Line data    Source code

       1             : // Copyright (c) 2009-2010 Satoshi Nakamoto
       2             : // Copyright (c) 2009-2018 The Bitcoin developers
       3             : // Copyright (c) 2018-2021 The PIVX Core developers
       4             : // Distributed under the MIT software license, see the accompanying
       5             : // file COPYING or http://www.opensource.org/licenses/mit-license.php.
       6             : 
       7             : #ifndef PIVX_SCRIPT_INTERPRETER_H
       8             : #define PIVX_SCRIPT_INTERPRETER_H
       9             : 
      10             : #include "primitives/transaction.h"
      11             : #include "script_error.h"
      12             : #include "uint256.h"
      13             : 
      14             : #include <vector>
      15             : #include <stdint.h>
      16             : #include <string>
      17             : 
      18             : /** Special case nIn for signing Sapling txs. */
      19             : const unsigned int NOT_AN_INPUT = UINT_MAX;
      20             : 
      21             : /** Signature hash types/flags */
      22             : enum
      23             : {
      24             :     SIGHASH_ALL = 1,
      25             :     SIGHASH_NONE = 2,
      26             :     SIGHASH_SINGLE = 3,
      27             :     SIGHASH_ANYONECANPAY = 0x80,
      28             : };
      29             : 
      30             : /** Script verification flags */
      31             : enum
      32             : {
      33             :     SCRIPT_VERIFY_NONE      = 0,
      34             : 
      35             :     // Evaluate P2SH subscripts (softfork safe, BIP16).
      36             :     SCRIPT_VERIFY_P2SH      = (1U << 0),
      37             : 
      38             :     // Passing a non-strict-DER signature or one with undefined hashtype to a checksig operation causes script failure.
      39             :     // Evaluating a pubkey that is not (0x04 + 64 bytes) or (0x02 or 0x03 + 32 bytes) by checksig causes script failure.
      40             :     // (softfork safe, but not used or intended as a consensus rule).
      41             :     SCRIPT_VERIFY_STRICTENC = (1U << 1),
      42             : 
      43             :     // Passing a non-strict-DER signature to a checksig operation causes script failure (softfork safe, BIP62 rule 1)
      44             :     SCRIPT_VERIFY_DERSIG    = (1U << 2),
      45             : 
      46             :     // Passing a non-strict-DER signature or one with S > order/2 to a checksig operation causes script failure
      47             :     // (softfork safe, BIP62 rule 5).
      48             :     SCRIPT_VERIFY_LOW_S     = (1U << 3),
      49             : 
      50             :     // verify dummy stack item consumed by CHECKMULTISIG is of zero-length (softfork safe, BIP62 rule 7).
      51             :     SCRIPT_VERIFY_NULLDUMMY = (1U << 4),
      52             : 
      53             :     // Using a non-push operator in the scriptSig causes script failure (softfork safe, BIP62 rule 2).
      54             :     SCRIPT_VERIFY_SIGPUSHONLY = (1U << 5),
      55             : 
      56             :     // Require minimal encodings for all push operations (OP_0... OP_16, OP_1NEGATE where possible, direct
      57             :     // pushes up to 75 bytes, OP_PUSHDATA up to 255 bytes, OP_PUSHDATA2 for anything larger). Evaluating
      58             :     // any other push causes the script to fail (BIP62 rule 3).
      59             :     // In addition, whenever a stack element is interpreted as a number, it must be of minimal length (BIP62 rule 4).
      60             :     // (softfork safe)
      61             :     SCRIPT_VERIFY_MINIMALDATA = (1U << 6),
      62             : 
      63             :     // Discourage use of NOPs reserved for upgrades (NOP1-10)
      64             :     //
      65             :     // Provided so that nodes can avoid accepting or mining transactions
      66             :     // containing executed NOP's whose meaning may change after a soft-fork,
      67             :     // thus rendering the script invalid; with this flag set executing
      68             :     // discouraged NOPs fails the script. This verification flag will never be
      69             :     // a mandatory flag applied to scripts in a block. NOPs that are not
      70             :     // executed, e.g.  within an unexecuted IF ENDIF block, are *not* rejected.
      71             :     SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS  = (1U << 7),
      72             : 
      73             :     // Require that only a single stack element remains after evaluation. This changes the success criterion from
      74             :     // "At least one stack element must remain, and when interpreted as a boolean, it must be true" to
      75             :     // "Exactly one stack element must remain, and when interpreted as a boolean, it must be true".
      76             :     // (softfork safe, BIP62 rule 6)
      77             :     // Note: CLEANSTACK should never be used without P2SH.
