdf2"
else
local our_pbkdf2
our_pbkdf2="$(dirname $(readlink -f $TOMBEXEC))/kdf/tomb-kdf-pbkdf2"
if which $our_pbkdf2 &> /dev/null; then
KDF_PBKDF2=$our_pbkdf2
else
KDF_PBKDF2=
fi
fi
}
# }}} - Commandline interaction
# {{{ Key operations
typeset -h tombkeydir # global used if key comes from stdin
# This function retrieves a tomb key specified on commandline or one
# laying nearby the tomb if found, or from stdin if the option was
# selected. It also runs validity checks on the file. Callers should
# always use drop_key() when done with all key operations.
# On success returns 0 and prints out the full path to the key
load_key() {
# check if the key is set manually then use the one existing
local tombdir="$1"
local tombname="$2"
if option_is_set -k ; then
if [[ "`option_value -k`" == "-" ]]; then
# take key from stdin
tombkeydir=`safe_dir`
cat > ${tombkeydir}/stdin.tmp
tombkey=${tombkeydir}/stdin.tmp
else
# take key from a file
tombkey=`option_value -k`
fi
else
# guess key as lying besides the tomb
tombkey=${tombdir}/${tombname}.tomb.key
fi
if [ -r "${tombkey}" ]; then
_message "We'll use this key:"
_message " `ls -lh ${tombkey}`"
else
return 1
fi
# this does a check on the file header
if ! is_valid_key ${tombkey}; then
_warning "The key seems invalid, the application/pgp header is missing"
return 1
fi
print "$tombkey"
return 0
}
# This function asks the user for the password to use the key it tests
# it against the return code of gpg on success returns 0 and prints
# the password (be careful about where you save it!)
ask_key_password() {
tombkey="$1"
local keyname=`basename $tombkey`
_message "a password is required to use key ${keyname}"
local passok=0
local tombpass=""
if option_is_set --tomb-pwd; then
tombpass=`option_value --tomb-pwd`
else
for c in 1 2 3; do
if [ $c = 1 ]; then
tombpass=`exec_as_user ${TOMBEXEC} askpass "Insert password to use key: $keyname"`
else
tombpass=`exec_as_user ${TOMBEXEC} askpass "Insert password to use key: $keyname (retry $c)"`
fi
if [[ $? != 0 ]]; then
_warning "User aborted password dialog"
return 1
fi
get_lukskey "$tombpass" ${tombkey} >/dev/null
if [ $? = 0 ]; then
passok=1; _message "Password OK."
break;
fi
done
fi
{ test "$passok" = "1" } || { return 1 }
print "$tombpass"
unset $tombpass
return 0
}
# change tomb key password
change_passwd() {
_message "Commanded to change password for tomb key $1"
if ! option_is_set -f && ! option_is_set --ignore-swap; then check_swap; fi
local keyfile="$1" # $1 is the tomb key path
# check the keyfile
if ! [ -r $keyfile ]; then
_warning "key not found: $keyfile"
return 1
fi
if ! is_valid_key $keyfile ; then
_warning "file doesn't seems to be a tomb key: $keyfile"
_warning "operation aborted."
return 1
fi
local tmpnewkey lukskey c tombpass tombpasstmp
tmpnewkey=`safe_filename tombnew`
lukskey=`safe_filename tombluks`
_success "Changing password for $keyfile"
tombpass=`ask_key_password $keyfile`
{ test $? = 0 } || {
die "No valid password supplied" }
get_lukskey "${tombpass}" ${keyfile} > ${lukskey};
drop_key
{
gen_key $lukskey > ${tmpnewkey}
if ! is_valid_key $tmpnewkey; then
die "Error: the newly generated keyfile does not seem valid"
else
# copy the new key as the original keyfile name
cp "${tmpnewkey}" "${keyfile}"
_success "Your passphrase was successfully updated."
fi
} always {
_verbose "cleanup: $tmpnewkey $lukskey"
# wipe all temp file
${=WIPE} "${tmpnewkey}"
${=WIPE} "${lukskey}"
}
return $?
}
# To be called after load_key()
drop_key() {
{ test "$tombkeydir" = "" } && { return 0 }
{ test -r ${tombkeydir}/stdin.tmp } && {
${=WIPE} ${tombkeydir}/stdin.tmp; rmdir ${tombkeydir} }
}
#$1 is the keyfile we are checking
is_valid_key() {
# this header validity check is a virtuosism by Hellekin
[[ `file =(awk '/^-+BEGIN/,0' $1) -bi` =~ application/pgp ]]
return $?
