aes_256_cbc.rb

#!/usr/bin/env ruby
# -*- coding: utf-8 -*-

require 'base64'
require 'digest'
require 'openssl'

def encode(cryptkey, iv, cleardata)
  cipher = OpenSSL::Cipher.new('AES-256-CBC')
  cipher.encrypt  # set cipher to be encryption mode
  cipher.key = cryptkey
  cipher.iv  = iv

  encrypted = ''
  encrypted << cipher.update(cleardata)
  encrypted << cipher.final
  encrypted
end

def b64enc(data)
  Base64.encode64(data).gsub(/\n/, '')
end

cryptkey = Digest::SHA256.digest('Nixnogen')
iv       = 'a2xhcgAAAAAAAAAA'
buf      = "Here is some data for the coding" # 32 chars
enc      = encode(cryptkey, iv, buf)

puts "Encoded length: #{enc.length}"
puts "Encoded in Base64: " + b64enc(enc)