prysm-pulse/validator/keymanager/v2/derived/derived.go
Raul Jordan 18f8578d73
Derived Keymanager Has No Need to Store Accounts to Disk (#6790)
* tests pass
* Merge branch 'master' into derive-no-store
* Merge refs/heads/master into derive-no-store
* gaz
* Merge branch 'derive-no-store' of github.com:prysmaticlabs/prysm into derive-no-store
* Merge refs/heads/master into derive-no-store
2020-07-30 23:23:18 +00:00

422 lines
16 KiB
Go

package derived
import (
"context"
"encoding/json"
"fmt"
"io"
"io/ioutil"
"path"
"sync"
"github.com/google/uuid"
"github.com/pkg/errors"
"github.com/prysmaticlabs/go-ssz"
validatorpb "github.com/prysmaticlabs/prysm/proto/validator/accounts/v2"
"github.com/prysmaticlabs/prysm/shared/bls"
"github.com/prysmaticlabs/prysm/shared/bytesutil"
"github.com/prysmaticlabs/prysm/shared/depositutil"
"github.com/prysmaticlabs/prysm/shared/petnames"
"github.com/prysmaticlabs/prysm/shared/rand"
"github.com/prysmaticlabs/prysm/validator/accounts/v2/iface"
"github.com/sirupsen/logrus"
"github.com/tyler-smith/go-bip39"
util "github.com/wealdtech/go-eth2-util"
keystorev4 "github.com/wealdtech/go-eth2-wallet-encryptor-keystorev4"
)
var log = logrus.WithField("prefix", "derived-keymanager-v2")
const (
// EIPVersion used by this derived keymanager implementation.
EIPVersion = "EIP-2334"
// WithdrawalKeyDerivationPathTemplate defining the hierarchical path for withdrawal
// keys for Prysm eth2 validators. According to EIP-2334, the format is as follows:
// m / purpose / coin_type / account_index / withdrawal_key
WithdrawalKeyDerivationPathTemplate = "m/12381/3600/%d/0"
// ValidatingKeyDerivationPathTemplate defining the hierarchical path for validating
// keys for Prysm eth2 validators. According to EIP-2334, the format is as follows:
// m / purpose / coin_type / account_index / withdrawal_key / validating_key
ValidatingKeyDerivationPathTemplate = "m/12381/3600/%d/0/0"
// EncryptedSeedFileName for persisting a wallet's seed when using a derived keymanager.
EncryptedSeedFileName = "seed.encrypted.json"
)
// Config for a derived keymanager.
type Config struct {
DerivedPathStructure string
DerivedEIPNumber string
}
// Keymanager implementation for derived, HD keymanager using EIP-2333 and EIP-2334.
type Keymanager struct {
wallet iface.Wallet
cfg *Config
mnemonicGenerator SeedPhraseFactory
keysCache map[[48]byte]bls.SecretKey
lock sync.RWMutex
seedCfg *SeedConfig
seed []byte
walletPassword string
}
// SeedConfig json file representation as a Go struct.
type SeedConfig struct {
Crypto map[string]interface{} `json:"crypto"`
ID string `json:"uuid"`
NextAccount uint64 `json:"next_account"`
Version uint `json:"version"`
Name string `json:"name"`
}
// DefaultConfig for a derived keymanager implementation.
func DefaultConfig() *Config {
return &Config{
DerivedPathStructure: "m / purpose / coin_type / account_index / withdrawal_key / validating_key",
DerivedEIPNumber: EIPVersion,
}
}
// NewKeymanager instantiates a new derived keymanager from configuration options.
func NewKeymanager(
ctx context.Context,
wallet iface.Wallet,
cfg *Config,
skipMnemonicConfirm bool,
password string,
) (*Keymanager, error) {
seedConfigFile, err := wallet.ReadEncryptedSeedFromDisk(ctx)
if err != nil {
return nil, errors.Wrap(err, "could not read encrypted seed file from disk")
}
enc, err := ioutil.ReadAll(seedConfigFile)
if err != nil {
return nil, errors.Wrap(err, "could not read seed configuration file contents")
}
defer func() {
if err := seedConfigFile.Close(); err != nil {
log.Errorf("Could not close keymanager config file: %v", err)
}
}()
seedConfig := &SeedConfig{}
if err := json.Unmarshal(enc, seedConfig); err != nil {
return nil, errors.Wrap(err, "could not unmarshal seed configuration")
}
decryptor := keystorev4.New()
seed, err := decryptor.Decrypt(seedConfig.Crypto, password)
if err != nil {
return nil, errors.Wrap(err, "could not decrypt seed configuration with password")
}
k := &Keymanager{
wallet: wallet,
cfg: cfg,
mnemonicGenerator: &EnglishMnemonicGenerator{
skipMnemonicConfirm: skipMnemonicConfirm,
},
seedCfg: seedConfig,
seed: seed,
walletPassword: password,
keysCache: make(map[[48]byte]bls.SecretKey),
}
// We initialize a cache of public key -> secret keys
// used to retrieve secrets keys for the accounts via the unlocked wallet.
