AFS and tokenforwarding

[Markus Friedl]

On Thu, Oct 04, 2001 at 09:15:23PM +0200, Bjoern Groenvall wrote:
> Nicolas> If the token is forwarded before authentication then you
> Nicolas> don't know if the server is really who you think it is, so
> Nicolas> you might be forwarding your token to an impostor. Ooops.
> 
> I don't think any of the ssh (at least v1) authentication mechanisms
> really authenticate the server.

this depends on how the host key is authenticated. server
authentication is as strong as the host key authentication.

> A masquerading server can always
> forward the authentication information to the real server and use that
> response as a legitimate reply. Thus you may still be passing
> credentials down to an impostor. Either way you do it, you can always
> be fooled. A similar problem exists with the common "pass passwords in
> the clear" methods used by ssh. Hopefully this is fixed in v2 but I
> never really bothered to check.

same thing can happen in ssh v2 unless you use pubkey authentication.
successful pubkey authentication is only possible if there is no MITM.