Adding VAPID dynamic version

2 years ago · 1bf5758fb2
4 changed files with 169 additions and 96 deletions
--- a/src/notificationService.ts
+++ b/src/notificationService.ts
@ -0,0 +1,96 @@
+import { SubscriptionService, Subscription } from './subscriptionService.js';
+import { VapidService, VapidKeys } from './vapidService.js';
+import * as https from 'https';
+import * as http_ece from 'http_ece';
+import crypto from 'crypto';
+
+export interface Message {
+    title: string;
+    body?: string;
+    [key: string]: any;
+}
+
+export class NotificationService {
+
+    private subscriptionService: SubscriptionService;
+    private vapidService: VapidService;
+    private vapidKeys: VapidKeys;
+
+    constructor() {
+        this.subscriptionService = new SubscriptionService();
+        this.vapidService = new VapidService();
+    }
+
+    private generateSalt(length = 16): Buffer {
+        return crypto.randomBytes(length);
+    }
+      
+    async broadcast(message: Message): Promise<void> {
+        const subscriptions = await this.subscriptionService.fetchSubscriptions();
+        this.vapidKeys = await this.vapidService.getVapidKeys();
+
+        for (const subscription of subscriptions) {
+            await this.pushToEndpoint(subscription, message);
+        }
+    }
+
+    async sendNotification(subscription: Subscription, message: Message) {
+        this.vapidKeys = await this.vapidService.getVapidKeys();
+        await this.pushToEndpoint(subscription, message);
+    }
+
+    private async pushToEndpoint(subscription: Subscription, message: Message): Promise<void> {
+        const payload = JSON.stringify(message);
+
+        const encrypted = this.encrypt(subscription.keys.p256dh, subscription.keys.auth, payload);
+
+        const vapidHeaders = this.vapidService.createVapidAuthHeader();
+
+        const parsedUrl = new URL(subscription.endpoint);
+        const options: https.RequestOptions = {
+            method: 'POST',
+            hostname: parsedUrl.hostname,
+            path: parsedUrl.pathname,
+            port: parsedUrl.port,
+            headers: {
+                ...vapidHeaders,
+                'TTL': '60',
+                'Content-Encoding': 'aes128gcm',
+                'Content-Type': 'application/octet-stream',
+                'Content-Length': encrypted.length
+            },
+        };
+
+        return new Promise<void>((resolve, reject) => {
+            const req = https.request(options, (res) => {
+                if (res.statusCode! >= 200 && res.statusCode! < 300) {
+                    resolve();
+                } else {
+                    reject(new Error(`Failed to send push notification. Status code: ${res.statusCode}`));
+                }
+            });
+
+            req.on('error', (error) => {
+                reject(new Error(`Failed to send push notification. Error: ${error.message}`));
+            });
+
+            req.write(encrypted);
+            req.end();
+        });
+    }
+
+    private encrypt(publicKey: string, auth: string, payload: string): Buffer {
+        http_ece.keys = {
+            'p256dh': publicKey,
+            'auth': auth
+        };
+
+        return http_ece.encrypt(payload, {
+            'salt': this.generateSalt(),
+            'dh': this.vapidKeys.publicKey,
+            'keyid': 'p256dh',
+            'contentEncoding': 'aes128gcm'
+        });
+    }
+
+}
--- a/src/routes.ts
+++ b/src/routes.ts
@ -1,31 +1,21 @@
 import express from 'express';
-import { SubscriptionService } from './subscriptionService.js';
-import { WebPushService } from './webpush.js';
+import { SubscriptionService, Subscription } from './subscriptionService.js';
+import { NotificationService, Message } from './notificationService.js';

 const router = express.Router();

 router.post('/subscribe', async (req, res) => {
-  const subscription = req.body;
+  const subscription = req.body as Subscription;
  const subscriptionService = new SubscriptionService();
  await subscriptionService.addSubscription(subscription);
  res.status(201).send();
 });

-router.post('/sendNotification', async (_, res) => {
-  const webPush = new WebPushService();
-  
-  const subscriptionService = new SubscriptionService();
-  const subscriptions = await subscriptionService.fetchSubscriptions();
-
-  const data = {
-    title: "Notification Title",
-    message: "This is a message from your web push server"
-  };
-  
-  for (let sub of subscriptions) {
-    webPush.sendNotification(sub, data);
-  }
+router.post('/broadcast', async (req, res) => {
+  const message = req.body as Message;
+  const notificationService = new NotificationService();
  
+  notificationService.broadcast(message);
  res.status(201).send();
 });

