xref: /aosp_15_r20/external/abseil-cpp/absl/random/seed_sequences_test.cc (revision 9356374a3709195abf420251b3e825997ff56c0f)
1*9356374aSAndroid Build Coastguard Worker // Copyright 2017 The Abseil Authors.
2*9356374aSAndroid Build Coastguard Worker //
3*9356374aSAndroid Build Coastguard Worker // Licensed under the Apache License, Version 2.0 (the "License");
4*9356374aSAndroid Build Coastguard Worker // you may not use this file except in compliance with the License.
5*9356374aSAndroid Build Coastguard Worker // You may obtain a copy of the License at
6*9356374aSAndroid Build Coastguard Worker //
7*9356374aSAndroid Build Coastguard Worker //      https://www.apache.org/licenses/LICENSE-2.0
8*9356374aSAndroid Build Coastguard Worker //
9*9356374aSAndroid Build Coastguard Worker // Unless required by applicable law or agreed to in writing, software
10*9356374aSAndroid Build Coastguard Worker // distributed under the License is distributed on an "AS IS" BASIS,
11*9356374aSAndroid Build Coastguard Worker // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12*9356374aSAndroid Build Coastguard Worker // See the License for the specific language governing permissions and
13*9356374aSAndroid Build Coastguard Worker // limitations under the License.
14*9356374aSAndroid Build Coastguard Worker 
15*9356374aSAndroid Build Coastguard Worker #include "absl/random/seed_sequences.h"
16*9356374aSAndroid Build Coastguard Worker 
17*9356374aSAndroid Build Coastguard Worker #include <iterator>
18*9356374aSAndroid Build Coastguard Worker #include <random>
19*9356374aSAndroid Build Coastguard Worker 
20*9356374aSAndroid Build Coastguard Worker #include "gmock/gmock.h"
21*9356374aSAndroid Build Coastguard Worker #include "gtest/gtest.h"
22*9356374aSAndroid Build Coastguard Worker #include "absl/random/internal/nonsecure_base.h"
23*9356374aSAndroid Build Coastguard Worker #include "absl/random/random.h"
24*9356374aSAndroid Build Coastguard Worker namespace {
25*9356374aSAndroid Build Coastguard Worker 
TEST(SeedSequences,Examples)26*9356374aSAndroid Build Coastguard Worker TEST(SeedSequences, Examples) {
27*9356374aSAndroid Build Coastguard Worker   {
28*9356374aSAndroid Build Coastguard Worker     absl::SeedSeq seed_seq({1, 2, 3});
29*9356374aSAndroid Build Coastguard Worker     absl::BitGen bitgen(seed_seq);
30*9356374aSAndroid Build Coastguard Worker 
31*9356374aSAndroid Build Coastguard Worker     EXPECT_NE(0, bitgen());
32*9356374aSAndroid Build Coastguard Worker   }
33*9356374aSAndroid Build Coastguard Worker   {
34*9356374aSAndroid Build Coastguard Worker     absl::BitGen engine;
35*9356374aSAndroid Build Coastguard Worker     auto seed_seq = absl::CreateSeedSeqFrom(&engine);
36*9356374aSAndroid Build Coastguard Worker     absl::BitGen bitgen(seed_seq);
37*9356374aSAndroid Build Coastguard Worker 
38*9356374aSAndroid Build Coastguard Worker     EXPECT_NE(engine(), bitgen());
39*9356374aSAndroid Build Coastguard Worker   }
40*9356374aSAndroid Build Coastguard Worker   {
41*9356374aSAndroid Build Coastguard Worker     auto seed_seq = absl::MakeSeedSeq();
42*9356374aSAndroid Build Coastguard Worker     std::mt19937 random(seed_seq);
43*9356374aSAndroid Build Coastguard Worker 
44*9356374aSAndroid Build Coastguard Worker     EXPECT_NE(0, random());
45*9356374aSAndroid Build Coastguard Worker   }
46*9356374aSAndroid Build Coastguard Worker }
47*9356374aSAndroid Build Coastguard Worker 
TEST(CreateSeedSeqFrom,CompatibleWithStdTypes)48*9356374aSAndroid Build Coastguard Worker TEST(CreateSeedSeqFrom, CompatibleWithStdTypes) {
49*9356374aSAndroid Build Coastguard Worker   using ExampleNonsecureURBG =
50*9356374aSAndroid Build Coastguard Worker       absl::random_internal::NonsecureURBGBase<std::minstd_rand0>;
51*9356374aSAndroid Build Coastguard Worker 
52*9356374aSAndroid Build Coastguard Worker   // Construct a URBG instance.
