[Dovecot] dovecot/openldap auth problems?

[Lee]

Hi folks.  

New to both dovecot and openldap.  Trying to set up virtual domains
using the wanderingbarque howto:

http://www.wanderingbarque.com/mailserver.html

Platform is RH enterprise 3.

Only difference is I'm trying to use phamm instead of jamm:

http://phamm.rhx.it/

dovecot doesn't seem to want to play nice with my openldap; everything
else (postfix, etc) seems to work alright.  So I'm looking for some
hints as to what I'm doing wrong.  thanks in advance!

When I do an /sbin/service dovecot restart, here's the error from
/var/log/ldap.log:

<snip>
Dec 11 13:59:22 salcha slapd[15734]: => access_allowed: auth access to
"cn=dovecot,dc=akforecast" "u   serPassword" requested
Dec 11 13:59:22 salcha slapd[15734]: => dnpat: [1]
.*,jvd=([^,]+),o=hosting,dc=akforecast nsub: 1
Dec 11 13:59:22 salcha slapd[15734]: => dnpat: [2]
.*,jvd=([^,]+),o=hosting,dc=akforecast nsub: 1
Dec 11 13:59:22 salcha slapd[15734]: => dnpat: [3]
.*,jvd=([^,]+),o=hosting,dc=akforecast nsub: 1
Dec 11 13:59:22 salcha slapd[15734]: => dnpat: [4]
o=hosting,dc=akforecast nsub: 0
Dec 11 13:59:22 salcha slapd[15734]: => acl_get: [5] check attr
userPassword
Dec 11 13:59:22 salcha slapd[15734]: <= acl_get: [5] acl
cn=dovecot,dc=akforecast attr: userPassword
Dec 11 13:59:22 salcha slapd[15734]: => acl_mask: access to entry
"cn=dovecot,dc=akforecast", attr "   userPassword" requested
Dec 11 13:59:22 salcha slapd[15734]: => acl_mask: to all values by "",
(=n)
Dec 11 13:59:22 salcha slapd[15734]: <= check a_dn_pat: *
Dec 11 13:59:22 salcha slapd[15734]: <= acl_mask: [1] applying none (=n)
(stop)
Dec 11 13:59:22 salcha slapd[15734]: <= acl_mask: [1] mask: none (=n)
Dec 11 13:59:22 salcha slapd[15734]: => access_allowed: auth access
denied by none (=n)

Anyone see any big,glaring 'yewidiut' errors?  Or just hints as to what
could be wrong?

slapd.conf:
# $OpenLDAP: pkg/ldap/servers/slapd/slapd.conf,v 1.8.8.7 2001/09/27
20:00:31 kurt Exp $
#
# See slapd.conf(5) for details on configuration options.
# This file should NOT be world readable.
#
include         /etc/openldap/schema/core.schema
include         /etc/openldap/schema/cosine.schema
include         /etc/openldap/schema/inetorgperson.schema
include         /etc/openldap/schema/nis.schema
include         /etc/openldap/schema/redhat/autofs.schema
include         /etc/openldap/schema/redhat/kerberosobject.schema
# include         /etc/openldap/schema/jamm.schema
include         /etc/openldap/schema/phamm.schema
include         /etc/openldap/schema/ISPEnv2.schema
include         /etc/openldap/schema/amavisd-new.schema

password-hash {CRYPT}

# Define global ACLs to disable default read access.

# Do not enable referrals until AFTER you have a working directory
# service AND an understanding of referrals.
#referral       ldap://root.openldap.org

