Server Refused our Key after upgrading to Ubuntu v22

Question

I upgraded our webserver to Ubuntu v22 and am now unable to login via Putty after restart, it says "Server Refused our Key," and a prompt "Disconnected: No supported authentication methods available (Server sent: publickey)." It was working fine before this.

I can still login using the same private key using FileZilla / SFTP.

After the restart the server did not start my webserver and the website is down, so any help you can provide I will be grateful.

Does this answer your question? Ubuntu 22.04 SSH the RSA key isn't working since upgrading from 20.04 — user68186, Nov 18 '22 at 22:58
Yes, I am using RSA Key. I have read this, but my server is on Lightsail, and how can I change the key, when I have no access to putty? — Waqas Tariq, Nov 18 '22 at 23:01
Hahaha...Unfortunately, I can't do that as it's with Amazon. I will use my backup that I created, and boot a new instance. Thank you for your time. — Waqas Tariq, Nov 18 '22 at 23:08
Can you provide a solution here, as to what I need to do before upgrading my instance again? — Waqas Tariq, Nov 18 '22 at 23:10
AWS has it's portal that allows access to the VM hosted there. Spin up the new instance from backup of the 20.04 server. Create a new public private key pair as described in the linked answer. Send the new public key to the server. Move the old private key to a different location. Test if you can ssh using the new key pair. Upgrade server to 22.04 and test again. Rinse and repeat. — user68186, Nov 18 '22 at 23:16

score 5 · Answer 1 · answered Mar 13 '23 at 02:21

5

I upgrade my digitalocean droplet from ubuntu 18.04 to 20.04 to 22.04. There is no problem on my putty ssh at 20.04. but "refused our key" when I upgraded to 22.04.

I fix the problem after update my putty from 0.74 to 0.78.

https://www.systemtek.co.uk/2019/03/how-to-update-putty/

hope this could help.

answered Mar 13 '23 at 02:21

franman726

51

1

I was also having trouble connecting to an Ubuntu 22.04, and upgrading putty worked – lucasvw Apr 07 '23 at 19:35
Funny, I went through the exact same process and had the exact same versions as you. Your fix worked. I also followed your link, I did not get a pop-up asking my to keep my Putty data, but it still saved it when 0.79 got installed. – busytraining Aug 31 '23 at 02:48

score 2 · Answer 2 · answered Nov 18 '22 at 23:34

2

I created an ED25519 key, and then used FileZilla to access /home/ubuntu/.ssh to replace the key and change file permission to 600. This gave me access to the server

answered Nov 18 '22 at 23:34

Waqas Tariq

1,013

score 0 · Answer 3 · answered Feb 01 '23 at 21:10

I ran into the same issues with Ubuntu Mate 20.04 to 22.04 upgrade. Every time I tried to access the server through SSH I keep getting "key is refused". I could still access the server with WinSCP.

I was able to fix the issue by just upgrading Kitty (a fork of Putty).

So for anyone else that runs into this issue in the future, first try upgrading your SSH Client.

Server Refused our Key after upgrading to Ubuntu v22

3 Answers3