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authorDeterminant <[email protected]>2020-06-28 14:47:41 -0400
committerDeterminant <[email protected]>2020-06-28 14:47:41 -0400
commitd235e2c6a5788ec4a6cff15a16f56b38a3876a0d (patch)
tree5f2727f7a50ee5840f889c82776d3a30a88dd59b /accounts/keystore/keystore.go
parent13ebd8bd9468e9d769d598b0ca2afb72ba78cb97 (diff)
...
Diffstat (limited to 'accounts/keystore/keystore.go')
-rw-r--r--accounts/keystore/keystore.go495
1 files changed, 495 insertions, 0 deletions
diff --git a/accounts/keystore/keystore.go b/accounts/keystore/keystore.go
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+++ b/accounts/keystore/keystore.go
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+// Copyright 2017 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 keystore implements encrypted storage of secp256k1 private keys.
+//
+// Keys are stored as encrypted JSON files according to the Web3 Secret Storage specification.
+// See https://github.com/ethereum/wiki/wiki/Web3-Secret-Storage-Definition for more information.
+package keystore
+
+import (
+ "crypto/ecdsa"
+ crand "crypto/rand"
+ "errors"
+ "fmt"
+ "math/big"
+ "os"
+ "path/filepath"
+ "reflect"
+ "runtime"
+ "sync"
+ "time"
+
+ "github.com/ava-labs/coreth/accounts"
+ "github.com/ava-labs/coreth/core/types"
+ "github.com/ava-labs/go-ethereum/common"
+ "github.com/ava-labs/go-ethereum/crypto"
+ "github.com/ava-labs/go-ethereum/event"
+)
+
+var (
+ ErrLocked = accounts.NewAuthNeededError("password or unlock")
+ ErrNoMatch = errors.New("no key for given address or file")
+ ErrDecrypt = errors.New("could not decrypt key with given password")
+)
+
+// KeyStoreType is the reflect type of a keystore backend.
+var KeyStoreType = reflect.TypeOf(&KeyStore{})
+
+// KeyStoreScheme is the protocol scheme prefixing account and wallet URLs.
+const KeyStoreScheme = "keystore"
+
+// Maximum time between wallet refreshes (if filesystem notifications don't work).
+const walletRefreshCycle = 3 * time.Second
+
+// KeyStore manages a key storage directory on disk.
+type KeyStore struct {
+ storage keyStore // Storage backend, might be cleartext or encrypted
+ cache *accountCache // In-memory account cache over the filesystem storage
+ changes chan struct{} // Channel receiving change notifications from the cache
+ unlocked map[common.Address]*unlocked // Currently unlocked account (decrypted private keys)
+
+ wallets []accounts.Wallet // Wallet wrappers around the individual key files
+ updateFeed event.Feed // Event feed to notify wallet additions/removals
+ updateScope event.SubscriptionScope // Subscription scope tracking current live listeners
+ updating bool // Whether the event notification loop is running
+
+ mu sync.RWMutex
+}
+
+type unlocked struct {
+ *Key
+ abort chan struct{}
+}
+
+// NewKeyStore creates a keystore for the given directory.
+func NewKeyStore(keydir string, scryptN, scryptP int) *KeyStore {
+ keydir, _ = filepath.Abs(keydir)
+ ks := &KeyStore{storage: &keyStorePassphrase{keydir, scryptN, scryptP, false}}
+ ks.init(keydir)
+ return ks
+}
+
+// NewPlaintextKeyStore creates a keystore for the given directory.
+// Deprecated: Use NewKeyStore.
+func NewPlaintextKeyStore(keydir string) *KeyStore {
+ keydir, _ = filepath.Abs(keydir)
+ ks := &KeyStore{storage: &keyStorePlain{keydir}}
+ ks.init(keydir)
+ return ks
+}
+
+func (ks *KeyStore) init(keydir string) {
+ // Lock the mutex since the account cache might call back with events
+ ks.mu.Lock()
+ defer ks.mu.Unlock()
+
+ // Initialize the set of unlocked keys and the account cache
+ ks.unlocked = make(map[common.Address]*unlocked)
+ ks.cache, ks.changes = newAccountCache(keydir)
+
+ // TODO: In order for this finalizer to work, there must be no references
+ // to ks. addressCache doesn't keep a reference but unlocked keys do,
+ // so the finalizer will not trigger until all timed unlocks have expired.
+ runtime.SetFinalizer(ks, func(m *KeyStore) {
+ m.cache.close()
+ })
+ // Create the initial list of wallets from the cache
+ accs := ks.cache.accounts()
+ ks.wallets = make([]accounts.Wallet, len(accs))
+ for i := 0; i < len(accs); i++ {
+ ks.wallets[i] = &keystoreWallet{account: accs[i], keystore: ks}
+ }
+}
+
+// Wallets implements accounts.Backend, returning all single-key wallets from the
+// keystore directory.