// This cache is needed to process Sign requests using a validating public key.
if err := k.initializeSecretKeysCache(); err != nil {
return nil, errors.Wrap(err, "could not initialize secret keys cache")
}
return k, nil
}
// UnmarshalConfigFile attempts to JSON unmarshal a derived keymanager
// configuration file into the *Config{} struct.
func UnmarshalConfigFile(r io.ReadCloser) (*Config, error) {
enc, err := ioutil.ReadAll(r)
if err != nil {
return nil, err
}
defer func() {
if err := r.Close(); err != nil {
log.Errorf("Could not close keymanager config file: %v", err)
}
}()
cfg := &Config{}
if err := json.Unmarshal(enc, cfg); err != nil {
return nil, err
}
return cfg, nil
}
// MarshalConfigFile returns a marshaled configuration file for a keymanager.
func MarshalConfigFile(ctx context.Context, cfg *Config) ([]byte, error) {
return json.MarshalIndent(cfg, "", "\t")
}
// InitializeWalletSeedFile creates a new, encrypted seed using a password input
// and persists its encrypted file metadata to disk under the wallet path.
func InitializeWalletSeedFile(ctx context.Context, password string, skipMnemonicConfirm bool) (*SeedConfig, error) {
mnemonicRandomness := make([]byte, 32)
if _, err := rand.NewGenerator().Read(mnemonicRandomness); err != nil {
return nil, errors.Wrap(err, "could not initialize mnemonic source of randomness")
}
m := &EnglishMnemonicGenerator{
skipMnemonicConfirm: skipMnemonicConfirm,
}
phrase, err := m.Generate(mnemonicRandomness)
if err != nil {
return nil, errors.Wrap(err, "could not generate wallet seed")
}
if err := m.ConfirmAcknowledgement(phrase); err != nil {
return nil, errors.Wrap(err, "could not confirm mnemonic acknowledgement")
}
walletSeed := bip39.NewSeed(phrase, "")
encryptor := keystorev4.New()
cryptoFields, err := encryptor.Encrypt(walletSeed, password)
if err != nil {
return nil, errors.Wrap(err, "could not encrypt seed phrase into keystore")
}
id, err := uuid.NewRandom()
if err != nil {
return nil, errors.Wrap(err, "could not generate unique UUID")
}
return &SeedConfig{
Crypto: cryptoFields,
ID: id.String(),
NextAccount: 0,
Version: encryptor.Version(),
Name: encryptor.Name(),
}, nil
}
// SeedFileFromMnemonic uses the provided mnemonic seed phrase to generate the
// appropriate seed file for recovering a derived wallets.
func SeedFileFromMnemonic(ctx context.Context, mnemonic string, password string) (*SeedConfig, error) {
if ok := bip39.IsMnemonicValid(mnemonic); !ok {
return nil, bip39.ErrInvalidMnemonic
}
walletSeed := bip39.NewSeed(mnemonic, "")
encryptor := keystorev4.New()
cryptoFields, err := encryptor.Encrypt(walletSeed, password)
if err != nil {
return nil, errors.Wrap(err, "could not encrypt seed phrase into keystore")
}
id, err := uuid.NewRandom()
if err != nil {
return nil, errors.Wrap(err, "could not generate unique UUID")
}
return &SeedConfig{
Crypto: cryptoFields,
ID: id.String(),
NextAccount: 0,
Version: encryptor.Version(),
Name: encryptor.Name(),
}, nil
}
// MarshalEncryptedSeedFile json encodes the seed configuration for a derived keymanager.
func MarshalEncryptedSeedFile(ctx context.Context, seedCfg *SeedConfig) ([]byte, error) {
return json.MarshalIndent(seedCfg, "", "\t")
}
// Config returns the derived keymanager configuration.
func (dr *Keymanager) Config() *Config {
return dr.cfg
}
// NextAccountNumber managed by the derived keymanager.
func (dr *Keymanager) NextAccountNumber(ctx context.Context) uint64 {
return dr.seedCfg.NextAccount
}
// ValidatingAccountNames for the derived keymanager.
