1 /*
2 * Copyright 2020 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.netty.handler.codec.quic;
17
18 import java.nio.ByteBuffer;
19
20 /**
21 * Creates new connection id instances.
22 */
23 public interface QuicConnectionIdGenerator {
24 /**
25 * Creates a new connection id with the given length. This method may not be supported by
26 * a sign id generator implementation as a sign id generator should always have an input
27 * to sign with, otherwise this method may generate the same id which may cause some
28 * unpredictable issues when we use it.
29 *
30 * @param length the length of the id.
31 * @return the id.
32 */
33 ByteBuffer newId(int length);
34
35 /**
36 * Creates a new connection id with the given length. The given input may be used to sign or
37 * seed the id, or may be ignored (depending on the implementation).
38 *
39 * @param input the input which may be used to generate the id.
40 * @param length the length of the id.
41 * @return the id.
42 */
43 ByteBuffer newId(ByteBuffer input, int length);
44
45 /**
46 * Creates a new connection id with the given length. The given source connection id and destionation connection id
47 * may be used to sign or seed the id, or may be ignored (depending on the implementation).
48 *
49 * @param scid the source connection id which may be used to generate the id.
50 * @param dcid the destination connection id which may be used to generate the id.
51 * @param length the length of the id.
52 * @return the id.
53 */
54 default ByteBuffer newId(ByteBuffer scid, ByteBuffer dcid, int length) {
55 return newId(dcid, length);
56 }
57
58 /**
59 * Returns the maximum length of a connection id.
60 *
61 * @return the maximum length of a connection id that is supported.
62 */
63 int maxConnectionIdLength();
64
65 /**
66 * Returns true if the implementation is idempotent, which means we will get the same id
67 * with the same input ByteBuffer. Otherwise, returns false.
68 *
69 * @return whether the implementation is idempotent.
70 */
71 boolean isIdempotent();
72
73 /**
74 * Return a {@link QuicConnectionIdGenerator} which randomly generates new connection ids.
75 *
76 * @return a {@link QuicConnectionIdGenerator} which randomly generated ids.
77 */
78 static QuicConnectionIdGenerator randomGenerator() {
79 return SecureRandomQuicConnectionIdGenerator.INSTANCE;
80 }
81
82 /**
83 * Return a {@link QuicConnectionIdGenerator} which generates new connection ids by signing the given input.
84 *
85 * @return a {@link QuicConnectionIdGenerator} which generates ids by signing the given input.
86 */
87 static QuicConnectionIdGenerator signGenerator() {
88 return HmacSignQuicConnectionIdGenerator.INSTANCE;
89 }
90 }