cryptmount 4.5-1 / usr / sbin / cryptmount-setup

#!/bin/sh
# simple setup script for cryptmount
# RW Penney, May 2007

# This file is part of 'cryptmount' and is therefore
# supplied with NO WARRANTY of any form.
# Please see the file 'COPYING' in the main cryptmount source directory
# for further information.

CM_BINEXE="/usr/bin/cryptmount"
CM_CFGDIR="@ETCDIR@"


# prepare gettext internationalization:
TEXTDOMAIN="cryptmount"
export TEXTDOMAIN
TEXTDOMAINDIR="/usr/share/locale"
export TEXTDOMAINDIR
if which gettext.sh > /dev/null 2>&1; then
    . gettext.sh
else
    eval_gettext() {
        eval "echo \"$1\"";
    }
fi


FoldLines() {
    # wrap text-output to fit into 70-columns, breaking on whitespace
    fold -s -w 70
}

ToLowerCase() {
    # translate upper-case letters to lower-case
    tr '[:upper:]' '[:lower:]'
}

TrapCleanup() {
    # try to mitigate any damage if terminated prematurely
    ProgName="$0"
    eval_gettext "Abandoning \$ProgName ..."; echo
    exit 2
}


CheckPrivileges() {
    if [ "`whoami`" != "root" ]; then
        echo ""
        eval_gettext "This script must be run with superuser privileges - please try again, e.g. using one of the following:" | FoldLines; echo
        echo "    sudo $0"
        echo "    su -c $0"
        echo ""
        exit 1
    fi
}


SectionBreak() {
    echo ""
    case "$1" in
        minor)  ;;
        major)
            echo "------------------------------"
            ;;
        *)
            echo ""
            ;;
    esac
}


GetResponse() {
    # Issue prompt string & await response from user
    # syntax: GetResponse <prompt> <default_val> <variable>
    echo ""
    echo "  $1"
    echo -n "  [$2]: "
    read resp
    if [ -z "${resp}" ]; then
        resp="$2"
    fi
    eval "$3=\"${resp}\""
}


GuessHome() {
    # Try to guess user's home-directory, even after su/sudo
    guessed_home="${HOME}"
    if [ "${user_owner}" != "" ]; then
        eval "guessed_home=~${user_owner}"
    fi
    for tgt in "${guessed_home}" "${HOME}" "`pwd`" "/home"; do
        hm="`echo ${tgt}/ | sed -n -e 's%^\(/.*home/[^/]*\).*$%\1%p'`"
        if [ "${hm}" != "" -a -d "${hm}" ]; then
            guessed_home="`echo ${hm} | sed 's%/$%%'`"
            break
        fi
    done
}


CanonVars() {
    # Canonicalize string variables
    for var in $@; do
        eval "val=\"\$${var}\""
        eval "$var=\"`echo \"${val}\" | sed 's, ,\\\\ ,g'`\""
    done
}


GetTargetName() {
    DefaultTargetName=`eval_gettext "opaque"`
    eval_gettext "Each cryptmount filesystem is identifed by a short name which is used when mounting or configuring that filesystem. This name should be a single word (without spaces), such as \"\${DefaultTargetName}\"." | FoldLines; echo
    eval_gettext "The following target names have already been used:"
    echo -n "    "
    tgts=`${CM_BINEXE} --list | awk '{printf"%s ", $1}'`
    if [ ! -z "${tgts}" ]; then echo "${tgts}"; else echo "(NONE)"; fi

    TargetName=""
    while [ -z "${TargetName}" ]; do
        prompt=`eval_gettext "Please enter a target name for your filesystem"`
        GetResponse "${prompt}" "${DefaultTargetName}" "TargetName"

        if ${CM_BINEXE} --list "${TargetName}" >/dev/null 2>&1; then
            eval_gettext "The target-name \"\${TargetName}\" has already been used"
            TargetName=""
        fi
    done
}


GetUser() {
    eval_gettext "The \${TargetName} filesystem can be configured to be owned by a nominated user, who will be able to create top-level files & directories without needing to involve the superuser." | FoldLines; echo

    prompt=`eval_gettext "Which user should own the filesystem (leave blank for \"root\")"`
    GetResponse "${prompt}" "" "user_owner"
}


