org.diorite.impl.connection.packets.PacketEncryptionHandler.java Source code

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Here is the source code for org.diorite.impl.connection.packets.PacketEncryptionHandler.java

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/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2016. Diorite (by Bartomiej Mazur (aka GotoFinal))
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

package org.diorite.impl.connection.packets;

import javax.crypto.Cipher;
import javax.crypto.ShortBufferException;

import org.apache.commons.lang3.builder.ToStringBuilder;
import org.apache.commons.lang3.builder.ToStringStyle;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;

public class PacketEncryptionHandler {
    private static final byte[] EMPTY_BYTES = new byte[0];
    private final Cipher cipher;
    private byte[] b = EMPTY_BYTES;
    private byte[] c = EMPTY_BYTES;

    protected PacketEncryptionHandler(final Cipher cipher) {
        this.cipher = cipher;
    }

    private byte[] getBytes(final ByteBuf byteBuf) {
        final int readableBytes = byteBuf.readableBytes();
        if (this.b.length < readableBytes) {
            this.b = new byte[readableBytes];
        }
        byteBuf.readBytes(this.b, 0, readableBytes);
        return this.b;
    }

    protected ByteBuf handle(final ChannelHandlerContext channelHandlerContext, final ByteBuf byteBuf)
            throws ShortBufferException {
        final int readableBytes = byteBuf.readableBytes();
        final byte[] arrayOfByte = this.getBytes(byteBuf);

        final ByteBuf newBuf = channelHandlerContext.alloc().heapBuffer(this.cipher.getOutputSize(readableBytes));
        newBuf.writerIndex(this.cipher.update(arrayOfByte, 0, readableBytes, newBuf.array(), newBuf.arrayOffset()));

        return newBuf;
    }

    protected void copy(final ByteBuf srcByteBuf, final ByteBuf byteBuf) throws ShortBufferException {
        final int readableBytes = srcByteBuf.readableBytes();
        final byte[] bytes = this.getBytes(srcByteBuf);

        final int outputSize = this.cipher.getOutputSize(readableBytes);
        if (this.c.length < outputSize) {
            this.c = new byte[outputSize];
        }
        byteBuf.writeBytes(this.c, 0, this.cipher.update(bytes, 0, readableBytes, this.c));
    }

    @Override
    public String toString() {
        return new ToStringBuilder(this, ToStringStyle.SHORT_PREFIX_STYLE).appendSuper(super.toString())
                .append("cipher", this.cipher).toString();
    }
}