Hi Team, I have recently upgraded one of my server from Centos7.9 to Rocky 9.4. After upgrading the server, I get the below error if I try to ssh to the server from another CentOS 7.9 server. Unable to negotiate with xxx.xxx.xxx.xx port 22: no matching host key type found. Their offer: ssh-rsa,ss…

If you look at sshd.service in Rocky 9 – with: cat /usr/lib/systemd/system/sshd.service you should see that the service wants sshd-keygen.target and that in turn: Wants=sshd-keygen@rsa.service Wants=sshd-keygen@ecdsa.service Wants=sshd-keygen@ed25519.service In other words, the Rocky 9 system sh…

[image] scotts: upgraded one of my server from Centos7.9 to Rocky 9.4 One more thing: I do hope that by “upgrade” you do mean fresh install of Rocky 9, and not any dark magick.

One more thing to consider would be the key length of the RSA pubkey. I have seen servers reject if it wasn’t 2048 or higher. Perhaps it’s an old generated ssh-key that is too short?

I missed conectiva for its distro upgrade - and downgrade - versatility, just with apt4rpm (another best-of-breed over DidNotFinish). Wow, did that work a treat.

[image] iwalker: One more thing to consider would be the key length of the RSA pubkey. I have seen servers reject if it wasn’t 2048 or higher. Perhaps it’s an old generated ssh-key that is too short? That is quite true. Alas, the error message would be different: [me@el9 ~]$ ssh old-server-w…

Are you sure you have an RSA key and that’s what you’re actually sending? From the server message, it clearly says it accepts RSA. Why don’t you just generate a new RSA key with ssh-keygen -t rsa and try that? On some systems, it defaults to Ed25519 so you need to explicitly set it to RSA. What is …

Ssh-rsa key algorithm not accepted in Rocky 9.4

Rocky Linux Help & Support

jlehtone November 5, 2024, 12:11pm 3

One more thing:
I do hope that by “upgrade” you do mean fresh install of Rocky 9, and not any dark magick.

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Ssh-rsa key algorithm not accepted in Rocky 9.4

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