+func (ks *KeyStore) Wallets() []accounts.Wallet {
+ // Make sure the list of wallets is in sync with the account cache
+ ks.refreshWallets()
+
+ ks.mu.RLock()
+ defer ks.mu.RUnlock()
+
+ cpy := make([]accounts.Wallet, len(ks.wallets))
+ copy(cpy, ks.wallets)
+ return cpy
+}
+
+// refreshWallets retrieves the current account list and based on that does any
+// necessary wallet refreshes.
+func (ks *KeyStore) refreshWallets() {
+ // Retrieve the current list of accounts
+ ks.mu.Lock()
+ accs := ks.cache.accounts()
+
+ // Transform the current list of wallets into the new one
+ var (
+ wallets = make([]accounts.Wallet, 0, len(accs))
+ events []accounts.WalletEvent
+ )
+
+ for _, account := range accs {
+ // Drop wallets while they were in front of the next account
+ for len(ks.wallets) > 0 && ks.wallets[0].URL().Cmp(account.URL) < 0 {
+ events = append(events, accounts.WalletEvent{Wallet: ks.wallets[0], Kind: accounts.WalletDropped})
+ ks.wallets = ks.wallets[1:]
+ }
+ // If there are no more wallets or the account is before the next, wrap new wallet
+ if len(ks.wallets) == 0 || ks.wallets[0].URL().Cmp(account.URL) > 0 {
+ wallet := &keystoreWallet{account: account, keystore: ks}
+
+ events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletArrived})
+ wallets = append(wallets, wallet)
+ continue
+ }
+ // If the account is the same as the first wallet, keep it
+ if ks.wallets[0].Accounts()[0] == account {
+ wallets = append(wallets, ks.wallets[0])
+ ks.wallets = ks.wallets[1:]
+ continue
+ }
+ }
+ // Drop any leftover wallets and set the new batch
+ for _, wallet := range ks.wallets {
+ events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletDropped})
+ }
+ ks.wallets = wallets
+ ks.mu.Unlock()
+
+ // Fire all wallet events and return
+ for _, event := range events {
+ ks.updateFeed.Send(event)
+ }
+}
+
+// Subscribe implements accounts.Backend, creating an async subscription to
+// receive notifications on the addition or removal of keystore wallets.
+func (ks *KeyStore) Subscribe(sink chan<- accounts.WalletEvent) event.Subscription {
+ // We need the mutex to reliably start/stop the update loop
+ ks.mu.Lock()
+ defer ks.mu.Unlock()
+
+ // Subscribe the caller and track the subscriber count
+ sub := ks.updateScope.Track(ks.updateFeed.Subscribe(sink))
+
+ // Subscribers require an active notification loop, start it
+ if !ks.updating {
+ ks.updating = true
+ go ks.updater()
+ }
+ return sub
+}
+
+// updater is responsible for maintaining an up-to-date list of wallets stored in
+// the keystore, and for firing wallet addition/removal events. It listens for
+// account change events from the underlying account cache, and also periodically
+// forces a manual refresh (only triggers for systems where the filesystem notifier
+// is not running).
+func (ks *KeyStore) updater() {
+ for {
+ // Wait for an account update or a refresh timeout
+ select {
+ case <-ks.changes:
+ case <-time.After(walletRefreshCycle):
+ }
+ // Run the wallet refresher
+ ks.refreshWallets()
+
+ // If all our subscribers left, stop the updater
+ ks.mu.Lock()
+ if ks.updateScope.Count() == 0 {
+ ks.updating = false
+ ks.mu.Unlock()
+ return
+ }
+ ks.mu.Unlock()
+ }
+}
+
+// HasAddress reports whether a key with the given address is present.
+func (ks *KeyStore) HasAddress(addr common.Address) bool {
+ return ks.cache.hasAddress(addr)
+}
+
+// Accounts returns all key files present in the directory.
+func (ks *KeyStore) Accounts() []accounts.Account {
+ return ks.cache.accounts()
+}
+
+// Delete deletes the key matched by account if the passphrase is correct.
+// If the account contains no filename, the address must match a unique key.
+func (ks *KeyStore) Delete(a accounts.Account, passphrase string) error {
+ // Decrypting the key isn't really necessary, but we do
+ // it anyway to check the password and zero out the key
+ // immediately afterwards.
+ a, key, err := ks.getDecryptedKey(a, passphrase)
+ if key != nil {
+ zeroKey(key.PrivateKey)
+ }
+ if err != nil {
+ return err
+ }
+ // The order is crucial here. The key is dropped from the
+ // cache after the file is gone so that a reload happening in
+ // between won't insert it into the cache again.
