Add configuration option to kick players when toggling premium state

Fixes #1285

README.md

@@ -1,5 +1,7 @@
 # FastLogin
 
+![A shield-shaped emblem with a bold lightning bolt on the left, resembling Minecraft blocks. To the right, "FastLogin" is written in teal, with the tagline: "Automatically detect and login premium Minecraft players"](https://github.com/user-attachments/assets/0788ef69-029b-465e-83a2-b8e7bccc6295 "FastLogin project logo.avif")
+
 Checks if a Minecraft player has a paid account (premium). If so, they can skip offline authentication (auth plugins).
 So they don't need to enter passwords. This is also called auto login (auto-login).
 

bukkit/src/main/java/com/github/games647/fastlogin/bukkit/command/CrackedCommand.java

@@ -30,6 +30,7 @@ import com.github.games647.fastlogin.bukkit.event.BukkitFastLoginPremiumToggleEv
 import com.github.games647.fastlogin.core.storage.StoredProfile;
 import org.bukkit.command.Command;
 import org.bukkit.command.CommandSender;
+import org.bukkit.entity.Player;
 import org.jetbrains.annotations.NotNull;
 
 import static com.github.games647.fastlogin.core.shared.event.FastLoginPremiumToggleEvent.PremiumToggleReason;
@@ -57,6 +58,7 @@ public class CrackedCommand extends ToggleCommand {
             return;
         }
 
+        Player player = (Player) sender;
         if (forwardCrackedCommand(sender, sender.getName())) {
             return;
         }
@@ -71,7 +73,16 @@ public class CrackedCommand extends ToggleCommand {
             plugin.getScheduler().runAsync(() -> {
                 plugin.getCore().getStorage().save(profile);
                 plugin.getServer().getPluginManager().callEvent(
-                        new BukkitFastLoginPremiumToggleEvent(profile, PremiumToggleReason.COMMAND_OTHER));
+                        new BukkitFastLoginPremiumToggleEvent(sender, profile, PremiumToggleReason.COMMAND_OTHER)
+                );
+
+                plugin.getScheduler().getSyncExecutor().execute(() -> {
+                    if (plugin.getCore().getConfig().getBoolean("kick-toggle", true)) {
+                        player.kickPlayer(plugin.getCore().getMessage("remove-premium"));
+                    } else {
+                        plugin.getCore().sendLocaleMessage("add-premium", sender);
+                    }
+                });
             });
         } else {
             plugin.getCore().sendLocaleMessage("not-premium", sender);
@@ -104,7 +115,7 @@ public class CrackedCommand extends ToggleCommand {
             plugin.getScheduler().runAsync(() -> {
                 plugin.getCore().getStorage().save(profile);
                 plugin.getServer().getPluginManager().callEvent(
-                        new BukkitFastLoginPremiumToggleEvent(profile, PremiumToggleReason.COMMAND_OTHER));
+                        new BukkitFastLoginPremiumToggleEvent(sender, profile, PremiumToggleReason.COMMAND_OTHER));
             });
         }
     }

bukkit/src/main/java/com/github/games647/fastlogin/bukkit/command/PremiumCommand.java

@@ -68,7 +68,8 @@ public class PremiumCommand extends ToggleCommand {
             return;
         }
 
-        UUID id = ((Player) sender).getUniqueId();
+        Player player = (Player) sender;
+        UUID id = player.getUniqueId();
         if (plugin.getConfig().getBoolean("premium-warning") && !plugin.getCore().getPendingConfirms().contains(id)) {
             sender.sendMessage(plugin.getCore().getMessage("premium-warning"));
             plugin.getCore().getPendingConfirms().add(id);
@@ -86,10 +87,17 @@ public class PremiumCommand extends ToggleCommand {
             plugin.getScheduler().runAsync(() -> {
                 plugin.getCore().getStorage().save(profile);
                 plugin.getServer().getPluginManager().callEvent(
-                        new BukkitFastLoginPremiumToggleEvent(profile, PremiumToggleReason.COMMAND_SELF));
-            });
+                        new BukkitFastLoginPremiumToggleEvent(sender, profile, PremiumToggleReason.COMMAND_SELF)
+                );
 
-            plugin.getCore().sendLocaleMessage("add-premium", sender);
+                plugin.getScheduler().getSyncExecutor().execute(() -> {
+                    if (plugin.getCore().getConfig().getBoolean("kick-toggle", true)) {
+                        player.kickPlayer(plugin.getCore().getMessage("remove-premium"));
+                    } else {
+                        plugin.getCore().sendLocaleMessage("add-premium", sender);
+                    }
+                });
+            });
         }
     }
 
@@ -117,7 +125,8 @@ public class PremiumCommand extends ToggleCommand {
             plugin.getScheduler().runAsync(() -> {
                 plugin.getCore().getStorage().save(profile);
                 plugin.getServer().getPluginManager().callEvent(
-                        new BukkitFastLoginPremiumToggleEvent(profile, PremiumToggleReason.COMMAND_OTHER));
+                        new BukkitFastLoginPremiumToggleEvent(sender, profile, PremiumToggleReason.COMMAND_OTHER)
+                );
             });
 
             plugin.getCore().sendLocaleMessage("add-premium-other", sender);

bukkit/src/main/java/com/github/games647/fastlogin/bukkit/event/BukkitFastLoginPremiumToggleEvent.java

