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Add CheckInputs() unit tests
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Check that cached script execution results are only valid for the same
script flags; that script execution checks are returned for non-cached
transactions; and that cached results are only valid for transactions
with the same witness hash.
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@sdaftuar @TheBlueMatt
sdaftuar authored and TheBlueMatt committed Jun 27, 2017
1 parent a3543af commit e3f9c05
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Showing 2 changed files with 288 additions and 2 deletions.
284 changes: 284 additions & 0 deletions src/test/txvalidationcache_tests.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -10,11 +10,17 @@
#include "txmempool.h"
#include "random.h"
#include "script/standard.h"
#include "script/sign.h"
#include "test/test_bitcoin.h"
#include "utiltime.h"
#include "core_io.h"
#include "keystore.h"
#include "policy/policy.h"

#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);

BOOST_AUTO_TEST_SUITE(tx_validationcache_tests)

static bool
Expand Down Expand Up @@ -84,4 +90,282 @@ BOOST_FIXTURE_TEST_CASE(tx_mempool_block_doublespend, TestChain100Setup)
BOOST_CHECK_EQUAL(mempool.size(), 0);
}

// Run CheckInputs (using pcoinsTip) on the given transaction, for all script
// flags. Test that CheckInputs passes for all flags that don't overlap with
// the failing_flags argument, but otherwise fails.
// CHECKLOCKTIMEVERIFY and CHECKSEQUENCEVERIFY (and future NOP codes that may
// get reassigned) have an interaction with DISCOURAGE_UPGRADABLE_NOPS: if
// the script flags used contain DISCOURAGE_UPGRADABLE_NOPS but don't contain
// CHECKLOCKTIMEVERIFY (or CHECKSEQUENCEVERIFY), but the script does contain
// OP_CHECKLOCKTIMEVERIFY (or OP_CHECKSEQUENCEVERIFY), then script execution
// should fail.
// Capture this interaction with the upgraded_nop argument: set it when evaluating
// any script flag that is implemented as an upgraded NOP code.
void ValidateCheckInputsForAllFlags(CMutableTransaction &tx, uint32_t failing_flags, bool add_to_cache, bool upgraded_nop)
{
PrecomputedTransactionData txdata(tx);
// If we add many more flags, this loop can get too expensive, but we can
// rewrite in the future to randomly pick a set of flags to evaluate.
for (uint32_t test_flags=0; test_flags < (1U << 16); test_flags += 1) {
CValidationState state;
// Filter out incompatible flag choices
if ((test_flags & SCRIPT_VERIFY_CLEANSTACK)) {
// CLEANSTACK requires P2SH and WITNESS, see VerifyScript() in
// script/interpreter.cpp
test_flags |= SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS;
}
if ((test_flags & SCRIPT_VERIFY_WITNESS)) {
// WITNESS requires P2SH
test_flags |= SCRIPT_VERIFY_P2SH;
}
bool ret = CheckInputs(tx, state, pcoinsTip, true, 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);
if (expected_return_value && upgraded_nop) {
// If the script flag being tested corresponds to an upgraded NOP,
// then script execution should fail if DISCOURAGE_UPGRADABLE_NOPS
// is set.
expected_return_value = !(test_flags & SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS);
}
BOOST_CHECK_EQUAL(ret, expected_return_value);

// Test the caching
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, pcoinsTip, true, 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, pcoinsTip, true, test_flags, true, add_to_cache, txdata, &scriptchecks));
BOOST_CHECK_EQUAL(scriptchecks.size(), tx.vin.size());
}
}
}

BOOST_FIXTURE_TEST_CASE(checkinputs_test, TestChain100Setup)
{
// Test that passing CheckInputs with one set of script flags doesn't imply
// that we would pass again with a different set of flags.
InitScriptExecutionCache();

CScript p2pk_scriptPubKey = CScript() << ToByteVector(coinbaseKey.GetPubKey()) << OP_CHECKSIG;
CScript p2sh_scriptPubKey = GetScriptForDestination(CScriptID(p2pk_scriptPubKey));
CScript p2pkh_scriptPubKey = GetScriptForDestination(coinbaseKey.GetPubKey().GetID());
CScript p2wpkh_scriptPubKey = GetScriptForWitness(p2pkh_scriptPubKey);

