From 67d4d891ef847a8979fce36a37073ff4d74316b6 Mon Sep 17 00:00:00 2001
From: Anna Shaleva <shaleva.ann@nspcc.ru>
Date: Wed, 26 Apr 2023 14:10:12 +0300
Subject: [PATCH] core: prevent direct access to Notary contract if not active

Otherwise it will cause panic, which isn't expected behaviour.

Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
---
 pkg/core/blockchain.go              | 14 ++++++++++----
 pkg/core/blockchain_neotest_test.go | 20 +++++++++++---------
 2 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/pkg/core/blockchain.go b/pkg/core/blockchain.go
index 064453ca5..67c6f8b9e 100644
--- a/pkg/core/blockchain.go
+++ b/pkg/core/blockchain.go
@@ -2567,7 +2567,10 @@ func (bc *Blockchain) verifyTxAttributes(d *dao.Simple, tx *transaction.Transact
 			nvb := tx.Attributes[i].Value.(*transaction.NotValidBefore).Height
 			curHeight := bc.BlockHeight()
 			if isPartialTx {
-				maxNVBDelta := bc.contracts.Notary.GetMaxNotValidBeforeDelta(bc.dao)
+				maxNVBDelta, err := bc.GetMaxNotValidBeforeDelta()
+				if err != nil {
+					return fmt.Errorf("%w: failed to retrieve MaxNotValidBeforeDelta value from native Notary contract: %v", ErrInvalidAttribute, err)
+				}
 				if curHeight+maxNVBDelta < nvb {
 					return fmt.Errorf("%w: NotValidBefore (%d) bigger than MaxNVBDelta (%d) allows at height %d", ErrInvalidAttribute, nvb, maxNVBDelta, curHeight)
 				}
@@ -2972,11 +2975,14 @@ func (bc *Blockchain) GetMaxVerificationGAS() int64 {
 }
 
 // GetMaxNotValidBeforeDelta returns maximum NotValidBeforeDelta Notary limit.
-func (bc *Blockchain) GetMaxNotValidBeforeDelta() uint32 {
+func (bc *Blockchain) GetMaxNotValidBeforeDelta() (uint32, error) {
 	if !bc.config.P2PSigExtensions {
-		panic("disallowed call to Notary")
+		panic("disallowed call to Notary") // critical error, thus panic.
 	}
-	return bc.contracts.Notary.GetMaxNotValidBeforeDelta(bc.dao)
+	if bc.contracts.Notary.Metadata().UpdateHistory[0] > bc.BlockHeight() {
+		return 0, fmt.Errorf("native Notary is active starting from %d", bc.contracts.Notary.Metadata().UpdateHistory[0])
+	}
+	return bc.contracts.Notary.GetMaxNotValidBeforeDelta(bc.dao), nil
 }
 
 // GetStoragePrice returns current storage price.
diff --git a/pkg/core/blockchain_neotest_test.go b/pkg/core/blockchain_neotest_test.go
index f5e2edcbf..3e64fadd5 100644
--- a/pkg/core/blockchain_neotest_test.go
+++ b/pkg/core/blockchain_neotest_test.go
@@ -347,10 +347,9 @@ func TestBlockchain_InitializeNativeCacheWrtNativeActivations(t *testing.T) {
 	e = neotest.NewExecutor(t, bc, validators, committee)
 	h := e.Chain.BlockHeight()
 
-	// Notary isn't initialized yet, so accessing Notary cache should panic.
-	require.Panics(t, func() {
-		_ = e.Chain.GetMaxNotValidBeforeDelta()
-	})
+	// Notary isn't initialized yet, so accessing Notary cache should return error.
+	_, err = e.Chain.GetMaxNotValidBeforeDelta()
+	require.Error(t, err)
 
 	// Ensure Notary will be properly initialized and accessing Notary cache works
 	// as expected.
@@ -359,9 +358,8 @@ func TestBlockchain_InitializeNativeCacheWrtNativeActivations(t *testing.T) {
 			e.AddNewBlock(t)
 		}, h+uint32(i)+1)
 	}
-	require.NotPanics(t, func() {
-		_ = e.Chain.GetMaxNotValidBeforeDelta()
-	})
+	_, err = e.Chain.GetMaxNotValidBeforeDelta()
+	require.NoError(t, err)
 }
 
 func TestBlockchain_AddHeaders(t *testing.T) {
@@ -1949,11 +1947,15 @@ func TestBlockchain_VerifyTx(t *testing.T) {
 			require.Error(t, bc.PoolTxWithData(tx, 5, mp, bc, verificationF))
 		})
 		t.Run("bad NVB: too big", func(t *testing.T) {
-			tx := getPartiallyFilledTx(bc.BlockHeight()+bc.GetMaxNotValidBeforeDelta()+1, bc.BlockHeight()+1)
+			maxNVB, err := bc.GetMaxNotValidBeforeDelta()
+			require.NoError(t, err)
+			tx := getPartiallyFilledTx(bc.BlockHeight()+maxNVB+1, bc.BlockHeight()+1)
 			require.True(t, errors.Is(bc.PoolTxWithData(tx, 5, mp, bc, verificationF), core.ErrInvalidAttribute))
 		})
 		t.Run("bad ValidUntilBlock: too small", func(t *testing.T) {
-			tx := getPartiallyFilledTx(bc.BlockHeight(), bc.BlockHeight()+bc.GetMaxNotValidBeforeDelta()+1)
+			maxNVB, err := bc.GetMaxNotValidBeforeDelta()
+			require.NoError(t, err)
+			tx := getPartiallyFilledTx(bc.BlockHeight(), bc.BlockHeight()+maxNVB+1)
 			require.True(t, errors.Is(bc.PoolTxWithData(tx, 5, mp, bc, verificationF), core.ErrInvalidAttribute))
 		})
 		t.Run("good", func(t *testing.T) {