Frank,

Elaborating on:

4 - would be nice to have a mechanism to encrypt the Contact URI in the 
response, specifically for the caller. An incoming request to a contact that 
was sent encrypted gives higher trust. At least it should be integrity 
protected somehow.

Suppose the UAS would include a new header "Secure-Contact" containing a 
contact URI encrypted using a key that the caller passed in its CONNECT 
request. That would provide:
- a means for the UAC to check the integrity of the contact
- a means for the UAS to verify that the caller is the same as the party 
that CONNECTed before (i.e. by including some unique bits in the contact 
URI)
- a way to avoid B2BUA elements blocking CONNECT by not forwarding the UAS 
Contact header


Furthermore, the draft could talk about how the UAS could specify a 
different machine than itself, for example a proxy with which it maintains 
an outbound connection. This could be a different proxy than the one through 
which the CONNECT came in. It could also be a proxy with which the UAS 
maintains a non-SIP connection (say a VPN/IPSec connection). Such a proxy 
might not be able to present a certificate on behalf of the UAS, but at 
least it would provide a mechanism to side step the SIP proxy infrastructure

Regards,
Jeroen 
_______________________________________________
Sip mailing list  https://www1.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

Reply via email to