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 = VariableLengthEncoding.GetVariableLengthStringBytes("Bitcoin Signed Message:\n");
var messageData = VariableLengthEncoding.GetVariableLengthStringBytes(message.Message);
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 SignedMessage Sign(BigInteger privateKey, string message)
{
var magicData = VariableLengthEncoding.GetVariableLengthStringBytes("Bitcoin Signed Message:\n");
var messageData = VariableLengthEncoding.GetVariableLengthStringBytes(message);
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);//, Hex.HexToBigInteger("49ba5e10448bd527da764f0a388bbc1559cc93ea970f8564ac63a0c5e0e7e8bf"));
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);
}
