Cas Spring-Boot Demo

This project is a Spring-Boot simple application where the login is authenticated by a CAS Server (Apereo Central Authentication Service). It includes the needed configuration to connect the client application to the Cas Server. The users allowed to log in are stored in a Postgres database, its properties are also exposed in this tutorial.

So for run the project you must have the server and the client running simultaneously

Prerequisites

The version used to run the projects are the following:

• Java 17.0.5
• Gradle 5.6.3

We need to deploy both server and client under HTTPS protocol due to the exchange of tickets and validation info made it must be under a secure protocol, for this reason we need to generate a key that will be used by them. We have to go to our pc root directory and find the etc folder, usually it is hidden, for showing it press CMD + SHIFT + . . Inside this folder we create a new one named cas. Once we have achived it we run the following command:

keytool -genkey -keyalg RSA -alias thekeystore -keystore thekeystore -storepass changeit -validity 360 -keysize 2048

In order for us not to have an SSL handshake error, we should type localhost as the value for first name, last name, organisatin name and organisation unit. Furthermore we have to import the keystore into de TDk we will be usin to run our client app with this command:

keytool -importkeystore -srckeystore thekeystore -destkeystore $JAVA_HOME/lib/security/cacerts

The password for the source and destination keystore is changeit. On Unix systems, we may have to run this command with admin (sudo) privilege. After importing, we should restart all instances of Java that's running or restart the system.

Make sure that this route is appropiate because if you are using JRE it may change.

Running a Spring Boot application with CAS Server 6

Clone the repository to your local machine using git clone https://github.com/wearearima/cas-spring-boot-demo.git

Start CAS Server

1. Copy the cas.properties and log4j2.xml files into your PC root folder /etc/cas/config. Those files are located on the project directory cas-spring-boot-demo/cas-server/etc/cas/config
2. Copy the casSecuredApp-8900.json file into your PC root folder /etc/cas/services. This file is located on the project directory cas-spring-boot-demo/cas-server/etc/cas/services.
3. Navigate to the server directory using cd cas-spring-boot-demo/tutorials/security-modules/cas/cas-server
4. Run the command ./gradlew run to start the CAS server. Your terminal should show this:

You could access to the server app via https://localhost:8443/cas

Start Spring-Boot Client

1. Go to cas-spring-boot-demo/spring-boot-client/src/main/com/example/springbootclient directory, you will find the SpringBootClientApplication.java .file. Depending on your IDE you could double click it and choose the Run Java java option or a play icon would appear on the right upper corner of your screen.
2. You could access to the client app via https://localhost:8900.

So now, you will be able to go to the spring-boot application, click on Login and it will redirect you to the Cas-Server app, this means the client is registred properly on the Cas Server.

Understanding the configuration

PostgreSQL Database

In order to store the users we have two options for testing the app, the first one is the simplest, because we only have to replace in our cas.properties file, all the database configuration for this line: cas.authn.accept.users=username::password. That username and password will be valid credentials to access to our application.

If we want to go further, we can create a database to store them. In order to do that, move to postgresql dictory and run a postgresql database with the following commands:

cd cas-spring-boot-demo/postgresql/
docker-compose up

Once the database has started, we are going to create the table users and populate it with some users.

Choose the IDE you prefer, or intall DBeaver database tool and execute this query:

CREATE TABLE users
(
    id bigint NOT NULL,
    disabled boolean,
    email character varying(40) COLLATE pg_catalog."default",
    first_name character varying(40) COLLATE pg_catalog."default",
    last_name character varying(40) COLLATE pg_catalog."default",
    expired boolean,
    password character varying(100) COLLATE pg_catalog."default",
    CONSTRAINT users_pkey PRIMARY KEY (id),
    CONSTRAINT uk6dotkott2kjsp8vw4d0m25fb7 UNIQUE (email)
)
WITH (
    OIDS = FALSE
);

That will create the table and now we insert the user:

INSERT INTO users(
 id, disabled, email, first_name, last_name, expired, password)
 VALUES (1, false, 'user1@test.com', 'test', 'user1', false, '$2y$12$7XQUDwK3QE7oBB0wmVpht.aT7gESI205SgWarj15Wz2Jt6OfglbQ.');

The password is encoded by bcryp algorithm.

Now you can login with the test user:

1. Go to https://localhost:8900.
2. Click on login url, it should redirect you to the cas server login form.
3. Use ‘user1@test.com’ as username and ‘testpass’ as password, you should be redirected to the secured page.
4. Now you can logout if wished.

Cas Server Configuration

Directory: /tutorials/security-modules/cas/cas-server

There are differents ways to register an application; YAML, JSON, MongoDB, LDAP and go on. We have chosen via JSON, this file is inside the cas-server folder in the /etc/cas/services directory. The property which is outstanding for us is the serviceId, this URL is the entry point for client application into the server.

Then, we have to copy this file in our PC root directory etc/cas/services therefore we create the services folder.

The file where is all the magic is the cas.properties one, we can find it in the /etc/cas/config directory, here we specified the server name, where we have thekeystore, its password and where or who are the users that have permissions to log in our application. We will go to that with the database section. So, in our PC root directory /etc/cas/ we must create the config folder and locate this cas.properties file and also the log4j2.xml that is in the same folder. Do not worry if you change them because when running with the ./gradlew clean copyCasConfiguration build run command it will refresh those files.

For deploying the app under HTTPS protocol, in our application.properties file we have added the location of thekeystore we generated previously.

Spring Boot Configuration

Directory: /tutorials/security-modules/cas/cas-secured-app

The configuration we have made to register this application to the CAS Server is mainly in the CasSecuredApplication.java class. If we look into it, we can notice that there are several methods with the @Bean annotation, well this is for the login and logout authentication. Its important that the ServiceProperties method, when we set the service, the URL we pass it as a parameter must match with the URL of the serviceId propertie on our JSON file in the server.