ssh Issues (Algorithm negotiation fail)

[Former user]

I was messing around with Virutal Machines today (Bridged Network Connection) and 1.5.1001 was giving me issues with connecting over ssh. It didn't work on Ubuntu 16.04 (VM) or on Fedora 23 (PM) but it did work on Ubuntu 14.04. It gives me the error "Algorithm negotiation fail"

[Anton Demidov]

Add the following lines at the end of the file /etc/ssh/sshd_config

Ciphers aes128-cbc,aes192-cbc,aes256-cbc,blowfish-cbc,arcfour
KexAlgorithms diffie-hellman-group1-sha1

And restart ssh service after that sudo /etc/init.d/ssh restart

The solution was taken from https://bugzilla.redhat.com/show_bug.cgi?id=1228013#c13 and it works for me on Ubuntu 16.04.

There is SharpSSH library is used for SSH tunneling in Yulli, which is .NET port of original Java library JSch.

The default set of ciphers has been altered in Ubuntu 16.04 to remove potentially unsafe algorithms. It seems the new encryption algorithms were added in the latest JSch, but SharpSSH is slightly outdated.

This is only a temporary solution. Use it at your own risk and only if you know what consequences it may entail.

[Adam Hellberg]

Should this really be marked as resolved? Allowing unsafe algorithms is a workaround, not a fix, and telling users to just blanket enable it on their servers seems very bad. Unsafe algorithms are removed for a reason.