PAM auth error with empty passphrase over SSH
 

hi everybody

have a weird problem between two of my hosts. Basically the setup is that I have one host (A) rsyncing some directories to another host (B) via SSH, using an empty passphrase to avoid an interactive logon.

It all works fine, I've setup a similar thing across about 60 other boxes, however in A's auth logs I get one of these lines whenever B logs in :

Sep 13 12:02:29 XXXX PAM_unix[29273]: authentication failure; (uid=0) -> XXXX for ssh service
Sep 13 12:02:31 XXXX sshd[29273]: Accepted publickey for XXXX from XXXX port 3228 ssh2

Seems strange that it would be rejecting the password and yet simultaneously allowing the login with a passphrase ... It's even more annoying as logcheck emails me every single time about it, and the process runs every 180 seconds. I could add a regex to logcheck to ignore it of course, but it doesn't fix the core issue.

also, to clarify I still need to login remotely with my normal username/password, so turning off PasswordAuthentication isn't really an option.

I also set PermitEmptyPasswords to yes for 'shits'n'giggles', but same problem.

any ideas? any pointers hugely appreciated :)