# vim: set ft=sh:
# TODO this one needs some work to work with lots of different
#       encryption schemes
run_hook ()
{
    /sbin/modprobe -a -q dm-crypt >/dev/null 2>&1
    if [ -e "/sys/class/misc/device-mapper" ]; then
        if [ ! -c "/dev/mapper/control" ]; then
            read dev_t < /sys/class/misc/device-mapper/dev
            /bin/mknod "/dev/mapper/control" c $(/bin/replace "${dev_t}" ':')
        fi
        [ "${quiet}" = "y" ] && CSQUIET=">/dev/null"

        # Get keyfile if specified
        ckeyfile="/crypto_keyfile.bin"
        if [ "x${cryptkey}" != "x" ]; then
            set -- $(/bin/replace "${cryptkey}" ':'); ckdev=$1; ckarg1=$2; ckarg2=$3
            if poll_device "${ckdev}" ${rootdelay}; then
                case ${ckarg1} in
                    *[!0-9]*)
                        # Use a file on the device
                        # ckarg1 is not numeric: ckarg1=filesystem, ckarg2=path
                        mkdir /ckey
                        mount -r -t ${ckarg1} ${ckdev} /ckey
                        dd if=/ckey/${ckarg2} of=${ckeyfile} >/dev/null 2>&1
                        umount /ckey
                        ;;
                    *)
                        # Read raw data from the block device
                        # ckarg1 is numeric: ckarg1=offset, ckarg2=length
                        dd if=${ckdev} of=${ckeyfile} bs=1 skip=${ckarg1} count=${ckarg2} >/dev/null 2>&1
                        ;;
                esac
            fi
            [ ! -f ${ckeyfile} ] && echo "Keyfile could not be opened. Reverting to passphrase."
        fi

        if [ -n "${cryptdevice}" ]; then
            DEPRECATED_CRYPT=0
            set -- $(/bin/replace "${cryptdevice}" ':'); cryptdev="$1"; cryptname="$2";
        else
            DEPRECATED_CRYPT=1
            cryptdev="${root}"
            cryptname="root"
        fi

        warn_deprecated() {
            echo "The syntax 'root=${root}' where '${root}' is an encrypted volume is deprecated"
            echo "Use 'cryptdevice=${root}:root root=/dev/mapper/root' instead."
        }

        if  poll_device "${cryptdev}" ${rootdelay}; then
            if /bin/cryptsetup isLuks ${cryptdev} >/dev/null 2>&1; then
                [ ${DEPRECATED_CRYPT} -eq 1 ] && warn_deprecated
                dopassphrase=1
                # If keyfile exists, try to use that
                if [ -f ${ckeyfile} ]; then
                    if eval /bin/cryptsetup --key-file ${ckeyfile} luksOpen ${cryptdev} ${cryptname} ${CSQUIET}; then
                        dopassphrase=0
                    else
                        echo "Invalid keyfile. Reverting to passphrase."
                    fi
                fi
                # Ask for a passphrase
                if [ ${dopassphrase} -gt 0 ]; then
                    echo ""
                    echo "A password is required to access the ${cryptname} volume:"

                    #loop until we get a real password
                    while ! eval /bin/cryptsetup luksOpen ${cryptdev} ${cryptname} ${CSQUIET}; do
                        sleep 2;
                    done
                fi
                if [ -e "/dev/mapper/${cryptname}" ]; then
                    if [ ${DEPRECATED_CRYPT} -eq 1 ]; then
                        export root="/dev/mapper/root"
                    fi
                else
                    err "Password succeeded, but ${cryptname} creation failed, aborting..."
                    exit 1
                fi
            elif [ "x${crypto}" != "x" ]; then
                [ ${DEPRECATED_CRYPT} -eq 1 ] && warn_deprecated
                do_oldcrypto ()
                {
                    if [ $# -ne 5 ]; then
                        err "Verify parameter format: crypto=hash:cipher:keysize:offset:skip"
                        err "Non-LUKS decryption not attempted..."
                        return 1
                    fi
                    exe="/bin/cryptsetup create ${cryptname} ${cryptdev}"
                    [ "x$(eval echo ${1})" != "x" ] && exe="${exe} --hash \"$(eval echo ${1})\""
                    [ "x$(eval echo ${2})" != "x" ] && exe="${exe} --cipher \"$(eval echo ${2})\""
                    [ "x$(eval echo ${3})" != "x" ] && exe="${exe} --key-size \"$(eval echo ${3})\""
                    [ "x$(eval echo ${4})" != "x" ] && exe="${exe} --offset \"$(eval echo ${4})\""
                    [ "x$(eval echo ${5})" != "x" ] && exe="${exe} --skip \"$(eval echo ${5})\""
                    if [ -f ${ckeyfile} ]; then
                        exe="${exe} --key-file ${ckeyfile}"
                    else
                        exe="${exe} --verify-passphrase"
                        echo ""
                        echo "A password is required to access the ${cryptname} volume:"
                    fi
                    eval "${exe} ${CSQUIET}"
                }

                msg "Non-LUKS encrypted device found..."
                do_oldcrypto $(/bin/replace -q "${crypto}" ':')

                if [ $? -ne 0 ]; then
                    err "Non-LUKS device decryption failed. verify format: "
                    err "      crypto=hash:cipher:keysize:offset:skip"
                    exit 1
                fi
                if [ -e "/dev/mapper/${cryptname}" ]; then
                    if [ ${DEPRECATED_CRYPT} -eq 1 ]; then
                        export root="/dev/mapper/root"
                    fi
                else
                    err "Password succeeded, but ${cryptname} creation failed, aborting..."
                    exit 1
                fi
            else
                err "Failed to open encryption mapping: The device ${cryptdev} is not a LUKS volume and the crypto= paramater was not specified."
            fi
        fi
        nuke ${ckeyfile}
    fi
}