Hi Apple Devs,
For our app, we utilize passkeys for account creation (not MFA). This is mainly for user privacy, as there is 0 PII associated with passkey account creation, but it additionally also satisfies the 4.8: Login Services requirement for the App Store.
However, we're getting blocked in Apple Review. Because the AASA does not get fetched immediately upon app install, the reviewers are not able to create an account immediately via passkeys, and then they reject the build.
I'm optimistic I can mitigate the above. But even if we pass Apple Review, this is a pretty catastrophic issue for user security and experience. There are reports that 5% of users cannot create passkeys immediately (https://developer.apple.com/forums/thread/756740). That is a nontrivial amount of users, and this large of an amount distorts how app developers design onboarding and authentication flows towards less secure experiences:
App developers are incentivized to not require MFA setup on account creation because requiring it causes significant churn, which is bad for user security.
If they continue with it anyways, for mitigation, developers are essentially forced to add in copy into their app saying something along the lines of "We have no ability to force Apple to fetch the config required to continue sign up, so try again in a few minutes, you'll just have to wait."
You can't even implement a fallback method. There's no way to check if the AASA is available before launching the ASAuthorizationController so you can't mitigate a portion of users encountering an error!!
Any app that wants to use the PRF extension to encrypt core functionality (again, good for user privacy) simply cannot exist because the app simply does not work for an unspecified amount of time for a nontrivial portion of users.
It feels like a. Apple should provide a syscall API that we can call to force SWCD to verify the AASA or b. implement a config based on package name for the app store such that the installation will immediately include a verified AASA from Apple's CDN. Flicking the config on would require talking with Apple. If this existed, this entire class of error would go away.
It feels pretty shocking that there isn't a mitigation in place for this already given that it incentivizes app developers to pursue strictly less secure and less private authentication practices.
Topic:
Privacy & Security
SubTopic:
General
Tags:
Authentication Services
Universal Links
Passkeys in iCloud Keychain