With macOS High Sierra 10.13.4, I understand they have changed the key length for SSH.
Is it possible to change anything with ssh config to allow lower key length? I cannot recreate a longer key length from a specific server (old APC UPS).
macOS High Sierra (10.13.4)
Hold on a second. When did you create your "SSH user Host Key File"? I think it may be your old key file from your Mac that you've uploaded to the APC.
See this thread for more details: https://discussions.apple.com/thread/8203610
Have you tried to create a key on the Mac that conforms to those requirements? Use the "-b" parameter in ssh-keygen. Make sure to save the output to a dedicated key. You don't want to overwrite any other keys.
Hello xSouljahx,
Can you provide some more context? What command are you trying? High Sierra may have changed some defaults. Apple does that every year. But you should be able to change settings in the config file or on the command line if you have specific needs.
Hi etresoft,
When I try to SSH to an APC UPS that cannot regenerate a longer host key, it fails with message: ssh_dispatch_run_fatal: Connection to X.X.X.X port 22: Invalid key length.
Here are the options in APC. I've already deleted host key and regenerated a new one on the APC but it doesn't have options to make it longer. So I'm curious if there's anything I can do on the Mac/SSH side as I'm assuming the new default is 2048.
I did see that thread. Although I do not know the answer to your question, but please correct me if I'm understanding wrong.
The workaround was to recreate the SSH on the server with a larger bit. The APC automatically does this when I delete the host key, it regenerates a new one but it is most likely a smaller one - there is no option.
I just don't know if it is talking about the remote host or the public/private key on the local machine that you have uploaded to the remote host. Can you use the same public/private key to connect to other services?
No, would you be so kind to show me an example?
ssh_dispatch_run_fatal: Invalid key length