GetMountPoint() {
    eval_gettext "In order to access the \${TargetName} filesystem, it must be mounted on top of an empty directory." | FoldLines; echo

    mount_dir=""
    while [ -z "${mount_dir}" ]; do
        prompt=`eval_gettext "Please specify where \"\\\${TargetName}\" should be mounted"`
        GetResponse "${prompt}" "${guessed_home}/crypt" "mount_dir"

        if [ -e "${mount_dir}" -a ! -d "${mount_dir}" ]; then
            eval_gettext "\${mount_dir} is not a valid directory name"; echo
            mount_dir=""
        fi
    done
}


GetContainerInfo() {
    eval_gettext "The maximum available size of your filesystem needs to be chosen so that enough space can be reserved on your disk." | FoldLines; echo

    fs_size=""
    while [ -z "${fs_size}" ]; do
        prompt=`eval_gettext "Enter the filesystem size (in MB)"`
        GetResponse "${prompt}" "64" "fs_size"
        if [ "${fs_size}" -gt 0 ] 2>/dev/null; then
            true
        else
            eval_gettext "\${fs_size} is not a valid number"; echo
            fs_size=""
        fi
    done

    SectionBreak
    eval_gettext "The actual encrypted filesystem will be stored in a special file, which needs to be large enough to contain your entire encrypted filesystem." | FoldLines; echo

    crypto_dev=""
    while [ -z "${crypto_dev}" ]; do
        prompt=`eval_gettext "Enter a filename for your encrypted container"`
        GetResponse "${prompt}" "${guessed_home}/crypto.fs" "crypto_dev"

        if [ -e "${crypto_dev}" ]; then
            eval_gettext "WARNING: \${crypto_dev} already exists"; echo
            crypto_dev=""
        fi
    done
}


GetKeyInfo() {
    eval_gettext "Access to your encrypted filesystem is protected by a key that is kept in a separate small file. The key is locked by a password that you must enter whenever you mount the filesystem." | FoldLines; echo

    key_file=""
    while [ -z "${key_file}" ]; do
        prompt=`eval_gettext "Enter a location for the keyfile"`
        GetResponse "${prompt}" "${CM_CFGDIR}/${TargetName}.key" "key_file"

        if [ -e "${key_file}" ]; then
            eval_gettext "WARNING: \${key_file} already exists"; echo
            key_file=""
        fi
    done
}


BuildFS() {
    bckp_cmtab="${CM_CFGDIR}/cmtab.bckp-setup"

    SectionBreak major
    eval_gettext "Your filing system is now ready to be built - this will involve:" | FoldLines; echo ""
    eval_gettext " - Creating the directory \"\${mount_dir}\""; echo
    eval_gettext " - Creating a \${fs_size}MB file, \"\${crypto_dev}\""; echo
    eval_gettext " - Adding an extra entry (\"\${TargetName}\") in \${CM_CFGDIR}/cmtab"; echo
    eval_gettext " - Creating a key-file (\"\${key_file}\")"; echo
    eval_gettext " - Creating an ext3 filingsystem on \"\${crypto_dev}\""; echo

    if [ -f "${bckp_cmtab}" ]; then
        eval_gettext " - Overwriting the backup configuration-file \"\${bckp_cmtab}\""; echo
    fi
    eval_gettext "If you do not wish to proceed, no changes will be made to your system."; echo
    AffirmativeResponse=`eval_gettext "yes" | ToLowerCase`
    NegativeResponse=`eval_gettext "no"`
    prompt=`eval_gettext "Please confirm that you want to proceed (enter \"\\\${AffirmativeResponse}\")"`
    GetResponse "${prompt}" "${NegativeResponse}" "confirm"
    if [ "`echo ${confirm} | ToLowerCase`" != "${AffirmativeResponse}" ]; then
        eval_gettext "Installation abandoned"; echo
        exit 1
    fi

