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Merge #13868: Remove unused fScriptChecks parameter from CheckInputs

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9b92538ade Remove unused fScriptChecks parameter from CheckInputs (Matt Corallo)

Pull request description:

  fScriptChecks = false just short-circuits the entire function, so
  passing it in is entirely useless.

  This is extracted from #13233 /cc TheBlueMatt.

  Recommend reviewing with `git show --ignore-all-space`, i.e.:
  https://github.com/bitcoin/bitcoin/pull/13868/files?w=1

ACKs for top commit:
  TheBlueMatt:
    utACK 9b92538ade. Checked diff had no functional change and new comment copy looks correct.
  kallewoof:
    ACK 9b92538ade
  ajtowns:
    ACK 9b92538ade ; code review, checked tests work. Looks right to me, and fanquake's notes make sense. Could change the coinbase early exit to `assert(!tx.IsCoinBase());`.
  fanquake:
    ACK 9b92538ade - Notes / testing below.

Tree-SHA512: add253a3e8cf4b33eddbc49efcec333c14b5ea61c7d34e43230351d40cff6adc919a75b91c72c4de8647a395284db74a61639f4c67848d4b2fec3a705b557790
This commit is contained in:
fanquake 2019-09-02 15:36:57 +08:00
commit 6519be6054
No known key found for this signature in database
GPG key ID: 2EEB9F5CC09526C1
2 changed files with 90 additions and 94 deletions
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20
src/test/txvalidationcache_tests.cpp
View file

