Re: [xmpp] WGLC Comments on 6122bis

On 10 Mar 2015, at 19:51, Ben Campbell wrote:

> -- 3.3, implementation note:
>>>>
>>>> Are there any practical consequences for the implementor? Are there
>>>> potential conflicts where the XMPP implementation correctly forms a
>>>> Localpart, but it contains an identifier that is interpreted
>>>> incorrectly by some SASL mechanism?
>
>
>>
>> Re-using the UsernameCaseMapped profile from 
>> draft-ietf-precis-saslprepbis should help in this regard. However, as 
>> noted, some SASL mechanisms might not be upgraded quickly and thus 
>> would still use SASLprep (RFC 4013). The differences are explained a 
>> bit more in Appendix A of draft-ietf-precis-saslprepbis - as I see 
>> it, the only semi-major issue is that certain characters that were 
>> "mapped to nothing" in RFC 4013 are simply disallowed by the 
>> UsernameCaseMapped profile that we re-use in 6122bis.
>
>
> So an identifier created with UsernameCaseMapped should be fine, but 
> an identifier created somewhere else in sasl might not be legal? That 
> _seems_ unlikely to be a problem...

I realized shortly after sending this that that made no sense. It seems 
more likely that you would run into a previously created identifier that 
followed older rules--but you already discuss that in the intro.

Even so, it still might not hurt to mention the appendix.

>
> It might not hurt to mention the saslprepbis appendix in the note.