Compartmentalized groups or locations sharing a domain

[dstoliker]

We are a franchise organization and all of our locations, including the corporate office, share a domain for email. We've implemented Zimbra for the corporate office and are now looking to offer Zimbra to our franchisees. The problem, however, is how to keep everything compartmentalized - resources in particular.

For example, an employee at a franchise location shouldn't be able to schedule a meeting in a conference room at the corporate headquarters. I thought Class of Service would be the answer to this one, but if I have a user in one COS, and a resource in another COS, the user can still see free/busy info on the resource and schedule its use. This brings up another question: What does COS on a resource actually do?

How have other administrators solved this issue?

[mmorse]

5.0.7: Bug 22913 - Access control for free busy and resources (ie permission to invite)

ZimbraServer/docs/accesscontrol.txt
OVERVIEW
========
Currently, we have "mail object" based access control mechanism in that 
ACLs are generally associated with a single object in a user's Mailbox,
for example, a folder or a tag.  The ACLs for mail object based access 
controls are persisted in the user's database, in the METADATA column on the 
MAIL_ITEM row for the folder or tag.   ZimbraServer/docs/acl.txt describes 
"mail object" based access controls.

In addition to the above access control scheme, it is required that we 
support access control on the account level, where permissions are 
granted on the account level, instead of on individual folders or tags.

Implementation of account based access controls is not changing any aspect 
of "mail object" based access controls.   However many of the terminologies 
and concepts are shared between the two.

This document describes the account based access control mechanism.  
On a side note, the role based delegated admin feature in GnR will be built 
on the same model.


RIGHTS
======
Unlike mail object based access controls, rights for account based controls 
are defined on a "higher", or "functionality" level.  For example, instead 
of the generic combination of "read', 'write" rights that can be applied to 
all mail objects, rights for account based access controls are like 
"viewFreeBusy", "invite", ...

Currently, the following rights are supported:
    - invite
    - viewFreeBusy

zmmailbox helpPermissions command describes each rights in more details.


NEGATIVE RIGHTS
===============
Negative right are to specifically deny certain privileges to the "grantee".
Negative rights will take precedence over positive rights.

For example, if you granted "no invite" to user A, then invites from user A 
would not be able to automatically book the target account's calendar for the 
appointment.  Regardless of what other grants for the same right is applied to 
user A(e.g. allow all authed users).


GRANTEES
========
Like mail object based access controls, to avoid support calls:
(1) a user always has full, irrevocable rights to their own mailbox.
and 
(2) administrators are allowed full access to everything on the system,
    until we have a full-featured role based delegated admin implementation.

Rights can be granted(allowed or denied) to other principals.  
The type of supported grantees are:

        user        - a Zimbra user
        group       - a Zimbra group(distribution list)
        all-authed  - all authed Zimbra usres
        public      - the public


CONFLICTING GRANTEES
====================
When more than one ACEs of an ACL on the same right match a grantee and all ACEs 
don't agree on the same allow/deny for the right, the ACE with the most specific 
match takes precedence; and if all matching ACEs are equally related to the grantee, 
the negative ACE takes precedence.

example 1:
    - ACL has:
          . allow user A for right R
          . deny group G for right R
    - user A is in group G
    => user A will be allowed for right R, because user match is more specific than group match.
     
     
example 2:
    - ACL has:
          . allow group G1 for right R
          . deny group G2 for right R
    - group G2 is a member of group G1
    - user A is a member of group G2
    => user A will be denied for right R, because G2 is a more specific match than G1.
     
     
example 3:
    - ACL has:
          . allow group G1 for right R
          . deny group G2 for right R
    - group G1 and G2 are not member of each other
    - user A is in both group G1 and group G2
    => user A will be denied, because negative ACE takes precedence.
    
                
If multiple ACEs conflict for a right for the same grantee, this is a wrong setting, which 
should not happen if all modification to ACLs are done via the supported granting/revoking 
interfaces: SOAP and zmmailbox.   If for any reason such ACL does exist (e.g. 
via ldapmodify, or zmprov ma command(should we make zimberaACE immutable so 
it cannot be modified by zmprov?)), the result is **unexpected**, depending on 
which ACE is encountered first when we iterate through the ACL.  We could've 
spent more cycles detecting such settings and honor the negative ACE if there 
is one, but currently the implementation choice is not to do so.

e.g. - ACL has:
           . allow user A for right R
           . deny user A for right R
     => user A could be allowed or denied for right R, randomly.  
  

