Avoid storing a reference passed to SignatureChecker constructors

src/bitcoin-tx.cpp

@@ -436,7 +436,7 @@ static void MutateTxSign(CMutableTransaction& tx, const string& flagStr)
         BOOST_FOREACH(const CTransaction& txv, txVariants) {
             txin.scriptSig = CombineSignatures(prevPubKey, mergedTx, i, txin.scriptSig, txv.vin[i].scriptSig);
         }
-        if (!VerifyScript(txin.scriptSig, prevPubKey, STANDARD_SCRIPT_VERIFY_FLAGS, MutableTransactionSignatureChecker(mergedTx, i)))
+        if (!VerifyScript(txin.scriptSig, prevPubKey, STANDARD_SCRIPT_VERIFY_FLAGS, MutableTransactionSignatureChecker(&mergedTx, i)))
             fComplete = false;
     }
 

src/main.cpp

@@ -1422,7 +1422,7 @@ void UpdateCoins(const CTransaction& tx, CValidationState &state, CCoinsViewCach
 
 bool CScriptCheck::operator()() {
     const CScript &scriptSig = ptxTo->vin[nIn].scriptSig;
-    if (!VerifyScript(scriptSig, scriptPubKey, nFlags, CachingTransactionSignatureChecker(*ptxTo, nIn, cacheStore), &error)) {
+    if (!VerifyScript(scriptSig, scriptPubKey, nFlags, CachingTransactionSignatureChecker(ptxTo, nIn, cacheStore), &error)) {
         return ::error("CScriptCheck(): %s:%d VerifySignature failed: %s", ptxTo->GetHash().ToString(), nIn, ScriptErrorString(error));
     }
     return true;

src/rpcrawtransaction.cpp

@@ -688,7 +688,7 @@ Value signrawtransaction(const Array& params, bool fHelp)
         BOOST_FOREACH(const CMutableTransaction& txv, txVariants) {
             txin.scriptSig = CombineSignatures(prevPubKey, mergedTx, i, txin.scriptSig, txv.vin[i].scriptSig);
         }
-        if (!VerifyScript(txin.scriptSig, prevPubKey, STANDARD_SCRIPT_VERIFY_FLAGS, MutableTransactionSignatureChecker(mergedTx, i)))
+        if (!VerifyScript(txin.scriptSig, prevPubKey, STANDARD_SCRIPT_VERIFY_FLAGS, MutableTransactionSignatureChecker(&mergedTx, i)))
             fComplete = false;
     }
 

src/script/bitcoinconsensus.cpp

@@ -78,7 +78,7 @@ int bitcoinconsensus_verify_script(const unsigned char *scriptPubKey, unsigned i
          // Regardless of the verification result, the tx did not error.
          set_error(err, bitcoinconsensus_ERR_OK);
 
-        return VerifyScript(tx.vin[nIn].scriptSig, CScript(scriptPubKey, scriptPubKey + scriptPubKeyLen), flags, TransactionSignatureChecker(tx, nIn), NULL);
+        return VerifyScript(tx.vin[nIn].scriptSig, CScript(scriptPubKey, scriptPubKey + scriptPubKeyLen), flags, TransactionSignatureChecker(&tx, nIn), NULL);
     } catch (const std::exception&) {
         return set_error(err, bitcoinconsensus_ERR_TX_DESERIALIZE); // Error deserializing
     }

src/script/interpreter.cpp

@@ -1076,7 +1076,7 @@ bool TransactionSignatureChecker::CheckSig(const vector<unsigned char>& vchSigIn
     int nHashType = vchSig.back();
     vchSig.pop_back();
 
-    uint256 sighash = SignatureHash(scriptCode, txTo, nIn, nHashType);
+    uint256 sighash = SignatureHash(scriptCode, *txTo, nIn, nHashType);
 
     if (!VerifySignature(vchSig, pubkey, sighash))
         return false;

src/script/interpreter.h

@@ -94,14 +94,14 @@ public:
 class TransactionSignatureChecker : public BaseSignatureChecker
 {
 private:
-    const CTransaction& txTo;
+    const CTransaction* txTo;
     unsigned int nIn;
 
 protected:
     virtual bool VerifySignature(const std::vector<unsigned char>& vchSig, const CPubKey& vchPubKey, const uint256& sighash) const;
 
 public:
-    TransactionSignatureChecker(const CTransaction& txToIn, unsigned int nInIn) : txTo(txToIn), nIn(nInIn) {}
+    TransactionSignatureChecker(const CTransaction* txToIn, unsigned int nInIn) : txTo(txToIn), nIn(nInIn) {}
     bool CheckSig(const std::vector<unsigned char>& scriptSig, const std::vector<unsigned char>& vchPubKey, const CScript& scriptCode) const;
 };
 
