Tomb/tomb

#!/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=1.4
DATE="Jun/2013"
TOMBEXEC=$0
typeset -a OLDARGS
for arg in ${argv}; do OLDARGS+=($arg); done
DD="dd"
WIPE="rm -f"
MKFS="mkfs.ext3 -q -F -j -L"
KDF=1
STEGHIDE=1
MKTEMP=1
RESIZER=1
SWISH=1
QRENCODE=1
MOUNTOPTS="rw,noatime,nodev"

typeset -A global_opts
typeset -A opts
typeset -h username

typeset -h tombkeydir # global used if key comes from stdin
tombkeydir=""

typeset -h _uid
typeset -h _gid
typeset -h _tty

# Set a sensible PATH
# PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/bin


# }}}

# {{{ 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 $1 dir in RAM"
	    if (( $MKTEMP )); then
		mktemp -d /dev/shm/tomb.$1.$$.XXXXXXX
	    else
		dir="/dev/shm/tomb.$1.$$.$RANDOM$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/tomb.$1.$$.XXXXXXX || \
	print "/dev/shm/tomb.$1.$$.$RANDOM$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 '/^\// { print $1 }' /proc/swaps 2>/dev/null)"
    [[ -z "$swaps" ]] && return 0                # No swap partition is active
    # Check whether all swaps are encrypted, and return 2
    # If any of the swaps is not encrypted, we bail out and return 1.
    ret=1
    for s in $=swaps; do
	bone=`sudo file $s`
	if `echo "$bone" | grep 'swap file' &>/dev/null`; then
	    # It's a regular (unencrypted) swap file
	    ret=1
	    break
        elif `echo "$bone" | grep 'symbolic link' &>/dev/null`; then
	    # Might link to a block
	    ret=1
	    if [ "/dev/mapper" = "${s%/*}" ]; then
		is_crypt=`sudo dmsetup status "$s" | awk '/crypt/ {print $3}'`
		if [ "crypt" = "$is_crypt" ]; then
		    ret=2
		fi
	    else
		break
	    fi
	elif `echo "$bone" | grep 'block special' &>/dev/null`; then
	    # Is a block
	    ret=1
            is_crypt=`sudo dmsetup status "$s" | awk '/crypt/ {print $3}'`
	    if [ "crypt" = "$is_crypt" ]; then
		ret=2
	    else
		break
	    fi
	fi
    done
    no  "An active swap partition is detected, this poses security risks."
    if [[ $ret -eq 2 ]]; then
	yes "All your swaps are belong to crypt.  Good."
    else
	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."
    fi
    return $ret
}

# Wrapper to allow encrypted swap and remind the user about
# possible data leaks to disk if swap is on, and not to be ignored
_check_swap() {
    if ! option_is_set -f && ! option_is_set --ignore-swap; then
	check_swap
	case $? in
	    0|2)     # No, or encrypted swap
		return 0
		;;
	    *)       # Unencrypted swap
		return 1
		;;
	esac
    fi
}

# 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 [ $UID != 0 ]; then
	xxx "Using sudo for root execution of '${TOMBEXEC} ${(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

    # check if we have support for loop mounting
    losetup -f > /dev/null
    { test "$?" = "0" } || {
	no "Loop mount of volumes is not supported on this machine, this error"
	no "often occurs on VPS and kernels that don't provide the loop module."
	no "It is impossible to use Tomb on this machine at this conditions."
	die "Operation aborted."
    }

    # make sure necessary kernel modules are loaded
    modprobe dm_mod 2>/dev/null
    modprobe dm_crypt 2>/dev/null

    return 0
}

# check if a filename is a valid tomb
is_valid_tomb() {
    xxx "is_valid_tomb $1"
    # argument check
    { test "$1" = "" } && {
	_warning "Tomb file is missing from arguments"; return 1 }
    # file checks
    { test -r "$1" } || {
	_warning "Tomb file not found: $1"; return 1 }
    { test -f "$1" } || {
	_warning "Tomb file is not a regular file: $1"; return 1 }
    # check file type (if its a Luks fs)
    file "$1" | grep -i 'luks encrypted file' >/dev/null
    { test $? = 0 } || {
	_warning "File is not a valid tomb: $1"; return 1 }
    # check if its already open
    tombfile=`basename $1`
    tombname=${tombfile%%\.*}
    mount -l | grep "${tombfile}.*\[$tombname\]$" > /dev/null
    { test $? = 0 } && {
	_warning "Tomb is currently in use: $tombname"; return 1 }
    _message "Valid tomb file found: $1"
    return 0
}
# }}}

# {{{ Commandline interaction

usage() {
    cat <<EOF

Syntax: tomb [options] command [arguments]

Commands:

 // Creation:
 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

 // Operations on tombs:
 open    open an existing TOMB
 index   update the search indexes of tombs
 search  looks for filenames matching text patterns
 list    list of open TOMBs and information on them
 close   close a specific TOMB (or 'all')
 slam    slam a TOMB killing all programs using it
EOF
    if [ "$RESIZER" = 1 ]; then
	cat <<EOF
 resize  resize a TOMB to a new --size (can only grow)
EOF
    fi
cat <<EOF

 // Operations on keys:
 passwd  change the password of a KEY
 setkey  change the KEY locking a TOMB (needs old one)
EOF

    { test "$QRENCODE" = "1" } && {
	cat <<EOF
 engrave makes a QR code of a KEY to be saved on paper
EOF
    }

    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)
EOF
    { test "$KDF" = 1 } && {
	cat <<EOF
 --kdf  generate passwords armored against dictionary attacks
EOF
    }

cat <<EOF

 -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
    # check for KDF auxiliary tools
    command -v tomb-kdb-pbkdf2 > /dev/null || KDF=0
    # check for Swish-E file content indexer
    command -v swish-e > /dev/null || SWISH=0
    # check for QREncode for paper backups of keys
    command -v qrencode > /dev/null || QRENCODE=0
}

# }}} - Commandline interaction

# {{{ Key operations

# 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() {
    # take the name of a tomb file as argument
    # this is used for guessing if the key is nearby
    { test "$1" = "" } || {
	tombdir=`dirname $1`
	tombfile=`basename $1`
	tombname=${tombfile%%\.*}
    }

    if option_is_set -k ; then
	if [[ "`option_value -k`" == "-" ]]; then
	    xxx "load_key reading from stdin"
	    # take key from stdin
	    tombkeydir=`safe_dir load_key`
	    xxx "tempdir is $tombkeydir"
	    cat > ${tombkeydir}/stdin.tmp
	    tombdir=${tombkeydir}
	    tombfile=stdin.tmp
	    tombname="stdin"
	elif [[ "`option_value -k`" != "" ]]; then
	    # take key from a file
	    tombkey=`option_value -k`
	    tombdir=`dirname $tombkey`
	    tombfile=`basename $tombkey`
	fi
    fi

    tombkey=${tombdir}/${tombfile}

    xxx "load_key: `ls -lh ${tombkey}`"

    if [ -r "${tombkey}" ]; then
	_message "We'll use this key: ${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`
	    xxx "ask_key_password takes tombpass from CLI argument: $tombpass"

	    get_lukskey "$tombpass" ${tombkey} >/dev/null

	    if [ $? = 0 ]; then
		passok=1; _message "Password OK."; fi

    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"
    _check_swap

    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 passnew`
    lukskey=`safe_filename passold`

