Added XOR Scrambler for Brew data

Very fast obfuscator for brew data so that a client cant easily read it

src/com/dre/brewery/lore/XORUnscrambleStream.java

@@ -0,0 +1,100 @@
+package com.dre.brewery.lore;
+
+import java.io.FilterInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+public class XORUnscrambleStream extends FilterInputStream {
+
+	private final long seed;
+	private SeedInputStream xorStream;
+	private boolean running;
+	private boolean markRunning;
+	private boolean markxor;
+
+	public XORUnscrambleStream(InputStream in, long seed) {
+		super(in);
+		this.seed = seed;
+	}
+
+	public void start() throws IOException {
+		running = true;
+		if (xorStream == null) {
+			short id = (short) (in.read() << 8 | in.read());
+			if (id == 0) {
+				running = false;
+				return;
+			}
+			xorStream = new SeedInputStream(seed ^ id);
+		}
+	}
+
+	public void stop() {
+		running = false;
+	}
+
+	@Override
+	public int read() throws IOException {
+		if (!running) {
+			return in.read();
+		}
+		return (in.read() ^ xorStream.read()) & 0xFF;
+	}
+
+	@Override
+	public int read(byte[] b, int off, int len) throws IOException {
+		if (!running) {
+			return in.read(b, off, len);
+		}
+		len = in.read(b, off, len);
+		for (int i = off; i < len + off; i++) {
+			b[i] ^= xorStream.read();
+		}
+		return len;
+	}
+
+	@Override
+	public long skip(long n) throws IOException {
+		long skipped = in.skip(n);
+		if (running && skipped > 0) {
+			xorStream.skip(skipped);
+		}
+		return skipped;
+	}
+
+	@Override
+	public void close() throws IOException {
+		if (xorStream != null) {
+			xorStream.close();
+			xorStream = null;
+		}
+		running = false;
+		super.close();
+	}
+
+	@Override
+	public boolean markSupported() {
+		return in.markSupported();
+	}
+
+	@Override
+	public synchronized void reset() throws IOException {
+		in.reset();
+		if (markxor) {
+			xorStream.reset();
+		} else {
+			xorStream = null;
+		}
+		running = markRunning;
+	}
+
+	@Override
+	public synchronized void mark(int readlimit) {
+		in.mark(readlimit);
+		if (xorStream != null) {
+			xorStream.mark(readlimit);
+			markxor = true;
+		}
+		markRunning = running;
+	}
+}