wownero/src/cryptonote_core/tx_verification_utils.h

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#pragma once

#include "common/data_cache.h"
#include "cryptonote_basic/cryptonote_basic.h"
#include "cryptonote_basic/verification_context.h"

namespace cryptonote
{

/**
 * @brief Get the maximum transaction weight for a given hardfork
 *
 * @param hf_version hard fork version
 * @return the maximum unconditional transaction weight
 */
uint64_t get_transaction_weight_limit(uint8_t hf_version);

// Modifying this value should not affect consensus. You can adjust it for performance needs
static constexpr const size_t RCT_VER_CACHE_SIZE = 8192;

using rct_ver_cache_t = ::tools::data_cache<::crypto::hash, RCT_VER_CACHE_SIZE>;

/**
 * @brief Cached version of rct::verRctNonSemanticsSimple
 *
 * This function will not affect how the transaction is serialized and it will never modify the
 * transaction prefix.
 *
 * The reference to tx is mutable since the transaction's ring signatures may be expanded by
 * Blockchain::expand_transaction_2. However, on cache hits, the transaction will not be
 * expanded. This means that the caller does not need to call expand_transaction_2 on this
 * transaction before passing it; the transaction will not successfully verify with "old" RCT data
 * if the transaction has been otherwise modified since the last verification.
 *
 * But, if cryptonote::get_transaction_hash(tx) returns a "stale" hash, this function is not
 * guaranteed to work. So make sure that the cryptonote::transaction passed has not had
 * modifications to it since the last time its hash was fetched without properly invalidating the
 * hashes.
 *
 * rct_type_to_cache can be any RCT version value as long as rct::verRctNonSemanticsSimple works for
 * this RCT version, but for most applications, it doesn't make sense to not make this version
 * the "current" RCT version (i.e. the version that transactions in the mempool are).
 *
 * @param tx transaction which contains RCT signature to verify
 * @param mix_ring mixring referenced by this tx. THIS DATA MUST BE PREVIOUSLY VALIDATED
 * @param cache saves tx+mixring hashes used to cache calls
 * @param rct_type_to_cache Only RCT sigs with version (e.g. RCTTypeBulletproofPlus) will be cached
 * @return true when verRctNonSemanticsSimple() w/ expanded tx.rct_signatures would return true
 * @return false when verRctNonSemanticsSimple() w/ expanded tx.rct_signatures would return false
 */
bool ver_rct_non_semantics_simple_cached
(
    transaction& tx,
    const rct::ctkeyM& mix_ring,
    rct_ver_cache_t& cache,
    std::uint8_t rct_type_to_cache
);

/**
 * @brief Verify the semantics of a group of RingCT signatures as a batch (if applicable)
 *
 * Coinbase txs or other transaction with a RingCT type of RCTTypeNull will fail to verify.
 *
 * @param rvv list of signatures to verify
 * @return true if all signatures verified semantics successfully, false otherwise
 */
bool ver_mixed_rct_semantics(std::vector<const rct::rctSig*> rvv);

/**
 * @brief Used to provide transaction info that skips the mempool to block handling code 
 */
struct pool_supplement
{
    // Map of supplemental tx info that we might need to validate a block
    // Maps TXID -> transaction and blob
    std::unordered_map<crypto::hash, std::pair<transaction, blobdata>> txs_by_txid;
    // If non-zero, then consider all the txs' non-input consensus (NIC) rules verified for this
    // hard fork. User: If you add an unverified transaction to txs_by_txid, set this field to zero!
    mutable std::uint8_t nic_verified_hf_version = 0;
};

/**
 * @brief Verify every non-input consensus rule for a group of non-coinbase transactions
 *
 * List of checks that we do for each transaction:
 *     1. Check tx blob size < get_max_tx_size()
 *     2. Check tx version != 0
 *     3. Check tx version is less than maximum for given hard fork version
 *     4. Check tx weight < get_transaction_weight_limit()
 *     5. Passes core::check_tx_semantic()
 *     6. Passes Blockchain::check_tx_outputs()
 *     7. Passes ver_mixed_rct_semantics() [Uses batch RingCT verification when applicable]
 *
 * For pool_supplement input:
 * We assume the structure of the pool supplement is already correct: for each value entry, the
 * cryptonote::transaction matches its corresponding blobdata and the TXID map key is correctly
 * calculated for that transaction. We use the .nic_verified_hf_version field to skip verification
 * for the pool supplement if hf_version matches, and we cache that version on success.
 *
 * @param tx single transaction to verify
 * @param pool_supplement pool supplement to verify
 * @param tvc relevant flags will be set for if/why verification failed
 * @param hf_version Hard fork version to run rules against
 * @return true if all relevant transactions verify, false otherwise
 */
bool ver_non_input_consensus(const transaction& tx, tx_verification_context& tvc,
    std::uint8_t hf_version);

bool ver_non_input_consensus(const pool_supplement& ps, tx_verification_context& tvc,
    std::uint8_t hf_version);

} // namespace cryptonote