plugeth/signer/core/api.go
Martin Holst Swende 5f94f8c7e7 signer: change the stdio jsonrpc to use legacy namespace conventions (#19047)
This PR will will break existing UIs, since it changes all calls like ApproveSignTransaction to be on the form ui_approveSignTransaction.

This is to make it possible for the UI to reuse the json-rpc library from go-ethereum, which uses this convention.

Also, this PR removes some unused structs, after import/export were removed from the external api (so no longer needs internal methods for approval)

One more breaking change is introduced, removing passwords from the ApproveSignTxResponse and the likes. This makes the manual interface more like the rulebased interface, and integrates nicely with the credential storage. Thus, the way it worked before, it would be tempting for the UI to implement 'remember password' functionality. The way it is now, it will be easy instead to tell clef to store passwords and use them.

If a pw is not found in the credential store, the user is prompted to provide the password.
2019-03-07 11:56:08 +02:00

525 lines
18 KiB
Go

// Copyright 2018 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// go-ethereum is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
package core
import (
"context"
"encoding/json"
"errors"
"fmt"
"math/big"
"reflect"
"strings"
"github.com/ethereum/go-ethereum/accounts"
"github.com/ethereum/go-ethereum/accounts/keystore"
"github.com/ethereum/go-ethereum/accounts/usbwallet"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/hexutil"
"github.com/ethereum/go-ethereum/internal/ethapi"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/rlp"
"github.com/ethereum/go-ethereum/signer/storage"
)
const (
// numberOfAccountsToDerive For hardware wallets, the number of accounts to derive
numberOfAccountsToDerive = 10
// ExternalAPIVersion -- see extapi_changelog.md
ExternalAPIVersion = "6.0.0"
// InternalAPIVersion -- see intapi_changelog.md
InternalAPIVersion = "6s.0.0"
)
// ExternalAPI defines the external API through which signing requests are made.
type ExternalAPI interface {
// List available accounts
List(ctx context.Context) ([]common.Address, error)
// New request to create a new account
New(ctx context.Context) (common.Address, error)
// SignTransaction request to sign the specified transaction
SignTransaction(ctx context.Context, args SendTxArgs, methodSelector *string) (*ethapi.SignTransactionResult, error)
// SignData - request to sign the given data (plus prefix)
SignData(ctx context.Context, contentType string, addr common.MixedcaseAddress, data interface{}) (hexutil.Bytes, error)
// SignTypedData - request to sign the given structured data (plus prefix)
SignTypedData(ctx context.Context, addr common.MixedcaseAddress, data TypedData) (hexutil.Bytes, error)
// EcRecover - recover public key from given message and signature
EcRecover(ctx context.Context, data hexutil.Bytes, sig hexutil.Bytes) (common.Address, error)
// Version info about the APIs
Version(ctx context.Context) (string, error)
}
// UIClientAPI specifies what method a UI needs to implement to be able to be used as a
// UI for the signer
type UIClientAPI interface {
// ApproveTx prompt the user for confirmation to request to sign Transaction
ApproveTx(request *SignTxRequest) (SignTxResponse, error)
// ApproveSignData prompt the user for confirmation to request to sign data
ApproveSignData(request *SignDataRequest) (SignDataResponse, error)
// ApproveListing prompt the user for confirmation to list accounts
// the list of accounts to list can be modified by the UI
ApproveListing(request *ListRequest) (ListResponse, error)
// ApproveNewAccount prompt the user for confirmation to create new Account, and reveal to caller
ApproveNewAccount(request *NewAccountRequest) (NewAccountResponse, error)
// ShowError displays error message to user
ShowError(message string)
// ShowInfo displays info message to user
ShowInfo(message string)
// OnApprovedTx notifies the UI about a transaction having been successfully signed.
// This method can be used by a UI to keep track of e.g. how much has been sent to a particular recipient.
