Netty WIP

Implementing ByteBuf backed In/OutPacket first in a separate branch

src/main/java/client/MapleClient.java

@@ -24,6 +24,10 @@ package client;
 import client.inventory.MapleInventoryType;
 import config.YamlConfig;
 import constants.game.GameConstants;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelInboundHandlerAdapter;
+import net.netty.ClientCyphers;
+import net.netty.InvalidPacketHeaderException;
 import net.server.Server;
 import net.server.audit.locks.MonitoredLockType;
 import net.server.audit.locks.factory.MonitoredReentrantLockFactory;
@@ -61,7 +65,7 @@ import java.util.*;
 import java.util.concurrent.Semaphore;
 import java.util.concurrent.locks.Lock;
 
-public class MapleClient {
+public class MapleClient extends ChannelInboundHandlerAdapter {
 
     public static final int LOGIN_NOTLOGGEDIN = 0;
     public static final int LOGIN_SERVER_TRANSITION = 1;
@@ -118,12 +122,32 @@ public class MapleClient {
         return lastPacket;
     }
 
+    public MapleClient(ClientCyphers cyphers) {
+        this.send = cyphers.getSendCypher();
+        this.receive = cyphers.getReceiveCypher();
+        this.session = null; // TODO remove once the other constructor is removed
+    }
+
     public MapleClient(MapleAESOFB send, MapleAESOFB receive, IoSession session) {
         this.send = send;
         this.receive = receive;
         this.session = session;
     }
 
+    @Override
+    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
+        super.channelRead(ctx, msg);
+    }
+
+    @Override
+    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
+        if (cause instanceof InvalidPacketHeaderException) {
+            // TODO close session through MapleSessionCoordinator
+        }
+
+        super.exceptionCaught(ctx, cause);
+    }
+
     public MapleAESOFB getReceiveCrypto() {
         return receive;
     }

src/main/java/constants/net/ServerConstants.java

@@ -3,7 +3,7 @@ package constants.net;
 public class ServerConstants {
     
     //Server Version
-    public static short VERSION = 83;
+    public static final short VERSION = 83;
 
     //Debug Variables
     public static int[] DEBUG_VALUES = new int[10];             // Field designed for packet testing purposes

src/main/java/net/MapleServerHandler.java

@@ -24,6 +24,7 @@ package net;
 import client.MapleClient;
 import config.YamlConfig;
 import constants.net.ServerConstants;
+import net.netty.InitializationVector;
 import net.server.Server;
 import net.server.audit.LockCollector;
 import net.server.audit.locks.MonitoredLockType;
@@ -130,10 +131,8 @@ public class MapleServerHandler extends IoHandlerAdapter {
             FilePrinter.print(FilePrinter.SESSION, "IoSession with " + session.getRemoteAddress() + " opened on " + sdf.format(Calendar.getInstance().getTime()), false);
         }
 
-        byte[] ivRecv = {70, 114, 122, 82};
-        byte[] ivSend = {82, 48, 120, 115};
-        ivRecv[3] = (byte) (Math.random() * 255);
-        ivSend[3] = (byte) (Math.random() * 255);
+        final InitializationVector ivSend = InitializationVector.generateSend();
+        final InitializationVector ivRecv = InitializationVector.generateReceive();
         MapleAESOFB sendCypher = new MapleAESOFB(ivSend, (short) (0xFFFF - ServerConstants.VERSION));
         MapleAESOFB recvCypher = new MapleAESOFB(ivRecv, ServerConstants.VERSION);
         MapleClient client = new MapleClient(sendCypher, recvCypher, session);

