Ryan Boyd - Getting Started with OAuth 2.0

Copyright 2012 Ryan Boyd

OReilly books may be purchased for educational, business, or sales promotional use. Online editions are also available for most titles (.

Nutshell Handbook, the Nutshell Handbook logo, and the OReilly logo are registered trademarks of OReilly Media, Inc. Getting Started with OAuth 2.0 , the image of a horned trunk fish, and related trade dress are trademarks of OReilly Media, Inc.

Many of the designations used by manufacturers and sellers to distinguish their products are claimed as trademarks. Where those designations appear in this book, and OReilly Media, Inc., was aware of a trademark claim, the designations have been printed in caps or initial caps.

While every precaution has been taken in the preparation of this book, the publisher and authors assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein.

Ive been working with web-based APIs since 1999, building SOAP-based web services for internal IT applications and helping thousands of developers using Googles REST-based APIs for Google Calendar, Picasa Web Albums, YouTube, and more. Each of these APIs has required authorization from users to act on their behalf. Developers using these Google APIs were initially required to use proprietary technologies like ClientLogin and AuthSub. If these same developers wanted to integrate with APIs provided by Yahoo!, they needed to use Yahoo!s BBAuth. The use of these proprietary authorization technologies made it challenging to build applications using APIs from multiple providers.

The development of OAuth 1.0 reduced many of the headaches for developers and allowed them to use a single authorization technology across hundreds of APIs on the Web. However, OAuth 1.0 came with some challenges as wellcryptographic signatures and limited definition of how to use it for authorizing applications not using a server-to-server web application flow. Im delighted that the standardization of OAuth 2.0 is nearly complete, as it provides an authorization protocol thats easy to use both for these types of applications and for a variety of other use cases.

Perhaps most exciting is the upcoming standardization of OpenID Connecta protocol built on top of OAuth 2.0 to enable using the same identity to log in (authenticate) to multiple applications. While Ive worked with hundreds of developers who have successfully built earlier versions of OpenID authentication into their web applications, its rarely been a very smooth process. Just as OAuth 2.0 makes authorization easier for developers, OpenID Connect does the same for authentication.

I hope this book gives you the foundation knowledge you need to work with OAuth 2.0 and OpenID Connect as the next-generation authorization and authentication technologies for the Web.