The official AlmaLinux OS 9 (x86_64) AMI - Server refused our key

Question

I have no problems creating a VM from the officially provided AlmaLinux OS 8. I can create the image and use my key to ssh. However, there seems to be something wrong with the official AlmaLinux OS 9 (x86_64) AMI. Since I am using the same key for both attempts, I am sure that there is nothing wrong with the key, but the Alma 9 image always refuses. I am using the username as specified in the description of the AMI - ec2-user.

Can someone confirm that there is something wrong with the image, or a workaround to ssh to the box?

Accepted Answer

This sounds like it could be a cipher mis-match, how old is the key that you're using to connect, and/or how old is the SSH client that you're using (e.g. PuTTY)?

Simplifying things **a lot**, some encryption algorithms that used to be considered to be secure, are now no longer thought of in that way, and are deprecated in the newest releases of the various flavours of Linux.

Are you able to update the SSH client and/or generate a new key that uses a more secure cipher, and see if that works, though I appreciate this means having to spin up a fresh Alma Linux 9 EC2? (actually, you can update the SSH key in-place using User Data but as a solution to your problem it's probably more trouble than it's worth https://repost.aws/knowledge-center/user-data-replace-key-pair-ec2 )

Answer

Embarrassingly enough, it was the ssh client that I was using.  I used a newer client and I was able to connect.  What really threw me off was when I tried to connect in the AWS UI on the instance page via the "connect" button, and it also failed.  Maybe that UI was just not supported with that OS.  Thanks.

The official AlmaLinux OS 9 (x86_64) AMI - Server refused our key

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