public Packet Auth(NodeId remoteNodeId, EncryptionHandshake handshake)
{
handshake.RemoteNodeId = remoteNodeId;
handshake.InitiatorNonce = _cryptoRandom.GenerateRandomBytes(32);
handshake.EphemeralPrivateKey = new PrivateKey(_cryptoRandom.GenerateRandomBytes(32));
byte[] staticSharedSecret = BouncyCrypto.Agree(_privateKey, remoteNodeId.PublicKey);
byte[] forSigning = staticSharedSecret.Xor(handshake.InitiatorNonce);
AuthEip8Message authMessage = new AuthEip8Message();
authMessage.Nonce = handshake.InitiatorNonce;
authMessage.PublicKey = _privateKey.PublicKey;
authMessage.Signature = _signer.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.PublicKey,
authData,
sizeBytes);
handshake.AuthPacket = new Packet(Bytes.Concat(sizeBytes, packetData));
return(handshake.AuthPacket);
}
public void Can_calculate_agreement()
{
PrivateKey privateKey1 = TestObject.PrivateKeyA;
PrivateKey privateKey2 = TestObject.PrivateKeyB;
byte[] sharedSecret1 = BouncyCrypto.Agree(privateKey1, privateKey2.PublicKey);
byte[] sharedSecret2 = BouncyCrypto.Agree(privateKey2, privateKey1.PublicKey);
Assert.AreEqual(sharedSecret1, sharedSecret2);
}
public void Can_calculate_agreement()
{
CryptoRandom random = new CryptoRandom();
PrivateKey privateKey1 = new PrivateKey(random.GenerateRandomBytes(32));
PrivateKey privateKey2 = new PrivateKey(random.GenerateRandomBytes(32));
byte[] sharedSecret1 = BouncyCrypto.Agree(privateKey1, privateKey2.PublicKey);
byte[] sharedSecret2 = BouncyCrypto.Agree(privateKey2, privateKey1.PublicKey);
Assert.AreEqual(sharedSecret1, sharedSecret2);
}
private void SetSecrets(EncryptionHandshake handshake, HandshakeRole handshakeRole)
{
byte[] ephemeralSharedSecret = BouncyCrypto.Agree(handshake.EphemeralPrivateKey, handshake.RemoteEphemeralPublicKey);
byte[] nonceHash = Keccak.Compute(Bytes.Concat(handshake.RecipientNonce, handshake.InitiatorNonce)).Bytes;
byte[] sharedSecret = Keccak.Compute(Bytes.Concat(ephemeralSharedSecret, nonceHash)).Bytes;
byte[] token = Keccak.Compute(sharedSecret).Bytes;
byte[] aesSecret = Keccak.Compute(Bytes.Concat(ephemeralSharedSecret, sharedSecret)).Bytes;
Array.Clear(sharedSecret, 0, sharedSecret.Length); // TODO: it was passed in the concat for Keccak so not good enough
byte[] macSecret = Keccak.Compute(Bytes.Concat(ephemeralSharedSecret, aesSecret)).Bytes;
Array.Clear(ephemeralSharedSecret, 0, ephemeralSharedSecret.Length); // TODO: it was passed in the concat for Keccak so not good enough
handshake.Secrets = new EncryptionSecrets();
handshake.Secrets.Token = token;
handshake.Secrets.AesSecret = aesSecret;
handshake.Secrets.MacSecret = macSecret;
KeccakDigest mac1 = new KeccakDigest(MacBitsSize);
mac1.BlockUpdate(macSecret.Xor(handshake.RecipientNonce), 0, macSecret.Length);
mac1.BlockUpdate(handshake.AuthPacket.Data, 0, handshake.AuthPacket.Data.Length);
KeccakDigest mac2 = new KeccakDigest(MacBitsSize);
mac2.BlockUpdate(macSecret.Xor(handshake.InitiatorNonce), 0, macSecret.Length);
mac2.BlockUpdate(handshake.AckPacket.Data, 0, handshake.AckPacket.Data.Length);
if (handshakeRole == HandshakeRole.Initiator)
{
handshake.Secrets.EgressMac = mac1;
handshake.Secrets.IngressMac = mac2;
}
else
{
handshake.Secrets.EgressMac = mac2;
handshake.Secrets.IngressMac = mac1;
