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, ByteVectorOr) {
  30   ByteVector lhs(2);
  31   lhs[1] = 0x12;
  32   ByteVector rhs(2);
  33   rhs[1] = 0x03;
  34
  35   EXPECT_EQ(0x13, (*ByteVectorOr(lhs, &rhs))[1]);
  36 }
  37
  38 TEST(ByteVectorTest, ByteVectorMerge) {
  39   ByteVector lhs(2);
  40   lhs[1] = 0x33;
  41   ByteVector rhs(2);
  42   rhs[1] = 0x55;
  43   ByteVector mask(2);
  44   mask[1] = 0x0f;
  45
  46   EXPECT_EQ(0x35, (*ByteVectorMerge(mask, lhs, &rhs))[1]);
  47 }
  48
  49 TEST(ByteVectorTest, ByteVectorGenerator) {
  50   ByteVectorGenerator generator(2u);
  51   ByteVector random_50 = generator.GetWeightedRandomByteVector(PROBABILITY_50);
  52   EXPECT_EQ(random_50.size(), 2u);
  53   ByteVector random_75 = generator.GetWeightedRandomByteVector(PROBABILITY_75);
  54   EXPECT_EQ(random_75.size(), 2u);
  55 }
  56
  57 TEST(ByteVectorTest, HmacByteVectorGenerator) {
  58   HmacByteVectorGenerator generator(1u,
  59       std::string(HmacByteVectorGenerator::kEntropyInputSize, 0x00), "");
  60   ByteVector random_50 = generator.GetWeightedRandomByteVector(PROBABILITY_50);
  61   EXPECT_EQ(random_50.size(), 1u);
  62   EXPECT_EQ(random_50[0], 0x0B);
  63   ByteVector random_75 = generator.GetWeightedRandomByteVector(PROBABILITY_75);
  64   EXPECT_EQ(random_75.size(), 1u);
  65   EXPECT_EQ(random_75[0], 0xdf);
  66 }
  67
  68 TEST(ByteVectorTest, HmacNist) {
  69   // Test case 0 for SHA-256 HMAC_DRBG no reseed tests from
  70   // http://csrc.nist.gov/groups/STM/cavp/
  71   const char entropy[] =
  72       "ca851911349384bffe89de1cbdc46e6831e44d34a4fb935ee285dd14b71a7488";
  73   const char nonce[] = "659ba96c601dc69fc902940805ec0ca8";
  74   const char expected[] =
  75       "e528e9abf2dece54d47c7e75e5fe302149f817ea9fb4bee6f4199697d04d5b89"
  76       "d54fbb978a15b5c443c9ec21036d2460b6f73ebad0dc2aba6e624abf07745bc1"
  77       "07694bb7547bb0995f70de25d6b29e2d3011bb19d27676c07162c8b5ccde0668"
  78       "961df86803482cb37ed6d5c0bb8d50cf1f50d476aa0458bdaba806f48be9dcb8";
  79
  80   std::string entropy_input = HexToString(entropy) + HexToString(nonce);
  81   HmacByteVectorGenerator generator(1024u / 8, entropy_input, "");
  82   generator.GetWeightedRandomByteVector(PROBABILITY_50);
  83   SecondRequest generator2(generator);
  84   ByteVector random_50 = generator2.GetWeightedRandomByteVector(PROBABILITY_50);
  85
  86   EXPECT_EQ(HexToString(expected),
  87       std::string(random_50.begin(), random_50.end()));
  88 }
  89
  90 TEST(ByteVectorTest, WeightedRandomStatistics50) {
  91   ByteVectorGenerator generator(50u);
  92   ByteVector random = generator.GetWeightedRandomByteVector(PROBABILITY_50);
  93   int bit_count = CountBits(random);
  94   // Check bounds on bit counts that are true with 99.999% probability.
  95   EXPECT_GT(bit_count, 155); // Binomial(400, .5) CDF(155) ~= 0.000004
  96   EXPECT_LE(bit_count, 244); // Binomial(400, .5) CDF(244) ~= 0.999996
  97 }
  98
  99 TEST(ByteVectorTest, WeightedRandomStatistics75) {
 100   ByteVectorGenerator generator(50u);
 101   ByteVector random = generator.GetWeightedRandomByteVector(PROBABILITY_75);
 102   int bit_count = CountBits(random);
 103   // Check bounds on bit counts that are true with 99.999% probability.
 104   EXPECT_GT(bit_count, 259); // Binomial(400, .75) CDF(259) ~= 0.000003
 105   EXPECT_LE(bit_count, 337); // Binomial(400, .75) CDF(337) ~= 0.999997
 106 }
 107
 108 TEST(ByteVectorTest, HmacWeightedRandomStatistics50) {
 109   HmacByteVectorGenerator generator(50u,
 110       HmacByteVectorGenerator::GenerateEntropyInput(), "");
 111   ByteVector random = generator.GetWeightedRandomByteVector(PROBABILITY_50);
 112   int bit_count = CountBits(random);
 113   // Check bounds on bit counts that are true with 99.999% probability.
 114   EXPECT_GT(bit_count, 155); // Binomial(400, .5) CDF(155) ~= 0.000004
 115   EXPECT_LE(bit_count, 244); // Binomial(400, .5) CDF(244) ~= 0.999996
 116 }
 117
 118 TEST(ByteVectorTest, HmacWeightedRandomStatistics75) {
 119   HmacByteVectorGenerator generator(50u,
 120       HmacByteVectorGenerator::GenerateEntropyInput(), "");
 121   ByteVector random = generator.GetWeightedRandomByteVector(PROBABILITY_75);
 122   int bit_count = CountBits(random);
 123   // Check bounds on bit counts that are true with 99.999% probability.
 124   EXPECT_GT(bit_count, 259); // Binomial(400, .75) CDF(259) ~= 0.000003
 125   EXPECT_LE(bit_count, 337); // Binomial(400, .75) CDF(337) ~= 0.999997
 126 }
 127
 128 }  // namespace rappor