I reported this a month or two back as well but got no responses. It happens for us when the user enters an incorrect password.

I am using "auth_bind = yes" in my config and summized that the ldap code in dovecot may be caching the previous user's credentials for use in subsequent bind lookups instead of using the credentials specified by dn / dnpass. That would explain why a failed authentication might result in all subsequent ldap_search() calls failing.

Our production server is currently running dovecot-1.0-0.beta8.2.fc5 from the Fedora 5 distribution, but I have tested that the problem still exists up to the rc9 release. I have not tried it with rc10 yet.

These are the typical messages I get in the logs:

Oct 22 09:50:35 gm-ho-lin-06 dovecot: auth(default): client in: AUTH    1       PLAIN   service=POP3    lip=::ffff:10.1.101.10 rip=::ffff:10.0.25.193 resp=
Oct 22 09:50:35 gm-ho-lin-06 dovecot: auth(default): client out: CONT   1
Oct 22 09:50:35 gm-ho-lin-06 dovecot: auth(default): client in: CONT    1       ADAyMDdAc3RvcmVzLmdhbWUuY28udWsAMDcwMg==
Oct 22 09:50:35 gm-ho-lin-06 dovecot: auth(default): ldap(0207@stores.game.co.uk,::ffff:10.0.25.193): bind search: base=OU=Stores,OU=UK,DC=group,DC=game,DC=net filter=(&(objectClass=user)(mail=0207@stores.game.co.uk))
Oct 22 09:50:36 gm-ho-lin-06 dovecot: auth(default): client out: FAIL   1       user=0207@stores.game.co.uk
Oct 22 09:50:36 gm-ho-lin-06 dovecot: auth(default): client in: AUTH    2       PLAIN   service=POP3    lip=::ffff:10.1.101.10 rip=::ffff:10.0.25.193 resp=ADAyMDdAc3RvcmVzLmdhbWUuY28udWsAMDcwMg==
Oct 22 09:50:36 gm-ho-lin-06 dovecot: auth(default): ldap(0207@stores.game.co.uk,::ffff:10.0.25.193): bind search: base=OU=Stores,OU=UK,DC=group,DC=game,DC=net filter=(&(objectClass=user)(mail=0207@stores.game.co.uk))
Oct 22 09:50:36 gm-ho-lin-06 dovecot: auth(default): ldap(0207@stores.game.co.uk,::ffff:10.0.25.193): ldap_search() failed: Operations error
Oct 22 09:50:38 gm-ho-lin-06 dovecot: auth(default): client in: AUTH    1       PLAIN   service=POP3    lip=::ffff:10.1.101.10 rip=::ffff:10.0.70.193 resp=
Oct 22 09:50:38 gm-ho-lin-06 dovecot: auth(default): client out: CONT   1
Oct 22 09:50:38 gm-ho-lin-06 dovecot: auth(default): client in: CONT    1       ADA1NjdAc3RvcmVzLmdhbWUuY28udWsANzY1MA==
Oct 22 09:50:38 gm-ho-lin-06 dovecot: auth(default): ldap(0567@stores.game.co.uk,::ffff:10.0.70.193): bind search: base=OU=Stores,OU=UK,DC=group,DC=game,DC=net filter=(&(objectClass=user)(mail=0567@stores.game.co.uk))
Oct 22 09:50:38 gm-ho-lin-06 dovecot: auth(default): ldap(0567@stores.game.co.uk,::ffff:10.0.70.193): ldap_search() failed: Operations error
Oct 22 09:50:38 gm-ho-lin-06 dovecot: auth(default): client out: FAIL   2       user=0207@stores.game.co.uk     temp
Oct 22 09:50:38 gm-ho-lin-06 dovecot: auth(default): client out: FAIL   1       user=0567@stores.game.co.uk     temp
Oct 22 09:50:38 gm-ho-lin-06 dovecot: auth(default): client in: AUTH    2       PLAIN   service=POP3    lip=::ffff:10.1.101.10 rip=::ffff:10.0.70.193 resp=ADA1NjdAc3RvcmVzLmdhbWUuY28udWsANzY1MA==
Oct 22 09:50:38 gm-ho-lin-06 dovecot: auth(default): ldap(0567@stores.game.co.uk,::ffff:10.0.70.193): bind search: base=OU=Stores,OU=UK,DC=group,DC=game,DC=net filter=(&(objectClass=user)(mail=0567@stores.game.co.uk))
Oct 22 09:50:38 gm-ho-lin-06 dovecot: auth(default): ldap(0567@stores.game.co.uk,::ffff:10.0.70.193): ldap_search() failed: Operations error
Oct 22 09:50:40 gm-ho-lin-06 dovecot: auth(default): client out: FAIL   2       user=0567@stores.game.co.uk     temp

Regards,
Rob Coward

On Tue, 2006-10-24 at 14:28 +0300, Timo Sirainen wrote:

On Mon, 2006-10-23 at 12:07 -0200, Matheus Antonio Oliveira wrote:
> People,
> 
> I have a situation: when use a passwd LDAP module against "microsoft 
> active directory" and one user send a blank password the authentication 
> module returns: "ERR [IN-USE] Internal login failure. Refer to server 
> log for more information."; after this the authentication module never 
> authenticate again "ERR Temporary authentication failure."
..
> -ERR [IN-USE] Internal login failure. Refer to server log for more 
> information.

Could you also show what error message it wrote to the log file?

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