Simple Ruby module for encrypting text with Blowfish

blowfish.rb

require 'openssl'

module Blowfish
  def self.cipher(mode, key, data)
    cipher = OpenSSL::Cipher::Cipher.new('bf-cbc').send(mode)
    cipher.key = Digest::SHA256.digest(key)
    cipher.update(data) << cipher.final
  end

  def self.encrypt(key, data)
    cipher(:encrypt, key, data).unpack('H*').first
  end

  def self.decrypt(key, text)
    cipher(:decrypt, key, [text].pack('H*'))
  end
end

if $0 == __FILE__
  p "text" == Blowfish.decrypt("key", Blowfish.encrypt("key", "text"))
end

Not making use of the initial vector which is part of CBC. IV is stored outside of the data, in plaintext. For your simple demo, add cipher.iv = 'elsewher' after line 6, or new param iv.