/*
* JBoss, Home of Professional Open Source.
* Copyright 2014 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.undertow.websockets.core.protocol.version07;
import io.undertow.server.protocol.framed.FrameHeaderData;
import io.undertow.websockets.core.function.ChannelFunction;
import java.nio.ByteBuffer;
/**
* @author <a href="mailto:nmaurer@redhat.com">Norman Maurer</a>
*/
public final class Masker implements ChannelFunction {
private byte[] maskingKey;
int m;
Masker(int maskingKey) {
this.maskingKey = createsMaskingKey(maskingKey);
}
public void setMaskingKey(int maskingKey) {
this.maskingKey = createsMaskingKey(maskingKey);
m = 0;
}
private static byte[] createsMaskingKey(int maskingKey) {
byte[] key = new byte[4];
key[0] = (byte) (maskingKey >> 24 & 0xFF);
key[1] = (byte) (maskingKey >> 16 & 0xFF);
key[2] = (byte) (maskingKey >> 8 & 0xFF);
key[3] = (byte) (maskingKey & 0xFF);
return key;
}
private void mask(ByteBuffer buf, int position, int length) {
int limit = position + length;
for (int i = position ; i < limit; ++i) {
buf.put(i, (byte) (buf.get(i) ^ maskingKey[m++]));
m %= 4;
}
}
@Override
public void newFrame(FrameHeaderData headerData) {
WebSocket07Channel.WebSocketFrameHeader header = (WebSocket07Channel.WebSocketFrameHeader) headerData;
setMaskingKey(header.getMaskingKey());
}
@Override
public void afterRead(ByteBuffer buf, int position, int length) {
mask(buf, position, length);
}
@Override
public void beforeWrite(ByteBuffer buf, int position, int length) {
mask(buf, position, length);
}
@Override
public void complete() {
// noop
}
}