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 * https://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.netty5.handler.codec.http.websocketx;
17
18 import io.netty5.util.CharsetUtil;
19 import io.netty5.util.concurrent.FastThreadLocal;
20
21 import java.security.MessageDigest;
22 import java.security.NoSuchAlgorithmException;
23 import java.util.Base64;
24 import java.util.concurrent.ThreadLocalRandom;
25
26 /**
27 * A utility class mainly for use by web sockets.
28 */
29 final class WebSocketUtil {
30
31 private static final String V13_ACCEPT_GUID = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
32
33 private static final FastThreadLocal<MessageDigest> SHA1 = new FastThreadLocal<>() {
34 @Override
35 protected MessageDigest initialValue() throws Exception {
36 try {
37 // Try to get a MessageDigest that uses SHA1.
38 // Suppress a warning about weak hash algorithm
39 // since it's defined in https://datatracker.ietf.org/doc/html/rfc6455#section-10.8.
40 return MessageDigest.getInstance("SHA-1"); // lgtm [java/weak-cryptographic-algorithm]
41 } catch (NoSuchAlgorithmException e) {
42 // This shouldn't happen! How old is the computer ?
43 throw new InternalError("SHA-1 not supported on this platform - Outdated ?");
44 }
45 }
46 };
47
48 /**
49 * Performs a SHA-1 hash on the specified data.
50 *
51 * @param data The data to hash
52 * @return the hashed data
53 */
54 static byte[] sha1(byte[] data) {
55 MessageDigest sha1Digest = SHA1.get();
56 sha1Digest.reset();
57 return sha1Digest.digest(data);
58 }
59
60 /**
61 * Performs base64 encoding on the specified data.
62 *
63 * @param data The data to encode
64 * @return an encoded string containing the data
65 */
66 static String base64(byte[] data) {
67 return Base64.getEncoder().encodeToString(data);
68 }
69
70 /**
71 * Creates an arbitrary number of random bytes.
72 *
73 * @param size the number of random bytes to create
74 * @return an array of random bytes
75 */
76 static byte[] randomBytes(int size) {
77 var bytes = new byte[size];
78 ThreadLocalRandom.current().nextBytes(bytes);
79 return bytes;
80 }
81
82 static String calculateV13Accept(String nonce) {
83 String concat = nonce + V13_ACCEPT_GUID;
84 byte[] sha1 = WebSocketUtil.sha1(concat.getBytes(CharsetUtil.US_ASCII));
85 return WebSocketUtil.base64(sha1);
86 }
87
88 private WebSocketUtil() {
89 }
90 }