@@ -27,6 +27,7 @@ package com.github.games647.fastlogin.bukkit.event;
 
 import com.github.games647.fastlogin.core.shared.event.FastLoginPremiumToggleEvent;
 import com.github.games647.fastlogin.core.storage.StoredProfile;
+import org.bukkit.command.CommandSender;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
 import org.jetbrains.annotations.NotNull;
@@ -34,11 +35,15 @@ import org.jetbrains.annotations.NotNull;
 public class BukkitFastLoginPremiumToggleEvent extends Event implements FastLoginPremiumToggleEvent {
 
     private static final HandlerList HANDLERS = new HandlerList();
+
+    private final CommandSender invoker;
     private final StoredProfile profile;
     private final PremiumToggleReason reason;
 
-    public BukkitFastLoginPremiumToggleEvent(StoredProfile profile, PremiumToggleReason reason) {
+    public BukkitFastLoginPremiumToggleEvent(CommandSender invoker, StoredProfile profile, PremiumToggleReason reason) {
         super(true);
+
+        this.invoker = invoker;
         this.profile = profile;
         this.reason = reason;
     }
@@ -48,6 +53,13 @@ public class BukkitFastLoginPremiumToggleEvent extends Event implements FastLogi
         return profile;
     }
 
+    /**
+     * @return who triggered this change. This could be a Player for itself or others (Admin) or the console.
+     */
+    public CommandSender getInvoker() {
+        return invoker;
+    }
+
     @Override
     public PremiumToggleReason getReason() {
         return reason;

bukkit/src/main/java/com/github/games647/fastlogin/bukkit/listener/protocollib/EncryptionUtil.java

@@ -31,7 +31,6 @@ import com.google.common.hash.Hasher;
 import com.google.common.hash.Hashing;
 import com.google.common.io.Resources;
 import com.google.common.primitives.Longs;
-import lombok.val;
 
 import javax.crypto.BadPaddingException;
 import javax.crypto.Cipher;
@@ -41,6 +40,7 @@ import javax.crypto.SecretKey;
 import javax.crypto.spec.SecretKeySpec;
 import java.io.IOException;
 import java.math.BigInteger;
+import java.net.URL;
 import java.nio.ByteBuffer;
 import java.nio.charset.StandardCharsets;
 import java.security.InvalidKeyException;
@@ -53,6 +53,7 @@ import java.security.PublicKey;
 import java.security.Signature;
 import java.security.SignatureException;
 import java.security.spec.InvalidKeySpecException;
+import java.security.spec.KeySpec;
 import java.security.spec.X509EncodedKeySpec;
 import java.time.Instant;
 import java.util.Arrays;
@@ -198,9 +199,9 @@ final class EncryptionUtil {
 
     private static PublicKey loadMojangSessionKey()
             throws IOException, NoSuchAlgorithmException, InvalidKeySpecException {
-        val keyUrl = FastLoginBukkit.class.getClassLoader().getResource("yggdrasil_session_pubkey.der");
-        val keyData = Resources.toByteArray(keyUrl);
-        val keySpec = new X509EncodedKeySpec(keyData);
+        URL keyUrl = FastLoginBukkit.class.getClassLoader().getResource("yggdrasil_session_pubkey.der");
+        byte[] keyData = Resources.toByteArray(keyUrl);
+        KeySpec keySpec = new X509EncodedKeySpec(keyData);
 
         return KeyFactory.getInstance("RSA").generatePublic(keySpec);
     }

bukkit/src/main/java/com/github/games647/fastlogin/bukkit/listener/protocollib/ProtocolLibListener.java

@@ -39,6 +39,7 @@ import com.comphenix.protocol.utility.MinecraftVersion;
 import com.comphenix.protocol.wrappers.BukkitConverters;
 import com.comphenix.protocol.wrappers.Converters;
 import com.comphenix.protocol.wrappers.WrappedGameProfile;
+import com.comphenix.protocol.wrappers.WrappedProfilePublicKey.WrappedProfileKeyData;
 import com.github.games647.fastlogin.bukkit.BukkitLoginSession;
 import com.github.games647.fastlogin.bukkit.FastLoginBukkit;
 import com.github.games647.fastlogin.bukkit.listener.protocollib.packet.ClientPublicKey;
@@ -48,7 +49,6 @@ import com.mojang.datafixers.util.Either;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandler;
 import io.netty.util.AttributeKey;
-import lombok.val;
 import org.bukkit.entity.Player;
 import org.geysermc.floodgate.api.player.FloodgatePlayer;
 import org.jetbrains.annotations.NotNull;
@@ -245,8 +245,9 @@ public class ProtocolLibListener extends PacketAdapter {
             // public key is sent separate
             clientKey = Optional.empty();
         } else {
-            val profileKey = packet.getOptionals(BukkitConverters.getWrappedPublicKeyDataConverter())
-                    .optionRead(0);
+            Optional<Optional<WrappedProfileKeyData>> profileKey = packet.getOptionals(
+                            BukkitConverters.getWrappedPublicKeyDataConverter()
+                    ).optionRead(0);
 
             clientKey = profileKey.flatMap(Function.identity()).flatMap(data -> {
                 Instant expires = data.getExpireTime();

bukkit/src/main/java/com/github/games647/fastlogin/bukkit/listener/protocollib/VerifyResponseTask.java

