gistfile1.rb

# Results:

# +------------+--------------+------------+
# | Type       | Uncompressed | Compressed |
# +------------+--------------+------------+
# | Plaintext  | 649779       | 251901     |
# | Ciphertext | 649792       | 625780     |
# +------------+--------------+------------+

require 'openssl'
require 'zlib'
require 'terminal-table'

def gzip(string)
  wio = StringIO.new("w")
  w_gz = Zlib::GzipWriter.new(wio)
  w_gz.write(string)
  w_gz.close
  wio.string
end

aes = OpenSSL::Cipher::Cipher.new("AES-256-CBC")
aes.encrypt
aes.random_key
aes.random_iv

plaintext = File.read('WutheringHeights.txt')
ciphertext = aes.update(plaintext)
ciphertext << aes.final

table = Terminal::Table.new(
  headings: ['Type', 'Uncompressed', 'Compressed'],
  rows: [
    ['Plaintext', plaintext.length, gzip(plaintext).length],
    ['Ciphertext', ciphertext.length, gzip(ciphertext).length]
  ]
)

puts table