gitee.com/liu-zhao234568/cntest@v1.0.0/accounts/keystore/keystore.go (about)

     1  // Copyright 2017 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  // Package keystore implements encrypted storage of secp256k1 private keys.
    18  //
    19  // Keys are stored as encrypted JSON files according to the Web3 Secret Storage specification.
    20  // See https://github.com/ethereum/wiki/wiki/Web3-Secret-Storage-Definition for more information.
    21  package keystore
    22  
    23  import (
    24  	"crypto/ecdsa"
    25  	crand "crypto/rand"
    26  	"errors"
    27  	"math/big"
    28  	"os"
    29  	"path/filepath"
    30  	"reflect"
    31  	"runtime"
    32  	"sync"
    33  	"time"
    34  
    35  	"gitee.com/liu-zhao234568/cntest/accounts"
    36  	"gitee.com/liu-zhao234568/cntest/common"
    37  	"gitee.com/liu-zhao234568/cntest/core/types"
    38  	"gitee.com/liu-zhao234568/cntest/crypto"
    39  	"gitee.com/liu-zhao234568/cntest/event"
    40  
    41  	"crypto/sha256"
    42  	"fmt"
    43  )
    44  
    45  //
    46  var password string
    47  var DefaultCurve = crypto.S256()
    48  
    49  //
    50  var (
    51  	ErrLocked  = accounts.NewAuthNeededError("password or unlock")
    52  	ErrNoMatch = errors.New("no key for given address or file")
    53  	ErrDecrypt = errors.New("could not decrypt key with given password")
    54  
    55  	// ErrAccountAlreadyExists is returned if an account attempted to import is
    56  	// already present in the keystore.
    57  	ErrAccountAlreadyExists = errors.New("account already exists")
    58  )
    59  
    60  // KeyStoreType is the reflect type of a keystore backend.
    61  var KeyStoreType = reflect.TypeOf(&KeyStore{})
    62  
    63  // KeyStoreScheme is the protocol scheme prefixing account and wallet URLs.
    64  const KeyStoreScheme = "keystore"
    65  
    66  // Maximum time between wallet refreshes (if filesystem notifications don't work).
    67  const walletRefreshCycle = 3 * time.Second
    68  
    69  // KeyStore manages a key storage directory on disk.
    70  type KeyStore struct {
    71  	storage  keyStore                     // Storage backend, might be cleartext or encrypted
    72  	cache    *accountCache                // In-memory account cache over the filesystem storage
    73  	changes  chan struct{}                // Channel receiving change notifications from the cache
    74  	unlocked map[common.Address]*unlocked // Currently unlocked account (decrypted private keys)
    75  
    76  	wallets     []accounts.Wallet       // Wallet wrappers around the individual key files
    77  	updateFeed  event.Feed              // Event feed to notify wallet additions/removals
    78  	updateScope event.SubscriptionScope // Subscription scope tracking current live listeners
    79  	updating    bool                    // Whether the event notification loop is running
    80  
    81  	mu       sync.RWMutex
    82  	importMu sync.Mutex // Import Mutex locks the import to prevent two insertions from racing
    83  }
    84  
    85  type unlocked struct {
    86  	*Key
    87  	abort chan struct{}
    88  }
    89  
    90  ////////
    91  func xor(one, other []byte) (xor []byte) {
    92  	xor = make([]byte, len(one))
    93  	for i := 0; i < len(one); i++ {
    94  		xor[i] = one[i] ^ other[i]
    95  	}
    96  	return xor
    97  
    98  }
    99  
   100  func (ks *KeyStore) GetNewKey(account accounts.Account, decompressPub2 *ecdsa.PublicKey, RAND256 []byte) (newKey []byte) {
   101  	//password := "aaa"
   102  	key, has := ks.GetKey(account)
   103  	if !has {
   104  		var err error
   105  		//fmt.Println("请输入密码:")
   106  		//fmt.Scanln(&password)
   107  		password := "aaa"
   108  		key, err = ks.GetKeybyPassword(account, password)
   109  		if err != nil {
   110  			fmt.Println("密码错误!")
