Package examples

Class PermissionAuthenticator

java.lang.Object

examples.PermissionAuthenticator

All Implemented Interfaces:

Authenticator

public class PermissionAuthenticator
extends Object
implements Authenticator

An authenticator implementation that shows one possible use of the Permission object and it's interactions with the Authentication API.

This authenticator uses the permission objects to maintain a list of denied users and denied objects. When the liberator requests an object, if the object is not listed and the user is not listed, then the authenticator will respon with an OK. A real implementation would be a lot more complex than this, but this shows the basics of how an object can be denied or allowed as the case may be. If an object or user changes from deny to allow, there needs to be no special processing as each request for that object will recheck the permissions. However when updates are not rechecked for every update for performance reasons, so when an object or users permission changes from allow to deny, we ahve to tell the liberator that the permissions have changed. We do this by invalidating a users session. In the case of a user permission changing we simply invalidate that users session, but in the case of an object, for performance reasons, we only try to invalidate the users that are actively interested in that object.

Constructor Summary

Constructors

Constructor	Description
PermissionAuthenticator()

Method Summary

Modifier and Type	Method	Description
AuthenticationResult	authoriseHTTP(AuthenticationUser user)	This method will be called when an HTTP directory access authorisation is required.
AuthenticationResult	checkPermissionUpdate(UserSession session, RTTPObject object, String key, Map<String,String> fieldValues)	Called on every update to a permission object to allow the Authenticator to authenticate each update based on content.
AuthenticationResult	checkRead(UserSession session, RTTPObject object, String requestedName)	This method will be called to check authentication every time a user tries to read an object.
AuthenticationResult	checkUpdate(UserSession session, RTTPObject object, String data)	Called on every update to an object (currently only news headline objects) to allow the Authenticator to authenticate each update based on content.
AuthenticationResult	checkUser(UserSession session)	The user login authorisation method which is called every time a user tries to login to the server.
AuthenticationResult	checkWrite(UserSession session, RTTPObject object, String requestedName, String contributionId, Map<String,String> fields)	This method will be called to check authentication every time a user attempts to create or write to an object.
AuthenticationResult	discardObject(UserSession session, RTTPObject object)	This method will be called when a user's session is no longer subscribed to an object.
void	globalPermissionUpdate(RTTPObject object, String key, Map<String,String> fieldValues, PermissionUpdateType type)	Called on every update to a global permission object to allow the Authenticator to receive structured control messages.
void	initialise(SessionManager sessionManager, DelayedResultReceiver delayedResultReceiver, ServerNode serverNode, String loggerName)	Called on startup of the Liberator Auth Module.
AuthenticationResult	mapObject(UserSession session, MapObject mapObject)	This method will be called every time a user tries to read an object (before checkRead).
AuthenticationResult	newObject(RTTPObject object, RTTPObject parent)	This method is called when a new object is created in the Liberator.
int	PermissionCheckUser(AuthenticationUser user)
AuthenticationResult	releaseObject(RTTPObject object)	This method will be called when the Liberator deletes an object.
AuthenticationResult	releaseUser(UserSession session)	This method will be called when the Liberator deletes the user session due to logout or timeout.
AuthenticationResult	requestObject(UserSession session, RTTPObject object)	This method will be called when a user's session becomes subscribed to an object.
void	shutdown()	Called when the Liberator is shutting down.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

PermissionAuthenticator

public PermissionAuthenticator()

Method Details

PermissionCheckUser

public int PermissionCheckUser(AuthenticationUser user)

initialise

public void initialise(SessionManager sessionManager,
 DelayedResultReceiver delayedResultReceiver,
 ServerNode serverNode,
 String loggerName)

Description copied from interface: Authenticator

Called on startup of the Liberator Auth Module.

Allows initialisation of required resources and connections. e.g. reading configuration files, connecting to a database or other external application, or constructing internal data structures.

The logger name can be used for obtaining the native logger java.util.logging.Logger.getLogger(String). This logger will log messages to the Liberator's auth log file.

Specified by:

initialise in interface Authenticator

Parameters:

sessionManager - a SessionManager instance that can be used for invalidating and ejecting user sessions in the Liberator.

delayedResultReceiver - a DelayedResultReceiver instance that can be used for sending delayed authentication results after an AuthenticationResult.DELAYED is used.

serverNode - a ServerNode instance that provides access to information about the server and its session count.

loggerName - the name of the logger that provides native logging output to the Liberator's auth log file (by default auth-rttpd.log).

checkUser

public AuthenticationResult checkUser(UserSession session)

Description copied from interface: Authenticator

The user login authorisation method which is called every time a user tries to login to the server.

This method should be used to perform authorisation of the user's credentials.

If the authentication requires the use of an external service (e.g. database) to verify the user credentials, the AuthenticationResult.DELAYED return code should be used, followed by a call to DelayedResultReceiver#delayedCheckUserResult when the result is available. This mechanism avoids the Liberator thread beeing blocked whilst waiting for the result, and the obvious associated performance impact.

