#!/usr/bin/perl
use strict;
use warnings;
use Crypt::Rijndael;
use Crypt::CBC;
my $my_key = $ARGV[0];
my $plainfile="test2.txt";
my $cipher;
my $buffer;
my $decrypted="$plainfile.cry.txt";

# this sub makes all keysize of 32 bytes, in case the key you give is
# smaller. However, remember to use a strong key !!!
sub get32 {
        my $data = shift;
        return "\0" x ( 32 - length($data)%32 ) . $data;
 }

#--------------------------------------------------------------------
# Parameters
#--------------------------------------------------------------------
$cipher = Crypt::CBC->new( {'key'               => get32($my_key),
                              'cipher'          => 'Rijndael',
                              'iv'              => '§%(Ml7!B',
                              'regenerate_key'  => 1,
                              'padding'         => 'standard',
                              'prepend_iv'      => 0
                           });

#--------------------------------------------------------------------
# Encryption
#-------------------------------------------------------------------- 
open(FH_plain,"./$plainfile");
open(FH_crypted, ">$plainfile.cry");
while (read(FH_plain,$buffer,1024)) {
      print FH_crypted $cipher->encrypt($buffer);
  }

close FH_plain;
close FH_crypted;

#--------------------------------------------------------------------
# Decryption
#--------------------------------------------------------------------

open(FH_crypted, "<$plainfile.cry");
open(FH_decrypted, ">$decrypted");
while (read(FH_crypted,$buffer,1024)) {
      print FH_decrypted $cipher->decrypt($buffer); 
  }
close FH_crypted;
close FH_decrypted;