}
# Gets a key file and a password, prints out the decoded contents to
# be used directly by Luks as a cryptographic key
get_lukskey() {
# $1 is the password, $2 is the keyfile
local tombpass=$1
local keyfile=$2
firstline=`head -n1 $keyfile`
xxx "get_lukskey XXX $keyfile"
if [[ $firstline =~ '^_KDF_' ]]; then
_verbose "KDF: `cut -d_ -f 3 <<<$firstline`"
case `cut -d_ -f 3 <<<$firstline` in
pbkdf2sha1)
if [[ -z $KDF_PBKDF2 ]]; then
die "The tomb use kdf method 'pbkdf2', which is unsupported on your system"
fi
pbkdf2_param=`cut -d_ -f 4- <<<$firstline | tr '_' ' '`
tombpass=$(${KDF_PBKDF2} ${=pbkdf2_param} 2> /dev/null <<<$tombpass)
;;
*)
_failure "No suitable program for KDF `cut -f 3 <<<$firstline`"
unset tombpass
return 1
;;
esac
fi
res=`safe_filename tomb.open`
(( $? )) && { unset tombpass; die "error creating temp dir" }
print ${tombpass} | \
gpg --batch --passphrase-fd 0 --no-tty --no-options --status-fd 2 \
-d "${keyfile}" 2>$res
unset tombpass
grep 'DECRYPTION_OKAY' $res
ret=$?; rm -f $res
xxx "get_lukskey returns $ret"
return $ret
}
# takes care to encrypt a key
# honored options: --kdf --tomb-pwd
gen_key() {
# $1 the lukskey to encrypt
local lukskey=$1
# here user is prompted for key password
local tombpass=""
local tombpasstmp=""
if ! option_is_set --tomb-pwd; then
while true; do
# 3 tries to write two times a matching password
tombpass=`exec_as_user ${TOMBEXEC} askpass "Secure key for ${tombname}"`
if [[ $? != 0 ]]; then
die "User aborted"
fi
if [ -z $tombpass ]; then
_warning "you set empty password, which is not possible"
continue
fi
tombpasstmp=$tombpass
tombpass=`exec_as_user ${TOMBEXEC} askpass "Secure key for ${tombname} (again)"`
if [[ $? != 0 ]]; then
die "User aborted"
fi
if [ "$tombpasstmp" = "$tombpass" ]; then
break;
fi
unset tombpasstmp
unset tombpass
done
else
tombpass=`option_value --tomb-pwd`
fi
# KDF is a new key strenghtening technique against brute forcing
# see: https://github.com/dyne/Tomb/issues/82
_verbose "KDF method chosen is: '`option_value --kdf`'"
kdf_method=$(cut -d: -f1 <<<`option_value --kdf` )
case $kdf_method in
pbkdf2)
if [[ -z $KDF_PBKDF2 ]]; then
die "The tomb use kdf method 'pbkdf2', which is unsupported on your system"
fi
# --kdf takes one parameter: iter time (on present machine) in seconds
seconds=$(cut -d: -f2 -s <<<`option_value --kdf`)
if [[ -z $seconds ]]; then
seconds=1
fi
local -i microseconds
microseconds=$((seconds*1000000))
_verbose "Microseconds: $microseconds"
pbkdf2_salt=`${KDF_PBKDF2}-gensalt`
pbkdf2_iter=`${KDF_PBKDF2}-getiter $microseconds`
# We use a length of 64bytes = 512bits (more than needed!?)
tombpass=`${KDF_PBKDF2} $pbkdf2_salt $pbkdf2_iter 64 <<<"${tombpass}"`
header="_KDF_pbkdf2sha1_${pbkdf2_salt}_${pbkdf2_iter}_64\n"
;;
""|null)
header=""
;;
*)
_warning "KDF method non recognized"
return 1
header=""
;;
esac
echo -n $header
print "${tombpass}" \
| gpg --openpgp --batch --no-options --no-tty --passphrase-fd 0 2>/dev/null \
-o - -c -a ${lukskey}
unset tombpass
}
# prints an array of ciphers available in gnupg (to encrypt keys)
list_gnupg_ciphers() {
# prints an error if GnuPG is not found
which gpg > /dev/null || die "gpg (GnuPG) is not found, Tomb cannot function without it."