@@ -111,7 +111,7 @@ private:
     const CTransaction txTo;
 
 public:
-    MutableTransactionSignatureChecker(const CMutableTransaction& txToIn, unsigned int nInIn) : TransactionSignatureChecker(txTo, nInIn), txTo(txToIn) {}
+    MutableTransactionSignatureChecker(const CMutableTransaction* txToIn, unsigned int nInIn) : TransactionSignatureChecker(&txTo, nInIn), txTo(*txToIn) {}
 };
 
 bool EvalScript(std::vector<std::vector<unsigned char> >& stack, const CScript& script, unsigned int flags, const BaseSignatureChecker& checker, ScriptError* error = NULL);

src/script/sigcache.h

@@ -18,7 +18,7 @@ private:
     bool store;
 
 public:
-    CachingTransactionSignatureChecker(const CTransaction& txToIn, unsigned int nInIn, bool storeIn=true) : TransactionSignatureChecker(txToIn, nInIn), store(storeIn) {}
+    CachingTransactionSignatureChecker(const CTransaction* txToIn, unsigned int nInIn, bool storeIn=true) : TransactionSignatureChecker(txToIn, nInIn), store(storeIn) {}
 
     bool VerifySignature(const std::vector<unsigned char>& vchSig, const CPubKey& vchPubKey, const uint256& sighash) const;
 };

src/script/sign.cpp

@@ -123,7 +123,7 @@ bool SignSignature(const CKeyStore &keystore, const CScript& fromPubKey, CMutabl
     }
 
     // Test solution
-    return VerifyScript(txin.scriptSig, fromPubKey, STANDARD_SCRIPT_VERIFY_FLAGS, MutableTransactionSignatureChecker(txTo, nIn));
+    return VerifyScript(txin.scriptSig, fromPubKey, STANDARD_SCRIPT_VERIFY_FLAGS, MutableTransactionSignatureChecker(&txTo, nIn));
 }
 
 bool SignSignature(const CKeyStore &keystore, const CTransaction& txFrom, CMutableTransaction& txTo, unsigned int nIn, int nHashType)
@@ -174,7 +174,7 @@ static CScript CombineMultisig(const CScript& scriptPubKey, const CTransaction&
             if (sigs.count(pubkey))
                 continue; // Already got a sig for this pubkey
 
-            if (TransactionSignatureChecker(txTo, nIn).CheckSig(sig, pubkey, scriptPubKey))
+            if (TransactionSignatureChecker(&txTo, nIn).CheckSig(sig, pubkey, scriptPubKey))
             {
                 sigs[pubkey] = sig;
                 break;

src/test/multisig_tests.cpp

@@ -82,20 +82,20 @@ BOOST_AUTO_TEST_CASE(multisig_verify)
     keys.assign(1,key[0]);
     keys.push_back(key[1]);
     s = sign_multisig(a_and_b, keys, txTo[0], 0);
-    BOOST_CHECK(VerifyScript(s, a_and_b, flags, MutableTransactionSignatureChecker(txTo[0], 0), &err));
+    BOOST_CHECK(VerifyScript(s, a_and_b, flags, MutableTransactionSignatureChecker(&txTo[0], 0), &err));
     BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_OK, ScriptErrorString(err));
 
     for (int i = 0; i < 4; i++)
     {
         keys.assign(1,key[i]);
         s = sign_multisig(a_and_b, keys, txTo[0], 0);
-        BOOST_CHECK_MESSAGE(!VerifyScript(s, a_and_b, flags, MutableTransactionSignatureChecker(txTo[0], 0), &err), strprintf("a&b 1: %d", i));
+        BOOST_CHECK_MESSAGE(!VerifyScript(s, a_and_b, flags, MutableTransactionSignatureChecker(&txTo[0], 0), &err), strprintf("a&b 1: %d", i));
         BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_INVALID_STACK_OPERATION, ScriptErrorString(err));
 
         keys.assign(1,key[1]);
         keys.push_back(key[i]);
         s = sign_multisig(a_and_b, keys, txTo[0], 0);
-        BOOST_CHECK_MESSAGE(!VerifyScript(s, a_and_b, flags, MutableTransactionSignatureChecker(txTo[0], 0), &err), strprintf("a&b 2: %d", i));
+        BOOST_CHECK_MESSAGE(!VerifyScript(s, a_and_b, flags, MutableTransactionSignatureChecker(&txTo[0], 0), &err), strprintf("a&b 2: %d", i));
         BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_EVAL_FALSE, ScriptErrorString(err));
     }
 