--- a/src/vapidService.ts
+++ b/src/vapidService.ts
@ -0,0 +1,66 @@
+import { Database } from 'sqlite3';
+import jwt from 'jsonwebtoken';
+import crypto from 'crypto';
+
+export interface VapidKeys {
+  publicKey: string;
+  privateKey: string;
+}
+
+export class VapidService {
+  private db: Database;
+
+  constructor() {
+    this.db = new Database('vapidKeys.db');
+    this.initializeDatabase();
+  }
+
+  private initializeDatabase(): void {
+    this.db.run(`CREATE TABLE IF NOT EXISTS vapid (id INTEGER PRIMARY KEY, publicKey TEXT, privateKey TEXT)`);
+  }
+
+  private generateVAPIDKeys(): VapidKeys {
+    const ecdh = crypto.createECDH('prime256v1');
+    ecdh.generateKeys();
+    
+    return {
+      publicKey: ecdh.getPublicKey().toString('base64'),
+      privateKey: ecdh.getPrivateKey().toString('base64')
+    };
+  }
+
+  async getVapidKeys(): Promise<VapidKeys> {
+    return new Promise((resolve, reject) => {
+      this.db.get('SELECT publicKey, privateKey FROM vapid WHERE id = ?', [1], (err, row) => {
+        if (err) reject(err);
+
+        if (row) {
+          resolve({ publicKey: row.publicKey, privateKey: row.privateKey });
+        } else {
+          const keys = this.generateVAPIDKeys();
+          this.db.run('INSERT INTO vapid (publicKey, privateKey) VALUES (?, ?)', [keys.publicKey, keys.privateKey], (err) => {
+            if (err) reject(err);
+            resolve(keys);
+          });
+        }
+      });
+    });
+  }
+
+  async createVapidAuthHeader(endpoint: string, expiration: number, subject: string): Promise<{ 'Authorization': string, 'Crypto-Key': string }> {
+    const { publicKey, privateKey } = await this.getVapidKeys();
+
+    const jwtInfo = {
+      aud: new URL(endpoint).origin,
+      exp: Math.floor((Date.now() / 1000) + expiration),
+      sub: subject
+    };
+
+    const jwtToken = jwt.sign(jwtInfo, privateKey, { algorithm: 'ES256' });
+
+    return {
+      'Authorization': `vapid t=${jwtToken}, k=${publicKey}`,
+      'Crypto-Key': publicKey
+    };
+  }
+}
--- a/src/webpush.ts
+++ b/src/webpush.ts
@ -1,82 +1,3 @@
-import * as http_ece from 'http_ece';
-import { Subscription } from './subscriptionService.js';
-import * as jwt from 'jsonwebtoken';
-import * as https from 'https';
-
 export class WebPushService {

-    private vapidPrivateKey = 'YOUR_VAPID_PRIVATE_KEY';
-    private vapidPublicKey = 'YOUR_VAPID_PUBLIC_KEY';
-
-    async sendNotification(subscription: Subscription, data: any) {
-        const payload = JSON.stringify(data);
-
-        // Encrypt the payload
-        const encrypted = this.encrypt(subscription.keys.p256dh, subscription.keys.auth, payload);
-
-        // VAPID headers
-        const vapidHeaders = this.createVapidAuthHeader();
-
-        // Send the encrypted data to the endpoint
-        const parsedUrl = new URL(subscription.endpoint);
-        const options: https.RequestOptions = {
-          method: 'POST',
-          hostname: parsedUrl.hostname,
-          path: parsedUrl.pathname,
-          port: parsedUrl.port,
-          headers: {
-            ...vapidHeaders,
-            'TTL': '60', // Time-to-live in seconds
-            'Content-Encoding': 'aes128gcm',
-            'Content-Type': 'application/octet-stream',
-            'Content-Length': encrypted.length
-          },
-        };
-    
-        return new Promise<void>((resolve, reject) => {
-          const req = https.request(options, (res) => {
-            if (res.statusCode! >= 200 && res.statusCode! < 300) {
-              resolve();
-            } else {
-              reject(new Error(`Failed to send push notification. Status code: ${res.statusCode}`));
-            }
-          });
-    
-          req.on('error', (error) => {
-            reject(new Error(`Failed to send push notification. Error: ${error.message}`));
-          });
-    
-          req.write(encrypted);
-          req.end();
-        });        
-    }
-
-    encrypt(publicKey: string, auth: string, payload: string): Buffer {
-        http_ece.keys = {
-            'p256dh': publicKey,
-            'auth': auth
-        };
-
-        return http_ece.encrypt(payload, {
-            'salt': 'randomSalt',  // Ideally, you should generate a unique salt for every message.
-            'dh': 'yourVAPIDPublicKey',
-            'keyid': 'p256dh',
-            'contentEncoding': 'aes128gcm'
-        });
-    }
-
-    private createVapidAuthHeader(): { Authorization: string, 'Crypto-Key': string } {
-        const jwtPayload = {
-            aud: 'https://fcm.googleapis.com',
-            exp: Math.round(Date.now() / 1000) + (24 * 3600), // 24 hours
-            sub: 'mailto:your@email.com'
-        };
-
-        const token = jwt.sign(jwtPayload, this.vapidPrivateKey, { algorithm: 'ES256' });
-
-        return {
-            Authorization: `Bearer ${token}`,
-            'Crypto-Key': `p256ecdsa=${this.vapidPublicKey}`
-        };
-    }
 }