Re: [kitten] Comments on draft-ietf-kitten-password-storage-04

[Sam Whited <[e-mail]>]

Thank you for your feedback! I think I have addressed all of these
issues (and will upload a new version soon) except for:

On Sat, Mar 20, 2021, at 20:31, Jim Fenton wrote:
> 4.1: I’m concerned that the MUST NOT here conflicts with the SHOULD
>      NOT regarding OBSOLETE and LIMITED mechanisms in Section 2. Of
>      course, MD5 is not an SASL mechanism per se, and “support any
>      mechanism” in this context may not necessarily mean an SASL
>      mechanism, but I still found this vaguely confusing.

I thought of this as just further refining the guidance from section 2.
You SHOULD NOT use anything from a specific list, and MUST NOT use
anything that meets these criteria (which may include things that are on
the list and things that aren't). However, perhapse the SHOULD NOT in
section 2 should become a MUST NOT? Re-reading it I'm not sure why I put
SHOULD NOT there.

> 5.2: Bcrypt is no longer the current (top) OWASP recommendation.

Interestingly, I had argon2id as the top recommendation in an
earlier draft of this document then they changed it back to bcrypt.
I'll swap it back.

> 7: Suggest saying something about Unicode characters and password
>    length

Good idea. I updated this to suggest counting grapheme clusters,
which I believe is going to be better than counting scalar values,
but I'm not sure that it's ideal either. Many languages probably
don't have an implementation of the segmentation algorithm, and it
adds a lot of complexity to calculating password lengths. Other
suggestions welcome. Because of the uncertainty I did not use any
normative language here for now.

I also couldn't find an existing reference for Unicode Standard Annex
reports. Is there a bibliography somewhere that includes these which I
could reference instead of making up a new ref?

—Sam


-- 
Sam Whited