I am using the prf extension for passkeys that is available since ios 18 and macos15. I am using a fixed, hardcoded prf input when creating or geting the credentials. After creating a passkey, i try to get the credentials and retrieve the prf output, which works great, but i am getting different prf outputs for the same credential and same prf input used in the following scenarios:
Logging in directly (platform authenticator) on my macbook/iphone/ipad i get “prf output X” consistently for the 3 devices
When i use my iphone/ipad to scan the qr code on my macbook (cross-platform authenticator) i get “prf output Y” consistently with both my ipad and iphone.
Is this intended? Is there a way to get deterministic prf output for both platform and cross-platform auth attachements while using the same credential and prf input?