1  // Copyright (c) 2019-2021 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/util/str.h>
 8  #include <util/strencodings.h>
 9  
10  #include <cassert>
11  #include <cstdint>
12  #include <string>
13  #include <utility>
14  #include <vector>
15  
16  FUZZ_TARGET(bech32)
17  {
18      const std::string random_string(buffer.begin(), buffer.end());
19      const auto r1 = bech32::Decode(random_string);
20      if (r1.hrp.empty()) {
21          assert(r1.encoding == bech32::Encoding::INVALID);
22          assert(r1.data.empty());
23      } else {
24          assert(r1.encoding != bech32::Encoding::INVALID);
25          const std::string reencoded = bech32::Encode(r1.encoding, r1.hrp, r1.data);
26          assert(CaseInsensitiveEqual(random_string, reencoded));
27      }
28  
29      std::vector<unsigned char> input;
30      ConvertBits<8, 5, true>([&](unsigned char c) { input.push_back(c); }, buffer.begin(), buffer.end());
31  
32      if (input.size() + 3 + 6 <= 90) {
33          // If it's possible to encode input in Bech32(m) without exceeding the 90-character limit:
34          for (auto encoding : {bech32::Encoding::BECH32, bech32::Encoding::BECH32M}) {
35              const std::string encoded = bech32::Encode(encoding, "bc", input);
36              assert(!encoded.empty());
37              const auto r2 = bech32::Decode(encoded);
38              assert(r2.encoding == encoding);
39              assert(r2.hrp == "bc");
40              assert(r2.data == input);
41          }
42      }
43  }