Create a course/ xblock secret

[Ethan Keller]

I'm making an xblock that uses an external API to evaluate answers. The API requires a secret key that is used to authenticate the requests. I could either upload the key assigned to a designated user that has viewing access (and can thus validate answers through the API), OR I can have students submit their own API key, so we can validate their answers using their own credentials.  Either way, I will need a mechanism for storing and deploying a secret key in a way that the xblock can reliably consume. With the first approach, this could be somehow setting an environment variable within the studio that gets loaded into the xblock process - or perhaps a file that somehow only my xblock has access to. Is there any such support for an xblock that needs to rely on secret information?