Lightweight experimental cryptoprotocol, forked by LostSoulFly 🔒 🔑

This is my Bifrost fork for use with BifrostExtended which adds many features and wraps it all into a simple package to make client/server secure projects. However, you are free to use this fork without BifrostExtended as well.

I'm just an amateur who's interested in cryptography and networking. This protocol or its implementation may be heavily flawed, and I promise absolutely no expectation of security. If you're designing a security critical application, please consider using a mature and well-documented cryptoprotocol such as TLS. Thank you.

Bifrost is a cryptoprotocol, designed to be reliable, secure, lightweight and easy to understand. The whole library is around 1k lines of fully documented C#. Bifrost was designed in response to TLS, which has a very long and verbose specification document. In contrast, Bifrost is very easy to understand and doesn't require much effort to set up.

BifrostLSF mostly depends on the excellent BouncyCastle library to do crypto. Since version 0.3, Bifrost has been able to do cipher selection, click here to view a list of available cipher suites.

Since Bifrost is designed to be simple, it has its own PKI designed around PEM keypairs and raw signature files. You can use CertManager to create CAs or keypair files, or rely on the built-in CertManager.

Server side:

TcpListener listener = new TcpListener(8888);
listener.Start();
var client = listener.AcceptTcpClient();

TcpTunnel tunnel = new TcpTunnel(client);
ServerLink link = new ServerLink(tunnel);
link.LoadCertificatesFromFiles("test.ca", "server.privkey", "server.sign");

link.OnDataReceived += (l, data) =>
{
  Console.WriteLine("Received {0} bytes from client: {1}", data.Length, Encoding.UTF8.GetString(data));
  l.SendData(data);
};

var result = link.PerformHandshake();

if(result.Type != HandshakeResultType.Successful)
{
  Console.WriteLine("Handshake failed with type {0}", result.Type);
  return;
}

Console.ReadLine();

Client:

TcpClient client = new TcpClient("localhost", 8888);
TcpTunnel tunnel = new TcpTunnel(client);
ClientLink link = new ClientLink(tunnel);
link.LoadCertificatesFromFiles("test.ca", "client.privkey", "client.sign");

link.OnDataReceived += (l, data) =>
{
  Console.WriteLine("Received {0} bytes from server: {1}", data.Length, Encoding.UTF8.GetString(data));
};

var result = link.PerformHandshake();

if(result.Type != HandshakeResultType.Successful)
{
  Console.WriteLine("Handshake failed with type {0}", result.Type);
  return;
}

link.SendData(Encoding.UTF8.GetBytes("Hello World!"));

Console.ReadLine();