    _success "Changing password for $keyfile"

    tombpass=`ask_key_password $keyfile`
    { test $? = 0 } || {
	die "No valid password supplied" }

    get_lukskey "${tombpass}" ${keyfile} > ${lukskey};

    drop_key

    {

	local algo
	{ option_is_set -o } && { algopt="`option_value -o`" }

	gen_key $lukskey $algopt > ${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() {
    xxx "is_valid_key $1"
    # argument check
    { test "$1" = "" } && {
	_warning "Key file is missing from arguments"; return 1 }
    # file checks
    { test -r "$1" } || {
	_warning "Key file not found: $1"; return 1 }
    { test -f "$1" } || {
	_warning "Key file is not a regular file: $1"; return 1 }
    # this header validity check is a virtuosism by Hellekin
    [[ `file =(awk '/^-+BEGIN/,0' $1)` =~ PGP ]] && {
	_message "Valid key file found: $1"; return 0 }
    # if no BEGIN header found then we try to recover it
    [[ `file $1 -bi` =~ text/plain ]] && {
	_warning "Key data found with missing headers, attempting recovery"
	local tmp_keyfix=`safe_filename keyfix`
	touch $tmp_keyfix
	# make sure KDF header comes first
	local header=`grep '^_KDF_' $1`
	print "$header" >> $tmp_keyfix
	cat $1 | awk '
BEGIN {
print "-----BEGIN PGP MESSAGE-----"
print
}
/^_KDF_/ { next }
{ print $0 }
END {
print "-----END PGP MESSAGE-----"
}' >> ${tmp_keyfix}
	mv $tmp_keyfix $1
	chown ${_uid}:${_gid} ${1}
	chmod 0600 ${1}
	return 0
    }
    _warning "Invalid key format: $1"
    return 1
}


# 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 <<<$firstline` in
	    pbkdf2sha1)
		pbkdf2_param=`cut -d_ -f 4- <<<$firstline | tr '_' ' '`
		tombpass=$(tomb-kdb-pbkdf2 ${=pbkdf2_param} 2> /dev/null <<<$tombpass)
		;;
	    *)
		_failure "No suitable program for KDF `cut -f 3 <<<$firstline`"
		unset tombpass
		return 1
		;;
	esac
    fi

    # fix for gpg 1.4.11 where the --status-* options don't work ;^/
    gpgver=`gpg --version | awk '/^gpg/ {print $3}'`
    if [ "$gpgver" = "1.4.11" ]; then
	xxx "GnuPG is version 1.4.11 - adopting status fix"

	print ${tombpass} | \
	    gpg --batch --passphrase-fd 0 --no-tty --no-options -d "${keyfile}"
	ret=$?
	unset tombpass

    else # using status-file in gpg != 1.4.11

	res=`safe_filename lukskey`
	{ test $? = 0 } || { unset tombpass; die "Fatal error creating temp file." }

	print ${tombpass} | \
	    gpg --batch --passphrase-fd 0 --no-tty --no-options --status-fd 2 \
	    --no-mdc-warning --no-permission-warning --no-secmem-warning \
	    -d "${keyfile}" 2> $res

	unset tombpass
	grep 'DECRYPTION_OKAY' $res > /dev/null
	ret=$?; rm -f $res

    fi
    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
# $2 is the --cipher-algo to use (string taken by GnuPG)
    local lukskey="$1"
    local algo="${2:-AES256}"
    # 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`"
	xxx "gen_key takes tombpass from CLI argument: $tombpass"
    fi

    header=""
    { test "$KDF" = 1 } && {
	{ option_is_set --kdf } && {
    # KDF is a new key strenghtening technique against brute forcing
    # see: https://github.com/dyne/Tomb/issues/82
	    itertime="`option_value --kdf`"
	# removing support of floating points because they can't be type checked well
	    if [[ "$itertime" != <-> ]]; then
		unset tombpass
		unset tombpasstmp
		die "Wrong argument for --kdf: must be an integer number (iteration seconds)"
	    fi
	    # --kdf takes one parameter: iter time (on present machine) in seconds
	    local -i microseconds
	    microseconds=$((itertime*10000))
	    yes "Using KDF, iterations: $microseconds"
	    pbkdf2_salt=`tomb-kdb-pbkdf2-gensalt`
	    pbkdf2_iter=`tomb-kdb-pbkdf2-getiter $microseconds`
	    # We use a length of 64bytes = 512bits (more than needed!?)
	    tombpass=`tomb-kdb-pbkdf2 $pbkdf2_salt $pbkdf2_iter 64 <<<"${tombpass}"`
	    
	    header="_KDF_pbkdf2sha1_${pbkdf2_salt}_${pbkdf2_iter}_64\n"
	}
    }


    print -n $header

    print "${tombpass}" \
	| gpg --openpgp --force-mdc --cipher-algo ${algo} \
	--batch --no-options --no-tty --passphrase-fd 0 --status-fd 2 \
	-o - -c -a ${lukskey}

    unset tombpass
    unset tombpasstmp
}

# 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.
# Requires steghide(1) to be installed
bury_key() {
    tombkey="`option_value -k`"
    imagefile=$1

    { is_valid_key ${tombkey} } || {
	die "Bury failed: not a tomb key $tombkey" }

    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 confirm the key password for the encoding"
    tombpass=`ask_key_password $tombkey`
    { test $? = 0 } || {
	_warning "Wrong password supplied."
	die "You shall not bury a key whose password is unknown to you."
    }

    # we omit armor strings since having them as constants can give
    # ground to effective attacks on steganography

    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() {
    tombkey="`option_value -k`"
    imagefile=$1
    res=1

    file $imagefile | grep JPEG > /dev/null
    if [ $? != 0 ]; then
	_warning "encode failed: $imagefile is not a jpeg image"
	return 1
    fi

    if [[ -e "$tombkey" ]]; then
	_warning "File exists: $tombkey"
	{ option_is_set -f } || {
	    _warning "Make explicit use of --force to overwrite"
	    die "Refusing to overwrite file. Operation aborted." }
	_warning "Use of --force selected: overwriting."
	rm -f ${tombkey}
    fi

    _message "Trying to exhume a key out of image $imagefile"
    if option_is_set --tomb-pwd; then
	    tombpass=`option_value --tomb-pwd`
	    xxx "ask_key_password takes tombpass from CLI argument: $tombpass"
    else
	tombpass=`exec_as_user ${TOMBEXEC} askpass "Steg password for ${tombkey}"`
    fi
	# always steghide required
    steghide extract -sf ${imagefile} -p ${tombpass} -xf ${tombkey}
    res=$?

    unset tombpass

    if [ $res = 0 ]; then
	_success "${tombkey} succesfully decoded"
	return 0
    fi

    _warning "nothing found in $imagefile"
    return 1
}

# Produces a printable image of the key contents so that it can be
# backuped on paper and hidden in books etc.
engrave_key() {
    # load key from options
    tombkey="`load_key $1`"
    { test $? = 0 } || { die "No key specified." }
    keyname=`basename $tombkey`
    pngname="$keyname.qr.png"

    yes "Rendering a printable QRCode for key: $tombkey"
    # we omit armor strings to save space
    awk '
/^-----/ {next}
/^Version/ {next}
{print $0}' ${tombkey} | qrencode --size 4 --level H \
    --casesensitive -o "$pngname"
    { test $? = 0 } || { die "QREncode reported an error." }
    yes "Operation successful:"
    _message "`ls -lh $pngname`"
    _message "`file $pngname`"
}

# }}} - 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() {
    xxx "forge_key()"
    _check_swap

    # can be specified both as simple argument or using -k
    local destkey="$1"
    { option_is_set -k } && { destkey="`option_value -k`" }

    { test "$destkey" = "" } && {
	_warning "no key name specified for creation"
	return 1 }

    { test -r "$destkey" } && {
	_warning "Forging this key would overwrite an existing file. Operation aborted."
	die "`ls -lh $destkey`"    }

