1 /*
2 * Copyright 2012 The Netty Project
3 *
4 * The Netty Project licenses this file to you under the Apache License,
5 * version 2.0 (the "License"); you may not use this file except in compliance
6 * with the License. You may obtain a copy of the License at:
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations
14 * under the License.
15 */
16 package io.netty.handler.codec.http.websocketx;
17
18 import io.netty.handler.codec.http.DefaultFullHttpResponse;
19 import io.netty.handler.codec.http.FullHttpRequest;
20 import io.netty.handler.codec.http.FullHttpResponse;
21 import io.netty.handler.codec.http.HttpHeaders;
22 import io.netty.handler.codec.http.HttpHeaders.Names;
23 import io.netty.handler.codec.http.HttpResponseStatus;
24 import io.netty.util.CharsetUtil;
25
26 import static io.netty.handler.codec.http.HttpHeaders.Values.*;
27 import static io.netty.handler.codec.http.HttpVersion.*;
28
29 /**
30 * <p>
31 * Performs server side opening and closing handshakes for <a href="http://netty.io/s/rfc6455">RFC 6455</a>
32 * (originally web socket specification <a href="http://netty.io/s/ws-17">draft-ietf-hybi-thewebsocketprotocol-17</a>).
33 * </p>
34 */
35 public class WebSocketServerHandshaker13 extends WebSocketServerHandshaker {
36
37 public static final String WEBSOCKET_13_ACCEPT_GUID = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
38
39 private final boolean allowExtensions;
40
41 /**
42 * Constructor specifying the destination web socket location
43 *
44 * @param webSocketURL
45 * URL for web socket communications. e.g "ws://myhost.com/mypath". Subsequent web
46 * socket frames will be sent to this URL.
47 * @param subprotocols
48 * CSV of supported protocols
49 * @param allowExtensions
50 * Allow extensions to be used in the reserved bits of the web socket frame
51 * @param maxFramePayloadLength
52 * Maximum allowable frame payload length. Setting this value to your application's
53 * requirement may reduce denial of service attacks using long data frames.
54 */
55 public WebSocketServerHandshaker13(
56 String webSocketURL, String subprotocols, boolean allowExtensions, int maxFramePayloadLength) {
57 super(WebSocketVersion.V13, webSocketURL, subprotocols, maxFramePayloadLength);
58 this.allowExtensions = allowExtensions;
59 }
60
61 /**
62 * <p>
63 * Handle the web socket handshake for the web socket specification <a href=
64 * "http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-17">HyBi versions 13-17</a>. Versions 13-17
65 * share the same wire protocol.
66 * </p>
67 *
68 * <p>
69 * Browser request to the server:
70 * </p>
71 *
72 * <pre>
73 * GET /chat HTTP/1.1
74 * Host: server.example.com
75 * Upgrade: websocket
76 * Connection: Upgrade
77 * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
78 * Sec-WebSocket-Origin: http://example.com
79 * Sec-WebSocket-Protocol: chat, superchat
80 * Sec-WebSocket-Version: 13
81 * </pre>
82 *
83 * <p>
84 * Server response:
85 * </p>
86 *
87 * <pre>
88 * HTTP/1.1 101 Switching Protocols
89 * Upgrade: websocket
90 * Connection: Upgrade
91 * Sec-WebSocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo=
92 * Sec-WebSocket-Protocol: chat
93 * </pre>
94 */
95 @Override
96 protected FullHttpResponse newHandshakeResponse(FullHttpRequest req, HttpHeaders headers) {
97 FullHttpResponse res = new DefaultFullHttpResponse(HTTP_1_1, HttpResponseStatus.SWITCHING_PROTOCOLS);
98 if (headers != null) {
99 res.headers().add(headers);
100 }
101
102 String key = req.headers().get(Names.SEC_WEBSOCKET_KEY);
103 if (key == null) {
104 throw new WebSocketHandshakeException("not a WebSocket request: missing key");
105 }
106 String acceptSeed = key + WEBSOCKET_13_ACCEPT_GUID;
107 byte[] sha1 = WebSocketUtil.sha1(acceptSeed.getBytes(CharsetUtil.US_ASCII));
108 String accept = WebSocketUtil.base64(sha1);
109
110 if (logger.isDebugEnabled()) {
111 logger.debug("WebSocket version 13 server handshake key: {}, response: {}", key, accept);
112 }
113
114 res.headers().add(Names.UPGRADE, WEBSOCKET.toLowerCase());
115 res.headers().add(Names.CONNECTION, Names.UPGRADE);
116 res.headers().add(Names.SEC_WEBSOCKET_ACCEPT, accept);
117 String subprotocols = req.headers().get(Names.SEC_WEBSOCKET_PROTOCOL);
118 if (subprotocols != null) {
119 String selectedSubprotocol = selectSubprotocol(subprotocols);
120 if (selectedSubprotocol == null) {
121 if (logger.isDebugEnabled()) {
122 logger.debug("Requested subprotocol(s) not supported: {}", subprotocols);
123 }
124 } else {
125 res.headers().add(Names.SEC_WEBSOCKET_PROTOCOL, selectedSubprotocol);
126 }
127 }
128 return res;
129 }
130
131 @Override
132 protected WebSocketFrameDecoder newWebsocketDecoder() {
133 return new WebSocket13FrameDecoder(true, allowExtensions, maxFramePayloadLength());
134 }
135
136 @Override
137 protected WebSocketFrameEncoder newWebSocketEncoder() {
138 return new WebSocket13FrameEncoder(false);
139 }
140 }