#include <util/check.h>

FUZZ_TARGET(sighash_cache)

{

FuzzedDataProvider provider(buffer.data(), buffer.size());

// Get inputs to the sighash function that won't change across types.

const auto scriptcode{ConsumeScript(provider)};

const auto tx{ConsumeTransaction(provider, std::nullopt)};

if (tx.vin.empty()) return;

const auto in_index{provider.ConsumeIntegralInRange<uint32_t>(0, tx.vin.size() - 1)};

const auto amount{ConsumeMoney(provider)};

const auto sigversion{(SigVersion)provider.ConsumeIntegralInRange(0, 1)};

// Check the sighash function will give the same result for 100 fuzzer-generated hash types whether or not a cache is

// provided. The cache is conserved across types to exercise cache hits.

SigHashCache sighash_cache{};

for (int i{0}; i < 100; ++i) {

const auto hash_type{((i & 2) == 0) ? provider.ConsumeIntegral<int8_t>() : provider.ConsumeIntegral<int32_t>()};

const auto nocache_res{SignatureHash(scriptcode, tx, in_index, hash_type, amount, sigversion)};

const auto cache_res{SignatureHash(scriptcode, tx, in_index, hash_type, amount, sigversion, nullptr, &sighash_cache)};

Assert(nocache_res == cache_res);

}

}