Re: Sub/Not Security, Presence service identifiers
[email protected] (John D. Ramsdell)
| Newsgroups | gmane.ietf.impp |
|---|---|
| Message-ID | <[email protected]> |
"Peterson, Jon" <[email protected]> writes: > Actually, I'm not sure this is true. The presence information could be > signed by the presentity. If so, it's irrelevant how the signed presence > information is transported to the watcher, provided it is > transported intact I completely disagree with this analysis. Let's look at the requirement. 5.2.4 of RFC2779 says The protocol MUST provide means of protecting B from another PRINCIPAL C "spoofing" notification messages about B. The requirement is about giving B the means to distinguish between notification messages sent by authoritative sources from those sent by non-authoritative sources. The path by which the presence information is relevant. In particular, a bad guy can take perfectly good presence information, and spoof B by delaying and/or changing the order of delivery of presence information. Jon, I updated my example on the need for presence service identifiers and set it to the list. See if that helps you decide who must sign presence notifications. John [reminder: [email protected] for non-technical discussions, please]