/// <summary>
/// Verifies the signature of a message using the public key
/// </summary>
/// <param name="message"></param>
/// <param name="signature"></param>
/// <param name="pubkey"></param>
/// <returns></returns>
public static bool VerifySignature(byte[] message, byte[] signature, byte[] pubkey)
{
if (pubkey.Length == 33 && (pubkey[0] == 0x02 || pubkey[0] == 0x03))
{
try
{
pubkey = ECPoint.DecodePoint(pubkey, Cryptography.ECC.ECCurve.Secp256r1).EncodePoint(false).Skip(1).ToArray();
}
catch
{
return(false);
}
}
else if (pubkey.Length == 65 && pubkey[0] == 0x04)
{
pubkey = pubkey.Skip(1).ToArray();
}
else if (pubkey.Length != 64)
{
throw new ArgumentException();
}
using (var ecdsa = ECDsa.Create(new ECParameters
{
Curve = ECCurve.NamedCurves.nistP256,
Q = new System.Security.Cryptography.ECPoint
{
X = pubkey.Take(32).ToArray(),
Y = pubkey.Skip(32).ToArray()
}
}))
{
return(ecdsa.VerifyData(message, signature, HashAlgorithmName.SHA256));
}
}
/// <summary>
/// Creates the public address of a public key
/// </summary>
/// <param name="publicKey"></param>
/// <returns></returns>
public static byte[] CreateSignatureRedeemScript(ECPoint publicKey)
{
using (var sb = new ScriptBuilder())
{
sb.EmitPush(publicKey.EncodePoint(true));
sb.Emit(OpCode.CHECKSIG);
return(sb.ToArray());
}
}
