Question

I have a model and in that model I’m generating a more complex field than I’ve done before. I’ve serialized hashes and arrays, but this field is the result of Gibberish::RSA.generate_keypair ( https://github.com/mdp/gibberish ). Which is more or less a private/public key pair in a ruby wrapper, to my understanding.

Working from the command line, I can do an update_attributes and the result of the generation gets stored in the text field. When doing rake db:seed or creating an instance, this doesn’t work, I get a yaml string that indicates several types of Gibberish objects.

How do I do more complex activerecord serialization beyond hashes and arrays? Or how do I approach a greater understanding of what I’m trying to do?

Code:

  def generate_keypair
    self.update_attributes(:rsakey => Gibberish::RSA.generate_keypair(1024) )
  end

which I call on the associated model creation, basic call the Gibberish wrapper

Then the output I get for the field myresource.rsakey

"--- !ruby/object:Gibberish::RSA::KeyPair\nkey:
!ruby/object:OpenSSL::PKey::RSA {}\ncipher:
!ruby/object:OpenSSL::Cipher::Cipher {}\n"

Updating the attributes works from the rails command line, but not while seeding or creating. Other ways I attempted to add serialize so far have completely ruined the process or the created instances.

EDIT: solved bluntly by just calling ‘to_s’ on the result of the keypair generation method, which just saves it as a text field that ‘works for now’ until it needs to be more elegant.

Answer 1

The underlying issue seems to be that the openssl library doesn’t implement YAML dumping:

YAML.dump(OpenSSL::PKey::RSA.generate(1024))
#=> "--- !ruby/object:OpenSSL::PKey::RSA {}"

If you are using rails 3.1 you can define custom serializers, like so

class KeySerializer
  def dump(key)
    key.to_pem
  end

  def load(data)
    data && OpenSSL::Pkey::RSA.new(data)
  end
end

Then in your class you can do

class Foo < ActiveRecord::Base
  serialize :key, KeySerializer.new
end