1// Copyright (c) 2017-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#ifndef BITCOIN_CONSENSUS_TX_VERIFY_H
6#define BITCOIN_CONSENSUS_TX_VERIFY_H
7
8#include <consensus/amount.h>
9#include <script/verify_flags.h>
10
11#include <cstdint>
12#include <utility>
13#include <vector>
14
15class CBlockIndex;
16class CCoinsViewCache;
17class CTransaction;
18class TxValidationState;
19
20/** Transaction validation functions */
21
22namespace Consensus {
23/**
24 * Check whether all inputs of this transaction are valid (no double spends and amounts)
25 * This does not modify the UTXO set. This does not check scripts and sigs.
26 * @param[out] txfee Set to the transaction fee if successful.
27 * Preconditions: tx.IsCoinBase() is false.
28 */
29[[nodiscard]] bool CheckTxInputs(const CTransaction& tx, TxValidationState& state, const CCoinsViewCache& inputs, int nSpendHeight, CAmount& txfee);
30} // namespace Consensus
31
32/** Auxiliary functions for transaction validation (ideally should not be exposed) */
33
34/**
35 * Count ECDSA signature operations the old-fashioned (pre-0.6) way
36 * @return number of sigops this transaction's outputs will produce when spent
37 * @see CTransaction::FetchInputs
38 */
39unsigned int GetLegacySigOpCount(const CTransaction& tx);
40
41/**
42 * Count ECDSA signature operations in pay-to-script-hash inputs.
43 *
44 * @param[in] mapInputs Map of previous transactions that have outputs we're spending
45 * @return maximum number of sigops required to validate this transaction's inputs
46 * @see CTransaction::FetchInputs
47 */
48unsigned int GetP2SHSigOpCount(const CTransaction& tx, const CCoinsViewCache& mapInputs);
49
50/**
51 * Compute total signature operation cost of a transaction.
52 * @param[in] tx     Transaction for which we are computing the cost
53 * @param[in] inputs Map of previous transactions that have outputs we're spending
54 * @param[in] flags Script verification flags
55 * @return Total signature operation cost of tx
56 */
57int64_t GetTransactionSigOpCost(const CTransaction& tx, const CCoinsViewCache& inputs, script_verify_flags flags);
58
59/**
60 * Check if transaction is final and can be included in a block with the
61 * specified height and time. Consensus critical.
62 */
63bool IsFinalTx(const CTransaction &tx, int nBlockHeight, int64_t nBlockTime);
64
65/**
66 * Calculates the block height and previous block's median time past at
67 * which the transaction will be considered final in the context of BIP 68.
68 * For each input that is not sequence locked, the corresponding entries in
69 * prevHeights are set to 0 as they do not affect the calculation.
70 */
71std::pair<int, int64_t> CalculateSequenceLocks(const CTransaction &tx, int flags, std::vector<int>& prevHeights, const CBlockIndex& block);
72
73bool EvaluateSequenceLocks(const CBlockIndex& block, std::pair<int, int64_t> lockPair);
74/**
75 * Check if transaction is final per BIP 68 sequence numbers and can be included in a block.
76 * Consensus critical. Takes as input a list of heights at which tx's inputs (in order) confirmed.
77 */
78bool SequenceLocks(const CTransaction &tx, int flags, std::vector<int>& prevHeights, const CBlockIndex& block);
79
80#endif // BITCOIN_CONSENSUS_TX_VERIFY_H
81