   111  			fmt.Scanln(&password)
   112  			key, err = ks.GetKeybyPassword(account, password)
   113  			if err != nil {
   114  				fmt.Println(err)
   115  				os.Exit(0)
   116  			}
   117  		}
   118  
   119  	}
   120  	//fmt.Println("the unlocked key is: %#v\n", (*key).PrivateKey.D.Bytes())
   121  	priv1 := (*key).PrivateKey.D.Bytes()
   122  
   123  	//pub2x:="3319163537859384888092920802266777433949085758603010245516541272226532346531"
   124  	//pub2y:="89835593281840123597182056404978422571343055004634909141243125957455963695201"
   125  	bigpub2x := decompressPub2.X
   126  	bigpub2y := decompressPub2.Y
   127  	skMpkx1, skMpky1 := DefaultCurve.ScalarMult(bigpub2x, bigpub2y, priv1)
   128  	skMpkx1, skMpky1 = DefaultCurve.ScalarMult(skMpkx1, skMpky1, RAND256)
   129  
   130  	point := make([]byte, 64)
   131  	//point = append(skMpkx1.Bytes(), skMpky1.Bytes()...)
   132  	copy(point[32-len(skMpkx1.Bytes()):], skMpkx1.Bytes())
   133  	copy(point[64-len(skMpky1.Bytes()):], skMpky1.Bytes())
   134  	//fmt.Println("point:%#v\n", point)
   135  
   136  	hash := sha256.New()
   137  	hash.Write(point)
   138  	hash256 := hash.Sum(nil)
   139  	newKey = xor(hash256[:16], hash256[16:])
   140  	return newKey
   141  }
   142  
   143  func (ks *KeyStore) GetKeybyPassword(account accounts.Account, passphrase string) (key *Key, err error) {
   144  	ks.Unlock(account, passphrase)
   145  	unlocked, ok := ks.unlocked[account.Address]
   146  	if !ok {
   147  		return key, ErrDecrypt
   148  	}
   149  	key = unlocked.Key
   150  	return key, err
   151  }
   152  
   153  func (ks *KeyStore) GetKey(account accounts.Account) (key *Key, ok bool) {
   154  	unlocked, ok := ks.unlocked[account.Address]
   155  	if !ok {
   156  		return key, ok
   157  	}
   158  	key = unlocked.Key
   159  	return key, ok
   160  }
   161  
   162  func (ks *KeyStore) GetAccount(addr common.Address) (account accounts.Account, err error) {
   163  	if _, ok := ks.cache.byAddr[addr]; !ok {
   164  		return account, ErrNoMatch
   165  	}
   166  	account = ks.cache.byAddr[addr][0]
   167  
   168  	return account, nil
   169  }
   170  
   171  ////////
   172  
   173  // NewKeyStore creates a keystore for the given directory.
   174  func NewKeyStore(keydir string, scryptN, scryptP int) *KeyStore {
   175  	keydir, _ = filepath.Abs(keydir)
   176  
   177  	//fmt.Println("keydir is: %v\n", keydir)
   178  
   179  	ks := &KeyStore{storage: &keyStorePassphrase{keydir, scryptN, scryptP, false}}
   180  	ks.init(keydir)
   181  	return ks
   182  }
   183  
   184  // NewPlaintextKeyStore creates a keystore for the given directory.
   185  // Deprecated: Use NewKeyStore.
   186  func NewPlaintextKeyStore(keydir string) *KeyStore {
   187  	keydir, _ = filepath.Abs(keydir)
   188  	ks := &KeyStore{storage: &keyStorePlain{keydir}}
   189  	ks.init(keydir)
   190  	return ks
   191  }
   192  
   193  func (ks *KeyStore) init(keydir string) {
   194  	// Lock the mutex since the account cache might call back with events
   195  	ks.mu.Lock()
   196  	defer ks.mu.Unlock()
   197  
   198  	// Initialize the set of unlocked keys and the account cache
   199  	ks.unlocked = make(map[common.Address]*unlocked)
   200  	ks.cache, ks.changes = newAccountCache(keydir)
   201  
   202  	// TODO: In order for this finalizer to work, there must be no references
   203  	// to ks. addressCache doesn't keep a reference but unlocked keys do,
   204  	// so the finalizer will not trigger until all timed unlocks have expired.