    # create the keyfile in tmpfs so that we leave less traces in RAM
    local keytmp=`safe_dir forge`
    (( $? )) && 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

    local algo
    { option_is_set -o } && { algopt="`option_value -o`" }
    algo=${algopt:-AES256}

    _message "Commanded to forge key $destkey with cipher algorithm $algo"

    local tombkey="$destkey"

    _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
    local 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" "$algo" > ${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"
    _check_swap

    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="$1"
    _message "Commanded to lock tomb ${tombfile}"

    tombdir=`dirname $1`
    tombfile=`basename $1`
    tombname=${tombfile%%\.*}

    { test -f ${tombdir}/${tombfile} } || {
	die "There is no tomb here. You have to it dig first."
	return 1 }

    xxx "tomb found: ${tombdir}/${tombfile}"

    nstloop=`losetup -f` # get the number for next loopback device
    losetup -f ${tombdir}/${tombfile} # allocates the next loopback for our file

    xxx "loop mounted on ${nstloop}"

    _message "checking if the tomb is empty (we never step on somebody else's bones)"
    cryptsetup isLuks ${nstloop}
    if [ $? = 0 ]; then
	# is it a LUKS encrypted nest? then bail out and avoid reformatting it
	_warning "The tomb was already locked with another key"
	losetup -d ${nstloop}
	die "Operation aborted. I cannot lock an already locked tomb. Go dig a new one."
    else
	_message "fine, this tomb seems empty."
    fi

    # load key from options or file
    tombkey=`load_key ${tombdir}/${tombfile}.key`
    { test $? = 0 } || {
	losetup -d $nstloop
	die "Aborting operations: error loading key $tombkey" }
	# make sure to call drop_key later

    # the encryption cipher for a tomb can be set when locking using -o
    if option_is_set -o; then
	cipher="`option_value -o`"
    else
	cipher="aes-xts-plain64:sha256"
	# old default was aes-cbc-essiv:sha256
	# for more alternatives refer to cryptsetup(8)
    fi
    _message "locking using cipher: $cipher"

    # get the pass from the user and check it
    tombpass=`ask_key_password "$tombkey"`
    { test $? = 0 } || {
	losetup -d ${nstloop}
	die "No valid password supplied" }

    _success "Locking ${tombfile} with ${tombkey}"

    _message "formatting Luks mapped device"
    get_lukskey "${tombpass}" ${tombkey} | \
	cryptsetup --key-file -   --batch-mode \
	--cipher ${cipher} --key-size 256 --key-slot 0 \
	luksFormat ${nstloop}
    if ! [ $? = 0 ]; then
	_warning "cryptsetup luksFormat returned an error"
	unset tombpass
	losetup -d $nstloop
	die "Operation aborted."
    fi

    get_lukskey "${tombpass}" ${tombkey} | \
	cryptsetup --key-file - \
	--cipher ${cipher} luksOpen ${nstloop} tomb.tmp
    if ! [ $? = 0 ]; then
	_warning "cryptsetup luksOpen returned an error"
	unset tombpass
	losetup -d $nstloop
	die "Operation aborted."
    fi

    # cleanup tombs
    unset tombpass
    drop_key # make sure all temp files are out

    _message "formatting your Tomb with Ext3/Ext4 filesystem"
    ${=MKFS} ${tombname} /dev/mapper/tomb.tmp

    if [ $? != 0 ]; then
	_warning "Tomb format returned an error"
	_warning "your tomb ${tombfile} may be corrupted."
    fi

    sync

    cryptsetup luksClose tomb.tmp
    losetup -d ${nstloop}


    _message "done locking $tombname using Luks dm-crypt ${create_cipher}"
    _success "Your tomb is ready in ${tombdir}/${tombfile} and secured with key ${tombkey}"

}

# This function changes the key that locks a tomb
change_tomb_key() {
    _check_swap

    { option_is_set -k } || { die "Specify the new key with -k" }
    newkey="`option_value -k`"

    { is_valid_key "$newkey" } || {
	die "New key invalid. Check your usage of the --key option." }

    oldkey="$1"
    { is_valid_key "$oldkey" } || {
	die "Old key invalid. Check your usage of the first argument." }

    { is_valid_tomb "$2" } || {
	die "Specify the name of a tomb as second argument" }

    nstloop=`losetup -f`
    { test $? = 255 } && {
	die "Too many tombs are open. Please close any of them to proceed." }
    losetup -f "$2"
    cryptsetup isLuks ${nstloop}
    # is it a LUKS encrypted nest? we check one more timesee cryptsetup(1)
    { test $? = 0 } || {
	losetup -d "$nstloop"
	die "Not a valid LUKS encrypted volume: $2" }

    # we have everything, prepare to mount
    yes "Changing lock on tomb $tombname"
    _message "old key: $oldkey"
    _message "new key: $newkey"

    # render the mapper
    mapdate=`date +%s`
    # save date of mount in minutes since 1970
    mapper="tomb.${tombname}.${mapdate}.`basename $nstloop`"


    # load the new key from the -k option
    tombkey=`load_key`
    { test $? = 0 } || {
	die "Aborting operations: error loading new key $tombkey"    }

    newkeypass=`ask_key_password $tombkey`
    { test $? = 0 } || {
	die "No valid password supplied for the new key" }
    newkeyfile="`safe_filename newkey`"
    get_lukskey "$newkeypass" "$newkey" > $newkeyfile

    # load the old key
    oldkeypass="`ask_key_password $oldkey`"
    { test $? = 0 } || {
	die "No valid password supplied for the old key" }

    # luksOpen the tomb (not really mounting, just on the loopback)
    get_lukskey "$oldkeypass" "$oldkey" | \
	cryptsetup --key-file - luksOpen ${nstloop} ${mapper}
    { test $? = 0 } || {
	losetup -d "$nstloop"
	die "Unexpected error in luksOpen." }

    get_lukskey "$oldkeypass" "$oldkey" | \
	cryptsetup --key-file - luksChangeKey "$nstloop" "$newkeyfile"
    { test $? = 0 } || {
	losetup -d "$nstloop"
	die "Unexpected error in luksChangeKey." }

    cryptsetup luksClose "${mapper}"
    { test $? = 0 } || {
	losetup -d "$nstloop"
	die "Unexpected error in luksClose." }


    drop_key
    unset tombpass
    ${=WIPE} "$newkeyfile"
    losetup -d ${nstloop}

    yes "Succesfully changed key for tomb: $2"
    _message "The new key is: $newkey"

    return 0
}

# backward compatibility
create_tomb() {
    xxx "create_tomb(): ${=@} ${=OLDARGS}"
    if ! [ $1 ]; then
	_warning "no tomb name specified for creation"
	return 1
    fi


    { test -r "$1" } && {
	_warning "Creating this tomb would overwrite an existing file. Operation aborted."
	die "`ls -lh $1`"    }

    { test $? = 0 } || { die "Failed to dig tomb, operation aborted." }


    tombfile=`basename $1`
    tombdir=`dirname $1`
    # make sure the file has a .tomb extension
    tombname=${tombfile%%\.*}
    tombfile=${tombname}.tomb

    ${TOMBEXEC} dig ${=PARAM}
    ${TOMBEXEC} forge ${tombdir}/${tombfile}.key
    { test $? = 0 } || { die "Failed to forge key, operation aborted." }

    ${TOMBEXEC} lock ${tombdir}/${tombfile} -k ${tombdir}/${tombfile}.key
    { test $? = 0 } || { die "Failed to lock tomb with key, operation aborted." }

    yes "Tomb $tombname succesfully created"
    ls -l ${tombfile}*
}
# }}} - Creation

