Re: Secure legacy authentication for IKEv2

[Paul Hoffman / VPNC <paul.hoffman@vpnc.org>]

At 3:06 PM +0300 12/20/02, Valery Smyslov wrote:
>draft suggests that no negotiation of LAM type is possible between client
>and server:
>server can just accept or reject LAM type that client proposed, and he has
>no means
>to indicate to client which LAM type he is willing to do. This can lead to
>situation,
>when client will have to perform up to 4 connection attempts with different
>LAM types.
>Not only will it delay the connection setup, but also it will put an
>unnecessary load
>to server - for each attempt he will have to do both DH and RSA/DSA.

Er, do you really think that the client and server haven't agreed out 
of band which legacy auth mechanism they will do? In the real world, 
companies tell their users which auth mechanism they will use, and 
the information needed to do it.

>I think better way to handle this situation is to allow server to change LAM
>type
>if he doesn't like what client proposed.

This adds a lot of complexity for a usage model that no one seems to 
have. Am I wrong here? Do any of the VPN makers out there have 
customers who want to do legacy auth negotiation?

--Paul Hoffman, Director
--VPN Consortium