public static bool TryParse(ReadOnlySpan <byte> in64, out SchnorrSignature sig)
{
sig = null;
if (in64.Length != 64)
{
return(false);
}
if (!Secp256k1.SecpSchnorrSignature.TryCreate(in64, out var secpShnorr) || secpShnorr is null)
{
return(false);
}
sig = new SchnorrSignature(secpShnorr);
return(true);
}
public static bool TryParse(byte[] in64, [MaybeNullWhen(false)] out SchnorrSignature sig)
{
if (in64 == null)
{
throw new ArgumentNullException(nameof(in64));
}
sig = null;
if (in64.Length != 64)
{
return(false);
}
sig = new SchnorrSignature(in64);
return(true);
}
public bool Verify(uint256 m, PubKey pubkey, SchnorrSignature sig)
{
if (sig.R.CompareTo(PP) >= 0 || sig.S.CompareTo(Secp256k1.N) >= 0)
{
return(false);
}
var e = new BigInteger(1, Hashes.SHA256(Utils.BigIntegerToBytes(sig.R, 32).Concat(pubkey.ToBytes(), m.ToBytes()))).Mod(Secp256k1.N);
var q = pubkey.ECKey.GetPublicKeyParameters().Q.Normalize();
var P = Secp256k1.Curve.CreatePoint(q.XCoord.ToBigInteger(), q.YCoord.ToBigInteger());
var R = Secp256k1.G.Multiply(sig.S).Add(P.Multiply(Secp256k1.N.Subtract(e))).Normalize();
if (R.IsInfinity ||
R.XCoord.ToBigInteger().CompareTo(sig.R) != 0 ||
BigInteger.Jacobi(R.YCoord.ToBigInteger(), PP) != 1)
{
return(false);
}
return(true);
}
public static bool TryParse(byte[] in64, [MaybeNullWhen(false)] out SchnorrSignature sig)
{
return(TryParse(in64.AsSpan(), out sig));
}