# Create a replication log in /var/lib/ldap for use by slurpd.
#replogfile     /var/lib/ldap/master-slapd.replog

schemacheck     on
pidfile         /var/run/openldap/slapd.pid
argsfile        /var/run/openldap/slapd.args
loglevel        128
lastmod         on

database        ldbm
directory       /var/lib/ldap
suffix          "dc=akforecast"
rootdn          "cn=manager,dc=akforecast"
rootpw          x

index   objectClass     eq
index   cn,mail         eq,subinitial

# include         /etc/openldap/slapd-phamm.acl

access to dn=".*,jvd=([^,]+),o=hosting,dc=akforecast" attr=userPassword
        by self write
        by
group/jammPostmaster/roleOccupant="cn=postmaster,jvd=$1,o=hosting,dc=akforecast" write
        by dn="cn=dovecot,dc=akforecast" read
        by anonymous auth
        by * none

access to dn=".*,jvd=([^,]+),o=hosting,dc=akforecast" attr=quota
        by
group/jammPostmaster/roleOccupant="cn=postmaster,jvd=$1,o=hosting,dc=akforecast" write
        by dn="cn=phamm,o=hosting,dc=akforecast" read
        by self read
        by * none

access to dn=".*,jvd=([^,]+),o=hosting,dc=akforecast"
        by self write
        by
group/jammPostmaster/roleOccupant="cn=postmaster,jvd=$1,o=hosting,dc=akforecast" write
        by dn="cn=phamm,o=hosting,dc=akforecast" read
        by * none

access to dn="o=hosting,dc=akforecast"
        by self write
        by dn="cn=phamm,o=hosting,dc=akforecast" read
        by anonymous auth
        by * none

access to *
        by * none


-----------------------------------------------------------

/etc/dovecot/dovecot-ldap.conf:

[root at salcha openldap]# cat /etc/dovecot/dovecot-ldap.conf
# NOTE: We don't support "authentication binds", so you'll have to give
# dovecot-auth read access to userPassword field in LDAP server. With
OpenLDAP
# this is done by modifying /etc/ldap/slapd.conf. There should already
be
# something like this:

# access to attribute=userPassword
#        by dn="<dovecot's dn>" read # add this
#        by anonymous auth
#        by self write
#        by * none

# Space separated list of LDAP hosts to use. host:port is allowed too.
#hosts = localhost
hosts = localhost

# Distinguished Name - the username used to login to the LDAP server
#dn =
dn = "cn=dovecot,dc=akforecast"

# Password for LDAP server
#dnpass =
dnpass = dovecot

# LDAP protocol version to use. Likely 2 or 3.
ldap_version = 2
#ldap_version = 3

# LDAP base
#base = uid=someone, dc=foo, dc=bar, dc=org
base = o=hosting,dc=akforecast

# Dereference: never, searching, finding, always
deref = never

# Search scope: base, onelevel, subtree
scope = subtree

# User attributes in order:
#  Virtual user name (user at domain)
#  Home directory
#  MAIL environment
#  System user name (for getting user's groups from /etc/group)
#    - For virtual users you don't want to use this, so this defaults to
none.
#  System UID
#  System GID
#user_attrs = uid,homeDirectory,,,uidNumber,gidNumber
user_attrs = mail,homeDirectory,,,,

# Filter for user lookup. Some variables can be used:
#   %u - username
#   %n - user part in user at domain, same as %u if there's no domain
#   %d - domain part in user at domain, empty if user there's no domain
#user_filter = (&(objectClass=posixAccount)(uid=%u))
user_filter =
(&(objectClass=JammMailAccount)(mail=%u)(accountActive=TRUE)(delete=FALSE))

# Password checking attributes in order:
#  Virtual user name (user at domain)
#  Password, may optionally start with {type}, eg. {crypt}
#pass_attrs = uid,userPassword
pass_attrs = mail,userPassword

# Filter for password lookups
#pass_filter = (&(objectClass=posixAccount)(uid=%u))
pass_filter =
(&(objectClass=JammMailAccount)(mail=%u)(accountActive=TRUE)(delete=FALSE))

# Default password scheme. "{scheme}" before password overrides this.
# Currently supported schemes include PLAIN, PLAIN-MD5, DIGEST-MD5,
CRYPT
#default_pass_scheme = CRYPT
default_pass_scheme = PLAIN

# You can use same UID and GID for all user accounts if you really want
to.
# If the UID/GID is still found from LDAP reply, it overrides these
values.
user_global_uid = 1051
user_global_gid = 1051

