private static byte[] GetCheckSum(byte[] data) { var hash = SHA256.DoubleHash(data); Array.Resize(ref hash, CheckSumSizeInBytes); return(hash); }
public bool Verify(SignedMessage message) { var r = new byte[32]; var s = new byte[32]; Buffer.BlockCopy(message.SignatureBytes, 1, r, 0, 32); Buffer.BlockCopy(message.SignatureBytes, 33, s, 0, 32); var recId = message.SignatureBytes[0] - 27; var magicData = ("Bitcoin Signed Message:\n").GetVarString(); var messageData = message.Message.GetVarString(); var data = new byte[magicData.Length + messageData.Length]; Buffer.BlockCopy(magicData, 0, data, 0, magicData.Length); Buffer.BlockCopy(messageData, 0, data, magicData.Length, messageData.Length); var hash = SHA256.DoubleHash(data); var point = signer.RecoverFromSignature(hash, r.ToBigIntegerUnsigned(true), s.ToBigIntegerUnsigned(true), recId); var pubKeyHash = Hash160.Hash(point.EncodePoint(false)); var addressBytes = new byte[pubKeyHash.Length + 1]; Buffer.BlockCopy(pubKeyHash, 0, addressBytes, 1, pubKeyHash.Length); var address = Base58.EncodeWithCheckSum(addressBytes); if (address == message.Address) { return(true); } return(false); }
public byte[] DecipherKey(BigInteger privateKey, ECPoint tag) { var keyPoint = tag.Multiply(privateKey); var key = SHA256.DoubleHash(keyPoint.EncodePoint(false)); return(key); }
public ECPoint GenerateKey(ECPoint publicKey, out byte[] key, BigInteger?k) { for (int i = 0; i < 100; i++) { if (k == null) { byte[] kBytes = new byte[33]; rngCsp.GetBytes(kBytes); kBytes[32] = 0; k = new BigInteger(kBytes); } if (k.Value.IsZero || k.Value >= Secp256k1.N) { continue; } var tag = Secp256k1.G.Multiply(k.Value); var keyPoint = publicKey.Multiply(k.Value); if (keyPoint.IsInfinity || tag.IsInfinity) { continue; } key = SHA256.DoubleHash(keyPoint.EncodePoint(false)); return(tag); } throw new Exception("Unable to generate key"); }
public SignedMessage Sign(BigInteger privateKey, string message) { var magicData = ("Bitcoin Signed Message:\n").GetVarString(); var messageData = message.GetVarString(); var data = new byte[magicData.Length + messageData.Length]; Buffer.BlockCopy(magicData, 0, data, 0, magicData.Length); Buffer.BlockCopy(messageData, 0, data, magicData.Length, messageData.Length); var hash = SHA256.DoubleHash(data); var signature = signer.GenerateSignature(privateKey, hash); var recId = -1; var publicKey = Secp256k1.G.Multiply(privateKey); for (var i = 0; i < 4; i++) { var Q = signer.RecoverFromSignature(hash, signature[0], signature[1], i); if (Q.X == publicKey.X && Q.Y == publicKey.Y) { recId = i; break; } } if (recId == -1) { throw new Exception("Did not find proper recid"); } var signatureBytes = new byte[65]; signatureBytes[0] = (byte)(27 + recId); var rByteArray = signature[0].ToByteArrayUnsigned(true); var sByteArray = signature[1].ToByteArrayUnsigned(true); Buffer.BlockCopy(rByteArray, 0, signatureBytes, 1 + (32 - rByteArray.Length), rByteArray.Length); Buffer.BlockCopy(sByteArray, 0, signatureBytes, 33 + (32 - sByteArray.Length), sByteArray.Length); var signedMessage = new SignedMessage(message, publicKey.GetBitcoinAddress(), signatureBytes); return(signedMessage); }