VPopMail
========

Dovecot supports authenticating against external VPopMail
[http://www.inter7.com/index.php?page=vpopmail] virtual domain manager. Dovecot
must have been configured with '--with-vpopmail' to enable this. You can check
this with 'dovecot --build-options'. See also <VMailMgr> [HowTo.VMailMgr.txt]
for another similar virtual domain manager.

If the vpopmail database contains plaintext passwords, it can be used for
non-plaintext authentication as well.

passdb parameters:

 * cache_key: If set, you can use 'auth_cache' with VPopMail. See <PAM>
   [PasswordDatabase.PAM.txt] for more information about it.
 * webmail=IP: If IP address is specified, connections from it are assumed to
   come from webmail and VPopMail's webmail usage restrictions apply.

userdb parameters:

 * cache_key: Like in passdb.
 * quota_template=TEMPLATE: Template to specify quota rule, %q in value expands
   to Maildir++ quota.

Example
-------

---%<-------------------------------------------------------------------------
passdb {
  driver = vpopmail
  args = webmail=127.0.0.1
}
userdb {
  driver = vpopmail
  args = quota_template=quota_rule=*:backend=%q
}
---%<-------------------------------------------------------------------------

VPopMail + MySQL
================

Alternatively, you can use the SQL backend with the following configuration:

---%<-------------------------------------------------------------------------
driver = mysql
connect = host=/var/run/mysqld/mysqld.sock user=vpopmail
password=YOURPASSWORDHERE dbname=vpopmail

default_pass_scheme = PLAIN
password_query = SELECT CONCAT(pw_name, '@', pw_domain) AS user, \
  pw_clear_passwd AS password \
  FROM vpopmail \
  WHERE pw_name = '%n' AND pw_domain = '%d'
user_query = SELECT pw_dir as home, \
  89 AS uid, 89 AS gid \
  FROM vpopmail \
  WHERE pw_name = '%n' AND pw_domain = '%d'
---%<-------------------------------------------------------------------------

VPopMail + MySQL + pw_gid (disable_imap, disable_webmail) and vlimits support
=============================================================================

The above example doesn't support vpopmail's abilities to disable access to
services like IMAP, webmail etc. which is controlled by vmoduser and
vmoddomlimits.

VPopMail uses pw_gid column in the database to store this information. It has a
binary format and every bit of the number stored in this column is responsible
for a different access limit.

As defined in the vpopmail.h:

---%<-------------------------------------------------------------------------
/* gid flags */
#define NO_PASSWD_CHNG 0x01
#define NO_POP         0x02
#define NO_WEBMAIL     0x04
#define NO_IMAP        0x08
#define BOUNCE_MAIL    0x10
#define NO_RELAY       0x20
#define NO_DIALUP      0x40
#define V_USER0       0x080
#define V_USER1       0x100
#define V_USER2       0x200
#define V_USER3       0x400
#define NO_SMTP       0x800
#define QA_ADMIN     0x1000
#define V_OVERRIDE   0x2000
---%<-------------------------------------------------------------------------

+ if vpopmail has been compiled with domain limits (--enable-mysql-limits)
domain wise limits will be defined in a table called "limits" where there are
fields like disable_imap and disable_webmail which values by default are NULL
and 1 if option is set. The use of NULLs in limits table is a bit problematic
because in order to properly handle this situation we're going to have replace
NULL with a numeric value. Of course we're going to join vpopmail table (the
table holding users) with limits table using LEFT JOIN.

Here's the config taken directly from my install:

---%<-------------------------------------------------------------------------
#
user_query = SELECT pw_name,89 as uid, 89 as gid, pw_dir as home FROM vpopmail
WHERE pw_name = '%n' AND pw_domain = '%d'
#The below passes all users and doesn't care for vpopmail limits (pw_gid column
or vlimits table)
#password_query = SELECT pw_passwd as password FROM vpopmail WHERE pw_name =
'%n' AND pw_domain = '%d'
#
#A little bit more complicated query to support vpopmail pw_gid flags and
vlimits for domain
#explanation:
#We're using bitwise operations on pw_gid.
#as defined in vpopmail.h:
#- 0x04 - disable webmail flag
#- 0x08 - disable imap flag
#
# !(pw_gid & 8) means - if 8th bit of pw_gid is not set
# !(pw_gid & 4) means - if 4th bit of pw_gid is not set
# (pw_gid & 8192) means - if 14th bit of pw_gid is set (ignore vlimits)
#
# additionally because we're using LEFT JOIN we have to take care of NULLs for
rows that don't return any records from the right table hence the use of
COALESCE() function
# !(pw_gid & 4) (disable webmail flag) is used in conjuntion with
'%r'!="127.0.0.1" which means that it will only apply to connections
originating from hosts other than localhost
#
# So the below query supports pw_gid and vlimits settings for user account and
domains but no domain limit overrides
#
#password_query = select pw_passwd as password FROM vpopmail LEFT JOIN limits
ON vpopmail.pw_domain=limits.domain WHERE pw_name='%n' and pw_domain='%d' and (
!(pw_gid & 8) and ('%r'!='127.0.0.1' or !(pw_gid & 4)) and ( '%r'!='127.0.0.1'
or COALESCE(disable_webmail,0)!=1) and COALESCE(disable_imap,0)!=1);
#
# The below adds support for vlimits override on user account (vmoduser -o)
#
#logically this means: show password for user=%n at domain=%d when imap on the
account is not disabled and connection is not comming from localhost when
webmail access on the account is not disabled and if imap for the domain is not
disabled and (connection is not comming from localhost when webmail access for
the domain is not disabled) when vlimits are not overriden on the account
#
password_query = select pw_passwd as password FROM vpopmail LEFT JOIN limits ON
vpopmail.pw_domain=limits.domain WHERE pw_name='%n' and pw_domain='%d' and
!(pw_gid & 8) and ('%r'!='127.0.0.1' or !(pw_gid & 4)) and ( ('%r'!='127.0.0.1'
or COALESCE(disable_webmail,0)!=1) and COALESCE(disable_imap,0)!=1 or (pw_gid &
8192) );
---%<-------------------------------------------------------------------------

Please be aware that disable_webmail is strictly binded to the IP address hard
coded in the query. In this example webmail connections come from the same
machine that the IMAP server is running on using 127.0.0.1 IP address. So the
webmail client is configured with something like eg. $IMAP_SERVER="127.0.0.1". 
If your webmail client is on a different machine you need to change 127.0.0.1
to your webmail's server IP.

Also - be aware that dovecot caches SQL results (configurable) so if you're
testing the above config on an account that has logged on succesfully within
the cache timeout period and you changed the settings on it using eg. vmoduser
-i test@example.com account which effectively disabled IMAP access for this
account dovecot can still log this user on because the result of the password
query has been stored in cache and used.

(This file was created from the wiki on 2019-06-19 12:42)