Trying to connect to an SFTP server. The server in question is a very vanilla Ubuntu 22.04 VPS running on Digital Ocean (using Laravel Forge).
Am able to connect via SSH fine, and via WinSCP and Putty, using the same username and private key. Opus just won't seem to do it for some reason.
This is the Opus SFTP (debug) log with a few key details taken out:
Opening Connection XXX.64.166.XXX:22
Server version: SSH-2.0-OpenSSH_8.9p1 Ubuntu-3ubuntu0.1
Using SSH protocol version 2
We claim version: SSH-2.0-PuTTY_Directory_Opus
Server supports delayed compression; will try this later
Doing ECDH key exchange with curve Curve25519 and hash SHA-256
Server also has ecdsa-sha2-nistp256 host key, but we don't know it
Host key fingerprint is:
ssh-ed25519 256 XX:XX:c6:ad:99:f8:6a:c8:90:ed:28:1d:9e:b4:a1:XX
Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Reading key file "C:\SSH\Keys\Private.ppk"
Using username "xxxx".
Offered public key
Server refused our key
Server refused our key
Disconnected: No supported authentication methods available (server sent: publickey)
SSH: Fatal: Disconnected: No supported authentication methods available (server sent: publickey)
Connection closed
Ok, I can do that - and given I have been using ssh-rsa with all my other servers (on older Ubuntus), I am not super worried about it. But also fair to say that it's been heading towards a year and it would be nice to see Opus being bit more up to date/responsive here. (Especially given the SFTP thing is an extra paid addon, I think it's fair to expect it to stay quite current with the sort of servers it's likely to connect to - with Ubuntu LTS being pretty much #1 on that list...)
Any idea when this might be happening...in the meantime Ubuntu 24.04 has come along, and of course has the same issue.
Server version: SSH-2.0-OpenSSH_8.9p1 Ubuntu-3ubuntu0.7 Using SSH protocol version 2 We claim version: SSH-2.0-PuTTY_Directory_Opus Server supports delayed compression; will try this later Doing ECDH key exchange with curve Curve25519 and hash SHA-256 Server also has ecdsa-sha2-nistp256 host key, but we don't know it Host key fingerprint is: ssh-ed25519 blah Initialised AES-256 SDCTR client->server encryption Initialised HMAC-SHA-256 client->server MAC algorithm Initialised AES-256 SDCTR server->client encryption
Given RSA is at this point pretty much a broken thing and probably not long for the SSH world, new key type support is becoming yet more pressing.
I don't have an ETA yet, sorry. Part of the problem is there are no good SFTP libraries in existence. They're all incredibly slow (even by SFTP standards), which isn't good enough, and the couple of apps that are reasonably fast don't have reusable code, so we're having to do a lot more than expected to do this properly.
Ok, well, I guess WinSCP it is, for a while, then - I'm no longer feeling comfortable about opening servers to accept RSA at this point really, and have moved literally everything else SSH/SFTP over to ed25519.
Thanks for the answer and good luck with the work.