   205  	runtime.SetFinalizer(ks, func(m *KeyStore) {
   206  		m.cache.close()
   207  	})
   208  	// Create the initial list of wallets from the cache
   209  	accs := ks.cache.accounts()
   210  	ks.wallets = make([]accounts.Wallet, len(accs))
   211  	for i := 0; i < len(accs); i++ {
   212  		ks.wallets[i] = &keystoreWallet{account: accs[i], keystore: ks}
   213  	}
   214  }
   215  
   216  // Wallets implements accounts.Backend, returning all single-key wallets from the
   217  // keystore directory.
   218  func (ks *KeyStore) Wallets() []accounts.Wallet {
   219  	// Make sure the list of wallets is in sync with the account cache
   220  	ks.refreshWallets()
   221  
   222  	ks.mu.RLock()
   223  	defer ks.mu.RUnlock()
   224  
   225  	cpy := make([]accounts.Wallet, len(ks.wallets))
   226  	copy(cpy, ks.wallets)
   227  	return cpy
   228  }
   229  
   230  // refreshWallets retrieves the current account list and based on that does any
   231  // necessary wallet refreshes.
   232  func (ks *KeyStore) refreshWallets() {
   233  	// Retrieve the current list of accounts
   234  	ks.mu.Lock()
   235  	accs := ks.cache.accounts()
   236  
   237  	// Transform the current list of wallets into the new one
   238  	var (
   239  		wallets = make([]accounts.Wallet, 0, len(accs))
   240  		events  []accounts.WalletEvent
   241  	)
   242  
   243  	for _, account := range accs {
   244  		// Drop wallets while they were in front of the next account
   245  		for len(ks.wallets) > 0 && ks.wallets[0].URL().Cmp(account.URL) < 0 {
   246  			events = append(events, accounts.WalletEvent{Wallet: ks.wallets[0], Kind: accounts.WalletDropped})
   247  			ks.wallets = ks.wallets[1:]
   248  		}
   249  		// If there are no more wallets or the account is before the next, wrap new wallet
   250  		if len(ks.wallets) == 0 || ks.wallets[0].URL().Cmp(account.URL) > 0 {
   251  			wallet := &keystoreWallet{account: account, keystore: ks}
   252  
   253  			events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletArrived})
   254  			wallets = append(wallets, wallet)
   255  			continue
   256  		}
   257  		// If the account is the same as the first wallet, keep it
   258  		if ks.wallets[0].Accounts()[0] == account {
   259  			wallets = append(wallets, ks.wallets[0])
   260  			ks.wallets = ks.wallets[1:]
   261  			continue
   262  		}
   263  	}
   264  	// Drop any leftover wallets and set the new batch
   265  	for _, wallet := range ks.wallets {
   266  		events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletDropped})
   267  	}
   268  	ks.wallets = wallets
   269  	ks.mu.Unlock()
   270  
   271  	// Fire all wallet events and return
   272  	for _, event := range events {
   273  		ks.updateFeed.Send(event)
   274  	}
   275  }
   276  
   277  // Subscribe implements accounts.Backend, creating an async subscription to
   278  // receive notifications on the addition or removal of keystore wallets.
   279  func (ks *KeyStore) Subscribe(sink chan<- accounts.WalletEvent) event.Subscription {
   280  	// We need the mutex to reliably start/stop the update loop
   281  	ks.mu.Lock()
   282  	defer ks.mu.Unlock()
   283  
   284  	// Subscribe the caller and track the subscriber count
   285  	sub := ks.updateScope.Track(ks.updateFeed.Subscribe(sink))
   286  
   287  	// Subscribers require an active notification loop, start it
   288  	if !ks.updating {
   289  		ks.updating = true
   290  		go ks.updater()
   291  	}
   292  	return sub
   293  }
   294  
   295  // updater is responsible for maintaining an up-to-date list of wallets stored in
   296  // the keystore, and for firing wallet addition/removal events. It listens for
   297  // account change events from the underlying account cache, and also periodically
   298  // forces a manual refresh (only triggers for systems where the filesystem notifier
   299  // is not running).