----------------------------------------------------

/etc/dovecot/dovecot.conf:

[root at salcha openldap]# cat /etc/dovecot/dovecot.conf
## Dovecot 1.0 configuration file

# Default values are shown after each value, it's not required to
uncomment
# any of the lines. Exception to this are paths, they're just examples
# with real defaults being based on configure options. The paths listed
here
# are for configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var
# --with-ssldir=/etc/ssl

# Base directory where to store runtime data.
#base_dir = /var/run/dovecot/

# Protocols we want to be serving:
#  imap imaps pop3 pop3s
protocols = imap imaps
#protocols = imap

# IP or host address where to listen in for connections. It's not
currently
# possible to specify multiple addresses. "*" listens in all IPv4
interfaces.
# "[::]" listens in all IPv6 interfaces, but may also listen in all IPv4
# interfaces depending on the operating system. You can specify ports
with
# "host:port".
#imap_listen = *
#pop3_listen = *
#imap_listen = 127.0.0.1
imap_listen = *

# IP or host address where to listen in for SSL connections. Defaults
# to above non-SSL equilevants if not specified.
imaps_listen = *
#pop3s_listen =

# Disable SSL/TLS support.
ssl_disable = no
#ssl_disable = yes

# PEM encoded X.509 SSL/TLS certificate and private key. They're opened
before
# dropping root privileges, so keep the key file unreadable by anyone
but
# root. Included doc/mkcert.sh can be used to easily generate
self-signed
# certificate, just make sure to update the domains in
dovecot-openssl.cnf
#ssl_cert_file = /etc/ssl/certs/dovecot.pem
#ssl_key_file = /etc/ssl/private/dovecot.pem
ssl_cert_file = /usr/share/ssl/hosting.example/climate_cert.pem
ssl_key_file = /usr/share/ssl/hosting.example/climate_private_key.pem

# SSL parameter file. Master process generates this file for login
processes.
# It contains Diffie Hellman and RSA parameters.
#ssl_parameters_file = /var/run/dovecot/ssl-parameters.dat

# How often to regenerate the SSL parameters file. Generation is quite
CPU
# intensive operation. The value is in hours, 0 disables regeneration
# entirely.
#ssl_parameters_regenerate = 24

# Disable LOGIN command and all other plaintext authentications unless
# SSL/TLS is used (LOGINDISABLED capability). Note that 127.*.*.* and
# IPv6 ::1 addresses are considered secure, this setting has no effect
if
# you connect from those addresses.
#disable_plaintext_auth = yes
disable_plaintext_auth = no

# Use this logfile instead of syslog(). /dev/stderr can be used if you
want to
# use stderr for logging (ONLY /dev/stderr - otherwise it is closed).
#log_path =

# For informational messages, use this logfile instead of the default
#info_log_path =

# Prefix for each line written to log file. % codes are in strftime(3)
# format.
#log_timestamp = "%b %d %H:%M:%S "

##
## Login processes
##

# Directory where authentication process places authentication UNIX
sockets
# which login needs to be able to connect to. The sockets are created
when
# running as root, so you don't have to worry about permissions. Note
that
# everything in this directory is deleted when Dovecot is started.
#login_dir = /var/run/dovecot/login

# chroot login process to the login_dir. Only reason not to do this is
if you
# wish to run the whole Dovecot without roots.
#login_chroot = yes


##
## IMAP login process
##

login = imap

# Executable location.
#login_executable = /usr/libexec/dovecot/imap-login

# User to use for the login process. Create a completely new user for
this,
# and don't use it anywhere else. The user must also belong to a group
where
# only it has access, it's used to control access for authentication
process.
login_user = dovecot

# Set max. process size in megabytes. If you don't use
# login_process_per_connection you might need to grow this.
#login_process_size = 32

