connectanum-dart

This is a WAMP client implementation for the dart language and flutter projects. The project aims to provide a simple and extensible structure that is easy to use. With this project I want return something to the great WAMP-Protocol community.

WAMP is trademark of Crossbar.io Technologies GmbH.

Find install instructions on pub.dev.

Other Projects

• Connectanum java router, web and WebSocket server, MVC-like framework, based on WAMP-Protocol
• jsonOdm, a JavaScript mongodb like in memory data(base) handler.

TODOs

• Multithreading for callee invocations
  • callee interrupt thread on incoming cancellations
• support auto switch auth methods for methods that need to define fields in the hello. At the moment this is only wamp scram.
• get the auth id that called a method

Known Issues

If multiple authentication methods are used and wamp scram is one of it, wamp scram needs to be the first one. If not wamp scram will not modify the hello as needed and will eventually fail.

Supported WAMP features

Authentication

• ☑ WAMP-CRA
• ☑ TICKET
• ☑ CRYPTOSIGN
  • ☑ Load putty files
    • ☑ MAC validation
    • ☑ password support
  • ☑ Load open ssh files
    • ☐ file validation
    • ☑ password support
  • ☐ Load pkcs1 files
    • ☐ file validation
    • ☐ password support
  • ☐ Load pkcs8 files
    • ☐ file validation
    • ☐ password support
  • ☑ Load base64 encoded ed25519 private key
  • ☑ Load hex encoded ed25519 private key
• ☑ WAMP-SCRAM
  • ☑ Argon2
  • ☑ PBKDF2
  • ☑ reuse client key to save computation time

Advanced RPC features

• ☑ Progressive Call Results
• ☑ Progressive Calls
• ☐ Call Timeouts
• ☑ Call Canceling
• ☑ Caller Identification
• ☐ Call Trust Levels
• ☑ Shared Registration
• ☐ Sharded Registration
• ☑ Payload PassThru Mode

Advanced PUB/SUB features

• ☑ Subscriber Black- and Whitelisting
• ☑ Publisher Exclusion
• ☑ Publisher Identification
• ☐ Publication Trust Levels
• ☑ Pattern-based Subscriptions
• ☐ Sharded Subscriptions
• ☑ Subscription Revocation
• ☑ Event Retention
• ☑ Payload PassThru Mode

Transport

• ☑ WebSockets
• ☑ RawSockets
• ☑ RawSockets with large data support (connectanum router only)
• ☐ E2E encryption

Transport Encoding

• ☑ JSON
• ☑ msgpack
• ☑ CBOR
• ☐ UBJSON
• ☐ FlatBuffer

Stream model

The transport contains an incoming stream that is usually a single subscribe stream. A session will internally open a new broadcast stream as soon as the authentication process is successful. The transport stream subscription passes all incoming messages to the broadcast stream. If the transport stream is done, the broadcast stream will close as well. The broadcast stream is used to handle all session methods. The user will never touch the transport stream directly.

Start the client

To start a client you need to choose a transport module and connect it to the desired endpoint. When the connection has been established you can start to negotiate a client session by calling the client.connect() method from the client instance. On success the client will return a session object.

If your transport disconnects the session will invalidate. If reconnect is configured, the session will try to authenticate an revalidate the session again. All subscriptions and registrations will be recovered if possible.

import 'package:connectanum/connectanum.dart';
import 'package:connectanum/json.dart';

final client = Client(
  realm: "my.realm",
  transport: WebSocketTransport(
    "ws://localhost:8080/wamp",
    new Serializer(),
    WebSocketSerialization.SERIALIZATION_JSON
  )
);
final session = await client.connect().first;

RPC

to work with RPCs you need to have an established session.

import 'package:connectanum/connectanum.dart';
import 'package:connectanum/json.dart';

final client = Client(
  realm: "my.realm",
  transport: WebSocketTransport(
    "ws://localhost:8080/wamp",
    new Serializer(),
    WebSocketSerialization.SERIALIZATION_JSON
  )
);
final session = await client.connect().first;

// Register a procedure
final registered = await session.register("my.procedure");
registered.onInvoke((invocation) {
  // to something with the invocation
})

// Call a procedure
await for (final result in session.call("my.procedure")) {
  // do something with the result
}