Subject: [http-auth] review of draft-ietf-httpauth-digest-15.txt

From: Francis Dupont <[email-masked]>
Date: Mon, 06 Apr 2015 19:58:42 +0200

I am the assigned Gen-ART reviewer for this draft. For background on
Gen-ART, please see the FAQ at

<http://wiki.tools.ietf.org/area/gen/trac/wiki/GenArtfaq>.

Please resolve these comments along with any other Last Call comments
you may receive.

Document: draft-ietf-httpauth-digest-15.txt
Reviewer: Francis Dupont
Review Date: 20150402
IETF LC End Date: 20150402
IESG Telechat date: unknown

Summary: Ready

Major issues: None

Minor issues: None

Nits/editorial comments:
 I reviewed the 15 version but I can see the 16 one is already available
so I'll try to update my comments.

 - first I was a bit surprised nobody just asked to jump to HTTPS (or
  HSTS) but reading the document it seems there are still good use
  of the digest authentication scheme...

 -  3.3 page 5: IMHO the "opaque" field is clearly a nonce
  (i.e., more a nonce than the "nonce" field) but I understand this
  was inherited from RFC 2617...

 - 3.3 page 7 (algorithm, twice) and some other places:
  e.g. -> e.g.,

 - 3.3 page 7 (algorithm): I noted the algo protocol is still
  a keyed one vs. HMAC (cf. AH which switched from keyed to HMAC
  between RFC 1826 and RFC 2402) but I believed you have a good
  reason to do this (and the secdir will say if it is OK anyway).

 - 3.4.2 page 11: e.g. -> e.g., (again but this one is at the end of a line)

 - 3.4.2 page 11: cnounce -> cnonce

 - 3.4.2 page 11: the presentation of this definition is very
 misleading:

         A1       = H( unq(username) ":" unq(realm)
                        ":" passwd )
                        ":" unq(nonce-prime) ":" unq(cnonce-prime)

  I strongly suggest something like:

         A1       = H( unq(username) ":" unq(realm) ":" passwd )
                        ":" unq(nonce-prime) ":" unq(cnonce-prime)

 - 3.4.2 page 11: the server need only use
                                 ^ needs

 - 3.5 page 14: affects -> effects

 - 5.2 page 21: this information need not be decrypted
                                     ^ needs

 - 6.1 page 27: can you instantiate the RFC XXX:
  MD5: RFC 1321
  SHA-256: FIPS 180-2
  SHA-512/256: FIPS 180-4?

 - A page 30: negotitation -> negotiation

Regards

[email-masked]

---

From: Rifaat Shekh-Yusef <[email-masked]>
Date: Mon, 6 Apr 2015 16:01:22 -0400

Hi Francis,

Thanks for your review and comments. I will address the nits in the next
version of the draft.
Please, see my reply to some of your comments inline...

Regards,
 Rifaat

>   reason to do this (and the secdir will say if it is OK anyway).
Good question.
Using HMAC would impact the H(A1) calculation and the KD function, but it
would definitely work.
If there is interest and support for adding HMAC, I would be happy to do
that.

>                         ":" unq(nonce-prime) ":" unq(cnonce-prime)
Sure.

>  - 6.1 page 27: can you instantiate the RFC XXX:
The RFC used in the table should point to the current draft which does not
have an RFC # yet.
Kathleen has already raised an issue about this and she suggested a text
that was added to v16.

Regards,
 Rifaat