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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/passphrase.go
parent13ebd8bd9468e9d769d598b0ca2afb72ba78cb97 (diff)
...
Diffstat (limited to 'accounts/keystore/passphrase.go')
-rw-r--r--accounts/keystore/passphrase.go356
1 files changed, 356 insertions, 0 deletions
diff --git a/accounts/keystore/passphrase.go b/accounts/keystore/passphrase.go
new file mode 100644
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+++ b/accounts/keystore/passphrase.go
@@ -0,0 +1,356 @@
+// 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/>.
+
+/*
+
+This key store behaves as KeyStorePlain with the difference that
+the private key is encrypted and on disk uses another JSON encoding.
+
+The crypto is documented at https://github.com/ethereum/wiki/wiki/Web3-Secret-Storage-Definition
+
+*/
+
+package keystore
+
+import (
+ "bytes"
+ "crypto/aes"
+ "crypto/rand"
+ "crypto/sha256"
+ "encoding/hex"
+ "encoding/json"
+ "fmt"
+ "io"
+ "io/ioutil"
+ "os"
+ "path/filepath"
+
+ "github.com/ava-labs/coreth/accounts"
+ "github.com/ava-labs/go-ethereum/common"
+ "github.com/ava-labs/go-ethereum/common/math"
+ "github.com/ava-labs/go-ethereum/crypto"
+ "github.com/pborman/uuid"
+ "golang.org/x/crypto/pbkdf2"
+ "golang.org/x/crypto/scrypt"
+)
+
+const (
+ keyHeaderKDF = "scrypt"
+
+ // StandardScryptN is the N parameter of Scrypt encryption algorithm, using 256MB
+ // memory and taking approximately 1s CPU time on a modern processor.
+ StandardScryptN = 1 << 18
+
+ // StandardScryptP is the P parameter of Scrypt encryption algorithm, using 256MB
+ // memory and taking approximately 1s CPU time on a modern processor.
+ StandardScryptP = 1
+
+ // LightScryptN is the N parameter of Scrypt encryption algorithm, using 4MB
+ // memory and taking approximately 100ms CPU time on a modern processor.
+ LightScryptN = 1 << 12
+
+ // LightScryptP is the P parameter of Scrypt encryption algorithm, using 4MB
+ // memory and taking approximately 100ms CPU time on a modern processor.
+ LightScryptP = 6
+
+ scryptR = 8
+ scryptDKLen = 32
+)
+
+type keyStorePassphrase struct {
+ keysDirPath string
+ scryptN int
+ scryptP int
+ // skipKeyFileVerification disables the security-feature which does
+ // reads and decrypts any newly created keyfiles. This should be 'false' in all
+ // cases except tests -- setting this to 'true' is not recommended.
+ skipKeyFileVerification bool
+}
+
+func (ks keyStorePassphrase) GetKey(addr common.Address, filename, auth string) (*Key, error) {
+ // Load the key from the keystore and decrypt its contents
+ keyjson, err := ioutil.ReadFile(filename)
+ if err != nil {
+ return nil, err
+ }
+ key, err := DecryptKey(keyjson, auth)
+ if err != nil {
+ return nil, err
+ }
+ // Make sure we're really operating on the requested key (no swap attacks)
+ if key.Address != addr {
+ return nil, fmt.Errorf("key content mismatch: have account %x, want %x", key.Address, addr)
+ }
+ return key, nil
+}
+
+// StoreKey generates a key, encrypts with 'auth' and stores in the given directory
+func StoreKey(dir, auth string, scryptN, scryptP int) (accounts.Account, error) {
+ _, a, err := storeNewKey(&keyStorePassphrase{dir, scryptN, scryptP, false}, rand.Reader, auth)
+ return a, err
+}
+
+func (ks keyStorePassphrase) StoreKey(filename string, key *Key, auth string) error {
+ keyjson, err := EncryptKey(key, auth, ks.scryptN, ks.scryptP)
+ if err != nil {
+ return err
+ }
+ // Write into temporary file
+ tmpName, err := writeTemporaryKeyFile(filename, keyjson)
+ if err != nil {
+ return err
+ }
+ if !ks.skipKeyFileVerification {
+ // Verify that we can decrypt the file with the given password.
