[vox-tech] SSH Troubles

[Marc Elliot Hall]

Today I've been trying to connect to my SSH server, and although I can
connect using SSH via my LAN, when I attempt to connect from my work 
machine, or even while I'm at home through my VLAN, the connection 
fails.

Generally I use PuTTY (Release 0.58) for this with no problems. Today, 
though, the connection fails and PuTTY says:

"Server's host key did not match the signature supplied"

A Google search reveals this page:

http://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/host-key-sig-verify-fail.html

which describes it as a difficult-to-reproduce bug, although it is still
unclear whether the bug is in PuTTY or in the SSH server.

So I thought, "okay, if it's possibly a PuTTY problem. I'll try a
different SSH client." After installing SecureCRT (Version 4.1.9 (build
278)) and attempting to connect, SecureCRT says:

"The server's host key failed to verify."

Googling on that phrase generates a single PDF link, which simply
recommends that one should use PuTTY, completely failing to adequately
address the issue.

Not one to give up easily, I then used the Cygwin SSH client to attempt
a connection. (Cygwin OpenSSH_4.3p2, OpenSSL 0.9.8a 11 Oct 2005)

Cygwin says:

$ ssh -p21 me at mydomain.com
RSA_public_decrypt failed: error:0407006A:rsa
routines:RSA_padding_check_PKCS1_type_1:block type is not 01
key_verify failed for server_host_key

I have restarted the ssh daemon as well as my Netgear firewall/router 
appliance, and get the same results. 

Since I routinely apt-get update my Debian Testing server, including
yesterday, I suspect this issue may be related to a recent change in
sshd. I also rebooted the machine yesterday due to an updated kernel. 

Linux 2.6.15-1-686
OpenSSH_4.3p2 Debian-2, OpenSSL 0.9.8b

Any ideas?


-- 
Marc Elliot Hall
www.hallmarc.net