Starter code to help you solve PlaidCTF compression 250.

compression.rb

#!/usr/bin/env ruby
#
#   $ gem install ronin-support
#   $ python compression.py &
#   $ ruby compression.rb
#
require 'rubygems'
require 'ronin/formatting/binary'
require 'ronin/network/tcp'
require 'hexdump'

include Ronin::Network::TCP

messages = ["hello"]

tcp_session('localhost',4433) do |socket|
  nonce = socket.recv(8)
  puts "Nonce: #{nonce.hex_escape}"

  messages.each do |message|
    socket.send(message.length.pack(:uint),0)
    socket.send(message,0)

    length = socket.recv(4).unpack(:uint).first
    data   = socket.recv(length)

    puts "Ciphertext:"
    data.hexdump
  end
end