ACL STORAGE AND SERIALIZATION FORMAT
====================================
ACLs are persisted in LDAP in the multi-valued "zimbraACE" attribute on the 
target LDAP entry.  ACE stands for "access control entry", multiple ACEs makes 
an ACL(access control list).

ACEs are serialized in LDAP in the following format:

    <grantee> <grantee-type> [-]<right>

        grantee: For user and group grantees, zimbraId of the account/distribution list
                 For all-authed and public grantees, pseudo UUID recognized by the code.
                 
        grantee-type: usr | grp | all | pub
        
        right: one of the supported right.
               if a '-' (minus sign) is prepended to the right, it means the right is 
               specifically denied.
                        
    e.g. fe0e1a88-e6e3-4fe1-b608-3ab6ce50351f grp -viewFreeBusy
         fd6227f2-87e6-4453-9ccc-16853a6f8d27 usr viewFreeBusy
         00000000-0000-0000-0000-000000000000 all viewFreeBusy
         99999999-9999-9999-9999-999999999999 pub invite
         
Note: zimbraACE should NOT be directly modified via zmprov or any LDAP tools.  
      They should only be modified via zmmailbox commands.  See GRANTING TOOLS below.
      
      
GRANTING TOOLS
==============
Before WEB UI is available for granting, revoking, viewing rights, zmmailbox is the sole 
tool that should be used for those tasks.

zmmailbox commands:

1. List all permission related commands
   command: help permission
   
   scope: any
   
   example:
       mbox> help permission

          getPermission(gp)            [opts] [right1 [right2...]]
            -v/--verbose                 verbose output
        
          grantPermission(grp)         {account {name}|group {name}|all|public {[-]permission}}
        
          listPermission(lp)           [opts] 
            -v/--verbose                 verbose output
        
          revokePermission(rvp)        {account {name}|group {name}|all|public {[-]permission}}
            
       
2. List and describe all permissions that can be granted 
   command: listPermission(lp) [opts] 
              -v/--verbose     verbose output
            
   scope: after a mailbox is selected
   
   example:
       mbox> sm user1@example.com
       mailbox: user1@example.com, size: 0 B, messages: 0, unread: 0
       
       mbox user1@example.com> lp -v
         invite: automatically add meeting invites from grantee to the target's calendar
             e.g. (1) When user Y is invited to a meeting, an appt is added to his calendar 
                      automatically(tentatively) only if invite is from A, B, C or anyone in group G. 
                  (2) Conf room Y can only be booked by users A, B, C and group G.

         viewFreeBusy: view free/busy
             e.g. Free/busy for Y can only be seen by users A, B, C and group G.
   
       
3. Get rights currently granted.
   command: getPermission(gp) [opts] [right1 [right2...]]
              -v/--verbose    verbose output
              
            Optional right(s) can be specified to get only ACEs for those rights.
            
   scope: after a mailbox is selected
   
   example:
       mbox> sm user1@example.com
       mailbox: user1@example.com, size: 0 B, messages: 0, unread: 0
       
       mbox user1@example.com> gp
             Permission      Type  Display
       ----------------  --------  -------
                 invite       all  
          -viewFreeBusy   account  user2@example.com
          -viewFreeBusy     group  groupX@example.com
           viewFreeBusy       all  
           viewFreeBusy    public  
           
       mbox user1@example.com> gp invite
             Permission      Type  Display
       ----------------  --------  -------
                 invite       all 

   Note: 
       - grants are sorted by Permission, then type(from the most specific to the least specific: 
         account, group, all, public), then grantee display name. 
       - To be consistent with the modifyFolderGrant(mfg) command, which is for mail object based permissions, 
         grantee types are displayed as account(for user grantee), group(for group grantee), all(for all-authed 
         grantee), and public(for public grantee).
         
