Using OpenSSL with Ruby to do AES encryption

aes_crypt.rb

# This module for using AES encryption with ruby from
# http://www.brentsowers.com/2007/12/aes-encryption-and-decryption-in-ruby.html

require 'openssl'
require "base64"
module AESCrypt
  # Decrypts a block of data (encrypted_data) given an encryption key
  # and an initialization vector (iv).  Keys, iv's, and the data 
  # returned are all binary strings.  Cipher_type should be
  # "AES-256-CBC", "AES-256-ECB", or any of the cipher types
  # supported by OpenSSL.  Pass nil for the iv if the encryption type
  # doesn't use iv's (like ECB).
  #:return: => String
  #:arg: encrypted_data => String 
  #:arg: key => String
  #:arg: iv => String
  #:arg: cipher_type => String
  def AESCrypt.decrypt(encrypted_data, key, iv, cipher_type)
    aes = OpenSSL::Cipher::Cipher.new(cipher_type)
    aes.decrypt
    aes.key = key
    aes.iv = iv if iv != nil
    aes.update(encrypted_data) + aes.final  
  end
  
  # Encrypts a block of data given an encryption key and an 
  # initialization vector (iv).  Keys, iv's, and the data returned 
  # are all binary strings.  Cipher_type should be "AES-256-CBC",
  # "AES-256-ECB", or any of the cipher types supported by OpenSSL.  
  # Pass nil for the iv if the encryption type doesn't use iv's (like
  # ECB).
  #:return: => String
  #:arg: data => String 
  #:arg: key => String
  #:arg: iv => String
  #:arg: cipher_type => String  
  def AESCrypt.encrypt(data, key, iv, cipher_type)
    aes = OpenSSL::Cipher::Cipher.new(cipher_type)
    aes.encrypt
    aes.key = key
    aes.iv = iv if iv != nil
    aes.update(data) + aes.final      
  end
end



# Here is an example of using the module above with the
# test vectors from http://www.inconteam.com/software-development/41-encryption/55-aes-test-vectors


puts "TEST VECTOR "
key = "603deb1015ca71be2b73aef0857d77811f352c073b6108d72d9810a30914dff4"
test_vector = "6bc1bee22e409f96e93d7e117393172a"
puts "Key length #{key.length} (#{key})"
puts "Test Vector: #{test_vector}"
binary_test_vector = test_vector.unpack('a2'*32).map{|x| x.hex}.pack('c'*32)


binary_key = key.unpack('a2'*32).map{|x| x.hex}.pack('c'*32)


x  = AESCrypt.encrypt(binary_test_vector, binary_key,  nil, "AES-256-ECB")

e = x.unpack("C" * 32).map{|x| sprintf("%02x", x)}.pack('A2'*32)
puts e.inspect