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Use Cases

Browser Single Sign-On (B-SS0)#

Web browser SSO is one of the main use cases for Janssen. The OpenID Connect interfaces of the Auth Server provide the identity layer that manages authentication and B-SSO. Auth Server tracks web browser sessions via a cookie. An end user may actually have several active sessions, although only one session is active. For example, below is a hypothetical session cookie:

session_id: c691e83d-eb1b-41f0-b453-fab905681b5b
current_sessions: ["de510ab6-b06c-4393-86d8-12a7c501aafe", "c691e83d-eb1b-41f0-b453-fab905681b5b"]

To switch sessions, an RP can redirect to the Jans Auth Server OpenID Connect Provider authorization endpoint with the parameters prompt=select_account.

Native Single Sign-On (N-SS0)#

On most mobile platforms, mobile apps signed by the same vendor certs can share information via the system "keychain" (Account Manager on Android). OpenID Mobile SSO specifies a new scope, extends the token endpoint, and profiles the OAuth2 Token Exchange spec allowing mobile apps to share identity between apps produced and signed by the same vendor (i.e. signed with the same vendor certificate).

Single Logout (SLO)#

The bane of identity engineers everywhere, Auth Server does offer some endpoints that enable SLO. Janssen Auth Server implements Back-Channel Logout and Session Management. But the most commonly used strategy is Front-Channel Logout. This works by displaying a web page with numerous iFrames, each with the respective logout URL for each application. The reason SLO is so hard is that logout is inherently an asynchronous use case. When you need a bunch of websites to receive a notification, some of those notifications may fail. Ideally, you'd replay messages that aren't received. But end users want a fast logout response, and don't want to wait for all the applications to confirm they received and acted on the notification. So making logout synchronous is a round-hole / square-peg situation. But with that said, Auth Server supports it.

API Access Management#

Janssen Auth Server is frequently used to issue access tokens to authenticate software clients that needs to call an API. The OAuth WG has published many useful specifications about how to do this securely, and Janssen implements many of these RFCs and drafts. In OAuth parlance, Jans Auth Server is the Authorization Server; and Jans Client API is a service that helps clients with advanced features like MTLS and private key authentication. As OAuth scopes are frequently used to control the extent of access of clients, many domains are using Jans Auth Server to dynamically render scopes based on the identity of the client, or the security context. The Jans Auth Server also implements OAuth and OpenID client registration API. Finally, Jans Auth Server publishes an SSA endpoint, for OAuth software statement assertions which enables trusted services to request an SSA that specifies what type of clients can register. All of these features mean that Jans Auth Server is an essential tool as part of your API access management infrastructure.

Multifactor Authentication#

OpenID Connect is a web identity layer. Auth Server displays and processes a series of web pages to authenticate a person, and then shares user claims with the applications that requested them. Out of the box, Auth Server supports many MFA workflows, including FIDO, passkeys, OATH OTP (HOTP, TOTP), SMS (via Twilio or SMPP), and many more. But you're not limited to the MFA that comes out of the box. Using Person Authentication Scripts, you can implement any authentication workflow which you can imagine. You can also use the Janssen Project's Agama programming language to implement multi-step authentication workflows.

Mobile Authentication#

One of the initial requirements for OpenID was to support mobile apps (because SAML is terrible for mobile apps). OpenID and OAuth have developed several mitigations that make mobile authentication more secure, which are described in RFC 8252. However, due to the complexity of cookie sharing between the mobile phone browser SDK, and the mobile browser (assuming you are using the system browser), your results may vary if you actually want SSO. Recently, OpenID has published a new specification draft for Native SSO for Mobile Apps, which is on the roadmap. There are some other hacky ways you can implement mobile authentication, for example, using the OAuth password grant--but this is possible only for first-party applications, and is generally discouraged, because there is no way to securely store a client secret in the mobile application, which hackers can easily decompile.

Open Banking#

You'll notice that the Gluu Open Banking Identity Platform is certified for Financial-grade API (FAPI) 1.0 Final--this is Gluu's distribution of the Janssen Auth Server profiled for banking. If you want to implement an OP for open banking, Jans Auth Server is one of the few comprehensive open-source platforms that will enable you to do so.

Social Sign-in#

This could really be covered under the MFA section. But it's not uncommon that as part of an authentication workflow, Auth Server may redirect you to an external identity provider, which then sends you back to Auth Server with some kind of reference id or assertion. Out of the box, Jans supports the top three social sites: Google, Apple, and Facebook (which account for 80% of social login). But of course, you can implement any social login using an Agama project.


It's not that uncommon that an authentication workflow is used to create an account for a person in an identity provider. In fact, it's so common, that the OpenID working group recently created a spec to standardize a parameter in the authentication request to signal to the OpenID Provider that this is what's happening: prompt=create. As we're just displaying a series of web pages, we can display a registration form, process the form (with some kind of remote identity proofing?), send an email, SMS, Telegram messages, or whatever. Also, frequently social login is tied to registration--the first time you login with an external IDP, Auth Server creates an account on the fly with the user claims sent by the remote IDP.


Frequently people conflate the identity layer with the authorization layer. RBAC is still an important security paradigm. So it makes sense to people that the place where you store information about a person's roles is where you define policies about what resources a role can access (i.e. policies). Recently, centralized authorization has had an active resurgence. Companies like Styra, Oso, and HashiCorp have introduced innovative centralized authorization software. These systems, acting as a "policy decision point", enable you to define policies, and can evaluate these policies at runtime. Note: they rely on "policy enforcement points" to call their endpoints, supplying the data which is input to policies. With that said, there are places in Auth Server where you can define or impact authorization (besides user claims). In particular, OAuth scopes are used to convey the extent of access in an access token, that when presented to an API by a software client, enables access control. However, the scope is still input to policy, and may in fact be just one more piece of data considered by a policy decision point. And one more caveat... the "authorization" in an OAuth "authorization server", was originally meant to convey the authorization of the person who was trying to access something. Whether a person consented to share information, or grant a client the ability to act on their behalf, is another important consideration. So does "Auth Server" provide authorization? It depends!

Through the "front channel" (i.e. the browser), Auth Server can interact with a person by displaying web pages. OpenID Connect and OAuth scopes trigger the authorization phase (after authentication). By default, the scopes requested by the client and their respective descriptions are displayed for approval. However, like all pages in Auth Server, these pages can be customized to meet your exact requirements.

Auth Server also implements the User Managed Access Protocol ("UMA"). This profile of OAuth2 enables consent to be sought from a person even after the initial authentication has taken place. This phase is also called "claims gathering", but one of the claims could be whether a person consents to something.

Note: Authorizations are stored relative to a person's entity in the database. How a person views and revokes consent is outside the scope of Auth Server. To view a person's consents, you need to use the config API, as this information is not shared via OpenID Connect or SCIM.

Last update: 2023-10-18
Created: 2022-07-21