Differential D3474 Diff 10497 src/script/interpreter.cpp

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src/script/interpreter.cpp

// Copyright (c) 2009-2010 Satoshi Nakamoto		// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2016 The Bitcoin Core developers		// Copyright (c) 2009-2016 The Bitcoin Core developers
// Copyright (c) 2017-2018 The Bitcoin developers		// Copyright (c) 2017-2018 The Bitcoin developers
// Distributed under the MIT software license, see the accompanying		// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.		// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include <script/interpreter.h>		#include <script/interpreter.h>

#include <crypto/ripemd160.h>		#include <crypto/ripemd160.h>
#include <crypto/sha1.h>		#include <crypto/sha1.h>
#include <crypto/sha256.h>		#include <crypto/sha256.h>
#include <primitives/transaction.h>		#include <primitives/transaction.h>
#include <pubkey.h>		#include <pubkey.h>
		#include <script/bitfield.h>
#include <script/script.h>		#include <script/script.h>
#include <script/script_flags.h>		#include <script/script_flags.h>
#include <script/sigencoding.h>		#include <script/sigencoding.h>
#include <uint256.h>		#include <uint256.h>
		#include <util/bitmanip.h>

bool CastToBool(const valtype &vch) {		bool CastToBool(const valtype &vch) {
for (size_t i = 0; i < vch.size(); i++) {		for (size_t i = 0; i < vch.size(); i++) {
if (vch[i] != 0) {		if (vch[i] != 0) {
// Can be negative zero		// Can be negative zero
if (i == vch.size() - 1 && vch[i] == 0x80) {		if (i == vch.size() - 1 && vch[i] == 0x80) {
return false;		return false;
}		}
▲ Show 20 Lines • Show All 979 Lines • ▼ Show 20 Lines	try {

// stack depth of the dummy element		// stack depth of the dummy element
const size_t idxDummy = idxTopSig + nSigsCount;		const size_t idxDummy = idxTopSig + nSigsCount;
if (stack.size() < idxDummy) {		if (stack.size() < idxDummy) {
return set_error(		return set_error(
serror, ScriptError::INVALID_STACK_OPERATION);		serror, ScriptError::INVALID_STACK_OPERATION);
}		}

		// Subset of script starting at the most recent
		// codeseparator
		CScript scriptCode(pbegincodehash, pend);

		// Assuming success is usually a bad idea, but the
		// schnorr path can only succeed.
		bool fSuccess = true;

		if ((flags & SCRIPT_ENABLE_SCHNORR_MULTISIG) &&
		stacktop(-idxDummy).size() != 0) {
		// NEW MULTISIG (SCHNORR / NULL)
		markblundebergUnsubmitted Not Done Inline Actions Ah, I forgot to change this comment - should just read `NEW MULTISIG (SCHNORR)` markblundeberg: Ah, I forgot to change this comment - should just read `NEW MULTISIG (SCHNORR)`
		static_assert(MAX_PUBKEYS_PER_MULTISIG <= 32);
		uint32_t checkBits = 0;

		// Dummy element is to be interpreted as a bitfield
		// that represent which pubkeys should be checked.
		valtype &vchDummy = stacktop(-idxDummy);
		if (!DecodeBitfield(vchDummy, nKeysCount, checkBits,
		serror)) {
		// serror is set
		return false;
		}

		// The bitfield doesn't set the right number of
		// signatures.
		if (countBits(checkBits) != uint32_t(nSigsCount)) {
		return set_error(
		serror, ScriptError::INVALID_BIT_COUNT);
		}

		const size_t idxBottomKey =
		idxTopKey + nKeysCount - 1;
		const size_t idxBottomSig =
		idxTopSig + nSigsCount - 1;

		int iKey = 0;
		for (int iSig = 0; iSig < nSigsCount;
		iSig++, iKey++) {
		if ((checkBits >> iKey) == 0) {
		// This is a sanity check and should be
		markblundebergUnsubmitted Not Done Inline Actions For such sanity checks, isn't it better to have an assert than to make a silent consensus judgement (script invalid & transaction invalid & block invalid)? If these conditions are violated then something is seriously wrong ... and there are already several asserts like this in interpreter.cpp. markblundeberg: For such sanity checks, isn't it better to have an assert than to make a silent consensus…
		// unrecheable.
		return set_error(
		serror, ScriptError::INVALID_BIT_RANGE);
		}

		// Find the next suitable key.
		while (((checkBits >> iKey) & 0x01) == 0) {
		iKey++;
		}

		if (iKey >= nKeysCount) {
		// This is a sanity check and should be
		// unrecheable.
		markblundebergUnsubmitted Not Done Inline Actions ditto markblundeberg: ditto
		return set_error(serror,
		ScriptError::PUBKEY_COUNT);
		}

		// Check the signature.
		valtype &vchSig =
		stacktop(-idxBottomSig + iSig);
		valtype &vchPubKey =
		stacktop(-idxBottomKey + iKey);

		// Note that only pubkeys associated with a
		// signature are checked for validity.
		if (!CheckTransactionSchnorrSignatureEncoding(
		vchSig, flags, serror) \|\|
		!CheckPubKeyEncoding(vchPubKey, flags,
		serror)) {
		// serror is set
		return false;
		}