@@ -106,18 +106,18 @@ BOOST_AUTO_TEST_CASE(multisig_verify)
         s = sign_multisig(a_or_b, keys, txTo[1], 0);
         if (i == 0 || i == 1)
         {
-            BOOST_CHECK_MESSAGE(VerifyScript(s, a_or_b, flags, MutableTransactionSignatureChecker(txTo[1], 0), &err), strprintf("a|b: %d", i));
+            BOOST_CHECK_MESSAGE(VerifyScript(s, a_or_b, flags, MutableTransactionSignatureChecker(&txTo[1], 0), &err), strprintf("a|b: %d", i));
             BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_OK, ScriptErrorString(err));
         }
         else
         {
-            BOOST_CHECK_MESSAGE(!VerifyScript(s, a_or_b, flags, MutableTransactionSignatureChecker(txTo[1], 0), &err), strprintf("a|b: %d", i));
+            BOOST_CHECK_MESSAGE(!VerifyScript(s, a_or_b, flags, MutableTransactionSignatureChecker(&txTo[1], 0), &err), strprintf("a|b: %d", i));
             BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_EVAL_FALSE, ScriptErrorString(err));
         }
     }
     s.clear();
     s << OP_0 << OP_1;
-    BOOST_CHECK(!VerifyScript(s, a_or_b, flags, MutableTransactionSignatureChecker(txTo[1], 0), &err));
+    BOOST_CHECK(!VerifyScript(s, a_or_b, flags, MutableTransactionSignatureChecker(&txTo[1], 0), &err));
     BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_SIG_DER, ScriptErrorString(err));
 
 
@@ -129,12 +129,12 @@ BOOST_AUTO_TEST_CASE(multisig_verify)
             s = sign_multisig(escrow, keys, txTo[2], 0);
             if (i < j && i < 3 && j < 3)
             {
-                BOOST_CHECK_MESSAGE(VerifyScript(s, escrow, flags, MutableTransactionSignatureChecker(txTo[2], 0), &err), strprintf("escrow 1: %d %d", i, j));
+                BOOST_CHECK_MESSAGE(VerifyScript(s, escrow, flags, MutableTransactionSignatureChecker(&txTo[2], 0), &err), strprintf("escrow 1: %d %d", i, j));
                 BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_OK, ScriptErrorString(err));
             }
             else
             {
-                BOOST_CHECK_MESSAGE(!VerifyScript(s, escrow, flags, MutableTransactionSignatureChecker(txTo[2], 0), &err), strprintf("escrow 2: %d %d", i, j));
+                BOOST_CHECK_MESSAGE(!VerifyScript(s, escrow, flags, MutableTransactionSignatureChecker(&txTo[2], 0), &err), strprintf("escrow 2: %d %d", i, j));
                 BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_EVAL_FALSE, ScriptErrorString(err));
             }
         }

src/test/script_P2SH_tests.cpp

@@ -43,7 +43,7 @@ Verify(const CScript& scriptSig, const CScript& scriptPubKey, bool fStrict, Scri
     txTo.vin[0].scriptSig = scriptSig;
     txTo.vout[0].nValue = 1;
 
-    return VerifyScript(scriptSig, scriptPubKey, fStrict ? SCRIPT_VERIFY_P2SH : SCRIPT_VERIFY_NONE, MutableTransactionSignatureChecker(txTo, 0), &err);
+    return VerifyScript(scriptSig, scriptPubKey, fStrict ? SCRIPT_VERIFY_P2SH : SCRIPT_VERIFY_NONE, MutableTransactionSignatureChecker(&txTo, 0), &err);
 }
 
 

src/test/script_tests.cpp

@@ -93,7 +93,7 @@ void DoTest(const CScript& scriptPubKey, const CScript& scriptSig, int flags, bo
     ScriptError err;
     CMutableTransaction tx = BuildSpendingTransaction(scriptSig, BuildCreditingTransaction(scriptPubKey));
     CMutableTransaction tx2 = tx;
-    BOOST_CHECK_MESSAGE(VerifyScript(scriptSig, scriptPubKey, flags, MutableTransactionSignatureChecker(tx, 0), &err) == expect, message);
+    BOOST_CHECK_MESSAGE(VerifyScript(scriptSig, scriptPubKey, flags, MutableTransactionSignatureChecker(&tx, 0), &err) == expect, message);
     BOOST_CHECK_MESSAGE(expect == (err == SCRIPT_ERR_OK), std::string(ScriptErrorString(err)) + ": " + message);
 #if defined(HAVE_CONSENSUS_LIB)
     CDataStream stream(SER_NETWORK, PROTOCOL_VERSION);
@@ -682,18 +682,18 @@ BOOST_AUTO_TEST_CASE(script_CHECKMULTISIG12)
     CMutableTransaction txTo12 = BuildSpendingTransaction(CScript(), txFrom12);
 