         
4. Grant(allow or deny) a right to a grantee or a group of grantee. 
   To deny a right, put a '-' in front of the right.
   
   command: grantPermission(grp) {account {name}|group {name}|all|public {[-]right}}
   
   scope: after a mailbox is selected
   
   example:
       mbox> sm user1@example.com
       mailbox: user1@example.com, size: 0 B, messages: 0, unread: 0
       
       mbox user1@example.com> grp account user3 invite
         granted: 
           account user3@example.com invite
           
       mbox user1@example.com> grp group group1@foo.com -viewFreeBusy
         granted: 
           group group1@foo.com -viewFreeBusy
           
       mbox user1@example.com> grp group group2 invite
          granted: 
            group group2@example.com invite
            
       mbox user1@example.com> grp all viewFreeBusy
          granted: 
            all  viewFreeBusy
            
       mbox user1@example.com> grp public -viewFreeBusy
          granted: 
            public  -viewFreeBusy
 
       mbox user1@example.com> gp
             Permission      Type  Display
       ----------------  --------  -------
                 invite   account  user3@example.com
                 invite     group  group2@example.com
          -viewFreeBusy     group  group1@foo.com
          -viewFreeBusy    public  
           viewFreeBusy       all  
   
   Note: 
       (1) if domain is not given for account or group grantee, the domain of the selected 
           mailbox will be used. 
       (2) if a grantee currently has a grant(positive or negative) for a right, granting 
           to the same grantee with a different privilege overwrite the grant.  For example, 
           if user A currently is allowed the right to invite, "grp account A -invite" will 
           change the grant(i.e. ACE) from allowed to denied.
       (3) to complete remove a grant(i.e. an ACE) from a grantee, use the revokePermission(rvp) 
           command, see 5. below.    
                    
         
5. Revoke a right previously granted to a grantee or a group of grantees. 
   To revoke a denied right, put a '-' in front of the right.
   
   command: revokePermission(rvp) {account {name}|group {name}|all|public {[-]right}}
   
   scope: after a mailbox is selected
   
   example: 
       mbox> sm user1@example.com
       mailbox: user1@example.com, size: 0 B, messages: 0, unread: 0
       
       mbox user1@example.com> gp
             Permission      Type  Display
       ----------------  --------  -------
                 invite   account  user3@example.com
                 invite     group  group2@example.com
          -viewFreeBusy     group  group1@foo.com
          -viewFreeBusy    public  
           viewFreeBusy       all 

       mbox user1@example.com> rvp group group1@foo.com viewFreeBusy
         revoked 0 permission
         (didn't revoke any permission because group1@foo.com does not have a viewFreeBusy 
          grant, it only has a -viewFreeBusy grant)
          
       mbox user1@example.com> rvp group group1@foo.com -viewFreeBusy
         revoked: 
           group group1@foo.com -viewFreeBusy 
           
       mbox user1@example.com> rvp all viewFreeBusy
         revoked: 
           all  viewFreeBusy 
           
       mbox user1@example.com> rvp account  user3@example.com invite
         revoked: 
           account user3@example.com invite
           
       mbox user1@example.com> gp
             Permission      Type  Display
       ----------------  --------  -------
                 invite     group  group2@example.com
          -viewFreeBusy    public
               
               
   Note: when revoking a negative permission, "-" has to be prepended to the right, 
         otherwise the permission will not be revoked.  See example above.

[mmorse]

Pic of the simple way preferences > calendar tab:

So you could apply it on a dist list, you can also prevent that dist list from receiving mail so it's not a mailing list - just a group.

[dstoliker]

Hi Mike,

Thanks for your replies. So is that screen shot from the up and coming version 5.0.7 then?

[mmorse]

Yup - soon.

http://www.zimbra.com/forums/announc...html#post62754

[Russianspi]

Hi Mike. Sorry to piggyback on an old thread, but this seemed like the appropriate place. I've just noticed (and I don't know how I've missed it for the past year) that if you share something internally, you can share it with a user or a GROUP. Very cool...except I don't see a place for creating a group. Is this another name for a distribution list? Or am I just really missing something? And if it is a distribution list, and it changes, are changes in the list reflected in sharing permissions? Thanks!