From 2b11e99225850bd9f51e50a1e26cf11dfc89b632 Mon Sep 17 00:00:00 2001
From: Anna Shaleva <shaleva.ann@nspcc.ru>
Date: Wed, 30 Sep 2020 13:20:40 +0300
Subject: [PATCH] core: fix CalculateNetworkFee for signature contracts

First PUSHDATA1 is from invocation script, the second PUSHDATA1 is
from verification script. E.g.:

Invocation script:

INDEX    OPCODE       PARAMETER
0        PUSHDATA1    035913b9588da23a5c3ce14b2886a6b8ebb6a0eb92bdaa948510dfb5ae5194d6cb    <<
35       PUSHNULL
36       SYSCALL      Neo.Crypto.VerifyWithECDsaSecp256r1 (95440d78)

Verification script:

INDEX    OPCODE       PARAMETER
0        PUSHDATA1    3930fe5a9b44682f37741955df4a5f2585ed5aa438fa6e17ae51083673b1d64253e5a859c0cf168be67971e53a23c1c40582777d94a8e391db23ff613849627d    <<
---
 pkg/core/blockchain_test.go | 49 ++++++++++++++++++++++++++++++++-----
 pkg/core/util.go            |  2 +-
 2 files changed, 44 insertions(+), 7 deletions(-)

diff --git a/pkg/core/blockchain_test.go b/pkg/core/blockchain_test.go
index 2347f03cc..78de1c9f9 100644
--- a/pkg/core/blockchain_test.go
+++ b/pkg/core/blockchain_test.go
@@ -215,7 +215,7 @@ func TestVerifyTx(t *testing.T) {
 	bc := newTestChain(t)
 	defer bc.Close()
 
-	accs := make([]*wallet.Account, 4)
+	accs := make([]*wallet.Account, 5)
 	for i := range accs {
 		var err error
 		accs[i], err = wallet.NewAccount()
@@ -291,11 +291,48 @@ func TestVerifyTx(t *testing.T) {
 		require.NoError(t, accs[0].SignTx(tx))
 		checkErr(t, ErrTxTooBig, tx)
 	})
-	t.Run("SmallNetworkFee", func(t *testing.T) {
-		tx := bc.newTestTx(h, testScript)
-		tx.NetworkFee = 1
-		require.NoError(t, accs[0].SignTx(tx))
-		checkErr(t, ErrTxSmallNetworkFee, tx)
+	t.Run("NetworkFee", func(t *testing.T) {
+		t.Run("SmallNetworkFee", func(t *testing.T) {
+			tx := bc.newTestTx(h, testScript)
+			tx.NetworkFee = 1
+			require.NoError(t, accs[0].SignTx(tx))
+			checkErr(t, ErrTxSmallNetworkFee, tx)
+		})
+		t.Run("CalculateNetworkFee, signature script", func(t *testing.T) {
+			tx := bc.newTestTx(h, testScript)
+			expectedSize := io.GetVarSize(tx)
+			verificationNetFee, calculatedScriptSize := CalculateNetworkFee(accs[0].Contract.Script)
+			expectedSize += calculatedScriptSize
+			expectedNetFee := verificationNetFee + int64(expectedSize)*bc.FeePerByte()
+			tx.NetworkFee = expectedNetFee
+			require.NoError(t, accs[0].SignTx(tx))
+			actualSize := io.GetVarSize(tx)
+			require.Equal(t, expectedSize, actualSize)
+			interopCtx := bc.newInteropContext(trigger.Verification, bc.dao, nil, tx)
+			gasConsumed, err := bc.verifyHashAgainstScript(h, &tx.Scripts[0], interopCtx, -1)
+			require.NoError(t, err)
+			require.Equal(t, verificationNetFee, gasConsumed)
+			require.Equal(t, expectedNetFee, bc.FeePerByte()*int64(actualSize)+gasConsumed)
+		})
+		t.Run("CalculateNetworkFee, multisignature script", func(t *testing.T) {
+			multisigAcc := accs[4]
+			pKeys := keys.PublicKeys{multisigAcc.PrivateKey().PublicKey()}
+			require.NoError(t, multisigAcc.ConvertMultisig(1, pKeys))
+			multisigHash := hash.Hash160(multisigAcc.Contract.Script)
+			tx := bc.newTestTx(multisigHash, testScript)
+			verificationNetFee, calculatedScriptSize := CalculateNetworkFee(multisigAcc.Contract.Script)
+			expectedSize := io.GetVarSize(tx) + calculatedScriptSize
+			expectedNetFee := verificationNetFee + int64(expectedSize)*bc.FeePerByte()
+			tx.NetworkFee = expectedNetFee
+			require.NoError(t, multisigAcc.SignTx(tx))
+			actualSize := io.GetVarSize(tx)
+			require.Equal(t, expectedSize, actualSize)
+			interopCtx := bc.newInteropContext(trigger.Verification, bc.dao, nil, tx)
+			gasConsumed, err := bc.verifyHashAgainstScript(multisigHash, &tx.Scripts[0], interopCtx, -1)
+			require.NoError(t, err)
+			require.Equal(t, verificationNetFee, gasConsumed)
+			require.Equal(t, expectedNetFee, bc.FeePerByte()*int64(actualSize)+gasConsumed)
+		})
 	})
 	t.Run("Conflict", func(t *testing.T) {
 		balance := bc.GetUtilityTokenBalance(h).Int64()
diff --git a/pkg/core/util.go b/pkg/core/util.go
index 9ce81e47b..973c74c46 100644
--- a/pkg/core/util.go
+++ b/pkg/core/util.go
@@ -138,7 +138,7 @@ func CalculateNetworkFee(script []byte) (int64, int) {
 	)
 	if vm.IsSignatureContract(script) {
 		size += 67 + io.GetVarSize(script)
-		netFee += opcodePrice(opcode.PUSHDATA1, opcode.PUSHNULL) + crypto.ECDSAVerifyPrice
+		netFee += opcodePrice(opcode.PUSHDATA1, opcode.PUSHNULL, opcode.PUSHDATA1) + crypto.ECDSAVerifyPrice
 	} else if m, pubs, ok := vm.ParseMultiSigContract(script); ok {
 		n := len(pubs)
 		sizeInv := 66 * m