func (dr *Keymanager) ValidatingAccountNames(ctx context.Context) ([]string, error) {
names := make([]string, 0)
for i := uint64(0); i < dr.seedCfg.NextAccount; i++ {
validatingKeyPath := fmt.Sprintf(ValidatingKeyDerivationPathTemplate, i)
validatingKey, err := util.PrivateKeyFromSeedAndPath(dr.seed, validatingKeyPath)
if err != nil {
return nil, errors.Wrap(err, "could not derive validating key")
}
names = append(names, petnames.DeterministicName(validatingKey.Marshal(), "-"))
}
return names, nil
}
// CreateAccount for a derived keymanager implementation. This utilizes
// the EIP-2335 keystore standard for BLS12-381 keystores. It uses the EIP-2333 and EIP-2334
// for hierarchical derivation of BLS secret keys and a common derivation path structure for
// persisting accounts to disk. Each account stores the generated keystore.json file.
// The entire derived wallet seed phrase can be recovered from a BIP-39 english mnemonic.
func (dr *Keymanager) CreateAccount(ctx context.Context, logAccountInfo bool) (string, error) {
withdrawalKeyPath := fmt.Sprintf(WithdrawalKeyDerivationPathTemplate, dr.seedCfg.NextAccount)
validatingKeyPath := fmt.Sprintf(ValidatingKeyDerivationPathTemplate, dr.seedCfg.NextAccount)
withdrawalKey, err := util.PrivateKeyFromSeedAndPath(dr.seed, withdrawalKeyPath)
if err != nil {
return "", errors.Wrapf(err, "failed to create withdrawal key for account %d", dr.seedCfg.NextAccount)
}
validatingKey, err := util.PrivateKeyFromSeedAndPath(dr.seed, validatingKeyPath)
if err != nil {
return "", errors.Wrapf(err, "failed to create validating key for account %d", dr.seedCfg.NextAccount)
}
// Upon confirmation of the withdrawal key, proceed to display
// and write associated deposit data to disk.
blsValidatingKey, err := bls.SecretKeyFromBytes(validatingKey.Marshal())
if err != nil {
return "", err
}
blsWithdrawalKey, err := bls.SecretKeyFromBytes(withdrawalKey.Marshal())
if err != nil {
return "", err
}
_, depositData, err := depositutil.GenerateDepositTransaction(blsValidatingKey, blsWithdrawalKey)
if err != nil {
return "", errors.Wrap(err, "could not generate deposit transaction data")
}
// We write the ssz-encoded deposit data to disk as a .ssz file.
encodedDepositData, err := ssz.Marshal(depositData)
if err != nil {
return "", errors.Wrap(err, "could not marshal deposit data")
}
if logAccountInfo {
// Log the deposit transaction data to the user.
fmt.Printf(`
========================SSZ Deposit Data===============================
%#x
===================================================================`, encodedDepositData)
}
// Finally, write the account creation timestamps as a files.
newAccountNumber := dr.seedCfg.NextAccount
if logAccountInfo {
log.WithFields(logrus.Fields{
"accountNumber": newAccountNumber,
"withdrawalPublicKey": fmt.Sprintf("%#x", withdrawalKey.PublicKey().Marshal()),
"validatingPublicKey": fmt.Sprintf("%#x", validatingKey.PublicKey().Marshal()),
"withdrawalKeyPath": path.Join(dr.wallet.AccountsDir(), withdrawalKeyPath),
"validatingKeyPath": path.Join(dr.wallet.AccountsDir(), validatingKeyPath),
}).Info("Successfully created new validator account")
}
dr.seedCfg.NextAccount++
encodedCfg, err := MarshalEncryptedSeedFile(ctx, dr.seedCfg)
if err != nil {
return "", errors.Wrap(err, "could not marshal encrypted seed file")
}
if err := dr.wallet.WriteEncryptedSeedToDisk(ctx, encodedCfg); err != nil {
return "", errors.Wrap(err, "could not write encrypted seed file to disk")
}
return fmt.Sprintf("%d", newAccountNumber), nil
}
// Sign signs a message using a validator key.
func (dr *Keymanager) Sign(ctx context.Context, req *validatorpb.SignRequest) (bls.Signature, error) {
rawPubKey := req.PublicKey
if rawPubKey == nil {
return nil, errors.New("nil public key in request")
}
dr.lock.RLock()
defer dr.lock.RUnlock()
secretKey, ok := dr.keysCache[bytesutil.ToBytes48(rawPubKey)]
if !ok {
return nil, errors.New("no signing key found in keys cache")
}
return secretKey.Sign(req.SigningRoot), nil
}
// FetchValidatingPublicKeys fetches the list of validating public keys from the keymanager.
