components/rappor/byte_vector_utils_unittest.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "components/rappor/byte_vector_utils.h"
   6
   7 #include "base/rand_util.h"
   8 #include "base/strings/string_number_conversions.h"
   9 #include "testing/gtest/include/gtest/gtest.h"
  10
  11 namespace rappor {
  12
  13 namespace {
  14
  15 class SecondRequest : public HmacByteVectorGenerator {
  16  public:
  17   SecondRequest(const HmacByteVectorGenerator& first_request)
  18       : HmacByteVectorGenerator(first_request) {}
  19 };
  20
  21 std::string HexToString(const char* hex) {
  22   ByteVector bv;
  23   base::HexStringToBytes(hex, &bv);
  24   return std::string(bv.begin(), bv.end());
  25 }
  26
  27 }  // namespace
  28
  29 TEST(ByteVectorTest, ByteVectorAnd) {
  30   ByteVector lhs(2);
  31   lhs[1] = 0x12;
  32   ByteVector rhs(2);
  33   rhs[1] = 0x03;
  34
  35   EXPECT_EQ(0x02, (*ByteVectorAnd(lhs, &rhs))[1]);
  36 }
  37
  38 TEST(ByteVectorTest, ByteVectorOr) {
  39   ByteVector lhs(2);
  40   lhs[1] = 0x12;
  41   ByteVector rhs(2);
  42   rhs[1] = 0x03;
  43
  44   EXPECT_EQ(0x13, (*ByteVectorOr(lhs, &rhs))[1]);
  45 }
  46
  47 TEST(ByteVectorTest, ByteVectorMerge) {
  48   ByteVector lhs(2);
  49   lhs[1] = 0x33;
  50   ByteVector rhs(2);
  51   rhs[1] = 0x55;
  52   ByteVector mask(2);
  53   mask[1] = 0x0f;
  54
  55   EXPECT_EQ(0x35, (*ByteVectorMerge(mask, lhs, &rhs))[1]);
  56 }
  57
  58 TEST(ByteVectorTest, ByteVectorGenerator) {
  59   ByteVectorGenerator generator(2u);
  60   ByteVector random_50 = generator.GetWeightedRandomByteVector(PROBABILITY_50);
  61   EXPECT_EQ(random_50.size(), 2u);
  62   ByteVector random_75 = generator.GetWeightedRandomByteVector(PROBABILITY_75);
  63   EXPECT_EQ(random_75.size(), 2u);
  64 }
  65
  66 TEST(ByteVectorTest, HmacByteVectorGenerator) {
  67   HmacByteVectorGenerator generator(1u,
  68       std::string(HmacByteVectorGenerator::kEntropyInputSize, 0x00), "");
  69   ByteVector random_50 = generator.GetWeightedRandomByteVector(PROBABILITY_50);
  70   EXPECT_EQ(random_50.size(), 1u);
  71   EXPECT_EQ(random_50[0], 0x0B);
  72   ByteVector random_75 = generator.GetWeightedRandomByteVector(PROBABILITY_75);
  73   EXPECT_EQ(random_75.size(), 1u);
  74   EXPECT_EQ(random_75[0], 0xdf);
  75 }
  76
  77 TEST(ByteVectorTest, HmacNist) {
  78   // Test case 0 for SHA-256 HMAC_DRBG no reseed tests from
  79   // http://csrc.nist.gov/groups/STM/cavp/
  80   const char entropy[] =
  81       "ca851911349384bffe89de1cbdc46e6831e44d34a4fb935ee285dd14b71a7488";
  82   const char nonce[] = "659ba96c601dc69fc902940805ec0ca8";
  83   const char expected[] =
  84       "e528e9abf2dece54d47c7e75e5fe302149f817ea9fb4bee6f4199697d04d5b89"
  85       "d54fbb978a15b5c443c9ec21036d2460b6f73ebad0dc2aba6e624abf07745bc1"
  86       "07694bb7547bb0995f70de25d6b29e2d3011bb19d27676c07162c8b5ccde0668"
  87       "961df86803482cb37ed6d5c0bb8d50cf1f50d476aa0458bdaba806f48be9dcb8";
  88
  89   std::string entropy_input = HexToString(entropy) + HexToString(nonce);
  90   HmacByteVectorGenerator generator(1024u / 8, entropy_input, "");
  91   generator.GetWeightedRandomByteVector(PROBABILITY_50);
  92   SecondRequest generator2(generator);
  93   ByteVector random_50 = generator2.GetWeightedRandomByteVector(PROBABILITY_50);
  94
  95   EXPECT_EQ(HexToString(expected),
  96       std::string(random_50.begin(), random_50.end()));
  97 }
  98
  99 TEST(ByteVectorTest, WeightedRandomStatistics50) {
 100   ByteVectorGenerator generator(50u);
 101   ByteVector random = generator.GetWeightedRandomByteVector(PROBABILITY_50);
 102   int bit_count = CountBits(random);
 103   // Check bounds on bit counts that are true with 99.999% probability.
 104   EXPECT_GT(bit_count, 155); // Binomial(400, .5) CDF(155) ~= 0.000004
 105   EXPECT_LE(bit_count, 244); // Binomial(400, .5) CDF(244) ~= 0.999996
 106 }
 107
 108 TEST(ByteVectorTest, WeightedRandomStatistics75) {
 109   ByteVectorGenerator generator(50u);
 110   ByteVector random = generator.GetWeightedRandomByteVector(PROBABILITY_75);
 111   int bit_count = CountBits(random);
 112   // Check bounds on bit counts that are true with 99.999% probability.
 113   EXPECT_GT(bit_count, 259); // Binomial(400, .75) CDF(259) ~= 0.000003
 114   EXPECT_LE(bit_count, 337); // Binomial(400, .75) CDF(337) ~= 0.999997
 115 }
 116
 117 TEST(ByteVectorTest, HmacWeightedRandomStatistics50) {
 118   HmacByteVectorGenerator generator(50u,
 119       HmacByteVectorGenerator::GenerateEntropyInput(), "");
 120   ByteVector random = generator.GetWeightedRandomByteVector(PROBABILITY_50);
 121   int bit_count = CountBits(random);
 122   // Check bounds on bit counts that are true with 99.999% probability.
 123   EXPECT_GT(bit_count, 155); // Binomial(400, .5) CDF(155) ~= 0.000004
 124   EXPECT_LE(bit_count, 244); // Binomial(400, .5) CDF(244) ~= 0.999996
 125 }
 126
 127 TEST(ByteVectorTest, HmacWeightedRandomStatistics75) {
 128   HmacByteVectorGenerator generator(50u,
 129       HmacByteVectorGenerator::GenerateEntropyInput(), "");
 130   ByteVector random = generator.GetWeightedRandomByteVector(PROBABILITY_75);
 131   int bit_count = CountBits(random);
 132   // Check bounds on bit counts that are true with 99.999% probability.
 133   EXPECT_GT(bit_count, 259); // Binomial(400, .75) CDF(259) ~= 0.000003
 134   EXPECT_LE(bit_count, 337); // Binomial(400, .75) CDF(337) ~= 0.999997
 135 }
 136
 137 }  // namespace rappor