Problems with kio sftp in Dolphin/Konqueror

Solution 1:

This is a known issue with Dolphin and ECDSA keys. OpenSSH in recent versions have moved to use ECDSA by default over RSA, and this works fine with most implementations that rely on OpenSSH's "known hosts" file.

Dolphin's kio_sftp module uses libssh instead of OpenSSH's own libraries, and that library appears to not support ECDSA keys. The workaround is detailed in the KDE bug report - remove the existing key, and either force OpenSSH to cache the RSA host key (an example command line is detailed in the bug report and below), or just use Dolphin to connect directly.

Because the KDE bug is resolved, but we still see the bug in Kubuntu 15.04, I've opened a bug on the Kubuntu KDE implementation.

Sample command to reset the host key:

ssh-keygen -f "$HOME/.ssh/known_hosts" -R server
ssh -o HostKeyAlgorithms=ssh-rsa user@server

Solution 2:

As workaround you can use fish://yourserver instead of sftp and it'll work just great. Solution was taken from there: https://superuser.com/questions/299940/kubuntu-cant-add-new-ssh-network-folder