// 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 keystore import ( "crypto/aes" "crypto/cipher" "crypto/sha256" "encoding/hex" "encoding/json" "errors" "fmt" "github.com/ava-labs/coreth/accounts" "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) (accounts.Account, *Key, error) { key, err := decryptPreSaleKey(keyJSON, password) if err != nil { return accounts.Account{}, nil, err } key.Id = uuid.NewRandom() a := accounts.Account{ Address: key.Address, URL: accounts.URL{ Scheme: KeyStoreScheme, Path: keyStore.JoinPath(keyFileName(key.Address)), }, } err = keyStore.StoreKey(a.URL.Path, key, password) return a, 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) if err != nil { return nil, errors.New("invalid hex in encSeed") } if len(encSeedBytes) < 16 { return nil, errors.New("invalid encSeed, too short") } 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.ToECDSAUnsafe(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 { return nil, ErrDecrypt } 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)] }