tx_check.cpp raw

   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  #include <consensus/tx_check.h>
   6  
   7  #include <consensus/amount.h>
   8  #include <primitives/transaction.h>
   9  #include <consensus/validation.h>
  10  
  11  bool CheckTransaction(const CTransaction& tx, TxValidationState& state)
  12  {
  13      // Basic checks that don't depend on any context
  14      if (tx.vin.empty())
  15          return state.Invalid(TxValidationResult::TX_CONSENSUS, "bad-txns-vin-empty");
  16      if (tx.vout.empty())
  17          return state.Invalid(TxValidationResult::TX_CONSENSUS, "bad-txns-vout-empty");
  18      // Size limits (this doesn't take the witness into account, as that hasn't been checked for malleability)
  19      if (::GetSerializeSize(TX_NO_WITNESS(tx)) * WITNESS_SCALE_FACTOR > MAX_BLOCK_WEIGHT) {
  20          return state.Invalid(TxValidationResult::TX_CONSENSUS, "bad-txns-oversize");
  21      }
  22  
  23      // Check for negative or overflow output values (see CVE-2010-5139)
  24      CAmount nValueOut = 0;
  25      for (const auto& txout : tx.vout)
  26      {
  27          if (txout.nValue < 0)
  28              return state.Invalid(TxValidationResult::TX_CONSENSUS, "bad-txns-vout-negative");
  29          if (txout.nValue > MAX_MONEY)
  30              return state.Invalid(TxValidationResult::TX_CONSENSUS, "bad-txns-vout-toolarge");
  31          nValueOut += txout.nValue;
  32          if (!MoneyRange(nValueOut))
  33              return state.Invalid(TxValidationResult::TX_CONSENSUS, "bad-txns-txouttotal-toolarge");
  34      }
  35  
  36      // Check for duplicate inputs (see CVE-2018-17144)
  37      // While Consensus::CheckTxInputs does check if all inputs of a tx are available, and UpdateCoins marks all inputs
  38      // of a tx as spent, it does not check if the tx has duplicate inputs.
  39      // Failure to run this check will result in either a crash or an inflation bug, depending on the implementation of
  40      // the underlying coins database.
  41      std::set<COutPoint> vInOutPoints;
  42      for (const auto& txin : tx.vin) {
  43          if (!vInOutPoints.insert(txin.prevout).second)
  44              return state.Invalid(TxValidationResult::TX_CONSENSUS, "bad-txns-inputs-duplicate");
  45      }
  46  
  47      if (tx.IsCoinBase())
  48      {
  49          if (tx.vin[0].scriptSig.size() < 2 || tx.vin[0].scriptSig.size() > 100)
  50              return state.Invalid(TxValidationResult::TX_CONSENSUS, "bad-cb-length");
  51      }
  52      else
  53      {
  54          for (const auto& txin : tx.vin)
  55              if (txin.prevout.IsNull())
  56                  return state.Invalid(TxValidationResult::TX_CONSENSUS, "bad-txns-prevout-null");
  57      }
  58  
  59      return true;
  60  }
  61