@@ -50,7 +50,6 @@ import com.github.games647.fastlogin.bukkit.BukkitLoginSession;
 import com.github.games647.fastlogin.bukkit.FastLoginBukkit;
 import com.github.games647.fastlogin.bukkit.InetUtils;
 import com.github.games647.fastlogin.bukkit.listener.protocollib.packet.ClientPublicKey;
-import lombok.val;
 import org.bukkit.entity.Player;
 
 import javax.crypto.Cipher;
@@ -307,7 +306,7 @@ public class VerifyResponseTask implements Runnable {
             startPacket.getStrings().write(0, username);
 
             EquivalentConverter<WrappedProfileKeyData> converter = BukkitConverters.getWrappedPublicKeyDataConverter();
-            val wrappedKey = Optional.ofNullable(clientKey).map(key ->
+            Optional<WrappedProfileKeyData> wrappedKey = Optional.ofNullable(clientKey).map(key ->
                     new WrappedProfileKeyData(clientKey.expiry(), clientKey.key(), clientKey.signature())
             );
 

bukkit/src/main/java/com/github/games647/fastlogin/bukkit/listener/protocollib/packet/ClientPublicKey.java

@@ -25,20 +25,38 @@
  */
 package com.github.games647.fastlogin.bukkit.listener.protocollib.packet;
 
-import lombok.Value;
-import lombok.experimental.Accessors;
-
 import java.security.PublicKey;
 import java.time.Instant;
 import java.util.Base64;
 import java.util.StringJoiner;
 
-@Accessors(fluent = true)
-@Value(staticConstructor = "of")
 public class ClientPublicKey {
-    Instant expiry;
-    PublicKey key;
-    byte[] signature;
+
+    private final Instant expiry;
+    private final PublicKey key;
+    private final byte[] signature;
+
+    public Instant expiry() {
+        return expiry;
+    }
+
+    public PublicKey key() {
+        return key;
+    }
+
+    public byte[] signature() {
+        return signature;
+    }
+
+    public ClientPublicKey(Instant expiry, PublicKey key, byte[] signature) {
+        this.expiry = expiry;
+        this.key = key;
+        this.signature = signature;
+    }
+
+    public static ClientPublicKey of(Instant expiry, PublicKey key, byte[] signature) {
+        return new ClientPublicKey(expiry, key, signature);
+    }
 
     public boolean isExpired(Instant verifyTimestamp) {
         return !verifyTimestamp.isBefore(expiry);

bukkit/src/test/java/com/github/games647/fastlogin/bukkit/FastLoginBukkitTest.java

@@ -26,7 +26,7 @@
 package com.github.games647.fastlogin.bukkit;
 
 import com.github.games647.fastlogin.core.CommonUtil;
-import lombok.val;
+import net.md_5.bungee.api.chat.BaseComponent;
 import net.md_5.bungee.api.chat.TextComponent;
 import net.md_5.bungee.chat.ComponentSerializer;
 import org.junit.jupiter.api.Test;
@@ -37,13 +37,13 @@ class FastLoginBukkitTest {
 
     @Test
     void testRGB() {
-        val message = "&x00002a00002b&lText";
-        val msg = CommonUtil.translateColorCodes(message);
+        String message = "&x00002a00002b&lText";
+        String msg = CommonUtil.translateColorCodes(message);
         assertEquals(msg, "§x00002a00002b§lText");
 
         @SuppressWarnings("deprecation")
-        val components = TextComponent.fromLegacyText(msg);
-        val expected = "{\"bold\":true,\"color\":\"#00a00b\",\"text\":\"Text\"}";
+        BaseComponent[] components = TextComponent.fromLegacyText(msg);
+        String expected = "{\"bold\":true,\"color\":\"#00a00b\",\"text\":\"Text\"}";
         //noinspection deprecation
         assertEquals(ComponentSerializer.toString(components), expected);
     }

bukkit/src/test/java/com/github/games647/fastlogin/bukkit/listener/protocollib/Base64Adapter.java

@@ -28,7 +28,6 @@ package com.github.games647.fastlogin.bukkit.listener.protocollib;
 import com.google.gson.TypeAdapter;
 import com.google.gson.stream.JsonReader;
 import com.google.gson.stream.JsonWriter;
-import lombok.val;
 
 import java.io.IOException;
 import java.util.Base64;
@@ -37,7 +36,7 @@ public class Base64Adapter extends TypeAdapter<byte[]> {
 
     @Override
     public void write(JsonWriter out, byte[] value) throws IOException {
-        val encoded = Base64.getEncoder().encodeToString(value);
+        String encoded = Base64.getEncoder().encodeToString(value);
         out.value(encoded);
     }
 

bukkit/src/test/java/com/github/games647/fastlogin/bukkit/listener/protocollib/EncryptionUtilTest.java

@@ -27,8 +27,8 @@ package com.github.games647.fastlogin.bukkit.listener.protocollib;
 
 import com.github.games647.fastlogin.bukkit.listener.protocollib.SignatureTestData.SignatureData;
 import com.github.games647.fastlogin.bukkit.listener.protocollib.packet.ClientPublicKey;
+import com.google.common.hash.Hasher;
 import com.google.common.hash.Hashing;
-import lombok.val;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.ValueSource;
@@ -51,6 +51,7 @@ import java.security.SignatureException;
 import java.security.interfaces.RSAPublicKey;
 import java.time.Instant;
 import java.time.temporal.ChronoUnit;
+import java.util.Random;
 import java.util.UUID;
 import java.util.concurrent.ThreadLocalRandom;
 
