public static string GetNep2FromPrivateKey(byte[] prikey, string passphrase)
{
var pubkey = Helper.GetPublicKeyFromPrivateKey(prikey);
var script_hash = Helper.GetScriptHashFromPublicKey(pubkey);
string address = Helper.GetAddressFromScriptHash(script_hash);
var b1 = Sha256(Encoding.ASCII.GetBytes(address));
var b2 = Sha256(b1);
byte[] addresshash = b2.Take(4).ToArray();
byte[] derivedkey = SCrypt.DeriveKey(Encoding.UTF8.GetBytes(passphrase), addresshash, 16384, 8, 8, 64);
byte[] derivedhalf1 = derivedkey.Take(32).ToArray();
byte[] derivedhalf2 = derivedkey.Skip(32).ToArray();
var xorinfo = XOR(prikey, derivedhalf1);
byte[] encryptedkey = AES256Encrypt(xorinfo, derivedhalf2);
byte[] buffer = new byte[39];
buffer[0] = 0x01;
buffer[1] = 0x42;
buffer[2] = 0xe0;
Buffer.BlockCopy(addresshash, 0, buffer, 3, addresshash.Length);
Buffer.BlockCopy(encryptedkey, 0, buffer, 7, encryptedkey.Length);
return(Base58CheckEncode(buffer));
}
public static byte[] GetPrivateKeyFromNEP2(string nep2, string passphrase)
{
if (nep2 == null)
{
throw new ArgumentNullException(nameof(nep2));
}
if (passphrase == null)
{
throw new ArgumentNullException(nameof(passphrase));
}
byte[] data = Base58CheckDecode(nep2);
if (data.Length != 39 || data[0] != 0x01 || data[1] != 0x42 || data[2] != 0xe0)
{
throw new FormatException();
}
byte[] addresshash = new byte[4];
Buffer.BlockCopy(data, 3, addresshash, 0, 4);
byte[] derivedkey = SCrypt.DeriveKey(Encoding.UTF8.GetBytes(passphrase), addresshash, 16384, 8, 8, 64);
byte[] derivedhalf1 = derivedkey.Take(32).ToArray();
byte[] derivedhalf2 = derivedkey.Skip(32).ToArray();
byte[] encryptedkey = new byte[32];
Buffer.BlockCopy(data, 7, encryptedkey, 0, 32);
byte[] prikey = XOR(AES256Decrypt(encryptedkey, derivedhalf2), derivedhalf1);
//Cryptography.ECC.ECPoint pubkey = Cryptography.ECC.ECCurve.Secp256r1.G * prikey;
//UInt160 script_hash = Contract.CreateSignatureRedeemScript(pubkey).ToScriptHash();
//string address = ToAddress(script_hash);
//if (!Encoding.ASCII.GetBytes(address).Sha256().Sha256().Take(4).SequenceEqual(addresshash))
// throw new FormatException();
return(prikey);
}
