OpenSSH Key Storage

Nicolas Williams Nicolas.Williams at
Sat Feb 2 06:37:19 EST 2002

On Fri, Feb 01, 2002 at 01:58:22PM -0500, Carson Gaspar wrote:
> Can anyone find a flaw in my analysis? Did I miss any corner cases?

With (b) the client can verify that the server is who it claims to be,
but not whether that is who the user wanted to connect to.

So an attacker could redirect the client to a different host than the
user meant, and the client will think all's ok. The client would have to
check that the server's claimed name is different than the one the user
asked for and would then have to prompt the user - or look up the
server's claimed name in an aliases list and check the user's requested
server name against the server's aliases.

Let's not kid ourselves - if you use DNS and not DNSSEC or something
better, then you have the same problem: an attacker can spoof a DNS
response while ssh is looking up the user's requested server name and
point the ssh client at a different host withot the client or the user
being any the wiser.

BUT, DNS spoofing is a problem external to SSH and can be fixed without
changing SSH.

> -- 
> Carson


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