Return an Idemix Enrollment as a Serialized String

[KarthikKavinA]

Added an API to return an Identity Mixer Enrollment as a Serialized
String

Signed-off-by: Kavin a.kavin24@gmail.com

[bestbeforetoday]

There is not enough implementation here to really know where you are going with this longer term, and no testing.

I think what you're trying to achieve is to be able to convert the Idemix enrollment into some serialized form that you can later deserialize to recreate an Idemix enrollment. I'm not sure if the IdemixEnrollmentSerialized class is really necessary or even helpful for that. A meaningful change really needs to provide the whole round-trip from object to serialized form and back again, along with unit tests.

If that round-tripping really is the objective, possibly it would make more sense to have a serialize method on the IdemixEnrollment that returns some serialized form of the content (which could be something standard like JSON but doesn't need to be specified since the end user isn't intended to parse it), and a factory function to allow an IdemixEnrollment to be recreated from that serialized form? Taking that approach, I would encourage you to include a version number in the serialized data to indicate the serialized format version. If it ever needs to change in the future you can increment the version number, and include logic in the deserialization code to handle both formats.

[bestbeforetoday]

It's not returning an Idemix enrollment as a serialized string. It's returning an Enrollment interface, which provides only these methods:

public interface Enrollment {
    PrivateKey getKey();
    String getCert();
}

In the returned implementation, both of those methods return null so it is not a useful return value.

[bestbeforetoday]

This pull request has been open for a long time without any updates to move it towards a successful change, so I am closing.