Authpds

This gem provides a mechanism for authenticating via Ex Libris' Patron Directory Services (PDS) and provides hooks for making authorization decisions based on the user information provided by PDS. It leverages the authlogic gem and depends on a User-like model.

Basics

Generate User-like model:

rails generate model User username:string email:string firstname:string \ lastname:string mobile_phone:string crypted_password:string password_salt:string \ session_id:string persistence_token:string login_count:integer last_request_at:string \ current_login_at:string last_login_at:string last_login_ip:string current_login_ip:string \ user_attributes:text refreshed_at:datetime

Generate UserSession model

rails generate authlogic:session user_session

Create UserSessions controller

rails generate controller UserSessions –no-assets –no-helper

Mixin authpds methods into UserSessionsController

class UserSessionsController < ApplicationController require 'authpds'

include Authpds::Controllers::AuthpdsSessionsController

end

Mixin authpds methods into ApplicationController

class ApplicationController < ActionController::Base

protect_from_forgery
require 'authpds'
include Authpds::Controllers::AuthpdsController

end

Overview

The Authpds gem mixes in callbacks to Authlogic for persisting sessions based on a valid PDS handle.

The module extends Authlogic and should be compatible with Authlogic configuation. It also provides hooks for custom functionality. The documentation below describes the hooks available for overriding, PDS config methods and further details about the module.

Config Options Available

:pds_url

Base pds url

:calling_system

Name of the system

:anonymous

Does the system allow anonymous access?

:pds_attributes

Mapping of PDS attributes to record attributes

:redirect_logout_url

Custom redirect logout url

:login_inaccessible_url

Custom url to redirect to in case of system outage

:pds_record_identifier

PDS user method to call to identify record

:institution_param_key

Querystring parameter key for the institution value in this system

:validate_url_name

URL name for validation action in routes

Hooks Available for Overriding

:pds_record_identifier

Allows for more complex logic in determining what should be used as the record identifier.

Defaults to what was set in the pds_record_identifier config.

:valid_sso_session?

If there is no PDS handle, can we redirect to PDS to establish a SSO session based on some other information?

:additional_authorization

Allows for additions to the authorization decision

:additional_attributes

Allows for additional attributes to be stored in the record

:expiration_date

Indicates when the record information should be refreshed. Defaults to one week ago.

Further Implementation Details

Persisting a Session in AuthLogic

When persisting a Session, Authlogic attempts to create the Session based on information available without having to perform an actual login by calling the :persisting? method. Authologic provides several callbacks from the :persisting? method, e.g. :before_persisting, :persist, :after_persisting. We're using the :persist callback and setting it to :persist_session.

Access to the controller in Session

The class that Session extends, Authologic::Session::Base, has an explicit handle to the current controller via the instance method :controller. This gives our custom instance methods access to cookies, session information, loggers, etc. and also allows them to perform redirects and renders.

:before_login vs. :login_url

:before_login allows for customized processing before the SessionController invokes a redirect or render to a /login page. It is is fully generic and can be used for any custom purposes. :login_url is specific for the case of logging in from a remote sytem. The two methods can be used in conjuction, but any redirects or renders performed in :before_login, will supercede a redirect to :login_url.