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-rw-r--r--accounts/presale.go132
1 files changed, 132 insertions, 0 deletions
diff --git a/accounts/presale.go b/accounts/presale.go
new file mode 100644
index 000000000..8faa98558
--- /dev/null
+++ b/accounts/presale.go
@@ -0,0 +1,132 @@
+// Copyright 2016 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 (
+ "crypto/aes"
+ "crypto/cipher"
+ "crypto/sha256"
+ "encoding/hex"
+ "encoding/json"
+ "errors"
+ "fmt"
+
+ "github.com/ethereum/go-ethereum/crypto"
+ "github.com/pborman/uuid"
+ "golang.org/x/crypto/pbkdf2"
+)
+
+// creates a Key and stores that in the given KeyStore by decrypting a presale key JSON
+func importPreSaleKey(keyStore keyStore, keyJSON []byte, password string) (*Key, error) {
+ key, err := decryptPreSaleKey(keyJSON, password)
+ if err != nil {
+ return nil, err
+ }
+ key.Id = uuid.NewRandom()
+ err = keyStore.StoreKey(key, password)
+ return key, err
+}
+
+func decryptPreSaleKey(fileContent []byte, password string) (key *Key, err error) {
+ preSaleKeyStruct := struct {
+ EncSeed string
+ EthAddr string
+ Email string
+ BtcAddr string
+ }{}
+ err = json.Unmarshal(fileContent, &preSaleKeyStruct)
+ if err != nil {
+ return nil, err
+ }
+ encSeedBytes, err := hex.DecodeString(preSaleKeyStruct.EncSeed)
+ iv := encSeedBytes[:16]
+ cipherText := encSeedBytes[16:]
+ /*
+ See https://github.com/ethereum/pyethsaletool
+
+ pyethsaletool generates the encryption key from password by
+ 2000 rounds of PBKDF2 with HMAC-SHA-256 using password as salt (:().
+ 16 byte key length within PBKDF2 and resulting key is used as AES key
+ */
+ passBytes := []byte(password)
+ derivedKey := pbkdf2.Key(passBytes, passBytes, 2000, 16, sha256.New)
+ plainText, err := aesCBCDecrypt(derivedKey, cipherText, iv)
+ if err != nil {
+ return nil, err
+ }
+ ethPriv := crypto.Keccak256(plainText)
+ ecKey := crypto.ToECDSA(ethPriv)
+ key = &Key{
+ Id: nil,
+ Address: crypto.PubkeyToAddress(ecKey.PublicKey),
+ PrivateKey: ecKey,
+ }
+ derivedAddr := hex.EncodeToString(key.Address.Bytes()) // needed because .Hex() gives leading "0x"
+ expectedAddr := preSaleKeyStruct.EthAddr
+ if derivedAddr != expectedAddr {
+ err = fmt.Errorf("decrypted addr '%s' not equal to expected addr '%s'", derivedAddr, expectedAddr)
+ }
+ return key, err
+}
+
+func aesCTRXOR(key, inText, iv []byte) ([]byte, error) {
+ // AES-128 is selected due to size of encryptKey.
+ aesBlock, err := aes.NewCipher(key)
+ if err != nil {
+ return nil, err
+ }
+ stream := cipher.NewCTR(aesBlock, iv)
+ outText := make([]byte, len(inText))
+ stream.XORKeyStream(outText, inText)
+ return outText, err
+}
+
+func aesCBCDecrypt(key, cipherText, iv []byte) ([]byte, error) {
+ aesBlock, err := aes.NewCipher(key)
+ if err != nil {
+ return nil, err
+ }
+ decrypter := cipher.NewCBCDecrypter(aesBlock, iv)
+ paddedPlaintext := make([]byte, len(cipherText))
+ decrypter.CryptBlocks(paddedPlaintext, cipherText)
+ plaintext := pkcs7Unpad(paddedPlaintext)
+ if plaintext == nil {
+ err = errors.New("Decryption failed: PKCS7Unpad failed after AES decryption")
+ }
+ return plaintext, err
+}
+
+// From https://leanpub.com/gocrypto/read#leanpub-auto-block-cipher-modes
+func pkcs7Unpad(in []byte) []byte {
+ if len(in) == 0 {
+ return nil
+ }
+
+ padding := in[len(in)-1]
+ if int(padding) > len(in) || padding > aes.BlockSize {
+ return nil
+ } else if padding == 0 {
+ return nil
+ }
+
+ for i := len(in) - 1; i > len(in)-int(padding)-1; i-- {
+ if in[i] != padding {
+ return nil
+ }
+ }
+ return in[:len(in)-int(padding)]
+}