     CScript goodsig1 = sign_multisig(scriptPubKey12, key1, txTo12);
-    BOOST_CHECK(VerifyScript(goodsig1, scriptPubKey12, flags, MutableTransactionSignatureChecker(txTo12, 0), &err));
+    BOOST_CHECK(VerifyScript(goodsig1, scriptPubKey12, flags, MutableTransactionSignatureChecker(&txTo12, 0), &err));
     BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_OK, ScriptErrorString(err));
     txTo12.vout[0].nValue = 2;
-    BOOST_CHECK(!VerifyScript(goodsig1, scriptPubKey12, flags, MutableTransactionSignatureChecker(txTo12, 0), &err));
+    BOOST_CHECK(!VerifyScript(goodsig1, scriptPubKey12, flags, MutableTransactionSignatureChecker(&txTo12, 0), &err));
     BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_EVAL_FALSE, ScriptErrorString(err));
 
     CScript goodsig2 = sign_multisig(scriptPubKey12, key2, txTo12);
-    BOOST_CHECK(VerifyScript(goodsig2, scriptPubKey12, flags, MutableTransactionSignatureChecker(txTo12, 0), &err));
+    BOOST_CHECK(VerifyScript(goodsig2, scriptPubKey12, flags, MutableTransactionSignatureChecker(&txTo12, 0), &err));
     BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_OK, ScriptErrorString(err));
 
     CScript badsig1 = sign_multisig(scriptPubKey12, key3, txTo12);
-    BOOST_CHECK(!VerifyScript(badsig1, scriptPubKey12, flags, MutableTransactionSignatureChecker(txTo12, 0), &err));
+    BOOST_CHECK(!VerifyScript(badsig1, scriptPubKey12, flags, MutableTransactionSignatureChecker(&txTo12, 0), &err));
     BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_EVAL_FALSE, ScriptErrorString(err));
 }
 
@@ -715,54 +715,54 @@ BOOST_AUTO_TEST_CASE(script_CHECKMULTISIG23)
     std::vector<CKey> keys;
     keys.push_back(key1); keys.push_back(key2);
     CScript goodsig1 = sign_multisig(scriptPubKey23, keys, txTo23);
-    BOOST_CHECK(VerifyScript(goodsig1, scriptPubKey23, flags, MutableTransactionSignatureChecker(txTo23, 0), &err));
+    BOOST_CHECK(VerifyScript(goodsig1, scriptPubKey23, flags, MutableTransactionSignatureChecker(&txTo23, 0), &err));
     BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_OK, ScriptErrorString(err));
 
     keys.clear();
     keys.push_back(key1); keys.push_back(key3);
     CScript goodsig2 = sign_multisig(scriptPubKey23, keys, txTo23);
-    BOOST_CHECK(VerifyScript(goodsig2, scriptPubKey23, flags, MutableTransactionSignatureChecker(txTo23, 0), &err));
+    BOOST_CHECK(VerifyScript(goodsig2, scriptPubKey23, flags, MutableTransactionSignatureChecker(&txTo23, 0), &err));
     BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_OK, ScriptErrorString(err));
 
     keys.clear();
     keys.push_back(key2); keys.push_back(key3);
     CScript goodsig3 = sign_multisig(scriptPubKey23, keys, txTo23);
-    BOOST_CHECK(VerifyScript(goodsig3, scriptPubKey23, flags, MutableTransactionSignatureChecker(txTo23, 0), &err));
+    BOOST_CHECK(VerifyScript(goodsig3, scriptPubKey23, flags, MutableTransactionSignatureChecker(&txTo23, 0), &err));
     BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_OK, ScriptErrorString(err));
 
     keys.clear();
     keys.push_back(key2); keys.push_back(key2); // Can't re-use sig
     CScript badsig1 = sign_multisig(scriptPubKey23, keys, txTo23);
-    BOOST_CHECK(!VerifyScript(badsig1, scriptPubKey23, flags, MutableTransactionSignatureChecker(txTo23, 0), &err));
+    BOOST_CHECK(!VerifyScript(badsig1, scriptPubKey23, flags, MutableTransactionSignatureChecker(&txTo23, 0), &err));
     BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_EVAL_FALSE, ScriptErrorString(err));
 
