public void SigningTest()
{
using (var secp256k1 = new Secp256k1())
{
Span <byte> signature = new byte[Secp256k1.UNSERIALIZED_SIGNATURE_SIZE];
Span <byte> messageHash = new byte[] { 0xc9, 0xf1, 0xc7, 0x66, 0x85, 0x84, 0x5e, 0xa8, 0x1c, 0xac, 0x99, 0x25, 0xa7, 0x56, 0x58, 0x87, 0xb7, 0x77, 0x1b, 0x34, 0xb3, 0x5e, 0x64, 0x1c, 0xca, 0x85, 0xdb, 0x9f, 0xef, 0xd0, 0xe7, 0x1f };
Span <byte> secretKey = "e815acba8fcf085a0b4141060c13b8017a08da37f2eb1d6a5416adbb621560ef".HexToBytes();
bool result = secp256k1.SignRecoverable(signature, messageHash, secretKey);
Assert.True(result);
// Recover the public key
Span <byte> publicKeyOutput = new byte[Secp256k1.PUBKEY_LENGTH];
result = secp256k1.Recover(publicKeyOutput, signature, messageHash);
Assert.True(result);
// Serialize the public key
Span <byte> serializedKey = new byte[Secp256k1.SERIALIZED_PUBKEY_LENGTH];
result = secp256k1.PublicKeySerialize(serializedKey, publicKeyOutput);
Assert.True(result);
// Slice off any prefix.
serializedKey = serializedKey.Slice(serializedKey.Length - Secp256k1.PUBKEY_LENGTH);
Assert.Equal("0x3a2361270fb1bdd220a2fa0f187cc6f85079043a56fb6a968dfad7d7032b07b01213e80ecd4fb41f1500f94698b1117bc9f3335bde5efbb1330271afc6e85e92", serializedKey.ToHexString(true), true);
// Verify we could obtain the correct sender from the signature.
Span <byte> senderAddress = Keccak.ComputeHash(serializedKey).Slice(Keccak.HASH_SIZE - 20);
Assert.Equal("0x75c8aa4b12bc52c1f1860bc4e8af981d6542cccd", senderAddress.ToArray().ToHexString(true), true);
// Verify it works with variables generated from our managed code.
BigInteger ecdsa_r = BigInteger.Parse("68932463183462156574914988273446447389145511361487771160486080715355143414637");
BigInteger ecdsa_s = BigInteger.Parse("47416572686988136438359045243120473513988610648720291068939984598262749281683");
byte recoveryId = 1;
byte[] ecdsa_r_bytes = BigIntegerConverter.GetBytes(ecdsa_r);
byte[] ecdsa_s_bytes = BigIntegerConverter.GetBytes(ecdsa_s);
signature = ecdsa_r_bytes.Concat(ecdsa_s_bytes).ToArray();
// Allocate memory for the signature and create a serialized-format signature to deserialize into our native format (platform dependent, hence why we do this).
Span <byte> serializedSignature = ecdsa_r_bytes.Concat(ecdsa_s_bytes).ToArray();
signature = new byte[Secp256k1.UNSERIALIZED_SIGNATURE_SIZE];
result = secp256k1.RecoverableSignatureParseCompact(signature, serializedSignature, recoveryId);
if (!result)
{
throw new Exception("Unmanaged EC library failed to parse serialized signature.");
}
// Recover the public key
publicKeyOutput = new byte[Secp256k1.PUBKEY_LENGTH];
result = secp256k1.Recover(publicKeyOutput, signature, messageHash);
Assert.True(result);
// Serialize the public key
serializedKey = new byte[Secp256k1.SERIALIZED_PUBKEY_LENGTH];
result = secp256k1.PublicKeySerialize(serializedKey, publicKeyOutput);
Assert.True(result);
// Slice off any prefix.
serializedKey = serializedKey.Slice(serializedKey.Length - Secp256k1.PUBKEY_LENGTH);
// Assert our key
Assert.Equal("0x3a2361270fb1bdd220a2fa0f187cc6f85079043a56fb6a968dfad7d7032b07b01213e80ecd4fb41f1500f94698b1117bc9f3335bde5efbb1330271afc6e85e92", serializedKey.ToHexString(true), true);
}
}
