Official peer implementation.
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package connections
import (
// Engine (ProtocolEngine) encapsulates the logic necessary to make and receive Cwtch connections.
// Note: ProtocolEngine doesn't have access to any information necessary to encrypt or decrypt GroupMessages
type Engine struct {
queue *event.Queue
connectionsManager *Manager
// Engine Attributes
Identity identity.Identity
ACN connectivity.ACN
app *application.RicochetApplication
// Engine State
started bool
// Blocklist
blocked sync.Map
// Pointer to the Global Event Manager
eventManager *event.Manager
privateKey ed25519.PrivateKey
// NewProtocolEngine initializes a new engine that runs Cwtch using the given parameters
func NewProtocolEngine(privateKey ed25519.PrivateKey, acn connectivity.ACN, eventManager *event.Manager, blockedPeers []string) *Engine {
engine := new(Engine)
engine.privateKey = privateKey
engine.queue = event.NewEventQueue(100)
go engine.eventHandler()
engine.ACN = acn
engine.connectionsManager = NewConnectionsManager(engine.ACN)
go engine.connectionsManager.AttemptReconnections()
engine.eventManager = eventManager
engine.eventManager.Subscribe(event.ProtocolEngineStartListen, engine.queue.EventChannel)
engine.eventManager.Subscribe(event.PeerRequest, engine.queue.EventChannel)
engine.eventManager.Subscribe(event.InvitePeerToGroup, engine.queue.EventChannel)
engine.eventManager.Subscribe(event.JoinServer, engine.queue.EventChannel)
engine.eventManager.Subscribe(event.SendMessageToGroup, engine.queue.EventChannel)
engine.eventManager.Subscribe(event.SendMessageToPeer, engine.queue.EventChannel)
engine.eventManager.Subscribe(event.BlockPeer, engine.queue.EventChannel)
for _, peer := range blockedPeers {
engine.blocked.Store(peer, true)
return engine
// eventHandler process events from other subsystems
func (e *Engine) eventHandler() {
for {
ev := e.queue.Next()
switch ev.EventType {
case event.StatusRequest:
e.eventManager.Publish(event.Event{EventType: event.ProtocolEngineStatus, EventID: ev.EventID})
case event.PeerRequest:
case event.InvitePeerToGroup:
e.InviteOnionToGroup(ev.Data[event.RemotePeer], []byte(ev.Data[event.GroupInvite]))
case event.JoinServer:
case event.SendMessageToGroup:
e.SendMessageToGroup(ev.Data[event.GroupServer], []byte(ev.Data[event.Ciphertext]), []byte(ev.Data[event.Signature]))
case event.SendMessageToPeer:
log.Debugf("Sending Message to Peer.....")
ppc := e.connectionsManager.GetPeerPeerConnectionForOnion(ev.Data[event.RemotePeer])
if ppc != nil {
// TODO this will block.
case event.BlockPeer:
e.blocked.Store(ev.Data[event.RemotePeer], true)
case event.ProtocolEngineStartListen:
go e.listenFn()
// GetPeerHandler is an external interface function that allows callers access to a CwtchPeerHandler
// TODO: There is likely a slightly better way to encapsulate this behavior
func (e *Engine) GetPeerHandler(remotePeerHostname string) *CwtchPeerHandler {
return &CwtchPeerHandler{Onion: remotePeerHostname, EventBus: e.eventManager}
// Listen sets up an onion listener to process incoming cwtch messages
func (e *Engine) listenFn() {
ra := new(application.RicochetApplication)
onionService, err := e.ACN.Listen(e.privateKey, application.RicochetPort)
if err != nil /*&& fmt.Sprintf("%v", err) != "550 Unspecified Tor error: Onion address collision"*/ {
e.eventManager.Publish(event.NewEvent(event.ProtocolEngineStopped, map[event.Field]string{event.Identity: e.Identity.Hostname(), event.Error: err.Error()}))
af := application.ApplicationInstanceFactory{}
af.AddHandler("im.cwtch.peer", func(rai *application.ApplicationInstance) func() channels.Handler {
cpi := new(CwtchPeerInstance)
cpi.Init(rai, ra)
return func() channels.Handler {
cpc := new(peer.CwtchPeerChannel)
cpc.Handler = e.GetPeerHandler(rai.RemoteHostname)
return cpc
af.AddHandler("", func(rai *application.ApplicationInstance) func() channels.Handler {
cpi := new(CwtchPeerInstance)
cpi.Init(rai, ra)
return func() channels.Handler {
cpc := new(peer.CwtchPeerDataChannel)
cpc.Handler = e.GetPeerHandler(rai.RemoteHostname)
return cpc
ra.Init(e.ACN, e.Identity.Name, e.Identity, af, e)
log.Infof("Running cwtch peer on %v", onionService.AddressFull())
e.started = true = ra
e.eventManager.Publish(event.NewEvent(event.ProtocolEngineStopped, map[event.Field]string{event.Identity: e.Identity.Hostname()}))
// LookupContact is a V2 API Call, we want to reject all V2 Peers
// TODO Deprecate
func (e *Engine) LookupContact(hostname string, publicKey rsa.PublicKey) (allowed, known bool) {
return false, false
// ContactRequest is a V2 API Call needed to implement ContactRequestHandler Interface
// TODO Deprecate
func (e *Engine) ContactRequest(name string, message string) string {
return "Rejected"
// LookupContactV3 returns that a contact is known and allowed to communicate for all cases.
