ECDSA and first connection; bug?

[Damien Miller]

On Thu, 27 Jan 2011, Dan Kaminsky wrote:

> On Thu, Jan 27, 2011 at 3:20 PM, Damien Miller <djm at mindrot.org> wrote:
> > On Thu, 27 Jan 2011, Dan Kaminsky wrote:
> >
> >> Would this add a RTT?  SSH is a little slow as is.
> >
> > No, it would just be an informational message sent from the server to the
> > client probably right after the first SSH_MSG_NEWKEYS.
> 
> A message that said "BTW, here's my other host keys" would be
> excellent.  Question:  If we know the ECC key for something, should we
> no longer respect the RSA/DSA key?  My understanding is the ECC key is
> stronger.

In OpenSSH 5.7, the preference order is:

#define KEX_DEFAULT_PK_ALG      \
        "ecdsa-sha2-nistp256-cert-v01 at openssh.com," \
        "ecdsa-sha2-nistp384-cert-v01 at openssh.com," \
        "ecdsa-sha2-nistp521-cert-v01 at openssh.com," \
        "ssh-rsa-cert-v01 at openssh.com," \
        "ssh-dss-cert-v01 at openssh.com," \
        "ssh-rsa-cert-v00 at openssh.com," \
        "ssh-dss-cert-v00 at openssh.com," \
        "ecdsa-sha2-nistp256," \
        "ecdsa-sha2-nistp384," \
        "ecdsa-sha2-nistp521," \
        "ssh-rsa," \
        "ssh-dss"

-d