Chapter 2. Securing management interfaces and applications

Procedure

1. Set up a Maven project using the mvn command. The command creates the directory structure for the project and the pom.xml configuration file.

   Syntax

   $ mvn archetype:generate \
   -DgroupId=${group-to-which-your-application-belongs} \
   -DartifactId=${name-of-your-application} \
   -DarchetypeGroupId=org.apache.maven.archetypes \
   -DarchetypeArtifactId=maven-archetype-webapp \
   -DinteractiveMode=false

   Example

   $ mvn archetype:generate \
   -DgroupId=com.example.app \
   -DartifactId=simple-webapp-example \
   -DarchetypeGroupId=org.apache.maven.archetypes \
   -DarchetypeArtifactId=maven-archetype-webapp \
   -DinteractiveMode=false

2. Navigate to the application root directory:

   Syntax

   $ cd <name-of-your-application>

   Example

   $ cd simple-webapp-example

3. Replace the content of the generated pom.xml file with the following text:

   <?xml version="1.0" encoding="UTF-8"?>
   
   <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
   
     <groupId>com.example.app</groupId>
     <artifactId>simple-webapp-example</artifactId>
     <version>1.0-SNAPSHOT</version>
     <packaging>war</packaging>
   
     <name>simple-webapp-example Maven Webapp</name>
     <!-- FIXME change it to the project's website -->
     <url>http://www.example.com</url>
   
     <properties>
       <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
       <maven.compiler.source>11</maven.compiler.source>
       <maven.compiler.target>11</maven.compiler.target>
     </properties>
   
     <dependencies>
       <dependency>
         <groupId>jakarta.servlet</groupId>
         <artifactId>jakarta.servlet-api</artifactId>
         <version>6.0.0</version>
         <scope>provided</scope>
       </dependency>
       <dependency>
         <groupId>org.wildfly.security</groupId>
         <artifactId>wildfly-elytron-auth-server</artifactId>
         <version>1.19.0.Final</version>
       </dependency>
     </dependencies>
   
     <build>
       <finalName>${project.artifactId}</finalName>
       <plugins>
         <plugin>
           <groupId>org.wildfly.plugins</groupId>
           <artifactId>wildfly-maven-plugin</artifactId>
           <version>2.1.0.Final</version>
         </plugin>
       </plugins>
     </build>
   
   </project>

Procedure

1. Create a directory to store the Java files.

   Syntax

   $ mkdir -p src/main/java/<path_based_on_artifactID>

   Example

   $ mkdir -p src/main/java/com/example/app

2. Navigate to the new directory.

   Syntax

   $ cd src/main/java/<path_based_on_artifactID>

   Example

   $ cd src/main/java/com/example/app

3. Create a file SecuredServlet.java with the following content:

   package com.example.app;
   
   import java.io.IOException;
   import java.io.PrintWriter;
   import java.security.Principal;
   import java.util.ArrayList;
   import java.util.Collection;
   import java.util.Iterator;
   import java.util.List;
   import java.util.Set;
   
   import jakarta.servlet.ServletException;
   import jakarta.servlet.annotation.WebServlet;
   import jakarta.servlet.http.HttpServlet;
   import jakarta.servlet.http.HttpServletRequest;
   import jakarta.servlet.http.HttpServletResponse;
   import org.wildfly.security.auth.server.SecurityDomain;
   import org.wildfly.security.auth.server.SecurityIdentity;
   import org.wildfly.security.authz.Attributes;
   import org.wildfly.security.authz.Attributes.Entry;
   /**
    * A simple secured HTTP servlet. It returns the user name and
    * attributes obtained from the logged-in user's Principal. If
    * there is no logged-in user, it returns the text
    * "NO AUTHENTICATED USER".
    */
   
   @WebServlet("/secured")
   public class SecuredServlet extends HttpServlet {
   
       @Override
       protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
           try (PrintWriter writer = resp.getWriter()) {
   
           	Principal user = req.getUserPrincipal();
           	SecurityIdentity identity = SecurityDomain.getCurrent().getCurrentSecurityIdentity();
           	Attributes identityAttributes = identity.getAttributes();
           	Set <String> keys = identityAttributes.keySet();
           	String attributes = "<ul>";
   
           	for (String attr : keys) {
           		attributes += "<li> " +  attr + " : " + identityAttributes.get(attr).toString() + "</li>";
           	}
   
           	attributes+="</ul>";
           	writer.println("<html>");
           	writer.println("  <head><title>Secured Servlet</title></head>");
           	writer.println("  <body>");
           	writer.println("    <h1>Secured Servlet</h1>");
           	writer.println("    <p>");
           	writer.print(" Current Principal '");
           	writer.print(user != null ? user.getName() : "NO AUTHENTICATED USER");
           	writer.print("'");
           	writer.print(user != null ? "\n" + attributes : "");
           	writer.println("    </p>");
           	writer.println("  </body>");
           	writer.println("</html>");
           }
       }
   
   }

4. In the application root directory, compile your application with the following command:

   $ mvn package
   ...
   [INFO] ------------------------------------------------------------------------
   [INFO] BUILD SUCCESS
   [INFO] ------------------------------------------------------------------------
   [INFO] Total time: 1.015 s
   [INFO] Finished at: 2022-04-28T17:48:53+05:30
   [INFO] ------------------------------------------------------------------------

5. Deploy the application.

   $ mvn wildfly:deploy