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1 /*
2  * Copyright (C) 2012 The Guava Authors
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
5  * in compliance with the License. You may obtain a copy of the License at
6  *
7  * http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software distributed under the License
10  * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
11  * or implied. See the License for the specific language governing permissions and limitations under
12  * the License.
13  */
14 
15 package com.google.common.hash;
16 
17 import static java.nio.charset.StandardCharsets.UTF_8;
18 
19 import com.google.common.collect.ImmutableSet;
20 import junit.framework.TestCase;
21 
22 /**
23  * Unit tests for {@link SipHashFunction}.
24  *
25  * @author Kurt Alfred Kluever
26  */
27 public class SipHashFunctionTest extends TestCase {
28 
29   // From https://131002.net/siphash/siphash24.c
30   // k = 00 01 02 ...
31   private static final long K0 = 0x0706050403020100L;
32   private static final long K1 = 0x0f0e0d0c0b0a0908L;
33   private static final HashFunction SIP_WITH_KEY = Hashing.sipHash24(K0, K1);
34   private static final HashFunction SIP_WITHOUT_KEY = Hashing.sipHash24();
35 
36   // These constants were originally ported from https://www.131002.net/siphash/siphash24.c. See:
37   // https://github.com/nahi/siphash-java-inline/blob/master/src/test/java/org/jruby/util/SipHashInlineTest.java
38   private static final long[] EXPECTED =
39       new long[] {
40         0x726fdb47dd0e0e31L,
41         0x74f839c593dc67fdL,
42         0x0d6c8009d9a94f5aL,
43         0x85676696d7fb7e2dL,
44         0xcf2794e0277187b7L,
45         0x18765564cd99a68dL,
46         0xcbc9466e58fee3ceL,
47         0xab0200f58b01d137L,
48         0x93f5f5799a932462L,
49         0x9e0082df0ba9e4b0L,
50         0x7a5dbbc594ddb9f3L,
51         0xf4b32f46226bada7L,
52         0x751e8fbc860ee5fbL,
53         0x14ea5627c0843d90L,
54         0xf723ca908e7af2eeL,
55         0xa129ca6149be45e5L,
56         0x3f2acc7f57c29bdbL,
57         0x699ae9f52cbe4794L,
58         0x4bc1b3f0968dd39cL,
59         0xbb6dc91da77961bdL,
60         0xbed65cf21aa2ee98L,
61         0xd0f2cbb02e3b67c7L,
62         0x93536795e3a33e88L,
63         0xa80c038ccd5ccec8L,
64         0xb8ad50c6f649af94L,
65         0xbce192de8a85b8eaL,
66         0x17d835b85bbb15f3L,
67         0x2f2e6163076bcfadL,
68         0xde4daaaca71dc9a5L,
69         0xa6a2506687956571L,
70         0xad87a3535c49ef28L,
71         0x32d892fad841c342L,
72         0x7127512f72f27cceL,
73         0xa7f32346f95978e3L,
74         0x12e0b01abb051238L,
75         0x15e034d40fa197aeL,
76         0x314dffbe0815a3b4L,
77         0x027990f029623981L,
78         0xcadcd4e59ef40c4dL,
79         0x9abfd8766a33735cL,
80         0x0e3ea96b5304a7d0L,
81         0xad0c42d6fc585992L,
82         0x187306c89bc215a9L,
83         0xd4a60abcf3792b95L,
84         0xf935451de4f21df2L,
85         0xa9538f0419755787L,
86         0xdb9acddff56ca510L,
87         0xd06c98cd5c0975ebL,
88         0xe612a3cb9ecba951L,
89         0xc766e62cfcadaf96L,
90         0xee64435a9752fe72L,
91         0xa192d576b245165aL,
92         0x0a8787bf8ecb74b2L,
93         0x81b3e73d20b49b6fL,
94         0x7fa8220ba3b2eceaL,
95         0x245731c13ca42499L,
96         0xb78dbfaf3a8d83bdL,
97         0xea1ad565322a1a0bL,
98         0x60e61c23a3795013L,
99         0x6606d7e446282b93L,
100         0x6ca4ecb15c5f91e1L,
101         0x9f626da15c9625f3L,
102         0xe51b38608ef25f57L,
103         0x958a324ceb064572L
104       };
105 
testVectors()106   public void testVectors() {
107     for (int i = 0; i < EXPECTED.length; ++i) {
108       byte[] msg = new byte[i];
109       for (int j = 0; j < i; ++j) {
110         msg[j] = (byte) j;
111       }
112       assertSip(msg, EXPECTED[i]);
113     }
114   }
115 
116   // This test data comes from "SipHash: a fast short-input PRF", "Appendix A: Test values".
