BlueHeighliner.Msmt 0.3.0

Msmt

A C# implementation of the Mercury Secure Message Transport (MSMT) standard - an open, standards-based interface for secure message transport over IP networks, defined by MITRE's Mercury Secure Message Transport Interface Control Document (ICD). MSMT is a fixed, narrowly pinned configuration of TLS 1.3 paired with a thin, standardized message-framing API; this library implements that interface end to end on top of BouncyCastle's TLS engine.

Installing

dotnet add package BlueHeighliner.Msmt

Getting started

A peer sends messages directly to targets and receives them directly from targets, in message mode or message-with-rekeying mode:

using BlueHeighliner.Msmt;

MsmtCredentials credentials = MsmtCredentials.FromPemFiles("identity.pem", "identity.key", "ca.pem");

// RequireFullyQualifiedHostname is disabled here only because this example connects by loopback IP
// address rather than a real DNS hostname; leave it enabled (the default) whenever a hostname is used.
IMsmtMessagePeer peer = new IMsmtMessagePeer.Factory().Create(new MsmtMessagePeerOptions { Credentials = credentials, RequireFullyQualifiedHostname = false });

// The handler owns payload and must dispose it; responder is null because this message never requested an acknowledgement.
peer.Receiver = (source, identity, payload, responder) =>
{
    using (payload)
    {
        Console.WriteLine(Encoding.UTF8.GetString(payload.Memory.Span));
    }
};

peer.StartListener(port: 5000);
peer.Send(new MsmtTarget { Host = "127.0.0.1", Port = 5000 }, "hello"u8.ToArray());

A session peer listens for and opens session connections, which are bidirectional: both sides send and receive over the same connection object.

IMsmtSessionPeer listening = new IMsmtSessionPeer.Factory().Create(new MsmtSessionPeerOptions { Credentials = credentials, RequireFullyQualifiedHostname = false });
listening.Receiver = (connection, payload, responder) =>
{
    Console.WriteLine($"got {payload.Memory.Length} bytes");
    payload.Dispose();
    responder?.Accept(); // non-null only for a message sent with Request, which must be answered, once
};
listening.Connected.Subscribe(connection => connection.Send("welcome"u8.ToArray())); // the listening side can send too
listening.StartListener(port: 5000);

IMsmtSessionPeer connecting = new IMsmtSessionPeer.Factory().Create(new MsmtSessionPeerOptions { Credentials = credentials });
connecting.Receiver = (connection, payload, responder) =>
{
    Console.WriteLine("connecting side got a message");
    payload.Dispose();
    responder?.Accept();
};
IMsmtConnection connection = connecting.Connect(new MsmtNameTarget { Host = "127.0.0.1", Port = 5000, ServerName = "127.0.0.1" });
await connection.Wait(); // still Connecting until this resolves
MsmtResponse response = await connection.Request("hello"u8.ToArray());

Documentation