OMERO 5.4 introduced the concept of a restricted administrator. These are generally more powerful than normal OMERO users and group owners but they do not have all the powers of full administrators such as root
. A restricted administrator is the same as a full administrator except that in specific ways it is as if they are not an administrator at all. Those specific ways are exactly the restrictions listed in their user's Experimenter.config
property. For that property, a name of AdminPrivilege:Dance
(just an example!) with a value of false
indicates that the restricted administrator's ability to dance is not that of a full administrator. Their ability to dance is instead that of a normal user who is not a member of the system
group. A member of the system
group with an empty config
property is a full administrator without restrictions.
The :model_source:meta.ome.xml mapping <src/main/resources/mappings/meta.ome.xml> lists all the values of the :slicedoc_blitz:AdminPrivilege <omero/model/AdminPrivilege.html> enumeration. Each of those values corresponds to a kind of operation for which full administrators have greater privilege. If an administrator has any of the below restrictions then they do not have greater privilege for the corresponding operation. It instead becomes as if they were but a normal user in that respect.
Chgrp
move data to other groups
Chown
give data to other users
WriteOwned
create or edit OMERO model objects that have an owner and are not
OriginalFile
instancesWriteFile
create or edit
OriginalFile
objects that are in neither the managed repository nor the script repositoryWriteManagedRepo
create or edit
OriginalFile
objects that are in the managed repository, which is to where imported image files are uploadedWriteScriptRepo
create or edit
OriginalFile
objects that are in the script repository, which is where official scripts resideDeleteOwned
delete OMERO model objects that have an owner and are not
OriginalFile
instancesDeleteFile
delete
OriginalFile
objects that are in neither the managed repository nor the script repositoryDeleteManagedRepo
delete
OriginalFile
objects that are in the managed repository, which is to where imported image files are uploadedDeleteScriptRepo
delete
OriginalFile
objects that are in the script repository, which is where official scripts resideModifyGroup
make changes to groups, such as their name or permissions level
ModifyGroupMembership
make changes to who is a member or owner of which group
ModifyUser
make changes to users, such as their name or institution
Sudo
become another user
ReadSession
read other users' session UUIDs
It often makes sense to apply all but a certain bundle of restrictions to a user. For example, users working with other users' data may benefit from being able to go beyond their normal group restrictions only for the operations of WriteOwned
, WriteManagedRepo
, WriteScriptRepo
, Chgrp
. A facility manager importing on behalf of other users may appropriately be given all but the Sudo
restriction. A human resources representative may be given all but the ModifyGroup
, ModifyGroupMembership
, ModifyUser
restrictions. Much depends on how personnel roles are handled in each specific institution.
Warning
The ReadSession
restriction should be applied to all restricted administrators. Without that restriction members of the system
group can read other users' session UUIDs and join those sessions as the user. In contrast, while an administrator without the Sudo
restriction can become other users, the security system prevents their using sudo to elevate their own administrative powers. An administrator cannot sudo to become root
to escape their restrictions. :javadoc_server:A security filter <ome/security/basic/LightAdminPrivilegesSecurityFilter.html> assists in enforcing ReadSession
.
Since OMERO 5.4 the :slicedoc_blitz:admin service <omero/api/IAdmin.html> offers operations for managing restrictions on administrators. createLightSystemUser
creates a new restricted administrator. getAdminPrivileges
and setAdminPrivileges
manage the restrictions on an existing administrator.
Using setAdminPrivileges
to set an empty list of privileges fills that user's Experimenter.config
property with a false
value for every AdminPrivilege
name. That user does not thus become like a normal user: they retain all administrative powers not explicitly restricted, such as being able to read all users' images.
Even for a normal user who is not a member of the system
group and has no administrative powers, restrictions can still be set in their Experimenter.config
property. Such restrictions have no effect while that user is not an administrator as they have no administrative powers to restrict.
getCurrentAdminPrivileges
is useful for OMERO clients to find how the currently logged-in administrator is restricted. getAdminsWithPrivileges
identifies the administrators who are sufficiently unrestricted in a given way.