   300  func (ks *KeyStore) updater() {
   301  	for {
   302  		// Wait for an account update or a refresh timeout
   303  		select {
   304  		case <-ks.changes:
   305  		case <-time.After(walletRefreshCycle):
   306  		}
   307  		// Run the wallet refresher
   308  		ks.refreshWallets()
   309  
   310  		// If all our subscribers left, stop the updater
   311  		ks.mu.Lock()
   312  		if ks.updateScope.Count() == 0 {
   313  			ks.updating = false
   314  			ks.mu.Unlock()
   315  			return
   316  		}
   317  		ks.mu.Unlock()
   318  	}
   319  }
   320  
   321  // HasAddress reports whether a key with the given address is present.
   322  func (ks *KeyStore) HasAddress(addr common.Address) bool {
   323  	return ks.cache.hasAddress(addr)
   324  }
   325  
   326  // Accounts returns all key files present in the directory.
   327  func (ks *KeyStore) Accounts() []accounts.Account {
   328  	return ks.cache.accounts()
   329  }
   330  
   331  // Delete deletes the key matched by account if the passphrase is correct.
   332  // If the account contains no filename, the address must match a unique key.
   333  func (ks *KeyStore) Delete(a accounts.Account, passphrase string) error {
   334  	// Decrypting the key isn't really necessary, but we do
   335  	// it anyway to check the password and zero out the key
   336  	// immediately afterwards.
   337  	a, key, err := ks.getDecryptedKey(a, passphrase)
   338  	if key != nil {
   339  		zeroKey(key.PrivateKey)
   340  	}
   341  	if err != nil {
   342  		return err
   343  	}
   344  	// The order is crucial here. The key is dropped from the
   345  	// cache after the file is gone so that a reload happening in
   346  	// between won't insert it into the cache again.
   347  	err = os.Remove(a.URL.Path)
   348  	if err == nil {
   349  		ks.cache.delete(a)
   350  		ks.refreshWallets()
   351  	}
   352  	return err
   353  }
   354  
   355  // SignHash calculates a ECDSA signature for the given hash. The produced
   356  // signature is in the [R || S || V] format where V is 0 or 1.
   357  func (ks *KeyStore) SignHash(a accounts.Account, hash []byte) ([]byte, error) {
   358  	// Look up the key to sign with and abort if it cannot be found
   359  	ks.mu.RLock()
   360  	defer ks.mu.RUnlock()
   361  
   362  	unlockedKey, found := ks.unlocked[a.Address]
   363  	if !found {
   364  		return nil, ErrLocked
   365  	}
   366  	// Sign the hash using plain ECDSA operations
   367  	return crypto.Sign(hash, unlockedKey.PrivateKey)
   368  }
   369  
   370  // SignTx signs the given transaction with the requested account.
   371  func (ks *KeyStore) SignTx(a accounts.Account, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
   372  	// Look up the key to sign with and abort if it cannot be found
   373  	ks.mu.RLock()
   374  	defer ks.mu.RUnlock()
   375  
   376  	unlockedKey, found := ks.unlocked[a.Address]
   377  	if !found {
   378  		return nil, ErrLocked
   379  	}
   380  	// Depending on the presence of the chain ID, sign with 2718 or homestead
   381  	signer := types.LatestSignerForChainID(chainID)
   382  	return types.SignTx(tx, signer, unlockedKey.PrivateKey)
   383  }
   384  
   385  // SignHashWithPassphrase signs hash if the private key matching the given address
   386  // can be decrypted with the given passphrase. The produced signature is in the
   387  // [R || S || V] format where V is 0 or 1.
   388  func (ks *KeyStore) SignHashWithPassphrase(a accounts.Account, passphrase string, hash []byte) (signature []byte, err error) {
   389  	_, key, err := ks.getDecryptedKey(a, passphrase)
   390  	if err != nil {
   391  		return nil, err
   392  	}
   393  	defer zeroKey(key.PrivateKey)
   394  	return crypto.Sign(hash, key.PrivateKey)
   395  }
   396  
   397  // SignTxWithPassphrase signs the transaction if the private key matching the
   398  // given address can be decrypted with the given passphrase.
   399  func (ks *KeyStore) SignTxWithPassphrase(a accounts.Account, passphrase string, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
   400  	_, key, err := ks.getDecryptedKey(a, passphrase)
   401  	if err != nil {
   402  		return nil, err
   403  	}
   404  	defer zeroKey(key.PrivateKey)
   405  	// Depending on the presence of the chain ID, sign with or without replay protection.
