def find_cipher(*args)
      fail ArgumentError, 'Unknown algorithm ' + algorithm unless args[0] == 'http://www.w3.org/2001/04/xmlenc#aes256-cbc'

      cipher = ::OpenSSL::Cipher.new('AES-256-CBC')
      cipher.decrypt
      cipher.padding = 0
      cipher.key     = find_cipher_key(cipher, *args[1..4])
      cipher.iv      = args[5]

      cipher
    end
def find_cipher(*args)
      fail ArgumentError, 'Unknown algorithm ' + algorithm unless args[0] == 'http://www.w3.org/2001/04/xmlenc#aes256-cbc'

      cipher = ::OpenSSL::Cipher.new('AES-256-CBC')
      cipher.decrypt
      cipher.padding = 0
      cipher.key     = find_cipher_key(cipher, *args[1..4])
      cipher.iv      = args[5]

      cipher
    end
Create a cipher based on an ODS algorithm URI from manifest.xml
 params: algorithm, key_derivation_name, hashed_password, salt, iteration_count, iv