Re: [mile] Ben Campbell's Discuss on draft-ietf-mile-xmpp-grid-09: (with DISCUSS and COMMENT)

[Florian Schmaus <[e-mail]>]

On 25.03.19 14:52, Peter Saint-Andre wrote:
> I propose adding a new subsection under "Countermeasures":
> 
> 8.3.6.  End-to-End Encryption of Messages
> 
>    Because it is expected that there will be a relatively large number
>    of Consumers for every Topic, for purposes of content discovery and
>    scaling this document specifies a "one-to-many" communications
>    pattern using the XMPP Publish-Subscribe extension.  Unfortunately,
>    there is no standardized technology for end-to-end encryption of one-
>    to-many messages in XMPP.  This implies that messages can be subject
>    to eavesdropping, data injection, and data modification attacks
>    within a Broker or Controller.  If it is necessary to mitigate
>    against such attacks, implementers would need to select a messaging
>    pattern other than [XEP-0060], most likely the basic "instant
>    messaging" pattern specified in [RFC6121] with a suitable XMPP
>    extension for end-to-end encryption (such as [RFC3923] or a more
>    modern method such as [XEP-0384]).  The description of such an
>    approach is out of scope for this document.

I'd like to point out that XEP-0384 can sadly, in its current state, not
be used for this, as it only allows encryption of the <body/> element
content. But there is the series of "OpenPGP for XMPP" XEPs (XEP-0373,
-0374), which do support the encryption of arbitrary extension elements
and hence is suitable for this use case. Full disclaimer: I am one of
the authors of those XEPs and therefore should be considered biased.

- Florian