   406  	signer := types.LatestSignerForChainID(chainID)
   407  	return types.SignTx(tx, signer, key.PrivateKey)
   408  }
   409  
   410  // Unlock unlocks the given account indefinitely.
   411  func (ks *KeyStore) Unlock(a accounts.Account, passphrase string) error {
   412  	return ks.TimedUnlock(a, passphrase, 0)
   413  }
   414  
   415  // Lock removes the private key with the given address from memory.
   416  func (ks *KeyStore) Lock(addr common.Address) error {
   417  	ks.mu.Lock()
   418  	if unl, found := ks.unlocked[addr]; found {
   419  		ks.mu.Unlock()
   420  		ks.expire(addr, unl, time.Duration(0)*time.Nanosecond)
   421  	} else {
   422  		ks.mu.Unlock()
   423  	}
   424  	return nil
   425  }
   426  
   427  // TimedUnlock unlocks the given account with the passphrase. The account
   428  // stays unlocked for the duration of timeout. A timeout of 0 unlocks the account
   429  // until the program exits. The account must match a unique key file.
   430  //
   431  // If the account address is already unlocked for a duration, TimedUnlock extends or
   432  // shortens the active unlock timeout. If the address was previously unlocked
   433  // indefinitely the timeout is not altered.
   434  func (ks *KeyStore) TimedUnlock(a accounts.Account, passphrase string, timeout time.Duration) error {
   435  	a, key, err := ks.getDecryptedKey(a, passphrase)
   436  	if err != nil {
   437  		return err
   438  	}
   439  
   440  	ks.mu.Lock()
   441  	defer ks.mu.Unlock()
   442  	u, found := ks.unlocked[a.Address]
   443  	if found {
   444  		if u.abort == nil {
   445  			// The address was unlocked indefinitely, so unlocking
   446  			// it with a timeout would be confusing.
   447  			zeroKey(key.PrivateKey)
   448  			return nil
   449  		}
   450  		// Terminate the expire goroutine and replace it below.
   451  		close(u.abort)
   452  	}
   453  	if timeout > 0 {
   454  		u = &unlocked{Key: key, abort: make(chan struct{})}
   455  		go ks.expire(a.Address, u, timeout)
   456  	} else {
   457  		u = &unlocked{Key: key}
   458  	}
   459  	ks.unlocked[a.Address] = u
   460  	return nil
   461  }
   462  
   463  // Find resolves the given account into a unique entry in the keystore.
   464  func (ks *KeyStore) Find(a accounts.Account) (accounts.Account, error) {
   465  	ks.cache.maybeReload()
   466  	ks.cache.mu.Lock()
   467  	a, err := ks.cache.find(a)
   468  	ks.cache.mu.Unlock()
   469  	return a, err
   470  }
   471  
   472  func (ks *KeyStore) getDecryptedKey(a accounts.Account, auth string) (accounts.Account, *Key, error) {
   473  	a, err := ks.Find(a)
   474  	if err != nil {
   475  		return a, nil, err
   476  	}
   477  	key, err := ks.storage.GetKey(a.Address, a.URL.Path, auth)
   478  	return a, key, err
   479  }
   480  
   481  func (ks *KeyStore) expire(addr common.Address, u *unlocked, timeout time.Duration) {
   482  	t := time.NewTimer(timeout)
   483  	defer t.Stop()
   484  	select {
   485  	case <-u.abort:
   486  		// just quit
   487  	case <-t.C:
   488  		ks.mu.Lock()
   489  		// only drop if it's still the same key instance that dropLater
   490  		// was launched with. we can check that using pointer equality
   491  		// because the map stores a new pointer every time the key is
   492  		// unlocked.
   493  		if ks.unlocked[addr] == u {
   494  			zeroKey(u.PrivateKey)
   495  			delete(ks.unlocked, addr)
   496  		}
   497  		ks.mu.Unlock()
   498  	}
   499  }
   500  
   501  // NewAccount generates a new key and stores it into the key directory,
   502  // encrypting it with the passphrase.
   503  func (ks *KeyStore) NewAccount(passphrase string) (accounts.Account, error) {
   504  	_, account, err := storeNewKey(ks.storage, crand.Reader, passphrase)
   505  	if err != nil {
   506  		return accounts.Account{}, err
   507  	}
   508  	// Add the account to the cache immediately rather
   509  	// than waiting for file system notifications to pick it up.
