WebSocketClientHandshaker10.java

/*
 * Copyright 2010 Red Hat, Inc.
 *
 * Red Hat licenses this file to you 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 org.chililog.server.pubsub.websocket;

import java.net.URI;

import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.handler.codec.http.DefaultHttpRequest;
import org.jboss.netty.handler.codec.http.HttpHeaders.Names;
import org.jboss.netty.handler.codec.http.HttpHeaders.Values;
import org.jboss.netty.handler.codec.http.HttpMethod;
import org.jboss.netty.handler.codec.http.HttpRequest;
import org.jboss.netty.handler.codec.http.HttpResponse;
import org.jboss.netty.handler.codec.http.HttpResponseStatus;
import org.jboss.netty.handler.codec.http.HttpVersion;
import org.jboss.netty.logging.InternalLogger;
import org.jboss.netty.logging.InternalLoggerFactory;
import org.jboss.netty.util.CharsetUtil;

/**
 * <p>
 * Performs client side opening and closing handshakes for web socket
 * specification version <a
 * href="http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-10"
 * >draft-ietf-hybi-thewebsocketprotocol- 10</a>
 * </p>
 * 
 * @author <a href="http://www.jboss.org/netty/">The Netty Project</a>
 */
public class WebSocketClientHandshaker10 extends WebSocketClientHandshaker {

	private static final InternalLogger logger = InternalLoggerFactory.getInstance(WebSocketClientHandshaker10.class);

	public static final String MAGIC_GUID = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";

	private String expectedChallengeResponseString = null;

	private String protocol = null;

	private boolean allowExtensions = false;

	/**
	 * Constructor specifying the destination web socket location and version to
	 * initiate
	 * 
	 * @param webSocketURL
	 *            URL for web socket communications. e.g
	 *            "ws://myhost.com/mypath". Subsequent web socket frames will be
	 *            sent to this URL.
	 * @param version
	 *            Version of web socket specification to use to connect to the
	 *            server
	 * @param subProtocol
	 *            Sub protocol request sent to the server.
	 * @param allowExtensions
	 *            Allow extensions to be used in the reserved bits of the web socket frame
	 */
	public WebSocketClientHandshaker10(URI webSocketURL, WebSocketSpecificationVersion version, String subProtocol,
			boolean allowExtensions) {
		super(webSocketURL, version, subProtocol);
		this.allowExtensions = allowExtensions;
		return;
	}

	/**
	 * /**
	 * <p>
	 * Sends the opening request to the server:
	 * </p>
	 * 
	 * <pre>
	 * GET /chat HTTP/1.1
	 * Host: server.example.com
	 * Upgrade: websocket
	 * Connection: Upgrade
	 * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
	 * Sec-WebSocket-Origin: http://example.com
	 * Sec-WebSocket-Protocol: chat, superchat
	 * Sec-WebSocket-Version: 8
	 * </pre>
	 * 
	 * @param ctx
	 *            Channel context
	 * @param channel
	 *            Channel into which we can write our request
	 */
	@Override
	public void beginOpeningHandshake(ChannelHandlerContext ctx, Channel channel) {
		// Get path
		URI wsURL = this.getWebSocketURL();
		String path = wsURL.getPath();
		if (wsURL.getQuery() != null && wsURL.getQuery().length() > 0) {
			path = wsURL.getPath() + "?" + wsURL.getQuery();
		}

		// Get 16 bit nonce and base 64 encode it
		byte[] nonce = createRandomBytes(16);
		String key = base64Encode(nonce);

		String acceptSeed = key + MAGIC_GUID;
		byte[] sha1 = sha1(acceptSeed.getBytes(CharsetUtil.US_ASCII));
		this.expectedChallengeResponseString = base64Encode(sha1);

		if (logger.isDebugEnabled()) {
			logger.debug(String.format("HyBi10 Client Handshake key: %s. Expected response: %s.", key,
					this.expectedChallengeResponseString));
		}

		// Format request
		HttpRequest request = new DefaultHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.GET, path);
		request.addHeader(Names.UPGRADE, Values.WEBSOCKET.toLowerCase());
		request.addHeader(Names.CONNECTION, Values.UPGRADE);
		request.addHeader(WebSocketServerHandshakerFactory.SEC_WEBSOCKET_KEY, key);
		request.addHeader(Names.HOST, wsURL.getHost());
		request.addHeader(Names.ORIGIN, "http://" + wsURL.getHost());
		if (protocol != null && !protocol.equals("")) {
			request.addHeader(Names.SEC_WEBSOCKET_PROTOCOL, protocol);
		}
		request.addHeader(WebSocketServerHandshakerFactory.SEC_WEBSOCKET_VERSION, "8");

		channel.write(request);

		ctx.getPipeline().replace("encoder", "ws-encoder", new WebSocket08FrameEncoder(true));
		return;
	}

	/**
	 * <p>
	 * Process server response:
	 * </p>
	 * 
	 * <pre>
	 * HTTP/1.1 101 Switching Protocols
	 * Upgrade: websocket
	 * Connection: Upgrade
	 * Sec-WebSocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo=
	 * Sec-WebSocket-Protocol: chat
	 * </pre>
	 * 
	 * @param ctx
	 *            Channel context
	 * @param response
	 *            HTTP response returned from the server for the request sent by
	 *            beginOpeningHandshake00().
	 * @throws WebSocketHandshakeException
	 */
	@Override
	public void endOpeningHandshake(ChannelHandlerContext ctx, HttpResponse response)
			throws WebSocketHandshakeException {
		final HttpResponseStatus status = new HttpResponseStatus(101, "Switching Protocols");

		if (!response.getStatus().equals(status)) {
			throw new WebSocketHandshakeException("Invalid handshake response status: " + response.getStatus());
		}

		String upgrade = response.getHeader(Names.UPGRADE);
		if (upgrade == null || !upgrade.equals(Values.WEBSOCKET.toLowerCase())) {
			throw new WebSocketHandshakeException("Invalid handshake response upgrade: "
					+ response.getHeader(Names.UPGRADE));
		}

		String connection = response.getHeader(Names.CONNECTION);
		if (connection == null || !connection.equals(Values.UPGRADE)) {
			throw new WebSocketHandshakeException("Invalid handshake response connection: "
					+ response.getHeader(Names.CONNECTION));
		}

		String accept = response.getHeader(WebSocketServerHandshakerFactory.SEC_WEBSOCKET_ACCEPT);
		if (accept == null || !accept.equals(this.expectedChallengeResponseString)) {
			throw new WebSocketHandshakeException(String.format("Invalid challenge. Actual: %s. Expected: %s", accept,
					this.expectedChallengeResponseString));
		}

		ctx.getPipeline().replace("decoder", "ws-decoder", new WebSocket08FrameDecoder(false, this.allowExtensions));

		this.setOpenningHandshakeCompleted(true);
		return;
	}

}