Secdir last call review of draft-ietf-rtgwg-net2cloud-problem-statement-36

[Deb Cooley via Datatracker <[e-mail]>]

Reviewer: Deb Cooley
Review result: Has Issues

Reviewer: Deb Cooley

Review result: Has Issues

I have reviewed this document as part of the security directorate's ongoing
effort to review all IETF documents being processed by the IESG.  These
comments were written primarily for the benefit of the security area directors.
 Document editors and WG chairs should treat these comments just like any other
last call comments.

Document: draft-ietf-rtgwg-net2cloud-problem-statement-36

Reviewer: Deb Cooley

Review Date: 2024-03-01 (sort of last call)

The summary of the review is:

1.  Section 5.1, paragraph 2:  Certainly the principles and assumptions of RFC
4535* would apply to any group key management situation (note the word change
from 'group encryption' to 'group key management').  The specific protocol
addressed by that RFC isn't being used here (even though they mention ISAKMP).
How about something like this:

"The group key management protocol documented in [RFC4535] outlines the
relevant security risks for any group key management system in Section 3
(Security Considerations).  While this particular protocol isn't being
suggested, the drawbacks and risks of group key management are still relevant."

2.  Section 5.1, paragraph 3:  The draft referenced here is expired and the
security of the methods would have to be reviewed.  (that is listed in Section
7)

3.  Section 5.2:  The draft referenced in this section is (currently) an
individual draft, and again the security of the methods would have to be
reviewed. (I see that WG adoption has been requested, and the draft is listed
in Section 7).

4.  Section 5.2, para 2:  nit:  Please spell out SRH and VxLAN.

5.  Section 7, second to last bullet:  Please see my comments on Section 5.1. 
I would use the words 'group key management' vice 'group encryption'.  It is
the key management of a group system that is tricky and problematic, not the
actual encryption per se. Something like this perhaps:

"Group key management comes with security risks such as:  keys being used too
long, single points of compromise (one compromise affects the whole group), key
distribution vulnerabilities, key generation vulnerabilities, to name a few. 
[RFC4535] outlines the security risks in Section 3 (Security Considerations). 
While this specific protocol isn't being suggested the risks and
vulnerabilities apply to any group key management system."

6.  Section 7, last bullet:  Change 'improved IPsec tunnel management' to
'scaling IPsec tunnel management' to match the heading for Section 5.1.

7.  Note:  there are at least 3 expired drafts referenced as informational by
this draft (1 of them is suggested as a security improvement).  It looks
unusual to my eye.  Again, either the WG or the IESG should weigh in.

 * RFC 4535: Thanks for that blast from the past, it has been decades since
 I've seen some of those authors names.