func (e *Engine) LookupContactV3(hostname string, publicKey ed25519.PublicKey) (allowed, known bool) {
// TODO: We want to autoblock those that are blocked, The known parameter has no use anymore and should be
// disregarded by peers, so we set it to false.
if _, blocked := e.blocked.Load(hostname); blocked {
return false, false
return true, false
// Shutdown tears down the eventHandler goroutine
func (e *Engine) Shutdown() {
// PeerWithOnion is the entry point for cwtchPeer relationships
func (e *Engine) PeerWithOnion(onion string) *PeerPeerConnection {
return e.connectionsManager.ManagePeerConnection(onion, e)
// InviteOnionToGroup kicks off the invite process
func (e *Engine) InviteOnionToGroup(onion string, invite []byte) error {
ppc := e.connectionsManager.GetPeerPeerConnectionForOnion(onion)
if ppc == nil {
return errors.New("peer connection not setup for onion. peers must be trusted before sending")
if ppc.GetState() == AUTHENTICATED {
log.Infof("Got connection for group: %v - Sending Invite\n", ppc)
} else {
return errors.New("cannot send invite to onion: peer connection is not ready")
return nil
// ReceiveGroupMessage is a callback function that processes GroupMessages from a given server
func (e *Engine) ReceiveGroupMessage(server string, gm *protocol.GroupMessage) {
// Publish Event so that a Profile Engine can deal with it.
// Note: This technically means that *multiple* Profile Engines could listen to the same ProtocolEngine!
e.eventManager.Publish(event.NewEvent(event.EncryptedGroupMessage, map[event.Field]string{event.Ciphertext: string(gm.GetCiphertext()), event.Signature: string(gm.GetSignature())}))
// JoinServer manages a new server connection with the given onion address
func (e *Engine) JoinServer(onion string) {
e.connectionsManager.ManageServerConnection(onion, e.ReceiveGroupMessage)
// SendMessageToGroup attemps to sent the given message to the given group id.
func (e *Engine) SendMessageToGroup(server string, ct []byte, sig []byte) error {
psc := e.connectionsManager.GetPeerServerConnectionForOnion(server)
if psc == nil {
return errors.New("could not find server connection to send message to")
gm := &protocol.GroupMessage{
Ciphertext: ct,
Signature: sig,
err := psc.SendGroupMessage(gm)
return err
// GetPeers returns a list of peer connections.
func (e *Engine) GetPeers() map[string]ConnectionState {
return e.connectionsManager.GetPeers()
// GetServers returns a list of server connections
func (e *Engine) GetServers() map[string]ConnectionState {
return e.connectionsManager.GetServers()
// CwtchPeerInstance encapsulates incoming peer connections
type CwtchPeerInstance struct {
rai *application.ApplicationInstance
ra *application.RicochetApplication
// Init sets up a CwtchPeerInstance
func (cpi *CwtchPeerInstance) Init(rai *application.ApplicationInstance, ra *application.RicochetApplication) {
cpi.rai = rai
cpi.ra = ra
// CwtchPeerHandler encapsulates handling of incoming CwtchPackets
type CwtchPeerHandler struct {
Onion string
EventBus *event.Manager
DataHandler func(string, []byte) []byte
// HandleGroupInvite handles incoming GroupInvites
func (cph *CwtchPeerHandler) HandleGroupInvite(gci *protocol.GroupChatInvite) {
log.Debugf("Received GroupID from %v %v\n", cph.Onion, gci.String())
marshal, err := proto.Marshal(gci)
if err == nil {
cph.EventBus.Publish(event.NewEvent(event.NewGroupInvite, map[event.Field]string{event.TimestampReceived: time.Now().String(), event.RemotePeer: cph.Onion, event.GroupInvite: string(marshal)}))
// HandlePacket handles the Cwtch cwtchPeer Data Channel
func (cph *CwtchPeerHandler) HandlePacket(data []byte) []byte {
cph.EventBus.Publish(event.NewEvent(event.NewMessageFromPeer, map[event.Field]string{event.TimestampReceived: time.Now().String(), event.RemotePeer: cph.Onion, event.Data: string(data)}))
return []byte{} // TODO remove this