For those of you building on top of firebase, here is a quick Typescript implementation of the JWT generateSignature() method (see: https://marketplace.zoom.us/docs/sdk/native-sdks/web/essential/signature) as a firebase cloud function.
Note: I tried to do an implementation without loading express but for some reason I could not the cors to work properly.
/**
* A quick TypeScript implementation of the Zoom JWT generate signature() method with `firebase cloud functions`. see:
* - https://marketplace.zoom.us/docs/sdk/native-sdks/web/essential/signature
* - https://firebase.google.com/docs/functions
* - https://firebase.google.com/docs/functions/typescript
*
* Configuration Notes
*
* for Zoom JWT Credentials:
* for apiKey/apiSecret, see: https://marketplace.zoom.us/develop/create
* install firebase cloud functions dependencies:
```
// from firebase tools CLI
cd ./functions
npm install --save express cors
```
* save Zoom JWT apiKey/Secret to firebase functions as environment vars
```
// from firebase tools CLI
firebase functions:config:set zoom.apikey="[apiKey]"
firebase functions:config:set zoom.apisecret="[apiSecret]"
```
* get the cloud function endpoint from the project page in the firebase console:
* e.g. https://console.firebase.google.com/u/0/project/[project name]/functions/list
* (ends in "zoomSig")
*
* test:
curl --location --request POST 'https://[firebase-cloud-functions-server]/zoomSig' \
--header 'Content-Type: application/json' \
--data-raw '{"meetingNumber": [123456789], "role": 0}'
*
*/
import * as functions from 'firebase-functions';
const cors = require('cors')
const express = require('express');
const app = express();
// // Start writing Firebase Functions
// // https://firebase.google.com/docs/functions/typescript
const crypto = require('crypto') // crypto comes with Node.js
const apiKey = functions.config().zoom.apikey;
const apiSecret = functions.config().zoom.apisecret;
const zoom_GenerateSignature = (meetingNumber:number, role:number):string => {
// Prevent time sync issue between client signature generation and zoom
const timestamp = new Date().getTime() - 30000
const msg = Buffer.from(apiKey + meetingNumber + timestamp + role).toString('base64')
const hash = crypto.createHmac('sha256', apiSecret).update(msg).digest('base64')
const signature = Buffer.from(`${apiKey}.${meetingNumber}.${timestamp}.${role}.${hash}`).toString('base64')
return signature
}
app.use(cors({ origin: true }));
app.post('/', (request:any, response:any) => {
const {meetingNumber, role} = request.body;
// console.log( "zoomSig:", meetingNumber, role , "\nrequest.body=", request.body, "\nrequest", request)
if (!meetingNumber || typeof role != "number") {
response.status(400).send({ message: 'missing meetingNumber or role' });
return
}
const signature:string = zoom_GenerateSignature( meetingNumber, role );
response.send({signature});
});
// // Expose Express API as a single Cloud Function:
export const zoomSig = functions.https.onRequest(app);
/**
* this method works from `curl`, but does NOT work with correctly with CORS. don't know why.
*/
export const zoomSigWithoutExpress = functions.https.onRequest((request, response) => {
if(request.method !== "POST"){
response.status(400).send({ message: 'Please send a POST request'});
return;
}
// cors is NOT working in this example
cors({ origin: true })(request, response, () => {
const {meetingNumber, role} = request.body;
console.log( "zoomSig:", meetingNumber, role , "\nrequest.body=", JSON.stringify(request.body), "\nrequest", request)
if (!meetingNumber || typeof role != "number") {
response.status(400).send({ message: 'missing meetingNumber or role' });
return
}
const signature:string = zoom_GenerateSignature( meetingNumber, role );
response.send({signature});
});
});