Re: [hybi] Handshake was: The WebSocket protocol issues.

[Ian Hickson <[e-mail]>]

On Mon, 11 Oct 2010, James Graham wrote:
> 
> So there is an underlying issue here that I don't understand. It seems 
> clear to me that Adam and Eric's proposed handshake has a better 
> security story with regard to cross-protocol attacks than -75, -76, or 
> any other proposal other than using NPN with TLS. However there seem to 
> be a number of people who have problems with this proposed handshake to 
> the extent that they are prepared to forgo the security properties in 
> order to get something different. In general people seem to be aware 
> that they are making the security weaker since the arguments are mostly 
> about how different approaches will probably be good enough in practice 
> even though they are theoretically inferior.
> 
> What I haven't followed is what the problems with the proposal actually 
> are. I understand that I have likely missed these in other messages, but 
> it would be helpful if people who believe that the proposed approach, or 
> aspects of it, are unworkable could summarise the outstanding issues 
> they see.

I would like to ask a similar question, but to the people proposing Adam 
and Eric's latest proposed handshake. What real problem does it solve that 
NPN with TLS doesn't solve? As you say, it is weaker than NPN with TLS, so 
why not just go all the way?

This would have multiple advantages beyond just being more secure, for 
example we could halve the number of schemes we're introducing, halve the 
number of handshake implementations on both clients and servers, greatly 
reduce the testing burden, etc.

-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'