ciphers=(`gpg --version | awk '
BEGIN { ciphers=0 }
/^Cipher:/ { gsub(/,/,""); sub(/^Cipher:/,""); print; ciphers=1; next }
/^Hash:/ { ciphers=0 }
{ if(ciphers==0) { next } else { gsub(/,/,""); print; } }
'`)
echo " ${ciphers}"
return 1
}
# Steganographic function to bury a key inside an image.
bury_key() {
tombkey=$1
imagefile=$2
file $tombkey | grep PGP > /dev/null
if [ $? != 0 ]; then
_warning "encode failed: $tombkey is not a tomb key"
return 1
fi
file $imagefile | grep JPEG > /dev/null
if [ $? != 0 ]; then
_warning "encode failed: $imagefile is not a jpeg image"
return 1
fi
_success "Encoding key $tombkey inside image $imagefile"
_message "please choose a password for the encoding"
# here user is prompted for key password
for c in 1 2 3; do
# 3 tries to write two times a matching password
tombpass=`exec_as_user ${TOMBEXEC} askpass "Steg password for ${tombkey}"`
tombpasstmp=$tombpass
tombpass=`exec_as_user ${TOMBEXEC} askpass "Steg password for ${tombkey} (again)"`
if [ "$tombpasstmp" = "$tombpass" ]; then
break;
fi
unset tombpasstmp
unset tombpass
done
if [ -z $tombpass ]; then
_warning "passwords don't match, aborting operation."
return 1
fi
# Requires steghide to be installed
awk '
/^-----/ {next}
/^Version/ {next}
{print $0}' ${tombkey} \
| steghide embed --embedfile - --coverfile ${imagefile} \
-p ${tombpass} -z 9 -e serpent cbc
if [ $? != 0 ]; then
_warning "encoding error: steghide reports problems"
res=1
else
_success "tomb key encoded succesfully into image ${imagefile}"
res=0
fi
unset tombpass
return $res
}
# Steganographic function to exhume a key buries into an image
exhume_key() {
tombname=$1
imagefile=$2
res=1
file $imagefile | grep JPEG > /dev/null
if [ $? != 0 ]; then
_warning "encode failed: $imagefile is not a jpeg image"
return 1
fi
keyfile=${tombname%%\.*}.tomb.key
if [[ -e "$keyfile" ]]; then
_warning "Key file $keyfile already exist."
return 1
fi
_message "Trying to exhume a key out of image $imagefile"
for c in 1 2 3; do
if [ $c = 1 ]; then
tombpass=`exec_as_user ${TOMBEXEC} askpass "Steg password for ${keyfile}"`
else
tombpass=`exec_as_user ${TOMBEXEC} askpass "Steg password for $keyfile (retry $c)"`
fi
# always steghide required
steghide extract -sf ${imagefile} -p ${tombpass} -xf - \
| awk '
BEGIN {
print "-----BEGIN PGP MESSAGE-----"
}
{ print $0 }
END {
print "-----END PGP MESSAGE-----"
}' > ${keyfile}
if [ "`cat ${keyfile} | wc -l`" != "3" ]; then
_success "${keyfile} succesfully decoded"
res=0
break;
fi
done
unset tombpass
if [ $res != 0 ]; then
_warning "nothing found."
fi
return $res
}
# }}} - Key handling
# {{{ Create
# This is a new way to create tombs which dissects the whole create_tomb() into 3 clear steps:
#
# * dig a .tomb (the large file) using /dev/random (takes some minutes at least)
#
# * forge a .key (the small file) using /dev/urandom (good entropy needed)
#
# * lock the .tomb file with the key, binding the key to the tomb (requires dm_crypt format)
forge_key() {
_message "Commanded to forge key $1"
if ! [ $1 ]; then
_warning "no key name specified for creation"
return 1
fi
# if swap is on, we remind the user about possible data leaks to disk
if ! option_is_set -f && ! option_is_set --ignore-swap; then check_swap; fi
# create the keyfile in tmpfs so that we leave less traces in RAM
keytmp=`safe_dir tomb`
(( $? )) && die "error creating temp dir"
xxx "safe_dir at $keytmp"
mount tmpfs "${keytmp}" -t tmpfs -o size=1m
if [ $? != 0 ]; then
_warning "cannot mount tmpfs filesystem in volatile memory"
rm -r "${keytmp}"
die "operation aborted."
fi
tombkey="$1"
_message "this operation takes time, keep using this computer on other tasks,"
_message "once done you will be asked to choose a password for your tomb."
