Celestial Software

I've been trying out old versions of OpenSSH to try to reproduce this bug. I've tried 2.3.0p1, which worked just fine. Then, 2.1.1p4 which I couldn't even log in. If you can get me access to your server, I may be able to diagnose this, but I haven't been able to reproduce this problem here. Really, I'm not sure it's much use trying to debug, as newer versions of the ssh server do not exhibit this problem. I'd be willing to give it a try, though.

Brian Pence
Celestial Software

Thanks to PEGLabs in the final diagnosis of this!!!

The problem is indeed a bug in older versions of OpenSSH triggered by a new feature of AbsoluteTelnet!

According to the SSH documentation, new encryption keys should be generated after every gigabyte of data or after 1 hour elapsed time, whichever comes first. AbsoluteTelnet v3.00 attempts to renegotiate new keys after one hour of connect time, and this throws older OpenSSH servers for a loop!! Newer servers are more compliant and expect the negotiation to occur, so no problems there.

For now, I've created a new beta that disables the key re-negotiation entirely. Most likely, I'll make it optional in the production release of 3.11, but the default will be OFF.

You can download the beta here:

http://www.celestialsoftware.net/telnet/beta_software.html