com.pushtechnology.diffusion.client.security.authentication

Interface Authenticator

All Known Subinterfaces:

AuthenticationControl.ControlAuthenticator

public interface Authenticator

An authentication handler that processes authentication requests from the server.

Instances can be registered with the server using the AuthenticationControl feature.

The server calls an authentication handler when a client application creates a session, or changes the principal associated with a session, allowing the handler to veto individual requests.

Authentication handlers are configured in precedence order. Authentication will succeed if a handler responds by calling allow() or allow(Map) and handlers with higher precedence respond by calling abstain().

Authentication will fail if a handler responds by calling deny() and all higher precedence handlers respond by calling abstain().

If all authentication handlers respond by calling abstain(), the request will be denied. Once the outcome is known, the server can choose not to call any remaining authentication handlers.

Since:

6.2

Author:

DiffusionData Limited

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	Authenticator.Callback Single-use callback provided to the authenticate call.

Method Summary

Modifier and Type	Method and Description
void	authenticate(String principal, Credentials credentials, Map<String,String> sessionProperties, Map<String,String> proposedProperties, Authenticator.Callback callback) Processes an authentication request.

Method Detail

authenticate

void authenticate(String principal,
                  Credentials credentials,
                  Map<String,String> sessionProperties,
                  Map<String,String> proposedProperties,
                  Authenticator.Callback callback)

Processes an authentication request.

This method will be called to authenticate new sessions, and when a session requests that the session principal is changed (for example, using changePrincipal).

For each call to authenticate, the handler should respond by calling one of the methods of the provided callback. The handler can return immediately and process the authentication request asynchronously. The authentication will not proceed until a callback method is called.

The content of the sessionProperties parameter depends upon whether the authentication handler is being called on initial authentication of a session or as a result of a session re-authenticating using changePrincipal, as shown below:

	Initial Authentication	changePrincipal
Fixed Properties	A full set of fixed session properties as defined in Session. $Principal will be the same as the supplied principal. $Roles will contain the configured default roles for the principal.	A full set of fixed session properties as defined in Session. $Principal will be the principal from the previously authenticated session which can differ from the supplied principal. $Roles will contain the configured default roles for the new principal.
User-defined Properties	None	Existing user-defined properties

On initial authentication the proposedProperties parameter will provide any user-defined properties that the client supplied when opening the client session, but on re-authentication it will be empty

The handler can choose to call allow() to accept the authentication request with default behavior or allow(Map) to accept the authentication request with modifications to the session properties. Alternatively it can call deny() to deny the request or abstain() to abstain from authentication, in which case the request will be passed on to the next configured authentication handler.

If the handler calls allow() then the resulting session properties for the session will be as follows:

	Initial Authentication	changePrincipal
Fixed Properties	As supplied plus those assigned by the server on connection.	As supplied but with $Principal replaced by the supplied principal.
User-defined Properties	None	None

If the handler calls allow(Map) then the map can contain values for any fixed properties that can be changed/supplied (see below) and/or all user-defined properties to assign to the session. The user-defined properties can be those proposed by the client or any set of user-defined properties that the handler chooses.

Permitted fixed property adjustments

An authentication handler can set values for any of the following fixed properties to allow(Map):

• $Country
• $Language
• $Latitude
• $Longitude
• $Principal
• $Roles

An authentication handler can only set values of these fixed properties. Other fixed properties provided by the handler will be ignored. If the handler does not set a fixed property, the value will be as supplied, or as assigned by the server.

Handling the $Roles property

The $Roles property is formatted as a quoted list of strings. To make the handling of this property value easier there are methods on the Diffusion singleton. Using these methods an authenticator can adjust roles as follows:

 final Set<String> roles =
     Diffusion.stringToRoles(sessionProperties.get(Session.ROLES));
 ... changes roles are required ...
 sessionProperties.put(Session.ROLES, Diffusion.rolesToString(roles));
 callback.allow(sessionProperties);
 

Parameters:

principal - the name of the proposed principal, or ANONYMOUS if none was supplied

credentials - authenticating the principal; for example, a password

sessionProperties - supplies the currently known session properties for the client. On initial authentication this will be the known fixed property values. If the session is re-authenticating using changePrincipal, this will be the full set of fixed property values plus any user-defined properties from the existing session. Modifications made to this map by the authenticator are ignored unless the map is passed to the allow method.

proposedProperties - provides any user-defined properties proposed by the client. The handler can choose to pass on these properties as they are, veto some properties, or add more properties before passing them to the result. The client can provide arbitrary keys and values. Supplied properties should be checked and filtered/constrained to ensure they do not affect the integrity of the application. Authentication handlers should not blindly pass proposed properties to the allow method. Modifications made to this map by the authenticator are ignored unless the map is passed to the allow method.

callback - single use callback