1  // Copyright (c) 2021-present The Bitcoin Core developers
 2  // Distributed under the MIT software license, see the accompanying
 3  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 4  
 5  #include <minisketch.h>
 6  #include <node/minisketchwrapper.h>
 7  #include <test/fuzz/FuzzedDataProvider.h>
 8  #include <test/fuzz/fuzz.h>
 9  #include <test/fuzz/util.h>
10  #include <util/check.h>
11  
12  #include <map>
13  #include <numeric>
14  
15  namespace {
16  
17  Minisketch MakeFuzzMinisketch32(size_t capacity, uint32_t impl)
18  {
19      return Assert(Minisketch(32, impl, capacity));
20  }
21  
22  } // namespace
23  
24  FUZZ_TARGET(minisketch)
25  {
26      FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};
27  
28      const auto capacity{fuzzed_data_provider.ConsumeIntegralInRange<size_t>(1, 200)};
29      const uint32_t impl{fuzzed_data_provider.ConsumeIntegralInRange<uint32_t>(0, Minisketch::MaxImplementation())};
30      if (!Minisketch::ImplementationSupported(32, impl)) return;
31  
32      Minisketch sketch_a{MakeFuzzMinisketch32(capacity, impl)};
33      Minisketch sketch_b{MakeFuzzMinisketch32(capacity, impl)};
34      sketch_a.SetSeed(fuzzed_data_provider.ConsumeIntegral<uint64_t>());
35      sketch_b.SetSeed(fuzzed_data_provider.ConsumeIntegral<uint64_t>());
36  
37      // Fill two sets and keep the difference in a map
38      std::map<uint32_t, bool> diff;
39      LIMITED_WHILE(fuzzed_data_provider.ConsumeBool(), 10000)
40      {
41          const auto entry{fuzzed_data_provider.ConsumeIntegralInRange<uint32_t>(1, std::numeric_limits<uint32_t>::max() - 1)};
42          const auto KeepDiff{[&] {
43              bool& mut{diff[entry]};
44              mut = !mut;
45          }};
46          CallOneOf(
47              fuzzed_data_provider,
48              [&] {
49                  sketch_a.Add(entry);
50                  KeepDiff();
51              },
52              [&] {
53                  sketch_b.Add(entry);
54                  KeepDiff();
55              },
56              [&] {
57                  sketch_a.Add(entry);
58                  sketch_b.Add(entry);
59              });
60      }
61      const auto num_diff{std::accumulate(diff.begin(), diff.end(), size_t{0}, [](auto n, const auto& e) { return n + e.second; })};
62  
63      Minisketch sketch_ar{MakeFuzzMinisketch32(capacity, impl)};
64      Minisketch sketch_br{MakeFuzzMinisketch32(capacity, impl)};
65      sketch_ar.SetSeed(fuzzed_data_provider.ConsumeIntegral<uint64_t>());
66      sketch_br.SetSeed(fuzzed_data_provider.ConsumeIntegral<uint64_t>());
67  
68      sketch_ar.Deserialize(sketch_a.Serialize());
69      sketch_br.Deserialize(sketch_b.Serialize());
70  
71      Minisketch sketch_diff{std::move(fuzzed_data_provider.ConsumeBool() ? sketch_a : sketch_ar)};
72      sketch_diff.Merge(fuzzed_data_provider.ConsumeBool() ? sketch_b : sketch_br);
73  
74      if (capacity >= num_diff) {
75          const auto max_elements{fuzzed_data_provider.ConsumeIntegralInRange<size_t>(num_diff, capacity)};
76          const auto dec{*Assert(sketch_diff.Decode(max_elements))};
77          Assert(dec.size() == num_diff);
78          for (auto d : dec) {
79              Assert(diff.at(d));
80          }
81      }
82  }