It's unexpected to anyone with intuition about how a computer traditionally is supposed to work. As a general principle, as a user, I expect a file on one computer to be usable on another computer. Or, at the very least, if I need to obtain some other thing from the original computer to "unlock" that file, I should be able to do it. The idea of a file that is only usable on a particular computer feels weird.
I think it's time to update your expectations. Hardware security modules have been around for quite a while. You shouldn't assume that your chosen password is the only input to the key derivation, or even that the raw key itself will always be obtainable.
I never assumed that my chosen password was the only input to the key derivation. Just that my chosen password is at least one of the inputs to the key derivation. LUKS has been around for quite a while.
Yes, that's kind of what you need to be able to successfully back up and restore an encrypted file. Why are you making it sound like that's such a strange thing to want?
Yes, in general that's how I expect (or at least want) things to work. And I'm a tech-savvy software developer.
Your average non-technical user will absolutely expect it to work this way, and if it doesn't, will be at best confused, and at worst incredibly angry that their photos are gone.
The sane way for encryption keys stored in hardware (secure enclave or tpm like) is to onboard user when the key is not derived from user password. Just like they do for FDE to export a recovery key and then you can adjust your expectations when you know (been told) whats going on.
> You can export your passwords to a plain text CSV from the original computer.
Exporting a private key from a keychain is hard to automate (the password of the keychain is asked for all exports, and HAS to be typed manually IIRC).
