HEADS UP: OpenSSH with DNSSEC support in 10

Ian Lepore ian at FreeBSD.org
Wed Sep 11 15:25:57 UTC 2013


On Wed, 2013-09-11 at 17:00 +0200, Dag-Erling Smørgrav wrote:
> OpenSSH in FreeBSD 10 is now built with DNSSEC support, unless you
> disable LDNS in src.conf.  If DNSSEC is enabled, the default setting for
> VerifyHostKeyDNS is "yes".  This means that OpenSSH will silently trust
> DNSSEC-signed SSHFP records.  I consider this a lesser evil than "ask"
> (aka "train the user to type 'yes' and hit enter") and "no" (aka "train
> the user to type 'yes' and hit enter without even the benefit of a
> second opinion").
> 
> DES

So what happens when there is no dns server to consult?  Will every ssh
connection have to wait for a long dns query timeout?

What if the machine is configured to use only /etc/hosts?

What if a DNS server is configured but doesn't respond?

For that matter, I just realized I'm a bit unclear on who is querying
DNS for this info, the ssh client or the sshd?

-- Ian




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