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This tutorial goes through a SSO setup process. This is intended for developers and administrators configuring external websites where they want users who are logged in at one site, to go to another site, and be visible already logged in without the need to click a “sign in” link at all. All such sites must already support normal OpenID Connect login process.
Pre-requirements
You have multiple websites which already use normal OpenID Connect authorisation process to allow user sign-in.
Goal
You want to avoid users needing to click “sign in” when they arrive at a new site.
User goes to site 1.
User logs in at site 1.
User goes to site 2 for the first time.
User appears to already be signed in at site 2 without the need to interact with the UI.
How this works
The goal is made possible by having the user’s browser make a request to site 2 during site 1’s authorisation process. During this request site 2 receives a token which it can use later to have the user sign in without interaction. Site 2 should set a cookie to the browser, which it will read later when the user arrives at site 2 for the first time. When this happens, site 2 redirects the user to the OpenID Connect authorisation URL with the token parameter included. If the token is valid, the user will authorise site 2 and is redirected back without interaction.
Step 1: Create a SSO callback endpoint
Each site which wants to participate in this SSO scheme needs an endpoint which receives the token, adds browser cookies, and possibly returns an icon for display during authorisation.
The endpoint should be in the same domain as the site and other authorisation callbacks.
The endpoint should:
Invalidate any existing user session (as this is a new sign-in, possibly by a different user)
Read added query parameters from the call
sso-token- The SSO tokensso-validity- Token validity time in minutes from time of request, after which the token is invalid.
Store the received information. Add cookies to the browser from the site’s own domain. The cookies should contain enough information to be able to use the above information later.
Optionally return a small logo image file in response, as this request came from an
<img src=”callback-url” />element.
Step 2: Provide the callback URL
Go to the site’s client’s information in TIS, find the field “Single Sign-On Callback URL” and enter the callback endpoint’s URL here.
Step 3: Add a “Single Sign-On Target”
TODO: What exactly is the purpose of the “Target”, what breaks if it does not exist.
In TIS management go to the “Single Sign-on” view.
Every site has a different OpenID Connect client registered. For each site:
Click “Add”. Select “OpenID Connect” as the mechanism.
Select the OpenID Connect client of the site.
Configure other details if needed.
Save the new Target.