Last Call Review of draft-ietf-xmpp-3921bis-

Request Review of draft-ietf-xmpp-3921bis
Requested rev. no specific revision (document currently at 20)
Type Last Call Review
Team Security Area Directorate (secdir)
Deadline 2010-10-21
Requested 2010-10-07
Authors Peter Saint-Andre
Draft last updated 2010-10-29
Completed reviews Secdir Last Call review of -?? by Richard Barnes
Assignment Reviewer Richard Barnes
State Completed
Review review-ietf-xmpp-3921bis-secdir-lc-barnes-2010-10-29
Review completed: 2010-10-29


I have reviewed this document as part of the security directorate's 

ongoing effort to review all IETF documents being processed by the IESG. 

 These comments were written primarily for the benefit of the security 

area directors.  Document editors and WG chairs should treat these 

comments just like any other last call comments.

This document describes an instant-messaging and presence system based 

on the core system of exchanging XML stanzas described in RFC 3920 and 

draft-ietf-xmpp-3920bis.  As the document rightly notes, the underlying 

transport protocol addresses most of the security considerations for 

this document, and that document seems to have a thorough discussion of 

security considerations (although I have not done a thorough review). In 

general, I think that the security considerations in this document 

adequately describe the additional risks posed by the instant-messaging- 

and presence-specific parts of the protocol (beyond those of the base 

protocol), and corresponding mitigations.

One thing that might merit clarification: The overriding 

application-layer security concern here is the proper routing of 

presence and instant messaging stanzas through the XMPP system. 

(Underlying communications security concerns are addressed by the core 

spec.)  For the most part, these concerns with requirements on servers 

to act in certain ways on behalf of the user.  It could be helpful to 

the reader to re-state some of the communications patterns from Section 

13.1 of draft-ietf-xmpp-3920bis and comment on the particular roles that 

the entities play in the context of instant messaging and presence 

(e.g., routing unicast <message> stanzas, fan-out of broadcast presence