[Consensus] Guard P2CS change with contextual flag g_IsV6Active

random-zebra · random-zebra · commit c8502bf75389 · 2021-05-06T14:25:58.000+02:00
diff --git a/src/script/interpreter.cpp b/src/script/interpreter.cpp
@@ -962,22 +962,24 @@ bool EvalScript(std::vector<std::vector<unsigned char> >& stack, const CScript&
 
                 case OP_CHECKCOLDSTAKEVERIFY:
                 {
-                    // the stack can contain only <sig> <pk> <pkh> at this point
-                    if ((int)stack.size() != 3) {
-                        return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
-                    }
-                    // check pubkey/signature encoding
-                    valtype& vchSig    = stacktop(-3);
-                    valtype& vchPubKey = stacktop(-2);
-                    if (!CheckSignatureEncoding(vchSig, flags, serror) ||
-                            !CheckPubKeyEncoding(vchPubKey, flags, serror)) {
-                        // serror is set
-                        return false;
-                    }
-                    // check hash size
-                    valtype& vchPubKeyHash = stacktop(-1);
-                    if ((int)vchPubKeyHash.size() != 20) {
-                        return set_error(serror, SCRIPT_ERR_SCRIPT_SIZE);
+                    if (g_IsV6Active) {
+                        // the stack can contain only <sig> <pk> <pkh> at this point
+                        if ((int)stack.size() != 3) {
+                            return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+                        }
+                        // check pubkey/signature encoding
+                        valtype& vchSig    = stacktop(-3);
+                        valtype& vchPubKey = stacktop(-2);
+                        if (!CheckSignatureEncoding(vchSig, flags, serror) ||
+                                !CheckPubKeyEncoding(vchPubKey, flags, serror)) {
+                            // serror is set
+                            return false;
+                        }
+                        // check hash size
+                        valtype& vchPubKeyHash = stacktop(-1);
+                        if ((int)vchPubKeyHash.size() != 20) {
+                            return set_error(serror, SCRIPT_ERR_SCRIPT_SIZE);
+                        }
                     }
                     if(!checker.CheckColdStake(script)) {
                         return set_error(serror, SCRIPT_ERR_CHECKCOLDSTAKEVERIFY);
diff --git a/src/script/script.cpp b/src/script/script.cpp
@@ -8,6 +8,8 @@
 #include "tinyformat.h"
 #include "utilstrencodings.h"
 
+#include <atomic>
+
 
 const char* GetOpName(opcodetype opcode)
 {
@@ -223,18 +225,22 @@ bool CScript::IsPayToScriptHash() const
             (*this)[22] == OP_EQUAL);
 }
 
+// contextual flag to guard the new rules for P2CS.
+// can be removed once v6 enforcement is activated.
+std::atomic<bool> g_IsV6Active{false};
+
 bool CScript::IsPayToColdStaking() const
 {
     return (this->size() == 51 &&
-            (*this)[0] == OP_DUP &&
-            (*this)[1] == OP_HASH160 &&
+            (!g_IsV6Active || (*this)[0] == OP_DUP) &&
+            (!g_IsV6Active || (*this)[1] == OP_HASH160) &&
             (*this)[2] == OP_ROT &&
-            (*this)[3] == OP_IF &&
+            (!g_IsV6Active || (*this)[3] == OP_IF) &&
             (*this)[4] == OP_CHECKCOLDSTAKEVERIFY &&
             (*this)[5] == 0x14 &&
-            (*this)[26] == OP_ELSE &&
+            (!g_IsV6Active || (*this)[26] == OP_ELSE) &&
             (*this)[27] == 0x14 &&
-            (*this)[48] == OP_ENDIF &&
+            (!g_IsV6Active || (*this)[48] == OP_ENDIF) &&
             (*this)[49] == OP_EQUALVERIFY &&
             (*this)[50] == OP_CHECKSIG);
 }
diff --git a/src/script/script.h b/src/script/script.h
@@ -661,4 +661,8 @@ class CScript : public CScriptBase
     size_t DynamicMemoryUsage() const;
 };
 
