com.spooky.mse.u.TransportCipher.java Source code

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Here is the source code for com.spooky.mse.u.TransportCipher.java

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/*
 * Created on 19-Jan-2006
 * Created by Paul Gardner
 * Copyright (C) Azureus Software, Inc, All Rights Reserved.
 *
 * This program 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 2
 * of the License, or (at your option) any later version.
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 */

package com.spooky.mse.u;

import java.nio.ByteBuffer;

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;

import org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.crypto.engines.RC4Engine;
import org.bouncycastle.crypto.params.KeyParameter;

public class TransportCipher {

    private final RC4Engine rc4_engine;

    public TransportCipher(int mode, SecretKeySpec key_spec) {

        rc4_engine = new RC4Engine();

        CipherParameters params = new KeyParameter(key_spec.getEncoded());

        rc4_engine.init(mode == Cipher.ENCRYPT_MODE, params);

        byte[] temp = new byte[1024];

        temp = update(temp);

    }

    public byte[] update(byte[] data) {
        return (update(data, 0, data.length));
    }

    public byte[] update(byte[] data, int offset, int length) {
        byte[] result;

        if (length == 0) {

            // watch out, cipher.update returns NULL with 0 length input

            result = new byte[0];

        } else {

            result = new byte[length];

            rc4_engine.processBytes(data, offset, length, result, 0);
        }

        return (result);
    }

    public ByteBuffer update(ByteBuffer source) {
        ByteBuffer target = ByteBuffer.allocate(source.remaining());
        update(source, target);
        target.flip();
        return target;
    }

    public void update(ByteBuffer source_buffer, ByteBuffer target_buffer) {
        try {
            // TODO: 1.5 supports update( ByteBuffer, ByteBuffer )

            byte[] source_bytes;
            int offset;
            int length = source_buffer.remaining();

            if (source_buffer.hasArray()) {

                source_bytes = source_buffer.array();

                offset = source_buffer.arrayOffset() + source_buffer.position();

            } else {

                source_bytes = new byte[length];

                offset = 0;

                source_buffer.get(source_bytes);
            }

            byte[] target_bytes = update(source_bytes, offset, length);

            source_buffer.position(source_buffer.limit());

            target_buffer.put(target_bytes);

        } catch (Throwable e) {

            throw new RuntimeException(e);
        }
    }

}