// mimic of VerifySignatureHashed of DefaultCrypto.cs but using different chain id
public bool VerifySignatureHashed(byte[] messageHash, byte[] signature, byte[] publicKey, bool useNewChainId)
{
if (messageHash.Length != 32 || signature.Length != SignatureSize(useNewChainId))
{
return(false);
}
return(EcVerify.Benchmark(() =>
{
var pk = new byte[64];
if (!Secp256K1.PublicKeyParse(pk, publicKey))
{
return false;
}
var publicKeySerialized = new byte[33];
if (!Secp256K1.PublicKeySerialize(publicKeySerialized, pk, Flags.SECP256K1_EC_COMPRESSED))
{
throw new Exception("Cannot serialize parsed key: how did it happen?");
}
var parsedSig = new byte[65];
var recId = (RestoreEncodedRecIdFromSignatureBuffer(signature) - 36) / 2 / ChainId(useNewChainId);
if (recId < 0 || recId > 3)
{
throw new Exception($"Invalid recId={recId}: : recId >= 0 && recId <= 3 ");
}
if (!Secp256K1.RecoverableSignatureParseCompact(parsedSig, signature.Take(64).ToArray(), recId))
{
return false;
}
return Secp256K1.Verify(parsedSig.Take(64).ToArray(), messageHash, pk);
}));
}
public void should_verify_signature()
{
var hexReader = new HexReader();
var secp256K1 = new Secp256k1();
// https://www.blockchain.com/btc/tx/9f3eca62d13c2e7bf104a8539f5768674d551ecc140f3bb9bdaf3f07d6d3f6de
// 15RpkAiu17FiYJmMiTJBvEwNQQdgEr1KvK
// 1HvRorjpF5wyY7To5QhgJDzB3C9nEPcMo1
var data = "9f3eca62d13c2e7bf104a8539f5768674d551ecc140f3bb9bdaf3f07d6d3f6de";
var signature =
"3046022100a7a1bfc118676e8dc1779a6c6dfaece6435ca20e8e2fcf4399300cc930c791e00221009a88d6a51b763fa748254fc487710998c9572bc2f01be06d1a7532c8e38a4c1901";
var pubkey = "03a5cc256133f721c66201b54f18f08053b6fc62f3dfc84c43a3a2d1c87afbe30c";
var bData = hexReader.ToByteArray(data);
var bSignature = hexReader.ToByteArray(signature);
var bPubKey = hexReader.ToByteArray(pubkey);
var output = new Span <byte>(new byte[66]);
var normalize = secp256K1.PublicKeyParse(output, bPubKey);
var res = secp256K1.Verify(bSignature.AsSpan(), bData.AsSpan(), output);
Console.WriteLine(res);
}
public static byte[] Ecdh(byte[] privateKey, byte[] publicKey)
{
try
{
Lock.AcquireWriterLock(Timeout.Infinite);
var usablePublicKey = new byte[Secp256k1.SERIALIZED_UNCOMPRESSED_PUBKEY_LENGTH];
Secp256K1.PublicKeyParse(usablePublicKey, publicKey);
var ecdhKey = new byte[Secp256k1.SERIALIZED_COMPRESSED_PUBKEY_LENGTH];
Secp256K1.Ecdh(ecdhKey, usablePublicKey, privateKey);
return(ecdhKey);
}
finally
{
Lock.ReleaseWriterLock();
}
}
public bool Verify(
HashDigest <T> messageHash,
byte[] signature,
PublicKey publicKey)
{
lock (_instanceLock)
{
var secp256K1Signature = new byte[64];
_instance.SignatureParseDer(secp256K1Signature, signature);
byte[] secp256K1PublicKey = new byte[64];
byte[] serializedPublicKey = publicKey.Format(false);
_instance.PublicKeyParse(secp256K1PublicKey, serializedPublicKey);
return(_instance.Verify(secp256K1Signature, messageHash.ToByteArray(), secp256K1PublicKey));
}
}
public static byte[] Ecdh(byte[] privateKey, byte[] publicKey)
{
try
{
Lock.AcquireWriterLock(Timeout.Infinite);
var usablePublicKey = new byte[Secp256k1.SERIALIZED_UNCOMPRESSED_PUBKEY_LENGTH];
if (!Secp256K1.PublicKeyParse(usablePublicKey, publicKey))
{
throw new PublicKeyOperationException("Parse public key failed.");
}
var ecdhKey = new byte[Secp256k1.SERIALIZED_COMPRESSED_PUBKEY_LENGTH];
if (!Secp256K1.Ecdh(ecdhKey, usablePublicKey, privateKey))
{
throw new EcdhOperationException("Compute EC Diffie- secret failed.");
}
return(ecdhKey);
}
finally
{
Lock.ReleaseWriterLock();
}
}
public static PublicKey Decode(byte[] encode)
{
return(new PublicKey(Secp256k1.PublicKeyParse(encode)));
}