src/main/java/net/netty/ClientCyphers.java

@@ -0,0 +1,28 @@
+package net.netty;
+
+import constants.net.ServerConstants;
+import tools.MapleAESOFB;
+
+public class ClientCyphers {
+    private final MapleAESOFB send;
+    private final MapleAESOFB receive;
+
+    private ClientCyphers(MapleAESOFB send, MapleAESOFB receive) {
+        this.send = send;
+        this.receive = receive;
+    }
+
+    public static ClientCyphers generateNew() {
+        MapleAESOFB send = new MapleAESOFB(InitializationVector.generateSend(), ServerConstants.VERSION);
+        MapleAESOFB receive = new MapleAESOFB(InitializationVector.generateReceive(), ServerConstants.VERSION);
+        return new ClientCyphers(send, receive);
+    }
+
+    public MapleAESOFB getSendCypher() {
+        return send;
+    }
+
+    public MapleAESOFB getReceiveCypher() {
+        return receive;
+    }
+}

src/main/java/net/netty/ClientInitializer.java

@@ -0,0 +1,20 @@
+package net.netty;
+
+import client.MapleClient;
+import io.netty.channel.ChannelInitializer;
+import io.netty.channel.socket.SocketChannel;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class ClientInitializer extends ChannelInitializer<SocketChannel> {
+    private static final Logger log = LoggerFactory.getLogger(ClientInitializer.class);
+
+    @Override
+    public void initChannel(SocketChannel socketChannel) {
+        final String clientIp = socketChannel.remoteAddress().getHostName();
+        log.debug("Client initiated new connection from: {}", clientIp);
+
+        MapleClient client = new MapleClient(ClientCyphers.generateNew());
+        socketChannel.pipeline().addLast("MapleClient", client);
+    }
+}

src/main/java/net/netty/InPacket.java

@@ -0,0 +1,4 @@
+package net.netty;
+
+public class InPacket {
+}

src/main/java/net/netty/InitializationVector.java

@@ -0,0 +1,27 @@
+package net.netty;
+
+public class InitializationVector {
+    private final byte[] bytes;
+
+    private InitializationVector(byte[] bytes) {
+        this.bytes = bytes;
+    }
+
+    public byte[] getBytes() {
+        return bytes;
+    }
+
+    public static InitializationVector generateSend() {
+        byte[] ivSend = {82, 48, 120, getRandomByte()};
+        return new InitializationVector(ivSend);
+    }
+
+    public static InitializationVector generateReceive() {
+        byte[] ivRecv = {70, 114, 122, getRandomByte()};
+        return new InitializationVector(ivRecv);
+    }
+
+    private static byte getRandomByte() {
+        return (byte) (Math.random() * 255);
+    }
+}

src/main/java/net/netty/InvalidPacketHeaderException.java

@@ -0,0 +1,14 @@
+package net.netty;
+
+public class InvalidPacketHeaderException extends RuntimeException {
+    private final int header;
+
+    public InvalidPacketHeaderException(String message, int header) {
+        super(message);
+        this.header = header;
+    }
+
+    public int getHeader() {
+        return header;
+    }
+}

src/main/java/net/netty/OutPacket.java

@@ -0,0 +1,5 @@
+package net.netty;
+
+public interface OutPacket {
+    byte[] getBytes();
+}

src/main/java/net/netty/PacketDecoder.java

@@ -0,0 +1,48 @@
+package net.netty;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.handler.codec.ReplayingDecoder;
+import net.mina.MapleCustomEncryption;
+import tools.MapleAESOFB;
+
+import java.util.List;
+
+public class PacketDecoder extends ReplayingDecoder<Void> {
+    private final MapleAESOFB receiveCypher;
+
+    public PacketDecoder(MapleAESOFB receiveCypher) {
+        this.receiveCypher = receiveCypher;
+    }
+
+    @Override
+    protected void decode(ChannelHandlerContext context, ByteBuf in, List<Object> out) {
+        final int header = in.readInt();
+
+        if (!receiveCypher.checkPacket(header)) {
+            throw new InvalidPacketHeaderException("Attempted to decode a packet with an invalid header", header);
+        }
+
+        int packetLength = decodePacketLength(header);
+        byte[] packet = new byte[packetLength];
+        in.readBytes(packet);
+        receiveCypher.crypt(packet);
+        MapleCustomEncryption.decryptData(packet);
+        out.add(packet);
+        // TODO conditionally log the packet
+    }
+
+    /**
+     * @param header Packet header - the first 4 bytes of the packet
+     * @return Packet size in bytes
+     */
+    private static int decodePacketLength(byte[] header) {
+        return (((header[1] ^ header[3]) & 0xFF) << 8) | ((header[0] ^ header[2]) & 0xFF);
+    }
+
+    private static int decodePacketLength(int header) {
+        int length = ((header >>> 16) ^ (header & 0xFFFF));
+        length = ((length << 8) & 0xFF00) | ((length >>> 8) & 0xFF);
+        return length;
+    }
+}

