[Dovecot] Stalled Authentication, Great Clues

[Richard Petty]

I've just installed Dovecot 0.99.12.1 onto a White Box EL 3 server. I'm 
mostly following the email server setup instructions at 
http://www.wanderingbarque.com/mailserver.html and getting Dovecot to 
work is the last task to complete.

I've compiled Dovecot with LDAP support. I'm authenticating Postfix via 
SASL to the LDAP database just fine, and I also authenticate and 
manipulate LDAP info from JAMM very well, too. However, Dovecot 
authentication seem to hang up when a correct password is submitted (POP 
or IMAP... it doesn't matter).

Here's an example of the problem:

  [root at kayak /etc] telnet localhost 110
  Trying 127.0.0.1...
  Connected to localhost.bramble.com (127.0.0.1).
  Escape character is '^]'.
  +OK dovecot ready.
  user repetty at bizzy.mine.nu
  +OK
  pass bogeybogey

  sadf
  hello?
  ^]

  telnet> q
  Connection closed.


As you can see, once I hit the return key to submit the password I do 
not get another prompt. In fact, Dovecot doesn't respond at all although 
it seems to respond to the escape character just fine.

Additionally, dovecot-auth starts soaking up CPU time... until I kill 
the process (dovecot-auth must be killed manually.)

   22:15:32  up 32 days, 21:40,  5 users,  load average: 1.05, 1.02, 0.98
  121 processes: 119 sleeping, 2 running, 0 zombie, 0 stopped
  CPU states:  cpu    user    nice  system    irq  softirq  iowait    idle
             total   50.5%    0.0%    0.5%   0.0%     0.0%    0.0%   48.8%
             cpu00   66.7%    0.0%    0.0%   0.0%     0.0%    0.0%   33.2%
             cpu01   34.4%    0.0%    1.1%   0.0%     0.0%    0.0%   64.3%
  Mem:   318260k av,  300740k used,   17520k free,       0k shrd,   
24380k buff
                      141540k actv,   28364k in_d,    3864k in_c
  Swap:  655352k av,   80868k used,  574484k free                   
94736k cached

    PID USER     PRI  NI  SIZE  RSS SHARE STAT %CPU %MEM   TIME CPU COMMAND
  23846 dovecot   25   0  1928 1928  1352 R    49.7  0.6  27:30   0 
dovecot-auth
  23847 dovecot   15   0  1072 1072   868 S     0.0  0.3   0:00   1 
imap-login
  23848 dovecot   15   0  1072 1072   868 S     0.0  0.3   0:00   1 
imap-login
  23849 dovecot   15   0  1160 1160   936 S     0.0  0.3   0:00   1 
imap-login
  23850 dovecot   15   0  1136 1136   928 S     0.0  0.3   0:00   0 
pop3-login
  23851 dovecot   15   0  1140 1140   928 S     0.0  0.3   0:00   1 
pop3-login
  23852 dovecot   15   0  1140 1140   928 S     0.0  0.3   0:00   0 
pop3-login
  23858 dovecot   15   0  1068 1068   868 S     0.0  0.3   0:00   0 
imap-login
  23870 dovecot   15   0  1064 1064   864 S     0.0  0.3   0:00   1 
pop3-login
  23886 dovecot   15   0  1060 1060   864 S     0.0  0.3   0:00   1 
pop3-login
  23916 dovecot   15   0  1064 1064   864 S     0.0  0.3   0:00   0 
pop3-login


 From the client's point of view, the server never seems to come back 
after the account password is submitted. Dovecot's log shows that it 
eventually times out the client, although the client never seems to get 
wind of this:

  pop3-login: Dec 19 22:13:08 Info: Disconnected: Inactivity [192.168.0.6]


I know that Dovecot is connecting to the LDAP server because if I mess 
up the Dovecot LDAP password in the dovecot.conf file I get an 
authentication error (as I should):

  dovecot-auth: Dec 19 20:52:19 Error: LDAP: ldap_simple_bind_s()
    failed (dn cn=dovecot,dc=dillo,dc=info): Invalid credentials


Again, if client submits an incorrect email account password everything 
works as it should: Dovecot tells the client that the password is 
incorrect, over and over, if necessary. However, if the password is 
entered correctly then Dovecot hangs up for good.


--Richard