CBasicKeyStore keystore;
keystore.AddKey(coinbaseKey);
keystore.AddCScript(p2pk_scriptPubKey);

// flags to test: SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY, SCRIPT_VERIFY_CHECKSEQUENCE_VERIFY, SCRIPT_VERIFY_NULLDUMMY, uncompressed pubkey thing

// Create 2 outputs that match the three scripts above, spending the first
// coinbase tx.
CMutableTransaction spend_tx;

spend_tx.nVersion = 1;
spend_tx.vin.resize(1);
spend_tx.vin[0].prevout.hash = coinbaseTxns[0].GetHash();
spend_tx.vin[0].prevout.n = 0;
spend_tx.vout.resize(4);
spend_tx.vout[0].nValue = 11*CENT;
spend_tx.vout[0].scriptPubKey = p2sh_scriptPubKey;
spend_tx.vout[1].nValue = 11*CENT;
spend_tx.vout[1].scriptPubKey = p2wpkh_scriptPubKey;
spend_tx.vout[2].nValue = 11*CENT;
spend_tx.vout[2].scriptPubKey = CScript() << OP_CHECKLOCKTIMEVERIFY << OP_DROP << ToByteVector(coinbaseKey.GetPubKey()) << OP_CHECKSIG;
spend_tx.vout[3].nValue = 11*CENT;
spend_tx.vout[3].scriptPubKey = CScript() << OP_CHECKSEQUENCEVERIFY << OP_DROP << ToByteVector(coinbaseKey.GetPubKey()) << OP_CHECKSIG;

// Sign, with a non-DER signature
{
std::vector<unsigned char> vchSig;
uint256 hash = SignatureHash(p2pk_scriptPubKey, spend_tx, 0, SIGHASH_ALL, 0, SIGVERSION_BASE);
BOOST_CHECK(coinbaseKey.Sign(hash, vchSig));
vchSig.push_back((unsigned char) 0); // padding byte makes this non-DER
vchSig.push_back((unsigned char)SIGHASH_ALL);
spend_tx.vin[0].scriptSig << vchSig;
}

LOCK(cs_main);

// Test that invalidity under a set of flags doesn't preclude validity
// under other (eg consensus) flags.
// spend_tx is invalid according to DERSIG
CValidationState state;
{
PrecomputedTransactionData ptd_spend_tx(spend_tx);

BOOST_CHECK(!CheckInputs(spend_tx, state, pcoinsTip, true, 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(spend_tx, state, pcoinsTip, true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_DERSIG, true, true, ptd_spend_tx, &scriptchecks));
BOOST_CHECK_EQUAL(scriptchecks.size(), 1);

// Test that CheckInputs returns true iff DERSIG-enforcing flags are
// not present. Don't add these checks to the cache, so that we can
// test later that block validation works fine in the absence of cached
// successes.
ValidateCheckInputsForAllFlags(spend_tx, SCRIPT_VERIFY_DERSIG | SCRIPT_VERIFY_LOW_S | SCRIPT_VERIFY_STRICTENC, false, false);

// And if we produce a block with this tx, it should be valid (DERSIG not
// enabled yet), even though there's no cache entry.
CBlock block;

block = CreateAndProcessBlock({spend_tx}, p2pk_scriptPubKey);
BOOST_CHECK(chainActive.Tip()->GetBlockHash() == block.GetHash());
BOOST_CHECK(pcoinsTip->GetBestBlock() == block.GetHash());
}

// Test P2SH: construct a transaction that is valid without P2SH, and
// then test validity with P2SH.
{
CMutableTransaction invalid_under_p2sh_tx;
invalid_under_p2sh_tx.nVersion = 1;
invalid_under_p2sh_tx.vin.resize(1);
invalid_under_p2sh_tx.vin[0].prevout.hash = spend_tx.GetHash();
invalid_under_p2sh_tx.vin[0].prevout.n = 0;
invalid_under_p2sh_tx.vout.resize(1);
invalid_under_p2sh_tx.vout[0].nValue = 11*CENT;
invalid_under_p2sh_tx.vout[0].scriptPubKey = p2pk_scriptPubKey;
std::vector<unsigned char> vchSig2(p2pk_scriptPubKey.begin(), p2pk_scriptPubKey.end());
invalid_under_p2sh_tx.vin[0].scriptSig << vchSig2;

