Secure authentication with tokens

Authentication is the act of validating the identity of each user before they access a system. Agora uses digital tokens to authenticate users and their privileges before they access Agora SD-RTN™ to join a channel. Each token is valid for a limited period and works for specific and wildcard channel names. For example, you use a Agora* token to join AgoraChannel or AgoraAwesome. However, you cannot use it to join the AppTest channel.

This page shows you how to quickly set up an authentication token server, retrieve a token from the server, and use it to connect securely to a IoT SDK channel. You use this server for development purposes. To see how to develop your own token generator and integrate it into your production IAM system, read Token generators.

An authentication token is a dynamic key that is valid for a maximum of 24 hours. On request, a token server returns an authentication token that is valid to join a specific channel or wildcard channels.

When users attempt to connect to an Agora channel, your app retrieves a token from the token server in your security infrastructure. Your app then sends this token to Agora SD-RTN™ for authentication. Agora SD-RTN™ validates the token and reads the user and project information stored in the token. A token contains the following information:

• The App ID of your Agora project

• The App certificate of your Agora project

• The name of an individual channel, or a wildcard string for multiple channels

• The user ID of the user to be authenticated (optional)

• The privilege of the user, either as a publisher or a subscriber

• The Unix timestamp showing when the token will expire

The following figure shows the call flow you need to implement to create step-up-authentication with Agora IoT SDK:

To follow this procedure, you must have:

• Implemented the SDK quickstart

• Created a cloud platform account that is verified through your GitHub account. The following platforms are currently supported:

  • Render
  • Railway
  • Heroku

  To integrate a token generator directly into your security infrastructure, see Token generators.

• Android Studio 4.1 or higher.
• Android SDK API Level 24 or higher.
• A mobile device that runs Android 4.1 or higher.

• An Agora account and project.

• A computer with Internet access.

  Ensure that no firewall is blocking your network communication.

In the SDK quickstart sample project, the app uses an authentication token obtained manually from Agora Console to join a channel. In a production environment, your app retrieves this token from a token server. This section shows you how to:

1. Create and run a token server

2. Authenticate using the SDK

This section shows you how to deploy a token server on a cloud platform.

1. Start deploying the token server to your cloud platform:

   Click your cloud platform below. The cloud platform retrieves the project code and necessary files from Github, then takes you to the Deployment page.

   • Render
   • Railway
   • Heroku

2. Fill in the information needed by your cloud platform:

   1. Blueprint name: A unique name for your deployment.

   2. Branch name: The branch of the repo or fork you want to deploy, default is main.

   3. APP_CERTIFICATE: The App Certificate obtained from Agora Console.

   4. APP_ID: The App ID obtained from Agora Console.

   5. Github account: The GitHub account where the cloud platform should clone the token server repository.

   6. Repository name: The name of the cloned repository, the default is agora-token-service.

   7. Private repository: Select this option to hide this repository.

3. Create your token server:

   Click Deploy. The platform configures and builds the token server.

4. Test your server

   1. Click the URL.

      You are notified of a URL where your server is deployed. Click the link and open the token server in your browser. Don’t worry if you see 404 page not found in your browser. Follow the next steps and test your server.

   2. Send a request to the token server using a URL based on the Token server GET request structure:

      
      

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      /rtc/:channelName/:role/:tokentype/:uid/?expiry=expireTime

      
      

      For example: https://agora-token-server-<your id>.onrender.com/rtc/MyChannel/1/uid/1/?expiry=300

      Your token server returns a JSON object containing an encrypted token:

      
      

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      {"rtcToken":"ThisIsAnExampleTokenThisIsAnExampleTokenThisIsAnExampleTokenThisIsAnExampleTokenThisIsAnExampleToken"}

      
      

1. Specify the token server URL

   In the MainActivity class, declare the following variable to hold the token server URL.

   
   

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   // The base URL to your token server.

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   // For example, "https://agora-token-service-production-92ff.up.railway.app"

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   private String serverUrl = "<Token Server URL>";

   
   

   Make sure you specify the token-server URL in exactly the same format as shown in the example.

2. Set the token URL for AgoraVideoViewer

   To set the token URL, you create an AgoraSettings object, set its TokenURL property and pass this object to the constructor when initializing AgoraVideoViewer. To do this, replace the code in the try {…​} block of the initializeAndJoinChannel() method with the following:

   
   

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   AgoraSettings settings = new AgoraSettings();

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   settings.setTokenURL(serverUrl);

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   agView = new AgoraVideoViewer(this, new AgoraConnectionData(appId, null),

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   AgoraVideoViewer.Style.FLOATING, settings, null);

   
   

3. Fetch a token from the server when you join a channel

   In the joinChannel() method, replace the agView.join call with the following:

   
   

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   agView.join(channelName, true, Constants.CLIENT_ROLE_BROADCASTER, 0);

   
   

To retrieve tokens from the token server and use them to authenticate your app with Agora SD-RTN™ using IoT SDK:

1. Import IoT SDK classes and interfaces:

   
   

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   import io.agora.rtc2.*

   
   

2. Declare variables for your request to the token server:

   
   

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   var serverUrl : String // The base URL to your token server

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   private val tokenExpiryTime : Int // Time in seconds after which the token will expire.

   
   

3. Retrieve a token from the server:

   Use a GET request to retrieve an authentication token for a specific channel from the token server.