      78             :     SCRIPT_VERIFY_CLEANSTACK = (1U << 8),
      79             : 
      80             :     // Verify CHECKLOCKTIMEVERIFY
      81             :     //
      82             :     // See BIP65 for details.
      83             :     SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY = (1U << 9),
      84             : 
      85             :     // Verify OP_EXCHANGEADDR.
      86             :     // Treat as UNKNOWN before 5.6 activation
      87             :     SCRIPT_VERIFY_EXCHANGEADDR = (1U << 10),
      88             : };
      89             : 
      90             : bool CheckSignatureEncoding(const std::vector<unsigned char> &vchSig, unsigned int flags, ScriptError* serror);
      91             : 
      92             : struct PrecomputedTransactionData
      93             : {
      94             :     uint256 hashPrevouts, hashSequence, hashOutputs, hashShieldedSpends, hashShieldedOutputs;
      95             : 
      96             :     explicit PrecomputedTransactionData(const CTransaction& tx);
      97             : };
      98             : 
      99             : uint256 SignatureHash(const CScript &scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType, const CAmount& amount, SigVersion sigversion, const PrecomputedTransactionData* cache = nullptr);
     100             : 
     101     2361047 : class BaseSignatureChecker
     102             : {
     103             : public:
     104           0 :     virtual bool CheckSig(const std::vector<unsigned char>& scriptSig, const std::vector<unsigned char>& vchPubKey, const CScript& scriptCode, SigVersion sigversion) const
     105             :     {
     106           0 :         return false;
     107             :     }
     108             : 
     109           0 :     virtual bool CheckLockTime(const CScriptNum& nLockTime) const
     110             :     {
     111           0 :          return false;
     112             :     }
     113             : 
     114          74 :     virtual bool CheckColdStake(bool fAllowLastOutputFree, const CScript& prevoutScript, std::vector<valtype>& stack, unsigned int flags, ScriptError* error) const
     115             :     {
     116          74 :          return false;
     117             :     }
     118             : 
     119     2565864 :     virtual ~BaseSignatureChecker() {}
     120             : };
     121             : 
     122     2081560 : class TransactionSignatureChecker : public BaseSignatureChecker
     123             : {
     124             : private:
     125             :     const CTransaction* txTo;
     126             :     unsigned int nIn;
     127             :     const CAmount amount;
     128             :     const PrecomputedTransactionData* precomTxData;
     129             : 
     130             : protected:
     131             :     virtual bool VerifySignature(const std::vector<unsigned char>& vchSig, const CPubKey& vchPubKey, const uint256& sighash) const;
     132             : 
     133             : public:
     134      625073 :     TransactionSignatureChecker(const CTransaction* txToIn, unsigned int nInIn, const CAmount& amountIn) : txTo(txToIn), nIn(nInIn), amount(amountIn), precomTxData(nullptr) {}
     135     1456455 :     TransactionSignatureChecker(const CTransaction* txToIn, unsigned int nInIn, const CAmount& amountIn, const PrecomputedTransactionData& cachedHashesIn) : txTo(txToIn), nIn(nInIn), amount(amountIn), precomTxData(&cachedHashesIn) {}
     136             : 
     137             :     bool CheckSig(const std::vector<unsigned char>& scriptSig, const std::vector<unsigned char>& vchPubKey, const CScript& scriptCode, SigVersion sigversion) const override ;
     138             :     bool CheckLockTime(const CScriptNum& nLockTime) const override;
     139             :     bool CheckColdStake(bool fAllowLastOutputFree, const CScript& prevoutScript, std::vector<valtype>& stack, unsigned int flags, ScriptError* serror) const override;
     140             : };
     141             : 
     142        1238 : class MutableTransactionSignatureChecker : public TransactionSignatureChecker
     143             : {
     144             : private:
     145             :     const CTransaction txTo;
     146             : 
     147             : public:
     148         112 :     MutableTransactionSignatureChecker(const CMutableTransaction* txToIn, unsigned int nInIn, const CAmount& amount) : TransactionSignatureChecker(&txTo, nInIn, amount), txTo(*txToIn) {}
     149             : };
     150             : 
     151             : bool EvalScript(std::vector<std::vector<unsigned char> >& stack, const CScript& script, unsigned int flags, const BaseSignatureChecker& checker, SigVersion sigversion, ScriptError* error = nullptr);
     152             : bool VerifyScript(const CScript& scriptSig, const CScript& scriptPubKey, unsigned int flags, const BaseSignatureChecker& checker, SigVersion sigversion, ScriptError* serror = nullptr);
     153             : 
     154             : #endif // PIVX_SCRIPT_INTERPRETER_H