Blowfish Encryption using ECB with short keys compatible with http://sladex.org/blowfish.js/ext/blowfish.js

blowfish.rb

require 'openssl'
require 'base64'

class Blowfish
  def initialize(key, algorithm = 'bf-ecb')
    @key = key
    @algorithm = algorithm
  end

  def encrypt(data)
    cipher = OpenSSL::Cipher.new(@algorithm)
    cipher.encrypt
    cipher.key_len = @key.length
    cipher.key = @key

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

    Base64.encode64(binary_data).strip
  end

  def decrypt(data)
    cipher = OpenSSL::Cipher.new(@algorithm)
    cipher.decrypt
    cipher.key_len = @key.length
    cipher.key = @key

    data64 = Base64.decode64(data)
    binary_data = cipher.update(data64)
    binary_data << cipher.final
  end
end

data = 'HelLo_WorlD'

crypto = Blowfish.new('TESTKEY')
encrypted_data = crypto.encrypt(data)
decrypted_data = crypto.decrypt(encrypted_data)

p ['encrypted_data', encrypted_data]
p ['decrypted_data', decrypted_data]
p ['valid?', decrypted_data == data]