#!/bin/bash
# auth2aes wraps "openssl enc" protect a file with a password
# with aes-256-cbc, with a pbkdf2-derived key.
# This file could be a ~/.bash_aliases or source'd from another script.
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# This program 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. See the
# GNU General Public License for more details.
# You should have received a copy of the GNU General Public License
# along with this program. If not, see .
# Copyright © 2021 Ludovic Pouzenc
alias auth2aes="_auth2aes e"
alias aes2auth="_auth2aes d"
_auth2aes() {
local aespass
local aespass2
local res
local out
local status=0
local iterations=XXX #TODO Choose a number > 800000 here, should be ~1 sec of CPU workload
local action="$1"; shift
# Minimal "usage" / help if called without any args
if [[ $# -eq 0 || ( "e" != "$action" && "d" != "$action" ) ]]; then
echo "Usage: auth2aes ..." >&2
echo " aes2auth ..." >&2
return 1
fi
# Interactive password input (2 times if encrypt)
read -sp "Please enter the password to derive the key from (undisplayed): " aespass
res=$?; echo
if [[ $res -ne 0 || -z "$aespass" ]]; then
echo "Wrong input" >&2
return 2
fi
if [ "e" == "$action" ]; then
read -sp "Please confirm by typing it again: " aespass2
res=$?; echo
if [[ $res -ne 0 || "$aespass" != "$aespass2" ]]; then
echo "Wrong input" >&2
return 3
fi
fi
# for each command-line arg
while [ -n "$1" ]; do
# skip file if unreadable
if [ ! -r "$1" ]; then
echo "Unreadable file: '$1'" >&2
status=$((status|4))
shift; continue
fi
# Append or remove .aes output file extension according to $action
[ "e" == "$action" ] && out="$1.aes" || out="${1%.aes}"
# Encode or decode verbosely
[ "d" == "$action" ] && echo "Decrypting '$1' => '$out'"
echo $aespass | openssl enc -$action -pass stdin -aes-256-cbc -pbkdf2 -iter $iterations -in "$1" -out "$out"
if [ $? -eq 0 ]; then
[ "e" == "$action" ] && echo "File '$1' encrypted with aes-256-cbc pbkdf2 $iterations iterations => '$out'"
[ "d" == "$action" ] && echo "Success"
else
echo "failure with openssl enc -$action" >&2
status=$((status|8))
fi
shift
done
return $status
}