text: // Copyright (c) 2020 The Askalcoin Core developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include <chainparams.h>
  #include <chainparamsbase.h>
  #include <key.h>
  #include <pubkey.h>
  #include <script/sigcache.h>
  #include <test/fuzz/FuzzedDataProvider.h>
  #include <test/fuzz/fuzz.h>
  #include <test/fuzz/util.h>
  
  #include <cstdint>
  #include <optional>
  #include <string>
  #include <vector>
  
  void initialize_script_sigcache()
  {
      static const ECCVerifyHandle ecc_verify_handle;
      ECC_Start();
      SelectParams(CBaseChainParams::REGTEST);
      InitSignatureCache();
  }
  
  FUZZ_TARGET_INIT(script_sigcache, initialize_script_sigcache)
  {
      FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());
  
      const std::optional<CMutableTransaction> mutable_transaction = ConsumeDeserializable<CMutableTransaction>(fuzzed_data_provider);
      const CTransaction tx{mutable_transaction ? *mutable_transaction : CMutableTransaction{}};
      const unsigned int n_in = fuzzed_data_provider.ConsumeIntegral<unsigned int>();
      const CAmount amount = ConsumeMoney(fuzzed_data_provider);
      const bool store = fuzzed_data_provider.ConsumeBool();
      PrecomputedTransactionData tx_data;
      CachingTransactionSignatureChecker caching_transaction_signature_checker{mutable_transaction ? &tx : nullptr, n_in, amount, store, tx_data};
      if (fuzzed_data_provider.ConsumeBool()) {
          const auto random_bytes = fuzzed_data_provider.ConsumeBytes<unsigned char>(64);
          const XOnlyPubKey pub_key(ConsumeUInt256(fuzzed_data_provider));
          if (random_bytes.size() == 64) {
              (void)caching_transaction_signature_checker.VerifySchnorrSignature(random_bytes, pub_key, ConsumeUInt256(fuzzed_data_provider));
          }
      } else {
          const auto random_bytes = ConsumeRandomLengthByteVector(fuzzed_data_provider);
          const auto pub_key = ConsumeDeserializable<CPubKey>(fuzzed_data_provider);
          if (pub_key) {
              if (!random_bytes.empty()) {
                  (void)caching_transaction_signature_checker.VerifyECDSASignature(random_bytes, *pub_key, ConsumeUInt256(fuzzed_data_provider));
              }
          }
      }
  }
  