# {{{ Open

# $1 = tombfile $2(optional) = mountpoint
mount_tomb() {
    _message "Commanded to open tomb $1"
    _check_swap

    if ! [ ${1} ]; then
	_warning "no tomb name specified for creation"
	return 1
    fi


    # set up variables to be used
    # the full path is made with $tombdir/$tombfile

    local tombkey
    local tombfile
    local tombdir
    local tombname
    tombfile=`basename ${1}`
    tombdir=`dirname ${1}`
    # check file type (if its a Luks fs)
    file ${tombdir}/${tombfile} | grep -i 'luks encrypted file' 2>&1 >/dev/null
    if [ $? != 0 ]; then
	_warning "$1 is not a valid tomb file, operation aborted"
	return 1
    fi
    tombname=${tombfile%%\.*}
    xxx "tomb found: ${tombdir}/${tombfile}"

    # load_key called here
    tombkey=`load_key ${tombdir}/${tombfile}.key`
    { test $? = 0 } || {
	die "Aborting operations: error loading key $tombkey"    }


    if [ "$2" = "" ]; then
	tombmount=/media/${tombfile}
	_message "mountpoint not specified, using default: $tombmount"
    else
	tombmount=$2
    fi

    # check if its already open
    mount -l | grep "${tombfile}.*\[$tombname\]$" 2>&1 > /dev/null
    if [ $? = 0 ]; then
	_warning "$tombname is already open."
	_message "here below its status is reported:"
	list_tombs ${tombname}
	return 0
    fi

    _success "Opening $tombfile on $tombmount"


    nstloop=`losetup -f`
    if [ $? = 255 ]; then
	die "too many tomb opened. Please close any of them to open another tomb"
    fi
    losetup -f ${tombdir}/${tombfile}

    cryptsetup isLuks ${nstloop}
    if [ $? != 0 ]; then
	# is it a LUKS encrypted nest? see cryptsetup(1)
	_warning "$tombfile is not a valid Luks encrypted storage file"
	losetup -d ${nstloop}
	return 1
    fi
    say "this tomb is a valid LUKS encrypted device"

    luksdump="`cryptsetup luksDump ${nstloop}`"
    tombdump=(`print $luksdump | awk '
	/^Cipher name/ {print $3}
	/^Cipher mode/ {print $3}
	/^Hash spec/   {print $3}'`)
    say "cipher is \"$tombdump[1]\" mode \"$tombdump[2]\" hash \"$tombdump[3]\""

    slotwarn=`print $luksdump | awk '
	BEGIN { zero=0 }
	/^Key slot 0/ { zero=1 }
	/^Key slot.*ENABLED/ { if(zero==1) print "WARN" }'`
    { test "$slotwarn" = "WARN" } && {
	_warning "Multiple key slots are enabled on this tomb. Beware: there can be a backdoor." }

    # save date of mount in minutes since 1970
    mapdate=`date +%s`

    mapper="tomb.${tombname}.${mapdate}.`basename $nstloop`"
    keyname=`basename $tombkey | cut -d. -f1`

    tombpass=`ask_key_password $tombkey`
    { test $? = 0 } || {
	losetup -d ${nstloop}
	die "No valid password supplied" }

    get_lukskey "${tombpass}" ${tombkey} | \
	cryptsetup --key-file - luksOpen ${nstloop} ${mapper}


    # key dropped here
    drop_key
    unset tombpass

    if ! [ -r /dev/mapper/${mapper} ]; then
	losetup -d ${nstloop}
	die "failure mounting the encrypted file"
    fi

    # array: [ cipher, keysize, loopdevice ]
    tombstat=(`cryptsetup status ${mapper} | awk '
    /cipher:/  {print $2}
    /keysize:/ {print $2}
    /device:/  {print $2}'`)
    yes "Success unlocking tomb $tombname"
    xxx "key size is $tombstat[2] for cipher $tombstat[1]"

    _message "checking filesystem via $tombstat[3]"
    fsck -p -C0 /dev/mapper/${mapper}
    xxx "tomb engraved as $tombname"
    tune2fs -L ${tombname} /dev/mapper/${mapper} > /dev/null

    # we need root from here on
    mkdir -p $tombmount

    mount -o $MOUNTOPTS /dev/mapper/${mapper} ${tombmount}

    chown ${_uid}:${_gid} ${tombmount}
    chmod 0750 ${tombmount}

    _success "Success opening $tombfile on $fg_bold[white]$tombmount$fg_no_bold[white]"

    # print out when was opened the last time, by whom and where
    { test -r ${tombmount}/.last } && {
	tombtty="`cat ${tombmount}/.tty`"
	tombhost="`cat ${tombmount}/.host`"
	tombuid="`cat ${tombmount}/.uid`"
	tomblast="`cat ${tombmount}/.last`"
	tombuser=`awk -F: '/:'"$tombuid"':/ {print $1}' /etc/passwd`
	say "last visit by $fg_bold[white]$tombuser($tombuid)$fg_no_bold[white] from $fg_bold[white]$tombtty$fg_no_bold[white] on $fg_bold[white]$tombhost$fg_no_bold[white]"
	say "on date $fg_bold[white]`date --date @${tomblast} +%c`$fg_no_bold[white]"
    }
    # write down the UID and TTY that opened the tomb
    rm -f ${tombmount}/.uid
    echo ${_uid} > ${tombmount}/.uid
    rm -f ${tombmount}/.tty
    echo ${_tty} > ${tombmount}/.tty
    # also the hostname
    rm -f ${tombmount}/.host
    echo `hostname` > ${tombmount}/.host
    # and the "last time opened" information
    # in minutes since 1970, this is printed at next open
    rm -f ${tombmount}/.last
    echo "`date +%s`" > ${tombmount}/.last
    # human readable: date --date=@"`cat .last`" +%c


    # process bind-hooks (mount -o bind of directories)
    # and post-hooks (execute on open)
    if ! option_is_set -n ; then
	exec_safe_bind_hooks ${tombmount}
	exec_safe_post_hooks ${tombmount} open
    fi
    return 0
}

# ## Hooks execution
exec_safe_bind_hooks() {
    if [[ -n ${(k)opts[-o]} ]]; then
	MOUNTOPTS=${opts[-o]}
    fi
    local MOUNTPOINT="${1}"
    local ME=${SUDO_USER:-$(whoami)}
    local HOME=$(awk -v a="$ME" -F ':' '{if ($1 == a) print $6}' /etc/passwd 2>/dev/null)
    if [ $? -ne 0 ]; then
	_warning "how pitiful!  A tomb, and no HOME"
	return 1
    fi
    if [ -z "$MOUNTPOINT" -o ! -d "$MOUNTPOINT" ]; then
	_warning "cannot exec bind hooks without a mounted tomb."
	return 1
    fi
    if ! [ -r "$MOUNTPOINT/bind-hooks" ]; then
	xxx "bind-hooks not found in $MOUNTPOINT"
	return 1
    fi
    typeset -al mounted
    typeset -Al maps
    maps=($(<"$MOUNTPOINT/bind-hooks"))
    for dir in ${(k)maps}; do
	if [ "${dir[1]}" = "/" -o "${dir[1,2]}" = ".." ]; then
	    _warning "bind-hooks map format: local/to/tomb local/to/\$HOME"
	    continue
	fi
	if [ "${${maps[$dir]}[1]}" = "/" -o "${${maps[$dir]}[1,2]}" = ".." ]; then
	    _warning "bind-hooks map format: local/to/tomb local/to/\$HOME.  Rolling back"
	    for dir in ${mounted}; do umount $dir; done
	    return 1
	fi
	if [ ! -r "$HOME/${maps[$dir]}" ]; then
	    _warning "bind-hook target not existent, skipping $HOME/${maps[$dir]}"
	elif [ ! -r "$MOUNTPOINT/$dir" ]; then
	    _warning "bind-hook source not found in tomb, skipping ${MOUNTPOINT}/${dir}"
	else
	    mount -o bind,$MOUNTOPTS $MOUNTPOINT/$dir $HOME/${maps[$dir]}
	    mounted+=("$HOME/${maps[$dir]}")
	fi
    done
}

