private void HandleEncryption(EncryptionRequestPacket packet)
{
var random = RandomNumberGenerator.Create();
_sharedSecret = new byte[16];
random.GetBytes(_sharedSecret);
if (packet.ServerId != "")
{
throw new NotImplementedException("Online mode is not implemented");
}
var parser = new AsnKeyParser(packet.PublicKey);
var key = parser.ParseRSAPublicKey();
// Encrypt shared secret and verification token
var crypto = new RSACryptoServiceProvider();
crypto.ImportParameters(key);
WritePacket(new EncryptionResponsePacket
{
SharedSecret = crypto.Encrypt(_sharedSecret, false),
VerifyToken = crypto.Encrypt(packet.VerifyToken, false),
});
_baseStream = new AesStream(_networkStream, _sharedSecret);
_writer = new MinecraftStreamWriter(_baseStream);
_reader = new MinecraftStreamReader(_baseStream);
}
/// <summary>
/// Compose and send an encryption request packet to the server
/// </summary>
private void SendEncryptionRequest()
{
// Create the encryption request packet
EncryptionRequestPacket packet = new EncryptionRequestPacket();
// Add the game packet handlers
AddGamePacketHandler(0x00, new SessionPacketHandler(SpecialPacketReceiveHandler));
// Add the special packet handlers
AddSpecialPacketHandler(0x02, new SessionPacketHandler(HandleEncryptionResponse));
AddSpecialPacketHandler(0x05, new SessionPacketHandler(HandleSynchronizeRequest));
AddSpecialPacketHandler(0x07, new SessionPacketHandler(HandleDisconnect));
// Log the connection message
m_sessionLogger(String.Format("Connecting to {0}:{1}",
m_sessionSettings.ServerAddress,
m_sessionSettings.ServerPort));
// Set the client encryption key value
packet.EncryptionKey = m_sessionSocket.ClientEncryptKey;
// Send the packet to the server
TransmitPacket(packet);
}
private void HandleEncryptionRequest(EncryptionRequestPacket packet)
{
var generator = new CipherKeyGenerator();
generator.Init(new KeyGenerationParameters(new SecureRandom(), 16 * 8));
var sharedKey = generator.GenerateKey();
var pkcs = new PKCS1Signer(packet.PublicKey);
var signedSecret = pkcs.SignData(sharedKey);
var signedVerify = pkcs.SignData(packet.VerificationToken);
SendPacketDirect(new EncryptionResponsePacket { SharedSecret = signedSecret, VerificationToken = signedVerify });
Stream.InitializeEncryption(sharedKey);
State |= JoinState.JoinedGame;
}
/// <summary>
/// Gets the next packet from the server
/// </summary>
/// <returns></returns>
public PacketData ReadNextPacket()
{
int packetId;
byte[] payload;
lock (_streamReadLock)
{
int length = VarInt.ReadNext(ReadBytes);
List <byte> buffer = new List <byte>();
// check if data is compressed
if (_compressionThreshold >= 0)
{
int dataLength = VarInt.ReadNext(ReadBytes);
length -= VarInt.GetBytes(dataLength).Length; // remove size of data length from rest of packet length
if (dataLength != 0)
{
byte[] compressedBuffer = ReadBytes(length);
buffer.AddRange(ZlibStream.UncompressBuffer(compressedBuffer));
}
else
{
buffer.AddRange(ReadBytes(length));
}
}
else
{
buffer.AddRange(ReadBytes(length));
}
packetId = VarInt.ReadNext(buffer);
payload = buffer.ToArray();
}
// handles some stuff during login phase
if (State == ProtocolState.LOGIN)
{
// handle compression packet
if (packetId == (int)ClientboundIDs.LogIn_SetCompression)
{
_compressionThreshold = VarInt.ReadNext(new List <byte>(payload));
return(ReadNextPacket());
}
// handle protocol encryption packet
if (packetId == (int)ClientboundIDs.LogIn_EncryptionRequest)
{
var encRequestPkt = new EncryptionRequestPacket()
{
Payload = payload
};
var aesSecret = CryptoHandler.GenerateSharedSecret();
var authHash = CryptoHandler.SHAHash(Encoding.ASCII.GetBytes(encRequestPkt.ServerID).Concat(aesSecret, encRequestPkt.PublicKey));
Debug.Log($"Sending hash to Mojang servers: {authHash}");
// check session with mojang
if (!MojangAPI.JoinServer(authHash))
{
throw new UnityException("Invalid session. (Try restarting game or relogging into Minecraft account)");
}
// use pub key to encrypt shared secret
using (var rsaProvider = CryptoHandler.DecodeRSAPublicKey(encRequestPkt.PublicKey))
{
byte[] encSecret = rsaProvider.Encrypt(aesSecret, false);
byte[] encToken = rsaProvider.Encrypt(encRequestPkt.VerifyToken, false);
// respond to server with private key
var responsePkt = new EncryptionResponsePacket()
{
SharedSecret = encSecret,
VerifyToken = encToken
};
WritePacket(responsePkt);
// enable aes encryption
_aesStream = new AesStream(Client.GetStream(), aesSecret);
_encrypted = true;
// read the next packet
return(ReadNextPacket());
}
}
}
return(new PacketData
{
ID = packetId,
Payload = payload
});
}
