public byte[] GetDerivedKey(byte[] password, KDFParams parameters)
{
if (parameters is Pbkdf2)
{
var pbkdf2Params = (Pbkdf2)parameters;
return(pbkdf2Params.GetDerivedKey(password));
}
else if (parameters is KDFParams)
{
return(GenerateDerivedScryptKey(Encoding.UTF8.GetString(password)));
}
else
{
throw new Exception("unsupport kdf params");
}
}
public byte[] GetDerivedKey(byte[] password, KDFParams paras)
{
if (paras is PBKDF2Params)
{
PBKDF2Params pbkdf2Params = (PBKDF2Params)paras;
return(pbkdf2Wrapper.GetDerivedKey(password, ByteUtil.HexStringToByteArray(pbkdf2Params.Salt), pbkdf2Params.Count, pbkdf2Params.DkLen));
}
else if (paras is ScryptParams)
{
ScryptParams scryptParams = (ScryptParams)paras;
return(scryptWrapper.GetDerivedKey(password, ByteUtil.HexStringToByteArray(scryptParams.Salt), scryptParams.N, scryptParams.R, scryptParams.P, scryptParams.DkLen));
}
else
{
throw new Exception("unsupport kdf params");
}
}
public string DecryptPrivateKey(string encryptJson, string passphrase)
{
KeyStore keystore = JsonConvert.DeserializeObject <KeyStore>(encryptJson);
byte[] ciphertext = ByteUtil.HexStringToByteArray(keystore.Crypto.Ciphertext);
byte[] iv = ByteUtil.HexStringToByteArray(keystore.Crypto.Cipherparams.Iv);
KDFParams kp = keystore.Crypto.KdfParams;
string kdf = keystore.Crypto.Kdf;
byte[] derivedKey;
if (kdf == "pbkdf2")
{
PBKDF2Params pbkdf2Params = new PBKDF2Params();
pbkdf2Params.Salt = ByteUtil.ByteArrayToHexString(Encoding.UTF8.GetBytes(kp.Salt));
pbkdf2Params.DkLen = 32;
pbkdf2Params.Count = 262144;
derivedKey = GetDerivedKey(Encoding.Default.GetBytes(passphrase), pbkdf2Params);
}
else
{
KDFParams scryptParams = new KDFParams();
scryptParams.Salt = ByteUtil.ByteArrayToHexString(Encoding.UTF8.GetBytes(kp.Salt));
scryptParams.dklen = 32;
scryptParams.p = 1;
scryptParams.r = 8;
scryptParams.n = 8192;
derivedKey = GetDerivedKey(Encoding.Default.GetBytes(passphrase), scryptParams);
}
string mac = ByteUtil.ByteArrayToHexString(HashUtil.GenerateMac(derivedKey, ciphertext));
if (mac.ToUpper() != keystore.Crypto.Mac)
{
throw new Exception("Failed to decrypt.");
}
byte[] encryptKey = new byte[16];
Array.Copy(derivedKey, encryptKey, 16);
byte[] ciphertextByte = GenerateAesCtrCipher(iv, encryptKey, ciphertext);
return(ByteUtil.ByteArrayToHexString(ciphertextByte));
}
public string EncryptPrivateKey(string privateKey, string passphrase, KDFType type)
{
string address = CryptoUtil.GetAddressFromPrivateKey(privateKey);
byte[] iv = CryptoUtil.GenerateRandomBytes(16);
byte[] salt = CryptoUtil.GenerateRandomBytes(32);
byte[] derivedKey;
if (type == KDFType.PBKDF2)
{
PBKDF2Params pbkdf2Params = new PBKDF2Params();
pbkdf2Params.Salt = ByteUtil.ByteArrayToHexString(salt);
pbkdf2Params.DkLen = 32;
pbkdf2Params.Count = 262144;
derivedKey = GetDerivedKey(Encoding.Default.GetBytes(passphrase), pbkdf2Params);
}
else
{
var scryptParams = new KDFParams();
scryptParams.Salt = ByteUtil.ByteArrayToHexString(salt);
scryptParams.dklen = 32;
scryptParams.p = 1;
scryptParams.r = 8;
scryptParams.n = 8192;
derivedKey = GetDerivedKey(Encoding.Default.GetBytes(passphrase), scryptParams);
}
byte[] encryptKey = new byte[16];
Array.Copy(derivedKey, encryptKey, 16);
KeyStore cry = new KeyStore();
byte[] ciphertext = cry.GenerateAesCtrCipher(iv, encryptKey, ByteUtil.HexStringToByteArray(privateKey));
//build struct
CipherParams cipherParams = new CipherParams();
cipherParams.Iv = ByteUtil.ByteArrayToHexString(iv);
var kp = new KDFParams()
{
Salt = Encoding.UTF8.GetString(salt)
};
var crypto = new MusCipher();
crypto.Cipher = "aes-128-ctr";
crypto.Cipherparams = cipherParams;
crypto.Ciphertext = ByteUtil.ByteArrayToHexString(ciphertext);
crypto.Kdf = (type == KDFType.PBKDF2 ? "pbkdf2" : "scrypt");
crypto.KdfParams = kp;
crypto.Mac = Encoding.UTF8.GetString(HashUtil.GenerateMac(derivedKey, ciphertext));
KeyStore key = new KeyStore();
key.Address = "0x" + address;
key.Crypto = crypto;
key.Id = Guid.NewGuid().ToString();
key.Version = 3;
return(JsonConvert.SerializeObject(key));
}