53*9356374aSAndroid Build Coastguard Worker   ExampleNonsecureURBG rng;
54*9356374aSAndroid Build Coastguard Worker 
55*9356374aSAndroid Build Coastguard Worker   // Construct a Seed Sequence from its variates.
56*9356374aSAndroid Build Coastguard Worker   auto seq_from_rng = absl::CreateSeedSeqFrom(&rng);
57*9356374aSAndroid Build Coastguard Worker 
58*9356374aSAndroid Build Coastguard Worker   // Ensure that another URBG can be validly constructed from the Seed Sequence.
59*9356374aSAndroid Build Coastguard Worker   std::mt19937_64{seq_from_rng};
60*9356374aSAndroid Build Coastguard Worker }
61*9356374aSAndroid Build Coastguard Worker 
TEST(CreateSeedSeqFrom,CompatibleWithBitGenerator)62*9356374aSAndroid Build Coastguard Worker TEST(CreateSeedSeqFrom, CompatibleWithBitGenerator) {
63*9356374aSAndroid Build Coastguard Worker   // Construct a URBG instance.
64*9356374aSAndroid Build Coastguard Worker   absl::BitGen rng;
65*9356374aSAndroid Build Coastguard Worker 
66*9356374aSAndroid Build Coastguard Worker   // Construct a Seed Sequence from its variates.
67*9356374aSAndroid Build Coastguard Worker   auto seq_from_rng = absl::CreateSeedSeqFrom(&rng);
68*9356374aSAndroid Build Coastguard Worker 
69*9356374aSAndroid Build Coastguard Worker   // Ensure that another URBG can be validly constructed from the Seed Sequence.
70*9356374aSAndroid Build Coastguard Worker   std::mt19937_64{seq_from_rng};
71*9356374aSAndroid Build Coastguard Worker }
72*9356374aSAndroid Build Coastguard Worker 
TEST(CreateSeedSeqFrom,CompatibleWithInsecureBitGen)73*9356374aSAndroid Build Coastguard Worker TEST(CreateSeedSeqFrom, CompatibleWithInsecureBitGen) {
74*9356374aSAndroid Build Coastguard Worker   // Construct a URBG instance.
75*9356374aSAndroid Build Coastguard Worker   absl::InsecureBitGen rng;
76*9356374aSAndroid Build Coastguard Worker 
77*9356374aSAndroid Build Coastguard Worker   // Construct a Seed Sequence from its variates.
78*9356374aSAndroid Build Coastguard Worker   auto seq_from_rng = absl::CreateSeedSeqFrom(&rng);
79*9356374aSAndroid Build Coastguard Worker 
80*9356374aSAndroid Build Coastguard Worker   // Ensure that another URBG can be validly constructed from the Seed Sequence.
81*9356374aSAndroid Build Coastguard Worker   std::mt19937_64{seq_from_rng};
82*9356374aSAndroid Build Coastguard Worker }
83*9356374aSAndroid Build Coastguard Worker 
TEST(CreateSeedSeqFrom,CompatibleWithRawURBG)84*9356374aSAndroid Build Coastguard Worker TEST(CreateSeedSeqFrom, CompatibleWithRawURBG) {
85*9356374aSAndroid Build Coastguard Worker   // Construct a URBG instance.
