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User Management : The Default Implementation

General Notes

The default user management implementation stores user/group information in the content repository. In contrast to Jackrabbit 2.x, which by default used a single, dedicated workspace for user/group data, this data will as of Oak 1.0 be stored separately for each JCR workspace.

Consequently, the UserManager associated with the editing sessions, performs all actions with this editing session. This corresponds to the behavior as defined the alternative implementation present with Jackrabbit 2.x ((see Jackrabbit 2.x UserPerWorkspaceUserManager).

  • The Oak implementation is build on the Oak API. This allows for double usage as extension to the JCR API as well as within the Oak layer (aka SPI).
  • The UserManager is always associated with the same JCR workspace as the editing Session from which the class has been obtained.
  • Changes made to the user management API are always transient and require Session#save() to be persisted.
  • In case of any failure during user management related write operations the API consumer is in charge of specifically revert pending or invalid transient modifications or calling Session#refresh(false).

Differences wrt Jackrabbit 2.x

A summary of all changes with respect to the former implementation present with Jackrabbit 2.x is present in the corresponding section.

Built-in Users and Special Groups

The setup of builtin user and group accounts is triggered by the configured WorkspaceInitializer associated with the user management configuration (see Configuration section below).

The default user management implementation in OAK comes with an initializer that creates the following builtin user accounts:

Administrator

The admin user is always being created. The ID of this user is retrieved from the user configuration parameter PARAM_ADMIN_ID, which defaults to admin.

As of OAK 1.0 however the administrator user might be created without initial password forcing the application to set the password upon start (see PARAM_OMIT_ADMIN_PW configuration parameter).

Anonymous User

In contrast to Jackrabbit 2.x the anonymous (or guest) user is optional. Creation will be skipped if the value of the PARAM_ANONYMOUS_ID configuration parameter is null or empty.

Note, that the anonymous user will always be created without specifying a password in order to prevent regular login with SimpleCredentials. The proper way to obtain a guest session is:

Repository#login(new GuestCredentials(), wspName);

See section Authentication for further information about guest login.

Everyone Group

The default user management implementation in Oak contains special handling for the optional group that represents the everyone principal, which is marked by the reserved principal name and by definition has all other principals as members.

This special group always contains all users/groups as member and cannot be edited with user management API. As of OAK this fact is consistently reflected in all group membership related methods. See also Principal Management.

User Management Operations

Reading Authorizables

Handling of the Authorizable ID
  • As of Oak 1.0 the node type definition of rep:Authorizable defines a new property rep:authorizableId which is intended to store the ID of a user or group.
  • This property is protected and system maintained and cannot be changed after creation through user management API calls.
  • The default implementation comes with a dedicated property index for rep:authorizableId which asserts the uniqueness of that ID.
  • For backwards compatibility with Jackrabbit 2.x the ID specified during creation is also reflected in the jcr:uuid (protected and mandatory), which is used for the lookup.
  • Authorizable#getID returns the string value contained in rep:authorizableID and for backwards compatibility falls back on the node name in case the rep:authorizableId property is missing.
  • The name of the authorizable node is generated based on a configurable implementation of the AuthorizableNodeName interface (see configuration section below). By default it uses the ID as name hint and includes a conversion to a valid JCR node name.
equals() and hashCode()

The implementation of Object#equals() and Object#hashCode() for user and groups slightly differs from Jackrabbit 2.x. It no longer relies on the sameness of the underlaying JCR node but only compares IDs and the user manager instance.

Creating Authorizables

  • The rep:password property is no longer defined to be mandatory. Therefore a new user might be created without specifying a password. Note however, that User#changePassword does not allow to remove the password property.
  • Since version 1.1.0 Oak supports the new API to create dedicated system users JCR-3802.

Searching

XPathQueryBuilder

Oak 1.0 comes with a default XPATH based implementation of the QueryBuilder interface which is passed to the query upon calling UserManager#findAuthorizables(Query).

Group Membership

See section Group Membership for details.

Autosave Behavior

Due to the nature of the UserManager (see above) we decided to drop the auto-save behavior in the default implementation present with OAK. Consequently,

  • UserManager#autoSave(boolean) throws UnsupportedRepositoryOperationException
  • UserManager#isAutoSave() always returns false

See also PARAM_SUPPORT_AUTOSAVE below; while this should not be needed if application code has been written against the Jackrabbit API (and thus testing if auto-save mode is enabled or not) this configuration option can be used as last resort.

