[Samba] Rights issue on GPO

Achim Gottinger achim at ag-web.biz
Sat Jun 25 14:11:46 UTC 2016



Am 25.06.2016 um 10:24 schrieb Rowland penny:
> On 24/06/16 22:08, Achim Gottinger wrote:
>>
>>
>> Am 24.06.2016 um 22:35 schrieb Achim Gottinger:
>>>
>>>
>>> Am 24.06.2016 um 21:24 schrieb Rowland penny:
>>>> On 24/06/16 19:47, lingpanda101 at gmail.com wrote:
>>>>> On 6/24/2016 11:40 AM, mathias dufresne wrote:
>>>>>>
>>>>>>
>>>>>> 2016-06-24 15:24 GMT+02:00 lingpanda101 at gmail.com 
>>>>>> <mailto:lingpanda101 at gmail.com> <lingpanda101 at gmail.com 
>>>>>> <mailto:lingpanda101 at gmail.com>>:
>>>>>>
>>>>>>     On 6/22/2016 12:21 PM, mathias dufresne wrote:
>>>>>>
>>>>>>         2016-06-22 16:37 GMT+02:00 L.P.H. van Belle <belle at bazuin.nl
>>>>>>         <mailto:belle at bazuin.nl>>:
>>>>>>
>>>>>>             @Mathias,
>>>>>>
>>>>>>             Pretty strange then, running some years like this 
>>>>>> without
>>>>>>             any problem.
>>>>>>             Yes we had few problems with "rights" in sysvol, but i
>>>>>>             fixed this all
>>>>>>             outside linux, and with that i mean. Changed rights from
>>>>>>             within windows or
>>>>>>             added registry changes or patches, or a local clean 
>>>>>> up of
>>>>>>             the policies.
>>>>>>
>>>>>>             At the install of my DC2 i also synced the idmap.ldb, 
>>>>>> and
>>>>>>             then a
>>>>>>             net idmap flush on both servers to make my both dc's 
>>>>>> in sync.
>>>>>>             And i keep it in sync with my rsync/unison setup.
>>>>>>
>>>>>>             All new added, but i'll keep an eye also in this and 
>>>>>> i'll
>>>>>>             recheck my logs.
>>>>>>             But i dont think i'll find anything here.
>>>>>>             I'll keep notice on your "workaround".
>>>>>>
>>>>>>             Which backend are you using matias?
>>>>>>             Mine : (idmap config NTDOMAIN : backend = ad)
>>>>>>
>>>>>>
>>>>>>             Gr.
>>>>>>
>>>>>>             Louis
>>>>>>
>>>>>>
>>>>>>         OK you keep idmap.ldb synched, that's what I missed until 
>>>>>> few
>>>>>>         days and was
>>>>>>         the reason that is was not working.
>>>>>>         Our choice to give each and users and groups into AD some 
>>>>>> xID
>>>>>>         is only to
>>>>>>         avoid usage of mapping. I expect the synchronization of
>>>>>>         idmap.ldb (if done
>>>>>>         often enough) would be sufficient. But I don't always like
>>>>>>         magic : )
>>>>>>
>>>>>>         Thank you for precisions !
>>>>>>
>>>>>>
>>>>>>         Cheers all
>>>>>>
>>>>>>
>>>>>>                 -----Oorspronkelijk bericht-----
>>>>>>                 Van: samba [mailto:samba-bounces at lists.samba.org
>>>>>> <mailto:samba-bounces at lists.samba.org>] Namens mathias
>>>>>>
>>>>>>             dufresne
>>>>>>
>>>>>>                 Verzonden: woensdag 22 juni 2016 15:31
>>>>>>                 Aan: lingpanda101 at gmail.com
>>>>>>                 <mailto:lingpanda101 at gmail.com>
>>>>>>                 CC: samba
>>>>>>                 Onderwerp: Re: [Samba] Rights issue on GPO
>>>>>>
>>>>>>                 @LPH van Belle
>>>>>>                 I did tried (and still use) "acl_xattr:ignore system
>>>>>>                 acls = yes" as shown
>>>>>>                 on the first mail of that thread. And even using 
>>>>>> that
>>>>>>                 rights errors on
>>>>>>
>>>>>>             GPO
>>>>>>
>>>>>>                 files _are_ an issue. Otherwise that thread won't 
>>>>>> have
>>>>>>                 been opened of
>>>>>>                 course : )
>>>>>>
>>>>>>                 Regarding how we decided to workaround almost
>>>>>>                 definitively with that was
>>>>>>                 to
>>>>>>                 give every users and groups in AD some xID, also 
>>>>>> those
>>>>>>                 in CN=Builtin and
>>>>>>                 CN=Users. We also cleaned our idmap.ldb to keep 
>>>>>> inside
>>>>>>                 only special users
>>>>>>                 /
>>>>>>                 groups (as "local system" / S-1-5-18, "guests" /
>>>>>>                 S-1-5-32-546...).
>>>>>>                 We also add some rsync to keep idmap.ldb 
>>>>>> synchronized
>>>>>>                 on all our DC, for
>>>>>>                 these special items have same mapped xID in case 
>>>>>> they
>>>>>>                 are used (and so
>>>>>>                 mapped).
>>>>>>
>>>>>>                 Doing that id mapper has no reason to define by 
>>>>>> itself
>>>>>>                 some xID to users
