bech32.cpp raw

   1  // Copyright (c) 2019-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 <bech32.h>
   6  #include <test/fuzz/fuzz.h>
   7  #include <test/fuzz/FuzzedDataProvider.h>
   8  #include <util/strencodings.h>
   9  
  10  #include <cassert>
  11  #include <cstdint>
  12  #include <string>
  13  #include <vector>
  14  
  15  FUZZ_TARGET(bech32_random_decode)
  16  {
  17      auto limit = bech32::CharLimit::BECH32;
  18      FuzzedDataProvider fdp(buffer.data(), buffer.size());
  19      auto random_string = fdp.ConsumeRandomLengthString(limit + 1);
  20      auto decoded = bech32::Decode(random_string, limit);
  21  
  22      if (decoded.hrp.empty()) {
  23          assert(decoded.encoding == bech32::Encoding::INVALID);
  24          assert(decoded.data.empty());
  25      } else {
  26          assert(decoded.encoding != bech32::Encoding::INVALID);
  27          auto reencoded = bech32::Encode(decoded.encoding, decoded.hrp, decoded.data);
  28          assert(CaseInsensitiveEqual(random_string, reencoded));
  29      }
  30  }
  31  
  32  // https://github.com/bitcoin/bips/blob/master/bip-0173.mediawiki and https://github.com/bitcoin/bips/blob/master/bip-0350.mediawiki
  33  std::string GenerateRandomHRP(FuzzedDataProvider& fdp)
  34  {
  35      std::string hrp;
  36      size_t length = fdp.ConsumeIntegralInRange<size_t>(1, 83);
  37      for (size_t i = 0; i < length; ++i) {
  38          // Generate lowercase ASCII characters in ([33-126] - ['A'-'Z']) range
  39          char c = fdp.ConsumeBool()
  40                   ? fdp.ConsumeIntegralInRange<char>(33, 'A' - 1)
  41                   : fdp.ConsumeIntegralInRange<char>('Z' + 1, 126);
  42          hrp += c;
  43      }
  44      return hrp;
  45  }
  46  
  47  FUZZ_TARGET(bech32_roundtrip)
  48  {
  49      FuzzedDataProvider fdp(buffer.data(), buffer.size());
  50      auto hrp = GenerateRandomHRP(fdp);
  51  
  52      auto input_chars = fdp.ConsumeBytes<unsigned char>(fdp.ConsumeIntegralInRange<size_t>(0, 82));
  53      std::vector<uint8_t> converted_input;
  54      ConvertBits<8, 5, true>([&](auto c) { converted_input.push_back(c); }, input_chars.begin(), input_chars.end());
  55  
  56      auto size = converted_input.size() + hrp.length() + std::string({bech32::SEPARATOR}).size() + bech32::CHECKSUM_SIZE;
  57      if (size <= bech32::CharLimit::BECH32) {
  58          for (auto encoding: {bech32::Encoding::BECH32, bech32::Encoding::BECH32M}) {
  59              auto encoded = bech32::Encode(encoding, hrp, converted_input);
  60              assert(!encoded.empty());
  61  
  62              const auto decoded = bech32::Decode(encoded);
  63              assert(decoded.encoding == encoding);
  64              assert(decoded.hrp == hrp);
  65              assert(decoded.data == converted_input);
  66          }
  67      }
  68  }
  69