# Should each login be processed in it's own process (yes), or should
one
# login process be allowed to process multiple connections (no)? Yes is
more
# secure, espcially with SSL/TLS enabled. No is faster since there's no
need
# to create processes all the time.
#login_process_per_connection = yes

# Number of login processes to create. If login_process_per_user is
# yes, this is the number of extra processes waiting for users to log
in.
#login_processes_count = 3

# Maximum number of extra login processes to create. The extra process
count
# usually stays at login_processes_count, but when multiple users start
logging
# in at the same time more extra processes are created. To prevent
fork-bombing
# we check only once in a second if new processes should be created - if
all
# of them are used at the time, we double their amount until limit set
by this
# setting is reached. This setting is used only if login_process_per_use
is yes.
#login_max_processes_count = 128

# Maximum number of connections allowed in login state. When this limit
is
# reached, the oldest connections are dropped. If login_process_per_user
# is no, this is a per-process value, so the absolute maximum number of
users
# logging in actually login_processes_count * max_logging_users.
#login_max_logging_users = 256

##
## POP3 login process
##

# Settings default to same as above, so you don't have to set anything
# unless you want to override them.

login = pop3

# Exception to above rule being the executable location.
#login_executable = /usr/libexec/dovecot/pop3-login

##
## Mail processes
##

# Maximum number of running mail processes. When this limit is reached,
# new users aren't allowed to log in.
#max_mail_processes = 1024

# Show more verbose process titles (in ps). Currently shows user name
and
# IP address. Useful for seeing who are actually using the IMAP
processes
# (eg. shared mailboxes or if same uid is used for multiple accounts).
#verbose_proctitle = no

# Show protocol level SSL errors.
#verbose_ssl = no

# Valid UID range for users, defaults to 500 and above. This is mostly
# to make sure that users can't log in as daemons or other system users.
# Note that denying root logins is hardcoded to dovecot binary and can't
# be done even if first_valid_uid is set to 0.
#first_valid_uid = 500
#last_valid_uid = 0
first_valid_uid = 1051
last_valid_uid = 1051

# Valid GID range for users, defaults to non-root/wheel. Users having
# non-valid GID as primary group ID aren't allowed to log in. If user
# belongs to supplementary groups with non-valid GIDs, those groups are
# not set.
#first_valid_gid = 1
#last_valid_gid = 0
first_valid_gid = 1051
last_valid_gid = 1051

# Grant access to these extra groups for mail processes. Typical use
would be
# to give "mail" group write access to /var/mail to be able to create
dotlocks.
#mail_extra_groups =

# ':' separated list of directories under which chrooting is allowed for
mail
# processes (ie. /var/mail will allow chrooting to /var/mail/foo/bar
too).
# This setting doesn't affect login_chroot or auth_chroot variables.
# WARNING: Never add directories here which local users can modify, that
# may lead to root exploit. Usually this should be done only if you
don't
# allow shell access for users. See doc/configuration.txt for more
information.
#valid_chroot_dirs =
valid_chroot_dirs = /vhosts/vmail

# Default chroot directory for mail processes. This can be overridden by
# giving /./ in user's home directory (eg. /home/./user chroots into
/home).
#mail_chroot =

# Default MAIL environment to use when it's not set. By leaving this
empty
# dovecot tries to do some automatic detection as described in
# doc/mail-storages.txt. There's a few special variables you can use:
#
#   %u - username
#   %n - user part in user at domain, same as %u if there's no domain
#   %d - domain part in user at domain, empty if user there's no domain
#   %h - home directory
#
# You can also limit a width of string by giving the number of max.
characters
# after the '%' character. For example %1u gives the first character of
# username. Some examples:
#
#   default_mail_env = maildir:/var/mail/%1u/%u/Maildir
#   default_mail_env = mbox:~/mail/:INBOX=/var/mail/%u
#   default_mail_env = mbox:/var/mail/%d/%n/:INDEX=/var/indexes/%d/%n
#
#default_mail_env =
default_mail_env = maildir:/vhosts/vmail/%d/%n

