Dovecot Assertion on mail server with POP3 and LDAP authentication

[Tim Alberts]

Tim Alberts wrote:
> Running two Fedora 6 systems with all the latest updates as of a 
> couple days ago at least.  One system is the mail server (sendmail, 
> dovecot), the other is the master (open)LDAP server with the mail 
> server running a slave LDAP instance.
>
> The problem I'm having is the client pop3 users are frequently being 
> told their passwords aren't correct by their email clients (Outlook, 
> Eudora).  They try again, a couple times and eventually it works.  
> I've seen it on my own account and when I test their accounts, 
> occasionally it just doesn't take the password.  I've only had this 
> trouble since I implemented the LDAP authentication.
>
> Checking through the server maillog, I see the following entry:
>
> Apr  4 08:44:38 msi2 dovecot: auth(default): dovecot-auth: 
> ../../../libraries/liblber/io.c:491: ber_get_next: Assertion 
> `ber->ber_buf == ((void *)0)' failed.
> Apr  4 08:44:38 msi2 dovecot: auth(default): 
> pam(secretuser,192.168.0.200): Child process died
> Apr  4 08:44:38 msi2 dovecot: auth(default): PAM: Child 14564 died 
> with signal 6
> Apr  4 08:44:38 msi2 dovecot: pop3-login: Aborted login: 
> user=<secretuser>, method=PLAIN, rip=192.168.0.200, lip=192.168.0.11
>


I've been on the dovecot mailing list and after a couple days of running 
without errors, I believe I've found the problem.

The upgraded dovecot package mostly fixed the problem, but I also had to 
apply some configuration changes described at the following link:

http://wiki.dovecot.org/AuthDatabase/Passwd

So with the following version and configuration, I've got a stable 
program again.

[root at msi2 ~]# dovecot --version
1.0.rc28
[root at msi2 ~]# dovecot -n
# /etc/dovecot.conf
protocols: pop3
listen:
login_dir: /var/run/dovecot/login
login_executable: /usr/libexec/dovecot/pop3-login
mail_executable: /usr/libexec/dovecot/pop3
mail_plugin_dir: /usr/lib/dovecot/pop3
pop3_client_workarounds: outlook-no-nuls oe-ns-eoh
auth default:
  passdb:
    driver: pam
    args: dovecot
  userdb:
    driver: passwd
    args: blocking=yes
[root at msi2 ~]#