src/main/java/net/netty/PacketEncoder.java

@@ -0,0 +1,28 @@
+package net.netty;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.handler.codec.MessageToByteEncoder;
+import net.mina.MapleCustomEncryption;
+import tools.MapleAESOFB;
+
+public class PacketEncoder extends MessageToByteEncoder<OutPacket> {
+    private final MapleAESOFB sendCypher;
+
+    public PacketEncoder(MapleAESOFB sendCypher) {
+        this.sendCypher = sendCypher;
+    }
+
+    @Override
+    protected void encode(ChannelHandlerContext ctx, OutPacket in, ByteBuf out) {
+        byte[] packet = in.getBytes();
+        out.writeBytes(getEncodedHeader(packet.length));
+        MapleCustomEncryption.encryptData(packet);
+        sendCypher.crypt(packet);
+        out.writeBytes(packet);
+    }
+
+    private byte[] getEncodedHeader(int length) {
+        return sendCypher.getPacketHeader(length);
+    }
+}

src/main/java/tools/MapleAESOFB.java

@@ -21,6 +21,10 @@
 */
 package tools;
 
+import net.netty.InitializationVector;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import javax.crypto.BadPaddingException;
 import javax.crypto.Cipher;
 import javax.crypto.IllegalBlockSizeException;
@@ -30,52 +34,73 @@ import java.security.InvalidKeyException;
 import java.security.NoSuchAlgorithmException;
 
 public class MapleAESOFB {
-    private byte[] iv;
-    private Cipher cipher;
-    private short mapleVersion;
+    private static final Logger log = LoggerFactory.getLogger(MapleAESOFB.class);
     private final static SecretKeySpec skey = new SecretKeySpec(
-        new byte[]{0x13, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00, (byte) 0xB4, 0x00, 0x00, 0x00, 0x1B, 0x00, 0x00, 0x00, 0x0F, 0x00, 0x00, 0x00, 0x33, 0x00, 0x00, 0x00, 0x52, 0x00, 0x00, 0x00}, "AES");
+        new byte[]{
+                0x13, 0x00, 0x00, 0x00,
+                0x08, 0x00, 0x00, 0x00,
+                0x06, 0x00, 0x00, 0x00,
+                (byte) 0xB4, 0x00, 0x00, 0x00,
+                0x1B, 0x00, 0x00, 0x00,
+                0x0F, 0x00, 0x00, 0x00,
+                0x33, 0x00, 0x00, 0x00,
+                0x52, 0x00, 0x00, 0x00}, "AES");
 
