[Freeipa-devel] Time-based account policies

[Jan Cholasta]

Dne 24.3.2015 v 18:08 Stanislav Láznička napsal(a):
> On 03/24/2015 08:53 AM, Jan Cholasta wrote:
>> Dne 24.3.2015 v 08:40 Martin Kosek napsal(a):
>>> On 03/24/2015 08:20 AM, Jakub Hrozek wrote:
>>>> On Tue, Mar 24, 2015 at 08:07:53AM +0100, Martin Kosek wrote:
>>>>> On 03/24/2015 07:16 AM, Jan Cholasta wrote:
>>>>>> Dne 23.3.2015 v 20:17 Standa Láznička napsal(a):
>>>>> ...
>>>>>>>> Given the above, HBAC rules could contain (time, anchor), where
>>>>>>>> anchor
>>>>>>>> is "UTC", "user local time" or "host local time".
>>>>>>> Truth is, it was not really clear to me from the last week's
>>>>>>> discussion
>>>>>>> whose "Local Time" to use - do we use host's or do we use
>>>>>>> user's?  It
>>>>>>> would make sense to me to use the user's local time. But then you
>>>>>>> would
>>>>>>> need to really store at least the timezone information with each
>>>>>>> user
>>>>>>> object. And that information should probably change with user moving
>>>>>>> between different timezones. That's quite a pickle I am in right
>>>>>>> here.
>>>>>>
>>>>>> IMO whether to use user or host local time depends on organization
>>>>>> local
>>>>>> policy, hence my suggestion to support both.
>>>>>
>>>>> I am bit confused, I would like to make sure we are on the same
>>>>> page with
>>>>> regards to Local Time. When the Local Time rule is created, anchor
>>>>> will be set
>>>>> to "Local Time". Then SSSD would simply use host's local time, in
>>>>> whichever
>>>>> time zone the HBAC host is.
>>>>
>>>> Yes, that was my understanding also.
>>>>
>>>>>
>>>>> So this is the default host enforcement. For the user, you want to
>>>>> let SSSD
>>>>> check authenticated user's entry, to see if there is a timezone
>>>>> information?
>>>>> This would of course depend on the information being available. For
>>>>> AD users,
>>>>> you would need to set it in ID Views or similar.
>>>>
>>>> Yes, also in a previous e-mail, there was a suggestion to change
>>>> timezones by admin when the user changes timezones -- I didn't like
>>>> that
>>>> part, it seems really error prone and tedious. *If* there was this
>>>> choice, it should not be the default, rather the default should also be
>>>> host local time IMO.
>>
>> I don't think you can expect host-local time to be good enough for
>> everyone.
>>
>>>
>>> Host local time zone was the original case I expected. Enforcing
>>> *user* local
>>> time zone is where this discussion started. Honze proposed making
>>> this an
>>> option - leaving us to 3 different time modes:
>>>
>>> * UTC - stored as (time + olson time zone), enforcement is clear
>>> * Host Local Time - stored as  (time + Host Local Time), enforcement by
>>> /etc/localtime
>>> * User Local Time - stored as  (time + User Local Time), enforcement
>>> by ???
>>>
>>> So the rule may be:
>>> * Employee Foo can access web service Bar only in his work hours
>>
>> Correct.
>>
>>>
>>> IMO, it is realistic for an administrator to set the time zone
>>> setting in the
>>> employee entry. Of course, it gets tricky when the user starts moving
>>> around
>>> the globe...
>>>
>>
>> It doesn't have to be the administrator, it can be automated by a 3rd
>> party service:
>>
>>  1. Employee schedules bussiness trip in time management system
>>  2. Manager approves the bussiness trip in the time management system
>>  3. The time management system takes care of changing the employee's
>> user object timezone when the bussiness trip starts and ends.
>>
> I have to say I am not very sure about this anymore. Although it would
> be a great feature to have users' local time policies, it brings a lot
> of traps on the way. The responsibility of keeping the LDAP database
> consistent with reality is laid to a 3rd party application. If that
> breaks or does not work well, this responsibility might be sometimes
> transferred to admin. But if there's a lot of people traveling at a
> time... I'm having mixed feelings about this.

Timezones or not, there is always the responsibility of keeping LDAP in 
sync with reality. I'm just saying there are possibilities besides doing 
it manually.

Anyway, I think both user-local and host-local time can also be 
implemented based on group membership, without storing anything with 
user and host object, with HBAC rules like this:

   Rule name: allow_tz_europe_prague_users
   Member groups: tz_europe_prague
   Host category: all
   Service category: all
   Access time: (timeofday=0800-1600 dayofweek=Mon-Fri)
   Time zone: Europe/Prague
   Description: Allow users in Europe/Prague access during bussiness hours
   Enabled: TRUE

   Rule name: allow_tz_europe_prague_hosts
   User category: all
   Member hostgroups: tz_europe_prague
   Service category: all
   Access time: (timeofday=0800-1600 dayofweek=Mon-Fri)
   Time zone: Europe/Prague
   Description: Allow access to hosts in Europe/Prague during bussiness 
hours
   Enabled: TRUE

I guess things might get complicated if you want to do limit access 
based on both user and host local time, but I'm not sure if anyone would 
actually want to do that.

-- 
Jan Cholasta