So I’ve set up SSH passwordless login a hundred times, but I’ve never run into a problem like this. I have an Ubuntu server that has your standard sshd server installation. I’ve verified the permissions on my home folder, my .ssh folder, and my authorized_keys file. I have the correct key in authorized_keys and I’ve got Pageant running with my private key loaded into it on my Windows client. Everything is set up and was working fine up until today.
Today, I tried to log in and I got prompted for a password. So I messed around with settings, restarted the SSH service, and tried a few other things. When that didn’t work, I just set things back to the way they were and tried again. I logged into one PuTTY SSH session using my password, then for kicks and giggles opened up another PuTTY window and tried to log in again. This time, it logged me in without a prompt using just my RSA key. I have the same result no matter what program I use. PuTTY, WinSCP, TortoisePlink, you name it. The second session will only work with the keys if I leave the first session open. In other words, if I close the first window that I logged into with my password, I can no longer log in with my keys for sequential sessions.
Am I missing something blatantly obvious?
Seems like your home directory encrypted. First login decrypts the contents & the second SSH is keyless because the SSH key can now be read. Check out the discussion here.