Brute force steganography passwords

StegBrute.rb

#!/bin/env ruby
# Hispgatos
# by ReK2, Fernandez Chris
# https://keybase.io/cfernandez
# Bruteforce password protected documents hidden inside images
# add you dictionary below to the dic variable
# of course you need to have installed steghide

require 'open3'


if ARGV.size > 1
  puts "to many arguments, enter just one image file name"
  exit
elsif ARGV.size == 0
  puts "you need to add one image file as argument"
  exit
end

image = ARGV[0]
dic = "rockyou.txt"
puts "about to bruteforce image: #{image}"

File.readlines("#{dic}").each do |line|
  stdout_str, error_str, status = Open3.capture3("steghide extract -sf #{image} -p #{line}")
  unless ! status.success?
      puts "encontrado password: #{line}"
      exit
  else
      #esto si se quiere ver el resultado
    print "."
  end
end