I would like the client connect to an STS to obtain a SAML token and use it to authenticate it self to a service, but I want the token to contain more information than the standard SAML token, I would also like to avoid using transport level security.
In a sense it will be very similar to a kerberos ticket having the session key
is this possible?
Yes, definetely possible. I’ve seen SAML holder-of-key with symmetric encryption being applied in one place.