Subject: RE: [Simple] immediate notify issue

From: "Christian Huitema" <[email-masked]>
Date: Tue, 27 Feb 2001 08:59:50 -0800

> However, there is now a problem with the notify. A client 
> could determine whether the PUA was online, or whether its 
> subscription was accepted, based on when a NOTIFY arrives (a 
> slightly delayed one indicates they are online and authorized 
> the subscription; one that never arrives likely means they 
> are offline or the subscription was rejected).

Uh, why is this a problem, exactly? The privacy property we aimed for
was that there is no difference between "being offline" and "rejecting
the subscription." Arguably, we have achieved that with the decoupling
of subscribe and notify. There is indeed a way to build up more
byzantine protections, e.g. providing partial information to some
parties, even providing false information when you really want to hide.
But you don't want to modify the protocol to achieve that -- it looks to
me as an implementation choice. Come to think of it, a protocol
modification would be somewhat comical; think of a Notify parameter that
mentions that "how, by the way, the information in the message may or
may not be true..."

-- Christian Huitema

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From: James Undery <[email-masked]>
Date: Tue, 27 Feb 2001 17:46:53 +0000

Christian Huitema wrote:

> the subscription."

Well there is a difference, a notify is required immediately by the CPIM
draft if the subscribe is successful, a 202 I'd consider success of a kind.
If you consider the three cases

1 I subscribe get a 202 and no notify for the presentity
2 I subscribe get a 202 and a notify that they are offline
3 I subscribe get a 202 and a notify that they are online

case 3 my subscription was accepted.
case 2 my subscription may not be accepted but I know the presentity is
offline.
case 1 my subscription was rejected and I know the presentity is online.

In both cases the presentity did not want me to have presence info I know
its presence state. Jonathan's suggestion fixes this so "being offline" and
being rejected are identical as cases 1 and 2 become identical.

James Undery

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From: Rohan Mahy <[email-masked]>
Date: Tue, 27 Feb 2001 10:23:11 -0800

If I don't care about this property, is it still legal for me to configure 
my client to 403 the SUBSCRIBE?  (say my client will only accept subscribes 
from folks that have ever sent me a message or invite)

thanks,
-rohan

At 09:46 AM 2/27/01, James Undery wrote:

>_______________________________________________
>simple mailing list
>[email-masked]
>http://mailman.dynamicsoft.com/mailman/listinfo/simple

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From: "Krishna (External)" <[email-masked]>
Date: Wed, 28 Feb 2001 21:16:40 -0800

----- Original Message -----
From: Christian Huitema <[email-masked]>
To: Jonathan Rosenberg <[email-masked]>;
<[email-masked]>
Sent: Tuesday, February 27, 2001 8:59 AM
Subject: RE: [Simple] immediate notify issue