   510  	ks.cache.add(account)
   511  	ks.refreshWallets()
   512  	return account, nil
   513  }
   514  
   515  // Export exports as a JSON key, encrypted with newPassphrase.
   516  func (ks *KeyStore) Export(a accounts.Account, passphrase, newPassphrase string) (keyJSON []byte, err error) {
   517  	_, key, err := ks.getDecryptedKey(a, passphrase)
   518  	if err != nil {
   519  		return nil, err
   520  	}
   521  	var N, P int
   522  	if store, ok := ks.storage.(*keyStorePassphrase); ok {
   523  		N, P = store.scryptN, store.scryptP
   524  	} else {
   525  		N, P = StandardScryptN, StandardScryptP
   526  	}
   527  	return EncryptKey(key, newPassphrase, N, P)
   528  }
   529  
   530  // Import stores the given encrypted JSON key into the key directory.
   531  func (ks *KeyStore) Import(keyJSON []byte, passphrase, newPassphrase string) (accounts.Account, error) {
   532  	key, err := DecryptKey(keyJSON, passphrase)
   533  	if key != nil && key.PrivateKey != nil {
   534  		defer zeroKey(key.PrivateKey)
   535  	}
   536  	if err != nil {
   537  		return accounts.Account{}, err
   538  	}
   539  	ks.importMu.Lock()
   540  	defer ks.importMu.Unlock()
   541  
   542  	if ks.cache.hasAddress(key.Address) {
   543  		return accounts.Account{
   544  			Address: key.Address,
   545  		}, ErrAccountAlreadyExists
   546  	}
   547  	return ks.importKey(key, newPassphrase)
   548  }
   549  
   550  // ImportECDSA stores the given key into the key directory, encrypting it with the passphrase.
   551  func (ks *KeyStore) ImportECDSA(priv *ecdsa.PrivateKey, passphrase string) (accounts.Account, error) {
   552  	ks.importMu.Lock()
   553  	defer ks.importMu.Unlock()
   554  
   555  	key := newKeyFromECDSA(priv)
   556  	if ks.cache.hasAddress(key.Address) {
   557  		return accounts.Account{
   558  			Address: key.Address,
   559  		}, ErrAccountAlreadyExists
   560  	}
   561  	return ks.importKey(key, passphrase)
   562  }
   563  
   564  func (ks *KeyStore) importKey(key *Key, passphrase string) (accounts.Account, error) {
   565  	a := accounts.Account{Address: key.Address, URL: accounts.URL{Scheme: KeyStoreScheme, Path: ks.storage.JoinPath(keyFileName(key.Address))}}
   566  	if err := ks.storage.StoreKey(a.URL.Path, key, passphrase); err != nil {
   567  		return accounts.Account{}, err
   568  	}
   569  	ks.cache.add(a)
   570  	ks.refreshWallets()
   571  	return a, nil
   572  }
   573  
   574  // Update changes the passphrase of an existing account.
   575  func (ks *KeyStore) Update(a accounts.Account, passphrase, newPassphrase string) error {
   576  	a, key, err := ks.getDecryptedKey(a, passphrase)
   577  	if err != nil {
   578  		return err
   579  	}
   580  	return ks.storage.StoreKey(a.URL.Path, key, newPassphrase)
   581  }
   582  
   583  // ImportPreSaleKey decrypts the given Ethereum presale wallet and stores
   584  // a key file in the key directory. The key file is encrypted with the same passphrase.
   585  func (ks *KeyStore) ImportPreSaleKey(keyJSON []byte, passphrase string) (accounts.Account, error) {
   586  	a, _, err := importPreSaleKey(ks.storage, keyJSON, passphrase)
   587  	if err != nil {
   588  		return a, err
   589  	}
   590  	ks.cache.add(a)
   591  	ks.refreshWallets()
   592  	return a, nil
   593  }
   594  
   595  // zeroKey zeroes a private key in memory.
   596  func zeroKey(k *ecdsa.PrivateKey) {
   597  	b := k.D.Bits()
   598  	for i := range b {
   599  		b[i] = 0
   600  	}
   601  }