ValidateCheckInputsForAllFlags(invalid_under_p2sh_tx, SCRIPT_VERIFY_P2SH, true, false);
}

// Test CHECKLOCKTIMEVERIFY
{
CMutableTransaction invalid_with_cltv_tx;
invalid_with_cltv_tx.nVersion = 1;
invalid_with_cltv_tx.nLockTime = 100;
invalid_with_cltv_tx.vin.resize(1);
invalid_with_cltv_tx.vin[0].prevout.hash = spend_tx.GetHash();
invalid_with_cltv_tx.vin[0].prevout.n = 2;
invalid_with_cltv_tx.vin[0].nSequence = 0;
invalid_with_cltv_tx.vout.resize(1);
invalid_with_cltv_tx.vout[0].nValue = 11*CENT;
invalid_with_cltv_tx.vout[0].scriptPubKey = p2pk_scriptPubKey;

// Sign
std::vector<unsigned char> vchSig;
uint256 hash = SignatureHash(spend_tx.vout[2].scriptPubKey, invalid_with_cltv_tx, 0, SIGHASH_ALL, 0, SIGVERSION_BASE);
BOOST_CHECK(coinbaseKey.Sign(hash, vchSig));
vchSig.push_back((unsigned char)SIGHASH_ALL);
invalid_with_cltv_tx.vin[0].scriptSig = CScript() << vchSig << 101;

ValidateCheckInputsForAllFlags(invalid_with_cltv_tx, SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY, true, true);

// Make it valid, and check again
invalid_with_cltv_tx.vin[0].scriptSig = CScript() << vchSig << 100;
CValidationState state;
PrecomputedTransactionData txdata(invalid_with_cltv_tx);
BOOST_CHECK(CheckInputs(invalid_with_cltv_tx, state, pcoinsTip, true, SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY, true, true, txdata, nullptr));
}

// TEST CHECKSEQUENCEVERIFY
{
CMutableTransaction invalid_with_csv_tx;
invalid_with_csv_tx.nVersion = 2;
invalid_with_csv_tx.vin.resize(1);
invalid_with_csv_tx.vin[0].prevout.hash = spend_tx.GetHash();
invalid_with_csv_tx.vin[0].prevout.n = 3;
invalid_with_csv_tx.vin[0].nSequence = 100;
invalid_with_csv_tx.vout.resize(1);
invalid_with_csv_tx.vout[0].nValue = 11*CENT;
invalid_with_csv_tx.vout[0].scriptPubKey = p2pk_scriptPubKey;

// Sign
std::vector<unsigned char> vchSig;
uint256 hash = SignatureHash(spend_tx.vout[3].scriptPubKey, invalid_with_csv_tx, 0, SIGHASH_ALL, 0, SIGVERSION_BASE);
BOOST_CHECK(coinbaseKey.Sign(hash, vchSig));
vchSig.push_back((unsigned char)SIGHASH_ALL);
invalid_with_csv_tx.vin[0].scriptSig = CScript() << vchSig << 101;

ValidateCheckInputsForAllFlags(invalid_with_csv_tx, SCRIPT_VERIFY_CHECKSEQUENCEVERIFY, true, true);

// Make it valid, and check again
invalid_with_csv_tx.vin[0].scriptSig = CScript() << vchSig << 100;
CValidationState state;
PrecomputedTransactionData txdata(invalid_with_csv_tx);
BOOST_CHECK(CheckInputs(invalid_with_csv_tx, state, pcoinsTip, true, SCRIPT_VERIFY_CHECKSEQUENCEVERIFY, true, true, txdata, nullptr));
}

