Re: flow label demultiplexing

[Iljitsch van Beijnum <iljitsch@muada.com>]

On 18-apr-05, at 18:21, marcelo bagnulo braun wrote:

> So, when you use CGA capabilities of the address, the CGA parameter 
> data structure is exchanged upfront and it contains the public key.

> Next, the node can use a new address (that was not included in the CGA 
> parameter data structure) because it can authorize it by signing it 
> with the private key corresponding to the CGA. Moreover, such 
> signature could even be included in a packet that contains the new 
> address as source address (i think)

But what exactly is signed here? I guess the whole packet, including 
the source address. A man in the middle would be able to modify 
anything that isn't signed. And even then, accepting a packet from an 
unknown source is dangerous because it can lead to a DoS against the 
CPU.

A system where the receiver challenges the sender would be MUCH better 
because that way we have return routability before spending serious CPU 
time.