117   // It can be downloaded here: https://131002.net/siphash/siphash.pdf
test15ByteStringFromSipHashPaper()118   public void test15ByteStringFromSipHashPaper() {
119     byte[] message =
120         new byte[] {
121           0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e
122         };
123     long k0 = 0x0706050403020100L;
124     long k1 = 0x0f0e0d0c0b0a0908L;
125 
126     assertEquals(0xa129ca6149be45e5L, Hashing.sipHash24(k0, k1).hashBytes(message).asLong());
127   }
128 
129   // From https://github.com/BrandonHaynes/siphash-csharp/blob/master/tests/Tests.cs
testKnownValues()130   public void testKnownValues() {
131     assertSip(new byte[] {}, 0x726fdb47dd0e0e31L);
132     assertSip(new byte[] {0x61}, 0x2ba3e8e9a71148caL);
133     assertSip(new byte[1000000], 0x28205108397aa742L);
134     assertSip("12345678", 0x02130609caea37ebL);
135     assertSip("abcdef", 0x2a6e77e733c7c05dL);
136     assertSip("SipHash", 0x8325093242a96f60L);
137   }
138 
139   // Test for common pitfall regarding sign extension.
140   // For example: (long) data[i++] | (long) data[i++] << 8 | ...
141   // If data[i] == (byte) 0x80, the first cast will sign-extend it to 0xffffffffffffff80,
142   // masking the remaining seven bytes.
143   // To test this, we give an input where bit 7 is not cleared. For example:
144   // (1) 00 01 02 03 04 05 06 07 80
145   // (2) 00 01 02 03 04 05 06 07 81
146   // (3) 00 01 02 03 04 05 06 07 ff (or anything in between)
147   // A fault implementation will generate collisions for these inputs.
testCollisionsDueToIncorrectSignExtension()148   public void testCollisionsDueToIncorrectSignExtension() {
149     byte[] col1 = new byte[] {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, (byte) 0x80};
150     byte[] col2 = new byte[] {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, (byte) 0x81};
151     byte[] col3 = new byte[] {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, (byte) 0xff};
152 
153     ImmutableSet<HashCode> hashCodes =
154         ImmutableSet.of(
155             SIP_WITH_KEY.hashBytes(col1),
156             SIP_WITH_KEY.hashBytes(col2),
157             SIP_WITH_KEY.hashBytes(col3));
158     assertEquals(3, hashCodes.size());
159   }
160 
testToString()161   public void testToString() {
162     assertEquals("Hashing.sipHash24(" + K0 + ", " + K1 + ")", SIP_WITH_KEY.toString());
163     assertEquals("Hashing.sipHash24(" + K0 + ", " + K1 + ")", SIP_WITHOUT_KEY.toString());
164     assertEquals("Hashing.sipHash24(20, 13)", Hashing.sipHash24(20, 13).toString());
165   }
166 
assertSip(String input, long expected)167   private static void assertSip(String input, long expected) {
168     assertEquals(expected, SIP_WITH_KEY.hashString(input, UTF_8).asLong());
169     assertEquals(expected, SIP_WITH_KEY.newHasher().putString(input, UTF_8).hash().asLong());
170     assertEquals(expected, SIP_WITHOUT_KEY.hashString(input, UTF_8).asLong());
171     assertEquals(expected, SIP_WITHOUT_KEY.newHasher().putString(input, UTF_8).hash().asLong());
172   }
173 
assertSip(byte[] input, long expected)174   private static void assertSip(byte[] input, long expected) {
175     assertEquals(expected, SIP_WITH_KEY.hashBytes(input).asLong());
176     assertEquals(expected, SIP_WITH_KEY.newHasher().putBytes(input).hash().asLong());
177     assertEquals(expected, SIP_WITHOUT_KEY.hashBytes(input).asLong());
178     assertEquals(expected, SIP_WITHOUT_KEY.newHasher().putBytes(input).hash().asLong());
179   }
180 }
181