Lately OAuth is getting pretty popular. Several websites are adopting it as the preferred authentication mechanism for their APIs, and most of them as the only one. So what exactly is OAuth, and what does it do? According to the official website:
This is what OAuth does, it allows the you the User to grant access to your private resources on one site (which is called the Service Provider), to another site (called Consumer, not to be confused with you, the User). While OpenID is all about using a single identity to sign into many sites, OAuth is about giving access to your stuff without sharing your identity at all (or its secret parts).
Basically, OAuth is a way to authenticate to a webservice without having to store the user’s password, and in most cases without even having to ask the user for it. Twitter adopted OAuth for its API, and as of August 16th, it’ll be the only way to use the API. In this post I will explain how to use OAuth to authenticate with Twitter in Cocoa/Objective-C.