Enable SSO only on a specific Portal login page

[turchynv]

Hello,

We are running ServiceNow Portal and configured it with SSO. Everything works as designed, however we have a use case where we need to have SSO kick off only on a specific portal page, if it's possible at all.  Or perhaps there is different approach to achieve what we are trying to do.

Here is the use case.

- A kiosk PC that serves clients to request equipment is locked down to run a web browser on start up in KIOSK mode and connects to the Portal's login page /portalname?id=mainlogin. When a client logs in, they fill out the form, click submit and their session gets auto-logged out and redirected to the login page /portalname?id=mainlogin. If SSO is enabled on the portal, it will take over the login page by default and the page is redirected to the custom SSO log in. The issue is that if the SSO log in is inactive for 10 minutes and the client logs in, they are taken to a blank page.

In an attempt to circumvent the issue, I created another page /portalname?id=prelogin with a URL button that redirects to the login page /portalname?id=mainlogin and set it as the homepage on the Portal. However, SSO also kicks in on that "prelogin" page.

Is there a way to tweak SSO or Portal configuration so that SSO triggers only on the /portalname?id=mainlogin page or is there another approach that can be implemented to suit this use case? Keep in mind, that Portal's logout must redirect to the prelogin page.

Thank you in advance.