[Freeipa-users] Access differentiation in group policy

[Исаев Виталий Анатольевич]

Here is our attempt to describe the problem in terms of IPA CLI commands:

kinit admin
ipa group-add --desc="Group 1" group1
ipa group-add --desc="Group 2" group2
ipa user-add --first="Admin" --last="Group 1" --password admin_group1
ipa user-add --first="Admin" --last="Group 2" --password admin_group2
ipa user-add --first="User" --last="Group 1" user_group1
ipa user-add --first="User" --last="Group 2" user_group2
ipa group-add-member --users=user_group1 group1
ipa group-add-member --users=admin_group1 group1
ipa group-add-member --users=user_group2 group2
ipa group-add-member --users=admin_group2 --password group2
ipa group-remove-member --users=user_group1,admin_group1,user_group2,admin_group2 ipausers
ipa permission-add perm_edit_sn_group1 --permission=write --attrs=sn --memberof=group1 --type=user
ipa permission-add perm_edit_member_group1 --permission=write --attrs=member --targetgroup=group1
ipa privilege-add priv_group1 --desc="Privilege Group1"
ipa privilege-add-permission priv_group1 --permissions=perm_edit_sn_group1,perm_edit_member_group1
ipa role-add role_group1 --desc="Role Group1"
ipa role-add-privilege role_group1 --privileges=priv_group1
ipa role-add-member role_group1 --users=admin_group1
kinit admin_group1
ipa user-mod user_group1 --last="Group 1"
// I can't change user_group2's lastname.
ipa user-mod user_group2 --last="Group 1"
// But I can add to group1 any users or user groups existing in IPA. How can I disallow the admin_group1 to add users or user groups from other isolated groups?
ipa group-add-member --users=user_group2 group1
// And now I can change user_group2's lastname.
ipa user-mod user_group2 --last="Group 1"

Thanks a lot. 

-----Original Message-----
From: Rob Crittenden [mailto:rcritten at redhat.com] 
Sent: Friday, November 08, 2013 8:48 PM
To: Исаев Виталий Анатольевич; freeipa-users at redhat.com
Subject: Re: [Freeipa-users] Access differentiation in group policy

Исаев Виталий Анатольевич wrote:
> Rob, I apologize, just one more question. We dealt with the editing of attributes, but it is still not clear if it is possible to restrict the user adding to isolated group in case of the user's membership in other isolated group.

I'm not sure I follow. As you can see, this sort of access control can get very complex :-) Can you provide an example of what you want to do?

rob

>
> -----Original Message-----
> From: Rob Crittenden [mailto:rcritten at redhat.com]
> Sent: Friday, November 08, 2013 7:47 PM
> To: Исаев Виталий Анатольевич; freeipa-users at redhat.com
> Subject: Re: [Freeipa-users] Access differentiation in group policy
>
> Исаев Виталий Анатольевич wrote:
>> Dear colleagues, we faced with an issue of access differentiation for 
>> junior IPA admins. Our idea was to create several (say, three – 
>> group1, group2, group3) isolated groups with one junior admin per group.
>>
>> The group isolation means that admin of group1 is not able to add to 
>> his group neither users nor subgroups – members of other global groups (i.e.
>> group2, group3)
>>
>> We have attempted to accomplish this by RBAC for every junior admin.
>> It was pointed out, that the admin can modify the objects (users,
>> subgroups) belonging to his group only.  However, every user enrolled 
>> to IPA can see all the other objects by default, therefore any junior 
>> admin can add users and subgroups FROM THE OTHER isolated group to 
>> his group with no restrictions.
>>
>> So the question is – how to implement (the specified) group “isolation”
>> in IPA?
>>
>> We’re running on the RHEL 6.4 with IPA 3.0. Thank you.
>
> You need to create some custom permissions that limit the capabilities by memberof.
>
> I set up a simple system with a couple of users:
>
> kinit admin
> ipa group-add --desc=g1 g1
> ipa group-add --desc=g2 g2
> ipa user-add --first=group1 --last=user1 g1u1 ipa user-add 
> --first=group2 --last=user1 g2u1 ipa group-add-member --users g1u1 g1 
> ipa group-add-member --users g2u1 g2 ipa user-add --first=group1 
> --last=admin1 g1a1 ipa group-add-member --users g1a1 g1 ipa passwd 
> g1a1
>
> g1a1 is going to be my junior admin
>
> Next I created a permission so junior admins can manage the telephone number. This permission allows the phone number attribute to be written only for members of the group g1.
>
> ipa permission-add --attrs=telephonenumber --memberof=g1 --permissions=write g1_modify_members ipa privilege-add g1_junior_admin --desc='Group 1 junior admin'
> ipa privilege-add-permission --permissions=g1_modify_members 
> g1_junior_admin ipa role-add --desc='Group 1 junior admin' group1 ipa 
> role-add-privilege --privileges=g1_junior_admin group1 ipa 
> role-add-member --users=g1a1 group1
>
> So members of the group1 role can modify the telephonenumber attribute of its members.
>
> Let's see it in action:
>
> kinit g1a1
> ipa user-mod --phone=410-555-1212 g1u1
> --------------------
> Modified user "g1u1"
> --------------------
>     User login: g1u1
>     First name: group1
>     Last name: user1
>     Home directory: /home/g1u1
>     Login shell: /bin/sh
>     Email address: g1u1 at example.com
>     UID: 1197000004
>     GID: 1197000004
>     Telephone Number: 410-555-1212
>     Account disabled: False
>     Password: False
>     Member of groups: ipausers, g1
>     Kerberos keys available: False
>
> Try another attribute and it fails as expected:
> ipa user-mod --fax=410-555-1212 g1u1
> ipa: ERROR: Insufficient access: Insufficient 'write' privilege to the 'facsimileTelephoneNumber' attribute of entry 'uid=g1u1,cn=users,cn=accounts,dc=example,dc=com'.
>
> Change the phone number of a non-member of the group and it also fails as expected:
> ipa user-mod --phone=410-555-1213 g2u1
> ipa: ERROR: Insufficient access: Insufficient 'write' privilege to the 'telephoneNumber' attribute of entry 'uid=g2u1,cn=users,cn=accounts,dc=example,dc=com'.
>
> rob
>