public Packet Auth(PublicKey remoteNodeId, EncryptionHandshake handshake)
{
handshake.RemoteNodeId = remoteNodeId;
handshake.InitiatorNonce = _cryptoRandom.GenerateRandomBytes(32);
handshake.EphemeralPrivateKey = _ephemeralGenerator.Generate();
byte[] staticSharedSecret = Proxy.EcdhSerialized(remoteNodeId.Bytes, _privateKey.KeyBytes);
byte[] forSigning = staticSharedSecret.Xor(handshake.InitiatorNonce);
AuthEip8Message authMessage = new AuthEip8Message();
authMessage.Nonce = handshake.InitiatorNonce;
authMessage.PublicKey = _privateKey.PublicKey;
authMessage.Signature = _ecdsa.Sign(handshake.EphemeralPrivateKey, new Keccak(forSigning));
byte[] authData = _messageSerializationService.Serialize(authMessage);
int size = authData.Length + 32 + 16 + 65; // data + MAC + IV + pub
byte[] sizeBytes = size.ToBigEndianByteArray().Slice(2, 2);
byte[] packetData = _eciesCipher.Encrypt(
remoteNodeId,
authData,
sizeBytes);
handshake.AuthPacket = new Packet(Bytes.Concat(sizeBytes, packetData));
return(handshake.AuthPacket);
}
protected byte[] Serialize(byte[] type, byte[] data)
{
byte[] payload = Bytes.Concat(type[0], data);
Keccak toSign = Keccak.Compute(payload);
Signature signature = _ecdsa.Sign(_privateKey, toSign);
byte[] signatureBytes = Bytes.Concat(signature.Bytes, signature.RecoveryId);
byte[] mdc = Keccak.Compute(Bytes.Concat(signatureBytes, type, data)).Bytes;
return(Bytes.Concat(mdc, signatureBytes, type, data));
}
protected byte[] Serialize(byte type, Span <byte> data)
{
Span <byte> result = new byte[32 + 1 + data.Length + 64 + 1].AsSpan();
result[32 + 65] = type;
data.CopyTo(result.Slice(32 + 65 + 1, data.Length));
Span <byte> payload = result.Slice(32 + 65);
Keccak toSign = Keccak.Compute(payload);
Signature signature = _ecdsa.Sign(_privateKey, toSign);
signature.Bytes.AsSpan().CopyTo(result.Slice(32, 64));
result[32 + 64] = signature.RecoveryId;
Span <byte> forMdc = result.Slice(32);
Keccak mdc = Keccak.Compute(forMdc);
mdc.Bytes.AsSpan().CopyTo(result.Slice(0, 32));
return(result.ToArray());
}
/// <summary>
/// Signs the node record with own private key.
/// </summary>
/// <param name="nodeRecord"></param>
public void Sign(NodeRecord nodeRecord)
{
nodeRecord.Signature = _ecdsa.Sign(_privateKey, nodeRecord.ContentHash);
}