feat: validate chain id

CHANGELOG.md

@@ -6,6 +6,16 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+
+### Added
+
+- Added verification to ensure CARTESI_BLOCKCHAIN_ID matches the id returned from the Ethereum node
+
+## Changed
+
+- Changed CARTESI_BLOCKCHAIN_ID type from int to uint
+
 ## [1.3.0] 2024-02-09
 
 ### Added

cmd/cartesi-rollups-node/chainid.go

@@ -0,0 +1,46 @@
+// (c) Cartesi and individual authors (see AUTHORS)
+// SPDX-License-Identifier: Apache-2.0 (see LICENSE)
+
+package main
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/cartesi/rollups-node/internal/config"
+	"github.com/ethereum/go-ethereum/ethclient"
+)
+
+const defaultTimeout = 3 * time.Second
+
+// Checks if the chain id from the configuration matches the chain id reported
+// by the Ethereum node. If they don't, it returns an error.
+func validateChainId(ctx context.Context, chainId uint64, ethereumNodeAddr string) error {
+	remoteChainId, err := getChainId(ctx, ethereumNodeAddr)
+	if err != nil {
+		config.ErrorLogger.Printf("Couldn't validate chainId: %v\n", err)
+	} else if chainId != remoteChainId {
+		return fmt.Errorf(
+			"chainId mismatch. Expected %v but Ethereum node returned %v",
+			chainId,
+			remoteChainId,
+		)
+	}
+	return nil
+}
+
+func getChainId(ctx context.Context, ethereumNodeAddr string) (uint64, error) {
+	ctx, cancel := context.WithTimeout(ctx, defaultTimeout)
+	defer cancel()
+
+	client, err := ethclient.Dial(ethereumNodeAddr)
+	if err != nil {
+		return 0, fmt.Errorf("Failed to create RPC client: %v", err)
+	}
+	chainId, err := client.ChainID(ctx)
+	if err != nil {
+		return 0, fmt.Errorf("Failed to get chain id: %v", err)
+	}
+	return chainId.Uint64(), nil
+}

cmd/cartesi-rollups-node/chainid_test.go

@@ -0,0 +1,48 @@
+// (c) Cartesi and individual authors (see AUTHORS)
+// SPDX-License-Identifier: Apache-2.0 (see LICENSE)
+
+package main
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/suite"
+)
+
+type ValidateChainIdSuite struct {
+	suite.Suite
+}
+
+func TestValidateChainId(t *testing.T) {
+	suite.Run(t, new(ValidateChainIdSuite))
+}
+
+func (s *ValidateChainIdSuite) TestItFailsIfChainIdsDoNotMatch() {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprintln(w, `{"jsonrpc":"2.0","id":67,"result":"0x7a69"}`)
+	}))
+	defer ts.Close()
+	localChainId := uint64(11111)
+
+	err := validateChainId(context.Background(), localChainId, ts.URL)
+
+	s.NotNil(err)
+}
+
+func (s *ValidateChainIdSuite) TestItReturnsNilIfChainIdsMatch() {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprintln(w, `{"jsonrpc":"2.0","id":67,"result":"0x7a69"}`)
+	}))
+	defer ts.Close()
+	localChainId := uint64(31337)
+
+	err := validateChainId(context.Background(), localChainId, ts.URL)
+
+	s.Nil(err)
+}

cmd/cartesi-rollups-node/main.go

@@ -20,6 +20,14 @@ func main() {
 	ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
 	defer stop()
 
+	if err := validateChainId(
+		ctx,
+		config.GetCartesiBlockchainId(),
+		config.GetCartesiBlockchainHttpEndpoint(),
+	); err != nil {
+		config.ErrorLogger.Fatal(err)
+	}
+
 	sunodoValidatorEnabled := config.GetCartesiExperimentalSunodoValidatorEnabled()
 	if !sunodoValidatorEnabled {
 		// add Redis first