#!/bin/bash
# This is a script to work with an encrypted gnucash file. It asks for the
# password, decrypts the file, runs gnucash, and encrypts it back. Logs and
# backups are shredded at the end.
# Author: pluton <[email protected]>
# Version: 0.9 (Thu Dec 16 2010)
# License: GNU GPL 3

CP=/bin/cp
KDIALOG=/usr/bin/kdialog
OPENSSL=/usr/bin/openssl
GNUCASH=/usr/bin/gnucash
SHRED=/bin/shred
BASENAME=/usr/bin/basename
CHMOD=/bin/chmod

FILE=~/your_encrypted_file
FILETMP="${FILE}.tmp"
TIMEOUT=2   # seconds
TITLE=$($BASENAME $0)

notify() {
    < -n "$1" > && text="$1" || text="?"
    $KDIALOG --passivepopup "$text" --title "$TITLE" $TIMEOUT
}

< -e "$FILE" > || { notify "File '$FILE' was not found"; exit 1; }

pass=$($KDIALOG --password "Enter the password /GC/")
< "$pass" == "" > && { notify "The password is empty"; exit 2; }

$OPENSSL enc -d -aes-256-cbc -k "$pass" -in "$FILE" -out "$FILETMP" || \
    { notify "The password seems to be wrong"; exit 3; }
$CHMOD go= "$FILETMP"
$CP -f "$FILE" "${FILE}.bkp"
$GNUCASH "$FILETMP"
$OPENSSL enc -e -aes-256-cbc -k "$pass" -in "$FILETMP" -out "$FILE" || \
    { notify "An error occured while encoding (code #$?)"; exit 4; }
unset pass
$SHRED -zun 2 "${FILETMP}"*
notify "Done"