+ _, err = ks.GetKey(key.Address, tmpName, auth)
+ if err != nil {
+ msg := "An error was encountered when saving and verifying the keystore file. \n" +
+ "This indicates that the keystore is corrupted. \n" +
+ "The corrupted file is stored at \n%v\n" +
+ "Please file a ticket at:\n\n" +
+ "https://github.com/ethereum/go-ethereum/issues." +
+ "The error was : %s"
+ return fmt.Errorf(msg, tmpName, err)
+ }
+ }
+ return os.Rename(tmpName, filename)
+}
+
+func (ks keyStorePassphrase) JoinPath(filename string) string {
+ if filepath.IsAbs(filename) {
+ return filename
+ }
+ return filepath.Join(ks.keysDirPath, filename)
+}
+
+// Encryptdata encrypts the data given as 'data' with the password 'auth'.
+func EncryptDataV3(data, auth []byte, scryptN, scryptP int) (CryptoJSON, error) {
+
+ salt := make([]byte, 32)
+ if _, err := io.ReadFull(rand.Reader, salt); err != nil {
+ panic("reading from crypto/rand failed: " + err.Error())
+ }
+ derivedKey, err := scrypt.Key(auth, salt, scryptN, scryptR, scryptP, scryptDKLen)
+ if err != nil {
+ return CryptoJSON{}, err
+ }
+ encryptKey := derivedKey[:16]
+
+ iv := make([]byte, aes.BlockSize) // 16
+ if _, err := io.ReadFull(rand.Reader, iv); err != nil {
+ panic("reading from crypto/rand failed: " + err.Error())
+ }
+ cipherText, err := aesCTRXOR(encryptKey, data, iv)
+ if err != nil {
+ return CryptoJSON{}, err
+ }
+ mac := crypto.Keccak256(derivedKey[16:32], cipherText)
+
+ scryptParamsJSON := make(map[string]interface{}, 5)
+ scryptParamsJSON["n"] = scryptN
+ scryptParamsJSON["r"] = scryptR
+ scryptParamsJSON["p"] = scryptP
+ scryptParamsJSON["dklen"] = scryptDKLen
+ scryptParamsJSON["salt"] = hex.EncodeToString(salt)
+ cipherParamsJSON := cipherparamsJSON{
+ IV: hex.EncodeToString(iv),
+ }
+
+ cryptoStruct := CryptoJSON{
+ Cipher: "aes-128-ctr",
+ CipherText: hex.EncodeToString(cipherText),
+ CipherParams: cipherParamsJSON,
+ KDF: keyHeaderKDF,
+ KDFParams: scryptParamsJSON,
+ MAC: hex.EncodeToString(mac),
+ }
+ return cryptoStruct, nil
+}
+
+// EncryptKey encrypts a key using the specified scrypt parameters into a json
+// blob that can be decrypted later on.
+func EncryptKey(key *Key, auth string, scryptN, scryptP int) ([]byte, error) {
+ keyBytes := math.PaddedBigBytes(key.PrivateKey.D, 32)
+ cryptoStruct, err := EncryptDataV3(keyBytes, []byte(auth), scryptN, scryptP)
+ if err != nil {
+ return nil, err
+ }
+ encryptedKeyJSONV3 := encryptedKeyJSONV3{
+ hex.EncodeToString(key.Address[:]),
+ cryptoStruct,
+ key.Id.String(),
+ version,
+ }
+ return json.Marshal(encryptedKeyJSONV3)
+}
+
+// DecryptKey decrypts a key from a json blob, returning the private key itself.