@@ -60,7 +61,7 @@ class EncryptionUtilTest {
 
     @Test
     void testVerifyToken() {
-        val random = ThreadLocalRandom.current();
+        Random random = ThreadLocalRandom.current();
         byte[] token = EncryptionUtil.generateVerifyToken(random);
 
         assertAll(
@@ -88,10 +89,10 @@ class EncryptionUtilTest {
 
     @Test
     void testExpiredClientKey() throws Exception {
-        val clientKey = ResourceLoader.loadClientKey("client_keys/valid_public_key.json");
+        ClientPublicKey clientKey = ResourceLoader.loadClientKey("client_keys/valid_public_key.json");
 
         // Client expires at the exact second mentioned, so use it for verification
-        val expiredTimestamp = clientKey.expiry();
+        Instant expiredTimestamp = clientKey.expiry();
         assertFalse(EncryptionUtil.verifyClientKey(clientKey, expiredTimestamp, null));
     }
 
@@ -105,7 +106,7 @@ class EncryptionUtilTest {
             "client_keys/invalid_wrong_signature.json"
     })
     void testInvalidClientKey(String clientKeySource) throws Exception {
-        val clientKey = ResourceLoader.loadClientKey(clientKeySource);
+        ClientPublicKey clientKey = ResourceLoader.loadClientKey(clientKeySource);
         Instant expireTimestamp = clientKey.expiry().minus(5, ChronoUnit.HOURS);
 
         assertFalse(EncryptionUtil.verifyClientKey(clientKey, expireTimestamp, null));
@@ -113,34 +114,34 @@ class EncryptionUtilTest {
 
     @Test
     void testValidClientKey() throws Exception {
-        val clientKey = ResourceLoader.loadClientKey("client_keys/valid_public_key.json");
-        val verificationTimestamp = clientKey.expiry().minus(5, ChronoUnit.HOURS);
+        ClientPublicKey clientKey = ResourceLoader.loadClientKey("client_keys/valid_public_key.json");
+        Instant verificationTimestamp = clientKey.expiry().minus(5, ChronoUnit.HOURS);
 
         assertTrue(EncryptionUtil.verifyClientKey(clientKey, verificationTimestamp, null));
     }
 
     @Test
     void testValid191ClientKey() throws Exception {
-        val clientKey = ResourceLoader.loadClientKey("client_keys/valid_public_key_19_1.json");
-        val verificationTimestamp = clientKey.expiry().minus(5, ChronoUnit.HOURS);
+        ClientPublicKey clientKey = ResourceLoader.loadClientKey("client_keys/valid_public_key_19_1.json");
+        Instant verificationTimestamp = clientKey.expiry().minus(5, ChronoUnit.HOURS);
 
-        val ownerPremiumId = UUID.fromString("0aaa2c13-922a-411b-b655-9b8c08404695");
+        UUID ownerPremiumId = UUID.fromString("0aaa2c13-922a-411b-b655-9b8c08404695");
         assertTrue(EncryptionUtil.verifyClientKey(clientKey, verificationTimestamp, ownerPremiumId));
     }
 
     @Test
     void testIncorrect191ClientOwner() throws Exception {
-        val clientKey = ResourceLoader.loadClientKey("client_keys/valid_public_key_19_1.json");
-        val verificationTimestamp = clientKey.expiry().minus(5, ChronoUnit.HOURS);
+        ClientPublicKey clientKey = ResourceLoader.loadClientKey("client_keys/valid_public_key_19_1.json");
+        Instant verificationTimestamp = clientKey.expiry().minus(5, ChronoUnit.HOURS);
 
-        val ownerPremiumId = UUID.fromString("61699b2e-d327-4a01-9f1e-0ea8c3f06bc6");
+        UUID ownerPremiumId = UUID.fromString("61699b2e-d327-4a01-9f1e-0ea8c3f06bc6");
         assertFalse(EncryptionUtil.verifyClientKey(clientKey, verificationTimestamp, ownerPremiumId));
     }
 
     @Test
     void testDecryptSharedSecret() throws Exception {
         KeyPair serverPair = EncryptionUtil.generateKeyPair();
-        val serverPK = serverPair.getPublic();
+        PublicKey serverPK = serverPair.getPublic();
 
         SecretKey secretKey = generateSharedKey();
         byte[] encryptedSecret = encrypt(serverPK, secretKey.getEncoded());
@@ -152,7 +153,7 @@ class EncryptionUtilTest {
     private static byte[] encrypt(PublicKey receiverKey, byte... message)
             throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException,
             IllegalBlockSizeException, BadPaddingException {
-        val encryptCipher = Cipher.getInstance(receiverKey.getAlgorithm());
+        Cipher encryptCipher = Cipher.getInstance(receiverKey.getAlgorithm());
         encryptCipher.init(Cipher.ENCRYPT_MODE, receiverKey);
         return encryptCipher.doFinal(message);
     }
@@ -168,9 +169,9 @@ class EncryptionUtilTest {
 
     @Test
     void testServerIdHash() throws Exception {
-        val serverId = "";
-        val sharedSecret = generateSharedKey();
-        val serverPK = ResourceLoader.loadClientKey("client_keys/valid_public_key.json").key();
+        String serverId = "";
+        SecretKeySpec sharedSecret = generateSharedKey();
+        PublicKey serverPK = ResourceLoader.loadClientKey("client_keys/valid_public_key.json").key();
 
