Add Wallet APIs for local development

Makefile

@@ -44,4 +44,4 @@ start:
 .PHONY: start-local
 start-local:
 	rm -rf db/
-	go run cmd/main/main.go --flow-network-id=flow-emulator --coinbase=FACF71692421039876a5BB4F10EF7A439D8ef61E --coa-address=f8d6e0586b0a20c7 --coa-key=2619878f0e2ff438d17835c2a4561cb87b4d24d72d12ec34569acd0dd4af7c21 --coa-resource-create=true --gas-price=0 --log-writer=console
+	go run cmd/main/main.go --flow-network-id=flow-emulator --coinbase=FACF71692421039876a5BB4F10EF7A439D8ef61E --coa-address=f8d6e0586b0a20c7 --coa-key=2619878f0e2ff438d17835c2a4561cb87b4d24d72d12ec34569acd0dd4af7c21 --wallet-api-key=2619878f0e2ff438d17835c2a4561cb87b4d24d72d12ec34569acd0dd4af7c21 --coa-resource-create=true --gas-price=0 --log-writer=console

api/api.go

@@ -33,6 +33,7 @@ func SupportedAPIs(
 	streamAPI *StreamAPI,
 	pullAPI *PullAPI,
 	debugAPI *DebugAPI,
+	walletAPI *WalletAPI,
 	config *config.Config,
 ) []rpc.API {
 	apis := []rpc.API{{
@@ -63,6 +64,13 @@ func SupportedAPIs(
 		})
 	}
 
+	if walletAPI != nil {
+		apis = append(apis, rpc.API{
+			Namespace: "eth",
+			Service:   walletAPI,
+		})
+	}
+
 	return apis
 }
 
@@ -962,46 +970,6 @@ This is because a decision to not support this API was made either because we do
 ever or we don't support it at this phase.
 */
 
-// Accounts returns the collection of accounts this node manages.
-func (b *BlockChainAPI) Accounts() []common.Address {
-	return []common.Address{}
-}
-
-// Sign calculates an ECDSA signature for:
-// keccak256("\x19Ethereum Signed Message:\n" + len(message) + message).
-//
-// Note, the produced signature conforms to the secp256k1 curve R, S and V values,
-// where the V value will be 27 or 28 for legacy reasons.
-//
-// The account associated with addr must be unlocked.
-//
-// https://github.com/ethereum/wiki/wiki/JSON-RPC#eth_sign
-func (b *BlockChainAPI) Sign(
-	addr common.Address,
-	data hexutil.Bytes,
-) (hexutil.Bytes, error) {
-	return nil, errs.ErrNotSupported
-}
-
-// SignTransaction will sign the given transaction with the from account.
-// The node needs to have the private key of the account corresponding with
-// the given from address and it needs to be unlocked.
-func (b *BlockChainAPI) SignTransaction(
-	ctx context.Context,
-	args TransactionArgs,
-) (*SignTransactionResult, error) {
-	return nil, errs.ErrNotSupported
-}
-
-// SendTransaction creates a transaction for the given argument, sign it
-// and submit it to the transaction pool.
-func (b *BlockChainAPI) SendTransaction(
-	ctx context.Context,
-	args TransactionArgs,
-) (common.Hash, error) {
-	return common.Hash{}, errs.ErrNotSupported
-}
-
 // GetProof returns the Merkle-proof for a given account and optionally some storage keys.
 func (b *BlockChainAPI) GetProof(
 	ctx context.Context,