+ err = os.Remove(a.URL.Path)
+ if err == nil {
+ ks.cache.delete(a)
+ ks.refreshWallets()
+ }
+ return err
+}
+
+// SignHash calculates a ECDSA signature for the given hash. The produced
+// signature is in the [R || S || V] format where V is 0 or 1.
+func (ks *KeyStore) SignHash(a accounts.Account, hash []byte) ([]byte, error) {
+ // Look up the key to sign with and abort if it cannot be found
+ ks.mu.RLock()
+ defer ks.mu.RUnlock()
+
+ unlockedKey, found := ks.unlocked[a.Address]
+ if !found {
+ return nil, ErrLocked
+ }
+ // Sign the hash using plain ECDSA operations
+ return crypto.Sign(hash, unlockedKey.PrivateKey)
+}
+
+// SignTx signs the given transaction with the requested account.
+func (ks *KeyStore) SignTx(a accounts.Account, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
+ // Look up the key to sign with and abort if it cannot be found
+ ks.mu.RLock()
+ defer ks.mu.RUnlock()
+
+ unlockedKey, found := ks.unlocked[a.Address]
+ if !found {
+ return nil, ErrLocked
+ }
+ // Depending on the presence of the chain ID, sign with EIP155 or homestead
+ if chainID != nil {
+ return types.SignTx(tx, types.NewEIP155Signer(chainID), unlockedKey.PrivateKey)
+ }
+ return types.SignTx(tx, types.HomesteadSigner{}, unlockedKey.PrivateKey)
+}
+
+// SignHashWithPassphrase signs hash if the private key matching the given address
+// can be decrypted with the given passphrase. The produced signature is in the
+// [R || S || V] format where V is 0 or 1.
+func (ks *KeyStore) SignHashWithPassphrase(a accounts.Account, passphrase string, hash []byte) (signature []byte, err error) {
+ _, key, err := ks.getDecryptedKey(a, passphrase)
+ if err != nil {
+ return nil, err
+ }
+ defer zeroKey(key.PrivateKey)
+ return crypto.Sign(hash, key.PrivateKey)
+}
+
+// SignTxWithPassphrase signs the transaction if the private key matching the
+// given address can be decrypted with the given passphrase.
+func (ks *KeyStore) SignTxWithPassphrase(a accounts.Account, passphrase string, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
+ _, key, err := ks.getDecryptedKey(a, passphrase)
+ if err != nil {
+ return nil, err
+ }
+ defer zeroKey(key.PrivateKey)
+
+ // Depending on the presence of the chain ID, sign with EIP155 or homestead
+ if chainID != nil {
+ return types.SignTx(tx, types.NewEIP155Signer(chainID), key.PrivateKey)
+ }
+ return types.SignTx(tx, types.HomesteadSigner{}, key.PrivateKey)
+}
+
+// Unlock unlocks the given account indefinitely.
+func (ks *KeyStore) Unlock(a accounts.Account, passphrase string) error {
+ return ks.TimedUnlock(a, passphrase, 0)
+}
+
+// Lock removes the private key with the given address from memory.
+func (ks *KeyStore) Lock(addr common.Address) error {
+ ks.mu.Lock()
+ if unl, found := ks.unlocked[addr]; found {
+ ks.mu.Unlock()
+ ks.expire(addr, unl, time.Duration(0)*time.Nanosecond)
+ } else {
+ ks.mu.Unlock()
+ }
+ return nil
+}
+
+// TimedUnlock unlocks the given account with the passphrase. The account
+// stays unlocked for the duration of timeout. A timeout of 0 unlocks the account
+// until the program exits. The account must match a unique key file.
+//
+// If the account address is already unlocked for a duration, TimedUnlock extends or
+// shortens the active unlock timeout. If the address was previously unlocked
+// indefinitely the timeout is not altered.
+func (ks *KeyStore) TimedUnlock(a accounts.Account, passphrase string, timeout time.Duration) error {
+ a, key, err := ks.getDecryptedKey(a, passphrase)
+ if err != nil {
+ return err
+ }
+
+ ks.mu.Lock()
+ defer ks.mu.Unlock()
+ u, found := ks.unlocked[a.Address]
+ if found {
+ if u.abort == nil {
+ // The address was unlocked indefinitely, so unlocking
+ // it with a timeout would be confusing.
+ zeroKey(key.PrivateKey)
+ return nil
+ }
+ // Terminate the expire goroutine and replace it below.
+ close(u.abort)
+ }
+ if timeout > 0 {
+ u = &unlocked{Key: key, abort: make(chan struct{})}
+ go ks.expire(a.Address, u, timeout)
+ } else {
+ u = &unlocked{Key: key}
+ }
+ ks.unlocked[a.Address] = u
+ return nil
+}
+
+// Find resolves the given account into a unique entry in the keystore.
