Re: draft-ietf-sip-record-route-fix-08 Changes

On Aug 14, 2009, at 9:31 AM, Olle E. Johansson wrote:

>
> 13 aug 2009 kl. 23.12 skrev Dean Willis:
>>
>>
>> Hmm. Could it be that since SIPS (draft-ietf-siip-sips) requires  
>> e2e TLS even more strongly than did 3261 for original sips URIs. So  
>> if a URI used in a record-route resolves both TLS and non-TLS,  
>> there's a possibility that the return stroke might not use TLS,  
>> thereby breaking the e2e TLS requirement. But your proposed wording  
>> change seems to have the same effect.
>>
>
>
> I did not read the draft as SIPS requiring e2e TLS. We still use  
> proxys and have clear communication within the proxy. E2E to me is  
> UAC -> UAS with encryption ALL the way and no middleman.
>
> Did I misunderstand?


It kind of  on what you mean by "end to end". Draft-ietf-sip-sips  
requires that TLS be used on every hop whenever a SIPS  URI is used,  
whereas RFC 3261 allowed an exemption for the "last hop". In the  
language of the discussion at the time, this was considered "end to  
end TLS" even though it wasn't "UA to UA TLS".

Under 3261, one could legitimately double record route at a proxy  
performing contact routing with a first route entry having a SIPS URI  
and a second having a SIP URI.

With draft-ietf-sip-sips, that behavior is forbidden if the result  
would be to fail to use TLS on the route-segment indicated with a SIPS  
URI.

The record-route-fix document is essentially promoting a very special  
exception by noting that it is possible to construct a SIP URI such  
that resolution of the SIP URI using the procedures of RFC 3263 would  
guarantee that TLS is used, even though the URI itself is SIP instead  
of SIPS.

Consequently, the working I suggested was intended to convey the idea  
that the "special SIP URI" MUST resolve only to TLS and MUST NOT  
resolve to a hop that would not use TLS, since the only case in which  
we RFC 3261 would have allowed us to not use TLS was deprecated by  
draft-ietf-sip-sips.

--
Dean



_______________________________________________
Sip mailing list  https://www.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use [email protected] for questions on current sip
Use [email protected] for new developments on the application of sip