@ -13,7 +13,7 @@
#include <boost/test/unit_test.hpp>
bool CheckInputs(const CTransaction& tx, CValidationState &state, const CCoinsViewCache &inputs, bool fScriptChecks, unsigned int flags, bool cacheSigStore, bool cacheFullScriptStore, PrecomputedTransactionData& txdata, std::vector<CScriptCheck> *pvChecks);
bool CheckInputs(const CTransaction& tx, CValidationState &state, const CCoinsViewCache &inputs, unsigned int flags, bool cacheSigStore, bool cacheFullScriptStore, PrecomputedTransactionData& txdata, std::vector<CScriptCheck> *pvChecks);
BOOST_AUTO_TEST_SUITE(tx_validationcache_tests)
@ -125,7 +125,7 @@ static void ValidateCheckInputsForAllFlags(const CTransaction &tx, uint32_t fail
// WITNESS requires P2SH
test_flags |= SCRIPT_VERIFY_P2SH;
}
bool ret = CheckInputs(tx, state, &::ChainstateActive().CoinsTip(), true, test_flags, true, add_to_cache, txdata, nullptr);
bool ret = CheckInputs(tx, state, &::ChainstateActive().CoinsTip(), test_flags, true, add_to_cache, txdata, nullptr);
// CheckInputs should succeed iff test_flags doesn't intersect with
// failing_flags
bool expected_return_value = !(test_flags & failing_flags);
@ -135,13 +135,13 @@ static void ValidateCheckInputsForAllFlags(const CTransaction &tx, uint32_t fail
if (ret && add_to_cache) {
// Check that we get a cache hit if the tx was valid
std::vector<CScriptCheck> scriptchecks;
BOOST_CHECK(CheckInputs(tx, state, &::ChainstateActive().CoinsTip(), true, test_flags, true, add_to_cache, txdata, &scriptchecks));
BOOST_CHECK(CheckInputs(tx, state, &::ChainstateActive().CoinsTip(), test_flags, true, add_to_cache, txdata, &scriptchecks));
BOOST_CHECK(scriptchecks.empty());
} else {
// Check that we get script executions to check, if the transaction
// was invalid, or we didn't add to cache.
std::vector<CScriptCheck> scriptchecks;
BOOST_CHECK(CheckInputs(tx, state, &::ChainstateActive().CoinsTip(), true, test_flags, true, add_to_cache, txdata, &scriptchecks));
BOOST_CHECK(CheckInputs(tx, state, &::ChainstateActive().CoinsTip(), test_flags, true, add_to_cache, txdata, &scriptchecks));
BOOST_CHECK_EQUAL(scriptchecks.size(), tx.vin.size());
}
}
@ -204,13 +204,13 @@ BOOST_FIXTURE_TEST_CASE(checkinputs_test, TestChain100Setup)
CValidationState state;
PrecomputedTransactionData ptd_spend_tx(spend_tx);
BOOST_CHECK(!CheckInputs(CTransaction(spend_tx), state, &::ChainstateActive().CoinsTip(), true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_DERSIG, true, true, ptd_spend_tx, nullptr));
BOOST_CHECK(!CheckInputs(CTransaction(spend_tx), state, &::ChainstateActive().CoinsTip(), SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_DERSIG, true, true, ptd_spend_tx, nullptr));
// If we call again asking for scriptchecks (as happens in
// ConnectBlock), we should add a script check object for this -- we're
// not caching invalidity (if that changes, delete this test case).
std::vector<CScriptCheck> scriptchecks;
BOOST_CHECK(CheckInputs(CTransaction(spend_tx), state, &::ChainstateActive().CoinsTip(), true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_DERSIG, true, true, ptd_spend_tx, &scriptchecks));
BOOST_CHECK(CheckInputs(CTransaction(spend_tx), state, &::ChainstateActive().CoinsTip(), SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_DERSIG, true, true, ptd_spend_tx, &scriptchecks));
BOOST_CHECK_EQUAL(scriptchecks.size(), 1U);
// Test that CheckInputs returns true iff DERSIG-enforcing flags are
@ -272,7 +272,7 @@ BOOST_FIXTURE_TEST_CASE(checkinputs_test, TestChain100Setup)
invalid_with_cltv_tx.vin[0].scriptSig = CScript() << vchSig << 100;
CValidationState state;
PrecomputedTransactionData txdata(invalid_with_cltv_tx);
BOOST_CHECK(CheckInputs(CTransaction(invalid_with_cltv_tx), state, ::ChainstateActive().CoinsTip(), true, SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY, true, true, txdata, nullptr));
BOOST_CHECK(CheckInputs(CTransaction(invalid_with_cltv_tx), state, ::ChainstateActive().CoinsTip(), SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY, true, true, txdata, nullptr));
}
// TEST CHECKSEQUENCEVERIFY
@ -300,7 +300,7 @@ BOOST_FIXTURE_TEST_CASE(checkinputs_test, TestChain100Setup)
invalid_with_csv_tx.vin[0].scriptSig = CScript() << vchSig << 100;
CValidationState state;
PrecomputedTransactionData txdata(invalid_with_csv_tx);
BOOST_CHECK(CheckInputs(CTransaction(invalid_with_csv_tx), state, &::ChainstateActive().CoinsTip(), true, SCRIPT_VERIFY_CHECKSEQUENCEVERIFY, true, true, txdata, nullptr));
BOOST_CHECK(CheckInputs(CTransaction(invalid_with_csv_tx), state, &::ChainstateActive().CoinsTip(), SCRIPT_VERIFY_CHECKSEQUENCEVERIFY, true, true, txdata, nullptr));
}
// TODO: add tests for remaining script flags
@ -362,12 +362,12 @@ BOOST_FIXTURE_TEST_CASE(checkinputs_test, TestChain100Setup)
CValidationState state;
PrecomputedTransactionData txdata(tx);
// This transaction is now invalid under segwit, because of the second input.
BOOST_CHECK(!CheckInputs(CTransaction(tx), state, &::ChainstateActive().CoinsTip(), true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS, true, true, txdata, nullptr));
BOOST_CHECK(!CheckInputs(CTransaction(tx), state, &::ChainstateActive().CoinsTip(), SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS, true, true, txdata, nullptr));
std::vector<CScriptCheck> scriptchecks;
// Make sure this transaction was not cached (ie because the first
// input was valid)
BOOST_CHECK(CheckInputs(CTransaction(tx), state, &::ChainstateActive().CoinsTip(), true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS, true, true, txdata, &scriptchecks));
BOOST_CHECK(CheckInputs(CTransaction(tx), state, &::ChainstateActive().CoinsTip(), SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS, true, true, txdata, &scriptchecks));
// Should get 2 script checks back -- caching is on a whole-transaction basis.
BOOST_CHECK_EQUAL(scriptchecks.size(), 2U);
}

