More complex ActiveRecord object serialization - ruby-on-rails

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