}
if (_logger.IsTrace)
{
_logger.Trace($"Agreed secrets with {handshake.RemoteNodeId}");
}
#if DEBUG
if (_logger.IsTrace)
{
_logger.Trace($"{handshake.RemoteNodeId} ephemeral private key {handshake.EphemeralPrivateKey}");
_logger.Trace($"{handshake.RemoteNodeId} initiator nonce {handshake.InitiatorNonce.ToHexString()}");
_logger.Trace($"{handshake.RemoteNodeId} recipient nonce {handshake.RecipientNonce.ToHexString()}");
_logger.Trace($"{handshake.RemoteNodeId} remote ephemeral public key {handshake.RemoteEphemeralPublicKey}");
_logger.Trace($"{handshake.RemoteNodeId} remote public key {handshake.RemoteNodeId}");
_logger.Trace($"{handshake.RemoteNodeId} auth packet {handshake.AuthPacket.Data.ToHexString()}");
_logger.Trace($"{handshake.RemoteNodeId} ack packet {handshake.AckPacket.Data.ToHexString()}");
}
#endif
}
public Packet Ack(EncryptionHandshake handshake, Packet auth)
{
handshake.AuthPacket = auth;
AuthMessageBase authMessage;
bool isOld = false;
try
{
_logger.Info($"Trying to decrypt an old version of {nameof(AuthMessage)}");
byte[] plaintextOld = _eciesCipher.Decrypt(_privateKey, auth.Data);
authMessage = _messageSerializationService.Deserialize <AuthMessage>(plaintextOld);
isOld = true;
}
catch (Exception)
{
_logger.Info($"Trying to decrypt version 4 of {nameof(AuthEip8Message)}");
byte[] sizeData = auth.Data.Slice(0, 2);
byte[] plaintext = _eciesCipher.Decrypt(_privateKey, auth.Data.Slice(2), sizeData);
authMessage = _messageSerializationService.Deserialize <AuthEip8Message>(plaintext);
}
var nodeId = new NodeId(authMessage.PublicKey);
_logger.Debug($"Received AUTH v{authMessage.Version} from {nodeId}");
handshake.RemoteNodeId = nodeId;
handshake.RecipientNonce = _cryptoRandom.GenerateRandomBytes(32);
handshake.EphemeralPrivateKey = new PrivateKey(_cryptoRandom.GenerateRandomBytes(32));
handshake.InitiatorNonce = authMessage.Nonce;
byte[] staticSharedSecret = BouncyCrypto.Agree(_privateKey, handshake.RemoteNodeId.PublicKey);
byte[] forSigning = staticSharedSecret.Xor(handshake.InitiatorNonce);
handshake.RemoteEphemeralPublicKey = _signer.RecoverPublicKey(authMessage.Signature, new Keccak(forSigning));
byte[] ackData;
if (isOld) // what was the difference? shall I really include ephemeral public key in v4?
{
_logger.Debug($"Building an {nameof(AckMessage)}");
AckMessage ackMessage = new AckMessage();
ackMessage.EphemeralPublicKey = handshake.EphemeralPrivateKey.PublicKey;
ackMessage.Nonce = handshake.RecipientNonce;
ackData = _messageSerializationService.Serialize(ackMessage);
}
else
{
_logger.Debug($"Building an {nameof(AckEip8Message)}");
AckEip8Message ackMessage = new AckEip8Message();
ackMessage.EphemeralPublicKey = handshake.EphemeralPrivateKey.PublicKey;
ackMessage.Nonce = handshake.RecipientNonce;
ackData = _messageSerializationService.Serialize(ackMessage);
}
int size = ackData.Length + 32 + 16 + 65; // data + MAC + IV + pub
byte[] sizeBytes = size.ToBigEndianByteArray().Slice(2, 2);
byte[] packetData = _eciesCipher.Encrypt(handshake.RemoteNodeId.PublicKey, ackData, sizeBytes);
handshake.AckPacket = new Packet(Bytes.Concat(sizeBytes, packetData));
SetSecrets(handshake, EncryptionHandshakeRole.Recipient);
return(handshake.AckPacket);
}