SAML SSO and VPN

Hi,

 

I'm new to SAML and 
have spent the last week reading OASIS documents and whitepapers from SSO 
companies. I was wondering if anyone knew of a SAML profile or use case for VPN 
with SAML?

 

Is there a way 
for a VPN box to authenticate a user and then pass the authentication 
information to a source site through SAML? Could this be as simple as 
sending a SAML assertion inside a SAML response which is in a HTTP post? Would 
SOAP be needed?

 

Is there a chicken 
and egg problem when adding VPN to SAML SSO? Consider a situation where the 
source site is inside a VPN. How does a user establish a VPN session if his/her 
browser doesn't have access to the source site?

 

I'm using the term 
"source site" as its used in section 4 of the 1.1 version of 
[SAMLBind].

 

thanks

Ed 
Perreault