# Post mount hooks
exec_safe_post_hooks() {
    local mnt=$1 # first argument is where the tomb is mounted
    local ME=${SUDO_USER:-$(whoami)}
    if ! [ -x ${mnt}/post-hooks ]; then return; fi
    # if 'post-hooks' is found inside the tomb, check it: if it is an
    # executable, launch it as a user this might need a dialog for
    # security on what is being run, however we expect you know well
    # what is inside your tomb.  this feature opens the possibility to
    # make encrypted executables.
    cat ${mnt}/post-hooks | head -n1 | grep '^#!/'
    if [ $? = 0 ]; then
	_success "post hooks found, executing as user $SUDO_USER"
	exec_as_user ${mnt}/post-hooks "$2" "$1"
    fi
}

# }}} - Tomb open

# {{{ List

# list all tombs mounted in a readable format
# $1 is optional, to specify a tomb
list_tombs() {

    # list all open tombs
    mounted_tombs=(`list_tomb_mounts $1`)
    { test ${#mounted_tombs} = 0 } && {
	die "I can't see any ${1:-open} tomb, may they all rest in peace." }

    for t in ${mounted_tombs}; do
	mapper=`basename ${t[(ws:;:)1]}`
	tombname=${t[(ws:;:)5]}
	tombmount=${t[(ws:;:)2]}
	tombfs=${t[(ws:;:)3]}
	tombfsopts=${t[(ws:;:)4]}
	tombloop=${mapper[(ws:.:)4]}

	# calculate tomb size
	ts=`df -hP /dev/mapper/$mapper |
    awk "/mapper/"' { print $2 ";" $3 ";" $4 ";" $5 }'`
	tombtot=${ts[(ws:;:)1]}
	tombused=${ts[(ws:;:)2]}
	tombavail=${ts[(ws:;:)3]}
	tombpercent=${ts[(ws:;:)4]}
	tombp=${tombpercent%%%}
	tombsince=`date --date=@${mapper[(ws:.:)3]} +%c`

	# find out who opens it from where
	{ test -r ${tombmount}/.tty } && {
	    tombtty="`cat ${tombmount}/.tty`"
	    tombhost="`cat ${tombmount}/.host`"
	    tombuid="`cat ${tombmount}/.uid`"
	    tombuser=`awk -F: '/:'"$tombuid"':/ {print $1}' /etc/passwd`
	}

    if option_is_set --get-mountpoint; then
	echo $tombmount
	continue
    fi
	# breaking up such strings is good for translation
	print -n "$fg[green]$tombname"
	print -n "$fg[white] open on "
	print -n "$fg_bold[white]$tombmount"
	print -n "$fg_no_bold[white] using "
	print "$fg_bold[white]$tombfs $tombfsopts"

	print -n "$fg_no_bold[green]$tombname"
	print -n "$fg_no_bold[white] open since "
	print "$fg_bold[white]$tombsince$fg_no_bold[white]"

	{ test "$tombtty" = "" } || {
	    print -n "$fg_no_bold[green]$tombname"
	    print -n "$fg_no_bold[white] open by "
	    print -n "$fg_bold[white]$tombuser"
	    print -n "$fg_no_bold[white] from "
	    print -n "$fg_bold[white]$tombtty"
	    print -n "$fg_no_bold[white] on "
	    print "$fg_bold[white]$tombhost"
	}

	print -n "$fg_no_bold[green]$tombname"
	print -n "$fg[white] size "
	print -n "$fg_bold[white]$tombtot"
	print -n "$fg_no_bold[white] of which "
	print -n "$fg_bold[white]$tombused"
	print -n "$fg_no_bold[white] used: "
	print -n "$fg_bold[white]$tombavail"
	print -n "$fg_no_bold[white] free ("
	print -n "$fg_bold[white]$tombpercent"
	print "$fg_no_bold[white] full)"

	if [[ ${tombp} -ge 90 ]]; then
	    print -n "$fg_no_bold[green]$tombname"
	    print "$fg_bold[red] Your tomb is almost full!"
	fi

	# now check hooks
	mounted_hooks=(`list_tomb_binds $tombname`)
	for h in ${mounted_hooks}; do
	    print -n "$fg_no_bold[green]$tombname"
	    print -n "$fg_no_bold[white] hooks "
#	    print -n "$fg_bold[white]`basename ${h[(ws:;:)1]}`"
#	    print -n "$fg_no_bold[white] on "
	    print "$fg_bold[white]${h[(ws:;:)2]}$fg_no_bold[white]"
	done
    done
}


# print out an array of mounted tombs (internal use)
# format is semi-colon separated list of attributes
# if 1st arg is supplied, then list only that tomb
#
# String positions in the semicolon separated array:
#
# 1. full mapper path
#
# 2. mountpoint
#
# 3. filesystem type
#
# 4. mount options
#
# 5. tomb name
list_tomb_mounts() {
    if [ "$1" = "" ]; then
	# list all open tombs
	mount -l \
	    | awk '
BEGIN { main="" }
/^\/dev\/mapper\/tomb/ {
  if(main==$1) next;
  print $1 ";" $3 ";" $5 ";" $6 ";" $7
  main=$1
}
'
    else
	# list a specific tomb
	mount -l \
	    | awk -vtomb="[$1]" '
BEGIN { main="" }
/^\/dev\/mapper\/tomb/ {
  if($7!=tomb) next;
  if(main==$1) next;
  print $1 ";" $3 ";" $5 ";" $6 ";" $7
  main=$1
}
'
    fi
}

# list_tomb_binds
# print out an array of mounted bind hooks (internal use)
# format is semi-colon separated list of attributes
# needs an argument: name of tomb whose hooks belong
list_tomb_binds() {
    if [ "$1" = "" ]; then
	_failure "internal error: list_tomb_binds called without argument."; fi

    # list bind hooks on util-linux 2.20 (Debian 7)
    mount -l \
	| awk -vtomb="$1" '
BEGIN { main="" }
/^\/dev\/mapper\/tomb/ {
  if($7!=tomb) next;
  if(main=="") { main=$1; next; }
  if(main==$1)
    print $1 ";" $3 ";" $5 ";" $6 ";" $7
}
'

    # list bind hooks on util-linux 2.17 (Debian 6)
    tombmount=`mount -l \
      | awk -vtomb="$1" '
/^\/dev\/mapper\/tomb/ { if($7!=tomb) next; print $3; exit; }'`

    mount -l | grep "^$tombmount" \
	| awk -vtomb="$1" '
	/bind/ { print $1 ";" $3 ";" $5 ";" $6 ";" $7 }'
}

# }}} - Tomb list

# {{{ Index and search

# index files in all tombs for search
# $1 is optional, to specify a tomb
index_tombs() {
    { command -v updatedb > /dev/null } || {
	die "Cannot index tombs on this system: updatedb (mlocate) not installed" }

    updatedbver=`updatedb --version | grep '^updatedb'`
    [[ "$updatedbver" =~ "GNU findutils" ]] && {
	_warning "Cannot use GNU findutils for index/search commands" }
    [[ "$updatedbver" =~ "mlocate" ]] || {
	die "Index command needs 'mlocate' to be installed." }

    xxx "$updatedbver"

    mounted_tombs=(`list_tomb_mounts $1`)
    { test ${#mounted_tombs} = 0 } && {
	if [ $1 ]; then die "There seems to be no open tomb engraved as [$1]"
	else die "I can't see any open tomb, may they all rest in peace."
	fi
    }


    yes "Creating and updating search indexes"

