// Copyright 2014 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 accounts
import (
"bytes"
"crypto/ecdsa"
"encoding/hex"
"encoding/json"
"fmt"
"io"
"io/ioutil"
"os"
"path/filepath"
"strings"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/crypto/secp256k1"
"github.com/pborman/uuid"
)
const (
version = 3
)
type Key struct {
Id uuid.UUID // Version 4 "random" for unique id not derived from key data
// to simplify lookups we also store the address
Address common.Address
// we only store privkey as pubkey/address can be derived from it
// privkey in this struct is always in plaintext
PrivateKey *ecdsa.PrivateKey
}
type keyStore interface {
// Loads and decrypts the key from disk.
GetKey(addr common.Address, filename string, auth string) (*Key, error)
// Writes and encrypts the key.
StoreKey(filename string, k *Key, auth string) error
// Joins filename with the key directory unless it is already absolute.
JoinPath(filename string) string
}
type plainKeyJSON struct {
Address string `json:"address"`
PrivateKey string `json:"privatekey"`
Id string `json:"id"`
Version int `json:"version"`
}
type encryptedKeyJSONV3 struct {
Address string `json:"address"`
Crypto cryptoJSON `json:"crypto"`
Id string `json:"id"`
Version int `json:"version"`
}
type encryptedKeyJSONV1 struct {
Address string `json:"address"`
Crypto cryptoJSON `json:"crypto"`
Id string `json:"id"`
Version string `json:"version"`
}
type cryptoJSON struct {
Cipher string `json:"cipher"`
CipherText string `json:"ciphertext"`
CipherParams cipherparamsJSON `json:"cipherparams"`
KDF string `json:"kdf"`
KDFParams map[string]interface{} `json:"kdfparams"`
MAC string `json:"mac"`
}
type cipherparamsJSON struct {
IV string `json:"iv"`
}
type scryptParamsJSON struct {
N int `json:"n"`
R int `json:"r"`
P int `json:"p"`
DkLen int `json:"dklen"`
Salt string `json:"salt"`
}
func (k *Key) MarshalJSON() (j []byte, err error) {
jStruct := plainKeyJSON{
hex.EncodeToString(k.Address[:]),
hex.EncodeToString(crypto.FromECDSA(k.PrivateKey)),
k.Id.String(),
version,
}
j, err = json.Marshal(jStruct)
return j, err
}
func (k *Key) UnmarshalJSON(j []byte) (err error) {
keyJSON := new(plainKeyJSON)
err = json.Unmarshal(j, &keyJSON)
if err != nil {
return err
}
u := new(uuid.UUID)
*u = uuid.Parse(keyJSON.Id)
k.Id = *u
addr, err := hex.DecodeString(keyJSON.Address)
if err != nil {
return err
}
privkey, err := hex.DecodeString(keyJSON.PrivateKey)
if err != nil {
return err
}
k.Address = common.BytesToAddress(addr)
k.PrivateKey = crypto.ToECDSA(privkey)
return nil
}
func newKeyFromECDSA(privateKeyECDSA *ecdsa.PrivateKey) *Key {
id := uuid.NewRandom()
key := &Key{
Id: id,
Address: crypto.PubkeyToAddress(privateKeyECDSA.PublicKey),
PrivateKey: privateKeyECDSA,
}
return key
}
// NewKeyForDirectICAP generates a key whose address fits into < 155 bits so it can fit
// into the Direct ICAP spec. for simplicity and easier compatibility with other libs, we
// retry until the first byte is 0.
func NewKeyForDirectICAP(rand io.Reader) *Key {
randBytes := make([]byte, 64)
_, err := rand.Read(randBytes)
if err != nil {
panic("key generation: could not read from random source: " + err.Error())
}
reader := bytes.NewReader(randBytes)
privateKeyECDSA, err := ecdsa.GenerateKey(secp256k1.S256(), reader)
if err != nil {
panic("key generation: ecdsa.GenerateKey failed: " + err.Error())
}
key := newKeyFromECDSA(privateKeyECDSA)
if !strings.HasPrefix(key.Address.Hex(), "0x00") {
return NewKeyForDirectICAP(rand)
}
return key
}
func newKey(rand io.Reader) (*Key, error) {
privateKeyECDSA, err := ecdsa.GenerateKey(secp256k1.S256(), rand)
if err != nil {
return nil, err
}
return newKeyFromECDSA(privateKeyECDSA), nil
}
func storeNewKey(ks keyStore, rand io.Reader, auth string) (*Key, Account, error) {
key, err := newKey(rand)
if err != nil {
return nil, Account{}, err
}
a := Account{Address: key.Address, File: ks.JoinPath(keyFileName(key.Address))}
if err := ks.StoreKey(a.File, key, auth); err != nil {
zeroKey(key.PrivateKey)
return nil, a, err
}
return key, a, err
}
func writeKeyFile(file string, content []byte) error {
// Create the keystore directory with appropriate permissions
// in case it is not present yet.
const dirPerm = 0700
if err := os.MkdirAll(filepath.Dir(file), dirPerm); err != nil {
return err
}
// Atomic write: create a temporary hidden file first
// then move it into place. TempFile assigns mode 0600.
f, err := ioutil.TempFile(filepath.Dir(file), "."+filepath.Base(file)+".tmp")
if err != nil {
return err
}
if _, err := f.Write(content); err != nil {
f.Close()
os.Remove(f.Name())
return err
}
f.Close()
return os.Rename(f.Name(), file)
}
// keyFileName implements the naming convention for keyfiles:
// UTC--<created_at UTC ISO8601>-<address hex>
func keyFileName(keyAddr common.Address) string {
ts := time.Now().UTC()
return fmt.Sprintf("UTC--%s--%s", toISO8601(ts), hex.EncodeToString(keyAddr[:]))
}
func toISO8601(t time.Time) string {
var tz string
name, offset := t.Zone()
if name == "UTC" {
tz = "Z"
} else {
tz = fmt.Sprintf("%03d00", offset/3600)
}
return fmt.Sprintf("%04d-%02d-%02dT%02d-%02d-%02d.%09d%s", t.Year(), t.Month(), t.Day(), t.Hour(), t.Minute(), t.Second(), t.Nanosecond(), tz)
}
