Refactoring, RSA Wrapper, and so on.

[merqlove]

• Removed ursa dependency. It still work with ursa by default, need to add few lines about into doc's.
• Created rsa-wrapper via execFile with realtime cleanup.
• Added params for RSA wrapper.
• Auth method now works async.
• Updated tests.

It works on v0.11.x and still fast. Anyway look into.

[mal]

Going to take a look at porting ursa to node 0.11 at the weekend, the API doesn't seem to have changed too much.

[merqlove]

Seems that Ursa needs Nan wrapper for its c++ source methods.

[mal]

So porting the whole of ursa was a bit much in the time allotted, but the bare minimum, at least, was achievable. Using the Nan wrappers, it compiles, runs and returns correct results for the function or two node-chef cares about.

Emailing around yielded a few points of interest; while the ursa library seems to have fallen out of use by it current maintainers, there has been interest expressed in assuming stewardship of it. If that turns out to be the case, keeping that dependency, and letting the new maintainer(s) tackle the compatibility issues seems like the best option. If that doesn't pan out however, the bare minimum can be dropped directly into chef-node to cover our use case.

Personally my preferred option is to wait for 0.12 to drop, and go from there, rather than try to support unstable releases. To that end I'm closing this PR, but will open an issue regarding future support for 0.12.

In the meantime it should be possible to use the initial release (v0.0.1) if you desperately need chef-node running on 0.11, which uses the CLI openssl tool to manage authentication as documented in the Chef docs.

[merqlove]

Ok, but for my own projects, i will use my fork, because i prefer execFile instead of exec. Also in 0.0.1 no check for openssl path). I only made it because of usage in node-webkit project, which have 0.11 dependency.