Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
SecureRandomNumberGenerator |
|
| 1.75;1.75 |
1 | /* | |
2 | * Licensed to the Apache Software Foundation (ASF) under one | |
3 | * or more contributor license agreements. See the NOTICE file | |
4 | * distributed with this work for additional information | |
5 | * regarding copyright ownership. The ASF licenses this file | |
6 | * to you under the Apache License, Version 2.0 (the | |
7 | * "License"); you may not use this file except in compliance | |
8 | * with the License. You may obtain a copy of the License at | |
9 | * | |
10 | * http://www.apache.org/licenses/LICENSE-2.0 | |
11 | * | |
12 | * Unless required by applicable law or agreed to in writing, | |
13 | * software distributed under the License is distributed on an | |
14 | * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY | |
15 | * KIND, either express or implied. See the License for the | |
16 | * specific language governing permissions and limitations | |
17 | * under the License. | |
18 | */ | |
19 | package org.apache.shiro.crypto; | |
20 | ||
21 | import org.apache.shiro.util.ByteSource; | |
22 | ||
23 | import java.security.SecureRandom; | |
24 | ||
25 | /** | |
26 | * Default implementation of the {@link RandomNumberGenerator RandomNumberGenerator} interface, backed by a | |
27 | * {@link SecureRandom SecureRandom} instance. | |
28 | * <p/> | |
29 | * This class is a little easier to use than using the JDK's {@code SecureRandom} class directly. It also | |
30 | * allows for JavaBeans-style of customization, convenient for Shiro's INI configuration or other IoC configuration | |
31 | * mechanism. | |
32 | * | |
33 | * @since 1.1 | |
34 | */ | |
35 | public class SecureRandomNumberGenerator implements RandomNumberGenerator { | |
36 | ||
37 | protected static final int DEFAULT_NEXT_BYTES_SIZE = 16; //16 bytes == 128 bits (a common number in crypto) | |
38 | ||
39 | private int defaultNextBytesSize; | |
40 | private SecureRandom secureRandom; | |
41 | ||
42 | /** | |
43 | * Creates a new instance with a default backing {@link SecureRandom SecureRandom} and a | |
44 | * {@link #getDefaultNextBytesSize() defaultNextBytesSize} of {@code 16}, which equals 128 bits, a size commonly | |
45 | * used in cryptographic algorithms. | |
46 | */ | |
47 | 45 | public SecureRandomNumberGenerator() { |
48 | 45 | this.defaultNextBytesSize = DEFAULT_NEXT_BYTES_SIZE; |
49 | 45 | this.secureRandom = new SecureRandom(); |
50 | 45 | } |
51 | ||
52 | /** | |
53 | * Seeds the backing {@link SecureRandom SecureRandom} instance with additional seed data. | |
54 | * | |
55 | * @param bytes the seed bytes | |
56 | * @see SecureRandom#setSeed(byte[]) | |
57 | */ | |
58 | public void setSeed(byte[] bytes) { | |
59 | 0 | this.secureRandom.setSeed(bytes); |
60 | 0 | } |
61 | ||
62 | /** | |
63 | * Returns the {@link SecureRandom SecureRandom} backing this instance. | |
64 | * | |
65 | * @return the {@link SecureRandom SecureRandom} backing this instance. | |
66 | */ | |
67 | public SecureRandom getSecureRandom() { | |
68 | 0 | return secureRandom; |
69 | } | |
70 | ||
71 | /** | |
72 | * Sets the {@link SecureRandom SecureRandom} to back this instance. | |
73 | * | |
74 | * @param random the {@link SecureRandom SecureRandom} to back this instance. | |
75 | * @throws NullPointerException if the method argument is null | |
76 | */ | |
77 | public void setSecureRandom(SecureRandom random) throws NullPointerException { | |
78 | 1 | if (random == null) { |
79 | 1 | throw new NullPointerException("SecureRandom argument cannot be null."); |
80 | } | |
81 | 0 | this.secureRandom = random; |
82 | 0 | } |
83 | ||
84 | /** | |
85 | * Returns the size of the generated byte array for calls to {@link #nextBytes() nextBytes()}. Defaults to | |
86 | * {@code 16}, which equals 128 bits, a size commonly used in cryptographic algorithms. | |
87 | * | |
88 | * @return the size of the generated byte array for calls to {@link #nextBytes() nextBytes()}. | |
89 | */ | |
90 | public int getDefaultNextBytesSize() { | |
91 | 28 | return defaultNextBytesSize; |
92 | } | |
93 | ||
94 | /** | |
95 | * Sets the size of the generated byte array for calls to {@link #nextBytes() nextBytes()}. Defaults to | |
96 | * {@code 16}, which equals 128 bits, a size commonly used in cryptographic algorithms. | |
97 | * | |
98 | * @param defaultNextBytesSize the size of the generated byte array for calls to {@link #nextBytes() nextBytes()}. | |
99 | * @throws IllegalArgumentException if the argument is 0 or negative | |
100 | */ | |
101 | public void setDefaultNextBytesSize(int defaultNextBytesSize) throws IllegalArgumentException { | |
102 | 3 | if ( defaultNextBytesSize <= 0) { |
103 | 2 | throw new IllegalArgumentException("size value must be a positive integer (1 or larger)"); |
104 | } | |
105 | 1 | this.defaultNextBytesSize = defaultNextBytesSize; |
106 | 1 | } |
107 | ||
108 | public ByteSource nextBytes() { | |
109 | 28 | return nextBytes(getDefaultNextBytesSize()); |
110 | } | |
111 | ||
112 | public ByteSource nextBytes(int numBytes) { | |
113 | 32 | if (numBytes <= 0) { |
114 | 2 | throw new IllegalArgumentException("numBytes argument must be a positive integer (1 or larger)"); |
115 | } | |
116 | 30 | byte[] bytes = new byte[numBytes]; |
117 | 30 | this.secureRandom.nextBytes(bytes); |
118 | 30 | return ByteSource.Util.bytes(bytes); |
119 | } | |
120 | } |