Toad World® Forums

SSH Algorithm negotiation fail


#1

Hi,

When I try to SSH through toad edge, I get the following error in toad: “Cannot establish SSH connection: Algorithm negotiation fail”. On my SSH server, I see the following error:
Oct 17 04:33:44 xxxxxx sshd[17039]: fatal: Unable to negotiate with xxx.xxx.xxx.xxx port 61450: no matching key exchange method found. Their offer: diffie-hellman-group1-sha1,diffie-hellman-group14-sha1,diffie-hellman-group-exchange-sha1 [preauth]

When I enable these kex, it generates failures and warnings in my ssh security scan (https://github.com/arthepsy/ssh-audit):
(kex) diffie-hellman-group1-sha1 – [fail] removed (in server) since OpenSSH 6.7, unsafe algorithm
(kex) diffie-hellman-group-exchange-sha1 – [fail] removed (in server) since OpenSSH 6.7, unsafe algorithm
(kex) diffie-hellman-group14-sha1 – [warn] using weak hashing algorithm

diffie-hellman-group14-sha1 is only a warning at least, but still not great.

Do you have any plans on updating your SSH client library to support more recent algorithms?

Note: I am using out toad edge 2.0.3 on Mac OSX 10.14.

Thanks,
Chris


#2

Hi, we have created issue for this, we have to reproduce it first, we will let you know about the progress.
thanks
br.
Miroslav Stanik