JWT Authentication

Overview

JWT (JSON Web Token) authentication is a standard method for securely verifying user identity. By implementing JWT authentication, you add a critical layer of security to your data collection process with MoEngage.

The feature ensures that the data sent on behalf of your identified users is authentic and has not been tampered with. This security is achieved by requiring a token that is cryptographically signed by your own server, which prevents unauthorized users from impersonating your legitimate users.

Prerequisites

Before you begin the implementation, please ensure you meet the following requirements:

• Your application must use the MoEngage iOS SDK version 10.08.0 or higher to access the JWT authentication feature.
• You must have access to your MoEngage dashboard to manage public keys and configure the feature’s enforcement settings.

The following diagram illustrates the interaction between your application, your server, the MoEngage SDK, and the MoEngage server:

Integration

Follow these steps to integrate JWT authentication into your iOS application.

Step 1: Enable JWT Authentication

You can enable JWT authentication during SDK initialization by configuring the networkConfig.authorizationConfig property on the MoEngageSDKConfig object.

Swift

let sdkConfig = MoEngageSDKConfig(appId: "", dataCenter: .YOUR_DATA_CENTER)
sdkConfig.networkConfig = MoEngageNetworkRequestConfig(authorizationConfig: MoEngageNetworkAuthorizationConfig(isJwtEnabled: true))
#if DEBUG
MoEngage.sharedInstance.initializeDefaultTestInstance(sdkConfig)
#else
MoEngage.sharedInstance.initializeDefaultLiveInstance(sdkConfig)
#endif

Step 2: Pass the JWT to the SDK

Your application is responsible for managing the JWT lifecycle. The recommended flow is to fetch a token upon user login and pass the token to the SDK. You should also check if the token has expired on subsequent app launches and fetch a new one if necessary.

Use the MoEngageSDKCore.passAuthenticationDetails() method to provide the token to the SDK.

Swift

let jwtDetails = MoEngageJwtAuthenticationDetails(token: "your_jwt_token", identifier: "user_id")
MoEngageSDKCore.sharedInstance.passAuthenticationDetails(jwtDetails)

Step 3: Handle Authentication Errors

To handle token validation errors that the MoEngage server returns, you must register an error listener using MoEngageSDKCore.registerAuthenticationListener() method. The SDK invokes this listener when an authentication error occurs, which allows your application to fetch and provide a new token.

Swift

class JwtAuthenticationListener: NSObject, MoEngageAuthenticationError.Listener {
    func onError(_ error: MoEngageAuthenticationError) {
        print("Authentication Error Received:")
        if let jwtError = error as? MoEngageJwtAuthenticationError {
            print("- Code: \(jwtError.details.code.rawValue) - \(jwtError.details.code.description)")
            print("- Token: \(jwtError.details.token == nil ? "No token" : String(jwtError.details.token!.prefix(20)) + "...")")
            print("- Identifier: \(jwtError.details.identifier == nil ? "No identifier" : jwtError.details.identifier!)")
            print("- Message: \(jwtError.details.message ?? "No message")")
        } else {
            print("- Message: \(error.details.message ?? "No message")")
        }
        print("- Account: \(error.accountMeta.appID)")
    }
}
// Register listner after SDK initialization
let listener = JwtAuthenticationListener()
MoEngageSDKCore.sharedInstance.registerAuthenticationListener(listener)

Step 4: Register the listener after SDK initialization

Register the MoEngageAuthenticationError.Listener in a global scope, such as the applicaton(_:didFinishLaunchingWithOptions:) method of your AppDelegate class, to ensure your application always receives callbacks.

Swift

let listener = JwtAuthenticationListener()
MoEngageSDKCore.sharedInstance.registerAuthenticationListener(listener)

Information

• If an API request fails due to an authentication error, the SDK will not retry the request until your application provides a new token.
• After 10 consecutive authentication failures in a single session, the SDK will stop attempting to sync data until the next session begins. This counter resets after any successful sync.
• Upon user logout, if a data sync fails due to a JWT error, the pending data will be deleted, and no retry will be attempted.