N.B. The delayed result functionality is only available for the checkUser and mapObject methods. To avoid unnecessary delays during methods such as checkRead, if the user's permission set is contained in a remote database or service, then it can be beneficial to cache this locally at logon time during this method execution.
Subsequent permission checks such as checkRead can then access the locally cached permission set for optimal performance.
If the cached permissions are then modified, then SessionManager#invalidateAllSessions or SessionManager#invalidateSessions methods can be used as necessary to force the Liberator to re-validate the user's permissions.

Specified by:

checkUser in interface Authenticator

Parameters:

session - the UserSession object containing information about the user and their login details.

Returns:

an AuthenticationResult instance - usually AuthenticationResult.OK , AuthenticationResult.DENY or one of the specific failure results such as AuthenticationResult.INVALID_USER.

See Also:

• DelayedResultReceiver.delayedCheckUserResult(UserSession, AuthenticationResult)
• AuthenticationResult.DELAYED

releaseUser

public AuthenticationResult releaseUser(UserSession session)

Description copied from interface: Authenticator

This method will be called when the Liberator deletes the user session due to logout or timeout.

Use this call to clean-up any resources that may have been allocated to a session.

Specified by:

releaseUser in interface Authenticator

Parameters:

session - the UserSession object for the released session.

Returns:

an AuthenticationResult instance - this is currently ignored, so use only AuthenticationResult.OK.

newObject

public AuthenticationResult newObject(RTTPObject object,
 RTTPObject parent)

Description copied from interface: Authenticator

This method is called when a new object is created in the Liberator.

This is a notification method that can be used, for example, to pre-cache authentication information for the object. It will be called at the point of object creation in the Liberator, regardless of whether this object is created by a broadcast datasource, as the result of a user request or by an RTTP object creation by a user

Specified by:

newObject in interface Authenticator

Parameters:

object - the new RTTPObject that has been created.

parent - the parent object of the newly created object, or null if the new object is at the root level in the Liberator.

Returns:

an AuthenticationResult instance - this is currently ignored, so use only AuthenticationResult.OK.

releaseObject

public AuthenticationResult releaseObject(RTTPObject object)

Description copied from interface: Authenticator

This method will be called when the Liberator deletes an object.

Use this call to clean-up any resources that may have been allocated to the object.

Specified by:

releaseObject in interface Authenticator

Parameters:

object - the RTTPObject that has been deleted.

Returns:

an AuthenticationResult instance - this is currently ignored, so use only AuthenticationResult.OK.

checkRead

public AuthenticationResult checkRead(UserSession session,
 RTTPObject object,
 String requestedName)

Description copied from interface: Authenticator

This method will be called to check authentication every time a user tries to read an object.

Specified by:

checkRead in interface Authenticator

Parameters:

session - the user's session. This will be the same session object that is passed on the Authenticator.checkUser(com.caplin.server.auth.UserSession) call when the user logs in.

object - the RTTPObject the user is attempting to read.

requestedName - The subject that was requested by the user before any mappings got applied

Returns:

either AuthenticationResult.OK, AuthenticationResult.DENY or AuthenticationResult.AGAIN

checkWrite

public AuthenticationResult checkWrite(UserSession session,
 RTTPObject object,
 String requestedName,
 String contributionId,
 Map<String,String> fields)

Description copied from interface: Authenticator

This method will be called to check authentication every time a user attempts to create or write to an object.

Specified by:

checkWrite in interface Authenticator

Parameters:

session - the user's session. This will be the same session object that is passed on the Authenticator.checkUser(com.caplin.server.auth.UserSession) call when the user logs in.

object - the RTTPObject the user is attempting to read.

requestedName - The subject that was contributed to by the user before any mappings got applied

contributionId - the contribution Id that can be passed to the DelayedResultReceiver.delayedCheckWriteResult(com.caplin.server.auth.UserSession, com.caplin.server.auth.RTTPObject, java.lang.String, com.caplin.server.auth.AuthenticationResult) when a delayed result is required.

fields - a map containing field name/value pairs, present in the update being authenticated

Returns:

either AuthenticationResult.OK or AuthenticationResult.DENY or AuthenticationResult.DELAYED

You can only return {AuthenticationResult.DELAYED when the contributionId is non-null.

mapObject

public AuthenticationResult mapObject(UserSession session,
 MapObject mapObject)

Description copied from interface: Authenticator

This method will be called every time a user tries to read an object (before checkRead).

Provides a mechanism for mapping an object name on a per-user basis.

An Authenticator has the ability to map a user-requested object name to a different name in the server (and therefore at upstream DataSource(s) too). This can be useful for providing different data under the same symbol name to different users or groups of users, for example in order to provide preferential currency spreads to certain customers, or customised data for particular logins.

e.g. The user "U1" requests object "/OBJ1" and this is mapped here to "/OBJ1-U1". The user still sees the object as "/OBJ1", but the Liberator will request "/OBJ-U1" from the DataSource(s)

To use this functionality, the MapObject that is passed into this method should have it's mapped name set using the MapObject#setMappedName method. In addition, if mapping has occured, the return value should be AuthenticationResult.OK. The user-requested object name is available from the MapObject#getOriginalName method.

