[Dovecot] odd pam_authenticate() failed: authentication error followed by successful imap-login

[Sahil Tandon]

I am seeing the following errors in my log:

Jul 27 18:14:23 aegis dovecot: auth-worker(default_with_listener): 
pam(user at host.org,74.72.46.170): pam_authenticate() failed: authentication 
error
Jul 27 18:14:23 aegis dovecot: imap-login: Login: user=<user at host.org>, 
method=PLAIN, rip=74.72.46.170, lip=206.251.255.39, TLS                       
       
This happens *only* for virtual users; local UNIX users authenticate without 
that first error.  However, all users are able to view mail, but that 
default_with_listener (which I setup just so Postfix could use dovecot to 
authenticate SASL senders) error only occurs for virtual users.  Why is 
default_with_listener getting involved when users are trying to connect to 
dovecot directly without any involvement of Postfix?  Non-default 
configuration parameters below; thanks for any hints.

# dovecot -n
# 1.1.1: /usr/local/etc/dovecot.conf
listen: 127.0.0.1:143
ssl_listen: *:993
login_dir: /var/run/dovecot/login
login_executable: /usr/local/libexec/dovecot/imap-login
verbose_proctitle: yes
first_valid_gid: 0
mail_privileged_group: mail
mail_location: maildir:~/Maildir
imap_client_workarounds: delay-newmail outlook-idle netscape-eoh 
tb-extra-mailbox-sep
auth default_with_listener:
  mechanisms: plain login digest-md5
  passdb:
    driver: pam
  passdb:
    driver: passwd-file
    args: /usr/local/etc/dovecot/passwd
  userdb:
    driver: passwd
  userdb:
    driver: passwd-file
    args: /usr/local/etc/dovecot/users
  socket:
    type: listen
    client:
      path: /var/spool/postfix/private/auth
      mode: 432
      user: postfix
      group: postfix
auth default:
  mechanisms: plain digest-md5
  passdb:
    driver: passwd-file
    args: /usr/local/etc/dovecot/passwd
  passdb:
    driver: pam
  userdb:
    driver: passwd-file
    args: /usr/local/etc/dovecot/users
  userdb:
    driver: passwd

-- 
Sahil Tandon <sahil at tandon.net>