api/wallet.go

@@ -0,0 +1,138 @@
+package api
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	evmEmulator "github.com/onflow/flow-go/fvm/evm/emulator"
+	"github.com/onflow/go-ethereum/accounts"
+	"github.com/onflow/go-ethereum/common"
+	"github.com/onflow/go-ethereum/common/hexutil"
+	"github.com/onflow/go-ethereum/core/types"
+	"github.com/onflow/go-ethereum/crypto"
+	"github.com/onflow/go-ethereum/rpc"
+
+	"github.com/onflow/flow-evm-gateway/config"
+)
+
+type WalletAPI struct {
+	net    *BlockChainAPI
+	config *config.Config
+}
+
+func NewWalletAPI(config *config.Config, net *BlockChainAPI) *WalletAPI {
+	return &WalletAPI{
+		net:    net,
+		config: config,
+	}
+}
+
+// Accounts returns the collection of accounts this node manages.
+func (w *WalletAPI) Accounts() ([]common.Address, error) {
+	return []common.Address{
+		crypto.PubkeyToAddress(w.config.WalletKey.PublicKey),
+	}, nil
+}
+
+// Sign calculates an ECDSA signature for:
+// keccak256("\x19Ethereum Signed Message:\n" + len(message) + message).
+//
+// Note, the produced signature conforms to the secp256k1 curve R, S and V values,
+// where the V value will be 27 or 28 for legacy reasons.
+//
+// The account associated with addr must be unlocked.
+//
+// https://github.com/ethereum/wiki/wiki/JSON-RPC#eth_sign
+func (w *WalletAPI) Sign(
+	addr common.Address,
+	data hexutil.Bytes,
+) (hexutil.Bytes, error) {
+	// Transform the given message to the following format:
+	// keccak256("\x19Ethereum Signed Message:\n"${message length}${message})
+	hash := accounts.TextHash(data)
+	// Sign the hash using plain ECDSA operations
+	signature, err := crypto.Sign(hash, w.config.WalletKey)
+	if err == nil {
+		// Transform V from 0/1 to 27/28 according to the yellow paper
+		signature[64] += 27
+	}
+
+	return signature, err
+}
+
+// SignTransaction will sign the given transaction with the from account.
+// The node needs to have the private key of the account corresponding with
+// the given from address and it needs to be unlocked.
+func (w *WalletAPI) SignTransaction(
+	ctx context.Context,
+	args TransactionArgs,
+) (*SignTransactionResult, error) {
+	if args.Gas == nil {
+		return nil, errors.New("gas not specified")
+	}
+	if args.GasPrice == nil && (args.MaxPriorityFeePerGas == nil || args.MaxFeePerGas == nil) {
+		return nil, errors.New("missing gasPrice or maxFeePerGas/maxPriorityFeePerGas")
+	}
+
+	accounts, err := w.Accounts()
+	if err != nil {
+		return nil, err
+	}
+	from := accounts[0]
+
+	nonce := uint64(0)
+	if args.Nonce != nil {
+		nonce = uint64(*args.Nonce)
+	} else {
+		num := rpc.BlockNumberOrHashWithNumber(rpc.LatestBlockNumber)
+		n, err := w.net.GetTransactionCount(ctx, from, &num)
+		if err != nil {
+			return nil, err
+		}
+		nonce = uint64(*n)
+	}
+
+	var data []byte
+	if args.Data != nil {
+		data = *args.Data
+	}
+
+	tx := types.NewTx(&types.LegacyTx{
+		Nonce:    nonce,
+		To:       args.To,
+		Value:    args.Value.ToInt(),
+		Gas:      uint64(*args.Gas),
+		GasPrice: args.GasPrice.ToInt(),
+		Data:     data,
+	})
+
+	signed, err := types.SignTx(tx, evmEmulator.GetDefaultSigner(), w.config.WalletKey)
+	if err != nil {
+		return nil, fmt.Errorf("error signing EVM transaction: %w", err)
+	}
+
+	raw, err := signed.MarshalBinary()
+	if err != nil {
+		return nil, err
+	}
+
+	return &SignTransactionResult{
+		Raw: raw,
+		Tx:  tx,
+	}, nil
+}
+
+// SendTransaction creates a transaction for the given argument, sign it
+// and submit it to the transaction pool.
+func (w *WalletAPI) SendTransaction(
+	ctx context.Context,
+	args TransactionArgs,
+) (common.Hash, error) {
+	signed, err := w.SignTransaction(ctx, args)
+	if err != nil {
+		return common.Hash{}, err
+	}
+
+	return w.net.SendRawTransaction(ctx, signed.Raw)
+}

bootstrap/bootstrap.go

@@ -344,11 +344,17 @@ func startServer(
 		debugAPI = api.NewDebugAPI(trace, blocks, logger)
 	}
 
+	var walletAPI *api.WalletAPI
+	if cfg.WalletEnabled {
+		walletAPI = api.NewWalletAPI(cfg, blockchainAPI)
+	}
+
 	supportedAPIs := api.SupportedAPIs(
 		blockchainAPI,
 		streamAPI,
 		pullAPI,
 		debugAPI,
+		walletAPI,
 		cfg,
 	)
 

config/config.go

@@ -1,6 +1,7 @@
 package config
 
 import (
+	"crypto/ecdsa"
 	"flag"
 	"fmt"
 	"io"
@@ -16,6 +17,7 @@ import (
 	"github.com/onflow/flow-go/fvm/evm/types"
 	flowGo "github.com/onflow/flow-go/model/flow"
 	"github.com/onflow/go-ethereum/common"
+	gethCrypto "github.com/onflow/go-ethereum/crypto"
 	"github.com/rs/zerolog"
 )
 