+func (ks *KeyStore) Find(a accounts.Account) (accounts.Account, error) {
+ ks.cache.maybeReload()
+ ks.cache.mu.Lock()
+ a, err := ks.cache.find(a)
+ ks.cache.mu.Unlock()
+ return a, err
+}
+
+func (ks *KeyStore) getDecryptedKey(a accounts.Account, auth string) (accounts.Account, *Key, error) {
+ a, err := ks.Find(a)
+ if err != nil {
+ return a, nil, err
+ }
+ key, err := ks.storage.GetKey(a.Address, a.URL.Path, auth)
+ return a, key, err
+}
+
+func (ks *KeyStore) expire(addr common.Address, u *unlocked, timeout time.Duration) {
+ t := time.NewTimer(timeout)
+ defer t.Stop()
+ select {
+ case <-u.abort:
+ // just quit
+ case <-t.C:
+ ks.mu.Lock()
+ // only drop if it's still the same key instance that dropLater
+ // was launched with. we can check that using pointer equality
+ // because the map stores a new pointer every time the key is
+ // unlocked.
+ if ks.unlocked[addr] == u {
+ zeroKey(u.PrivateKey)
+ delete(ks.unlocked, addr)
+ }
+ ks.mu.Unlock()
+ }
+}
+
+// NewAccount generates a new key and stores it into the key directory,
+// encrypting it with the passphrase.
+func (ks *KeyStore) NewAccount(passphrase string) (accounts.Account, error) {
+ _, account, err := storeNewKey(ks.storage, crand.Reader, passphrase)
+ if err != nil {
+ return accounts.Account{}, err
+ }
+ // Add the account to the cache immediately rather
+ // than waiting for file system notifications to pick it up.
+ ks.cache.add(account)
+ ks.refreshWallets()
+ return account, nil
+}
+
+// Export exports as a JSON key, encrypted with newPassphrase.
+func (ks *KeyStore) Export(a accounts.Account, passphrase, newPassphrase string) (keyJSON []byte, err error) {
+ _, key, err := ks.getDecryptedKey(a, passphrase)
+ if err != nil {
+ return nil, err
+ }
+ var N, P int
+ if store, ok := ks.storage.(*keyStorePassphrase); ok {
+ N, P = store.scryptN, store.scryptP
+ } else {
+ N, P = StandardScryptN, StandardScryptP
+ }
+ return EncryptKey(key, newPassphrase, N, P)
+}
+
+// Import stores the given encrypted JSON key into the key directory.
+func (ks *KeyStore) Import(keyJSON []byte, passphrase, newPassphrase string) (accounts.Account, error) {
+ key, err := DecryptKey(keyJSON, passphrase)
+ if key != nil && key.PrivateKey != nil {
+ defer zeroKey(key.PrivateKey)
+ }
+ if err != nil {
+ return accounts.Account{}, err
+ }
+ return ks.importKey(key, newPassphrase)
+}
+
+// ImportECDSA stores the given key into the key directory, encrypting it with the passphrase.
+func (ks *KeyStore) ImportECDSA(priv *ecdsa.PrivateKey, passphrase string) (accounts.Account, error) {
+ key := newKeyFromECDSA(priv)
+ if ks.cache.hasAddress(key.Address) {
+ return accounts.Account{}, fmt.Errorf("account already exists")
+ }
+ return ks.importKey(key, passphrase)
+}
+
+func (ks *KeyStore) importKey(key *Key, passphrase string) (accounts.Account, error) {
+ a := accounts.Account{Address: key.Address, URL: accounts.URL{Scheme: KeyStoreScheme, Path: ks.storage.JoinPath(keyFileName(key.Address))}}
+ if err := ks.storage.StoreKey(a.URL.Path, key, passphrase); err != nil {
+ return accounts.Account{}, err
+ }
+ ks.cache.add(a)
+ ks.refreshWallets()
+ return a, nil
+}
+
+// Update changes the passphrase of an existing account.
+func (ks *KeyStore) Update(a accounts.Account, passphrase, newPassphrase string) error {
+ a, key, err := ks.getDecryptedKey(a, passphrase)
+ if err != nil {
+ return err
+ }
+ return ks.storage.StoreKey(a.URL.Path, key, newPassphrase)
+}
+
+// ImportPreSaleKey decrypts the given Ethereum presale wallet and stores
+// a key file in the key directory. The key file is encrypted with the same passphrase.
+func (ks *KeyStore) ImportPreSaleKey(keyJSON []byte, passphrase string) (accounts.Account, error) {
+ a, _, err := importPreSaleKey(ks.storage, keyJSON, passphrase)
+ if err != nil {
+ return a, err
+ }
+ ks.cache.add(a)
+ ks.refreshWallets()
+ return a, nil
+}
+
+// zeroKey zeroes a private key in memory.
+func zeroKey(k *ecdsa.PrivateKey) {
+ b := k.D.Bits()
+ for i := range b {
+ b[i] = 0
+ }
+}