Re: [precis] Gen-art last call review of draft-ietf-precis-7613bis-07

[Peter Saint-Andre - Filament <[e-mail]>]

On 6/26/17 5:48 PM, Peter Saint-Andre - Filament wrote:
> Hi Linda,
> 
> Thanks for your review. Comments inline.
> 
> On 6/26/17 4:53 PM, Linda Dunbar wrote:
>>  
>> Reviewer: Linda Dunbar
>> Review result: Ready
>>  
>> I am the assigned Gen-ART reviewer for this draft. The General Area
>> Review Team (Gen-ART) reviews all IETF documents being processed by the
>> IESG for the IETF Chair.  Please treat these comments just like any
>> other last call comments.
>>  
>> For more information, please see the FAQ at
>>  
>> <https://trac.ietf.org/trac/gen/wiki/GenArtfaq>.
>>  
>> Document: draft-ietf-precis-7613bis
>> Reviewer: Linda Dunbar
>> Review Date: 2017-06-25
>> IETF LC End Date: 2017-06-27
>> IESG Telechat date: 2017-07-06
>>  
>> Summary:
>> The document is written very clear. Even for a person who is not
>> familiar with the App area, I can follow through the description. The
>> document is ready for publication as standard track document Major issues:
>>  
>> One Minor issue:
>>  
>> Page 6 last paragraph has:
>> /SASL mechanisms SHOULD delay any case////mapping to the last possible
>> moment, such as when doing a lookup////by username, performing username
>> comparisons, or generating a////cryptographic salt from a username (if
>> the last possible moment////happens on the server, then decisions about
>> case mapping can be a////matter of deployment policy). In keeping with
>> [RFC4422], SASL////mechanisms are not to apply this or any other profile
>> to////authorization identifiers, only to authentication identifiers./
>>  
>> What does "last possible moment" mean? When I read it, I thought it
>> meant wait until you got all the characters. But the next sentence
>> mentions "..happens on the server". How is the "server" related to the
>> entity that check the user name & password? 
> 
> Many authentication decisions happen on an application server to which a
> user-oriented client connects (think of an email client connecting to an
> email server). By "last possible moment" we're referring to processing
> within the application server or an authentication module thereof - for
> instance, instead of performing case mapping on first receiving data
> from the client (thus implying that the case information is lost through
> most of the processing stages), it's better to lose that information
> only at the very end. Do you feel it would it help to add a more
> detailed description of the reasoning here?

Here is a proposed adjustment to the text:

OLD

      SASL mechanisms SHOULD delay any case
      mapping to the last possible moment, such as when doing a lookup
      by username...

NEW

      Because case mapping results in
      information loss, in order to retain that information for as long
      as possible during processing, implementations SHOULD delay any
      case mapping to the last possible moment, such as when doing a
      lookup by username...

Peter