From 1c4c783c3a7e10cf54e35aa79d7ccfbfdbab4d25 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 11 Jan 2023 12:05:05 +0300
Subject: [PATCH] core: store magic in the DB version, fix #2847

---
 pkg/core/blockchain.go              |  7 ++++++-
 pkg/core/blockchain_neotest_test.go |  9 +++++++++
 pkg/core/dao/dao.go                 | 12 ++++++++++--
 3 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/pkg/core/blockchain.go b/pkg/core/blockchain.go
index 6ac36da8f..f80cecb6f 100644
--- a/pkg/core/blockchain.go
+++ b/pkg/core/blockchain.go
@@ -45,7 +45,7 @@ import (
 
 // Tuning parameters.
 const (
-	version = "0.2.7"
+	version = "0.2.8"
 
 	defaultInitialGAS                      = 52000000_00000000
 	defaultGCPeriod                        = 10000
@@ -381,6 +381,7 @@ func (bc *Blockchain) init() error {
 			P2PSigExtensions:           bc.config.P2PSigExtensions,
 			P2PStateExchangeExtensions: bc.config.P2PStateExchangeExtensions,
 			KeepOnlyLatestState:        bc.config.Ledger.KeepOnlyLatestState,
+			Magic:                      uint32(bc.config.Magic),
 			Value:                      version,
 		}
 		bc.dao.PutVersion(ver)
@@ -415,6 +416,10 @@ func (bc *Blockchain) init() error {
 		return fmt.Errorf("KeepOnlyLatestState setting mismatch (old=%v, new=%v)",
 			ver.KeepOnlyLatestState, bc.config.Ledger.KeepOnlyLatestState)
 	}
+	if ver.Magic != uint32(bc.config.Magic) {
+		return fmt.Errorf("protocol configuration Magic mismatch (old=%v, new=%v)",
+			ver.Magic, bc.config.Magic)
+	}
 	bc.dao.Version = ver
 	bc.persistent.Version = ver
 
diff --git a/pkg/core/blockchain_neotest_test.go b/pkg/core/blockchain_neotest_test.go
index cacfe126c..f71b8890b 100644
--- a/pkg/core/blockchain_neotest_test.go
+++ b/pkg/core/blockchain_neotest_test.go
@@ -141,6 +141,15 @@ func TestBlockchain_StartFromExistingDB(t *testing.T) {
 		require.Error(t, err)
 		require.True(t, strings.Contains(err.Error(), "KeepOnlyLatestState setting mismatch"), err)
 	})
+	t.Run("Magic mismatch", func(t *testing.T) {
+		ps = newPS(t)
+		_, _, _, err := chain.NewMultiWithCustomConfigAndStoreNoCheck(t, func(c *config.Blockchain) {
+			customConfig(c)
+			c.Magic = 100500
+		}, ps)
+		require.Error(t, err)
+		require.True(t, strings.Contains(err.Error(), "protocol configuration Magic mismatch"), err)
+	})
 	t.Run("corrupted headers", func(t *testing.T) {
 		ps = newPS(t)
 
diff --git a/pkg/core/dao/dao.go b/pkg/core/dao/dao.go
index 844490dd0..54a9cd85a 100644
--- a/pkg/core/dao/dao.go
+++ b/pkg/core/dao/dao.go
@@ -440,6 +440,7 @@ type Version struct {
 	P2PSigExtensions           bool
 	P2PStateExchangeExtensions bool
 	KeepOnlyLatestState        bool
+	Magic                      uint32
 	Value                      string
 }
 
@@ -464,7 +465,7 @@ func (v *Version) FromBytes(data []byte) error {
 		return nil
 	}
 
-	if len(data) != i+3 {
+	if len(data) < i+3 {
 		return errors.New("version is invalid")
 	}
 
@@ -474,6 +475,11 @@ func (v *Version) FromBytes(data []byte) error {
 	v.P2PSigExtensions = data[i+2]&p2pSigExtensionsBit != 0
 	v.P2PStateExchangeExtensions = data[i+2]&p2pStateExchangeExtensionsBit != 0
 	v.KeepOnlyLatestState = data[i+2]&keepOnlyLatestStateBit != 0
+
+	m := i + 3
+	if len(data) == m+4 {
+		v.Magic = binary.LittleEndian.Uint32(data[m:])
+	}
 	return nil
 }
 
@@ -492,7 +498,9 @@ func (v *Version) Bytes() []byte {
 	if v.KeepOnlyLatestState {
 		mask |= keepOnlyLatestStateBit
 	}
-	return append([]byte(v.Value), '\x00', byte(v.StoragePrefix), mask)
+	res := append([]byte(v.Value), '\x00', byte(v.StoragePrefix), mask, 0, 0, 0, 0)
+	binary.LittleEndian.PutUint32(res[len(res)-4:], v.Magic)
+	return res
 }
 
 func (dao *Simple) mkKeyPrefix(k storage.KeyPrefix) []byte {