#!/bin/sh
# GPG Encrypted Letters - Oldschool meets Newschool
# GPG encrypt your message and put it into a QRCode
# This QRCode will be sent to your printer
# Now send this letter to it's destination
# To decrypt you have to scan the letter
# And this script will decrypt it for you.
#
# Presented by myself at the #1 Cryptoparty in Luxembourg
# 
# Coded by Perforin/virii - cypherpunk.lu - c3l.lu

receiver=$2

if [ "$1" = "-e" ]; then
# encrypting message

echo "[+] Type your message"
echo "[!] Press CTRL+D when done"

gpg -e -a -r $receiver -o qr-message.tmp

cat qr-message.tmp | qrencode -o encrypted-QRcode.png
rm qr-message.tmp

echo "[+] Sending to printer..."

lp -n 1 encrypted-QRcode.png
rm encrypted-QRcode.png

echo "[+] Done!"
echo "[!] You can now send this QRcode to your friend"

elif [ "$1" = "-d" ]; then
# decrypting message
# you need zbarimg version 0.10! Currently NOT in the repos
# Build from source http://zbar.sourceforge.net/download.html

echo "[+] Scanning..."

scanimage -p --format=tiff --resolution=200 > scanned_QRcode.tiff

echo "[+] Decoding..."
echo "[+] Press CTRL+D if cleartext is not shown"

zbarimg --raw scanned_QRcode.tiff | gpg -d
rm scanned_QRcode.tiff

else
	echo "GPG QRcode Maker/Reader"
	echo "by virii - C3L.lu\n"
	echo "Usage: $0 [options] [receiver]"
	echo "Encryption: $0 -e <KEYID>"
	echo "Decryption: $0 -d\n"
fi