I'll try to make this as succinct as possible.
I'm a newer developer for a small company that was hired to modify a Sitefinity site to handle a 3rd party SSO for the members on the site (not the Backend). My company does not host the site, but we are hosting other sitefinity sites. (Which is why we were hired...)
I've read the documentation, but its not making sense.
I'm assuming that we'll modify the current login page (that is simply using the Login widget) to redirect to the SSO Login page with a landing page url, and once someone has successfully logged in, they will be redirected to the given landing page, along with an authorization token.
My question/concern is how do I get Sitefinity to recognize this Authorization token??
I assume you're referring to adding an authentication provider in the Settings > Advanced section. If so, then Sitefinity has a built-in resource of handling the callback your authentication provider generates after a successful sign-in with the identity provider. So the flow looks something like this:
Of course, there's always a lot of gotchas to consider when a platform like Sitefinity simplifies an otherwise complicated process.