-    private static final byte[] funnyBytes = new byte[]{(byte) 0xEC, (byte) 0x3F, (byte) 0x77, (byte) 0xA4, (byte) 0x45, (byte) 0xD0, (byte) 0x71, (byte) 0xBF, (byte) 0xB7, (byte) 0x98, (byte) 0x20, (byte) 0xFC,
-        (byte) 0x4B, (byte) 0xE9, (byte) 0xB3, (byte) 0xE1, (byte) 0x5C, (byte) 0x22, (byte) 0xF7, (byte) 0x0C, (byte) 0x44, (byte) 0x1B, (byte) 0x81, (byte) 0xBD, (byte) 0x63, (byte) 0x8D, (byte) 0xD4, (byte) 0xC3,
-        (byte) 0xF2, (byte) 0x10, (byte) 0x19, (byte) 0xE0, (byte) 0xFB, (byte) 0xA1, (byte) 0x6E, (byte) 0x66, (byte) 0xEA, (byte) 0xAE, (byte) 0xD6, (byte) 0xCE, (byte) 0x06, (byte) 0x18, (byte) 0x4E, (byte) 0xEB,
-        (byte) 0x78, (byte) 0x95, (byte) 0xDB, (byte) 0xBA, (byte) 0xB6, (byte) 0x42, (byte) 0x7A, (byte) 0x2A, (byte) 0x83, (byte) 0x0B, (byte) 0x54, (byte) 0x67, (byte) 0x6D, (byte) 0xE8, (byte) 0x65, (byte) 0xE7,
-        (byte) 0x2F, (byte) 0x07, (byte) 0xF3, (byte) 0xAA, (byte) 0x27, (byte) 0x7B, (byte) 0x85, (byte) 0xB0, (byte) 0x26, (byte) 0xFD, (byte) 0x8B, (byte) 0xA9, (byte) 0xFA, (byte) 0xBE, (byte) 0xA8, (byte) 0xD7,
-        (byte) 0xCB, (byte) 0xCC, (byte) 0x92, (byte) 0xDA, (byte) 0xF9, (byte) 0x93, (byte) 0x60, (byte) 0x2D, (byte) 0xDD, (byte) 0xD2, (byte) 0xA2, (byte) 0x9B, (byte) 0x39, (byte) 0x5F, (byte) 0x82, (byte) 0x21,
-        (byte) 0x4C, (byte) 0x69, (byte) 0xF8, (byte) 0x31, (byte) 0x87, (byte) 0xEE, (byte) 0x8E, (byte) 0xAD, (byte) 0x8C, (byte) 0x6A, (byte) 0xBC, (byte) 0xB5, (byte) 0x6B, (byte) 0x59, (byte) 0x13, (byte) 0xF1,
-        (byte) 0x04, (byte) 0x00, (byte) 0xF6, (byte) 0x5A, (byte) 0x35, (byte) 0x79, (byte) 0x48, (byte) 0x8F, (byte) 0x15, (byte) 0xCD, (byte) 0x97, (byte) 0x57, (byte) 0x12, (byte) 0x3E, (byte) 0x37, (byte) 0xFF,
-        (byte) 0x9D, (byte) 0x4F, (byte) 0x51, (byte) 0xF5, (byte) 0xA3, (byte) 0x70, (byte) 0xBB, (byte) 0x14, (byte) 0x75, (byte) 0xC2, (byte) 0xB8, (byte) 0x72, (byte) 0xC0, (byte) 0xED, (byte) 0x7D, (byte) 0x68,
-        (byte) 0xC9, (byte) 0x2E, (byte) 0x0D, (byte) 0x62, (byte) 0x46, (byte) 0x17, (byte) 0x11, (byte) 0x4D, (byte) 0x6C, (byte) 0xC4, (byte) 0x7E, (byte) 0x53, (byte) 0xC1, (byte) 0x25, (byte) 0xC7, (byte) 0x9A,
-        (byte) 0x1C, (byte) 0x88, (byte) 0x58, (byte) 0x2C, (byte) 0x89, (byte) 0xDC, (byte) 0x02, (byte) 0x64, (byte) 0x40, (byte) 0x01, (byte) 0x5D, (byte) 0x38, (byte) 0xA5, (byte) 0xE2, (byte) 0xAF, (byte) 0x55,
-        (byte) 0xD5, (byte) 0xEF, (byte) 0x1A, (byte) 0x7C, (byte) 0xA7, (byte) 0x5B, (byte) 0xA6, (byte) 0x6F, (byte) 0x86, (byte) 0x9F, (byte) 0x73, (byte) 0xE6, (byte) 0x0A, (byte) 0xDE, (byte) 0x2B, (byte) 0x99,
-        (byte) 0x4A, (byte) 0x47, (byte) 0x9C, (byte) 0xDF, (byte) 0x09, (byte) 0x76, (byte) 0x9E, (byte) 0x30, (byte) 0x0E, (byte) 0xE4, (byte) 0xB2, (byte) 0x94, (byte) 0xA0, (byte) 0x3B, (byte) 0x34, (byte) 0x1D,
-        (byte) 0x28, (byte) 0x0F, (byte) 0x36, (byte) 0xE3, (byte) 0x23, (byte) 0xB4, (byte) 0x03, (byte) 0xD8, (byte) 0x90, (byte) 0xC8, (byte) 0x3C, (byte) 0xFE, (byte) 0x5E, (byte) 0x32, (byte) 0x24, (byte) 0x50,
-        (byte) 0x1F, (byte) 0x3A, (byte) 0x43, (byte) 0x8A, (byte) 0x96, (byte) 0x41, (byte) 0x74, (byte) 0xAC, (byte) 0x52, (byte) 0x33, (byte) 0xF0, (byte) 0xD9, (byte) 0x29, (byte) 0x80, (byte) 0xB1, (byte) 0x16,
-        (byte) 0xD3, (byte) 0xAB, (byte) 0x91, (byte) 0xB9, (byte) 0x84, (byte) 0x7F, (byte) 0x61, (byte) 0x1E, (byte) 0xCF, (byte) 0xC5, (byte) 0xD1, (byte) 0x56, (byte) 0x3D, (byte) 0xCA, (byte) 0xF4, (byte) 0x05,
-        (byte) 0xC6, (byte) 0xE5, (byte) 0x08, (byte) 0x49};
+    private static final byte[] funnyBytes = new byte[]{
+            (byte) 0xEC, (byte) 0x3F, (byte) 0x77, (byte) 0xA4, (byte) 0x45, (byte) 0xD0, (byte) 0x71, (byte) 0xBF,