# Space-separated list of fields to cache for all mails. Currently these
# fields are allowed followed by a list of commands they speed up:
#
#  Envelope      - FETCH ENVELOPE and SEARCH FROM, TO, CC, BCC, SUBJECT,
#                  SENTBEFORE, SENTON, SENTSINCE, HEADER MESSAGE-ID,
#                  HEADER IN-REPLY-TO
#  Body          - FETCH BODY
#  Bodystructure - FETCH BODY, BODYSTRUCTURE
#  MessagePart   - FETCH BODY[1.2.3] (ie. body parts), RFC822.SIZE,
#                  SEARCH SMALLER, LARGER, also speeds up
BODY/BODYSTRUCTURE
#                  generation. This is always set with mbox mailboxes,
and
#                  also default with Maildir.
#
# Different IMAP clients work in different ways, that's why Dovecot by
default
# only caches MessagePart which speeds up most operations. Whenever
client
# does something where caching could be used, the field is automatically
marked
# to be cached later. For example after FETCH BODY the BODY will be
cached
# for all new messages. Normally you should leave this alone, unless you
know
# what most of your IMAP clients are. Caching more fields than needed
makes
# the index files larger and generate useless I/O.
#
# With maildir there's one extra optimization - if nothing is cached,
indexing
# the maildir becomes much faster since it's not opening any of the mail
files.
# This could be useful if your IMAP clients access only new mails.

#mail_cache_fields = MessagePart

# Space-separated list of fields that Dovecot should never set to be
cached.
# Useful if you want to save disk space at the cost of more I/O when the
fields
# needed.
#mail_never_cache_fields =

# Workarounds for various client bugs:
#   oe6-fetch-no-newmail:
#     Never send EXISTS/RECENT when replying to FETCH command. Outlook
Express
#     seems to think they are FETCH replies and gives user "Message no
longer
#     in server" error. Note that OE6 still breaks even with this
workaround
#     if synchronization is set to "Headers Only".
#   outlook-idle:
#     Outlook and Outlook Express never abort IDLE command, so if no
mail
#     arrives in half a hour, Dovecot closes the connection. This is
still
#     fine, except Outlook doesn't connect back so you don't see if new
mail
#     arrives.
#   outlook-pop3-no-nuls:
#     Outlook and Outlook Express hang if mails contain NUL characters.
#     This setting replaces them with 0x80 character.
#client_workarounds =

# Dovecot can notify client of new mail in selected mailbox soon after
it's
# received. This setting specifies the minimum interval in seconds
between
# new mail notifications to client - internally they may be checked more
or
# less often. Setting this to 0 disables the checking.
# NOTE: Evolution client breaks with this option when it's trying to
APPEND.
#mailbox_check_interval = 0

# Like mailbox_check_interval, but used for IDLE command.
#mailbox_idle_check_interval = 30

# Allow full filesystem access to clients. There's no access checks
other than
# what the operating system does for the active UID/GID. It works with
both
# maildir and mboxes, allowing you to prefix mailboxes names with eg.
/path/
# or ~user/.
#mail_full_filesystem_access = no

# Maximum allowed length for custom flag name. It's only forced when
trying
# to create new flags.
#mail_max_flag_length = 50

# Save mails with CR+LF instead of plain LF. This makes sending those
mails
# take less CPU, especially with sendfile() syscall with Linux and
FreeBSD.
# But it also creates a bit more disk I/O which may just make it slower.
#mail_save_crlf = no

# Use mmap() instead of read() to read mail files. read() seems to be a
bit
# faster with my Linux/x86 and it's better with NFS, so that's the
default.
#mail_read_mmaped = no

# By default LIST command returns all entries in maildir beginning with
dot.
# Enabling this option makes Dovecot return only entries which are
directories.
# This is done by stat()ing each entry, so it causes more disk I/O.
# (For systems setting struct dirent->d_type, this check is free and
it's
# done always regardless of this setting)
#maildir_stat_dirs = no