@@ -85,13 +87,37 @@ type Config struct {
 	TracesBucketName string
 	// TracesEnabled sets whether the node is supporting transaction traces.
 	TracesEnabled bool
+	// WalletEnabled sets whether wallet APIs are enabled
+	WalletEnabled bool
+	// WalletKey used for signing transactions
+	WalletKey *ecdsa.PrivateKey
 }
 
 func FromFlags() (*Config, error) {
 	cfg := &Config{}
-	var evmNetwork, coinbase, gas, coa, key, keysPath, flowNetwork, logLevel, logWriter, filterExpiry, accessSporkHosts, cloudKMSKeys, cloudKMSProjectID, cloudKMSLocationID, cloudKMSKeyRingID string
-	var streamTimeout int
-	var initHeight, forceStartHeight uint64
+	var (
+		evmNetwork,
+		coinbase,
+		gas,
+		coa,
+		key,
+		keysPath,
+		flowNetwork,
+		logLevel,
+		logWriter,
+		filterExpiry,
+		accessSporkHosts,
+		cloudKMSKeys,
+		cloudKMSProjectID,
+		cloudKMSLocationID,
+		cloudKMSKeyRingID,
+		walletKey string
+
+		streamTimeout int
+
+		initHeight,
+		forceStartHeight uint64
+	)
 
 	// parse from flags
 	flag.StringVar(&cfg.DatabaseDir, "database-dir", "./db", "Path to the directory for the database")
@@ -116,13 +142,14 @@ func FromFlags() (*Config, error) {
 	flag.StringVar(&cfg.AddressHeader, "address-header", "", "Address header that contains the client IP, this is useful when the server is behind a proxy that sets the source IP of the client. Leave empty if no proxy is used.")
 	flag.Uint64Var(&cfg.HeartbeatInterval, "heartbeat-interval", 100, "Heartbeat interval for AN event subscription")
 	flag.IntVar(&streamTimeout, "stream-timeout", 3, "Defines the timeout in seconds the server waits for the event to be sent to the client")
-	flag.Uint64Var(&forceStartHeight, "force-start-height", 0, "Force set starting Cadence height. This should only be used locally or for testing, never in production.")
+	flag.Uint64Var(&forceStartHeight, "force-start-height", 0, "Force set starting Cadence height. WARNING: This should only be used locally or for testing, never in production.")
 	flag.StringVar(&filterExpiry, "filter-expiry", "5m", "Filter defines the time it takes for an idle filter to expire")
 	flag.StringVar(&cfg.TracesBucketName, "traces-gcp-bucket", "", "GCP bucket name where transaction traces are stored")
 	flag.StringVar(&cloudKMSProjectID, "coa-cloud-kms-project-id", "", "The project ID containing the KMS keys, e.g. 'flow-evm-gateway'")
 	flag.StringVar(&cloudKMSLocationID, "coa-cloud-kms-location-id", "", "The location ID where the key ring is grouped into, e.g. 'global'")
 	flag.StringVar(&cloudKMSKeyRingID, "coa-cloud-kms-key-ring-id", "", "The key ring ID where the KMS keys exist, e.g. 'tx-signing'")
 	flag.StringVar(&cloudKMSKeys, "coa-cloud-kms-keys", "", `Names of the KMS keys and their versions as a comma separated list, e.g. "gw-key-6@1,gw-key-7@1,gw-key-8@1"`)
+	flag.StringVar(&walletKey, "wallet-api-key", "", "ECDSA private key used for wallet APIs. WARNING: This should only be used locally or for testing, never in production.")
 	flag.Parse()
 
 	if coinbase == "" {
@@ -262,6 +289,16 @@ func FromFlags() (*Config, error) {
 
 	cfg.TracesEnabled = cfg.TracesBucketName != ""
 
+	if walletKey != "" {
+		var k, err = gethCrypto.HexToECDSA(walletKey)
+		if err != nil {
+			return nil, fmt.Errorf("wrong private key for wallet API: %w", err)
+		}
+
+		cfg.WalletKey = k
+		cfg.WalletEnabled = true
+	}
+
 	// todo validate Config values
 	return cfg, nil
 }