Re: [saml-dev] SSO multiple SPs

[Peter Schober <peter.schober@univie.ac.at>]

* Security Developer <security.developer22@gmail.com> [2014-03-14 07:41]:
> How does IDP know that it should not authenticate the user when SAML
> authentication request comes from second SP?

SSO is a function of the IDP establishing a session (via whatever
means) with the subject's HTTP user agent.
So which SP (second, first, any other) doesn't factor into it.
As Paul pointed out, the (any) authentication request can influence
this behaviour, though.
-peter