001/*
002 * Trident - A Multithreaded Server Alternative
003 * Copyright 2014 The TridentSDK Team
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 *    http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package net.tridentsdk.server.netty.packet;
019
020import io.netty.buffer.ByteBuf;
021import io.netty.channel.ChannelHandlerContext;
022import io.netty.handler.codec.ByteToMessageDecoder;
023import net.tridentsdk.server.netty.ClientConnection;
024
025import java.util.List;
026
027/**
028 * Decrypts incoming packets and forwards the bytes to the PacketDecoder
029 *
030 * @author The TridentSDK Team
031 */
032public class PacketDecrypter extends ByteToMessageDecoder {
033    private ClientConnection connection;
034
035    @Override
036    public void handlerAdded(ChannelHandlerContext context) {
037        this.connection = ClientConnection.connection(context);
038    }
039
040    /* (non-Javadoc)
041     * @see io.netty.handler.codec.ByteToMessageDecoder#decode(io.netty.channel.ChannelHandlerContext,
042     * io.netty.buffer.ByteBuf, java.util.List)
043     */
044    @Override
045    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
046        ByteBuf bufOut = ctx.alloc().buffer(in.readableBytes());
047
048        if (this.connection.isEncryptionEnabled()) {
049            ByteBuf tmpBuf = ctx.alloc().buffer(in.readableBytes());
050
051            in.readBytes(tmpBuf, in.readableBytes());
052            bufOut.writeBytes(this.connection.decrypt(tmpBuf));
053            tmpBuf.release();
054        } else {
055            bufOut.writeBytes(in);
056        }
057
058        out.add(bufOut);
059    }
060}