Re: [rtcweb] Resolving RTP/SDES question in Paris

[Randell Jesup <[e-mail]>]

On 3/19/2012 12:10 AM, Ejzak, Richard P (Richard) wrote:
> I would like to argue two points: 1) DTLS-SRTP with IdP is the only
> media security scheme that rtcweb should support; and 2) rtcweb should
> also support RTP (no media security) with a clear requirement on the
> browser UI to warn the user of the complete lack of media security.
>
> DTLS-SRTP

[SNIP]

I generally agree.

> RTP
>
> There are too many reasonable use cases for unsecured media for us to
> ignore them. The browser should be very clear when media security is
> unavailable and make it easy to prevent communication without media
> security (perhaps as a default setting), but there are legitimate use
> cases in various private environments (e.g., enterprise, jail) where
> media security may not be allowed (or must somehow be compromised), or
> is just not available, that we should just support straight RTP. As long
> as the user can control the conditions under which media security is
> disabled, I do not see a problem.

The issue with "legacy" RTP is more one of controlling 'consent', such 
that we can avoid a WebRTC endpoint being used as a DDoS client.  I 
spent many hours trying to find a way around the issue, and only found 
ones that involve some level of modification to the target RTP client or 
its network (and still have serious issues).

For your case (not necessarily 'legacy', but needs-to-be-in-the-clear), 
perhaps there are other solutions.

One would be the command-line switch to force a NULL SRTP cipher.

An enterprise could use a WebRTC gateway, which in the context of WebRTC 
the user could provide their IdP credentials to (or the enterprise could 
be the IdP itself); or just act as a WebRTC MITM without bothering with 
IdP support.  Certainly there are usecases for keeping media traffic 
within an enterprise encrypted - I remember getting router-traffic dumps 
at an old company and being able to replay RTP conversations, including 
sensitive ones with external council, board members, HR, etc.  Modern 
switched setups make this tougher for J-random-employee to do, but far 
from impossible, and trivial for anyone working in networking IT or with 
physical access to switches or wiring.

-- 
Randell Jesup
[e-mail]