XML Import

As of Oak 1.0 user and group nodes can be imported both with Session and Workspace import. Other differences compared to Jackrabbit 2.x:

  • Importing an authorizable to another tree than the configured user/group node will only failed upon save (-> see UserValidator during the Root#commit). With Jackrabbit 2.x core it used to fail immediately.
  • The BestEffort behavior is now also implemented for the import of impersonators (was missing in Jackrabbit /2.x).

Password Expiry and Force Initial Password Change

Since Oak 1.1.0 the default user management and authentication implementation provides password expiry and initial password change.

By default, these features are disabled. See section Password Expiry and Force Initial Password Change for details.

Password History

Since Oak 1.3.3 the default user management implementation provides password history support. By default, this feature is disabled.

See section Password History for details.

Impersonation

The default implementation of the Impersonation interface comes with the following limitations and features:

  • only user principals can be granted impersonation
  • every user can impersonate itself
  • the admin user always can impersonate all users (and therefore cannot be granted impersonation)
  • the Configuration allows to define a list of user or group principals that can impersonate all users (since Oak 1.54.0, see OAK-10173)

Representation in the Repository

The following block lists the built-in node types related to user management tasks:

[rep:Authorizable] > mix:referenceable, nt:hierarchyNode
  abstract
  + * (nt:base) = nt:unstructured VERSION
  - rep:principalName  (STRING) protected mandatory
  - rep:authorizableId (STRING) protected /* @since oak 1.0 */
  - * (UNDEFINED)
  - * (UNDEFINED) multiple

[rep:User] > rep:Authorizable, rep:Impersonatable
  + rep:pwd (rep:Password) = rep:Password protected /* @since oak 1.1.0 */
  - rep:password (STRING) protected
  - rep:disabled (STRING) protected

[rep:SystemUser] > rep:User /* @since oak 1.1.0 */

[rep:Impersonatable]
  mixin
  - rep:impersonators (STRING) protected multiple
    
/* @since oak 1.1.0 */
[rep:Password]
  - * (UNDEFINED) protected
  - * (UNDEFINED) protected multiple

[rep:Group] > rep:Authorizable, rep:MemberReferences
  + rep:members (rep:Members) = rep:Members multiple protected VERSION /* @deprecated since oak 1.0 */
  + rep:membersList (rep:MemberReferencesList) = rep:MemberReferencesList protected COPY /* @since oak 1.0 */


[rep:AuthorizableFolder] > nt:hierarchyNode
  + * (rep:Authorizable) = rep:User VERSION
  + * (rep:AuthorizableFolder) = rep:AuthorizableFolder VERSION    

/* @since oak 1.0 */
[rep:MemberReferences]
  - rep:members (WEAKREFERENCE) protected multiple < 'rep:Authorizable'

/* @since oak 1.0 */
[rep:MemberReferencesList]
  + * (rep:MemberReferences) = rep:MemberReferences protected COPY
  
/* @deprecated since oak 1.0 */
[rep:Members]
  orderable
  + * (rep:Members) = rep:Members protected multiple
  - * (WEAKREFERENCE) protected < 'rep:Authorizable'

Validation

The consistency of this content structure is asserted by a dedicated UserValidator. The corresponding errors are all of type Constraint with the following codes:

Code Message
0020 Admin user cannot be disabled
0021 Invalid jcr:uuid for authorizable (creation)
0022 Changing Id, principal name after creation
0023 Invalid jcr:uuid for authorizable (mod)
0024 Password may not be plain text
0025 Attempt to remove id, principalname or pw
0026 Mandatory property rep:principalName missing
0027 The admin user cannot be removed
0028 Attempt to create outside of configured scope
0029 Intermediate folders not rep:AuthorizableFolder
0030 Missing uuid for group (check for cyclic membership)
0031 Cyclic group membership (see OAK-6072)
0032 Attempt to set password with system user
0033 Attempt to add rep:pwd node to a system user

Configuration

The following user management specific methods are present with the UserConfiguration as of OAK 1.0:

