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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 com.google.common.base.Charsets.UTF_8;
     18 
     19 import com.google.common.collect.ImmutableSet;
     20 
     21 import junit.framework.TestCase;
     22 
     23 /**
     24  * Unit tests for {@link SipHashFunction}.
     25  *
     26  * @author Kurt Alfred Kluever
     27  */
     28 public class SipHashFunctionTest extends TestCase {
     29 
     30   // From https://131002.net/siphash/siphash24.c
     31   // k = 00 01 02 ...
     32   private static final long K0 = 0x0706050403020100L;
     33   private static final long K1 = 0x0f0e0d0c0b0a0908L;
     34   private static final HashFunction SIP_WITH_KEY = Hashing.sipHash24(K0, K1);
     35   private static final HashFunction SIP_WITHOUT_KEY = Hashing.sipHash24();
     36 
     37   // These constants were originally ported from https://www.131002.net/siphash/siphash24.c. See:
     38   // https://github.com/nahi/siphash-java-inline/blob/master/src/test/java/SipHashInlineTest.java
     39   private static final long[] EXPECTED = 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 
    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
    118   public void test15ByteStringFromSipHashPaper() {
    119     byte[] message = new byte[] {
    120         0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e };
    121     long k0 = 0x0706050403020100L;
    122     long k1 = 0x0f0e0d0c0b0a0908L;
    123 
    124     assertEquals(0xa129ca6149be45e5L, Hashing.sipHash24(k0, k1).hashBytes(message).asLong());
    125   }
    126 
    127   // From https://github.com/BrandonHaynes/siphash-csharp/blob/master/tests/Tests.cs
    128   public void testKnownValues() {
    129     assertSip(new byte[] { }, 0x726fdb47dd0e0e31L);
    130     assertSip(new byte[] { 0x61 }, 0x2ba3e8e9a71148caL);
    131     assertSip(new byte[1000000], 0x28205108397aa742L);
    132     assertSip("12345678", 0x02130609caea37ebL);
    133     assertSip("abcdef", 0x2a6e77e733c7c05dL);
    134     assertSip("SipHash", 0x8325093242a96f60L);
    135   }
    136 
    137   // Test for common pitfall regarding sign extension.
    138   // For example: (long) data[i++] | (long) data[i++] << 8 | ...
    139   // If data[i] == (byte) 0x80, the first cast will sign-extend it to 0xffffffffffffff80,
    140   // masking the remaining seven bytes.
    141   // To test this, we give an input where bit 7 is not cleared. For example:
    142   // (1) 00 01 02 03 04 05 06 07 80
    143   // (2) 00 01 02 03 04 05 06 07 81
    144   // (3) 00 01 02 03 04 05 06 07 ff (or anything in between)
    145   // A fault implementation will generate collisions for these inputs.
    146   public void testCollisionsDueToIncorrectSignExtension() {
    147     byte[] col1 = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, (byte) 0x80 };
    148     byte[] col2 = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, (byte) 0x81 };
    149     byte[] col3 = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, (byte) 0xff };
    150 
    151     ImmutableSet<HashCode> hashCodes = ImmutableSet.of(
    152         SIP_WITH_KEY.hashBytes(col1),
    153         SIP_WITH_KEY.hashBytes(col2),
    154         SIP_WITH_KEY.hashBytes(col3));
    155     assertEquals(3, hashCodes.size());
    156   }
    157 
    158   public void testToString() {
    159     assertEquals("Hashing.sipHash24(" + K0 + ", " + K1 + ")", SIP_WITH_KEY.toString());
    160     assertEquals("Hashing.sipHash24(" + K0 + ", " + K1 + ")", SIP_WITHOUT_KEY.toString());
    161     assertEquals("Hashing.sipHash24(20, 13)", Hashing.sipHash24(20, 13).toString());
    162   }
    163 
    164   private static void assertSip(String input, long expected) {
    165     assertEquals(expected, SIP_WITH_KEY.hashString(input, UTF_8).asLong());
    166     assertEquals(expected, SIP_WITH_KEY.newHasher().putString(input, UTF_8).hash().asLong());
    167     assertEquals(expected, SIP_WITHOUT_KEY.hashString(input, UTF_8).asLong());
    168     assertEquals(expected, SIP_WITHOUT_KEY.newHasher().putString(input, UTF_8).hash().asLong());
    169   }
    170 
    171   private static void assertSip(byte[] input, long expected) {
    172     assertEquals(expected, SIP_WITH_KEY.hashBytes(input).asLong());
    173     assertEquals(expected, SIP_WITH_KEY.newHasher().putBytes(input).hash().asLong());
    174     assertEquals(expected, SIP_WITHOUT_KEY.hashBytes(input).asLong());
    175     assertEquals(expected, SIP_WITHOUT_KEY.newHasher().putBytes(input).hash().asLong());
    176   }
    177 }
    178