164
src/validation.cpp
View file

@ -184,7 +184,7 @@ std::unique_ptr<CBlockTreeDB> pblocktree;
// See definition for documentation
static void FindFilesToPruneManual(std::set<int>& setFilesToPrune, int nManualPruneHeight);
static void FindFilesToPrune(std::set<int>& setFilesToPrune, uint64_t nPruneAfterHeight);
bool CheckInputs(const CTransaction& tx, CValidationState &state, const CCoinsViewCache &inputs, bool fScriptChecks, unsigned int flags, bool cacheSigStore, bool cacheFullScriptStore, PrecomputedTransactionData& txdata, std::vector<CScriptCheck> *pvChecks = nullptr);
bool CheckInputs(const CTransaction& tx, CValidationState &state, const CCoinsViewCache &inputs, unsigned int flags, bool cacheSigStore, bool cacheFullScriptStore, PrecomputedTransactionData& txdata, std::vector<CScriptCheck> *pvChecks = nullptr);
static FILE* OpenUndoFile(const FlatFilePos &pos, bool fReadOnly = false);
static FlatFileSeq BlockFileSeq();
static FlatFileSeq UndoFileSeq();
@ -425,7 +425,7 @@ static bool CheckInputsFromMempoolAndCache(const CTransaction& tx, CValidationSt
}
}
return CheckInputs(tx, state, view, true, flags, cacheSigStore, true, txdata);
return CheckInputs(tx, state, view, flags, cacheSigStore, true, txdata);
}
/**
@ -773,15 +773,17 @@ static bool AcceptToMemoryPoolWorker(const CChainParams& chainparams, CTxMemPool
constexpr unsigned int scriptVerifyFlags = STANDARD_SCRIPT_VERIFY_FLAGS;
// Check against previous transactions
// This is done last to help prevent CPU exhaustion denial-of-service attacks.
// The first loop above does all the inexpensive checks.
// Only if ALL inputs pass do we perform expensive ECDSA signature checks.
// Helps prevent CPU exhaustion denial-of-service attacks.
PrecomputedTransactionData txdata(tx);
if (!CheckInputs(tx, state, view, true, scriptVerifyFlags, true, false, txdata)) {
if (!CheckInputs(tx, state, view, scriptVerifyFlags, true, false, txdata)) {
// SCRIPT_VERIFY_CLEANSTACK requires SCRIPT_VERIFY_WITNESS, so we
// need to turn both off, and compare against just turning off CLEANSTACK
// to see if the failure is specifically due to witness validation.
CValidationState stateDummy; // Want reported failures to be from first CheckInputs
if (!tx.HasWitness() && CheckInputs(tx, stateDummy, view, true, scriptVerifyFlags & ~(SCRIPT_VERIFY_WITNESS | SCRIPT_VERIFY_CLEANSTACK), true, false, txdata) &&
!CheckInputs(tx, stateDummy, view, true, scriptVerifyFlags & ~SCRIPT_VERIFY_CLEANSTACK, true, false, txdata)) {
if (!tx.HasWitness() && CheckInputs(tx, stateDummy, view, scriptVerifyFlags & ~(SCRIPT_VERIFY_WITNESS | SCRIPT_VERIFY_CLEANSTACK), true, false, txdata) &&
!CheckInputs(tx, stateDummy, view, scriptVerifyFlags & ~SCRIPT_VERIFY_CLEANSTACK, true, false, txdata)) {
// Only the witness is missing, so the transaction itself may be fine.
state.Invalid(ValidationInvalidReason::TX_WITNESS_MUTATED, false,
state.GetRejectCode(), state.GetRejectReason(), state.GetDebugMessage());
@ -1298,90 +1300,79 @@ void InitScriptExecutionCache() {
*
* Non-static (and re-declared) in src/test/txvalidationcache_tests.cpp
*/
bool CheckInputs(const CTransaction& tx, CValidationState &state, const CCoinsViewCache &inputs, bool fScriptChecks, unsigned int flags, bool cacheSigStore, bool cacheFullScriptStore, PrecomputedTransactionData& txdata, std::vector<CScriptCheck> *pvChecks) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
bool CheckInputs(const CTransaction& tx, CValidationState &state, const CCoinsViewCache &inputs, unsigned int flags, bool cacheSigStore, bool cacheFullScriptStore, PrecomputedTransactionData& txdata, std::vector<CScriptCheck> *pvChecks) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
{
if (!tx.IsCoinBase())
{
if (pvChecks)
pvChecks->reserve(tx.vin.size());
if (tx.IsCoinBase()) return true;
// The first loop above does all the inexpensive checks.
// Only if ALL inputs pass do we perform expensive ECDSA signature checks.
// Helps prevent CPU exhaustion attacks.
if (pvChecks) {
pvChecks->reserve(tx.vin.size());
}
// Skip script verification when connecting blocks under the