  • getUserManager: Obtain a new user manager instance

Configuration Parameters supported by the default implementation

Parameter Type Default Description
PARAM_ADMIN_ID String “admin”
PARAM_OMIT_ADMIN_PW boolean false
PARAM_ANONYMOUS_ID String “anonymous” (nullable)
PARAM_USER_PATH String “/rep:security/rep:authorizables/rep:users”
PARAM_GROUP_PATH String “/rep:security/rep:authorizables/rep:groups”
PARAM_DEFAULT_DEPTH int 2
PARAM_PASSWORD_HASH_ALGORITHM String “SHA-256”
PARAM_PASSWORD_HASH_ITERATIONS int 1000
PARAM_PASSWORD_SALT_SIZE int 8
PARAM_AUTHORIZABLE_NODE_NAME AuthorizableNodeName AuthorizableNodeName#DEFAULT
PARAM_AUTHORIZABLE_ACTION_PROVIDER AuthorizableActionProvider DefaultAuthorizableActionProvider
PARAM_SUPPORT_AUTOSAVE boolean false
PARAM_IMPORT_BEHAVIOR String (“abort”, “ignore”, “besteffort”) “ignore”
PARAM_PASSWORD_MAX_AGE int 0
PARAM_PASSWORD_INITIAL_CHANGE boolean false
PARAM_PASSWORD_HISTORY_SIZE int (upper limit: 1000) 0
PARAM_CACHE_EXPIRATION long 0 Number of milliseconds until the internal principal cache expires. If not set or equal/lower than zero no cache is created/evaluated.
PARAM_CACHE_MAX_STALE long 0 Optional configuration defining the number of milliseconds for which a stale principal cache can be served if another thread is already writing the cache. If not set or zero no stale cache is returned and group principals are read from the persistence without being cached. This configuration option only takes effect if the principal cache is enabled with a ‘Principal Cache Expiration’ value greater than zero.
PARAM_ENABLE_RFC7613_USERCASE_MAPPED_PROFILE boolean false
PARAM_IMPERSONATOR_PRINCIPAL_NAMES String {} List of users who can impersonate and groups whose members can impersonate any user (since Oak 1.54.0, OAK-10173).

The following configuration parameters present with the default implementation in Jackrabbit 2.x are no longer supported and will be ignored:

  • compatibleJR16
  • autoExpandTree
  • autoExpandSize
  • groupMembershipSplitSize

The optional cacheExpiration configuration option listed above is discussed in detail in section Caching Results of Principal Resolution. It is not related to user management s.str. but affects the implementation specific PrincipalProvider implementation exposed by UserConfiguration.getUserPrincipalProvider.

Pluggability

Within the default user management implementation the following parts can be modified or extended at runtime by providing corresponding OSGi services or passing appropriate configuration parameters exposing the custom implementations:

  • AuthorizableActionProvider: Defines the authorizable actions, see Authorizable Actions.
  • AuthorizableNodeName: Defines the generation of the authorizable node names in case the user management implementation stores user information in the repository. See Authorizable Node Name Generation.
  • UserAuthenticationFactory: see below

UserAuthenticationFactory : Authenticating Users

Since Oak 1.1.5 the default user management implementation allows to configure and thus replace the default UserAuthenticationFactory, which links the user management implementation with the authentication (specifically the uid/pw-login) as it exposes the Authentication implementation to be used for verification of the specified credentials according to details provided by a given user management implementation.

Examples
Example UserAuthenticationFactory
@Component()
@Service(UserAuthenticationFactory.class)
public class MyUserAuthenticationFactory implements UserAuthenticationFactory {

    private Set<String> ids = Collections.emptySet();

    public MyUserAuthenticationFactory() {}

    //--------------------------------------< UserAuthenticationFactory >---
    @Override
    Authentication getAuthentication(@Nonnull UserConfiguration configuration, @Nonnull Root root, @Nullable String userId) {
        final boolean canAuthenticate = (userId != null && ids.contains(userId));
        return new Authentication() {
            @Override
            public boolean authenticate(@Nullable Credentials credentials) {
                return canAuthenticate;
            }
        };
    }

    //------------------------------------------------< SCR Integration >---
    @Activate
    private void activate(Map<String, Object> properties) {
         ids = ImmutableSet.copyOf(PropertiesUtil.toStringArray(properties.get("ids"), new String[0]));
    }
}