     keys.clear();
     keys.push_back(key2); keys.push_back(key1); // sigs must be in correct order
     CScript badsig2 = sign_multisig(scriptPubKey23, keys, txTo23);
-    BOOST_CHECK(!VerifyScript(badsig2, scriptPubKey23, flags, MutableTransactionSignatureChecker(txTo23, 0), &err));
+    BOOST_CHECK(!VerifyScript(badsig2, scriptPubKey23, flags, MutableTransactionSignatureChecker(&txTo23, 0), &err));
     BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_EVAL_FALSE, ScriptErrorString(err));
 
     keys.clear();
     keys.push_back(key3); keys.push_back(key2); // sigs must be in correct order
     CScript badsig3 = sign_multisig(scriptPubKey23, keys, txTo23);
-    BOOST_CHECK(!VerifyScript(badsig3, scriptPubKey23, flags, MutableTransactionSignatureChecker(txTo23, 0), &err));
+    BOOST_CHECK(!VerifyScript(badsig3, scriptPubKey23, flags, MutableTransactionSignatureChecker(&txTo23, 0), &err));
     BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_EVAL_FALSE, ScriptErrorString(err));
 
     keys.clear();
     keys.push_back(key4); keys.push_back(key2); // sigs must match pubkeys
     CScript badsig4 = sign_multisig(scriptPubKey23, keys, txTo23);
-    BOOST_CHECK(!VerifyScript(badsig4, scriptPubKey23, flags, MutableTransactionSignatureChecker(txTo23, 0), &err));
+    BOOST_CHECK(!VerifyScript(badsig4, scriptPubKey23, flags, MutableTransactionSignatureChecker(&txTo23, 0), &err));
     BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_EVAL_FALSE, ScriptErrorString(err));
 
     keys.clear();
     keys.push_back(key1); keys.push_back(key4); // sigs must match pubkeys
     CScript badsig5 = sign_multisig(scriptPubKey23, keys, txTo23);
-    BOOST_CHECK(!VerifyScript(badsig5, scriptPubKey23, flags, MutableTransactionSignatureChecker(txTo23, 0), &err));
+    BOOST_CHECK(!VerifyScript(badsig5, scriptPubKey23, flags, MutableTransactionSignatureChecker(&txTo23, 0), &err));
     BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_EVAL_FALSE, ScriptErrorString(err));
 
     keys.clear(); // Must have signatures
     CScript badsig6 = sign_multisig(scriptPubKey23, keys, txTo23);
-    BOOST_CHECK(!VerifyScript(badsig6, scriptPubKey23, flags, MutableTransactionSignatureChecker(txTo23, 0), &err));
+    BOOST_CHECK(!VerifyScript(badsig6, scriptPubKey23, flags, MutableTransactionSignatureChecker(&txTo23, 0), &err));
     BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_INVALID_STACK_OPERATION, ScriptErrorString(err));
 }    
 

src/test/transaction_tests.cpp

@@ -145,7 +145,7 @@ BOOST_AUTO_TEST_CASE(tx_valid)
 
                 unsigned int verify_flags = ParseScriptFlags(test[2].get_str());
                 BOOST_CHECK_MESSAGE(VerifyScript(tx.vin[i].scriptSig, mapprevOutScriptPubKeys[tx.vin[i].prevout],
-                                                 verify_flags, TransactionSignatureChecker(tx, i), &err),
+                                                 verify_flags, TransactionSignatureChecker(&tx, i), &err),
                                     strTest);
                 BOOST_CHECK_MESSAGE(err == SCRIPT_ERR_OK, ScriptErrorString(err));
             }
@@ -220,7 +220,7 @@ BOOST_AUTO_TEST_CASE(tx_invalid)
 
                 unsigned int verify_flags = ParseScriptFlags(test[2].get_str());
                 fValid = VerifyScript(tx.vin[i].scriptSig, mapprevOutScriptPubKeys[tx.vin[i].prevout],
-                                      verify_flags, TransactionSignatureChecker(tx, i), &err);
+                                      verify_flags, TransactionSignatureChecker(&tx, i), &err);
             }
             BOOST_CHECK_MESSAGE(!fValid, strTest);
             BOOST_CHECK_MESSAGE(err != SCRIPT_ERR_OK, ScriptErrorString(err));