1  // Copyright (c) 2020-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 <span.h>
 6  #include <streams.h>
 7  #include <test/fuzz/fuzz.h>
 8  #include <test/fuzz/FuzzedDataProvider.h>
 9  #include <test/fuzz/util.h>
10  #include <util/obfuscation.h>
11  
12  #include <array>
13  #include <cstddef>
14  #include <cstdint>
15  #include <iostream>
16  #include <optional>
17  #include <vector>
18  
19  FUZZ_TARGET(buffered_file)
20  {
21      FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};
22      FuzzedFileProvider fuzzed_file_provider{fuzzed_data_provider};
23      std::optional<BufferedFile> opt_buffered_file;
24      const auto key_bytes{ConsumeFixedLengthByteVector<std::byte>(fuzzed_data_provider, Obfuscation::KEY_SIZE)};
25      AutoFile fuzzed_file{
26          fuzzed_file_provider.open(),
27          Obfuscation{std::span{key_bytes}.first<Obfuscation::KEY_SIZE>()},
28      };
29      try {
30          auto n_buf_size = fuzzed_data_provider.ConsumeIntegralInRange<uint64_t>(0, 4096);
31          auto n_rewind_in = fuzzed_data_provider.ConsumeIntegralInRange<uint64_t>(0, 4096);
32          opt_buffered_file.emplace(fuzzed_file, n_buf_size, n_rewind_in);
33      } catch (const std::ios_base::failure&) {
34      }
35      if (opt_buffered_file && !fuzzed_file.IsNull()) {
36          bool setpos_fail = false;
37          LIMITED_WHILE(fuzzed_data_provider.ConsumeBool(), 100)
38          {
39              CallOneOf(
40                  fuzzed_data_provider,
41                  [&] {
42                      std::array<std::byte, 4096> arr{};
43                      try {
44                          opt_buffered_file->read({arr.data(), fuzzed_data_provider.ConsumeIntegralInRange<size_t>(0, 4096)});
45                      } catch (const std::ios_base::failure&) {
46                      }
47                  },
48                  [&] {
49                      opt_buffered_file->SetLimit(fuzzed_data_provider.ConsumeIntegralInRange<uint64_t>(0, 4096));
50                  },
51                  [&] {
52                      if (!opt_buffered_file->SetPos(fuzzed_data_provider.ConsumeIntegralInRange<uint64_t>(0, 4096))) {
53                          setpos_fail = true;
54                      }
55                  },
56                  [&] {
57                      if (setpos_fail) {
58                          // Calling FindByte(...) after a failed SetPos(...) call may result in an infinite loop.
59                          return;
60                      }
61                      try {
62                          opt_buffered_file->FindByte(std::byte(fuzzed_data_provider.ConsumeIntegral<uint8_t>()));
63                      } catch (const std::ios_base::failure&) {
64                      }
65                  },
66                  [&] {
67                      ReadFromStream(fuzzed_data_provider, *opt_buffered_file);
68                  });
69          }
70          opt_buffered_file->GetPos();
71      }
72  }