Secure channel encryption

Updated

Add Agora built-in media stream encryption method to your app.

Media stream encryption encrypts audio and video streams with a unique key and salt controlled by your app server. Encryption ensures that only authorized users in a channel can see and hear each other.

This article describes how to integrate Agora built-in media stream encryption into your app.

Understand the tech

The following figure illustrates data transfer with media stream encryption enabled.

Data transfer process

Prerequisites

Ensure that you have implemented the SDK quickstart in your project.

Implement media stream encryption

To add built-in media stream encryption to your app, refer to the following steps.

  1. Generate a key and salt on your server.

    To generate a random 32-byte hexadecimal key on your server as a string, run:

    openssl rand -hex 32

    To generate a random Base64-encoded, 32-byte salt on your server, run:

    openssl rand -base64 32
  2. Implement client-side logic.

All users in a channel must use the same encryption mode, key, and salt. Discrepancies may lead to unexpected behavior, such as black screens or audio loss.

To ensure security, use a new key and salt each time you enable media stream encryption.

Obtain the string key and Base64-encoded salt from your server, convert the salt to a 32-byte array, and call enableEncryption before joining a channel. Set the encryption mode to Aes128Gcm2 or Aes256Gcm2 and pass the key and salt to the SDK.

const encryptionMode = EncryptionMode.Aes128Gcm2;
const encryptionKey = await getEncryptionKeyFromServer();
const encryptionKdfSalt = await getEncryptionSaltBytesFromServer();

if (!encryptionKey) {
  throw new Error('encryptionKey is invalid');
}

rtcEngine.enableEncryption(true, {
  encryptionMode,
  encryptionKey,
  encryptionKdfSalt,
});

Reference

Sample projects

API reference