Re: [Gen-art] Gen-ART Review for draft-ietf-xmpp-6122bis

[Peter Saint-Andre - &yet <[e-mail]>]

On 5/28/15 1:03 AM, Romascanu, Dan (Dan) wrote:
> Hi,
>
> What is missing in my opinion are more details for the operators
> about what tests can be made in order to avoid compatibility and
> migration problems. The text in  draft-ietf-xmpp-6122bis-22 says:
>
>> Because it is
> possible that previously-valid JIDs might no longer be valid (or
> previously-invalid JIDs might now be valid), operators of XMPP
> services are advised to perform careful testing before migrating
> accounts and other data.
>
> What does this 'careful testing' include so that operators avoid
> problems for the XMPP and XMPP applications users?  Can we be more
> precise? Section 6.1 in draft-ietf-precis-saslprepbis (which needs to
> be referred here) seems to provide indications for application
> developers to avoid incompatibilities - this is fine. What needs an
> operator with an installed base of 'legacy' 6122  do and test?

As I just wrote to you and Benoit and Joel in a private email within a 
parallel thread...

The "careful testing" we had in mind for XMPP involves just what is 
discussed in Section 6.1 of draft-ietf-precis-saslprepbis:

1. Looking for account names that have Unicode code points with 
compatibility equivalents (e.g., U+017F LATIN SMALL LETTER LONG S and 
U+2163 ROMAN NUMERAL FOUR) - this is the major concern.

2. Looking for account names that have Unicode code points from the 
PrecisIgnorableProperties (M) category defined in Section 9.13 of RFC 
7564 (e.g., U+00AD SOFT HYPHEN) - these are less likely to have ever 
been allowed in account names but I suppose it's possible (and they 
would have been "mapped to nothing" in Stringprep so in practice a user 
would not notice the difference if under PRECIS those code points are 
removed).

3. Applying either the UsernameCaseMapped or UsernameCasePreserved 
profile to all account names.

If Section 6 of draft-ietf-precis-saslprepbis is complete, then 
referencing that section from draft-ietf-xmpp-6122bis should be 
sufficient - perhaps with some more explanatory text as above, 
preferably in the saslprepbis document because it would be helpful to 
operators of any application service that used SASLprep (putting that in 
the XMPP document won't help operators of non-XMPP services).

Peter

>
> Thanks and Regards,
>
> Dan
>
>
>> -----Original Message----- From: Peter Saint-Andre - &yet
>> [mailto:[e-mail]] Sent: Wednesday, May 27, 2015 7:04 PM To:
>> Romascanu, Dan (Dan); General Area Review Team Cc:
>> [e-mail] Subject: Re: Gen-ART
>> Review for draft-ietf-xmpp-6122bis
>>
>> Hi Dan, thanks for the review. Comments below.
>>
>> On 5/27/15 7:00 AM, Romascanu, Dan (Dan) wrote:
>>> I am the assigned Gen-ART reviewer for this draft. For background
>>> on Gen-ART, please see the FAQ at
>>>
>>> <https://urldefense.proofpoint.com/v2/url?u=http-
>> 3A__wiki.tools.ietf.org_area_gen_trac_wiki_GenArtfaq-0A&d=AwID-
>> g&c=BFpWQw8bsuKpl1SgiZH64Q&r=I4dzGxR31OcNXCJfQzvlsiLQfucBXRucPvd
>> rphpBsFA&m=HAGYK5DCyp4ZrASnAfyBHWxiG_skpr2T7P71C9h1s8I&s=xE06r
>> -tOf3XD6VjtlB31ercDLaBN3lIdKjpqO-YALV8&e= >
>> <https://urldefense.proofpoint.com/v2/url?u=http-
>> 3A__wiki.tools.ietf.org_area_gen_trac_wiki_GenArtfaq&d=AAMFAw&c=BF
>> pWQw8bsuKpl1SgiZH64Q&r=I4dzGxR31OcNXCJfQzvlsiLQfucBXRucPvdrphpBs
>> FA&m=r8UFfP-
>> NUIqoQixcKqofblfdzNSaZvjkRfw3L7VsyHc&s=DCDmXhyc7XoNYI-
>> SEtLco1iUd9vIjB8nxVWrudr4dV0&e=>>.
>>>
>>> Please resolve these comments along with any other Last Call
>>> comments you may receive.
>>>
>>> Document:
>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__art.tools.ietf.or
>>>
>>>
g_tools_art_genart_index.cgi_t-3D965_doc-3Fselected-5Fdoc-3Ddraft-
>> 2Die
>>> tf-2Dxmpp-2D6122bis&d=AwID-
>> g&c=BFpWQw8bsuKpl1SgiZH64Q&r=I4dzGxR31OcNXC
>>>
>> JfQzvlsiLQfucBXRucPvdrphpBsFA&m=HAGYK5DCyp4ZrASnAfyBHWxiG_skpr2
>> T7P71C9
>>> h1s8I&s=3PpWUOBw12kraQlL6gjxpgjwXG-4OvUwcK6jAOwEpd0&e=
>>>
>>> Reviewer: Dan Romascanu
>>>
>>> Review Date: 5/27/15
>>>
>>> IETF LC End Date: 6/3/15
>>>
>>> IESG Telechat date:
>>>
>>> Summary:
>>>
>>> Ready with one issue which I believe is worth discussing.
>>>
>>> Major issues:
>>>
>>> I have a concern about backwards compatibility and migration. In
>>> the migration between 6122 and 6122bis deployments it is possible
>>> that previously-valid JIDs might no longer be valid or
>>> previously-invalid JIDs become valid. Because of this the
>>> Introduction says that operators of XMPP services are advised to
>>> perform careful testing before migrating accounts and other
>>> data.
>>>
>>> In a dialog with Peter Saint-Andre (document author) I asked if
>>> there are any recommendations that could be made to the
>>> application designers and operators respectively to ease the
>>> migration?
>>>
>>> His answer pointed to section 6 (actually I think that 6.1
>>> applies) in in draft-ietf-precis-saslprepbis. I believe that a
>>> pointer to that section in a 'migration / backwards
>>> compatibility' section would be useful for the application
>>> designers. What about the operators, however? Can more details
>>> about what operator should test to ensure compatible migration of
>>> users and applications be provided  beyond what is mentioned in
>>> the introduction?
>>
>> We tried to make Section 6 of draft-ietf-precis-saslprepbis focused
>> on the needs of operators, not application designers. (I happen to
>> be the operator of a relatively large instant messaging service
>> that will need to do some testing and possibly some data munging
>> when we migrate our account data from Stringprep to PRECIS, so I
>> wrote that text with my operator hat on.) If the text in
>> draft-ietf-precis-saslprepbis is not complete enough, then we need
>> to figure that out now because it's on the IESG telechat tomorrow.
>> I do think that's the right place to discuss the matter, because
>> draft-ietf-xmpp- 6122bis merely uses the UsernameCaseMapped profile
>> defined in that document.
>>
>> Peter
>>
>> -- Peter Saint-Andre
>> https://urldefense.proofpoint.com/v2/url?u=https-
>> 3A__andyet.com_&d=AwID-
>> g&c=BFpWQw8bsuKpl1SgiZH64Q&r=I4dzGxR31OcNXCJfQzvlsiLQfucBXRucPvd
>> rphpBsFA&m=HAGYK5DCyp4ZrASnAfyBHWxiG_skpr2T7P71C9h1s8I&s=ZrGi4
>> ShVndAjMY4s7wYilRtegOfs8l0lX-OPtejBQS8&e=