Re-implement removal of genesis persistence in state db (#1295)

* Self-contained solution

* Retrieve new UT from #1017

* Keep changelog from #1017

* Updated changelog

* Appease linter

* Appease linter 2

---------

Co-authored-by: Jasmina Malicevic <jasmina.dustinac@gmail.com>

.changelog/unreleased/improvements/1017-remove-genesis-persistence-in-state-db.md

@@ -0,0 +1,3 @@
+- `[node]` Remove genesis persistence in state db, replaced by a hash
+  ([cometbft/cometbft\#1017](https://github.com/cometbft/cometbft/pull/1017),
+  [cometbft/cometbft\#1295](https://github.com/cometbft/cometbft/pull/1295))

node/node_test.go

@@ -18,9 +18,12 @@ import (
 	"github.com/cometbft/cometbft/abci/example/kvstore"
 	cfg "github.com/cometbft/cometbft/config"
 	"github.com/cometbft/cometbft/crypto/ed25519"
+	"github.com/cometbft/cometbft/crypto/tmhash"
 	"github.com/cometbft/cometbft/evidence"
 	"github.com/cometbft/cometbft/internal/test"
+	cmtjson "github.com/cometbft/cometbft/libs/json"
 	"github.com/cometbft/cometbft/libs/log"
+	cmtos "github.com/cometbft/cometbft/libs/os"
 	cmtrand "github.com/cometbft/cometbft/libs/rand"
 	mempl "github.com/cometbft/cometbft/mempool"
 	"github.com/cometbft/cometbft/p2p"
@@ -465,6 +468,73 @@ func TestNodeNewNodeCustomReactors(t *testing.T) {
 	assert.Contains(t, channels, cr.Channels[0].ID)
 }
 
+func TestNodeNewNodeGenesisHashMismatch(t *testing.T) {
+	config := test.ResetTestRoot("node_new_node_genesis_hash")
+	defer os.RemoveAll(config.RootDir)
+
+	// Use goleveldb so we can reuse the same db for the second NewNode()
+	config.DBBackend = string(dbm.GoLevelDBBackend)
+
+	nodeKey, err := p2p.LoadOrGenNodeKey(config.NodeKeyFile())
+	require.NoError(t, err)
+
+	n, err := NewNode(
+		context.Background(),
+		config,
+		privval.LoadOrGenFilePV(config.PrivValidatorKeyFile(), config.PrivValidatorStateFile()),
+		nodeKey,
+		proxy.DefaultClientCreator(config.ProxyApp, config.ABCI, config.DBDir()),
+		DefaultGenesisDocProviderFunc(config),
+		cfg.DefaultDBProvider,
+		DefaultMetricsProvider(config.Instrumentation),
+		log.TestingLogger(),
+	)
+	require.NoError(t, err)
+
+	// Start and stop to close the db for later reading
+	err = n.Start()
+	require.NoError(t, err)
+
+	err = n.Stop()
+	require.NoError(t, err)
+
+	// Ensure the genesis doc hash is saved to db
+	stateDB, err := cfg.DefaultDBProvider(&cfg.DBContext{ID: "state", Config: config})
+	require.NoError(t, err)
+
+	genDocHash, err := stateDB.Get(genesisDocHashKey)
+	require.NoError(t, err)
+	require.NotNil(t, genDocHash, "genesis doc hash should be saved in db")
+	require.Len(t, genDocHash, tmhash.Size)
+
+	err = stateDB.Close()
+	require.NoError(t, err)
+
+	// Modify the genesis file chain ID to get a different hash
+	genBytes := cmtos.MustReadFile(config.GenesisFile())
+	var genesisDoc types.GenesisDoc
+	err = cmtjson.Unmarshal(genBytes, &genesisDoc)
+	require.NoError(t, err)
+
+	genesisDoc.ChainID = "different-chain-id"
+	err = genesisDoc.SaveAs(config.GenesisFile())
+	require.NoError(t, err)
+
+	_, err = NewNode(
+		context.Background(),
+		config,
+		privval.LoadOrGenFilePV(config.PrivValidatorKeyFile(), config.PrivValidatorStateFile()),
+		nodeKey,
+		proxy.DefaultClientCreator(config.ProxyApp, config.ABCI, config.DBDir()),
+		DefaultGenesisDocProviderFunc(config),
+		cfg.DefaultDBProvider,
+		DefaultMetricsProvider(config.Instrumentation),
+		log.TestingLogger(),
+	)
+	require.Error(t, err, "NewNode should error when genesisDoc is changed")
+	require.Equal(t, "genesis doc hash in db does not match loaded genesis doc", err.Error())
+}
+
 func state(nVals int, height int64) (sm.State, dbm.DB, []types.PrivValidator) {
 	privVals := make([]types.PrivValidator, nVals)
 	vals := make([]types.GenesisValidator, nVals)

node/setup.go

@@ -3,7 +3,6 @@ package node
 import (
 	"bytes"
 	"context"
-	"errors"
 	"fmt"
 	"net"
 	"strings"
@@ -18,6 +17,7 @@ import (
 	cfg "github.com/cometbft/cometbft/config"
 	cs "github.com/cometbft/cometbft/consensus"
 	"github.com/cometbft/cometbft/crypto"
+	"github.com/cometbft/cometbft/crypto/tmhash"
 	"github.com/cometbft/cometbft/evidence"
 	"github.com/cometbft/cometbft/statesync"
 