86*9356374aSAndroid Build Coastguard Worker   std::random_device urandom;
87*9356374aSAndroid Build Coastguard Worker 
88*9356374aSAndroid Build Coastguard Worker   // Construct a Seed Sequence from its variates, using 64b of seed-material.
89*9356374aSAndroid Build Coastguard Worker   auto seq_from_rng = absl::CreateSeedSeqFrom(&urandom);
90*9356374aSAndroid Build Coastguard Worker 
91*9356374aSAndroid Build Coastguard Worker   // Ensure that another URBG can be validly constructed from the Seed Sequence.
92*9356374aSAndroid Build Coastguard Worker   std::mt19937_64{seq_from_rng};
93*9356374aSAndroid Build Coastguard Worker }
94*9356374aSAndroid Build Coastguard Worker 
95*9356374aSAndroid Build Coastguard Worker template <typename URBG>
TestReproducibleVariateSequencesForNonsecureURBG()96*9356374aSAndroid Build Coastguard Worker void TestReproducibleVariateSequencesForNonsecureURBG() {
97*9356374aSAndroid Build Coastguard Worker   const size_t kNumVariates = 1000;
98*9356374aSAndroid Build Coastguard Worker 
99*9356374aSAndroid Build Coastguard Worker   URBG rng;
100*9356374aSAndroid Build Coastguard Worker   // Reused for both RNG instances.
101*9356374aSAndroid Build Coastguard Worker   auto reusable_seed = absl::CreateSeedSeqFrom(&rng);
102*9356374aSAndroid Build Coastguard Worker 
103*9356374aSAndroid Build Coastguard Worker   typename URBG::result_type variates[kNumVariates];
104*9356374aSAndroid Build Coastguard Worker   {
105*9356374aSAndroid Build Coastguard Worker     URBG child(reusable_seed);
106*9356374aSAndroid Build Coastguard Worker     for (auto& variate : variates) {
107*9356374aSAndroid Build Coastguard Worker       variate = child();
108*9356374aSAndroid Build Coastguard Worker     }
109*9356374aSAndroid Build Coastguard Worker   }
110*9356374aSAndroid Build Coastguard Worker   // Ensure that variate-sequence can be "replayed" by identical RNG.
111*9356374aSAndroid Build Coastguard Worker   {
112*9356374aSAndroid Build Coastguard Worker     URBG child(reusable_seed);
113*9356374aSAndroid Build Coastguard Worker     for (auto& variate : variates) {
114*9356374aSAndroid Build Coastguard Worker       ASSERT_EQ(variate, child());
115*9356374aSAndroid Build Coastguard Worker     }
116*9356374aSAndroid Build Coastguard Worker   }
117*9356374aSAndroid Build Coastguard Worker }
118*9356374aSAndroid Build Coastguard Worker 
TEST(CreateSeedSeqFrom,ReproducesVariateSequencesForInsecureBitGen)119*9356374aSAndroid Build Coastguard Worker TEST(CreateSeedSeqFrom, ReproducesVariateSequencesForInsecureBitGen) {
120*9356374aSAndroid Build Coastguard Worker   TestReproducibleVariateSequencesForNonsecureURBG<absl::InsecureBitGen>();
121*9356374aSAndroid Build Coastguard Worker }
122*9356374aSAndroid Build Coastguard Worker 
TEST(CreateSeedSeqFrom,ReproducesVariateSequencesForBitGenerator)123*9356374aSAndroid Build Coastguard Worker TEST(CreateSeedSeqFrom, ReproducesVariateSequencesForBitGenerator) {
124*9356374aSAndroid Build Coastguard Worker   TestReproducibleVariateSequencesForNonsecureURBG<absl::BitGen>();
125*9356374aSAndroid Build Coastguard Worker }
126*9356374aSAndroid Build Coastguard Worker }  // namespace
127