The NetTuts.com site has a new tutorial posted showing you how to work with the authentication of the WordPress REST API and using its OAuth 1.0a handling. This is part three in their series of tutorials introducing the WordPress REST API.
In the previous part of the series, we set up basic HTTP authentication on the server by installing the plugin available on GitHub by the WP REST API team. [...] For using authentication on production servers, there needs to be a more secure way of sending authenticated requests without risking exposing the login credentials. Thanks to the OAuth authentication method, those requests can be sent without exposing the username and the password in an unsafe manner.
In the current part of the series, we will learn to set up and use the OAuth authentication method to be used with the WP REST API plugin.
They start the tutorial with a brief look at what OAuth is and how it's used to authenticate the end user/client/software/etc. They then walk through the flow of a simple OAuth-based authentication system and the pieces that make it up. Then the article gets into how to install the plugin for your WordPress instance and activate it from the command line. They show how to test that it's enabled and how to use a command line client to create tokens you can then use to access the API in your own clients.