         String sessionHash = getServerHash(serverId, sharedSecret, serverPK);
         assertEquals(EncryptionUtil.getServerIdHashString(serverId, sharedSecret, serverPK), sessionHash);
@@ -185,7 +186,7 @@ class EncryptionUtilTest {
         // sha1.update(server's encoded public key from Encryption Request)
         // hash := sha1.hexdigest() # String of hex characters
         @SuppressWarnings("deprecation")
-        val hasher = Hashing.sha1().newHasher();
+        Hasher hasher = Hashing.sha1().newHasher();
         hasher.putString(serverId, StandardCharsets.US_ASCII);
         hasher.putBytes(sharedSecret.getEncoded());
         hasher.putBytes(serverPK.getEncoded());
@@ -198,9 +199,9 @@ class EncryptionUtilTest {
 
     @Test
     void testServerIdHashWrongSecret() throws Exception {
-        val serverId = "";
-        val sharedSecret = generateSharedKey();
-        val serverPK = ResourceLoader.loadClientKey("client_keys/valid_public_key.json").key();
+        String serverId = "";
+        SecretKeySpec sharedSecret = generateSharedKey();
+        PublicKey serverPK = ResourceLoader.loadClientKey("client_keys/valid_public_key.json").key();
 
         String sessionHash = getServerHash(serverId, sharedSecret, serverPK);
         assertNotEquals(EncryptionUtil.getServerIdHashString("", generateSharedKey(), serverPK), sessionHash);
@@ -208,12 +209,12 @@ class EncryptionUtilTest {
 
     @Test
     void testServerIdHashWrongServerKey() {
-        val serverId = "";
-        val sharedSecret = generateSharedKey();
-        val serverPK = EncryptionUtil.generateKeyPair().getPublic();
+        String serverId = "";
+        SecretKeySpec sharedSecret = generateSharedKey();
+        PublicKey serverPK = EncryptionUtil.generateKeyPair().getPublic();
 
         String sessionHash = getServerHash(serverId, sharedSecret, serverPK);
-        val wrongPK = EncryptionUtil.generateKeyPair().getPublic();
+        PublicKey wrongPK = EncryptionUtil.generateKeyPair().getPublic();
         assertNotEquals(EncryptionUtil.getServerIdHashString("", sharedSecret, wrongPK), sessionHash);
     }
 
@@ -257,8 +258,8 @@ class EncryptionUtilTest {
     @Test
     void testNonce() throws Exception {
         byte[] expected = {1, 2, 3, 4};
-        val serverKey = EncryptionUtil.generateKeyPair();
-        val encryptedNonce = encrypt(serverKey.getPublic(), expected);
+        KeyPair serverKey = EncryptionUtil.generateKeyPair();
+        byte[] encryptedNonce = encrypt(serverKey.getPublic(), expected);
 
         assertTrue(EncryptionUtil.verifyNonce(expected, serverKey.getPrivate(), encryptedNonce));
     }
@@ -266,19 +267,19 @@ class EncryptionUtilTest {
     @Test
     void testNonceIncorrect() throws Exception {
         byte[] expected = {1, 2, 3, 4};
-        val serverKey = EncryptionUtil.generateKeyPair();
+        KeyPair serverKey = EncryptionUtil.generateKeyPair();
 
         // flipped first character
-        val encryptedNonce = encrypt(serverKey.getPublic(), new byte[]{0, 2, 3, 4});
+        byte[] encryptedNonce = encrypt(serverKey.getPublic(), new byte[]{0, 2, 3, 4});
         assertFalse(EncryptionUtil.verifyNonce(expected, serverKey.getPrivate(), encryptedNonce));
     }
 
     @Test
     void testNonceFailedDecryption() throws Exception {
         byte[] expected = {1, 2, 3, 4};
-        val serverKey = EncryptionUtil.generateKeyPair();
+        KeyPair serverKey = EncryptionUtil.generateKeyPair();
         // generate a new keypair that is different
-        val encryptedNonce = encrypt(EncryptionUtil.generateKeyPair().getPublic(), expected);
+        byte[] encryptedNonce = encrypt(EncryptionUtil.generateKeyPair().getPublic(), expected);
 
         assertThrows(GeneralSecurityException.class,
                 () -> EncryptionUtil.verifyNonce(expected, serverKey.getPrivate(), encryptedNonce)
@@ -288,7 +289,7 @@ class EncryptionUtilTest {
     @Test
     void testNonceIncorrectEmpty() {
         byte[] expected = {1, 2, 3, 4};
-        val serverKey = EncryptionUtil.generateKeyPair();
+        KeyPair serverKey = EncryptionUtil.generateKeyPair();
         byte[] encryptedNonce = {};
 
         assertThrows(GeneralSecurityException.class,

bukkit/src/test/java/com/github/games647/fastlogin/bukkit/listener/protocollib/SignatureTestData.java

