Get rid of inaccurate ScriptSigArgsExpected

sipa · MarcoFalke · commit 5d743099b5fe · 2016-02-01T15:28:25.000+01:00
(cherry picked from commit 52b29dc)
diff --git a/src/policy/policy.cpp b/src/policy/policy.cpp
@@ -132,45 +132,20 @@ bool AreInputsStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs)
         const CScript& prevScript = prev.scriptPubKey;
         if (!Solver(prevScript, whichType, vSolutions))
             return false;
-        int nArgsExpected = ScriptSigArgsExpected(whichType, vSolutions);
-        if (nArgsExpected < 0)
-            return false;
-
-        // Transactions with extra stuff in their scriptSigs are
-        // non-standard. Note that this EvalScript() call will
-        // be quick, because if there are any operations
-        // beside "push data" in the scriptSig
-        // IsStandardTx() will have already returned false
-        // and this method isn't called.
-        std::vector<std::vector<unsigned char> > stack;
-        if (!EvalScript(stack, tx.vin[i].scriptSig, SCRIPT_VERIFY_NONE, BaseSignatureChecker()))
-            return false;
 
         if (whichType == TX_SCRIPTHASH)
         {
+            std::vector<std::vector<unsigned char> > stack;
+            // convert the scriptSig into a stack, so we can inspect the redeemScript
+            if (!EvalScript(stack, tx.vin[i].scriptSig, SCRIPT_VERIFY_NONE, BaseSignatureChecker(), 0))
+                return false;
             if (stack.empty())
                 return false;
             CScript subscript(stack.back().begin(), stack.back().end());
-            std::vector<std::vector<unsigned char> > vSolutions2;
-            txnouttype whichType2;
-            if (Solver(subscript, whichType2, vSolutions2))
-            {
-                int tmpExpected = ScriptSigArgsExpected(whichType2, vSolutions2);
-                if (tmpExpected < 0)
-                    return false;
-                nArgsExpected += tmpExpected;
-            }
-            else
-            {
-                // Any other Script with less than 15 sigops OK:
-                unsigned int sigops = subscript.GetSigOpCount(true);
-                // ... extra data left on the stack after execution is OK, too:
-                return (sigops <= MAX_P2SH_SIGOPS);
+            if (subscript.GetSigOpCount(true) > MAX_P2SH_SIGOPS) {
+                return false;
             }
         }
-
-        if (stack.size() != (unsigned int)nArgsExpected)
-            return false;
     }
 
     return true;
diff --git a/src/script/standard.cpp b/src/script/standard.cpp
@@ -161,27 +161,6 @@ bool Solver(const CScript& scriptPubKey, txnouttype& typeRet, vector<vector<unsi
     return false;
 }
 
-int ScriptSigArgsExpected(txnouttype t, const std::vector<std::vector<unsigned char> >& vSolutions)
-{
-    switch (t)
-    {
-    case TX_NONSTANDARD:
-    case TX_NULL_DATA:
-        return -1;
-    case TX_PUBKEY:
-        return 1;
-    case TX_PUBKEYHASH:
-        return 2;
-    case TX_MULTISIG:
-        if (vSolutions.size() < 1 || vSolutions[0].size() < 1)
-            return -1;
-        return vSolutions[0][0] + 1;
-    case TX_SCRIPTHASH:
-        return 1; // doesn't include args needed by the script
-    }
-    return -1;
-}
-
 bool ExtractDestination(const CScript& scriptPubKey, CTxDestination& addressRet)
 {
     vector<valtype> vSolutions;
diff --git a/src/script/standard.h b/src/script/standard.h
@@ -71,7 +71,6 @@ typedef boost::variant<CNoDestination, CKeyID, CScriptID> CTxDestination;
 const char* GetTxnOutputType(txnouttype t);
 
 bool Solver(const CScript& scriptPubKey, txnouttype& typeRet, std::vector<std::vector<unsigned char> >& vSolutionsRet);
-int ScriptSigArgsExpected(txnouttype t, const std::vector<std::vector<unsigned char> >& vSolutions);
 bool ExtractDestination(const CScript& scriptPubKey, CTxDestination& addressRet);
 bool ExtractDestinations(const CScript& scriptPubKey, txnouttype& typeRet, std::vector<CTxDestination>& addressRet, int& nRequiredRet);
 
diff --git a/src/test/script_P2SH_tests.cpp b/src/test/script_P2SH_tests.cpp
@@ -346,15 +346,6 @@ BOOST_AUTO_TEST_CASE(AreInputsStandard)
     // 22 P2SH sigops for all inputs (1 for vin[0], 6 for vin[3], 15 for vin[4]
     BOOST_CHECK_EQUAL(GetP2SHSigOpCount(txTo, coins), 22U);
 
-    // Make sure adding crap to the scriptSigs makes them non-standard:
-    for (int i = 0; i < 3; i++)
-    {
-        CScript t = txTo.vin[i].scriptSig;
-        txTo.vin[i].scriptSig = (CScript() << 11) + t;
-        BOOST_CHECK(!::AreInputsStandard(txTo, coins));
-        txTo.vin[i].scriptSig = t;
-    }
-
     CMutableTransaction txToNonStd1;
     txToNonStd1.vout.resize(1);
     txToNonStd1.vout[0].scriptPubKey = GetScriptForDestination(key[1].GetPubKey().GetID());
diff --git a/src/test/transaction_tests.cpp b/src/test/transaction_tests.cpp
@@ -310,14 +310,6 @@ BOOST_AUTO_TEST_CASE(test_Get)
 
     BOOST_CHECK(AreInputsStandard(t1, coins));
     BOOST_CHECK_EQUAL(coins.GetValueIn(t1), (50+21+22)*CENT);
-
-    // Adding extra junk to the scriptSig should make it non-standard:
-    t1.vin[0].scriptSig << OP_11;
-    BOOST_CHECK(!AreInputsStandard(t1, coins));
-
-    // ... as should not having enough:
-    t1.vin[0].scriptSig = CScript();
-    BOOST_CHECK(!AreInputsStandard(t1, coins));
 }
 
 BOOST_AUTO_TEST_CASE(test_IsStandard)