    # start the LibreOffice document converter if installed
    { command -v unoconv >/dev/null } && {
	unoconv -l 2>/dev/null &
	xxx "unoconv listener launched"
	sleep 1 }

    for t in ${mounted_tombs}; do
	mapper=`basename ${t[(ws:;:)1]}`
	tombname=${t[(ws:;:)5]}
	tombmount=${t[(ws:;:)2]}
	{ test -r ${tombmount}/.noindex } && {
	    say "skipping $tombname (.noindex found)"
	    continue }
	say "indexing $tombname filenames..."
	updatedb -l 0 -o ${tombmount}/.updatedb -U ${tombmount}

	# here we use swish to index file contents
	{ test $SWISH = 1 } && {
	    say "indexing $tombname contents..."
	    swishrc=`safe_filename swish`

	    cat <<EOF > $swishrc
# index directives
DefaultContents TXT*
IndexDir $tombmount
IndexFile $tombmount/.swish
# exclude images
FileRules filename regex /\.jp.?g/i
FileRules filename regex /\.png/i
FileRules filename regex /\.gif/i
FileRules filename regex /\.tiff/i
FileRules filename regex /\.svg/i
FileRules filename regex /\.xcf/i
FileRules filename regex /\.eps/i
FileRules filename regex /\.ttf/i
# exclude audio
FileRules filename regex /\.mp3/i
FileRules filename regex /\.ogg/i
FileRules filename regex /\.wav/i
FileRules filename regex /\.mod/i
FileRules filename regex /\.xm/i
# exclude video
FileRules filename regex /\.mp4/i
FileRules filename regex /\.avi/i
FileRules filename regex /\.ogv/i
FileRules filename regex /\.ogm/i
FileRules filename regex /\.mkv/i
FileRules filename regex /\.mov/i
# exclude system
FileRules filename is ok
FileRules filename is lock
FileRules filename is control
FileRules filename is status
FileRules filename is proc
FileRules filename is sys
FileRules filename is supervise
FileRules filename regex /\.asc$/i
FileRules filename regex /\.gpg$/i

# pdf and postscript
FileFilter .pdf pdftotext "'%p' -"
FileFilter .ps  ps2txt "'%p' -"
# compressed files
FileFilterMatch lesspipe "%p" /\.tgz$/i
FileFilterMatch lesspipe "%p" /\.zip$/i
FileFilterMatch lesspipe "%p" /\.gz$/i
FileFilterMatch lesspipe "%p" /\.bz2$/i
FileFilterMatch lesspipe "%p" /\.Z$/
# spreadsheets
FileFilterMatch unoconv "-d spreadsheet -f csv --stdout %P" /\.xls.*/i
FileFilterMatch unoconv "-d spreadsheet -f csv --stdout %P" /\.xlt.*/i
FileFilter .ods unoconv "-d spreadsheet -f csv --stdout %P"
FileFilter .ots unoconv "-d spreadsheet -f csv --stdout %P"
FileFilter .dbf unoconv "-d spreadsheet -f csv --stdout %P"
FileFilter .dif unoconv "-d spreadsheet -f csv --stdout %P"
FileFilter .uos unoconv "-d spreadsheet -f csv --stdout %P"
FileFilter .sxc unoconv "-d spreadsheet -f csv --stdout %P"
# word documents
FileFilterMatch unoconv "-d document -f txt --stdout %P" /\.doc.*/i
FileFilterMatch unoconv "-d document -f txt --stdout %P" /\.odt.*/i
FileFilterMatch unoconv "-d document -f txt --stdout %P" /\.rtf.*/i
FileFilterMatch unoconv "-d document -f txt --stdout %P" /\.tex$/i
# native html support
IndexContents HTML* .htm .html .shtml
IndexContents XML*  .xml
EOF

	    xxx "Using swish-e to create index"
	    swish-e -c $swishrc -S fs -v3
	    rm -f $swishrc
	}

	say "search index updated"
    done
}
search_tombs() {
    { command -v locate > /dev/null } || {
	die "Cannot index tombs on this system: updatedb (mlocate) not installed" }

    updatedbver=`updatedb --version | grep '^updatedb'`
    [[ "$updatedbver" =~ "GNU findutils" ]] && {
	_warning "Cannot use GNU findutils for index/search commands" }
    [[ "$updatedbver" =~ "mlocate" ]] || {
	die "Index command needs 'mlocate' to be installed." }

    xxx "$updatedbver"

    # list all open tombs
    mounted_tombs=(`list_tomb_mounts`)
    if [ ${#mounted_tombs} = 0 ]; then
	die "I can't see any open tomb, may they all rest in peace."; fi

    yes "Searching for: $fg_bold[white]${(f)@}$fg_no_bold[white]"
    for t in ${mounted_tombs}; do
	xxx "checking for index: ${t}"
	mapper=`basename ${t[(ws:;:)1]}`
	tombname=${t[(ws:;:)5]}
	tombmount=${t[(ws:;:)2]}
	if [ -r ${tombmount}/.updatedb ]; then

	    # use mlocate to search hits on filenames
	    say "Searching filenames in tomb $tombname"
	    locate -d ${tombmount}/.updatedb -e -i "${(f)@}"
	    say "Matches found: `locate -d ${tombmount}/.updatedb -e -i -c ${(f)@}`"

	    # use swish-e to search over contents
	    { test $SWISH = 1 } && { test -r $tombmount/.swish } && {
		say "Searching contents in tomb $tombname"
		swish-search -w ${=@} -f $tombmount/.swish -H0 }

	else
	    no "skipping tomb $tombname: not indexed"
	    no "run 'tomb index' to create indexes"
	fi
    done
    say "Search completed."
}

# }}} - Index and search

# {{{ Resize

# resize tomb file size
resize_tomb() {
    _message "Commanded to resize tomb $1 to $opts[-s] megabytes"
    if ! [ $1 ]; then
	_failure "No tomb name specified for resizing"
    elif ! [ -r "$1" ]; then
	_failure "Cannot find $1"
    fi
    # $1 is the tomb file path

    local c tombpass tombkey

    tombdir=`dirname $1`
    tombfile=`basename $1`
    tombname=${tombfile%%\.*}

    # load key from options or file
    tombkey=`load_key ${tombdir}/${tombfile}`
    { test $? = 0 } || {
	die "Aborting operations: error loading key $tombkey" }
    # make sure to call drop_key later

    local tmp_resize=`safe_filename resize`
    local newtombsize=$opts[-s]
    local oldtombsize=$(( `stat -c %s "$1" 2>/dev/null` / 1048576 ))
    local mounted_tomb=`mount -l |
	awk -vtomb="[$tombname]" '/^\/dev\/mapper\/tomb/ { if($7==tomb) print $1 }'`

    if [ "$mounted_tomb" ]; then
	_failure "the tomb $tombname is open, to resize it it needs to be close."
    fi

    if ! [ "$newtombsize" ] ; then
	_failure "You must specify the new size of $tombname"
    elif [[ $newtombsize != <-> ]]; then
	_failure "Size is not an integer"
    elif [ "$newtombsize" -le "$oldtombsize" ]; then
	_failure "the new size must be greater then old tomb size."
    fi

    delta="$(( $newtombsize - $oldtombsize ))"

    act "Generating ${tombfile} of ${newtombsize}MiB"

    xxx "Data dump using ${DD[1]} from /dev/urandom"
    ${=DD} if=/dev/urandom bs=1048576 count=${delta} of="${tmp_resize}"

