I just installed Ubuntu 22.04 on my desktop computer and now the Android app AndFTP on my phone gives the error
There was a problem while connecting to 192.168.178.52:22 java.IOException
Key exchange was not finished, connection is closed.
when I try to login using SSH with a keypair, even before I entered the password of the keypair.
When I try ssh [email protected] on the desktop itself it works just fine.
What am I doing wrong?
It seems to me that 22.04 has reviewed a lot of security and enforced a lot of changes to the previous defaults. From what I can tell, ED25519 is deemed to be significantly better than RSA, which has been disabled by default.
If you uncomment "HostKey /etc/ssh/ssh_host_ed25519_key" in /etc/ssh/sshd_config and restart the server with "sudo service sshd restart". You can now connect this way without enabling the "lesser" RSA method.
In AndFTP, you can go to "Edit connection" > "Advanced" > "Expert/Specific FTP settings" > "SSH provider" and switch to the "Secure" mode, which works for me.