Bug 230901 – REGRESSION (iOS 15): Slow response to WebAuthn calls

• Status: RESOLVED
• Resolution: MOVED
• Component: WebKit Misc.

We're seeing some slowness in WebAuthn call invocations in some devices after updating to iOS15. In trying to isolate the issue we saw was that querying the platform whether there's a biometric authenticator -- by evaluating window.PublicKeyCredential.isUserVerifyingPlatformAuthenticatorAvailable().then(alert); in the developer tools console while in any site, e.g,  in google.com, takes roughly 30 seconds to respond. Moreover, this happens even if we disabled passcode and face ID (which means it takes the browser roughly 30 seconds to respond that there's no platform authenticator supported). Note that we also saw slowness in other FIDO calls but this is a "minimal reproducible test" we have. 

This happens only in some devices. Most devices work as expected and respond immediately. Out of the devices where this occurs, in some this went away after rebooting the device. We have access to at least one device where this consistently happens even after reboot. We don't have clear data on how frequent this is.

Those devices were never connected to Xcode, so we believe the new "synchronized platform credentials" should be turned off there. Also no private relay is used. No experimental feature setting different from the "working" devices. Clear website data etc didn't work. Didn't try to reset device data completely.

[Radar WebKit Bug Importer]

<rdar://problem/83684920>

[Brent Fulgham]

This is actually:
<rdar://problem/83707927>

[Brent Fulgham]

Actually -- this is really:
<rdar://82279118>

The fix for this issue was needed outside the WebKit project, therefore this is being resolved as 'Moved'.

[Brent Fulgham]

This should be resolved in macOS 12.2