   
   

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   fun fetchToken(channelName: String, uid: Int, callback: TokenCallback) {

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   val tokenRole = if (isBroadcaster) 1 else 2

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   // Prepare the Url

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   val urlLString = "$serverUrl/rtc/$channelName/$tokenRole/uid/$uid/?expiry=$tokenExpiryTime"

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   val client = OkHttpClient()

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   // Create a request

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   val request: Request = Builder()

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   .url(urlLString)

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   .header("Content-Type", "application/json; charset=UTF-8")

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   .get()

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   .build()

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   // Send the async http request

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   val call = client.newCall(request)

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   call.enqueue(object : Callback {

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   // Receive the response in a callback

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   @Throws(IOException::class)

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   override fun onResponse(call: Call, response: Response) {

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   if (response.isSuccessful) {

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   try {

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   // Extract rtcToken from the response

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   val responseBody = response.body!!.string()

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   val jsonObject = JSONObject(responseBody)

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   val rtcToken = jsonObject.getString("rtcToken")

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   // Return the token

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   callback.onTokenReceived(rtcToken)

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   } catch (e: JSONException) {

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   e.printStackTrace()

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   callback.onError("Invalid token response")

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   }

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   } else {

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   callback.onError("Token request failed")

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   }

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   }

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   override fun onFailure(call: Call, e: IOException) {

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   callback.onError("IOException: $e")

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   }

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   })

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   }

   
   

4. Join a channel using a token from the token server:

   Use fetchToken to retrieve a token before joining a channel.

   
   

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   fun joinChannelWithToken(channelName: String): Int {

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   if (agoraEngine == null) setupAgoraEngine()

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   return if (isValidURL(serverUrl)) { // A valid server url is available

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   // Fetch a token from the server for channelName

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   fetchToken(channelName, object : TokenCallback {

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   override fun onTokenReceived(rtcToken: String?) {

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   // Handle the received rtcToken

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   joinChannel(channelName, rtcToken)

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   }

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   override fun onError(errorMessage: String) {

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   // Handle the error

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   sendMessage("Error: $errorMessage")

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   }

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   })

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   0

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   } else { // use the token from the config.json file

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   val token = config!!.optString("rtcToken")

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   joinChannel(channelName, token)

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   }

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   }

   
   

5. Renew an expiring token:

   A token expires either after the tokenExpiryTime specified in the call to the token server or, if the time is not specified, after 24 hours. When the onTokenPrivilegeWillExpire event in the IRtcEngineEventHandler receives a callback, you retrieve a fresh token and call renewToken.

   
   

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   // Listen for the event that the token is about to expire

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   override fun onTokenPrivilegeWillExpire(token: String) {

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   sendMessage("Token is about to expire")

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   // Get a new token

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   fetchToken(channelName, object : TokenCallback {

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   override fun onTokenReceived(rtcToken: String?) {

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   // Use the token to renew

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   agoraEngine!!.renewToken(rtcToken)

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   sendMessage("Token renewed")

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   }

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   override fun onError(errorMessage: String) {

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   // Handle the error

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   sendMessage("Error: $errorMessage")

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   }

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   })

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   super.onTokenPrivilegeWillExpire(token)

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   }

   
   

To test the Secure authentication with tokens example:

1. Generate a temporary token in Agora Console.

2. Configure the web demo you use to connect to your app:

   In your browser, navigate to the Agora web demo and update App ID, Channel, and Token with the values for your temporary token, then click Join.

3. Configure your project:

   In agora-manager/res/raw/config.json, update the following:

   • appId - with your app ID from Agora Console.
   • rtcToken - an empty string.
   • serverUrl - with the base URL for your token server. For example: https://agora-token-service-production-yay.up.railway.app.
   • tokenExpiryTime - with an integer denoting the number of seconds after which a token expires.

4. Run the Android reference app:

   1. In Android Studio, connect a physical Android device to your development machine.

   2. Click Run to start the app.

      A moment later you see the project installed on your device. If this is the first time you run the project, you need to grant microphone and camera access to your app.

   3. From the main screen of the app, choose IoT SDK from the dropdown and then select Secure authentication with tokens.

5. Join a Channel:

Your app magically connects to the same channel you used in web demo. You don’t need to hardcode a token in your app; each channel is secured with a specific token, and each token is refreshed automatically. That’s pretty cool!

This section contains information that completes the information in this page, or points you to documentation that explains other aspects to this product.

The token server RESTful web service used in this page is written in Golang using the Gin framework. Want to use the code in your authentication service? Download the token server source code and binaries for various platforms from Github.

To see how to create a token generator inside your IAM system, see Integrate a token generator.

A token server GET request has the following structure:

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/rtc/:channelName/:role/:tokentype/:uid/?expiry=expireTime

• :channelName is the name of the Agora Channel you wish to join

  A channel name may contain numbers with both upper and lower case letters. The name length must be less than 64 characters.

• :role is the user role

  Use publisher for publisher, subscriber for subscriber.

• :tokentype is the type of token

  Agora SD-RTN™ supports both integer user IDs and string user accounts for token generation. To ensure smooth communication, all the users in a channel must use the same type of ID, that is, either the integer uid, or a string userAccount. Best practice is to use the uid.

• :uid is the user ID

  User Id can be any 32-bit unsigned integer. It can be set to 0, if you do not need to authenticate the user based on the user ID.

• expireTime (optional) is the number of seconds after which the token will expire

  By default, a token expires after 24 hours unless a shorter life span is explicitly specified in the token request.

• renewToken
• onTokenPrivilegeWillExpire