So once in a while I’ll run into a problem where I can log into a server via SSH as one user via public key, and taking the authorized_keys keys and dumping it into another user’s .ssh/ folder doesn’t work.

There are a few things you can try.

Permissions

Try this:

chmod 0700 .ssh/
chmod 0600 .ssh/authorized_keys
sudo chown -R myuser:mygroup .ssh/

That should fix it 99% of the time.

Locked account

Tonight I had an issue where the permissions were all perfect…checked, double checked, and yes they were fine.

So after poking at it for an hour (instead of smartly checking the logs) I decided to check the logs. I saw this error:

Nov 23 05:26:46 localhost sshd[1146]: User deploy not allowed because account is locked
Nov 23 05:26:46 localhost sshd[1146]: input_userauth_request: invalid user deploy [preauth]

Huh? I looked it up, and apparently an account can become locked if its password is too short or insecure. So I did

sudo passwd deploy

Changed the password to something longer, and it worked!

Have any more tips on fixing SSH login issues? Let us know in the comments below.