Home | History | Annotate | Download | only in rappor 
      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
    138