+            (byte) 0xB7, (byte) 0x98, (byte) 0x20, (byte) 0xFC, (byte) 0x4B, (byte) 0xE9, (byte) 0xB3, (byte) 0xE1,
+            (byte) 0x5C, (byte) 0x22, (byte) 0xF7, (byte) 0x0C, (byte) 0x44, (byte) 0x1B, (byte) 0x81, (byte) 0xBD,
+            (byte) 0x63, (byte) 0x8D, (byte) 0xD4, (byte) 0xC3, (byte) 0xF2, (byte) 0x10, (byte) 0x19, (byte) 0xE0,
+            (byte) 0xFB, (byte) 0xA1, (byte) 0x6E, (byte) 0x66, (byte) 0xEA, (byte) 0xAE, (byte) 0xD6, (byte) 0xCE,
+            (byte) 0x06, (byte) 0x18, (byte) 0x4E, (byte) 0xEB, (byte) 0x78, (byte) 0x95, (byte) 0xDB, (byte) 0xBA,
+            (byte) 0xB6, (byte) 0x42, (byte) 0x7A, (byte) 0x2A, (byte) 0x83, (byte) 0x0B, (byte) 0x54, (byte) 0x67,
+            (byte) 0x6D, (byte) 0xE8, (byte) 0x65, (byte) 0xE7, (byte) 0x2F, (byte) 0x07, (byte) 0xF3, (byte) 0xAA,
+            (byte) 0x27, (byte) 0x7B, (byte) 0x85, (byte) 0xB0, (byte) 0x26, (byte) 0xFD, (byte) 0x8B, (byte) 0xA9,
+            (byte) 0xFA, (byte) 0xBE, (byte) 0xA8, (byte) 0xD7, (byte) 0xCB, (byte) 0xCC, (byte) 0x92, (byte) 0xDA,
+            (byte) 0xF9, (byte) 0x93, (byte) 0x60, (byte) 0x2D, (byte) 0xDD, (byte) 0xD2, (byte) 0xA2, (byte) 0x9B,
+            (byte) 0x39, (byte) 0x5F, (byte) 0x82, (byte) 0x21, (byte) 0x4C, (byte) 0x69, (byte) 0xF8, (byte) 0x31,
+            (byte) 0x87, (byte) 0xEE, (byte) 0x8E, (byte) 0xAD, (byte) 0x8C, (byte) 0x6A, (byte) 0xBC, (byte) 0xB5,
+            (byte) 0x6B, (byte) 0x59, (byte) 0x13, (byte) 0xF1, (byte) 0x04, (byte) 0x00, (byte) 0xF6, (byte) 0x5A,
+            (byte) 0x35, (byte) 0x79, (byte) 0x48, (byte) 0x8F, (byte) 0x15, (byte) 0xCD, (byte) 0x97, (byte) 0x57,
+            (byte) 0x12, (byte) 0x3E, (byte) 0x37, (byte) 0xFF, (byte) 0x9D, (byte) 0x4F, (byte) 0x51, (byte) 0xF5,
+            (byte) 0xA3, (byte) 0x70, (byte) 0xBB, (byte) 0x14, (byte) 0x75, (byte) 0xC2, (byte) 0xB8, (byte) 0x72,
+            (byte) 0xC0, (byte) 0xED, (byte) 0x7D, (byte) 0x68, (byte) 0xC9, (byte) 0x2E, (byte) 0x0D, (byte) 0x62,
+            (byte) 0x46, (byte) 0x17, (byte) 0x11, (byte) 0x4D, (byte) 0x6C, (byte) 0xC4, (byte) 0x7E, (byte) 0x53,
+            (byte) 0xC1, (byte) 0x25, (byte) 0xC7, (byte) 0x9A, (byte) 0x1C, (byte) 0x88, (byte) 0x58, (byte) 0x2C,
+            (byte) 0x89, (byte) 0xDC, (byte) 0x02, (byte) 0x64, (byte) 0x40, (byte) 0x01, (byte) 0x5D, (byte) 0x38,
+            (byte) 0xA5, (byte) 0xE2, (byte) 0xAF, (byte) 0x55, (byte) 0xD5, (byte) 0xEF, (byte) 0x1A, (byte) 0x7C,
+            (byte) 0xA7, (byte) 0x5B, (byte) 0xA6, (byte) 0x6F, (byte) 0x86, (byte) 0x9F, (byte) 0x73, (byte) 0xE6,
+            (byte) 0x0A, (byte) 0xDE, (byte) 0x2B, (byte) 0x99, (byte) 0x4A, (byte) 0x47, (byte) 0x9C, (byte) 0xDF,
+            (byte) 0x09, (byte) 0x76, (byte) 0x9E, (byte) 0x30, (byte) 0x0E, (byte) 0xE4, (byte) 0xB2, (byte) 0x94,
+            (byte) 0xA0, (byte) 0x3B, (byte) 0x34, (byte) 0x1D, (byte) 0x28, (byte) 0x0F, (byte) 0x36, (byte) 0xE3,
+            (byte) 0x23, (byte) 0xB4, (byte) 0x03, (byte) 0xD8, (byte) 0x90, (byte) 0xC8, (byte) 0x3C, (byte) 0xFE,
+            (byte) 0x5E, (byte) 0x32, (byte) 0x24, (byte) 0x50, (byte) 0x1F, (byte) 0x3A, (byte) 0x43, (byte) 0x8A,
+            (byte) 0x96, (byte) 0x41, (byte) 0x74, (byte) 0xAC, (byte) 0x52, (byte) 0x33, (byte) 0xF0, (byte) 0xD9,
+            (byte) 0x29, (byte) 0x80, (byte) 0xB1, (byte) 0x16, (byte) 0xD3, (byte) 0xAB, (byte) 0x91, (byte) 0xB9,
+            (byte) 0x84, (byte) 0x7F, (byte) 0x61, (byte) 0x1E, (byte) 0xCF, (byte) 0xC5, (byte) 0xD1, (byte) 0x56,
+            (byte) 0x3D, (byte) 0xCA, (byte) 0xF4, (byte) 0x05, (byte) 0xC6, (byte) 0xE5, (byte) 0x08, (byte) 0x49};
 
-    public MapleAESOFB(byte[] iv, short mapleVersion) {
+    private final short mapleVersion;
+    private final Cipher cipher;
+    private byte[] iv;
+
+    public MapleAESOFB(InitializationVector iv, short mapleVersion) {
         try {
             cipher = Cipher.getInstance("AES");
             cipher.init(Cipher.ENCRYPT_MODE, skey);
-        } catch (NoSuchAlgorithmException e) {
-            System.out.println("ERROR " + e);
-        } catch (NoSuchPaddingException e) {
-            System.out.println("ERROR " + e);
-        } catch (InvalidKeyException e) {
-            System.out.println("Error initializing the encryption cipher.  Make sure you're using the Unlimited Strength cryptography jar files.");
+        } catch (NoSuchAlgorithmException | NoSuchPaddingException | InvalidKeyException e) {
+            log.warn("Cypher initialization error with skey: {}", skey, e);
+            throw new RuntimeException(e);
         }
-        this.setIv(iv);
+
+        this.iv = iv.getBytes();
         this.mapleVersion = (short) (((mapleVersion >> 8) & 0xFF) | ((mapleVersion << 8) & 0xFF00));
     }
 
-    private void setIv(byte[] iv) {
-        this.iv = iv;
-    }
-
     private static byte[] multiplyBytes(byte[] in, int count, int mul) {
-        byte[] ret = new byte[count * mul];
-        for (int x = 0; x < count * mul; x++) {
+        final int size = count * mul;
+        byte[] ret = new byte[size];
+        for (int x = 0; x < size; x++) {
             ret[x] = in[x % count];
         }
         return ret;
@@ -94,12 +119,8 @@ public class MapleAESOFB {
                 if ((x - start) % myIv.length == 0) {
                     try {
                         byte[] newIv = cipher.doFinal(myIv);
-                        for (int j = 0; j < myIv.length; j++) {
-                            myIv[j] = newIv[j];
-                        }
-                    } catch (IllegalBlockSizeException e) {
-                        e.printStackTrace();
-                    } catch (BadPaddingException e) {
+                        System.arraycopy(newIv, 0, myIv, 0, myIv.length);
+                    } catch (IllegalBlockSizeException | BadPaddingException e) {
                         e.printStackTrace();
                     }
                 }
@@ -138,7 +159,8 @@ public class MapleAESOFB {
     }
 
