pam_unix should not always complain about failed authentication

[Kjell Braden]

I run a server with ubuntu lucid, pam et al 1.1.1-2ubuntu5.3.
I used pam-auth-update to enable unix-style and ldap style authentication.
For accounts that exist in my LDAP only, i get on every (successful!) authentication attempt the following message in auth.log:

dovecot-auth: pam_unix(dovecot:auth): authentication failure; logname= uid=0 euid=0 tty=dovecot ruser=xyz rhost=127.0.0.1 user=xyz

This appears to happen because of any of the following problems:
1. the unix module has a higher priority than the ldap module
2. the unix module itself logs errors even if its "control" settings (ie. the second field in common-auth) ask it to ignore such a problem
3. the unix module is not supposed to be configured at the same time as the ldap module.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[jlacy86 (jlacy86)]

I am also experiencing this problem on oneiric, Ubuntu 11.

[John Python (python-noob)]

This problem also exists for sssd:

Sep 25 13:11:10 myserver sshd[15919]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=127.0.0.1 user=bob
Sep 25 13:11:10 myserver sshd[15919]: pam_sss(sshd:auth): authentication success; logname= uid=0 euid=0 tty=ssh ruser= rhost=127.0.0.1 user=bob

It's possible to fix this ourselves, but it would be much better to see a more permanent solution.