@@ -28,16 +28,16 @@ package com.github.games647.fastlogin.bukkit.listener.protocollib;
 import com.google.common.io.Resources;
 import com.google.gson.Gson;
 import com.google.gson.annotations.JsonAdapter;
-import lombok.val;
 
 import java.io.IOException;
+import java.net.URL;
 import java.nio.charset.StandardCharsets;
 
 public class SignatureTestData {
 
     public static SignatureTestData fromResource(String resourceName) throws IOException {
-        val keyUrl = Resources.getResource(resourceName);
-        val encodedSignature = Resources.toString(keyUrl, StandardCharsets.US_ASCII);
+        URL keyUrl = Resources.getResource(resourceName);
+        String encodedSignature = Resources.toString(keyUrl, StandardCharsets.US_ASCII);
 
         return new Gson().fromJson(encodedSignature, SignatureTestData.class);
     }

bukkit/src/test/java/com/github/games647/fastlogin/bukkit/task/DelayedAuthHookTest.java

@@ -26,7 +26,6 @@
 package com.github.games647.fastlogin.bukkit.task;
 
 import com.github.games647.fastlogin.core.hooks.AuthPlugin;
-import lombok.val;
 import org.bukkit.entity.Player;
 import org.junit.jupiter.api.Test;
 
@@ -36,7 +35,7 @@ class DelayedAuthHookTest {
 
     @Test
     void createNewReflectiveInstance() throws ReflectiveOperationException {
-        val authHook = new DelayedAuthHook(null);
+        DelayedAuthHook authHook = new DelayedAuthHook(null);
         assertNotNull(authHook.newInstance(DummyHook.class));
     }
 

bungee/src/main/java/com/github/games647/fastlogin/bungee/task/AsyncToggleMessage.java

@@ -76,7 +76,12 @@ public class AsyncToggleMessage implements Runnable {
             ? PremiumToggleReason.COMMAND_OTHER : PremiumToggleReason.COMMAND_SELF;
         core.getPlugin().getProxy().getPluginManager().callEvent(
                 new BungeeFastLoginPremiumToggleEvent(playerProfile, reason));
-        sendMessage("remove-premium");
+
+        if (isPlayerSender && core.getConfig().getBoolean("kick-toggle", true)) {
+            sender.disconnect(TextComponent.fromLegacyText(core.getMessage("remove-premium")));
+        } else {
+            sendMessage("remove-premium");
+        }
     }
 
     private void activatePremium() {

core/pom.xml

@@ -147,7 +147,7 @@
         <dependency>
             <groupId>net.md-5</groupId>
             <artifactId>bungeecord-config</artifactId>
-            <version>1.20-R0.2-SNAPSHOT</version>
+            <version>1.20-R0.2</version>
         </dependency>
 
         <!-- This is optional in BungeeCord-config, so we include it here manually -->

core/src/main/java/com/github/games647/fastlogin/core/message/LoginActionMessage.java

@@ -63,7 +63,7 @@ public class LoginActionMessage implements ChannelMessage {
 
     @Override
     public void readFrom(ByteArrayDataInput input) {
-        this.type = Type.values()[input.readInt()];
+        this.type = Type.values()[input.readByte()];
 
         this.playerName = input.readUTF();
 
@@ -75,7 +75,7 @@ public class LoginActionMessage implements ChannelMessage {
 
     @Override
     public void writeTo(ByteArrayDataOutput output) {
-        output.writeInt(type.ordinal());
+        output.writeByte(type.ordinal());
 
         //Data is sent through a random player. We have to tell the Bukkit version of this plugin the target
         output.writeUTF(playerName);

core/src/main/java/com/github/games647/fastlogin/core/scheduler/AsyncScheduler.java

@@ -42,7 +42,8 @@ public class AsyncScheduler extends AbstractAsyncScheduler {
 
     public AsyncScheduler(Logger logger, Executor processingPool) {
         super(logger, processingPool);
-        logger.info("Using legacy scheduler");
+        logger.info("Using legacy platform scheduler for using an older Java version. "
+            + "Upgrade Java to 21+ for improved performance");
     }
 
     @Override

core/src/main/resources/config.yml

@@ -150,11 +150,14 @@ nameChangeCheck: false
 forwardSkin: true
 
 # Displays a warning message that this message SHOULD only be invoked by
-# users who actually are the owner of this account. So not by cracked players
+# users who actually are the owner of this account (and not cracked players)
 #
 # If they still want to invoke the command, they have to invoke /premium again
 premium-warning: true
 
+# Kick players after they confirmed the command from above.
+kick-toggle: true
+
 # ======[[ Spigot+ProtocolLib users only ]]======
 # When set to true, enables the use of alternative session resolver which does not send the server IP
 # to mojang session servers. This setting might be useful when you are trying to run the server via a

pom.xml

@@ -218,14 +218,6 @@
     </build>
 
     <dependencies>
-        <!-- Use lombok to use some newer Java syntax features in Java 8 -->
-        <dependency>
-            <groupId>org.projectlombok</groupId>
-            <artifactId>lombok</artifactId>
-            <version>${lombook.version}</version>
-            <scope>provided</scope>
-        </dependency>
-
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter</artifactId>
@@ -237,7 +229,7 @@
         <dependency>
             <groupId>org.mockito</groupId>
             <artifactId>mockito-core</artifactId>
-            <version>5.12.0</version>
+            <version>5.17.0</version>
             <scope>test</scope>
         </dependency>
     </dependencies>

velocity/src/main/java/com/github/games647/fastlogin/velocity/FastLoginVelocity.java

