Ssh: handshake failed

I am running the GUI version of duplicacy and trying to add storage (remote synology NAS) over SFTP.

I have created a certificate that I have on the synology and the same one on my machine. The passphrase is correct, because it cries when I have misspelled it.

I get this error while trying to select a Directory:

Failed to create the sftp client: ssh: handshake failed: ssh: unable to authenticate, attempted methods [none publickey], no supported methods remain

Can someone more skilled than me explain to me what am I doing wrong ? Or at least direct me towards what I could try ?


Are you trying to log in using a certificate? This is not supported. Only a private key file can be used.

I have created a SSH key with a passphrase …
Apologies for using a wrong terminology.

You can test the key with ssh in a terminal like this:

ssh -i <key_file> user@server

What is the type of your key, as indicated by the first line of the key file?

You can also look at the log file ~/.duplicacy-web/logs/duplicacy_web.log which may contain more detailed error messages.

Does this " attempted methods [none publickey] " mean that I have an invalid key ?
I followed this tut : How to set up SSH Keys with your Synology NAS (+macOS) | 4K TUTORIAL - YouTube

with the exception of adding a passphrase …

Likely. Again, the best way to figure it out is to run ssh -i key from the command line to verify that the key actually works.

The terminal command ssh’ed me to the Synology successfully (but only on the local LAN). Remote connection via public IP does not work with a port specified.

The log file does not show more than the error message specified above.