On Wed, Sep 12, 2007 at 01:53:37PM +0100, Ian Paterson wrote: > Peter Saint-Andre wrote: > >Ian Paterson wrote: > > > >>In real life servers will always be compromised (especially in cases > >>where the attacker is the service provider). So SASL PLAIN still > >>contains a serious vulnerability that is easily fixed in those cases > >>where DIGEST-MD5 is a practical option. > >> > > > >Except that DIGEST-MD5 is effectively being deprecated by the IETF. Thus > >the interest in SCRAM, YAP, and their ilk. > > > > With all due respect to the experts at the IETF, I feel (as a > non-expert) that they are trying to depricate DIGEST-MD5 before it has a > suitable replacement (i.e. another one that protects users' passwords > from a compromised server). I strongly agree we should recommend/require > SCRAM and/or YAP as soon as they are baked. But is that likely to happen > before 3920bis is puiblished? > > I agree that if we start recommending SASL PLAIN in addition to > DIGEST-MD5 now, *and if we continue to do so in the future*, then we can > ensure that current implementations will still be compatible with future > implementations that have removed support for DIGEST-MD5. > > However I don't understand why we are considering recommending weakening > the security of XMPP servers in the short and medium term by not > requiring any of DIGEST-MD5 or SCRAM or YAP. Are XMPP implementors > experiencing interoperability issues with DIGEST-MD5?
One problem we encountered when talking about JID escaping and actually trying it in the real world: http://thread.gmane.org/gmane.network.jabber.standards-jig/16309/focus=16466 The most obvious solution would be: Clients and Servers that have broken DIGEST-MD5 implementations should fix them ASAP. Problem with that solution is: Even if the SASL implementations are fixed fast (within few weeks) there will still be a lot of old servers out there and old clients. That of course causes no direct interop problems as noone uses \ in their JIDs yet. Robin
