unlegitlibrary/README.MD

UnlegitLibrary

Overview

UnlegitLibrary is a general-purpose Java utility library that bundles a modular event system, command framework, addon loader, networking (TCP/UDP with optional TLS), and a wide set of math/number/string/file/reflection helpers.

Modules

• Addon system: loader + lifecycle events
• Event system: listeners, priorities, cancellable events
• Command system: command manager, permissions, execution events
• Network system: TCP/UDP transport, packet handling, optional TLS, UDP encryption
• Utilities: math/number helpers, strings, colors, files, reflection, logging
• Argument parsing: register arguments, validate values, run callbacks

ArgumentParser

Basic usage

ArgumentParser parser = new ArgumentParser(args);

Argument verbose = new Argument("verbose", "Enable verbose output", false);
verbose.setRun((arg, value) -> System.out.println("Verbose on"));
parser.registerArgument(verbose);

Argument mode = new Argument("mode", "Run mode", true, true, false, List.of("dev", "prod"));
mode.setRun((arg, value) -> System.out.println("Mode: " + value.orElse("")));
parser.registerArgument(mode);

parser.runArguments();

Value rules

• Constructor: Argument(name, description, required, requireValue, optionalValue, values)
• requireValue=false and optionalValue=false: argument has no value
• requireValue=true and optionalValue=false: value must be present
• requireValue=false and optionalValue=true: value is optional
• requireValue=true and optionalValue=true is not allowed
• If values is not empty, the provided value must be in that list

License Information

GNU General Public License v3.0 (GPLv3)
The default license. Applies to all users, projects, and distributions unless explicitly stated otherwise.
-> https://repo.unlegitdqrk.dev/UnlegitDqrk/UnlegitLibrary/src/LICENSE

Open Autonomous Public License (OAPL)
A special exception applies exclusively to the project Open Autonomous Connection (OAC).
Within OAC, the UnlegitLibrary is also licensed under the OAPL.
In this context, OAPL terms take precedence.
-> https://repo.open-autonomous-connection.org/Open-Autonomous-Connection/OAPL

Include in own projects

<repositories>
    <repository>
        <id>repounlegitdqrk</id>
        <url>https://repo.unlegitdqrk.dev/api/packages/unlegitdqrk/maven</url>
        <snapshots>
            <enabled>true</enabled>
        </snapshots>
    </repository>
</repositories>
<dependencies>
    <dependency>
        <groupId>dev.unlegitdqrk</groupId>
        <artifactId>unlegitlibrary</artifactId>
        <version>VERSION</version>
    </dependency>
</dependencies>

NetworkSystem (TCP/UDP + TLS)

• TCP is the control channel (handshake, packet routing).
• UDP is optional and encrypted with a symmetric key negotiated over TCP.
• TLS can be enabled or disabled. For TLS, configure KeyStore/TrustStore explicitly.
• mTLS is supported: set client auth mode to REQUIRED and provide a TrustStore on the server.

Basic usage

PacketHandler packetHandler = new PacketHandler();
packetHandler.registerPacket(() -> new ExamplePacket(""));

NetworkServer server = new NetworkServer(packetHandler);
server.configureSSL(false, ClientAuthMode.NONE);
server.start(25565, 25566);

NetworkClient client = new NetworkClient(packetHandler);
client.configureSSL(false);
client.connect("127.0.0.1", 25565);

TLS with TrustStore (server validation)

KeyStore serverKeyStore = loadStore("certs/server.p12", "changeit".toCharArray());
KeyStore clientTrustStore = loadStore("certs/client-trust.p12", "changeit".toCharArray());

NetworkServer server = new NetworkServer(packetHandler);
server.configureSSL(true, ClientAuthMode.NONE, serverKeyStore, "changeit".toCharArray(), null);
server.start(25565, 25566);

NetworkClient client = new NetworkClient(packetHandler);
client.configureSSL(true, null, null, clientTrustStore);
client.connect("127.0.0.1", 25565);

TLS with Client Certificate (mTLS)

KeyStore serverKeyStore = loadStore("certs/server.p12", "changeit".toCharArray());
KeyStore serverTrustStore = loadStore("certs/server-trust.p12", "changeit".toCharArray());
KeyStore clientKeyStore = loadStore("certs/client.p12", "changeit".toCharArray());
KeyStore clientTrustStore = loadStore("certs/client-trust.p12", "changeit".toCharArray());

NetworkServer server = new NetworkServer(packetHandler);
server.configureSSL(true, ClientAuthMode.REQUIRED, serverKeyStore, "changeit".toCharArray(), serverTrustStore);
server.start(25565, 25566);

NetworkClient client = new NetworkClient(packetHandler);
client.configureSSL(true, clientKeyStore, "changeit".toCharArray(), clientTrustStore);
client.connect("127.0.0.1", 25565);

Certificate generation for NetworkSystem

Creating Root-CA:

openssl genrsa -out myCA.key 4096
openssl req -x509 -new -nodes -key myCA.key -sha256 -days 3650 -out myCA.pem

myCA.key = private Key for CA (keep secret)
myCA.pem = public Root-Certificate for signing server and client certificates

Creating Server Certificate based on Root-CA:

openssl genrsa -out server.key 2048
openssl req -new -key server.key -out server.csr
openssl x509 -req -in server.csr -CA myCA.pem -CAkey myCA.key -CAcreateserial -out server.crt -days 825 -sha256

server.key = private Key for Server
server.crt = Server-Certificate signed by Root-CA

Optional: Creating Client Certificate based on Root-CA:

openssl genrsa -out client.key 2048
openssl req -new -key client.key -out client.csr
openssl x509 -req -in client.csr -CA myCA.pem -CAkey myCA.key -CAcreateserial -out client.crt -days 825 -sha256

client.key = private Key for Client
client.crt = Client-Certificate signed by Root-CA

1. Generate a Root-CA. Every client and server NEED this Root-CA *.pem-File. Keep the *.key file private
   
2. Generate a Server-Certificate
3. Optional: Generate a Client-Certificate
4. Put the Root-CA on your server and client in "certificates/ca"-Folder
5. Put the Server-Certificate-Key in "certificates/key"-Folder
6. Put the Server-Certificate in "certificates/server"-Folder
7. Optional: Put the Client-Certificate-Key in "certificates/key"-Folder
8. Optional: Put the Client-Certificate in "certificates/client"-Folder

Helper: load PKCS12 stores in Java

private static KeyStore loadStore(String path, char[] password) throws Exception {
    KeyStore store = KeyStore.getInstance("PKCS12");
    try (FileInputStream in = new FileInputStream(path)) {
        store.load(in, password);
    }
    return store;
}