    Completed=`eval_gettext "done"`
    set -e
    eval_gettext "Making mount-point (\${mount_dir})..."
    mkdir -p "${mount_dir}"
    echo " ${Completed}"
    eval_gettext "Creating filesystem container (\${crypto_dev})..."
    pfx=`dirname "${crypto_dev}"`
    test -d "${pfx}" || mkdir -p "${pfx}"
    dd if=/dev/zero of="${crypto_dev}" bs=1M count="${fs_size}" >/dev/null 2>&1
    echo " ${Completed}"
    eval_gettext "Taking backup of cryptmount master config-file (\${bckp_cmtab})..."
    mv "${CM_CFGDIR}/cmtab" "${bckp_cmtab}"
    echo " ${Completed}"
    cat "${bckp_cmtab}" > "${CM_CFGDIR}/cmtab"
    cat <<EOF >> "${CM_CFGDIR}/cmtab"

# Entry automatically generated by setup-script:
`echo "${TargetName}" | sed 's, ,\\\\ ,g'` {
    dev=`echo "${crypto_dev}" | sed 's, ,\\\\ ,g'`
    dir=`echo "${mount_dir}" | sed 's, ,\\\\ ,g'`
    fstype=ext3
    mountoptions=defaults
    cipher=aes
    keyformat=builtin
    keyfile=`echo "${key_file}" | sed 's, ,\\\\ ,g'`
}
EOF
    eval_gettext "Generating filesystem access key (\${key_file})..."; echo
    ${CM_BINEXE} --generate-key 32 "${TargetName}"
    eval_gettext "Formatting encrypted filesystem..."; echo
    ${CM_BINEXE} --prepare "${TargetName}"
    mke2fs -j "/dev/mapper/${TargetName}" >/dev/null 2>&1
    if [ "${user_owner}" != "" ]; then
        chown "${user_owner}" "${mount_dir}" "${crypto_dev}"
        chmod 0500 "${mount_dir}"
        chmod 0600 "${crypto_dev}"
        mount "/dev/mapper/${TargetName}" "${mount_dir}"
        chown "${user_owner}" "${mount_dir}"
        chmod 0700 "${mount_dir}"
        umount "${mount_dir}"
    fi
    (udevadm settle || udevsettle || sleep 5) 2>/dev/null
    ${CM_BINEXE} --release "${TargetName}"
}



#
# Main program
#

SectionBreak major
eval_gettext "cryptmount setup script"; echo; echo

eval_gettext "This program will allow you to setup a secure filing-system that will be managed by \"cryptmount\". You will be able to select basic features such as the location and size of the filesystem - if you want more advanced features, you should consult the cryptmount manual page." | FoldLines; echo; echo

echo "cryptmount version 4.5, (C)Copyright 2007-2009 RW Penney"
eval_gettext "cryptmount comes with ABSOLUTELY NO WARRANTY."; echo
eval_gettext "This is free software, and you are welcome to redistribute it under certain conditions - see the file 'COPYING' in the source directory." | FoldLines; echo


CheckPrivileges
modprobe -q -a loop dm-mod dm-crypt || true
trap TrapCleanup INT QUIT HUP


# Interactively gather configuration information from user:
SectionBreak major
GetTargetName
SectionBreak
GetUser
GuessHome
SectionBreak
GetMountPoint
SectionBreak
GetContainerInfo
SectionBreak
GetKeyInfo

# Build filesystem:
BuildFS

SectionBreak major

eval_gettext "Your new encrypted filesystem is now ready for use - to access, try:" | FoldLines; echo
echo "    cryptmount ${TargetName}"
echo "    cd ${mount_dir}"
eval_gettext "After you have finished using the filesystem, try:" | FoldLines; echo
echo "    cd"
echo "    cryptmount --unmount ${TargetName}"

echo
eval_gettext "Please take great care NOT to delete or damage your keyfile (\"${key_file}\"). Without that file, and the associated password, it will be virtually impossible to access your encrypted filesystem. You may want to keep a separate backup copy of the keyfile." | FoldLines; echo

exit 0

# vim: set ts=4 sw=4 et: