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