// TODO: add tests for remaining script flags

// Test that passing CheckInputs with a valid witness doesn't imply success
// for the same tx with a different witness.
{
CMutableTransaction valid_with_witness_tx;
valid_with_witness_tx.nVersion = 1;
valid_with_witness_tx.vin.resize(1);
valid_with_witness_tx.vin[0].prevout.hash = spend_tx.GetHash();
valid_with_witness_tx.vin[0].prevout.n = 1;
valid_with_witness_tx.vout.resize(1);
valid_with_witness_tx.vout[0].nValue = 11*CENT;
valid_with_witness_tx.vout[0].scriptPubKey = p2pk_scriptPubKey;

// Sign
SignatureData sigdata;
ProduceSignature(MutableTransactionSignatureCreator(&keystore, &valid_with_witness_tx, 0, 11*CENT, SIGHASH_ALL), spend_tx.vout[1].scriptPubKey, sigdata);
UpdateTransaction(valid_with_witness_tx, 0, sigdata);

// This should be valid under all script flags.
ValidateCheckInputsForAllFlags(valid_with_witness_tx, 0, true, false);

// Remove the witness, and check that it is now invalid.
valid_with_witness_tx.vin[0].scriptWitness.SetNull();
ValidateCheckInputsForAllFlags(valid_with_witness_tx, SCRIPT_VERIFY_WITNESS, true, false);
}

{
// Test a transaction with multiple inputs.
CMutableTransaction tx;

tx.nVersion = 1;
tx.vin.resize(2);
tx.vin[0].prevout.hash = spend_tx.GetHash();
tx.vin[0].prevout.n = 0;
tx.vin[1].prevout.hash = spend_tx.GetHash();
tx.vin[1].prevout.n = 1;
tx.vout.resize(1);
tx.vout[0].nValue = 22*CENT;
tx.vout[0].scriptPubKey = p2pk_scriptPubKey;

// Sign
for (int i=0; i<2; ++i) {
SignatureData sigdata;
ProduceSignature(MutableTransactionSignatureCreator(&keystore, &tx, i, 11*CENT, SIGHASH_ALL), spend_tx.vout[i].scriptPubKey, sigdata);
UpdateTransaction(tx, i, sigdata);
}

// This should be valid under all script flags
ValidateCheckInputsForAllFlags(tx, 0, true, false);

// Check that if the second input is invalid, but the first input is
// valid, the transaction is not cached.
// Invalidate vin[1]
tx.vin[1].scriptWitness.SetNull();

CValidationState state;
PrecomputedTransactionData txdata(tx);
// This transaction is now invalid under segwit, because of the second input.
BOOST_CHECK(!CheckInputs(tx, state, pcoinsTip, true, 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(tx, state, pcoinsTip, true, 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(), 2);
}
}

BOOST_AUTO_TEST_SUITE_END()
6 changes: 4 additions & 2 deletions src/validation.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -190,7 +190,7 @@ enum FlushStateMode {
static bool FlushStateToDisk(const CChainParams& chainParams, CValidationState &state, FlushStateMode mode, int nManualPruneHeight=0);
static void FindFilesToPruneManual(std::set<int>& setFilesToPrune, int nManualPruneHeight);
static void FindFilesToPrune(std::set<int>& setFilesToPrune, uint64_t nPruneAfterHeight);
static 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, bool fScriptChecks, unsigned int flags, bool cacheSigStore, bool cacheFullScriptStore, PrecomputedTransactionData& txdata, std::vector<CScriptCheck> *pvChecks = nullptr);
static FILE* OpenUndoFile(const CDiskBlockPos &pos, bool fReadOnly = false);

bool CheckFinalTx(const CTransaction &tx, int flags)
Expand Down Expand Up @@ -1232,8 +1232,10 @@ void InitScriptExecutionCache() {
* Setting cacheSigStore/cacheFullScriptStore to false will remove elements from the corresponding cache
* which are matched. This is useful for checking blocks where we will likely never need the cache
* entry again.
*
* Non-static (and re-declared) in src/test/txvalidationcache_tests.cpp
*/
static 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, bool fScriptChecks, unsigned int flags, bool cacheSigStore, bool cacheFullScriptStore, PrecomputedTransactionData& txdata, std::vector<CScriptCheck> *pvChecks)
{
if (!tx.IsCoinBase())
{
Expand Down

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