com.rs3e.utility.ByteBufUtils.java Source code

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Here is the source code for com.rs3e.utility.ByteBufUtils.java

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/*
 * This file is part of RS3Emulation.
 *
 * RS3Emulation is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * RS3Emulation is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with RS3Emulation.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.rs3e.utility;

import java.math.BigInteger;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;

/**
 * 
 * RS3Emulation
 * ByteBufUtils.java
 * Mar 11, 2014
 * @author Im Frizzy : Kyle Friz : <skype:kfriz1998>
 */
public final class ByteBufUtils {

    public static ByteBuf rsa(ByteBuf buf, String modulus, String exponent) {
        byte[] bytes = new byte[buf.readableBytes()];
        buf.readBytes(bytes);

        BigInteger cipherText = new BigInteger(bytes);
        BigInteger mod = new BigInteger(modulus);
        BigInteger exp = new BigInteger(exponent);
        BigInteger plainText = cipherText.modPow(exp, mod);

        return Unpooled.wrappedBuffer(plainText.toByteArray());
    }

    public static String readString(ByteBuf buffer) {
        buffer.markReaderIndex();

        int len = 0;
        while (buffer.readUnsignedByte() != 0)
            len++;

        buffer.resetReaderIndex();

        byte[] bytes = new byte[len];
        buffer.readBytes(bytes);
        buffer.readerIndex(buffer.readerIndex() + 1);
        return new String(bytes, Charsets.ASCII_LATIN1_CHARSET);
    }

    public static void writeString(ByteBuf buffer, String str) {
        byte[] bytes = str.getBytes(Charsets.ASCII_LATIN1_CHARSET);
        buffer.writeBytes(bytes);
        buffer.writeByte(0);
    }

    public static void writeSmart(ByteBuf buffer, int value) {
        if (value < 128)
            buffer.writeByte(value);
        else
            buffer.writeShort(32768 + value);
    }

    public static void writeWorldListString(ByteBuf buffer, String str) {
        buffer.writeByte(0);
        buffer.writeBytes(str.getBytes(Charsets.ASCII_LATIN1_CHARSET));
        buffer.writeByte(0);
    }

    private ByteBufUtils() {

    }

}