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 web socket specification version <a
32 * href="http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-10" >draft-ietf-hybi-thewebsocketprotocol-
33 * 10</a>
34 * </p>
35 */
36 public class WebSocketServerHandshaker08 extends WebSocketServerHandshaker {
37
38 public static final String WEBSOCKET_08_ACCEPT_GUID = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
39
40 private final boolean allowExtensions;
41
42 /**
43 * Constructor specifying the destination web socket location
44 *
45 * @param webSocketURL
46 * URL for web socket communications. e.g "ws://myhost.com/mypath".
47 * Subsequent web socket frames will be sent to this URL.
48 * @param subprotocols
49 * CSV of supported protocols
50 * @param allowExtensions
51 * Allow extensions to be used in the reserved bits of the web socket frame
52 * @param maxFramePayloadLength
53 * Maximum allowable frame payload length. Setting this value to your application's
54 * requirement may reduce denial of service attacks using long data frames.
55 */
56 public WebSocketServerHandshaker08(
57 String webSocketURL, String subprotocols, boolean allowExtensions, int maxFramePayloadLength) {
58 super(WebSocketVersion.V08, webSocketURL, subprotocols, maxFramePayloadLength);
59 this.allowExtensions = allowExtensions;
60 }
61
62 /**
63 * <p>
64 * Handle the web socket handshake for the web socket specification <a href=
65 * "http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-08">HyBi version 8 to 10</a>. Version 8, 9 and
66 * 10 share the same wire protocol.
67 * </p>
68 *
69 * <p>
70 * Browser request to the server:
71 * </p>
72 *
73 * <pre>
74 * GET /chat HTTP/1.1
75 * Host: server.example.com
76 * Upgrade: websocket
77 * Connection: Upgrade
78 * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
79 * Sec-WebSocket-Origin: http://example.com
80 * Sec-WebSocket-Protocol: chat, superchat
81 * Sec-WebSocket-Version: 8
82 * </pre>
83 *
84 * <p>
85 * Server response:
86 * </p>
87 *
88 * <pre>
89 * HTTP/1.1 101 Switching Protocols
90 * Upgrade: websocket
91 * Connection: Upgrade
92 * Sec-WebSocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo=
93 * Sec-WebSocket-Protocol: chat
94 * </pre>
95 */
96 @Override
97 protected FullHttpResponse newHandshakeResponse(FullHttpRequest req, HttpHeaders headers) {
98 FullHttpResponse res = new DefaultFullHttpResponse(HTTP_1_1, HttpResponseStatus.SWITCHING_PROTOCOLS);
99
100 if (headers != null) {
101 res.headers().add(headers);
102 }
103
104 String key = req.headers().get(Names.SEC_WEBSOCKET_KEY);
105 if (key == null) {
106 throw new WebSocketHandshakeException("not a WebSocket request: missing key");
107 }
108 String acceptSeed = key + WEBSOCKET_08_ACCEPT_GUID;
109 byte[] sha1 = WebSocketUtil.sha1(acceptSeed.getBytes(CharsetUtil.US_ASCII));
110 String accept = WebSocketUtil.base64(sha1);
111
112 if (logger.isDebugEnabled()) {
113 logger.debug("WebSocket version 08 server handshake key: {}, response: {}", key, accept);
114 }
115
116 res.headers().add(Names.UPGRADE, WEBSOCKET.toLowerCase());
117 res.headers().add(Names.CONNECTION, Names.UPGRADE);
118 res.headers().add(Names.SEC_WEBSOCKET_ACCEPT, accept);
119 String subprotocols = req.headers().get(Names.SEC_WEBSOCKET_PROTOCOL);
120 if (subprotocols != null) {
121 String selectedSubprotocol = selectSubprotocol(subprotocols);
122 if (selectedSubprotocol == null) {
123 if (logger.isDebugEnabled()) {
124 logger.debug("Requested subprotocol(s) not supported: {}", subprotocols);
125 }
126 } else {
127 res.headers().add(Names.SEC_WEBSOCKET_PROTOCOL, selectedSubprotocol);
128 }
129 }
130 return res;
131 }
132
133 @Override
134 protected WebSocketFrameDecoder newWebsocketDecoder() {
135 return new WebSocket08FrameDecoder(true, allowExtensions, maxFramePayloadLength());
136 }
137
138 @Override
139 protected WebSocketFrameEncoder newWebSocketEncoder() {
140 return new WebSocket08FrameEncoder(false);
141 }
142 }