OAuth 2.0 Concepts
Internal
Overview
According to RFC 6749 - The OAuth 2.0 Authorization Framework, OAuth 2.0 is an authorization framework that enables a third-party application to obtain limited access to an HTTP service, either on behalf of a resource owner by orchestrating an approval interaction between the resource owner and the HTTP service, or by allowing the third-party application to obtain access on its own behalf.
OAuth2 Primitives
Resource Owner
Protected Resource
Client
Authorization Server
OAuth2 Access Token
OAuth2 Grant Types
There are four OAuth2 grant types:
- Authorization Code Grant Type
- second
- third
- fourth
Authorization Code Grant Type
To Process
Identity. Identity Management.
Identity Federation and Single Sign-On are related concepts.
Single Sign-On (SSO) systems allow a single user authentication process across multiple IT systems and organizations. SSO is a subset of federated identity management, as it relates only to authentication and technical interoperability.
User's presence in the system - means that the user identity is associated with the thread that is processing the user's request, and in a way, it is the user that "drives" the thread. The identity is associated with the thread in the form of a security context.
There are software agents that perform actions on behalf of the user, and this is where OAuth is relevant - a user can delegate in a standard and secure way the authority of performing certain actions. Even the software agent (the OAuth client) operates under a different identity, it can still perform action on behalf of a user that may not be even logged in anymore. An example of such identity is an OpenShift service account.
Authentication. The whole point of an authentication protocol is to tell whether the user is present in the system.
Identity Provider (IdP) and Relying Party (RP).
Authentication protocols, single sign-on, SAML.
Authorization.