// assumevalid block. Assuming the assumevalid block is valid this
// is safe because block merkle hashes are still computed and checked,
// Of course, if an assumed valid block is invalid due to false scriptSigs
// this optimization would allow an invalid chain to be accepted.
if (fScriptChecks) {
// First check if script executions have been cached with the same
// flags. Note that this assumes that the inputs provided are
// correct (ie that the transaction hash which is in tx's prevouts
// properly commits to the scriptPubKey in the inputs view of that
// transaction).
uint256 hashCacheEntry;
// We only use the first 19 bytes of nonce to avoid a second SHA
// round - giving us 19 + 32 + 4 = 55 bytes (+ 8 + 1 = 64)
static_assert(55 - sizeof(flags) - 32 >= 128/8, "Want at least 128 bits of nonce for script execution cache");
CSHA256().Write(scriptExecutionCacheNonce.begin(), 55 - sizeof(flags) - 32).Write(tx.GetWitnessHash().begin(), 32).Write((unsigned char*)&flags, sizeof(flags)).Finalize(hashCacheEntry.begin());
AssertLockHeld(cs_main); //TODO: Remove this requirement by making CuckooCache not require external locks
if (scriptExecutionCache.contains(hashCacheEntry, !cacheFullScriptStore)) {
return true;
}
for (unsigned int i = 0; i < tx.vin.size(); i++) {
const COutPoint &prevout = tx.vin[i].prevout;
const Coin& coin = inputs.AccessCoin(prevout);
assert(!coin.IsSpent());
// We very carefully only pass in things to CScriptCheck which
// are clearly committed to by tx' witness hash. This provides
// a sanity check that our caching is not introducing consensus
// failures through additional data in, eg, the coins being
// spent being checked as a part of CScriptCheck.
// Verify signature
CScriptCheck check(coin.out, tx, i, flags, cacheSigStore, &txdata);
if (pvChecks) {
pvChecks->push_back(CScriptCheck());
check.swap(pvChecks->back());
} else if (!check()) {
if (flags & STANDARD_NOT_MANDATORY_VERIFY_FLAGS) {
// Check whether the failure was caused by a
// non-mandatory script verification check, such as
// non-standard DER encodings or non-null dummy
// arguments; if so, ensure we return NOT_STANDARD
// instead of CONSENSUS to avoid downstream users
// splitting the network between upgraded and
// non-upgraded nodes by banning CONSENSUS-failing
// data providers.
CScriptCheck check2(coin.out, tx, i,
flags & ~STANDARD_NOT_MANDATORY_VERIFY_FLAGS, cacheSigStore, &txdata);
if (check2())
return state.Invalid(ValidationInvalidReason::TX_NOT_STANDARD, false, REJECT_NONSTANDARD, strprintf("non-mandatory-script-verify-flag (%s)", ScriptErrorString(check.GetScriptError())));
}
// MANDATORY flag failures correspond to
// ValidationInvalidReason::CONSENSUS. Because CONSENSUS
// failures are the most serious case of validation
// failures, we may need to consider using
// RECENT_CONSENSUS_CHANGE for any script failure that
// could be due to non-upgraded nodes which we may want to
// support, to avoid splitting the network (but this
// depends on the details of how net_processing handles
// such errors).
return state.Invalid(ValidationInvalidReason::CONSENSUS, false, REJECT_INVALID, strprintf("mandatory-script-verify-flag-failed (%s)", ScriptErrorString(check.GetScriptError())));
}
}
if (cacheFullScriptStore && !pvChecks) {
// We executed all of the provided scripts, and were told to
// cache the result. Do so now.
scriptExecutionCache.insert(hashCacheEntry);
// First check if script executions have been cached with the same
// flags. Note that this assumes that the inputs provided are
// correct (ie that the transaction hash which is in tx's prevouts
// properly commits to the scriptPubKey in the inputs view of that
// transaction).
uint256 hashCacheEntry;
// We only use the first 19 bytes of nonce to avoid a second SHA
// round - giving us 19 + 32 + 4 = 55 bytes (+ 8 + 1 = 64)
static_assert(55 - sizeof(flags) - 32 >= 128/8, "Want at least 128 bits of nonce for script execution cache");
CSHA256().Write(scriptExecutionCacheNonce.begin(), 55 - sizeof(flags) - 32).Write(tx.GetWitnessHash().begin(), 32).Write((unsigned char*)&flags, sizeof(flags)).Finalize(hashCacheEntry.begin());
