Re: [netconf] Roman Danyliw's Discuss on draft-ietf-netconf-tls-client-server-39: (with DISCUSS and COMMENT)

[Kent Watsen <[e-mail]>]

Hi Roman,

Thank you for your comments.
Please find responses below.

Kent // author


> On Feb 28, 2024, at 9:13 PM, Roman Danyliw via Datatracker <[e-mail]> wrote:
> 
> Roman Danyliw has entered the following ballot position for
> draft-ietf-netconf-tls-client-server-39: Discuss
> 
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> 
> 
> ----------------------------------------------------------------------
> DISCUSS:
> ----------------------------------------------------------------------
> 
> As mentioned in the ssh-client-server draft, I struggle to understand when it
> is assumed that the security considerations of the imported modules apply, and
> when they will be surfaced as issues in the module that is using them.  With
> that confusion in mind:

We continue to have confusion.  Please see my comments in other threads.   But generally I’m flummoxed as to what is or isn’t “nam:default-deny-all”...



> ** Section 5.3 and 5.4
>   None of the readable data nodes defined in this YANG module are
>   considered sensitive or vulnerable in network environments.  The NACM
>   "default-deny-all" extension has not been set for any data nodes
>   defined in this module.
> 
>   Please be aware that this module uses the "key" and "private-key"
>   nodes from the "ietf-crypto-types" module
>   [I-D.ietf-netconf-crypto-types], where said nodes have the NACM
>   extension "default-deny-all" set, thus preventing unrestricted read-
>   access to the cleartext key values.
> 
> It is difficult for me to reconcile these two paragraphs.  The first says there
> is nothing read sensitive in this YANG module.  The second paragraph helpfully
> reminds us there are potentially sensitive private keys in the module. 
> Additionally, from an OPSEC perspective, knowing which client/EE certificates
> is held by a device might reveal information useful to an attacker.

You’re right.  I deleted the redundant/contradictory paragraph.  The goal is to be as DRY as possible, and so no repeat what to normatively stated elsewhere.  


> Section 5.4 has similar language.

Paragraph deleted here also.



> ----------------------------------------------------------------------
> COMMENT:
> ----------------------------------------------------------------------
> 
> Thank you to Barry Leiba for the SECDIR review.
> 
> ** Section 5.*
>     The protocol-accessible read-only node for the algorithms supported
>     by a server is mildly sensitive
> 
> What is meant by “mildly sensitive”?

Per a different IESG review thread, I removed this paragraph entirely, in both this draft and also the ssh-client-server draft.   First 1) because the data node was moved away from the IANA-maintained module to the “ietf-tls-common” module and, next, 2) because it didn’t make sense to add a Consideration because it says this already:

	None of the readable data nodes defined in this YANG module
	are considered sensitive or vulnerable in network environments.
	The NACM "default-deny-all" extension has not been set for any
	data nodes defined in this module.

Which applies to the “supported-algorithms” node as well.  They are not sensitive to authenticated clients.

Thoughts?


Thanks again,
Kent