# Copy mail to another folders using hard links. This is much faster
than
# actually copying the file. This is problematic only if something
modifies
# the mail in one folder but doesn't want it modified in the others. I
don't
# know any MUA which would modify mail files directly. IMAP protocol
also
# requires that the mails don't change, so it would be problematic in
any case.
# If you care about performance, enable it.
#maildir_copy_with_hardlinks = no

# Check if mails' content has been changed by external programs. This
slows
# down things as extra stat() needs to be called for each file. If
changes are
# noticed, the message is treated as a new message, since IMAP protocol
# specifies that existing messages are immutable.
#maildir_check_content_changes = no

# Which locking methods to use for locking mbox. There's three
available:
#  dotlock: Create <mailbox>.lock file. This is the oldest and most
NFS-safe
#           solution. If you want to use /var/mail/ like directory, the
users
#           will need write access to that directory.
#  fcntl  : Use this if possible. Works with NFS too if lockd is used.
#  flock  : May not exist in all systems. Doesn't work with NFS.
#
# You can use both fcntl and flock too; if you do the order they're
declared
# with is important to avoid deadlocks if other MTAs/MUAs are using both
fcntl
# and flock. Some operating systems don't allow using both of them
# simultaneously, eg. BSDs. If dotlock is used, it's always created
first.
#mbox_locks = dotlock fcntl

# Should we create dotlock file even when we want only a read-lock?
Setting
# this to yes hurts the performance when the mailbox is accessed
simultaneously
# by multiple processes, but it's needed for reliable reading if no
other
# locking methods are available.
#mbox_read_dotlock = no

# Maximum time in seconds to wait for lock (all of them) before
aborting.
#mbox_lock_timeout = 300

# If dotlock exists but the mailbox isn't modified in any way, override
the
# lock file after this many seconds.
#mbox_dotlock_change_timeout = 30

# umask to use for mail files and directories
#umask = 0077

# Drop all privileges before exec()ing the mail process. This is mostly
# meant for debugging, otherwise you don't get core dumps. Note that
setting
# this to yes means that log file is opened as the logged in user, which
# might not work. It could also be a small security risk if you use
single UID
# for multiple users, as the users could ptrace() each others processes
then.
#mail_drop_priv_before_exec = no

##
## IMAP process
##

# Executable location
#imap_executable = /usr/libexec/dovecot/imap

# Set max. process size in megabytes. Most of the memory goes to
mmap()ing
# files, so it shouldn't harm much even if this limit is set pretty
high.
#imap_process_size = 256

# Support for dynamically loadable modules.
#imap_use_modules = no
#imap_modules = /usr/lib/dovecot/imap

##
## POP3 process
##

# Executable location
#pop3_executable = /usr/libexec/dovecot/pop3

# Set max. process size in megabytes. Most of the memory goes to
mmap()ing
# files, so it shouldn't harm much even if this limit is set pretty
high.
#pop3_process_size = 256

# Support for dynamically loadable modules.
#pop3_use_modules = no
#pop3_modules = /usr/lib/dovecot/pop3

##
## Authentication processes
##

# An Authentication process is a child process used by Dovecot that
# handles the authentication steps. The steps cover an authentication
# mechanism (auth_mechanisms, how the client authenticates in the IMAP
or
# POP3 protocol), which password database should be queried
(auth_passdb),
# and which user database should be queried (auth_userdb, to obtain
# UID, GID, and location of the user's mailbox/home directory).
#
# You can have multiple processes, though a typical configuration will
# have only one. Each time "auth = xx" is seen, a new process
# definition is started. The point of multiple processes is to be able
# to set stricter permissions. (See auth_user below.)
#
# Just remember that only one Authentication process is asked for the
# password, so you can't have different passwords accessible through
# different process definitions (unless they have different
# auth_mechanisms, and you're ok with having different password for
# each mechanisms).