@@ -529,7 +529,8 @@ func startStateSync(
 
 //------------------------------------------------------------------------------
 
-var genesisDocKey = []byte("genesisDoc")
+// var genesisDocKey = []byte("genesisDoc")
+var genesisDocHashKey = []byte("genesisDocHash")
 
 // LoadStateFromDBOrGenesisDocProvider attempts to load the state from the
 // database, or creates one using the given genesisDocProvider. On success this also
@@ -538,22 +539,34 @@ func LoadStateFromDBOrGenesisDocProvider(
 	stateDB dbm.DB,
 	genesisDocProvider GenesisDocProvider,
 ) (sm.State, *types.GenesisDoc, error) {
-	// Get genesis doc
-	genDoc, err := loadGenesisDoc(stateDB)
+	// Get genesis doc hash
+	genDocHash, err := stateDB.Get(genesisDocHashKey)
 	if err != nil {
-		genDoc, err = genesisDocProvider()
-		if err != nil {
-			return sm.State{}, nil, err
-		}
+		return sm.State{}, nil, fmt.Errorf("error retrieving genesis doc hash: %w", err)
+	}
+	genDoc, err := genesisDocProvider()
+	if err != nil {
+		return sm.State{}, nil, err
+	}
 
-		err = genDoc.ValidateAndComplete()
-		if err != nil {
-			return sm.State{}, nil, fmt.Errorf("error in genesis doc: %w", err)
+	if err := genDoc.ValidateAndComplete(); err != nil {
+		return sm.State{}, nil, fmt.Errorf("error in genesis doc: %w", err)
+	}
+
+	genDocBytes, err := cmtjson.Marshal(genDoc)
+	if err != nil {
+		return sm.State{}, nil, fmt.Errorf("failed to save genesis doc hash due to marshaling error: %w", err)
+	}
+
+	incomingGenDocHash := tmhash.Sum(genDocBytes)
+	if len(genDocHash) == 0 {
+		// Save the genDoc hash in the store if it doesn't already exist for future verification
+		if err := stateDB.SetSync(genesisDocHashKey, incomingGenDocHash); err != nil {
+			return sm.State{}, nil, fmt.Errorf("failed to save genesis doc hash to db: %w", err)
 		}
-		// save genesis doc to prevent a certain class of user errors (e.g. when it
-		// was changed, accidentally or not). Also good for audit trail.
-		if err := saveGenesisDoc(stateDB, genDoc); err != nil {
-			return sm.State{}, nil, err
+	} else {
+		if !bytes.Equal(genDocHash, incomingGenDocHash) {
+			return sm.State{}, nil, fmt.Errorf("genesis doc hash in db does not match loaded genesis doc")
 		}
 	}
 	stateStore := sm.NewStore(stateDB, sm.StoreOptions{
@@ -566,32 +579,6 @@ func LoadStateFromDBOrGenesisDocProvider(
 	return state, genDoc, nil
 }
 
-// panics if failed to unmarshal bytes
-func loadGenesisDoc(db dbm.DB) (*types.GenesisDoc, error) {
-	b, err := db.Get(genesisDocKey)
-	if err != nil {
-		panic(err)
-	}
-	if len(b) == 0 {
-		return nil, errors.New("genesis doc not found")
-	}
-	var genDoc *types.GenesisDoc
-	err = cmtjson.Unmarshal(b, &genDoc)
-	if err != nil {
-		panic(fmt.Sprintf("Failed to load genesis doc due to unmarshaling error: %v (bytes: %X)", err, b))
-	}
-	return genDoc, nil
-}
-
-// panics if failed to marshal the given genesis document
-func saveGenesisDoc(db dbm.DB, genDoc *types.GenesisDoc) error {
-	b, err := cmtjson.Marshal(genDoc)
-	if err != nil {
-		return fmt.Errorf("failed to save genesis doc due to marshaling error: %w", err)
-	}
-	return db.SetSync(genesisDocKey, b)
-}
-
 func createAndStartPrivValidatorSocketClient(
 	listenAddr,
 	chainID string,