1/*
2 * Copyright (C) 2009 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * 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,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16package tests.security;
17
18import java.security.NoSuchAlgorithmException;
19import java.security.SecureRandom;
20import java.util.Arrays;
21import java.util.concurrent.Callable;
22import java.util.concurrent.ExecutorCompletionService;
23import java.util.concurrent.ExecutorService;
24import java.util.concurrent.Executors;
25import junit.framework.TestCase;
26
27public abstract class SecureRandomTest extends TestCase {
28
29    private final String algorithmName;
30
31    private int counter = 0;
32
33    protected SecureRandomTest(String name) {
34        this.algorithmName = name;
35    }
36
37    protected void setUp() throws Exception {
38        super.setUp();
39    }
40
41    public void testSecureRandom() {
42        SecureRandom secureRandom1 = null;
43        try {
44            secureRandom1 = SecureRandom.getInstance(algorithmName);
45        } catch (NoSuchAlgorithmException e) {
46            fail(e.getMessage());
47        }
48
49        SecureRandom secureRandom2 = null;
50        try {
51            secureRandom2 = SecureRandom.getInstance(algorithmName);
52        } catch (NoSuchAlgorithmException e) {
53            fail(e.getMessage());
54        }
55
56        byte[] testRandom1 = getRandomBytes(secureRandom1);
57        byte[] testRandom2 = getRandomBytes(secureRandom2);
58
59        assertFalse(Arrays.equals(testRandom1, testRandom2));
60
61
62    }
63
64    private byte[] getRandomBytes(SecureRandom random) {
65        byte[] randomData = new byte[64];
66
67        random.setSeed(System.currentTimeMillis()+counter);
68        counter++;
69
70        random.nextBytes(randomData);
71
72        return randomData;
73    }
74
75
76    public void testSecureRandomThreadSafety() throws Exception {
77        final SecureRandom secureRandom = SecureRandom.getInstance(algorithmName);
78        int threads = 2;
79        ExecutorService executor = Executors.newFixedThreadPool(threads);
80        ExecutorCompletionService ecs = new ExecutorCompletionService(executor);
81        for (int t = 0; t < threads; t++) {
82            ecs.submit(new Callable<Void>() {
83                public Void call () {
84                    for (int i = 0; i < 1000; i++) {
85                        secureRandom.generateSeed(1024);
86                    }
87                    return null;
88                }
89            });
90        }
91        executor.shutdown();
92        for (int i = 0; i < threads; i++) {
93            ecs.take().get();
94        }
95    }
96}
97