AssertLockHeld(cs_main); //TODO: Remove this requirement by making CuckooCache not require external locks
if (scriptExecutionCache.contains(hashCacheEntry, !cacheFullScriptStore)) {
return true;
}
for (unsigned int i = 0; i < tx.vin.size(); i++) {
const COutPoint &prevout = tx.vin[i].prevout;
const Coin& coin = inputs.AccessCoin(prevout);
assert(!coin.IsSpent());
// We very carefully only pass in things to CScriptCheck which
// are clearly committed to by tx' witness hash. This provides
// a sanity check that our caching is not introducing consensus
// failures through additional data in, eg, the coins being
// spent being checked as a part of CScriptCheck.
// Verify signature
CScriptCheck check(coin.out, tx, i, flags, cacheSigStore, &txdata);
if (pvChecks) {
pvChecks->push_back(CScriptCheck());
check.swap(pvChecks->back());
} else if (!check()) {
if (flags & STANDARD_NOT_MANDATORY_VERIFY_FLAGS) {
// Check whether the failure was caused by a
// non-mandatory script verification check, such as
// non-standard DER encodings or non-null dummy
// arguments; if so, ensure we return NOT_STANDARD
// instead of CONSENSUS to avoid downstream users
// splitting the network between upgraded and
// non-upgraded nodes by banning CONSENSUS-failing
// data providers.
CScriptCheck check2(coin.out, tx, i,
flags & ~STANDARD_NOT_MANDATORY_VERIFY_FLAGS, cacheSigStore, &txdata);
if (check2())
return state.Invalid(ValidationInvalidReason::TX_NOT_STANDARD, false, REJECT_NONSTANDARD, strprintf("non-mandatory-script-verify-flag (%s)", ScriptErrorString(check.GetScriptError())));
}
// MANDATORY flag failures correspond to
// ValidationInvalidReason::CONSENSUS. Because CONSENSUS
// failures are the most serious case of validation
// failures, we may need to consider using
// RECENT_CONSENSUS_CHANGE for any script failure that
// could be due to non-upgraded nodes which we may want to
// support, to avoid splitting the network (but this
// depends on the details of how net_processing handles
// such errors).
return state.Invalid(ValidationInvalidReason::CONSENSUS, false, REJECT_INVALID, strprintf("mandatory-script-verify-flag-failed (%s)", ScriptErrorString(check.GetScriptError())));
}
}
if (cacheFullScriptStore && !pvChecks) {
// We executed all of the provided scripts, and were told to
// cache the result. Do so now.
scriptExecutionCache.insert(hashCacheEntry);
}
return true;
}
@ -1769,6 +1760,11 @@ bool CChainState::ConnectBlock(const CBlock& block, CValidationState& state, CBl
pindexBestHeader->GetAncestor(pindex->nHeight) == pindex &&
pindexBestHeader->nChainWork >= nMinimumChainWork) {
// This block is a member of the assumed verified chain and an ancestor of the best header.
// Script verification is skipped when connecting blocks under the
// assumevalid block. Assuming the assumevalid block is valid this
// is safe because block merkle hashes are still computed and checked,
// Of course, if an assumed valid block is invalid due to false scriptSigs
// this optimization would allow an invalid chain to be accepted.
// The equivalent time check discourages hash power from extorting the network via DOS attack
// into accepting an invalid block through telling users they must manually set assumevalid.
// Requiring a software change or burying the invalid block, regardless of the setting, makes
@ -1952,7 +1948,7 @@ bool CChainState::ConnectBlock(const CBlock& block, CValidationState& state, CBl
{
std::vector<CScriptCheck> vChecks;
bool fCacheResults = fJustCheck; /* Don't cache results if we're actually connecting blocks (still consult the cache, though) */
if (!CheckInputs(tx, state, view, fScriptChecks, flags, fCacheResults, fCacheResults, txdata[i], nScriptCheckThreads ? &vChecks : nullptr)) {
if (fScriptChecks && !CheckInputs(tx, state, view, flags, fCacheResults, fCacheResults, txdata[i], nScriptCheckThreads ? &vChecks : nullptr)) {
if (state.GetReason() == ValidationInvalidReason::TX_NOT_STANDARD) {
// CheckInputs may return NOT_STANDARD for extra flags we passed,
// but we can't return that, as it's not defined for a block, so