    if [ $? = 0 -a -e "${tmp_resize}" ]; then
	xxx "OK: `ls -lh ${tmp_resize}`"
    else
	_failure "Error creating the extra resize $tmp_resize, operation aborted."
    fi

    cat "${tmp_resize}" >> ${tombdir}/${tombfile}
    rm "${tmp_resize}"


    tombpass=`ask_key_password $tombkey`
    { test $? = 0 } || {
	die "No valid password supplied" }

    local nstloop=`losetup -f`
    if [ $? = 255 ]; then
	_failure "too many tomb opened. Please close any of them to open another tomb"
    fi

    losetup -f ${tombdir}/${tombfile}

    local mapdate=`date +%s`
    local mapper="tomb.${tombname}.${mapdate}.`basename $nstloop`"

    get_lukskey "${tombpass}" ${tombkey} | \
	cryptsetup --key-file - luksOpen ${nstloop} ${mapper}

    unset tombpass
    drop_key # cleanup after load_key

    if ! [ -r /dev/mapper/${mapper} ]; then
	losetup -d ${nstloop}
	_failure "failure mounting the encrypted file"
    fi

    cryptsetup resize "${mapper}"
    if [ $? != 0 ]; then
	losetup -d ${nstloop}
	_failure "cryptsetup failed to resize $mapper"
    fi

    e2fsck -f /dev/mapper/${mapper}
    if [ $? != 0 ]; then
	losetup -d ${nstloop}
	_failure "e2fsck failed to check $mapper"
    fi

    resize2fs /dev/mapper/${mapper}
    if [ $? != 0 ]; then
	losetup -d ${nstloop}
	_failure "resize2fs failed to resize $mapper"
    fi

    sleep 1 # needs to settle a bit

    # close and free the loop device
    cryptsetup luksClose "${mapper}"
    losetup -d ${nstloop}

    return 0
}

# }}}

# {{{ Close

umount_tomb() {
    local tombs how_many_tombs
    local pathmap mapper tombname tombmount loopdev
    local ans pidk pname

    if [ "$1" = "all" ]; then
	mounted_tombs=(`list_tomb_mounts`)
    else
	mounted_tombs=(`list_tomb_mounts $1`)
    fi

    { test ${#mounted_tombs} = 0 } && {
	    _warning "There is no open tomb to be closed"
	    return 1 }

    { test ${#mounted_tombs} -gt 1 } && { test "$1" = "" } && {
	    _warning "Too many tombs mounted, please specify one (see tomb list)"
	    _warning "or issue the command 'tomb close all' to close them all."
	    return 1 }

    say "Tomb close $1"

    for t in ${mounted_tombs}; do
	mapper=`basename ${t[(ws:;:)1]}`
	tombname=${t[(ws:;:)5]}
	tombmount=${t[(ws:;:)2]}
	tombfs=${t[(ws:;:)3]}
	tombfsopts=${t[(ws:;:)4]}
	tombloop=${mapper[(ws:.:)4]}

	xxx "name: $tombname"
	xxx "mount: $tombmount"
	xxx "mapper: $mapper"

	{ test -e "$mapper" } && {
	    _warning "Tomb not found: $1"
	    _warning "Please specify an existing tomb."
	    return 0 }

	if [ $SLAM ]; then
	    _success "Slamming tomb $tombname mounted on $tombmount"
	    _message "Kill all processes busy inside the tomb"
	    if ! slam_tomb "$tombmount"; then
		_warning "Cannot slam the tomb $tombname"
		return 1
	    fi
	else
	    say "Closing tomb $tombname mounted on $tombmount"
	fi

    # check if there are binded dirs and close them
	bind_tombs=(`list_tomb_binds $tombname`)
	for b in ${bind_tombs}; do
	    bind_mapper="${b[(ws:;:)1]}"
	    bind_mount="${b[(ws:;:)2]}"
	    _message "closing tomb bind hook: $bind_mount"
	    umount $bind_mount
	    if [[ $? != 0 ]]; then
		if [ $SLAM ]; then
		    _success "Slamming tomb: killing all processes using this hook"
		    slam_tomb "$bind_mount"
		    if [[ $? == 1 ]]; then
			_warning "Cannot slam the bind hook $bind_mount"
			return 1
		    fi
		    umount $bind_mount
		else
		    _warning "Tomb bind hook $bind_mount is busy, cannot close tomb."
		fi
	    fi
	done

    # Execute post-hooks for eventual cleanup
	if ! option_is_set -n ; then
	    exec_safe_post_hooks ${tombmount%%/} close
	fi

	xxx "performing umount of $tombmount"
	umount ${tombmount}
	if ! [ $? = 0 ]; then _warning "Tomb is busy, cannot umount!"
	else
	# this means we used a "default" mount point
	    { test "${tombmount}" = "/media/${tombname}.tomb" } && {
		rmdir ${tombmount} }
	fi

	cryptsetup luksClose $mapper
	{ test $? = 0 } || {
	    _warning "error occurred in cryptsetup luksClose ${mapper}"
	    return 1 }

	losetup -d "/dev/$tombloop"

	_success "Tomb $tombname closed: your bones will rest in peace."

    done # loop across mounted tombs

    return 0
}

# Kill all processes using the tomb
slam_tomb() {
    # $1 = tomb mount point
    if [[ -z `fuser -m "$1" 2> /dev/null` ]]; then
	return 0
    fi
    #Note: shells are NOT killed by INT or TERM, but they are killed by HUP
    for s in TERM HUP KILL; do
	xxx "Sending $s to processes inside the tomb:"
	if option_is_set -D; then
	    ps -fp `fuser -m /media/a.tomb 2> /dev/null`|
	    while read line; do
		xxx $line
	    done
	fi
	fuser -s -m "$1" -k -M -$s
	if [[ -z `fuser -m "$1" 2> /dev/null` ]]; then
	    return 0
	fi
	if ! option_is_set -f; then
	    sleep 3
	fi
    done
    return 1
}

# }}} - Tomb close

# {{{ Main routine

main() {
    local -A subcommands_opts
    ### Options configuration

    # Hi, dear developer! Are you trying to add a new subcommand, or
    # to add some options?  Well, keep in mind that an option CAN'T
    # have differente meanings/behaviour in different subcommands.

    # For example, "-s" means "size" and accept an argument. If you are tempted to add
    # an option "-s" (that means, for example "silent", and doesn't accept an argument)
    #           DON'T DO IT!

    #  There are two reasons for that:
    #       I. usability; user expect that "-s" is "size"
    #    II. Option parsing WILL EXPLODE if you do this kind of bad things
    #            (it will say "option defined more than once, and he's right")
    #
    #    If you want to use the same option in multiple commands then
    #    you can only use the non-abbreviated long-option version like:
    #    -force and NOT -f
    main_opts=(q -quiet=q D -debug=D h -help=h v -version=v U: -uid=U G: -gid=G T: -tty=T -no-color -unsecure-dev-mode)
    subcommands_opts[__default]=""
    subcommands_opts[open]="f -force n -nohook=n k: -key=k o: -ignore-swap -sudo-pwd: -tomb-pwd: "
    subcommands_opts[mount]=${subcommands_opts[open]}

    subcommands_opts[create]="" # deprecated, will issue warning

    subcommands_opts[forge]="f -force -ignore-swap k: -key=k -kdf: o: -tomb-pwd: -use-urandom "
    subcommands_opts[dig]="f -force -ignore-swap s: -size=s "
    subcommands_opts[lock]="f -force -ignore-swap k: -key=k o: -sudo-pwd: -tomb-pwd: "
    subcommands_opts[setkey]="f -force -ignore-swap k: -key=k -sudo-pwd: -tomb-pwd: "
    subcommands_opts[engrave]="k: -key=k "

    subcommands_opts[passwd]="f -ignore-swap -kdf: -tomb-old-pwd: -tomb-pwd: "
    subcommands_opts[close]="-sudo-pwd: "
    subcommands_opts[help]=""
    subcommands_opts[slam]=""
    subcommands_opts[list]="-get-mountpoint "

    subcommands_opts[index]=""
    subcommands_opts[search]=""

    subcommands_opts[help]=""
    subcommands_opts[bury]="f -force k: -key=k -tomb-pwd: "
    subcommands_opts[exhume]="f -force k: -key=k -tomb-pwd: "
    # subcommands_opts[decompose]=""
    # subcommands_opts[recompose]=""
    # subcommands_opts[install]=""
    subcommands_opts[askpass]=""
    subcommands_opts[mktemp]=""
    subcommands_opts[source]=""
    subcommands_opts[resize]="f -force -ignore-swap s: -size=s k: -key=k -tomb-pwd: "
    subcommands_opts[check]="-ignore-swap "
#    subcommands_opts[translate]=""