OnApprovedTx(tx ethapi.SignTransactionResult)
// OnSignerStartup is invoked when the signer boots, and tells the UI info about external API location and version
// information
OnSignerStartup(info StartupInfo)
// OnInputRequired is invoked when clef requires user input, for example master password or
// pin-code for unlocking hardware wallets
OnInputRequired(info UserInputRequest) (UserInputResponse, error)
// RegisterUIServer tells the UI to use the given UIServerAPI for ui->clef communication
RegisterUIServer(api *UIServerAPI)
}
// SignerAPI defines the actual implementation of ExternalAPI
type SignerAPI struct {
chainID *big.Int
am *accounts.Manager
UI UIClientAPI
validator *Validator
rejectMode bool
credentials storage.Storage
}
// Metadata about a request
type Metadata struct {
Remote string `json:"remote"`
Local string `json:"local"`
Scheme string `json:"scheme"`
UserAgent string `json:"User-Agent"`
Origin string `json:"Origin"`
}
func StartClefAccountManager(ksLocation string, nousb, lightKDF bool) *accounts.Manager {
var (
backends []accounts.Backend
n, p = keystore.StandardScryptN, keystore.StandardScryptP
)
if lightKDF {
n, p = keystore.LightScryptN, keystore.LightScryptP
}
// support password based accounts
if len(ksLocation) > 0 {
backends = append(backends, keystore.NewKeyStore(ksLocation, n, p))
}
if !nousb {
// Start a USB hub for Ledger hardware wallets
if ledgerhub, err := usbwallet.NewLedgerHub(); err != nil {
log.Warn(fmt.Sprintf("Failed to start Ledger hub, disabling: %v", err))
} else {
backends = append(backends, ledgerhub)
log.Debug("Ledger support enabled")
}
// Start a USB hub for Trezor hardware wallets
if trezorhub, err := usbwallet.NewTrezorHub(); err != nil {
log.Warn(fmt.Sprintf("Failed to start Trezor hub, disabling: %v", err))
} else {
backends = append(backends, trezorhub)
log.Debug("Trezor support enabled")
}
}
return accounts.NewManager(backends...)
}
// MetadataFromContext extracts Metadata from a given context.Context
func MetadataFromContext(ctx context.Context) Metadata {
m := Metadata{"NA", "NA", "NA", "", ""} // batman
if v := ctx.Value("remote"); v != nil {
m.Remote = v.(string)
}
if v := ctx.Value("scheme"); v != nil {
m.Scheme = v.(string)
}
if v := ctx.Value("local"); v != nil {
m.Local = v.(string)
}
if v := ctx.Value("Origin"); v != nil {
m.Origin = v.(string)
}
if v := ctx.Value("User-Agent"); v != nil {
m.UserAgent = v.(string)
}
return m
}
// String implements Stringer interface
func (m Metadata) String() string {
s, err := json.Marshal(m)
if err == nil {
return string(s)
}
return err.Error()
}
// types for the requests/response types between signer and UI
type (
// SignTxRequest contains info about a Transaction to sign
SignTxRequest struct {
Transaction SendTxArgs `json:"transaction"`
Callinfo []ValidationInfo `json:"call_info"`
Meta Metadata `json:"meta"`
}
// SignTxResponse result from SignTxRequest
SignTxResponse struct {
//The UI may make changes to the TX
Transaction SendTxArgs `json:"transaction"`
Approved bool `json:"approved"`
}
SignDataRequest struct {
ContentType string `json:"content_type"`
Address common.MixedcaseAddress `json:"address"`
Rawdata []byte `json:"raw_data"`
Message []*NameValueType `json:"message"`
Hash hexutil.Bytes `json:"hash"`
Meta Metadata `json:"meta"`
}
SignDataResponse struct {
Approved bool `json:"approved"`
}
NewAccountRequest struct {
Meta Metadata `json:"meta"`
}
NewAccountResponse struct {
Approved bool `json:"approved"`
}
ListRequest struct {
Accounts []accounts.Account `json:"accounts"`
Meta Metadata `json:"meta"`
}
ListResponse struct {
Accounts []accounts.Account `json:"accounts"`
}
Message struct {
Text string `json:"text"`
}
StartupInfo struct {
Info map[string]interface{} `json:"info"`
}
UserInputRequest struct {
Title string `json:"title"`
Prompt string `json:"prompt"`
IsPassword bool `json:"isPassword"`
}
UserInputResponse struct {
Text string `json:"text"`
}
)
var ErrRequestDenied = errors.New("Request denied")
// NewSignerAPI creates a new API that can be used for Account management.
// ksLocation specifies the directory where to store the password protected private
// key that is generated when a new Account is created.
// noUSB disables USB support that is required to support hardware devices such as
// ledger and trezor.