OMERO model objects have a details property <model details
property>
that bears information on object permissions
<permissions object>
. In addition to the existing methods like canEdit
and canDelete
, the canChgrp
and canChown
methods were introduced in OMERO 5.4. Client software may find these permissions methods a useful guide as to what the current administrator may do to which objects.
Since OMERO 5.4 the :slicedoc_blitz:event context <omero/sys/EventContext.html> for the current session, available from the admin service, has additional data members:
adminPrivileges
that lists the restrictions not applying to the current session. For non-administrators this list is empty as if they are wholly restricted. For restricted administrators it lists only the privileges that they enjoy. For full administrators all privileges are listed.sudoerId
,sudoerName
that for sudo sessions notes which administrator it was who became the current user.
AdminServiceTest <components/tools/OmeroJava/test/integration/AdminServiceTest.java>
tests the admin service operations for working with restrictions.LightAdminPrivilegesTest <components/tools/OmeroJava/test/integration/LightAdminPrivilegesTest.java>
tests the restrictions from a security point of view: checking that applying even just one restriction to a user prevents all means of performing the corresponding operation.LightAdminRolesTest <components/tools/OmeroJava/test/integration/LightAdminRolesTest.java>
tests various user workflows: checking that with all but a given set of restrictions an administrator may perform useful sequences of operations.
Since OMERO 5.4 the repo
property of OriginalFile <OMERO model
class OriginalFile>
is mapped into the OMERO object model. Because the interpretation of an OriginalFile
instance depends upon with which repository the file is associated, for security reasons the server greatly restricts the mutation of this property: users cannot simply switch a file from one repository to another.
The server must allow some setting of repo
. It currently uses an indirect means of authenticating legitimately set values. Each running server has a secret key recorded in the uuid property of Node
<OMERO model class Node>
. This key is not available to OMERO clients, it is internal to the server. To set a new file's repo
the :javadoc_blitz:repository DAO <ome/services/blitz/repo/RepositoryDaoImpl.html> prefixes the file's name
with the server's secret key. A database trigger recognizes this key from the node
table, removes the prefix from the name
, then allows the value of repo
to be set.
While :javadoc_server:BasicACLVoter <ome/security/basic/BasicACLVoter.html> and :javadoc_server:OmeroInterceptor <ome/security/basic/OmeroInterceptor.html> carry the bulk of the burden of enforcing restrictions on administrators, together with :javadoc_server:AdminImpl <ome/logic/AdminImpl.html> for the user and group management restrictions, the database system itself is also a key enforcement mechanism.
The :slicedoc_blitz:update service <omero/api/IUpdate.html> is one means by which administrators may attempt to perform restricted operations. Hibernate's interceptors are not wholly suited to blocking exactly the prohibited actions so further barriers are built into the database that trigger upon specific data changes. The database must therefore have enough information to judge if an operation is permitted. OMERO 5.4 introduced two tables:
_roles
notes the server's configured IDs for special users and groups, such as
root
andsystem
which are both usually0
; set by :javadoc_server:DBUserCheck <ome/services/util/DBUserCheck.html> on server startup_current_admin_privileges
notes the restrictions not applying to the current user on a per-transaction basis; maintained by :javadoc_server:OmeroInterceptor <ome/security/basic/OmeroInterceptor.html> and frequently cleared by :javadoc_server:LightAdminPrivilegesCleanup <ome/security/basic/LightAdminPrivilegesCleanup.html>
An example database trigger would be user_config_delete_trigger
on the experimenter_config
table. This trigger raises an exception if, for example, an AdminPrivilege:Dance
name with a false
value is to be removed from the config
of a member of the system
group by a user who themself is restricted from dancing. This prevents the administrator whose dancing is restricted from lifting that restriction from another administrator so that they may be the one to newly dance.