ruby/openssl

decrypt.rb

require "openssl"
require "base64"

@algorithm = "AES-256-CBC"

def main(encrypted_data_file, secret_key, decrypted_data_file)
  print "Reading encrypted data file... "

  encrypted_data = File.open(encrypted_data_file, "r") do |file|
    file.read().unpack("m")[0]
  end

  puts "done."
  print "Reading secret key file... "

  key = File.open(secret_key, "r") do |file|
    file.read().unpack("m")[0]
  end

  puts "done."
  print "Setting up cipher... "

  iv = OpenSSL::Cipher::Cipher.new(@algorithm).random_iv
  cipher = OpenSSL::Cipher::Cipher.new(@algorithm)
  cipher.decrypt
  cipher.key = key
  cipher.iv = iv

  puts "done."
  print "Decrypting data... "

  decrypted_data =  cipher.update(encrypted_data)
  decrypted_data << cipher.final

  puts "done."
  print "Writing decrypted data to file... "

  File.open(decrypted_data_file, "w") do |file|
    file.write decrypted_data
  end

  puts "done."
end

abort "usage: decrypt.rb <encrypted-data-file> <secret-key> <decrypted-data-file>" if ARGV.size < 3

main ARGV[0], ARGV[1], ARGV[2]

encrypt.rb

require "openssl"
require "base64"

@algorithm = "AES-256-CBC"

def main(data_file, secret_key, encrypted_data_file)
  print "Reading data file... "

  data = File.open(data_file, "r") do |file|
    file.read()
  end

  puts "done."
  print "Reading secret key file... "

  key = File.open(secret_key, "r") do |file|
    file.read().unpack("m")[0]
  end

  puts "done."
  print "Setting up cipher... "

  iv = OpenSSL::Cipher::Cipher.new(@algorithm).random_iv
  cipher = OpenSSL::Cipher::Cipher.new(@algorithm)
  cipher.encrypt
  cipher.key = key
  cipher.iv = iv

  puts "done."
  print "Encrypting data... "

  encrypted_data =  cipher.update(data)
  encrypted_data << cipher.final

  puts "done."
  print "Writing encrypted data to file... "

  File.open(encrypted_data_file, "w") do |file|
    file.write [encrypted_data].pack("m")
  end

  puts "done."
end

abort "usage: encrypt.rb <data-file> <secret-key> <encrypted-data-file>" if ARGV.size < 3

main ARGV[0], ARGV[1], ARGV[2]

key.rb

require "openssl"
require "base64"

@algorithm = "AES-256-CBC"

def main(secret_file)
  print "Generating new key... "

  key = OpenSSL::Cipher::Cipher.new(@algorithm).random_key

  puts "done."
  print "Writing key to file '#{secret_file}'... "

  File.open(secret_file, "w") do |file|
    file.write [key].pack("m")
  end

  puts "done."
end

abort "usage: key.rb <secret-file>" if ARGV.size < 1

main ARGV[0]