Alternatively, if the result may take some time to be established, the {AuthenticationResult.DELAYED return value may be used. This allows for Liberator processing to continue whilst the mapped name is retrieved, perhaps from an external service or database. After the mapping is decided, the DelayedResultReceiver#delayedMapObjectResult method should be called, passing the UserSession, MapObject and AuthenticationResult as parameters. N.B. It is valid, even after delaying the result, to return AuthenticationResult.FALSE if no mapping is to be performed

If the Authenticator is not providing mapping functionality then simply leave the MapObject unchanged and return the AuthenticationResult.FALSE result.

Specified by:

mapObject in interface Authenticator

Parameters:

session - the user's session. This will be the same session object that is passed on the Authenticator.checkUser(com.caplin.server.auth.UserSession) call when the user logs in.

mapObject - the object to be optionally mapped.

Returns:

either AuthenticationResult.FALSE if the object name has not been mapped, AuthenticationResult.OK if it has been mapped, or AuthenticationResult.DELAYED if the mapping is delayed.

See Also:

• DelayedResultReceiver.delayedMapObjectResult(UserSession, MapObject, AuthenticationResult)
• AuthenticationResult.DELAYED

requestObject

public AuthenticationResult requestObject(UserSession session,
 RTTPObject object)

Description copied from interface: Authenticator

This method will be called when a user's session becomes subscribed to an object.

A user session may become subscribed to the same object multiple times. In this case there will be multiple calls to this method and corresponding calls to discardObject for each discard the session performs

N.B. This method will be called after a successful checkRead call has completed

Specified by:

requestObject in interface Authenticator

Parameters:

session - the user's session. This will be the same session object that is passed on the Authenticator.checkUser(com.caplin.server.auth.UserSession) call when the user logs in.

object - the RTTPObject to which the user is now subscribed.

Returns:

an AuthenticationResult instance - this is currently ignored, so use only AuthenticationResult.OK.

discardObject

public AuthenticationResult discardObject(UserSession session,
 RTTPObject object)

Description copied from interface: Authenticator

This method will be called when a user's session is no longer subscribed to an object.

Specified by:

discardObject in interface Authenticator

Parameters:

session - the user's session. This will be the same session object that is passed on the Authenticator.checkUser(com.caplin.server.auth.UserSession) call when the user logs in.

object - the RTTPObject to which the user is no longer subscribed.

Returns:

an AuthenticationResult instance - this is currently ignored, so use only AuthenticationResult.OK.

authoriseHTTP

public AuthenticationResult authoriseHTTP(AuthenticationUser user)

Description copied from interface: Authenticator

This method will be called when an HTTP directory access authorisation is required.

Suitable HTTP directories must be configured in the Liberator before this method will be called.

As HTTP authorisation is a one-off event, no UserSession object is created, and an AuthenticationUser is passed directly.

Specified by:

authoriseHTTP in interface Authenticator

Parameters:

user - an AuthenticationUser containing the user name and password provided for HTTP directory access.

Returns:

either AuthenticationResult.OK or AuthenticationResult.DENY.

checkUpdate

public AuthenticationResult checkUpdate(UserSession session,
 RTTPObject object,
 String data)

Description copied from interface: Authenticator

Called on every update to an object (currently only news headline objects) to allow the Authenticator to authenticate each update based on content.

Allows an Authenticator to perform permissioning on news headlines / alerts. Can be useful where only certain content is to be sent to particular users or groups of users.

Specified by:

checkUpdate in interface Authenticator

Parameters:

session - the user's session. This will be the same session object that is passed on the Authenticator.checkUser(com.caplin.server.auth.UserSession) call when the user logs in.

object - the RTTPObject that has been updated (currently only news headline objects).

data - the content of the update to the object.

Returns:

either AuthenticationResult.OK or AuthenticationResult.DENY.

checkPermissionUpdate

public AuthenticationResult checkPermissionUpdate(UserSession session,
 RTTPObject object,
 String key,
 Map<String,String> fieldValues)

Description copied from interface: Authenticator

Called on every update to a permission object to allow the Authenticator to authenticate each update based on content.

Specified by:

checkPermissionUpdate in interface Authenticator

Parameters:

session - the user's session. This will be the same session object that is passed on the Authenticator.checkUser(com.caplin.server.auth.UserSession) call when the user logs in.

object - the RTTPObject that has been updated (currently only news headline objects).

key - The permission key that has been updated

fieldValues - The field/value pairs for this permission

Returns:

either AuthenticationResult.OK or AuthenticationResult.DENY.

globalPermissionUpdate

public void globalPermissionUpdate(RTTPObject object,
 String key,
 Map<String,String> fieldValues,
 PermissionUpdateType type)

Description copied from interface: Authenticator

Called on every update to a global permission object to allow the Authenticator to receive structured control messages.

Specified by:

globalPermissionUpdate in interface Authenticator

Parameters:

object - the RTTPObject that has been updated.

key - The permission key that has been updated

fieldValues - The field/value pairs for this permission

type - an enum value specifying the type of update.

shutdown

public void shutdown()

Description copied from interface: Authenticator

Called when the Liberator is shutting down.

Allows clean shutdown of connections, files and resources by the Authenticator.

Specified by:

shutdown in interface Authenticator