Last Call Review of draft-ietf-pcp-upnp-igd-interworking-07
review-ietf-pcp-upnp-igd-interworking-07-secdir-lc-roca-2013-05-02-00

Hello,

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.

--

1- Authors refer to [IGD2] (which is produced by UPnP), saying that the
authorization framework

defined there SHOULD be used. However I haven't found the description of such a
framework

in [IGD2] (I've looked at the Content Table and searched "Authorization"
keyword). Can you be

more explicit in your reference?

Additionally  [IGD2] says (p.10):

        "IGD 2 introduces access control features. [IGD2] RECOMMENDS access
        control requirements

        and authorization levels to be applied by default. However, devices MAY
        choose a different

        security policy,"

I do not understand the consequences of devices choosing a different security
policy, and how it

relates to your I-D.

then, same page:

        "In the 2-box model, where the control point is in the same device that
        desires to receive

        communication through the NAT, [IGD2] RECOMMENDS that access control is
        not needed. But in

        the 3-box model, where the control point is configuring NAT port
        mappings for a third device,

        [IGD2] RECOMMENDS that authentication and authorization is used."

It's not clear to me in which case of [IGD2] your I-D corresponds to.

2- It is said:

"Means to prevent a malicious user from creating mappings on behalf of a third
party must be enabled

as discussed in Section 13.1 of [I-D.ietf-pcp-base]."

What are the means mentioned? If I look at 13.1 of this reference, I see that
the THIRD_PARTY option

"MUST NOT be implemented or used" unless the network is trusted, and the
example of trusted network

is the case where there's an ACL on PCP client/PCP server/network.

Can you be more explicit in your recommendations?

3- You reference [Sec-DCP] but do not provide the URL, nor version number.
Since this is an external

document, it would be great.

Also, the one I found (

http://upnp.org/specs/gw/UPnP-gw-DeviceProtection-v1-Service.pdf

accessible from page

http://upnp.org/specs/gw/deviceprotection1/

) is from Feb. 2011, not 2009.

4- I don't see any threat model in this Security Discussions section.

There's good one in [I-D.ietf-pcp-base], but this is a different protocol,
deployed differently.

What can we say for the IWF itself?

There are some elements in this section, some pointers, but I don't get any
clear idea of the

situation.

--

Otherwise, regardless of any security consideration:

5- Fig. 1 mentions UPnP control point. Other figures of Section 3 mention IGD
control point.

Is it the same? If yes, can you harmonize?

This figure also remains somewhat mysterious to me. Can you add some more text
at the end of

the first paragraph of Introduction. And why does this figure appear after the
"two configurations"

discussion?

6- Introduction: you mention that two configurations are possible. Do you
consider both of them?

What are the consequences of these two configurations on IWF?

As such, reading this introduction did not help me so much understanding the
proposal. Section 3

is much better from that point of view.

Cheers,

  Vincent