Subject: Re: TSP interop update

From: Margus Freudenthal <[email-masked]>
Date: Fri, 01 Feb 2002 09:59:50 +0200

Peter Gutmann wrote:
> 
> What if the client prefers policy X, but will accept anything if that's not
> available?  This is standard procedure for restaurants, libraries, ...
> 
The client doesn't request some specific policy just for the kicks. He
needs the time stamp for proving something to someone. This someone will
most likely have rules according which he verifies time stamps ("I
expect time stamps to be signed by TSA X and issued under policy Y").
Therefore, receiving time stamp with policy which may or may not be
equal or similar to the one requested, is of little value to the
time-stamping client. In addition, this makes the protocol more complex
as the client must implement procedures for dealing with time stamps
with funny and unexpected policy identifiers.

-- 
Margus

---

From: Denis Pinkas <[email-masked]>
Date: Fri, 01 Feb 2002 09:35:53 +0100

Peter,

> >It is simmple: if a client requests a policy and if the server supports that
> >policy, why should the server choose a different policy ? Just to annoy the
> >client ?
> 
> available?  

Simple.
 
First exchange:  he asks for a given policy and does not get it.
Second exchange: he does not use the optional field reqPolicy and 
                 thus gets what the server has.

Denis 

> This is standard procedure for restaurants, libraries, ...
> 
> Twitchen: "We'll have the duck".
> Fawlty: "Duck's off, sorry".
> Twitchen: "We'll have the trifle then".
> 
> TSP however requires:
> 
> Twitchen: "We'll have the duck".
> Fawlty: "You ponce in here expecting to be waited on hand and foot. Well, I'm
>          trying to run a TSA here. Have you any idea how much there is to do?
>          Go away".
> 
> Ah, we have an RFC which standardises Fawlty Towers.
> 
> Peter.