SAML 2.0 & Authentication mechanism [service]

SAML 2.0 defines a ECP profile which is an 
extension to LECP of ID-FF because ECP talks about PAOS Binding (taken from 
ID-WSF specification) in the profile and thus

makes the specification of this profile more 
complete & concrete.

 

My concern/question is that SAML 2.0 does not 
talk about how authentication should be done 
using standard protocol messages (something like that of ID-WSF Authentication 
Service SASL messages).

For eg. in ECP profile.

ECP ---> SP [ Send HTTP Request ]

SP ---> ECP [Send AuthnRequest using PAOS 
binding]

 

                
Authentication

ECP    
<-------------------------->   IDP   

 

Messages for the above step are problems for me. I 
know I can use Authentication service for this as defined in ID-WSF 
(SASL) but somehow not feeling comfortable mixing specifications in 
implementation.

 

Plase advise me for this concern of 
mine.

 

Kapil Sachdeva
http://www.dotnetcard.com/blogs/ksachdeva