espn-fcast

espn-fcast

var socket;
var fcastUrl;
fetch('https://fastcast.semfs.engsvc.go.com/public/websockethost')
  .then(
    function(response) {
      if (response.status !== 200) {
        console.log('Looks like there was a problem. Status Code: ' + response.status);
        return;
      }

      // Examine the text in the response
      response.json().then(function(data) {
        console.log(data);
        var wsUri = 'wss://'+data.ip+':'+data.securePort+'/FastcastService/pubsub/profiles/12000?TrafficManager-Token='+data.token;
        console.log(wsUri);
        socket = new WebSocket(wsUri);
        socket.onopen = function(event) {
          console.log('socket open: ' + event.data);
          socket.send('{"op": "C"}');
        };
        socket.onmessage = function(event) {
          console.log('socket message received from server: ' + event.data);
          var data = JSON.parse(event.data);
          console.log('op = ' + data.op);
          if (data.op == 'C') {
            var msg = {
              op: "S",
              sid: data.sid,
              tc: "event-topevents"
            };
            socket.send(JSON.stringify(msg));
          } else if (data.op == 'H') {
            fcastUrl = data.pl;
          }
        };
      });
    }
  )
  .catch(function(err) {
    console.log('Fetch Error :-S', err);
  });

I know this was a while back, but did you happen to figure out how data.pl was encrypted? I can get wss hooked up and receive data, but the key field is encrypted in some manner, and I can't figure it out. Here is a sample. The key field it pl.pl.

{"pl":"{"ts":1655143007315,"~c":1,"pl":"eJyLrlbKL1CyUipKLchJTE5V0lEqSCzJAAoUW5kZGNTlWBkZW5rWpVqZGZkYmFnUJUMZ+vkpKcX6ieWJlfq5+XmplT6ZeSC9ZYk5palKVsZmBrU6lBockpqY6w/i0MKClNSSxMycYoSJSi6ufgq6hsbGShQaXJRYjs3FRnpmrtpGlJuNK0SoYX5Gfm4qNrNBwUK5yfjiE2xDLAAeZsYr"}","op":"P","tc":"event-topevents","mid":15223020}

@harrijon you probably figured this out already, but I encountered the same problem. It's compressed and then base64 encoded. You have to decode first, then inflate. But you need to use an old version of pako (1.0.11) to inflate it, the newer versions won't work.
Something like this:

const pako = require('pako')

var pl = 'eJyLrlbKL1CyUipKLchJTE5V0lEqSCzJAAoUW5kZGNTlWBkZW5rWpVqZGZkYmFnUJUMZ+vkpKcX6ieWJlfq5+XmplT6ZeSC9ZYk5palKVsZmBrU6lBockpqY6w/i0MKClNSSxMycYoSJSi6ufgq6hsbGShQaXJRYjs3FRnpmrtpGlJuNK0SoYX5Gfm4qNrNBwUK5yfjiE2xDLAAeZsYr'
var compressed_raw = atob(pl)
var result = JSON.parse(pako.inflate(compressed_raw, { to: "string" }))