>>>>>>                 and groups contained into AD as they already have 
>>>>>> some
>>>>>>                 xID.
>>>>>>
>>>>>>                 Until now it seems to work fine...
>>>>>>
>>>>>>
>>>>>>                 2016-06-22 15:09 GMT+02:00 lingpanda101 at gmail.com
>>>>>>                 <mailto:lingpanda101 at gmail.com>
>>>>>>                 <lingpanda101 at gmail.com 
>>>>>> <mailto:lingpanda101 at gmail.com>>:
>>>>>>
>>>>>>                     On 6/22/2016 8:53 AM, mj wrote:
>>>>>>
>>>>>>
>>>>>>                         On 06/22/2016 02:44 PM, 
>>>>>> lingpanda101 at gmail.com
>>>>>> <mailto:lingpanda101 at gmail.com> wrote:
>>>>>>
>>>>>>                             Why is is when I do a getfacl I do 
>>>>>> not see
>>>>>>                             the mapping of BUILTIN
>>>>>>
>>>>>>             like
>>>>>>
>>>>>>                             others?
>>>>>>
>>>>>>                         do you have winbind in /etc/nsswitch.conf?
>>>>>>
>>>>>>                         mj
>>>>>>
>>>>>>
>>>>>>                     I also thought winbind was only necessary on
>>>>>>                     member servers.
>>>>>>
>>>>>>                     --
>>>>>>                     -James
>>>>>>
>>>>>>
>>>>>>
>>>>>>                     --
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>>>>>>
>>>>>>
>>>>>>     If I assign every user a UID and select groups a GID by 
>>>>>> utilizing
>>>>>>     rfc2307 on my DC's. Would I still benefit from keeping idmap.ldb
>>>>>>     synchronized? I'm thinking XID's are obsolete at that point?
>>>>>>
>>>>>>
>>>>>> Only users and groups in AD will avoid id mapper by that 
>>>>>> workaround. But there are others accounts ("local system", 
>>>>>> "guest", "local administrator"...) all these accounts exist on MS 
>>>>>> Windows clients, and so they can all do stuff on Sysvol and so 
>>>>>> they can all go through id mapper.
>>>>>>
>>>>>> So no. There no way (for me at least :) to totally avoid id 
>>>>>> mapper and so you should keep idmap.ldb synched.
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>     --     -James
>>>>>>
>>>>>>
>>>>>>     --     To unsubscribe from this list go to the following URL 
>>>>>> and read the
>>>>>>     instructions: https://lists.samba.org/mailman/options/samba
>>>>>>
>>>>>>
>>>>>
>>>>> I'm in the process now of creating a script to sync idmap.ldb. 
>>>>> Does anyone have one at the moment? Is it best practice to stop 
>>>>> samba before replacing idmap.ldb on the additional DC's? My script 
>>>>> will currently watch for any idmap.ldb changes and create a hot 
>>>>> backup if a change is detected. It will then send to the other 
>>>>> DC's via rsync. I'm thinking starting and stopping samba isn't 
>>>>> ideal during production hours.
>>>>>
>>>>
>>>> If you are running Samba >= 4.2.0 with the separate 'winbindd' 
>>>> binary, there is no reason to sync idmap.ldb. Syncing idmap was/is 
>>>> only required if you use 'winbind' that is built into the 'samba' 
>>>> binary.
>>>>
>>>> Rowland
>>>>
>>>>
>>> Hello Rowland,
>>>
>>> If you take an look on your sysvol rights there are two still 
>>> unresoved groups SECURITY\Local System and SECURITY\Autheticated 
>>> Users. These show up with gid's from idmap.ldb in the acl list and 
>>> therefore can not be mapped during rsync. So at least these two 
>>> groups need idntical mapping on all dc's. It is however not 
>>> neccessary to keep idmap in sync as long as no ther security groups 
>>> are used.
>>>
>>> achim~
>>>
>> To be more specific the groups belongig to "WellKnown Security 
>> Principals" are not mapped. I called them security groups above.
>> See here for an list:
>> https://technet.microsoft.com/en-us/library/dn617202(v=ws.11).aspx#BKMK_AuthenticatedUser 
>>
>>
>
> I know all of the above, and you seem to be using fixes that had to be 
> used with a Samba 4 AD DC that used the 'winbind' part of the 'samba' 
> binary.
>
> When Samba 4.2.0 came out, 'winbind' was replaced with the separate 
> 'winbindd' binary (the same one used on a domain member). This means 
> that, even though an AD object may be mapped to a number, the DC knows 
> what AD object that is.
>
> This means you do not need to sync idmap.ldb between DCs if you use 
> Samba >= 4.2.0 with the separate 'winbindd' binary.
>
> Rowland
Look at my other posts today, there are still interferences between the 
posix acls and the xattr acl's whom can cause sysvol to be not 
accessible or accessible or even writeable by unwanted groups. Did my 
tests on debian jessie using sernet 4.2 packages.





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