Java Maven project with BouncyCastle runtime error java.lang.NoClassDefFoundError

Question

I am new to Java and BouncyCastle and trying to get build a simple Java application to create a CSR using BouncyCastle. I performed following steps:

1. Create a Maven project using following command:

mvn archetype:generate -DgroupId=com.mycompany.app -DartifactId=my-bouncycastle-app -DarchetypeArtifactId=maven-archetype-quickstart -DarchetypeVersion=1.5 -DinteractiveMode=false

2. Add BouncyCastle dependencies to pom.xml.

<?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.mycompany.app</groupId>
  <artifactId>my-bouncycastle-app</artifactId>
  <version>1.0-SNAPSHOT</version>

  <name>my-bouncycastle-app</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.release>17</maven.compiler.release>
  </properties>

  <dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>org.junit</groupId>
        <artifactId>junit-bom</artifactId>
        <version>5.11.0</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
    </dependencies>
  </dependencyManagement>

  <dependencies>

    <dependency>
      <groupId>org.bouncycastle</groupId>
      <artifactId>bcpkix-jdk18on</artifactId>
      <version>1.79</version>
    </dependency>
    
    <dependency>
      <groupId>org.bouncycastle</groupId>
      <artifactId>bcprov-jdk18on</artifactId>
      <version>1.79</version>
    </dependency>


    <dependency>
      <groupId>org.junit.jupiter</groupId>
      <artifactId>junit-jupiter-api</artifactId>
      <scope>test</scope>
    </dependency>
    <!-- Optionally: parameterized tests support -->
    <dependency>
      <groupId>org.junit.jupiter</groupId>
      <artifactId>junit-jupiter-params</artifactId>
      <scope>test</scope>
    </dependency>
  </dependencies>

  <build>
    <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
      <plugins>
        <!-- clean lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#clean_Lifecycle -->
        <plugin>
          <artifactId>maven-clean-plugin</artifactId>
          <version>3.4.0</version>
        </plugin>
        <!-- default lifecycle, jar packaging: see https://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging -->
        <plugin>
          <artifactId>maven-resources-plugin</artifactId>
          <version>3.3.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>3.13.0</version>
        </plugin>
        <plugin>
          <artifactId>maven-surefire-plugin</artifactId>
          <version>3.3.0</version>
        </plugin>
        <plugin>
          <artifactId>maven-jar-plugin</artifactId>
          <version>3.4.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-install-plugin</artifactId>
          <version>3.1.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-deploy-plugin</artifactId>
          <version>3.1.2</version>
        </plugin>
        <!-- site lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#site_Lifecycle -->
        <plugin>
          <artifactId>maven-site-plugin</artifactId>
          <version>3.12.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-project-info-reports-plugin</artifactId>
          <version>3.6.1</version>
        </plugin>
      </plugins>
    </pluginManagement>
  </build>
</project>

3. Modified my main class.

package com.mycompany.app;

import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.Security;

import org.bouncycastle.jce.provider.BouncyCastleProvider;

/**
 * Hello world!
 */
public class App {
    public static void main(String[] args) {
        System.out.println("Start my BouncyCastle App");
        Security.setProperty("crypto.policy", "unlimited");
        Security.addProvider(new BouncyCastleProvider());
        KeyPairGenerator keyGen;
        try {
            keyGen = KeyPairGenerator.getInstance("RSA");
            keyGen.initialize(1024);
            KeyPair keyPair = keyGen.generateKeyPair();
            System.out.println("Public Key: " + keyPair.getPublic());
            System.out.println("Private Key: " + keyPair.getPrivate());
        } catch (NoSuchAlgorithmException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            System.exit(-1);
        }
        
    }
}

4. Build my package with "mvn clean package" command.

[INFO] Scanning for projects...
[INFO] 
[INFO] ---------------< com.mycompany.app:my-bouncycastle-app >----------------
[INFO] Building my-bouncycastle-app 1.0-SNAPSHOT
[INFO]   from pom.xml
[INFO] --------------------------------[ jar ]---------------------------------
[INFO] 
[INFO] --- clean:3.4.0:clean (default-clean) @ my-bouncycastle-app ---
[INFO] Deleting /Users/my-name/Java/Maven/my-bouncycastle-app/target
[INFO] 
[INFO] --- resources:3.3.1:resources (default-resources) @ my-bouncycastle-app ---
[INFO] skip non existing resourceDirectory /Users/my-name/Java/Maven/my-bouncycastle-app/src/main/resources
[INFO] 
[INFO] --- compiler:3.13.0:compile (default-compile) @ my-bouncycastle-app ---
[INFO] Recompiling the module because of changed source code.
[INFO] Compiling 1 source file with javac [debug release 17] to target/classes
[INFO] 
[INFO] --- resources:3.3.1:testResources (default-testResources) @ my-bouncycastle-app ---
[INFO] skip non existing resourceDirectory /Users/my-name/Java/Maven/my-bouncycastle-app/src/test/resources
[INFO] 
[INFO] --- compiler:3.13.0:testCompile (default-testCompile) @ my-bouncycastle-app ---
[INFO] Recompiling the module because of changed dependency.
[INFO] Compiling 1 source file with javac [debug release 17] to target/test-classes
[INFO] 
[INFO] --- surefire:3.3.0:test (default-test) @ my-bouncycastle-app ---
[INFO] Using auto detected provider org.apache.maven.surefire.junitplatform.JUnitPlatformProvider
[INFO] 
[INFO] -------------------------------------------------------
[INFO]  T E S T S
[INFO] -------------------------------------------------------
[INFO] Running com.mycompany.app.AppTest
[INFO] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.041 s -- in com.mycompany.app.AppTest
[INFO] 
[INFO] Results:
[INFO] 
[INFO] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0
[INFO] 
[INFO] 
[INFO] --- jar:3.4.2:jar (default-jar) @ my-bouncycastle-app ---
[INFO] Building jar: /Users/my-name/Java/Maven/my-bouncycastle-app/target/my-bouncycastle-app-1.0-SNAPSHOT.jar
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  2.576 s
[INFO] Finished at: 2024-11-20T14:58:58-06:00
[INFO] ------------------------------------------------------------------------

5. Execute my output .jar file.

% java -cp target/my-bouncycastle-app-1.0-SNAPSHOT.jar com.mycompany.app.App 
Error: Unable to initialize main class com.mycompany.app.App
Caused by: java.lang.NoClassDefFoundError: org/bouncycastle/jce/provider/BouncyCastleProvider

I am not sure what I am doing wrong here. Thanks for your help.

Edit: I am not(yet) trying to build a uber-jar file. I just want to get this application working. I can see bcpkix-jdk18on and bcprov-jdk18on were downloaded at ~/.m2/repository/org/bouncycastle. But I don't know why my execution failed. I've tried following:

% java -cp target/my-bouncycastle-app-1.0-SNAPSHOT.jar:~/.m2/repository/org/bouncycastle/bcprov-jdk18on/1.79/bcprov-jdk18on-1.79.jar com.mycompany.app.App 
Error: Unable to initialize main class com.mycompany.app.App
Caused by: java.lang.NoClassDefFoundError: org/bouncycastle/jce/provider/BouncyCastleProvider