go-pulse/signer/core/api.go
Felix Lange 5bcbb2980b
rpc: add PeerInfo (#24255)
This replaces the sketchy and undocumented string context keys for HTTP requests
with a defined interface. Using string keys with context is discouraged because
they may clash with keys created by other packages.

We added these keys to make connection metadata available in the signer, so this
change also updates signer/core to use the new PeerInfo API.
2022-01-20 12:45:07 +01:00

650 lines
23 KiB
Go

// Copyright 2018 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library 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 Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package core
import (
"context"
"encoding/json"
"errors"
"fmt"
"math/big"
"os"
"reflect"
"github.com/ethereum/go-ethereum/accounts"
"github.com/ethereum/go-ethereum/accounts/keystore"
"github.com/ethereum/go-ethereum/accounts/scwallet"
"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/rpc"
"github.com/ethereum/go-ethereum/signer/core/apitypes"
"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 = "6.1.0"
// InternalAPIVersion -- see intapi_changelog.md
InternalAPIVersion = "7.0.1"
)
// 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 apitypes.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 apitypes.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)
// SignGnosisSafeTransaction signs/confirms a gnosis-safe multisig transaction
SignGnosisSafeTx(ctx context.Context, signerAddress common.MixedcaseAddress, gnosisTx GnosisSafeTx, methodSelector *string) (*GnosisSafeTx, 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)
}
// Validator defines the methods required to validate a transaction against some
// sanity defaults as well as any underlying 4byte method database.
//
// Use fourbyte.Database as an implementation. It is separated out of this package
// to allow pieces of the signer package to be used without having to load the
// 7MB embedded 4byte dump.
type Validator interface {
// ValidateTransaction does a number of checks on the supplied transaction, and
// returns either a list of warnings, or an error (indicating that the transaction
// should be immediately rejected).
ValidateTransaction(selector *string, tx *apitypes.SendTxArgs) (*apitypes.ValidationMessages, error)
}
// 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, scpath string) *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 (HID version)
if trezorhub, err := usbwallet.NewTrezorHubWithHID(); err != nil {
log.Warn(fmt.Sprintf("Failed to start HID Trezor hub, disabling: %v", err))
} else {
backends = append(backends, trezorhub)
log.Debug("Trezor support enabled via HID")
}
// Start a USB hub for Trezor hardware wallets (WebUSB version)
if trezorhub, err := usbwallet.NewTrezorHubWithWebUSB(); err != nil {
log.Warn(fmt.Sprintf("Failed to start WebUSB Trezor hub, disabling: %v", err))
} else {
backends = append(backends, trezorhub)
log.Debug("Trezor support enabled via WebUSB")
}
}
// Start a smart card hub
if len(scpath) > 0 {
// Sanity check that the smartcard path is valid
fi, err := os.Stat(scpath)
if err != nil {
log.Info("Smartcard socket file missing, disabling", "err", err)
} else {
if fi.Mode()&os.ModeType != os.ModeSocket {
log.Error("Invalid smartcard socket file type", "path", scpath, "type", fi.Mode().String())
} else {
if schub, err := scwallet.NewHub(scpath, scwallet.Scheme, ksLocation); err != nil {
log.Warn(fmt.Sprintf("Failed to start smart card hub, disabling: %v", err))
} else {
backends = append(backends, schub)
}
}
}
}
// Clef doesn't allow insecure http account unlock.
return accounts.NewManager(&accounts.Config{InsecureUnlockAllowed: false}, backends...)
}
// MetadataFromContext extracts Metadata from a given context.Context
func MetadataFromContext(ctx context.Context) Metadata {
info := rpc.PeerInfoFromContext(ctx)
m := Metadata{"NA", "NA", "NA", "", ""} // batman
if info.Transport != "" {
if info.Transport == "http" {
m.Scheme = info.HTTP.Version
}
m.Scheme = info.Transport
}
if info.RemoteAddr != "" {
m.Remote = info.RemoteAddr
}
if info.HTTP.Host != "" {
m.Local = info.HTTP.Host
}
m.Origin = info.HTTP.Origin
m.UserAgent = info.HTTP.UserAgent
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 apitypes.SendTxArgs `json:"transaction"`
Callinfo []apitypes.ValidationInfo `json:"call_info"`
Meta Metadata `json:"meta"`
}
// SignTxResponse result from SignTxRequest
SignTxResponse struct {
//The UI may make changes to the TX
Transaction apitypes.SendTxArgs `json:"transaction"`
Approved bool `json:"approved"`
}
SignDataRequest struct {
ContentType string `json:"content_type"`
Address common.MixedcaseAddress `json:"address"`
Rawdata []byte `json:"raw_data"`
Messages []*apitypes.NameValueType `json:"messages"`
Callinfo []apitypes.ValidationInfo `json:"call_info"`
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, validator Validator, 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, validator, !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() {
eventCh := make(chan accounts.WalletEvent, 16)
am := api.am
am.Subscribe(eventCh)
// 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())
}
}
}
go api.derivationLoop(eventCh)
}