# Authentication process name.
auth = default

# Specifies how the client authenticates in the IMAP protocol.
# Space separated list of permitted authentication mechanisms:
#   anonymous plain digest-md5 cram-md5
#
# anonymous - No authentication required.
# plain - The password is sent as plain text. All IMAP/POP3 clients
#  support this, and the password can be encrypted by Dovecot to match
#  any of the encryption schemes used in password databases.
# digest-md5 and cram-md5 - both encrypt the password so it is more
#  secure in transit, but are not well supported by clients, and
#  require that the password database use a matching encryption
#  scheme (or be in plaintext).
#
# See auth.txt for more details.
#
# If you are using SSL there is less benefit to digest-md5 and
# cram-md5 as the communication is already encrypted.
auth_mechanisms = plain

# Space separated list of realms for SASL authentication mechanisms that
need
# them. You can leave it empty if you don't want to support multiple
realms.
# Many clients simply use the first one listed here, so keep the default
realm
# first.
#auth_realms =

# Default realm/domain to use if none was specified. This is used for
both
# SASL realms and appending @domain to username in plaintext logins.
#auth_default_realm =

# Where user database is kept:
#   passwd: /etc/passwd or similiar, using getpwnam()
#   passwd-file <path>: passwd-like file with specified location
#   static uid=<uid> gid=<gid> home=<dir template>: static settings
#   vpopmail: vpopmail library
#   ldap <config path>: LDAP, see doc/dovecot-ldap.conf
#   pgsql <config path>: a PostgreSQL database, see
doc/dovecot-pgsql.conf
#auth_userdb = passwd
auth_userdb = ldap /etc/dovecot/dovecot-ldap.conf

# Where password database is kept:
#   passwd: /etc/passwd or similiar, using getpwnam()
#   shadow: /etc/shadow or similiar, using getspnam()
#   pam [<service> | *]: PAM authentication
#   passwd-file <path>: passwd-like file with specified location
#   vpopmail: vpopmail authentication
#   ldap <config path>: LDAP, see doc/dovecot-ldap.conf
#   pgsql <config path>: a PostgreSQL database, see
doc/dovecot-pgsql.conf
#auth_passdb = pgsql /usr/local/etc/dovecot-pgsql.conf
#auth_passdb = passwd
auth_passdb = ldap /etc/dovecot/dovecot-ldap.conf

#auth_executable = /usr/libexec/dovecot/dovecot-auth

# Set max. process size in megabytes.
#auth_process_size = 256

# User to use for the process. This user needs access to only user and
# password databases, nothing else. Only shadow and pam authentication
# requires roots, so use something else if possible. Note that passwd
# authentication with BSDs internally accesses shadow files, which also
# requires roots.
#auth_user = root
auth_user = dovecot

# Directory where to chroot the process. Most authentication backends
don't
# work if this is set, and there's no point chrooting if auth_user is
root.
#auth_chroot =

# Number of authentication processes to create
#auth_count = 1

# List of allowed characters in username. If the user-given username
contains
# a character not listed in here, the login automatically fails. This is
just
# an extra check to make sure user can't exploit any potential quote
escaping
# vulnerabilities with SQL/LDAP databases. If you want to allow all
characters,
# set this value to empty.
#auth_username_chars =
abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@

# Username to use for users logging in with ANONYMOUS SASL mechanism
#auth_anonymous_username = anonymous

# More verbose logging. Useful for figuring out why authentication isn't
# working.
#auth_verbose = no

# Even more verbose logging for debugging purposes. Shows for example
SQL
# queries.
#auth_debug = no

# digest-md5 authentication process. It requires special MD5 passwords
which
# /etc/shadow and PAM doesn't support, so we never need roots to handle
it.
# Note that the passwd-file is opened before chrooting and dropping root
# privileges, so it may be 0600-root owned file.

#auth = digest_md5
#auth_mechanisms = digest-md5
#auth_realms =
#auth_userdb = passwd-file /etc/passwd.imap
#auth_passdb = passwd-file /etc/passwd.imap
#auth_user = imapauth
#auth_chroot =

# if you plan to use only passwd-file, you don't need the two auth
processes,
# simply set "auth_methods = plain digest-md5"