Set up packet codec and channel initialization

src/main/java/client/MapleClient.java

@@ -26,7 +26,6 @@ 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;
@@ -122,9 +121,7 @@ public class MapleClient extends ChannelInboundHandlerAdapter {
         return lastPacket;
     }
 
-    public MapleClient(ClientCyphers cyphers) {
-        this.send = cyphers.getSendCypher();
-        this.receive = cyphers.getReceiveCypher();
+    public MapleClient() {
         this.session = null; // TODO remove once the other constructor is removed
     }
 

src/main/java/net/mina/MaplePacketDecoder.java

@@ -59,7 +59,7 @@ public class MaplePacketDecoder extends CumulativeProtocolDecoder {
         MapleAESOFB rcvdCrypto = client.getReceiveCrypto();
         if (in.remaining() >= 4 && decoderState.packetlength == -1) {
             int packetHeader = in.getInt();
-            if (!rcvdCrypto.checkPacket(packetHeader)) {
+            if (!rcvdCrypto.isValidHeader(packetHeader)) {
                 MapleSessionCoordinator.getInstance().closeSession(session, true);
                 return false;
             }

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

@@ -14,7 +14,7 @@ public class ClientInitializer extends ChannelInitializer<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);
+        socketChannel.pipeline().addLast("PacketCodec", new PacketCodec(ClientCyphers.generateNew()));
+        socketChannel.pipeline().addLast("MapleClient", new MapleClient());
     }
 }

src/main/java/net/netty/PacketCodec.java

@@ -0,0 +1,9 @@
+package net.netty;
+
+import io.netty.channel.CombinedChannelDuplexHandler;
+
+public class PacketCodec extends CombinedChannelDuplexHandler<PacketDecoder, PacketEncoder> {
+    public PacketCodec(ClientCyphers clientCyphers) {
+        super(new PacketDecoder(clientCyphers.getReceiveCypher()), new PacketEncoder(clientCyphers.getSendCypher()));
+    }
+}

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

@@ -19,7 +19,7 @@ public class PacketDecoder extends ReplayingDecoder<Void> {
     protected void decode(ChannelHandlerContext context, ByteBuf in, List<Object> out) {
         final int header = in.readInt();
 
-        if (!receiveCypher.checkPacket(header)) {
+        if (!receiveCypher.isValidHeader(header)) {
             throw new InvalidPacketHeaderException("Attempted to decode a packet with an invalid header", header);
         }
 

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

@@ -4,6 +4,7 @@ import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.handler.codec.MessageToByteEncoder;
 import net.mina.MapleCustomEncryption;
+import net.packet.OutPacket;
 import tools.MapleAESOFB;
 
 public class PacketEncoder extends MessageToByteEncoder<OutPacket> {

src/main/java/tools/MapleAESOFB.java

@@ -158,12 +158,12 @@ public class MapleAESOFB {
         return packetLength;
     }
 
-    public boolean checkPacket(byte[] packet) {
+    private boolean checkPacket(byte[] packet) {
         return ((((packet[0] ^ iv[2]) & 0xFF) == ((mapleVersion >> 8) & 0xFF)) &&
                 (((packet[1] ^ iv[3]) & 0xFF) == (mapleVersion & 0xFF)));
     }
 
-    public boolean checkPacket(int packetHeader) {
+    public boolean isValidHeader(int packetHeader) {
         byte[] packetHeaderBuf = new byte[2];
         packetHeaderBuf[0] = (byte) ((packetHeader >> 24) & 0xFF);
         packetHeaderBuf[1] = (byte) ((packetHeader >> 16) & 0xFF);