_message "To make it faster you can move the mouse around."
_message "If you are on a server, you can use an Entropy Generation Daemon."
touch ${keytmp}/tomb.tmp
chmod 0600 ${keytmp}/tomb.tmp
random_source=/dev/random
if option_is_set --use-urandom; then
random_source=/dev/urandom
fi
xxx "Data dump using ${DD[1]} from $random_source"
${=DD} bs=1 count=256 if=$random_source of=${keytmp}/tomb.tmp
if ! [ -r ${keytmp}/tomb.tmp ]; then
_warning "cannot generate encryption key"
umount ${keytmp}
rm -r $keytmp
die "operation aborted."
fi
_success "Choose the password of your key: ${tombkey}"
_message "(you can also change it later using 'tomb passwd')"
touch ${tombkey}
chown ${_uid}:${_gid} ${tombkey}
chmod 0600 ${tombkey}
tombname="$tombkey"
# the gen_key() function takes care of the new key's encryption
gen_key ${keytmp}/tomb.tmp > ${tombkey}
# this does a check on the file header
if ! is_valid_key ${tombkey}; then
_warning "The key does not seem to be valid"
_warning "Dumping contents to screen:"
cat ${tombkey}
_warning "--"
umount ${keytmp}
rm -r $keytmp
die "operation aborted."
fi
${=WIPE} ${keytmp}/tomb.tmp # no need really, but anyway
umount ${keytmp}
rm -r ${keytmp}
chown ${_uid}:${_gid} ${tombkey}
_message "done forging $tombkey"
_success "Your key is ready:"
ls -lh ${tombkey}
}
# Dig a tomb, means that it will create an empty file to be formatted
# as a loopback filesystem. Initially the file is filled with random data
# taken from /dev/urandom which improves the tomb's overall security
dig_tomb() {
_message "Commanded to dig tomb $1"
# if swap is on, we remind the user about possible data leaks to disk
if ! option_is_set -f && ! option_is_set --ignore-swap; then check_swap; fi
if ! [ $1 ]; then
_warning "no tomb name specified for creation"
return 1
fi
tombfile=`basename $1`
tombdir=`dirname $1`
# make sure the file has a .tomb extension
tombname=${tombfile%%\.*}
tombfile=${tombname}.tomb
# require the specification of the size of the tomb (-s) in MB
tombsize="`option_value -s`"
[ $tombsize ] || die "Size argument missing, use --size"
[[ $tombsize != <-> ]] && die "Size argument is not an integer"
[[ $tombsize -lt 10 ]] && die "Tombs can't be smaller than 10 megabytes"
if [ -e ${tombdir}/${tombfile} ]; then
_warning "A tomb exists already. I'm not digging here:"
_warning " `ls -lh ${tombdir}/${tombfile}`"
return 1
fi
_success "Creating a new tomb in ${tombdir}/${tombfile}"
_message "Generating ${tombfile} of ${tombsize}MiB"
# we will first touch the file and set permissions: this way, even if interrupted, permissions are right
touch ${tombdir}/${tombfile}
chmod 0600 "${tombdir}/${tombfile}"
chown $_uid:$_gid "${tombdir}/${tombfile}"
xxx "Data dump using ${DD[1]} from /dev/urandom"
${=DD} if=/dev/urandom bs=1048576 count=${tombsize} of=${tombdir}/${tombfile}
if [ $? = 0 -a -e ${tombdir}/${tombfile} ]; then
_message " `ls -lh ${tombdir}/${tombfile}`"
else
die "Error creating the tomb ${tombdir}/${tombfile}, operation aborted."
fi
_success "Done digging $tombname"
_message "your tomb is not yet ready, you need to forge a key and lock it:"
_message "tomb forge ${tombname}.tomb.key"
_message "tomb lock ${tombname}.tomb ${tombname}.tomb.key"
}
# this function locks a tomb with a key file
# in fact LUKS formatting the loopback volume
# it take arguments as the LUKS cipher to be used
lock_tomb_with_key() {
if ! [ $1 ]; then
_warning "no tomb specified for locking"
_warning "usage: tomb lock file.tomb file.tomb.key"
return 1
fi
tombfile=`basename $1`
_message "Commanded to lock tomb ${tombfile}"
tombdir=`dirname $1`
# make sure the file has a .tomb extension
tombname=${tombfile%%\.*}
tombfile=${tombname}.tomb
{ test -f ${tombdir}/${tombfile} } || {