@@ -46,6 +46,7 @@ import com.velocitypowered.api.event.proxy.ProxyInitializeEvent;
 import com.velocitypowered.api.event.proxy.ProxyShutdownEvent;
 import com.velocitypowered.api.plugin.Plugin;
 import com.velocitypowered.api.plugin.annotation.DataDirectory;
+import com.velocitypowered.api.proxy.InboundConnection;
 import com.velocitypowered.api.proxy.Player;
 import com.velocitypowered.api.proxy.ProxyServer;
 import com.velocitypowered.api.proxy.messages.ChannelMessageSink;
@@ -57,7 +58,6 @@ import org.geysermc.geyser.GeyserImpl;
 import org.slf4j.Logger;
 
 import java.io.IOException;
-import java.net.InetSocketAddress;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -75,7 +75,7 @@ public class FastLoginVelocity implements PlatformPlugin<CommandSource> {
     private final ProxyServer server;
     private final Path dataDirectory;
     private final Logger logger;
-    private final ConcurrentMap<InetSocketAddress, VelocityLoginSession> session = new MapMaker().weakKeys().makeMap();
+    private final ConcurrentMap<InboundConnection, VelocityLoginSession> session = new MapMaker().weakKeys().makeMap();
     private static final String PROXY_ID_FILE = "proxyId.txt";
 
     private FastLoginCore<Player, CommandSource, FastLoginVelocity> core;
@@ -175,7 +175,7 @@ public class FastLoginVelocity implements PlatformPlugin<CommandSource> {
         return core;
     }
 
-    public ConcurrentMap<InetSocketAddress, VelocityLoginSession> getSession() {
+    public ConcurrentMap<InboundConnection, VelocityLoginSession> getSession() {
         return session;
     }
 

velocity/src/main/java/com/github/games647/fastlogin/velocity/VelocityLoginSource.java

@@ -66,4 +66,8 @@ public class VelocityLoginSource implements LoginSource {
     public InetSocketAddress getAddress() {
         return connection.getRemoteAddress();
     }
+
+    public InboundConnection getConnection() {
+        return connection;
+    }
 }

velocity/src/main/java/com/github/games647/fastlogin/velocity/listener/ConnectListener.java

@@ -119,9 +119,9 @@ public class ConnectListener {
     @Subscribe
     public void onGameProfileRequest(GameProfileRequestEvent event) {
         if (event.isOnlineMode()) {
-            LoginSession session = plugin.getSession().get(event.getConnection().getRemoteAddress());
+            LoginSession session = plugin.getSession().get(event.getConnection());
             if (session == null) {
-                plugin.getLog().warn("No active login session found for player {}", event.getUsername());
+                plugin.getLog().error("No active login session found for onlinemode player {}", event.getUsername());
                 return;
             }
 
@@ -173,7 +173,7 @@ public class ConnectListener {
             }
         }
 
-        VelocityLoginSession session = plugin.getSession().get(player.getRemoteAddress());
+        VelocityLoginSession session = plugin.getSession().get(player);
         if (session == null) {
             plugin.getLog().info("No active login session found on server connect for {}", player);
             return;
@@ -192,6 +192,8 @@ public class ConnectListener {
     public void onDisconnect(DisconnectEvent disconnectEvent) {
         Player player = disconnectEvent.getPlayer();
         plugin.getCore().getPendingConfirms().remove(player.getUniqueId());
+
+        plugin.getSession().remove(player);
     }
 
     /**

velocity/src/main/java/com/github/games647/fastlogin/velocity/listener/PluginMessageListener.java

@@ -83,12 +83,12 @@ public class PluginMessageListener {
         plugin.getScheduler().runAsync(() -> readMessage(forPlayer, channel, data));
     }
 
-    private void readMessage(Player forPlayer, String channel, byte[] data) {
+    private void readMessage(Player sender, String channel, byte[] data) {
         FastLoginCore<Player, CommandSource, FastLoginVelocity> core = plugin.getCore();
 
         ByteArrayDataInput dataInput = ByteStreams.newDataInput(data);
         if (successChannel.equals(channel)) {
-            onSuccessMessage(forPlayer);
+            onSuccessMessage(sender);
         } else if (changeChannel.equals(channel)) {
             ChangePremiumMessage changeMessage = new ChangePremiumMessage();
             changeMessage.readFrom(dataInput);
@@ -97,19 +97,19 @@ public class PluginMessageListener {
             boolean isSourceInvoker = changeMessage.isSourceInvoker();
             if (changeMessage.shouldEnable()) {
                 Boolean premiumWarning = plugin.getCore().getConfig().get("premium-warning", true);
-                if (playerName.equals(forPlayer.getUsername()) && premiumWarning
-                    && !core.getPendingConfirms().contains(forPlayer.getUniqueId())) {
+                if (playerName.equals(sender.getUsername()) && premiumWarning
+                    && !core.getPendingConfirms().contains(sender.getUniqueId())) {
                     String message = core.getMessage("premium-warning");
-                    forPlayer.sendMessage(LegacyComponentSerializer.legacyAmpersand().deserialize(message));
-                    core.getPendingConfirms().add(forPlayer.getUniqueId());
+                    sender.sendMessage(LegacyComponentSerializer.legacyAmpersand().deserialize(message));
+                    core.getPendingConfirms().add(sender.getUniqueId());
                     return;
                 }
 