func NewSignerAPI(am *accounts.Manager, chainID int64, noUSB bool, ui UIClientAPI, abidb *AbiDb, advancedMode bool, credentials storage.Storage) *SignerAPI {
if advancedMode {
log.Info("Clef is in advanced mode: will warn instead of reject")
}
signer := &SignerAPI{big.NewInt(chainID), am, ui, NewValidator(abidb), !advancedMode, credentials}
if !noUSB {
signer.startUSBListener()
}
return signer
}
func (api *SignerAPI) openTrezor(url accounts.URL) {
resp, err := api.UI.OnInputRequired(UserInputRequest{
Prompt: "Pin required to open Trezor wallet\n" +
"Look at the device for number positions\n\n" +
"7 | 8 | 9\n" +
"--+---+--\n" +
"4 | 5 | 6\n" +
"--+---+--\n" +
"1 | 2 | 3\n\n",
IsPassword: true,
Title: "Trezor unlock",
})
if err != nil {
log.Warn("failed getting trezor pin", "err", err)
return
}
// We're using the URL instead of the pointer to the
// Wallet -- perhaps it is not actually present anymore
w, err := api.am.Wallet(url.String())
if err != nil {
log.Warn("wallet unavailable", "url", url)
return
}
err = w.Open(resp.Text)
if err != nil {
log.Warn("failed to open wallet", "wallet", url, "err", err)
return
}
}
// startUSBListener starts a listener for USB events, for hardware wallet interaction
func (api *SignerAPI) startUSBListener() {
events := make(chan accounts.WalletEvent, 16)
am := api.am
am.Subscribe(events)
go func() {
// Open any wallets already attached
for _, wallet := range am.Wallets() {
if err := wallet.Open(""); err != nil {
log.Warn("Failed to open wallet", "url", wallet.URL(), "err", err)
if err == usbwallet.ErrTrezorPINNeeded {
go api.openTrezor(wallet.URL())
}
}
}
// Listen for wallet event till termination
for event := range events {
switch event.Kind {
case accounts.WalletArrived:
if err := event.Wallet.Open(""); err != nil {
log.Warn("New wallet appeared, failed to open", "url", event.Wallet.URL(), "err", err)
if err == usbwallet.ErrTrezorPINNeeded {
go api.openTrezor(event.Wallet.URL())
}
}
case accounts.WalletOpened:
status, _ := event.Wallet.Status()
log.Info("New wallet appeared", "url", event.Wallet.URL(), "status", status)
derivationPath := accounts.DefaultBaseDerivationPath
if event.Wallet.URL().Scheme == "ledger" {
derivationPath = accounts.DefaultLedgerBaseDerivationPath
}
var nextPath = derivationPath
// Derive first N accounts, hardcoded for now
for i := 0; i < numberOfAccountsToDerive; i++ {
acc, err := event.Wallet.Derive(nextPath, true)
if err != nil {
log.Warn("account derivation failed", "error", err)
} else {
log.Info("derived account", "address", acc.Address)
}
nextPath[len(nextPath)-1]++
}
case accounts.WalletDropped:
log.Info("Old wallet dropped", "url", event.Wallet.URL())
event.Wallet.Close()
}
}
}()
}
// List returns the set of wallet this signer manages. Each wallet can contain
// multiple accounts.
func (api *SignerAPI) List(ctx context.Context) ([]common.Address, error) {
var accs []accounts.Account
for _, wallet := range api.am.Wallets() {
accs = append(accs, wallet.Accounts()...)
}
result, err := api.UI.ApproveListing(&ListRequest{Accounts: accs, Meta: MetadataFromContext(ctx)})
if err != nil {
return nil, err
}
if result.Accounts == nil {
return nil, ErrRequestDenied
}
addresses := make([]common.Address, 0)
for _, acc := range result.Accounts {
addresses = append(addresses, acc.Address)
}
return addresses, nil
}
// New creates a new password protected Account. The private key is protected with
// the given password. Users are responsible to backup the private key that is stored
// in the keystore location thas was specified when this API was created.
func (api *SignerAPI) New(ctx context.Context) (common.Address, error) {
be := api.am.Backends(keystore.KeyStoreType)
if len(be) == 0 {
return common.Address{}, errors.New("password based accounts not supported")
}
if resp, err := api.UI.ApproveNewAccount(&NewAccountRequest{MetadataFromContext(ctx)}); err != nil {
return common.Address{}, err
} else if !resp.Approved {
return common.Address{}, ErrRequestDenied
}
// Three retries to get a valid password
for i := 0; i < 3; i++ {
resp, err := api.UI.OnInputRequired(UserInputRequest{
"New account password",
fmt.Sprintf("Please enter a password for the new account to be created (attempt %d of 3)", i),
true})
if err != nil {
log.Warn("error obtaining password", "attempt", i, "error", err)
continue
}
if pwErr := ValidatePasswordFormat(resp.Text); pwErr != nil {
api.UI.ShowError(fmt.Sprintf("Account creation attempt #%d failed due to password requirements: %v", (i + 1), pwErr))
} else {
// No error
acc, err := be[0].(*keystore.KeyStore).NewAccount(resp.Text)
return acc.Address, err
}
}
// Otherwise fail, with generic error message
return common.Address{}, errors.New("account creation failed")
}
// logDiff logs the difference between the incoming (original) transaction and the one returned from the signer.
