Debugging Authentication: Resolving Token Issues in iOS and Android

TL;DR

• Mismanagement in state propagation can make loaders linger indefinitely, suggesting a need to consolidate related states for maintainability.
• Debugging by logging current states is essential to trace how each step in code execution modifies global state variables.
• Handling errors explicitly and pruning unnecessary state checks helps clean up logic and solve bugs.
• Misconfigured ports can break connections. Understanding your environment setup is crucial.
• Auth0 library behavior is poorly documented, causing unexpected credential refresh attempts.
• Refresh tokens must be handled carefully to avoid unwanted logout behavior.

Today, I was deep diving into a perplexing login issue with our DevOps setup. Some users couldn’t log in, facing apparent token exchange failures from Auth0’s perspective. Interestingly, this wasn’t a user-based issue; I managed to change a user’s password and successfully logged in on a different device. Testing across multiple devices showed inconsistency. For instance, an iPhone running iOS 15.7 was unaffected, while another on iOS 16.7.11 kept getting stuck during login.

I initially suspected that it might be library-related issues interacting with older iOS versions. Still, the pattern wasn’t consistent—Mickey’s iOS was older yet functional. Both my iOS 18.5 device and an Android device running version 31 had no issues, ruling out a simple age-related cause.

Moving on, I focused on the possibility that refresh tokens weren’t being handled correctly during logout processes. My plan: examine whether multiple refresh tokens were created or left unsynced. I aimed to log out and back in, monitoring Auth0 interactions closely.

Using dev tools on iOS, I logged out, watched the token-manager’s behavior, and aimed at capturing the logs. Intriguingly, there seemed to be no token-manager interaction as I clicked ’log out’, suggestive of a deeper issue at play. At this point, I paused my experiments due to an unexpected delivery interruption, reflecting the imperfect nature of real-world debugging.

Through these steps, I continue to chase a resolution—logging token steps, ensuring session validity, and keeping my engineering instincts sharp amidst the chaos of interruptions. Stay tuned as the saga unfolds!