Uncommenting AuthorizedKeysFile in sshd_config causes public key authentication to fail

These days, it looks like I am making a habit of forgetting the most elementary things: For example, just a few days ago, I accidentally locked my car keys in the trunk of the car with the nearest set of spares almost 250 miles away. Way to go, Genius!

So, I was not too surprised to see that I was locked out of my Linode following another pacman -Syu. Mind you, I thought I had carefully reviewed every single update this time.

Public key authentication was not working. And since I had disabled password logins, I was not able to log on.

A quick Google search got me a relevant message in the mailing list archives.

It looked like the way sshd handles the AuthorizedKeysFile entry in sshd_config had changed in the new version. The path specified used to be assumed to be relative to the user’s home directory. Now, if, like me, you had commented out that line, it had to specify an absolute path. A further search of the ArchLinux bug database gave me FS#18781 which confirmed this diagnosis and confirmed the solution.

The only question was how to apply the fix. Well, that is where Linode’s lish came through with flying colors. It allowed me to get console access to my virtual server, fix the AuthorizedKeysFile entry in sshd_config. After doing a quick /etc/rc.d/sshd restart, I was able to log in to my virtual server using PuTTY and Pageant.


Update 2013/04/16: My praise for Linode is on hold for now, see Linode disappoints for more information.

Update 2013/05/28: I decided to stay with Linode after some consideration.