Re: [secdir] Review of draft-ietf-pce-lsp-control-request-07

[Dhruv Dhody <[e-mail]>]

Hi Shawn,

<adding WG>

Thanks for your security review and comments.

On Mon, Aug 19, 2019 at 6:17 AM Shawn Emery <[e-mail]> wrote:
>
> Reviewer: Shawn M. Emery
> Review result: Ready
>
> 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.
>
> This draft specifies an extension to the Path Computation Element communication
> Protocol (PCE) that allows a PCE to request control of Label Switched Paths (LSPs).
>
> The security considerations section does exist and discusses a new DoS vector
> that this draft creates.  The attack involves sending control requests for delegate
> control of all of its LSPs to the Path Computation Client (PCC).  The proposed
> solution is to set a threshold rate of the delegation requests for the PCC per PCE.
> I agree with the proposed solution, though I don't know if guidance can be provided
> on what these thresholds would be per environment.
>

As you noted the document does not provide default for the threshold
as it dependent on the deployment/environment. The same is true for
RFC 8231.

> The section goes on to refer to RFC 8231 to justify that the PCP extension should
> be deployed with authenticated and encrypted sessions in TLS using RFC 8253.
> I agree with this prescription as well else an attacker would now be able to take
> control over all local LSPs with this extension.  I think that this should at least be
> stated if an attacker is able to compromise a PCE.
>

The security consideration includes "...either by spoofing messages or
by compromising the PCE itself".

> General comments:
>
> None.
>
> Editorial comments:
>
> s/sends PCRpt/sends a PCRpt/
> s/also specify/also specifies/
> s/all its/all of its/
> s/If threshold/If the threshold/
> s/explicitly set aside/explicitly excluded/
>

Thanks for these, request authors to handle them.

Thanks!
Dhruv

> Shawn.
> --