Note: I recently purchased a Synology DiskStation DS411j & I’m putting up posts about things I figure out. This is part of that series.
In a previous post—SSH into your Synology DiskStation with SSH Keys—I covered how to log in to your DiskStation using SSH keys instead of a password. After you know your keys work, it’s a good idea to configure the SSH daemon on the DiskStation to disallow passwords so you only log in via keys. This adds a nice layer of security, but it also means that you’d better keep backups of your SSH keys, or you are hosed! If you’re ready to do it, edit
/etc/ssh/sshd_config & change these lines:
Save the file & restart the SSH daemon. Theoretically, you can do this on the command line—
/usr/syno/etc.defaults/rc.d/S95sshd.sh restart—but I’ve found that this doesn’t always work, which is troubling. Instead, use the GUI. Click on the Control Panel on the “Desktop” of the DiskStation, & then click on Terminal. Uncheck Enable SSH Service, check it again, and press OK.
Try logging in now, but use a username that doesn’t exist on the server. You won’t be prompted for a password; instead, you’ll see:
No key, no admittance. No passwords accepted. Excellent.