Authentication in JSF2 with JAAS: Part 2 – Authenticating a client/user

Dominik Dorn — Thu, 25 Feb 2010 11:28:04 +0000

In the second part of this series, we are going to understand some more terminology of JAAS and start creating our own authentication system.

A LoginContext Object is used by applications to authenticate users independently of the underlying authentication technology. Authentication technology in this context means stuff like “file based authentication”, “Database based authentication”, “LDAP authentication”, “CERTIFICATE authentication” and so on.

The LoginContext class is part of the javax.security.auth.login package and describes methods used to authenticate Subjects/user in the meaning of Part 1 of this series). The documentation states:

A subject is an identity in a system that you want to authenticate and assign access rights to. A subject can be a human user, a process, or a machine..

which is basically what I said before. Its still a little bit unclear to me, why they use “user” in one documentation and “subject” in the other, but as its the same thing, we know what to do.

The documentation further states, that a subject may interact with different authorities (applications) and may have different passwords (credentials) for each of them. To represent the subject/user in these applications, the java.security.Principal class is used.

Our own LoginContext now invokes various LoginModules ( these handle the different ways of authentication, like form based, HTTP-Basic, HTTP-Digest, etc.). The LoginModule interface is part of
the javax.security.auth.spi package. If one ever wants to integrate Facebook connect or something similar, this is where to look at!

But how does the LoginContext know, which LoginModules to invoke? This is done by a Configuration Object.

So, to sum this up:

We have 1-n LoginModules, handling different form of authentication.. file, db, ldap and so on
We have a LoginContext, taking users credentials and supplying them to the LoginModules
We have configurations, specifying which LoginModules should be used by the LoginContext
A client supplies its credentials to the LoginContext. The LoginContext looks up, which LoginModules to use in its Configuration and authenticates the client with the provided credentials against the LoginModules.

But why bother with all this stuff of LoginContext, LoginModules, Configuration and so on? Shouldn’t it be easy to use authentication, especially custom authentication in a web-app?

Because we’ve already got it in our AppServer!

Configuration:
We’re actually creating our Configuration object manually in our web.xml.

Here we define, how we gain the authentication data from the user. In this example, I used auth-method=FORM because no-one wants to use HTTP-Basic Authentication anymore today!

    
        FORM
        nameOfTheRealm

/login.xhtml
/loginError.xhtml

With this configuration, you can already create your own login form with your preferred style, like this:
login.xhtml


Userid

Password

In the next part of the series, we’ll see how you can do it with an jsf/facelets page.

Ok, we now got our form for login. To Logout simply make a link to /j_security_logout

We’ve now got login + logout, but they are not working yet. What we still have to do, is specify, what we’re authenticating against. In this post, we called it LoginModule, in Glassfishv3 its called Realm and we have already
configured it with our Login-Config above.

A post which explains how to configure the simply, build in Glassfish “File-Realm” is available at DevelopInJava.com.

In the next blog entry of this series, we’ll see how we can create our own realm, that really suits our needs.

We now got everything needed for a basic authentication, but we don’t yet have a group to role mapping, which we need for stuff like #{request.isUserInRole(‘ADMIN’)} or annotating our beans (see later for all of that).
So what we’re going to do is, map the given “groups” to roles. Before we do that, we should tell our application, which roles we have. Do it like that in your web.xml

    
        all the users with the role Admin

Authentication in JSF2 with JAAS: Part 1 – Understand the terminology

Dominik Dorn — Wed, 24 Feb 2010 23:02:12 +0000

Ok, this will be a multi-part blog entry series.
What I want to do with this blog entries, is to document, how to make your JSF2 application use JAAS ( Java Authentication and Authorization Service ) to manage your/my users, authenticate them through a form with
the help of the server and use that security information in our JSF2 pages and our Java Beans.

In this first part of the series, I’ll try to cover the terminology used in easy to understand words.

These are the terms, you’ll need to know:

realm: A realm is basically a "user database", being it a flat file with user/pass + group info, database tables or even an ldap directory or something else you can imagine, like facebook connect or google authentication system. It may be used by n applications.
user: A user is a person or program wishing to authenticate against our server/app. If you only make your website for real persons, these are your users. If you also offer a webservice, other programs accessing that service are also users. A user belongs to a realm, so may be valid in n applications (see principal below)
role: Roles are assigned to users and/or groups in an application. E.g. GUEST for a not authenticated visitor, LOGGEDIN_USER for an authenticated user, MODERATOR or ADMIN for special people.
group: Groups are like roles, but they are used over multiple applications and mapped to specific ROLES on an per-application-basis
principal: A Principal is an authenticated user in the scope of an application. The same user may have different principals in different applications. A principal is identified by its name and authenticated using authentication data (credentials)
security policy domain: Also called security domain or realm. Basically, the database where you lookup users. But in this meaning, its where the realms are used, being it application1, application2, applicationN
Security attributes: are attributes associated with every principal, like " is allowed to access the admin area" or stuff like that.
credential: contains or references security attributes; are used to authenticate a Principal for a Java EE product service (your webapp)

If you want to get the original documentation, take a look at the Security chapter in the Java EE 6 Tutorial Volume I

Further references, which I’ll probably be using in the next posts of these series:

dominikdorn.com » JAAS

Authentication in JSF2 with JAAS: Part 2 – Authenticating a client/user

Authentication in JSF2 with JAAS: Part 1 – Understand the terminology