func (dr *Keymanager) FetchValidatingPublicKeys(ctx context.Context) ([][48]byte, error) {
// Return the public keys from the cache if they match the
// number of accounts from the wallet.
publicKeys := make([][48]byte, dr.seedCfg.NextAccount)
dr.lock.RLock()
defer dr.lock.RUnlock()
if dr.keysCache != nil && uint64(len(dr.keysCache)) == dr.seedCfg.NextAccount {
var i int
for k := range dr.keysCache {
publicKeys[i] = k
i++
}
return publicKeys, nil
}
for i := uint64(0); i < dr.seedCfg.NextAccount; i++ {
validatingKeyPath := fmt.Sprintf(ValidatingKeyDerivationPathTemplate, i)
validatingKey, err := util.PrivateKeyFromSeedAndPath(dr.seed, validatingKeyPath)
if err != nil {
return nil, errors.Wrapf(err, "failed to create validating key for account %d", i)
}
publicKeys = append(publicKeys, bytesutil.ToBytes48(validatingKey.PublicKey().Marshal()))
}
return publicKeys, nil
}
// FetchWithdrawalPublicKeys fetches the list of withdrawal public keys from keymanager
func (dr *Keymanager) FetchWithdrawalPublicKeys(ctx context.Context) ([][48]byte, error) {
publicKeys := make([][48]byte, 0)
for i := uint64(0); i < dr.seedCfg.NextAccount; i++ {
withdrawalKeyPath := fmt.Sprintf(WithdrawalKeyDerivationPathTemplate, i)
withdrawalKey, err := util.PrivateKeyFromSeedAndPath(dr.seed, withdrawalKeyPath)
if err != nil {
return nil, errors.Wrapf(err, "failed to create validating key for account %d", i)
}
publicKeys = append(publicKeys, bytesutil.ToBytes48(withdrawalKey.PublicKey().Marshal()))
}
return publicKeys, nil
}
// DepositDataForAccount with a given index returns and ssz-encoded deposit data object.
func (dr *Keymanager) DepositDataForAccount(accountIndex uint64) ([]byte, error) {
withdrawalKeyPath := fmt.Sprintf(WithdrawalKeyDerivationPathTemplate, accountIndex)
validatingKeyPath := fmt.Sprintf(ValidatingKeyDerivationPathTemplate, accountIndex)
withdrawalKey, err := util.PrivateKeyFromSeedAndPath(dr.seed, withdrawalKeyPath)
if err != nil {
return nil, errors.Wrapf(err, "failed to create withdrawal key for account %d", accountIndex)
}
validatingKey, err := util.PrivateKeyFromSeedAndPath(dr.seed, validatingKeyPath)
if err != nil {
return nil, errors.Wrapf(err, "failed to create validating key for account %d", accountIndex)
}
// Upon confirmation of the withdrawal key, proceed to display
// and write associated deposit data to disk.
blsValidatingKey, err := bls.SecretKeyFromBytes(validatingKey.Marshal())
if err != nil {
return nil, err
}
blsWithdrawalKey, err := bls.SecretKeyFromBytes(withdrawalKey.Marshal())
if err != nil {
return nil, err
}
_, depositData, err := depositutil.GenerateDepositTransaction(blsValidatingKey, blsWithdrawalKey)
if err != nil {
return nil, errors.Wrap(err, "could not generate deposit transaction data")
}
return ssz.Marshal(depositData)
}
func (dr *Keymanager) initializeSecretKeysCache() error {
dr.lock.Lock()
defer dr.lock.Unlock()
for i := uint64(0); i < dr.seedCfg.NextAccount; i++ {
validatingKeyPath := fmt.Sprintf(ValidatingKeyDerivationPathTemplate, i)
derivedKey, err := util.PrivateKeyFromSeedAndPath(dr.seed, validatingKeyPath)
if err != nil {
return errors.Wrapf(err, "failed to derive validating key for account %s", validatingKeyPath)
}
validatorSigningKey, err := bls.SecretKeyFromBytes(derivedKey.Marshal())
if err != nil {
return errors.Wrapf(
err,
"could not instantiate bls secret key from bytes for account: %s",
validatingKeyPath,
)
}
// Update a simple cache of public key -> secret key utilized
// for fast signing access in the keymanager.
dr.keysCache[bytesutil.ToBytes48(validatorSigningKey.PublicKey().Marshal())] = validatorSigningKey
}
return nil
}