    ### Detect subcommand
    local -aU every_opts #every_opts behave like a set; that is, an array with unique elements
    for optspec in $subcommands_opts$main_opts; do
	for opt in ${=optspec}; do
	    every_opts+=${opt}
	done
    done
    local -a oldstar
    oldstar=($argv)
	#### detect early: useful for --optiion-parsing
    zparseopts -M -D -Adiscardme ${every_opts}
	if [[ -n ${(k)discardme[--option-parsing]} ]]; then
		echo $1
		if [[ -n "$1" ]]; then
			return 1
		fi
		return 0
	fi
	unset discardme
    if ! zparseopts -M -E -D -Adiscardme ${every_opts}; then
		die "error parsing"
		return 127
	fi
    unset discardme
    subcommand=$1
    if [[ -z $subcommand ]]; then
	subcommand="__default"
    fi

    if [[ -z ${(k)subcommands_opts[$subcommand]} ]]; then
	_warning "There's no such command \"$subcommand\"."
	_failure "Please try -h for help" 127
#        die "Subcommand '$subcommand' doesn't exist" 127
    fi
    argv=(${oldstar})
    unset oldstar

    ### Parsing global + command-specific options
    # zsh magic: ${=string} will split to multiple arguments when spaces occur
    set -A cmd_opts ${main_opts} ${=subcommands_opts[$subcommand]}
    # if there is no option, we don't need parsing
    if [[ -n $cmd_opts ]]; then
	zparseopts -M -E -D -Aopts ${cmd_opts}
	if [[ $? != 0 ]]; then
	    _warning "Some error occurred during option processing."
	    die "See \"tomb help\" for more info" 127
	fi
    fi
    #build PARAM (array of arguments) and check if there are unrecognized options
    ok=0
    PARAM=()
    for arg in $*; do
	if [[ $arg == '--' || $arg == '-' ]]; then
	    ok=1
	    continue #it shouldnt be appended to PARAM
	elif [[ $arg[1] == '-'  ]]; then
	    if [[ $ok == 0 ]]; then
		die "unrecognized option $arg for subcommand $subcommand" 127
	    fi
	fi
	PARAM+=$arg
    done
    #first parameter actually is the subcommand: delete it and shift
    if [[ $subcommand != '__default' ]]; then
	PARAM[1]=()
	shift
    fi
    ### End parsing command-specific options
    if ! option_is_set --no-color; then
	autoload colors; colors
    fi
    if ! option_is_set --unsecure-dev-mode; then
	for opt in --sudo-pwd --tomb-pwd --use-urandom --tomb-old-pwd; do
	    if option_is_set $opt; then
		die "You specified option $opt, which is DANGEROUS and should only be used for testing\nIf you really want so, add --unsecure-dev-mode" 127
	    fi
	done
    fi

    # when we run as root, we remember the original uid:gid
    # to set permissions for the calling user and drop privileges
    if option_is_set -U; then _uid="`option_value -U`"; fi
    if option_is_set -G; then _gid="`option_value -G`"; fi
    if option_is_set -T; then _tty="`option_value -T`"; fi

    xxx "Tomb command: $subcommand ${PARAM}"
    xxx "caller uid[$_uid] gid[$_gid] tty[$_tty]"

    case "$subcommand" in

	# new creation in three steps
	forge)
	    check_priv
	    forge_key ${=PARAM}
	    ;;
	dig)
	    dig_tomb ${=PARAM}
	    ;;
	lock)
	    check_priv
	    lock_tomb_with_key ${=PARAM}
	    ;;

	setkey)
	    check_priv
	    change_tomb_key ${=PARAM}
	    ;;

	engrave)
	    { test "$QRENCODE" = 0 } && {
		die "QREncode not installed: cannot engrave keys on paper." }
	    engrave_key ${=PARAM}
	    ;;

	# backward compat
	create)
	    _warning "The create command is deprecated, please use dig, forge and lock instead."
	    _warning "For more informations see Tomb's manual page (man tomb)."
	    ;;

	mount|open)
	    check_priv
	    mount_tomb $PARAM[1] $PARAM[2]
	    ;;
	umount|close|slam)
	    check_priv
	    [ "$subcommand" =  "slam" ] && SLAM=1
	    umount_tomb $PARAM[1]
	    ;;
	passwd)
	    change_passwd $PARAM[1]
	    ;;
	list)
	    list_tombs $PARAM[1]
	    ;;

	index)
	    index_tombs $PARAM[1]
	    ;;
	search)
	    search_tombs ${=PARAM}
	    ;;

	help)
	    usage
	    ;;
	bury)
	    { test "$STEGHIDE" = 0 } && {
		die "Steghide not installed: cannot bury keys into images." }
	    bury_key $PARAM[1]
	    ;;
	exhume)
	    { test "$STEGHIDE" = 0 } && {
		die "Steghide not installed: cannot exhume keys from images." }
	    exhume_key $PARAM[1]
	    ;;
	resize)
	    { test "$RESIZER" = 0 } && {
		die "Resize2fs not installed: cannot resize tombs." }
	    check_priv
	    resize_tomb $PARAM[1]
	    ;;

	# internal commands useful to developers
	'source')   return 0 ;;
	install)    check_priv ; install_tomb ;;
	askpass)    ask_password $PARAM[1] $PARAM[2] ;;
	mktemp)     safe_dir $PARAM[1] ;;
	translate)  generate_translatable_strings ;;

	__default)
	    cat <<EOF
Tomb $VERSION - a strong and gentle undertaker for your secrets

 Copyright (C) 2007-2013 Dyne.org Foundation, License GNU GPL v3+
 This is free software: you are free to change and redistribute it
 The latest Tomb sourcecode is published on <http://tomb.dyne.org>
EOF
	    option_is_set -v && {
		cat <<EOF
 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.

System utils:

 `sudo -V | head -n1`
 `cryptsetup --version`
 `pinentry --version`
 `gpg --version | head -n1` - key forging algorithms (GnuPG symmetric ciphers):
`list_gnupg_ciphers`
EOF
		return 0
	    }
	    usage
	    ;;
	*)
	    _warning "command \"$subcommand\" not recognized"
	    _message "try -h for help"
	    return 1
	    ;;
    esac
    return $?
}

# }}}

# {{{ Run
check_bin

main $@
ret=$?
if [[ $ret != 0 ]]; then #this "if" seems useless, but avoid source tomb source from exiting
    exit $ret
fi
# }}}

# -*- tab-width: 4; indent-tabs-mode:nil; -*-
# vim: set shiftwidth=4 expandtab: