Re: about R1bis

[Erik Nordmark <erik.nordmark@sun.com>]

marcelo bagnulo braun wrote:

> So, the proposal would be to:
>
> Define a new type of messages: R1bis
> Define types of validator mechanisms , which are identified by the 3 
> most significant bits of the validator value

So 3 bits instead of 1 bit is so that we can have some future extensibility?

> Define an alternative validator mechanism for this message, that 
> includes as inputs the following values:
> - the Secret S
> - The responder (B) nonce
> - the locator pair
> - the context tag contained in the received packet (CTpac)
> Define that the initiator nonce used for R1bis packets is the hash of 
> the locator pair and CTpac

Good suggestion.

> Define generation and processing of the R1bis packet accordingly.

I guess there is a detail which is whether R1bis is a different message 
type than R1, or whether use a bit in R1 to indicate bis vs. normal.
My suggestion is to use a different message type for R1bis.

>      - Perhaps A is already using this context tag for another
>        context. In this case, A simply starts a regular 4 way
>        handshake to establish the context again
>    I guess that the last option seems the preferred alternative... 

Hopefully the case when the context tag is use we have the option to use 
the "context confusion" recovery mechanism, which handles other cases 
when a context tag has been reused...

I have to think about this some more.

   Erik