// Authenticate pusher
// see: https://gist.github.com/mloughran/376898
//
// The signature is a HMAC SHA256 hex digest.
// This is generated by signing a string made up of the following components concatenated with newline characters \n.
//
// * The uppercase request method (e.g. POST)
// * The request path (e.g. /some/resource)
// * The query parameters sorted by key, with keys converted to lowercase, then joined as in the query string.
// Note that the string must not be url escaped (e.g. given the keys auth_key: foo, Name: Something else, you get auth_key=foo&name=Something else)
func restAuthenticationHandler(h http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
appID := vars["app_id"]
app, err := conf.GetAppByAppID(appID)
if err != nil {
log.Error(err)
http.Error(w, "Not authorized", http.StatusUnauthorized)
return
}
params := r.URL.Query()
signature := params.Get("auth_signature")
params.Del("auth_signature")
queryString := prepareQueryString(params)
toSign := strings.ToUpper(r.Method) + "\n" + r.URL.Path + "\n" + queryString
if utils.HashMAC([]byte(toSign), []byte(app.Secret)) == signature {
h.ServeHTTP(w, r)
} else {
log.Error("Not authorized")
http.Error(w, "Not authorized", http.StatusUnauthorized)
}
})
}
func triggerHook(name string, a *app, c *channel, event hookEvent) {
if !a.WebHooks {
log.Infof("Webhooks are not enabled for app: %s", a.Name)
return
}
go func() {
log.Infof("Triggering %s event", name)
hook := webHook{TimeMs: time.Now().Unix()}
hook.Events = append(hook.Events, event)
var js []byte
var err error
js, err = json.Marshal(hook)
if err != nil {
log.Errorf("Error decoding json: %+v", err)
return
}
var req *http.Request
req, err = http.NewRequest("POST", a.URLWebHook, bytes.NewReader(js))
if err != nil {
log.Errorf("Error creating request: %+v", err)
return
}
req.Header.Set("Content-Type", "application/json")
req.Header.Set("X-Pusher-Key", a.Key)
req.Header.Set("X-Pusher-Signature", utils.HashMAC(js, []byte(a.Secret)))
log.V(1).Infof("%+v", req.Header)
log.V(1).Infof("%+v", string(js))
if _, err := http.DefaultClient.Do(req); err != nil {
log.Errorf("Error posting %s event: %+v", name, err)
}
}()
}
// Handle messages
//
// If there is an unrecoverable error then break the loop,
// otherwise just keep going.
func onMessage(conn *websocket.Conn, w http.ResponseWriter, r *http.Request, sessionID string, app *app) {
var event struct {
Event string `json:"event"`
}
for {
_, message, err := conn.ReadMessage()
if err != nil {
log.Errorf("%+v", err)
switch err {
case io.EOF:
onClose(sessionID, app)
default:
emitWSError(newGenericReconnectImmediatelyError(), conn)
}
break
}
if err := json.Unmarshal(message, &event); err != nil {
emitWSError(newGenericReconnectImmediatelyError(), conn)
break
}
log.Infof("websockets: Handling %s event", event.Event)
switch event.Event {
case "pusher:ping":
if err := conn.WriteJSON(newPongEvent()); err != nil {
emitWSError(newGenericReconnectImmediatelyError(), conn)
}
case "pusher:subscribe":
subscribeEvent := subscribeEvent{}
if err := json.Unmarshal(message, &subscribeEvent); err != nil {
emitWSError(newGenericReconnectImmediatelyError(), conn)
break
}
connection, err := app.FindConnection(sessionID)
if err != nil {
emitWSError(newGenericReconnectImmediatelyError(), conn)
break
}
channelName := strings.TrimSpace(subscribeEvent.Data.Channel)
if !utils.IsChannelNameValid(channelName) {
emitWSError(newGenericError(fmt.Sprintf("This channel name is not valid")), conn)
break
}
isPresence := strings.HasPrefix(channelName, "presence-")
isPrivate := strings.HasPrefix(channelName, "private-")
if isPresence || isPrivate {
toSign := []string{connection.SocketID, channelName}
if isPresence {
toSign = append(toSign, subscribeEvent.Data.ChannelData)
}
expectedAuthKey := fmt.Sprintf("%s:%s", app.Key, utils.HashMAC([]byte(strings.Join(toSign, ":")), []byte(app.Secret)))
if subscribeEvent.Data.Auth != expectedAuthKey {
emitWSError(newGenericError(fmt.Sprintf("Auth value for subscription to %s is invalid", channelName)), conn)
continue
}
}
channel := app.FindOrCreateChannelByChannelID(channelName)
log.Info(subscribeEvent.Data.ChannelData)
if err := app.Subscribe(channel, connection, subscribeEvent.Data.ChannelData); err != nil {
emitWSError(newGenericReconnectImmediatelyError(), conn)
}
case "pusher:unsubscribe":
unsubscribeEvent := unsubscribeEvent{}
if err := json.Unmarshal(message, &unsubscribeEvent); err != nil {
emitWSError(newGenericReconnectImmediatelyError(), conn)
}
connection, err := app.FindConnection(sessionID)
if err != nil {
emitWSError(newGenericError(fmt.Sprintf("Could not find a connection with the id %s", sessionID)), conn)
}
channel, err := app.FindChannelByChannelID(unsubscribeEvent.Data.Channel)
if err != nil {
emitWSError(newGenericError(fmt.Sprintf("Could not find a channel with the id %s", unsubscribeEvent.Data.Channel)), conn)
}
if err := app.Unsubscribe(channel, connection); err != nil {
emitWSError(newGenericReconnectImmediatelyError(), conn)
break
}
default: // CLient Events ??
// see http://pusher.com/docs/client_api_guide/client_events#trigger-events
if strings.HasPrefix(event.Event, "client-") {
if !app.UserEvents {
emitWSError(newGenericError("To send client events, you must enable this feature in the Settings."), conn)
}
clientEvent := rawEvent{}
if err := json.Unmarshal(message, &clientEvent); err != nil {
log.Error(err)
emitWSError(newGenericReconnectImmediatelyError(), conn)
break
}
channel, err := app.FindChannelByChannelID(clientEvent.Channel)
if err != nil {
emitWSError(newGenericError(fmt.Sprintf("Could not find a channel with the id %s", clientEvent.Channel)), conn)
}
if !channel.IsPresenceOrPrivate() {
emitWSError(newGenericError("Client event rejected - only supported on private and presence channels"), conn)
break
}
if err := app.Publish(channel, clientEvent, sessionID); err != nil {
log.Error(err)
emitWSError(newGenericReconnectImmediatelyError(), conn)
break
}
}
} // switch
} // For
}