+// contextual flag to guard the new rules for P2CS.
+// can be removed once v6 enforcement is activated.
+extern std::atomic<bool> g_IsV6Active;
+
 #endif // BITCOIN_SCRIPT_SCRIPT_H
diff --git a/src/test/script_P2CS_tests.cpp b/src/test/script_P2CS_tests.cpp
@@ -232,9 +232,10 @@ static void setupWallet(CWallet& wallet)
     wallet.SetupSPKM(false);
 }
 
-/* !TODO: check before/after v6 enforcement
 BOOST_AUTO_TEST_CASE(fake_script_test)
 {
+    BOOST_ASSERT(!g_IsV6Active);
+
     CWallet& wallet = *pwalletMain;
     LOCK(wallet.cs_wallet);
     setupWallet(wallet);
@@ -250,17 +251,21 @@ BOOST_AUTO_TEST_CASE(fake_script_test)
     const CScript& scriptP2CS = GetFakeLockingScript(stakerId, ownerId);
 
     // Create prev transaction:
+    // It has two outputs. The first one is spent before v6.
+    // The second one is tested after v6 enforcement.
     CMutableTransaction txFrom;
-    txFrom.vout.resize(1);
-    txFrom.vout[0].nValue = amtIn;
-    txFrom.vout[0].scriptPubKey = scriptP2CS;
+    txFrom.vout.resize(2);
+    for (size_t i = 0; i < 2; i++) {
+        txFrom.vout[i].nValue = amtIn;
+        txFrom.vout[i].scriptPubKey = scriptP2CS;
+    }
 
     // passes IsPayToColdStaking
     BOOST_CHECK(scriptP2CS.IsPayToColdStaking());
 
     // the output amount is credited to the owner wallet
     wallet.AddToWallet({&wallet, MakeTransactionRef(CTransaction(txFrom))});
-    BOOST_CHECK_EQUAL(wallet.GetWalletTx(txFrom.GetHash())->GetAvailableCredit(false, ISMINE_SPENDABLE_TRANSPARENT), amtIn);
+    BOOST_CHECK_EQUAL(wallet.GetWalletTx(txFrom.GetHash())->GetAvailableCredit(false, ISMINE_SPENDABLE_TRANSPARENT), 2 * amtIn);
 
     // create spend tx
     CMutableTransaction tx;
@@ -283,8 +288,16 @@ BOOST_AUTO_TEST_CASE(fake_script_test)
         BOOST_ERROR(strprintf("P2CS verification failed: %s", ScriptErrorString(err)));
     }
     wallet.AddToWallet({&wallet, MakeTransactionRef(CTransaction(tx))});
+    BOOST_CHECK_EQUAL(wallet.GetWalletTx(txFrom.GetHash())->GetAvailableCredit(false, ISMINE_SPENDABLE_TRANSPARENT), amtIn);
+
+    // Now let's activate v6
+    g_IsV6Active = true;
+
+    // it does NOT pass IsPayToColdStaking
+    BOOST_CHECK_MESSAGE(!scriptP2CS.IsPayToColdStaking(), "Fake script passes as P2CS");
+
+    // the output amount is NOT credited to the owner wallet
     BOOST_CHECK_EQUAL(wallet.GetWalletTx(txFrom.GetHash())->GetAvailableCredit(false, ISMINE_SPENDABLE_TRANSPARENT), 0);
 }
-*/
 
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/validation.cpp b/src/validation.cpp
@@ -1922,6 +1922,7 @@ void static UpdateTip(CBlockIndex* pindexNew)
 {
     AssertLockHeld(cs_main);
     chainActive.SetTip(pindexNew);
+    g_IsV6Active = Params().GetConsensus().NetworkUpgradeActive(pindexNew->nHeight, Consensus::UPGRADE_V6_0);
 
     // New best block
     mempool.AddTransactionsUpdated(1);
@@ -3660,6 +3661,9 @@ bool LoadChainTip(const CChainParams& chainparams)
 
     const CBlockIndex* pChainTip = chainActive.Tip();
 
+    // initial global flag update
+    g_IsV6Active = Params().GetConsensus().NetworkUpgradeActive(pChainTip->nHeight, Consensus::UPGRADE_V5_0);
+
     LogPrintf("Loaded best chain: hashBestChain=%s height=%d date=%s progress=%f\n",
             pChainTip->GetBlockHash().GetHex(), pChainTip->nHeight,
             FormatISO8601DateTime(pChainTip->GetBlockTime()),
