From c856d17730021ccea67c8e04c075c377a398e591 Mon Sep 17 00:00:00 2001
From: javajuice1337 <54199175+javajuice1337@users.noreply.github.com>
Date: Fri, 29 Mar 2024 14:24:32 -0400
Subject: [PATCH] Update index.js

---
 src/fcm/index.js | 69 ++++++++++++++++++++++++++++++++++++------------
 1 file changed, 52 insertions(+), 17 deletions(-)

diff --git a/src/fcm/index.js b/src/fcm/index.js
index 408c097..776de1f 100644
--- a/src/fcm/index.js
+++ b/src/fcm/index.js
@@ -2,35 +2,70 @@ const crypto = require('crypto');
 const request = require('request-promise');
 const { escape } = require('../utils/base64');
 
-const FCM_SUBSCRIBE = 'https://fcm.googleapis.com/fcm/connect/subscribe';
+const FIREBASE_INSTALLATION = 'https://firebaseinstallations.googleapis.com/v1/';
+const FCM_REGISTRATION = 'https://fcmregistrations.googleapis.com/v1/';
 const FCM_ENDPOINT = 'https://fcm.googleapis.com/fcm/send';
 
-module.exports = registerFCM;
+module.exports = { installFCM, registerFCM };
 
-async function registerFCM({ senderId, token }) {
+function generateFirebaseFID() {
+  // A valid FID has exactly 22 base64 characters, which is 132 bits, or 16.5
+  // bytes. our implementation generates a 17 byte array instead.
+  let fid = crypto.randomBytes(17);
+
+  // Replace the first 4 random bits with the constant FID header of 0b0111.
+  fid[0] = 0b01110000 + (fid[0] % 0b00010000);
+
+  return fid.toString('base64');
+}
+
+async function installFCM(config) {
+  const response = await request({
+    url     : `${FIREBASE_INSTALLATION}projects/${config.firebase.projectID}/installations`,
+    method  : 'POST',
+    headers : {
+      'x-firebase-client': btoa(JSON.stringify({ heartbeats: [], version: 2 })).toString('base64'),
+      'x-goog-api-key': config.firebase.apiKey
+    },
+    body : {
+      appId: config.firebase.appID,
+      authVersion: 'FIS_v2',
+      fid: generateFirebaseFID(),
+      sdkVersion: 'w:0.6.4'
+    },
+    json: true
+  });
+  return response;
+}
+
+async function registerFCM(config) {
   const keys = await createKeys();
   const response = await request({
-    url     : FCM_SUBSCRIBE,
+    url     : `${FCM_REGISTRATION}projects/${config.firebase.projectID}/registrations`,
     method  : 'POST',
     headers : {
-      'Content-Type' : 'application/x-www-form-urlencoded',
+      'x-goog-api-key' : config.firebase.apiKey,
+      'x-goog-firebase-installations-auth' : config.authToken
     },
-    form : {
-      authorized_entity : senderId,
-      endpoint          : `${FCM_ENDPOINT}/${token}`,
-      encryption_key    : keys.publicKey
-        .replace(/=/g, '')
-        .replace(/\+/g, '-')
-        .replace(/\//g, '_'),
-      encryption_auth : keys.authSecret
-        .replace(/=/g, '')
-        .replace(/\+/g, '-')
-        .replace(/\//g, '_'),
+    body : {
+      web: {
+        applicationPubKey: config.vapidKey,
+        auth: keys.authSecret
+          .replace(/=/g, '')
+          .replace(/\+/g, '-')
+          .replace(/\//g, '_'),
+        endpoint: `${FCM_ENDPOINT}/${config.token}`,
+        p256dh: keys.publicKey
+          .replace(/=/g, '')
+          .replace(/\+/g, '-')
+          .replace(/\//g, '_')
+      }
     },
+    json: true
   });
   return {
     keys,
-    fcm : JSON.parse(response),
+    fcm : response,
   };
 }