Authentication

Client side

var credentials = new ClientCredentials()
{
    UserName = "user",
    Password = "password",
    // Token = "..."
};
var client = new Client("127.0.0.1", 8200, credentials);

A ClientCredentials object allows passing basic authentication info, but derived class instance is also supported.

Server side

var server = new Server("127.0.0.1", 8200);
server.ClientAuthenticate += (s, e) =>
{
    if (MyValidateMethod(e.Credentials))
    {
        e.Identity = e.Credentials.UserName;
        e.Authenticated = true;
    }
};

bool MyValidateMethod(ClientCredentials credentials) { ... }

To enable authentication, subscribe to ClientAuthenticate event. To authenticate the user, the Authenticated property must be set to true, otherwise ClientAuthenticationException exception will be thrown on the client’s side.

Identity fallback

If the handler sets Authenticated = true but does not explicitly set Identity, the server falls back to Credentials.UserName. If the client connects without passing a ClientCredentials instance at all, the server reports it through ClientConnectingError and closes the connection. Either always set Identity explicitly, or make sure clients always pass a ClientCredentials object when authentication is enabled.

SSL/TLS

Authentication runs over whatever transport the connection was opened with. To also encrypt the connection itself, pass a certificate to the server and connect the client with ConnectSslAsync:

// Server: pass a certificate to enable SSL
var server = new Server("127.0.0.1", 8200, myX509Certificate);

// Client: connect over SSL
var client = new Client("127.0.0.1", 8200);
await client.ConnectSslAsync();          // or ConnectSslAsync("server-name") for cert name validation

Internally this wraps the socket in an SslStream and negotiates TLS 1.2 (and TLS 1.3 on .NET 7+).