bool AreInputsStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs)
{
if (tx.IsCoinBase())
return true; // Coinbases don't use vin normally
for (unsigned int i = 0; i < tx.vin.size(); i++)
{
const CTxOut& prev = mapInputs.AccessCoin(tx.vin[i].prevout).out;
std::vector<std::vector<unsigned char> > vSolutions;
txnouttype whichType;
// get the scriptPubKey corresponding to this input:
const CScript& prevScript = prev.scriptPubKey;
if (!Solver(prevScript, whichType, vSolutions))
return false;
if (whichType == TX_SCRIPTHASH)
{
std::vector<std::vector<unsigned char> > stack;
// convert the scriptSig into a stack, so we can inspect the redeemScript
if (!EvalScript(stack, tx.vin[i].scriptSig, SCRIPT_VERIFY_NONE, BaseSignatureChecker(), SIGVERSION_BASE))
return false;
if (stack.empty())
return false;
CScript subscript(stack.back().begin(), stack.back().end());
if (subscript.GetSigOpCount(true) > MAX_P2SH_SIGOPS) {
return false;
}
}
}
return true;
}
void ReplaceRedeemScript(CScript& script, const CScript& redeemScript)
{
std::vector<valtype> stack;
EvalScript(stack, script, SCRIPT_VERIFY_STRICTENC, BaseSignatureChecker(), SIGVERSION_BASE);
assert(stack.size() > 0);
stack.back() = std::vector<unsigned char>(redeemScript.begin(), redeemScript.end());
script = PushAll(stack);
}
bool AreInputsStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs)
{
if (tx.IsCoinBase())
return true; // Coinbases don't use vin normally
for (unsigned int i = 0; i < tx.vin.size(); i++)
{
const CTxOut& prev = mapInputs.GetOutputFor(tx.vin[i]);
std::vector<std::vector<unsigned char> > vSolutions;
txnouttype whichType;
// get the scriptPubKey corresponding to this input:
const CScript& prevScript = prev.scriptPubKey;
if (!Solver(prevScript, whichType, vSolutions))
return false;
int nArgsExpected = ScriptSigArgsExpected(whichType, vSolutions);
if (nArgsExpected < 0)
return false;
// Transactions with extra stuff in their scriptSigs are
// non-standard. Note that this EvalScript() call will
// be quick, because if there are any operations
// beside "push data" in the scriptSig
// IsStandardTx() will have already returned false
// and this method isn't called.
std::vector<std::vector<unsigned char> > stack;
if (!EvalScript(stack, tx.vin[i].scriptSig, SCRIPT_VERIFY_NONE, BaseSignatureChecker()))
return false;
if (whichType == TX_SCRIPTHASH)
{
if (stack.empty())
return false;
CScript subscript(stack.back().begin(), stack.back().end());
std::vector<std::vector<unsigned char> > vSolutions2;
txnouttype whichType2;
if (Solver(subscript, whichType2, vSolutions2))
{
int tmpExpected = ScriptSigArgsExpected(whichType2, vSolutions2);
if (tmpExpected < 0)
return false;
nArgsExpected += tmpExpected;
}
else
{
// Any other Script with less than 15 sigops OK:
unsigned int sigops = subscript.GetSigOpCount(true);
// ... extra data left on the stack after execution is OK, too:
return (sigops <= MAX_P2SH_SIGOPS);
}
}
if (stack.size() != (unsigned int)nArgsExpected)
return false;
}
return true;
}
bool IsWitnessStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs)
{
if (tx.IsCoinBase())
return true; // Coinbases are skipped
for (unsigned int i = 0; i < tx.vin.size(); i++)
{
// We don't care if witness for this input is empty, since it must not be bloated.
// If the script is invalid without witness, it would be caught sooner or later during validation.
if (tx.vin[i].scriptWitness.IsNull())
continue;
const CTxOut &prev = mapInputs.AccessCoin(tx.vin[i].prevout).out;
// get the scriptPubKey corresponding to this input:
CScript prevScript = prev.scriptPubKey;
if (prevScript.IsPayToScriptHash()) {
std::vector <std::vector<unsigned char> > stack;
// If the scriptPubKey is P2SH, we try to extract the redeemScript casually by converting the scriptSig
// into a stack. We do not check IsPushOnly nor compare the hash as these will be done later anyway.
// If the check fails at this stage, we know that this txid must be a bad one.
if (!EvalScript(stack, tx.vin[i].scriptSig, SCRIPT_VERIFY_NONE, BaseSignatureChecker(), SIGVERSION_BASE))
return false;
if (stack.empty())
return false;
prevScript = CScript(stack.back().begin(), stack.back().end());
}
int witnessversion = 0;
std::vector<unsigned char> witnessprogram;
// Non-witness program must not be associated with any witness
if (!prevScript.IsWitnessProgram(witnessversion, witnessprogram))
return false;
// Check P2WSH standard limits
if (witnessversion == 0 && witnessprogram.size() == 32) {
if (tx.vin[i].scriptWitness.stack.back().size() > MAX_STANDARD_P2WSH_SCRIPT_SIZE)
return false;
size_t sizeWitnessStack = tx.vin[i].scriptWitness.stack.size() - 1;
if (sizeWitnessStack > MAX_STANDARD_P2WSH_STACK_ITEMS)
return false;
for (unsigned int j = 0; j < sizeWitnessStack; j++) {
if (tx.vin[i].scriptWitness.stack[j].size() > MAX_STANDARD_P2WSH_STACK_ITEM_SIZE)
return false;
}
}
}
return true;
}