// it also returns 'true' if the transaction was modified, to make it possible to configure the signer not to allow
// UI-modifications to requests
func logDiff(original *SignTxRequest, new *SignTxResponse) bool {
modified := false
if f0, f1 := original.Transaction.From, new.Transaction.From; !reflect.DeepEqual(f0, f1) {
log.Info("Sender-account changed by UI", "was", f0, "is", f1)
modified = true
}
if t0, t1 := original.Transaction.To, new.Transaction.To; !reflect.DeepEqual(t0, t1) {
log.Info("Recipient-account changed by UI", "was", t0, "is", t1)
modified = true
}
if g0, g1 := original.Transaction.Gas, new.Transaction.Gas; g0 != g1 {
modified = true
log.Info("Gas changed by UI", "was", g0, "is", g1)
}
if g0, g1 := big.Int(original.Transaction.GasPrice), big.Int(new.Transaction.GasPrice); g0.Cmp(&g1) != 0 {
modified = true
log.Info("GasPrice changed by UI", "was", g0, "is", g1)
}
if v0, v1 := big.Int(original.Transaction.Value), big.Int(new.Transaction.Value); v0.Cmp(&v1) != 0 {
modified = true
log.Info("Value changed by UI", "was", v0, "is", v1)
}
if d0, d1 := original.Transaction.Data, new.Transaction.Data; d0 != d1 {
d0s := ""
d1s := ""
if d0 != nil {
d0s = hexutil.Encode(*d0)
}
if d1 != nil {
d1s = hexutil.Encode(*d1)
}
if d1s != d0s {
modified = true
log.Info("Data changed by UI", "was", d0s, "is", d1s)
}
}
if n0, n1 := original.Transaction.Nonce, new.Transaction.Nonce; n0 != n1 {
modified = true
log.Info("Nonce changed by UI", "was", n0, "is", n1)
}
return modified
}
func (api *SignerAPI) lookupPassword(address common.Address) string {
return api.credentials.Get(strings.ToLower(address.String()))
}
func (api *SignerAPI) lookupOrQueryPassword(address common.Address, title, prompt string) (string, error) {
if pw := api.lookupPassword(address); pw != "" {
return pw, nil
} else {
pwResp, err := api.UI.OnInputRequired(UserInputRequest{title, prompt, true})
if err != nil {
log.Warn("error obtaining password", "error", err)
// We'll not forward the error here, in case the error contains info about the response from the UI,
// which could leak the password if it was malformed json or something
return "", errors.New("internal error")
}
return pwResp.Text, nil
}
}
// SignTransaction signs the given Transaction and returns it both as json and rlp-encoded form
func (api *SignerAPI) SignTransaction(ctx context.Context, args SendTxArgs, methodSelector *string) (*ethapi.SignTransactionResult, error) {
var (
err error
result SignTxResponse
)
msgs, err := api.validator.ValidateTransaction(&args, methodSelector)
if err != nil {
return nil, err
}
// If we are in 'rejectMode', then reject rather than show the user warnings
if api.rejectMode {
if err := msgs.getWarnings(); err != nil {
return nil, err
}
}
req := SignTxRequest{
Transaction: args,
Meta: MetadataFromContext(ctx),
Callinfo: msgs.Messages,
}
// Process approval
result, err = api.UI.ApproveTx(&req)
if err != nil {
return nil, err
}
if !result.Approved {
return nil, ErrRequestDenied
}
// Log changes made by the UI to the signing-request
logDiff(&req, &result)
var (
acc accounts.Account
wallet accounts.Wallet
)
acc = accounts.Account{Address: result.Transaction.From.Address()}
wallet, err = api.am.Find(acc)
if err != nil {
return nil, err
}
// Convert fields into a real transaction
var unsignedTx = result.Transaction.toTransaction()
// Get the password for the transaction
pw, err := api.lookupOrQueryPassword(acc.Address, "Account password",
fmt.Sprintf("Please enter the password for account %s", acc.Address.String()))
if err != nil {
return nil, err
}
// The one to sign is the one that was returned from the UI
signedTx, err := wallet.SignTxWithPassphrase(acc, pw, unsignedTx, api.chainID)
if err != nil {
api.UI.ShowError(err.Error())
return nil, err
}
rlpdata, err := rlp.EncodeToBytes(signedTx)
response := ethapi.SignTransactionResult{Raw: rlpdata, Tx: signedTx}
// Finally, send the signed tx to the UI
api.UI.OnApprovedTx(response)
// ...and to the external caller
return &response, nil
}
// Returns the external api version. This method does not require user acceptance. Available methods are
// available via enumeration anyway, and this info does not contain user-specific data
func (api *SignerAPI) Version(ctx context.Context) (string, error) {
return ExternalAPIVersion, nil
}