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 <primitives/block.h>
 6  #include <test/fuzz/FuzzedDataProvider.h>
 7  #include <test/fuzz/fuzz.h>
 8  #include <test/fuzz/util.h>
 9  #include <uint256.h>
10  
11  #include <cassert>
12  #include <cstdint>
13  #include <optional>
14  #include <string>
15  #include <vector>
16  
17  FUZZ_TARGET(block_header)
18  {
19      FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());
20      const std::optional<CBlockHeader> block_header = ConsumeDeserializable<CBlockHeader>(fuzzed_data_provider);
21      if (!block_header) {
22          return;
23      }
24      {
25          const uint256 hash = block_header->GetHash();
26          constexpr uint256 u256_max{"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"};
27          assert(hash != u256_max);
28          assert(block_header->GetBlockTime() == block_header->nTime);
29          assert(block_header->IsNull() == (block_header->nBits == 0));
30      }
31      {
32          CBlockHeader mut_block_header = *block_header;
33          mut_block_header.SetNull();
34          assert(mut_block_header.IsNull());
35          CBlock block{*block_header};
36          assert(block.GetHash() == block_header->GetHash());
37          (void)block.ToString();
38          block.SetNull();
39          assert(block.GetHash() == mut_block_header.GetHash());
40      }
41      {
42          std::optional<CBlockLocator> block_locator = ConsumeDeserializable<CBlockLocator>(fuzzed_data_provider);
43          if (block_locator) {
44              (void)block_locator->IsNull();
45              block_locator->SetNull();
46              assert(block_locator->IsNull());
47          }
48      }
49  }