		// Check signature
		if (!checker.CheckSig(vchSig, vchPubKey,
		scriptCode, flags)) {
		// This can fail if the signature is empty,
		// which also is a NULLFAILL error as the
		markblundebergUnsubmitted Not Done Inline Actions NULLFAIL markblundeberg: NULLFAIL
		// bitfield should have been null in this
		// situation.
		return set_error(serror,
		ScriptError::SIG_NULLFAIL);
		}
		}

		if ((checkBits >> iKey) != 0) {
		// This is a sanity check and should be
		// unrecheable.
		markblundebergUnsubmitted Not Done Inline Actions ditto markblundeberg: ditto
		return set_error(
		serror, ScriptError::INVALID_BIT_COUNT);
		}
		} else {
		// LEGACY MULTISIG (ECDSA / NULL)
// A bug causes CHECKMULTISIG to consume one extra		// A bug causes CHECKMULTISIG to consume one extra
// argument whose contents were not checked in any way.		// argument whose contents were not checked in any
		// way.
//		//
// Unfortunately this is a potential source of		// Unfortunately this is a potential source of
// mutability, so optionally verify it is exactly equal		// mutability, so optionally verify it is exactly
// to zero.		// equal to zero.
if ((flags & SCRIPT_VERIFY_NULLDUMMY) &&		if ((flags & SCRIPT_VERIFY_NULLDUMMY) &&
stacktop(-idxDummy).size()) {		stacktop(-idxDummy).size()) {
return set_error(serror,		return set_error(serror,
ScriptError::SIG_NULLDUMMY);		ScriptError::SIG_NULLDUMMY);
}		}

// Subset of script starting at the most recent
// codeseparator
CScript scriptCode(pbegincodehash, pend);

// Remove signature for pre-fork scripts		// Remove signature for pre-fork scripts
for (int k = 0; k < nSigsCount; k++) {		for (int k = 0; k < nSigsCount; k++) {
valtype &vchSig = stacktop(-idxTopSig - k);		valtype &vchSig = stacktop(-idxTopSig - k);
CleanupScriptCode(scriptCode, vchSig, flags);		CleanupScriptCode(scriptCode, vchSig, flags);
}		}

bool fSuccess = true;
int nSigsRemaining = nSigsCount;		int nSigsRemaining = nSigsCount;
int nKeysRemaining = nKeysCount;		int nKeysRemaining = nKeysCount;
while (fSuccess && nSigsRemaining > 0) {		while (fSuccess && nSigsRemaining > 0) {
valtype &vchSig = stacktop(		valtype &vchSig = stacktop(
-idxTopSig - (nSigsCount - nSigsRemaining));		-idxTopSig - (nSigsCount - nSigsRemaining));
valtype &vchPubKey = stacktop(		valtype &vchPubKey = stacktop(
-idxTopKey - (nKeysCount - nKeysRemaining));		-idxTopKey - (nKeysCount - nKeysRemaining));

// Note how this makes the exact order of		// Note how this makes the exact order of
// pubkey/signature evaluation distinguishable by		// pubkey/signature evaluation distinguishable
// CHECKMULTISIG NOT if the STRICTENC flag is set.		// by CHECKMULTISIG NOT if the STRICTENC flag is
// See the script_(in)valid tests for details.		// set. See the script_(in)valid tests for
		// details.
if (!CheckTransactionECDSASignatureEncoding(		if (!CheckTransactionECDSASignatureEncoding(
vchSig, flags, serror) \|\|		vchSig, flags, serror) \|\|
!CheckPubKeyEncoding(vchPubKey, flags,		!CheckPubKeyEncoding(vchPubKey, flags,
serror)) {		serror)) {
// serror is set		// serror is set
return false;		return false;
}		}

// Check signature		// Check signature
bool fOk = checker.CheckSig(vchSig, vchPubKey,		bool fOk = checker.CheckSig(vchSig, vchPubKey,
scriptCode, flags);		scriptCode, flags);

if (fOk) {		if (fOk) {
nSigsRemaining--;		nSigsRemaining--;
}		}
nKeysRemaining--;		nKeysRemaining--;

// If there are more signatures left than keys left,		// If there are more signatures left than keys
// then too many signatures have failed. Exit early,		// left, then too many signatures have failed.
// without checking any further signatures.		// Exit early, without checking any further
		// signatures.
if (nSigsRemaining > nKeysRemaining) {		if (nSigsRemaining > nKeysRemaining) {
fSuccess = false;		fSuccess = false;
}		}
}		}
		}

// If the operation failed, we require that all		// If the operation failed, we require that all
// signatures must be empty vector		// signatures must be empty vector
if (!fSuccess && (flags & SCRIPT_VERIFY_NULLFAIL)) {		if (!fSuccess && (flags & SCRIPT_VERIFY_NULLFAIL)) {
for (int i = 0; i < nSigsCount; i++) {		for (int i = 0; i < nSigsCount; i++) {
if (stacktop(-idxTopSig - i).size()) {		if (stacktop(-idxTopSig - i).size()) {
return set_error(serror,		return set_error(serror,
ScriptError::SIG_NULLFAIL);		ScriptError::SIG_NULLFAIL);
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