Implementing Token Revocation Strategies for Microservices in iOS Security Architecture
I'm converting an old project and I'm trying to figure out Currently developing a suite of microservices where security is paramount, particularly regarding how to handle token revocation without degrading user experience in our iOS applications. We are implementing OAuth 2.0 for user authentication, and I'm keen to explore robust strategies for managing revoked tokens effectively. To ensure a seamless experience, I initially used a simple approach where the app checks token validity against our authentication server each time a critical action is performed. However, this led to noticeable latency, especially during network fluctuations. For example, I had this flow: ```swift func performAction() { checkTokenValidity { isValid in if isValid { // Proceed with action } else { // Prompt re-authentication } } } ``` This method, while secure, became a bottleneck. Recently, I've been experimenting with a caching mechanism where we temporarily store the token’s status after the first check. If a token is revoked, we should ideally update our cache promptly. However, I’m concerned about the implications of caching on security. To mitigate risks, I’ve considered implementing a background task that periodically fetches the status of the token from the server. Here’s a skeletal implementation I worked on: ```swift func startTokenStatusUpdater() { Timer.scheduledTimer(withTimeInterval: 3600, repeats: true) { _ in fetchTokenStatusFromServer() } } func fetchTokenStatusFromServer() { // Network call to check token status } ``` This introduces a balance, but I’m not sure if a 1-hour interval is optimal. Should it be shorter or longer based on user activity? Additionally, I’ve stumbled upon concepts like revocation lists and JWT (JSON Web Tokens) blacklisting, but integrating those into our existing architecture could be challenging. Has anyone successfully implemented a token revocation strategy that minimizes user disruption while ensuring tight security? Would love to hear thoughts on best practices or experiences with specific frameworks or libraries that could aid in this endeavor. Any feedback is welcome! Any examples would be super helpful.