feat: validate cartesi machine hash

cmd/cartesi-rollups-node/machinehash.go

@@ -0,0 +1,74 @@
+// (c) Cartesi and individual authors (see AUTHORS)
+// SPDX-License-Identifier: Apache-2.0 (see LICENSE)
+
+package main
+
+import (
+	"fmt"
+	"os"
+	"path"
+
+	"github.com/cartesi/rollups-node/pkg/contracts"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/ethclient"
+)
+
+const HASH_SIZE = 32
+
+// Validates if the hash from the Cartesi Machine at machineDir matches the template hash onchain.
+// It returns an error if it doesn't.
+func validateMachineHash(
+	machineDir string,
+	applicationAddress string,
+	ethereumNodeAddr string,
+) error {
+	offchainHash, err := getHash(machineDir)
+	if err != nil {
+		return err
+	}
+	onchainHash, err := getTemplateHash(applicationAddress, ethereumNodeAddr)
+	if err != nil {
+		return err
+	}
+	if offchainHash != onchainHash {
+		return fmt.Errorf(
+			"cartesi machine hash mismatch: expected %v but got %v",
+			onchainHash,
+			offchainHash,
+		)
+	}
+	return nil
+}
+
+// Reads the Cartesi Machine hash from machineDir. Returns the hash as
+// a hex string or an error
+func getHash(machineDir string) (string, error) {
+	path := path.Join(machineDir, "hash")
+	hash, err := os.ReadFile(path)
+	if err != nil {
+		return "", err
+	} else if len(hash) != HASH_SIZE {
+		return "", fmt.Errorf("Malformed hash: expected %v bytes, read %v", HASH_SIZE, len(hash))
+	}
+	return common.Bytes2Hex(hash), nil
+}
+
+// TODO: documentation
+func getTemplateHash(applicationAddress string, ethereumNodeAddr string) (string, error) {
+	client, err := ethclient.Dial(ethereumNodeAddr)
+	if err != nil {
+		return "", err
+	}
+	cartesiApplication, err := contracts.NewCartesiDAppCaller(
+		common.HexToAddress(applicationAddress),
+		client,
+	)
+	if err != nil {
+		return "", err
+	}
+	hash, err := cartesiApplication.GetTemplateHash(nil)
+	if err != nil {
+		return "", err
+	}
+	return common.Bytes2Hex(hash[:]), nil
+}

cmd/cartesi-rollups-node/main.go

@@ -20,6 +20,16 @@ func main() {
 	ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
 	defer stop()
 
+	if !config.GetCartesiFeatureDisableMachineHashCheck() {
+		if err := validateMachineHash(
+			config.GetCartesiSnapshotDir(),
+			config.GetCartesiContractsApplicationAddress(),
+			config.GetCartesiBlockchainHttpEndpoint(),
+		); err != nil {
+			config.ErrorLogger.Fatal(err)
+		}
+	}
+
 	sunodoValidatorEnabled := config.GetCartesiExperimentalSunodoValidatorEnabled()
 	if !sunodoValidatorEnabled {
 		// add Redis first