+func DecryptKey(keyjson []byte, auth string) (*Key, error) {
+ // Parse the json into a simple map to fetch the key version
+ m := make(map[string]interface{})
+ if err := json.Unmarshal(keyjson, &m); err != nil {
+ return nil, err
+ }
+ // Depending on the version try to parse one way or another
+ var (
+ keyBytes, keyId []byte
+ err error
+ )
+ if version, ok := m["version"].(string); ok && version == "1" {
+ k := new(encryptedKeyJSONV1)
+ if err := json.Unmarshal(keyjson, k); err != nil {
+ return nil, err
+ }
+ keyBytes, keyId, err = decryptKeyV1(k, auth)
+ } else {
+ k := new(encryptedKeyJSONV3)
+ if err := json.Unmarshal(keyjson, k); err != nil {
+ return nil, err
+ }
+ keyBytes, keyId, err = decryptKeyV3(k, auth)
+ }
+ // Handle any decryption errors and return the key
+ if err != nil {
+ return nil, err
+ }
+ key := crypto.ToECDSAUnsafe(keyBytes)
+
+ return &Key{
+ Id: uuid.UUID(keyId),
+ Address: crypto.PubkeyToAddress(key.PublicKey),
+ PrivateKey: key,
+ }, nil
+}
+
+func DecryptDataV3(cryptoJson CryptoJSON, auth string) ([]byte, error) {
+ if cryptoJson.Cipher != "aes-128-ctr" {
+ return nil, fmt.Errorf("Cipher not supported: %v", cryptoJson.Cipher)
+ }
+ mac, err := hex.DecodeString(cryptoJson.MAC)
+ if err != nil {
+ return nil, err
+ }
+
+ iv, err := hex.DecodeString(cryptoJson.CipherParams.IV)
+ if err != nil {
+ return nil, err
+ }
+
+ cipherText, err := hex.DecodeString(cryptoJson.CipherText)
+ if err != nil {
+ return nil, err
+ }
+
+ derivedKey, err := getKDFKey(cryptoJson, auth)
+ if err != nil {
+ return nil, err
+ }
+
+ calculatedMAC := crypto.Keccak256(derivedKey[16:32], cipherText)
+ if !bytes.Equal(calculatedMAC, mac) {
+ return nil, ErrDecrypt
+ }
+
+ plainText, err := aesCTRXOR(derivedKey[:16], cipherText, iv)
+ if err != nil {
+ return nil, err
+ }
+ return plainText, err
+}
+
+func decryptKeyV3(keyProtected *encryptedKeyJSONV3, auth string) (keyBytes []byte, keyId []byte, err error) {
+ if keyProtected.Version != version {
+ return nil, nil, fmt.Errorf("Version not supported: %v", keyProtected.Version)
+ }
+ keyId = uuid.Parse(keyProtected.Id)
+ plainText, err := DecryptDataV3(keyProtected.Crypto, auth)
+ if err != nil {
+ return nil, nil, err
+ }
+ return plainText, keyId, err
+}
+
+func decryptKeyV1(keyProtected *encryptedKeyJSONV1, auth string) (keyBytes []byte, keyId []byte, err error) {
+ keyId = uuid.Parse(keyProtected.Id)
+ mac, err := hex.DecodeString(keyProtected.Crypto.MAC)
+ if err != nil {
+ return nil, nil, err
+ }
+
+ iv, err := hex.DecodeString(keyProtected.Crypto.CipherParams.IV)
+ if err != nil {
+ return nil, nil, err
+ }
+
+ cipherText, err := hex.DecodeString(keyProtected.Crypto.CipherText)
+ if err != nil {
+ return nil, nil, err
+ }
+
+ derivedKey, err := getKDFKey(keyProtected.Crypto, auth)
+ if err != nil {
+ return nil, nil, err
+ }
+
+ calculatedMAC := crypto.Keccak256(derivedKey[16:32], cipherText)
+ if !bytes.Equal(calculatedMAC, mac) {
+ return nil, nil, ErrDecrypt
+ }
+
+ plainText, err := aesCBCDecrypt(crypto.Keccak256(derivedKey[:16])[:16], cipherText, iv)
+ if err != nil {
+ return nil, nil, err
+ }
+ return plainText, keyId, err
+}
+
+func getKDFKey(cryptoJSON CryptoJSON, auth string) ([]byte, error) {
+ authArray := []byte(auth)
+ salt, err := hex.DecodeString(cryptoJSON.KDFParams["salt"].(string))
+ if err != nil {
+ return nil, err
+ }
+ dkLen := ensureInt(cryptoJSON.KDFParams["dklen"])
+
+ if cryptoJSON.KDF == keyHeaderKDF {
+ n := ensureInt(cryptoJSON.KDFParams["n"])
+ r := ensureInt(cryptoJSON.KDFParams["r"])
+ p := ensureInt(cryptoJSON.KDFParams["p"])
+ return scrypt.Key(authArray, salt, n, r, p, dkLen)
+
+ } else if cryptoJSON.KDF == "pbkdf2" {
+ c := ensureInt(cryptoJSON.KDFParams["c"])
+ prf := cryptoJSON.KDFParams["prf"].(string)
+ if prf != "hmac-sha256" {
+ return nil, fmt.Errorf("Unsupported PBKDF2 PRF: %s", prf)
+ }
+ key := pbkdf2.Key(authArray, salt, c, dkLen, sha256.New)
+ return key, nil
+ }
+
+ return nil, fmt.Errorf("Unsupported KDF: %s", cryptoJSON.KDF)
+}
+
+// TODO: can we do without this when unmarshalling dynamic JSON?
+// why do integers in KDF params end up as float64 and not int after
+// unmarshal?
+func ensureInt(x interface{}) int {
+ res, ok := x.(int)
+ if !ok {
+ res = int(x.(float64))
+ }
+ return res
+}