internal/ethapi: reject non-replay-protected txs over RPC (#22339)

This PR prevents users from submitting transactions without EIP-155 enabled. This behaviour can be overridden by specifying the flag --rpc.allow-unprotected-txs=true.

cmd/geth/main.go

@@ -199,6 +199,7 @@ var (
 		utils.InsecureUnlockAllowedFlag,
 		utils.RPCGlobalGasCapFlag,
 		utils.RPCGlobalTxFeeCapFlag,
+		utils.AllowUnprotectedTxs,
 	}
 
 	whisperFlags = []cli.Flag{

cmd/utils/flags.go

@@ -593,6 +593,10 @@ var (
 		Name:  "preload",
 		Usage: "Comma separated list of JavaScript files to preload into the console",
 	}
+	AllowUnprotectedTxs = cli.BoolFlag{
+		Name:  "rpc.allow-unprotected-txs",
+		Usage: "Allow for unprotected (non EIP155 signed) transactions to be submitted via RPC",
+	}
 
 	// Network Settings
 	MaxPeersFlag = cli.IntFlag{
@@ -966,6 +970,9 @@ func setHTTP(ctx *cli.Context, cfg *node.Config) {
 	if ctx.GlobalIsSet(HTTPPathPrefixFlag.Name) {
 		cfg.HTTPPathPrefix = ctx.GlobalString(HTTPPathPrefixFlag.Name)
 	}
+	if ctx.GlobalIsSet(AllowUnprotectedTxs.Name) {
+		cfg.AllowUnprotectedTxs = ctx.GlobalBool(AllowUnprotectedTxs.Name)
+	}
 }
 
 // setGraphQL creates the GraphQL listener interface string from the set

eth/api_backend.go

@@ -42,6 +42,7 @@ import (
 // EthAPIBackend implements ethapi.Backend for full nodes
 type EthAPIBackend struct {
 	extRPCEnabled       bool
+	allowUnprotectedTxs bool
 	eth                 *Ethereum
 	gpo                 *gasprice.Oracle
 }
@@ -292,6 +293,10 @@ func (b *EthAPIBackend) ExtRPCEnabled() bool {
 	return b.extRPCEnabled
 }
 
+func (b *EthAPIBackend) UnprotectedAllowed() bool {
+	return b.allowUnprotectedTxs
+}
+
 func (b *EthAPIBackend) RPCGasCap() uint64 {
 	return b.eth.config.RPCGasCap
 }

eth/backend.go

@@ -222,7 +222,10 @@ func New(stack *node.Node, config *ethconfig.Config) (*Ethereum, error) {
 	eth.miner = miner.New(eth, &config.Miner, chainConfig, eth.EventMux(), eth.engine, eth.isLocalBlock)
 	eth.miner.SetExtra(makeExtraData(config.Miner.ExtraData))
 
-	eth.APIBackend = &EthAPIBackend{stack.Config().ExtRPCEnabled(), eth, nil}
+	eth.APIBackend = &EthAPIBackend{stack.Config().ExtRPCEnabled(), stack.Config().AllowUnprotectedTxs, eth, nil}
+	if eth.APIBackend.allowUnprotectedTxs {
+		log.Info("Unprotected transactions allowed")
+	}
 	gpoParams := config.GPO
 	if gpoParams.Default == nil {
 		gpoParams.Default = config.Miner.GasPrice

internal/ethapi/api.go

@@ -1555,6 +1555,10 @@ func SubmitTransaction(ctx context.Context, b Backend, tx *types.Transaction) (c
 	if err := checkTxFee(tx.GasPrice(), tx.Gas(), b.RPCTxFeeCap()); err != nil {
 		return common.Hash{}, err
 	}
+	if !b.UnprotectedAllowed() && !tx.Protected() {
+		// Ensure only eip155 signed transactions are submitted if EIP155Required is set.
+		return common.Hash{}, errors.New("only replay-protected (EIP-155) transactions allowed over RPC")
+	}
 	if err := b.SendTx(ctx, tx); err != nil {
 		return common.Hash{}, err
 	}

internal/ethapi/backend.go

@@ -47,6 +47,7 @@ type Backend interface {
 	ExtRPCEnabled() bool
 	RPCGasCap() uint64        // global gas cap for eth_call over rpc: DoS protection
 	RPCTxFeeCap() float64     // global tx fee cap for all transaction related APIs
+	UnprotectedAllowed() bool // allows only for EIP155 transactions.
 
 	// Blockchain API
 	SetHead(number uint64)

les/api_backend.go

@@ -41,6 +41,7 @@ import (
 
 type LesApiBackend struct {
 	extRPCEnabled       bool
+	allowUnprotectedTxs bool
 	eth                 *LightEthereum
 	gpo                 *gasprice.Oracle
 }
@@ -263,6 +264,10 @@ func (b *LesApiBackend) ExtRPCEnabled() bool {
 	return b.extRPCEnabled
 }
 
+func (b *LesApiBackend) UnprotectedAllowed() bool {
+	return b.allowUnprotectedTxs
+}
+
 func (b *LesApiBackend) RPCGasCap() uint64 {
 	return b.eth.config.RPCGasCap
 }

les/client.go

@@ -157,7 +157,7 @@ func New(stack *node.Node, config *ethconfig.Config) (*LightEthereum, error) {
 		rawdb.WriteChainConfig(chainDb, genesisHash, chainConfig)
 	}
 
-	leth.ApiBackend = &LesApiBackend{stack.Config().ExtRPCEnabled(), leth, nil}
+	leth.ApiBackend = &LesApiBackend{stack.Config().ExtRPCEnabled(), stack.Config().AllowUnprotectedTxs, leth, nil}
 	gpoParams := config.GPO
 	if gpoParams.Default == nil {
 		gpoParams.Default = config.Miner.GasPrice

node/config.go

@@ -191,6 +191,9 @@ type Config struct {
 	staticNodesWarning     bool
 	trustedNodesWarning    bool
 	oldGethResourceWarning bool
+
+	// AllowUnprotectedTxs allows non EIP-155 protected transactions to be send over RPC.
+	AllowUnprotectedTxs bool `toml:",omitempty"`
 }
 
 // IPCEndpoint resolves an IPC endpoint based on a configured value, taking into