[Standards] hash agility in file transfer
dave at cridland.net
Thu Jun 16 08:31:52 UTC 2011
On Thu Jun 16 09:14:41 2011, Remko Tronçon wrote:
> > They're lowercase.
> > The usual way that IANA names differ from other names is that
> IANA always
> > hash the hyphen in SHA names
> Ok then, even better :)
> One drawback of approach 2 and the agreement that all iana hash
> are ok as elements is the potential clash between hash names and
> element names in the namespace of the protocol using the hashes.
> unlikely that Jingle will ever have an element 'sha-1', but still,
> theoretically ...
Hmmm... No. In the protocol, you can use a unified syntax, but in
features you wouldn't. You'd add a hashing feature, and append the
IANA names to that URI, perhaps using fragments (if they're legal in
So Jingle FT would still use:
<hash xmlns='urn:xmpp:crypto:hash' hash='sha-1'/>
(Presumably with the hash value somewhere)
There is a risk that IANA might register a hash name which is not a
legal XML element, but the above copes with this.
I vaguely wonder whether we could use dynamically created namespaces
and/or elements, but that seems to serve little purpose except to
(I'd personally enjoy the notion of a programmatically generated
schema by processing an XSLT over the XML form of the IANA registry,
but I can see the XML purists coming after me with troches and
Dave Cridland - mailto:dave at cridland.net - xmpp:dwd at dave.cridland.net
Infotrope Polymer - ACAP, IMAP, ESMTP, and Lemonade
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