     public boolean checkPacket(byte[] packet) {
-        return ((((packet[0] ^ iv[2]) & 0xFF) == ((mapleVersion >> 8) & 0xFF)) && (((packet[1] ^ iv[3]) & 0xFF) == (mapleVersion & 0xFF)));
+        return ((((packet[0] ^ iv[2]) & 0xFF) == ((mapleVersion >> 8) & 0xFF)) &&
+                (((packet[1] ^ iv[3]) & 0xFF) == (mapleVersion & 0xFF)));
     }
 
     public boolean checkPacket(int packetHeader) {

src/main/java/tools/MaplePacketCreator.java

@@ -36,6 +36,7 @@ import constants.inventory.ItemConstants;
 import constants.skills.Buccaneer;
 import constants.skills.Corsair;
 import constants.skills.ThunderBreaker;
+import net.netty.InitializationVector;
 import net.opcodes.SendOpcode;
 import net.server.PlayerCoolDownValueHolder;
 import net.server.Server;
@@ -547,14 +548,14 @@ public class MaplePacketCreator {
          * @param recvIv the IV in use by the server for receiving
          * @return
          */
-        public static byte[] getHello(short mapleVersion, byte[] sendIv, byte[] recvIv) {
+        public static byte[] getHello(short mapleVersion, InitializationVector sendIv, InitializationVector recvIv) {
                 final MaplePacketLittleEndianWriter mplew = new MaplePacketLittleEndianWriter(8);
                 mplew.writeShort(0x0E);
                 mplew.writeShort(mapleVersion);
                 mplew.writeShort(1);
                 mplew.write(49);
-                mplew.write(recvIv);
-                mplew.write(sendIv);
+                mplew.write(recvIv.getBytes());
+                mplew.write(sendIv.getBytes());
                 mplew.write(8);
                 return mplew.getPacket();
         }