1 files changed, 362 insertions, 0 deletions
diff --git a/accounts/keystore/keystore.go b/accounts/keystore/keystore.go
new file mode 100644
index 000000000..d125f7d62
--- /dev/null
+++ b/accounts/keystore/keystore.go
@@ -0,0 +1,362 @@
+// Copyright 2015 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/ethereum/go-ethereum/accounts"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
+)
+
+var (
+	ErrNeedPasswordOrUnlock = accounts.NewAuthNeededError("password or unlock")
+	ErrNoMatch              = errors.New("no key for given address or file")
+	ErrDecrypt              = errors.New("could not decrypt key with given passphrase")
+)
+
+// BackendType can be used to query the account manager for encrypted keystores.
+var BackendType = reflect.TypeOf(new(KeyStore))
+
+// KeyStore manages a key storage directory on disk.
+type KeyStore struct {
+	cache    *addressCache
+	keyStore keyStore
+	mu       sync.RWMutex
+	unlocked map[common.Address]*unlocked
+}
+
+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{keyStore: &keyStorePassphrase{keydir, scryptN, scryptP}}
+	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{keyStore: &keyStorePlain{keydir}}
+	ks.init(keydir)
+	return ks
+}
+
+func (ks *KeyStore) init(keydir string) {
+	ks.unlocked = make(map[common.Address]*unlocked)
+	ks.cache = newAddrCache(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()
+	})
+}
+
+// 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)
+	if err == nil {
+		ks.cache.delete(a)
+	}
+	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, ErrNeedPasswordOrUnlock
+	}
+	// 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, ErrNeedPasswordOrUnlock
+	}
+	// 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
+		} else {
+			// 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.keyStore.GetKey(a.Address, a.URL, 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.keyStore, 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)
+	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.keyStore.(*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: ks.keyStore.JoinPath(keyFileName(key.Address))}
+	if err := ks.keyStore.StoreKey(a.URL, key, passphrase); err != nil {
+		return accounts.Account{}, err
+	}
+	ks.cache.add(a)
+	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.keyStore.StoreKey(a.URL, 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.keyStore, keyJSON, passphrase)
+	if err != nil {
+		return a, err
+	}
+	ks.cache.add(a)
+	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
+	}
+}