-                core.getPendingConfirms().remove(forPlayer.getUniqueId());
-                Runnable task = new AsyncToggleMessage(core, forPlayer, playerName, true, isSourceInvoker);
+                core.getPendingConfirms().remove(sender.getUniqueId());
+                Runnable task = new AsyncToggleMessage(core, sender, playerName, true, isSourceInvoker);
                 plugin.getScheduler().runAsync(task);
             } else {
-                Runnable task = new AsyncToggleMessage(core, forPlayer, playerName, false, isSourceInvoker);
+                Runnable task = new AsyncToggleMessage(core, sender, playerName, false, isSourceInvoker);
                 plugin.getScheduler().runAsync(task);
             }
         }
@@ -127,7 +127,7 @@ public class PluginMessageListener {
         if (shouldPersist) {
             //bukkit module successfully received and force logged in the user
             //update only on success to prevent corrupt data
-            VelocityLoginSession loginSession = plugin.getSession().get(forPlayer.getRemoteAddress());
+            VelocityLoginSession loginSession = plugin.getSession().get(forPlayer);
             StoredProfile playerProfile = loginSession.getProfile();
             loginSession.setRegistered(true);
             if (!loginSession.isAlreadySaved()) {

velocity/src/main/java/com/github/games647/fastlogin/velocity/task/AsyncPremiumCheck.java

@@ -58,7 +58,7 @@ public class AsyncPremiumCheck extends JoinManagement<Player, CommandSource, Vel
 
     @Override
     public void run() {
-        plugin.getSession().remove(connection.getRemoteAddress());
+        plugin.getSession().remove(connection);
         super.onLogin(username, new VelocityLoginSource(connection, preLoginEvent));
     }
 
@@ -82,7 +82,7 @@ public class AsyncPremiumCheck extends JoinManagement<Player, CommandSource, Vel
                                     String username, boolean registered) {
         source.enableOnlinemode();
         VelocityLoginSession session = new VelocityLoginSession(username, registered, profile);
-        plugin.getSession().put(source.getAddress(), session);
+        plugin.getSession().put(source.getConnection(), session);
 
         String ip = source.getAddress().getAddress().getHostAddress();
         plugin.getCore().addLoginAttempt(ip, username);
@@ -91,6 +91,6 @@ public class AsyncPremiumCheck extends JoinManagement<Player, CommandSource, Vel
     @Override
     public void startCrackedSession(VelocityLoginSource source, StoredProfile profile, String username) {
         VelocityLoginSession session = new VelocityLoginSession(username, false, profile);
-        plugin.getSession().put(source.getAddress(), session);
+        plugin.getSession().put(source.getConnection(), session);
     }
 }

velocity/src/main/java/com/github/games647/fastlogin/velocity/task/AsyncToggleMessage.java

@@ -33,29 +33,26 @@ import com.github.games647.fastlogin.velocity.event.VelocityFastLoginPremiumTogg
 import com.velocitypowered.api.command.CommandSource;
 import com.velocitypowered.api.proxy.ConsoleCommandSource;
 import com.velocitypowered.api.proxy.Player;
+import net.kyori.adventure.text.TextComponent;
 import net.kyori.adventure.text.serializer.legacy.LegacyComponentSerializer;
 
 public class AsyncToggleMessage implements Runnable {
 
     private final FastLoginCore<Player, CommandSource, FastLoginVelocity> core;
-    private final CommandSource sender;
+    private final Player sender;
     private final String senderName;
     private final String targetPlayer;
     private final boolean toPremium;
     private final boolean isPlayerSender;
 
     public AsyncToggleMessage(FastLoginCore<Player, CommandSource, FastLoginVelocity> core,
-                              CommandSource sender, String playerName, boolean toPremium, boolean playerSender) {
+                              Player sender, String playerName, boolean toPremium, boolean playerSender) {
         this.core = core;
         this.sender = sender;
         this.targetPlayer = playerName;
         this.toPremium = toPremium;
         this.isPlayerSender = playerSender;
-        if (sender instanceof Player playSender) {
-            senderName = playSender.getUsername();
-        } else {
-            senderName = "";
-        }
+        this.senderName = sender.getUsername();
     }
 
     @Override
@@ -82,7 +79,14 @@ public class AsyncToggleMessage implements Runnable {
             ? PremiumToggleReason.COMMAND_OTHER : PremiumToggleReason.COMMAND_SELF;
         core.getPlugin().getProxy().getEventManager().fire(
             new VelocityFastLoginPremiumToggleEvent(playerProfile, reason));
-        sendMessage("remove-premium");
+
+        if (isPlayerSender && core.getConfig().getBoolean("kick-toggle", true)) {
+            TextComponent msg = LegacyComponentSerializer.legacyAmpersand()
+                .deserialize(core.getMessage("remove-premium"));
+            sender.disconnect(msg);
+        } else {
+            sendMessage("remove-premium");
+        }
     }
 
     private void activatePremium() {

velocity/src/main/java/com/github/games647/fastlogin/velocity/task/FloodgateAuthTask.java

@@ -52,7 +52,7 @@ public class FloodgateAuthTask
     @Override
     protected void startLogin() {
         VelocityLoginSession session = new VelocityLoginSession(player.getUsername(), isRegistered, profile);
-        core.getPlugin().getSession().put(player.getRemoteAddress(), session);
+        core.getPlugin().getSession().put(player, session);
 
         // enable auto login based on the value of 'autoLoginFloodgate' in config.yml
         boolean forcedOnlineMode = autoLoginFloodgate.equals("true")