Re: [rtcweb] WGLC for draft-ietf-rtcweb-ip-handling

[Ted Hardie <[e-mail]>]

Question as chair:

On Tue, Mar 27, 2018 at 9:57 AM, Cullen Jennings <[e-mail]> wrote:

>
> There are several people who's opinion I deeply respect that have looked
> at this problem in detail. They somewhat agree the above is a problem, but
> they argue it is better than any alternative design. I disagree with
> this.The root of the problem we are trying to solve with this draft is that
> some VPNs are configured to send some packets over the VPN while at the
> same time some other packets are not sent over the VPN. If you use a VPN
> configured like this to try and hide your location, WebRTC can end up
> sending packets not over the VPN and that can reveal your location. I think
> the right solution to this problem is to acknowledge this is a VPN problem,
> not a WebRTC problem. If you are using a VPN to hide your location, do not
> allow that VPN to send packets outside the VPN. I will note most VPNs
> support this.
>
>
The document's current description of this problem is:

       If the client is multihomed, additional public IP addresses for
       the client can be learned.  In particular, if the client tries to
       hide its physical location through a Virtual Private Network
       (VPN), and the VPN and local OS support routing over multiple
       interfaces (a "split-tunnel" VPN), WebRTC will discover not only
       the public address for the VPN, but also the ISP public address
       over which the VPN is running.

Would adding a statement such as "Users desiring maximum privacy should
avoid split-tunnel configurations when they are in control of that
configuration" help?

Ted