// derivationLoop listens for wallet events
func (api *SignerAPI) derivationLoop(events chan accounts.WalletEvent) {
// 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)
var derive = func(limit int, next func() accounts.DerivationPath) {
// Derive first N accounts, hardcoded for now
for i := 0; i < limit; i++ {
path := next()
if acc, err := event.Wallet.Derive(path, true); err != nil {
log.Warn("Account derivation failed", "error", err)
} else {
log.Info("Derived account", "address", acc.Address, "path", path)
}
}
}
log.Info("Deriving default paths")
derive(numberOfAccountsToDerive, accounts.DefaultIterator(accounts.DefaultBaseDerivationPath))
if event.Wallet.URL().Scheme == "ledger" {
log.Info("Deriving ledger legacy paths")
derive(numberOfAccountsToDerive, accounts.DefaultIterator(accounts.LegacyLedgerBaseDerivationPath))
log.Info("Deriving ledger live paths")
// For ledger live, since it's based off the same (DefaultBaseDerivationPath)
// as one we've already used, we need to step it forward one step to avoid
// hitting the same path again
nextFn := accounts.LedgerLiveIterator(accounts.DefaultBaseDerivationPath)
nextFn()
derive(numberOfAccountsToDerive, nextFn)
}
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 = make([]accounts.Account, 0)
// accs is initialized as empty list, not nil. We use 'nil' to signal
// rejection, as opposed to an empty list.
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) {
if be := api.am.Backends(keystore.KeyStoreType); 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
}
return api.newAccount()
}
// newAccount is the internal method to create a new account. It should be used
// _after_ user-approval has been obtained
func (api *SignerAPI) newAccount() (common.Address, error) {
be := api.am.Backends(keystore.KeyStoreType)
if len(be) == 0 {
return common.Address{}, errors.New("password based accounts not supported")
}
// 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)
log.Info("Your new key was generated", "address", acc.Address)
log.Warn("Please backup your key file!", "path", acc.URL.Path)
log.Warn("Please remember your password!")
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 {
var intPtrModified = func(a, b *hexutil.Big) bool {
aBig := (*big.Int)(a)
bBig := (*big.Int)(b)
if aBig != nil && bBig != nil {
return aBig.Cmp(bBig) != 0
}
// One or both of them are nil
return a != b
}
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 a, b := original.Transaction.GasPrice, new.Transaction.GasPrice; intPtrModified(a, b) {
log.Info("GasPrice changed by UI", "was", a, "is", b)
modified = true
}
if a, b := original.Transaction.MaxPriorityFeePerGas, new.Transaction.MaxPriorityFeePerGas; intPtrModified(a, b) {
log.Info("maxPriorityFeePerGas changed by UI", "was", a, "is", b)
modified = true
}
if a, b := original.Transaction.MaxFeePerGas, new.Transaction.MaxFeePerGas; intPtrModified(a, b) {
log.Info("maxFeePerGas changed by UI", "was", a, "is", b)
modified = true
}
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, error) {
return api.credentials.Get(address.Hex())
}
func (api *SignerAPI) lookupOrQueryPassword(address common.Address, title, prompt string) (string, error) {
// Look up the password and return if available
if pw, err := api.lookupPassword(address); err == nil {
return pw, nil
}
// Password unavailable, request it from the user
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 apitypes.SendTxArgs, methodSelector *string) (*ethapi.SignTransactionResult, error) {
var (
err error
result SignTxResponse
)
msgs, err := api.validator.ValidateTransaction(methodSelector, &args)
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
}
}
if args.ChainID != nil {
requestedChainId := (*big.Int)(args.ChainID)
if api.chainID.Cmp(requestedChainId) != 0 {
log.Error("Signing request with wrong chain id", "requested", requestedChainId, "configured", api.chainID)
return nil, fmt.Errorf("requested chainid %d does not match the configuration of the signer",
requestedChainId)
}
}
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
}
data, err := signedTx.MarshalBinary()
if err != nil {
return nil, err
}
response := ethapi.SignTransactionResult{Raw: data, Tx: signedTx}
// Finally, send the signed tx to the UI
api.UI.OnApprovedTx(response)
// ...and to the external caller
return &response, nil
}
func (api *SignerAPI) SignGnosisSafeTx(ctx context.Context, signerAddress common.MixedcaseAddress, gnosisTx GnosisSafeTx, methodSelector *string) (*GnosisSafeTx, error) {
// Do the usual validations, but on the last-stage transaction
args := gnosisTx.ArgsForValidation()
msgs, err := api.validator.ValidateTransaction(methodSelector, args)
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
}
}
typedData := gnosisTx.ToTypedData()
signature, preimage, err := api.signTypedData(ctx, signerAddress, typedData, msgs)
if err != nil {
return nil, err
}
checkSummedSender, _ := common.NewMixedcaseAddressFromString(signerAddress.Address().Hex())
gnosisTx.Signature = signature
gnosisTx.SafeTxHash = common.BytesToHash(preimage)
gnosisTx.Sender = *checkSummedSender // Must be checksumed to be accepted by relay
return &gnosisTx, 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
}