[SOLVED] Re: LMTP Post login script for acl_groups

[lists at mlserv.org]

> Am 29.08.2019 um 11:23 schrieb Aki Tuomi via dovecot <dovecot at dovecot.org>:
> 
> 
> On 29.8.2019 12.18, R.N.S. via dovecot wrote:
>> 
>>> Am 28.08.2019 um 20:02 schrieb Aki Tuomi via dovecot <dovecot at dovecot.org>:
>>> 
>>> 
>>>> On 28/08/2019 21:01 R.N.S. via dovecot <dovecot at dovecot.org> wrote:
>>>> 
>>>> 
>>>>> Am 28.08.2019 um 19:46 schrieb Jakobus Schürz via dovecot <dovecot at dovecot.org>:
>>>>> 
>>>>> I think, i had the same problem as you.
>>>>> 
>>>>> When dovecot runs lmtp, no user is logged in, so there is no user from
>>>>> which you can get groups. So i think, my solution is (not really sure,
>>>>> if this is right, it's a long time ago, i played around) this transport
>>>>> in exim for local delivery
>>>>> 
>>>>> dovecot_delivery:             
>>>>> debug_print = "T: dovecot_delivery_pipe for $local_part@$domain
>>>>> translates to GET_LOCAL_MAIL"
>>>>> driver = pipe               
>>>>> command = /usr/lib/dovecot/deliver -d "GET_LOCAL_MAIL"
>>>>> message_prefix =
>>>>> message_suffix =
>>>>> delivery_date_add
>>>>> envelope_to_add             
>>>>> return_path_add             
>>>>> log_output
>>>>> user = MAILUSER
>>>>> group = MAILUSER
>>>>> 
>>>>> I have a really sophisticated setup with ldap... so GET_LOCAL_MAIL and
>>>>> MAILUSER are makros which get the email-adress and the mailuser for the
>>>>> receiving emailadress.
>>>>> 
>>>>> GET_LOCAL_MAIL could be $local_part@$domain
>>>>> MAILUSER is vmail in my setup, the user who owns all mailboxes
>>>>> 
>>>>> /usr/lib/dovecot/deliver is an alternative for the lmtp-delivery.
>>>> Unfortunately this way Postfix and Dovecot need to run on the same host.
>>>> 
>>>> I wonder, if this is a LMTP or Sieve issue. Maybe something can be done in sieve configuration to solve this?
>>>> 
>>>> Is there nobody from @Dovecot who could give some feedback :-) please :-)
>>>> 
>>>> Thanks
>>>> 
>>>> Christian
>>> It could be possible to solve this with auth lua script that would allow returning the acl groups as a string, instead of using post-login script.
>> I finally got it working with Lua.
>> 
>> Changes to the auth-ldap.conf.ext file:
>> --------------------------------------------------
>> userdb {
>>  driver = ldap
>>  args = /etc/dovecot/dovecot-ldap.conf.ext
>> 
>>  # Fetch acl_groups from LDAP with the Lua userdb script
>>  skip = never
>>  result_success = continue
>>  result_failure = return-fail
>> 
>>  # Default fields can be used to specify defaults that LDAP may override
>>  #default_fields = home=/home/virtual/%u
>> }
>> --------------------------------------------------
>> 
>> I created this auth-lua.conf.ext:
>> --------------------------------------------------
>> # https://wiki.dovecot.org/AuthDatabase/Lua
>> 
>> userdb {
>>   driver = lua
>>   args = file=/etc/dovecot/dovecot-auth-userdb.lua  blocking=yes
>> }
>> --------------------------------------------------
>> 
>> I added it in 10-auth.conf behind the LDAP auth include statement.
>> 
>> The Lua script looks like this:
>> --------------------------------------------------
>> require('io')
>> 
>> function auth_userdb_lookup(req)
>>  local bindpwfile = "/etc/dovecot/ldap-auth-userdb.secret"
>>  local base = "ou=people,ou=it,dc=roessner-net,dc=de"
>>  local binddn = "cn=dovecot," .. base
>> 
>>  local cmd = [=[
>>    /bin/sh -c "ldapsearch -LLL -ZZ -y $bindpwfile -xD $binddn -b $base '(rnsMSDovecotUser=$user)' rnsMSACLGroup | \
>>      grep rnsMSACLGroup | \
>>      awk -vORS=, '{ print \$2 }' | \
>>      sed 's/,$/\n/'"
>>  ]=]
>> 
>>  cmd = cmd:gsub('$(%w+)', { bindpwfile = bindpwfile })
>>  cmd = cmd:gsub('$(%w+)', { binddn = binddn })
>>  cmd = cmd:gsub('$(%w+)', { base = base })
>>  cmd = cmd:gsub('$(%w+)', { user = req.user })
>> 
>>  local handle = io.popen(cmd)
>>  local acl_groups = handle:read("*a")
>> 
>>  return dovecot.auth.USERDB_RESULT_OK, "acl_groups=" .. acl_groups
>> end
>> 
>> function script_init()
>>  return 0
>> end
>> 
>> function script_deinit()
>> end
>> 
>> -- vim: expandtab ts=2 sw=2
>> --------------------------------------------------
>> 
>> And this works for me :-)
>> 
>> Many thanks
>> 
>> Christian
> 
> There really is no LDAP module for your LUA?

I was too early with success :-(

Even the doveadm acl debug command shows that I would have all rights, mails are insert into the INBOX :-(

...
doveadm(lists at srvint.net): Info: User lists at srvint.net has rights: lookup read write write-seen write-deleted insert post expunge
doveadm(lists at srvint.net): Info: Mailbox found from dovecot-acl-list
doveadm(lists at srvint.net): Info: Mailbox is in public namespace
doveadm(lists at srvint.net): Info: Mailbox Public/Mailinglisten/Dovecot is visible in LIST

Why can't LMTP/Sieve insert the Mail to that place?

If I use a LDAP attribute with a comma separated list in the dovecot-ldap.conf.ext file, everything works. So what is different to the second Lua backend?

It is really a pain that acl_groups does not simply support multi values.

Maybe I will spend some more time for the Lua LDAP module, but for now, it is really frustrating.

Christian