[JSch-users] OpenSSH Server with aes192-ctr and aes256-ctr only

[Matt Tucker]

Hi JSch Users,

I apologize if this was sent twice, I didn't see it updated in the mailing
list archives.

I'm trying to investigate an issue in an application that uses the JSch
library to connect to remote SSH servers.

Using the default configuration on OpenSSH, everything works great. By
modifying the /etc/ssh/sshd_config file (adding "Ciphers
aes192-ctr,aes256-ctr") and restarting the ssh service, JSch no longer is
able to connect, throwing an "Algorithm negotiation fail" exception.
Connecting via the SSH client in Ubuntu, I'm still able to connect
successfully, so I do not believe this to be an issue with the OpenSSH
server configuration.

My testing of this issue has been using the Logger.java example
<http://www.jcraft.com/jsch/examples/Logger.java.html> on the JSch
website. In looking at the output, it appears that the aes192-ctr and
aes256-ctr ciphers are not listed. These ciphers appear to be supported
according to the JSch website.

Are there additional configuration settings needed in order to enable these
Cipher options?

Server:
Virtualbox 4.3.18
Ubuntu 14.04.2
OpenSSH_6.6.1p1 Ubuntu-2ubuntu2, OpenSSL 1.0.1f 6 Jan 2014

Client:
Windows 7
Java 7u76 with JCE Unlimited Encryption
JSCH 0.1.51

Thank you,