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.
But that’s not backup restore? I’m thinking Time Machine restore on a new Mac when old one is no longer working. Or when the old one had to be wiped and restored.
What information from your login keychain do you expect to need on your new computer?
There's not really a plausible answer to that question, because the login keychain data is almost entirely specific to that host.
To iron-man your argument: Apps that store account credentials to third party services will need to be signed in again.
If you were using http basic auth for a website and saving that, then it was probably in there.
Private keys and certificates you manually imported, or that were created by an application for your host. This is the closest to a plausible answer, imo.
Can you clone or sync hardware keys? Maybe they don't fail as much as computers do but they can be lost or stolen like the keys that we use to open (dumb) doors.
My non hardware key is a keypass file that I update only on my laptop and I sync to my other devices. I have plenty of backups. It does also the TOTP required to login into some customers servers.
IIRC there are options for exportable and un-exportable private keys when you make one in the secure enclave. Going to guess Tahoe made them un-exportable by default.
There is no way to export data out of secure enclave. You cannot write arbitrary data to secure enclave, as well as read it out.
What happen though is the ability to encrypt the data with secure enclave, store it on our own. When migrating, we decrypt with secure enclave, get back original data and re-encryp on the new device.
As far as I know, you have never been able to import or export keys from the Secure Enclave. It’s more likely that previously keys were stored in the keychain and now they are generated in the SE by default.
Yes you can make private keys that are encrypted by the secure enclave, rather than stored inside it. The "sc_auth" tool on macos has a "ssh-exportable" variant
Disturbing if true, as it suggests my "everything" backups aren't really full backups at all.
I wonder, if you have enabled iCloud keychain, does that provide another way to get your passwords back?
Suppose my MacBook is stolen, but I still have my iPhone. Could I use the passwords app on the iPhone to retrieve my passwords. Would that include all of them or only a subset?
This is so critical. Not just verifying the hashes, not just restoring, but actually booting into it and opening the top 5-10 things you're going to care about.
If it's your personal stuff, skip it at your own peril. If it's a paid responsibility, that's what hourly billing is for (this incentive was much stronger when I learned netadmin, back before nvmes)
I have no idea which keychain is in which, but the last time I migrated from one Apple laptop to another, I couldn't get the automated tool to work at all, so I restored a physical backup, went through the sign-in process, and passwords and passkeys migrated correctly.
Does the macoOS login keychain get backed up by Time Machine backups in a way that could restore the keychain if the original machine's Secure Enclave is lost or destroyed?
It sounds like they are using envelope encryption and using the Secure Enclave to derive the row keys each time. Not really any easy way around that except they should provide a tool to export it, TBH. I am guessing they weren’t using envelope encryption before or they were deriving the row keys from the password. This is a secure design but more security usually means less usability these days.
It's always a good idea to plan to hang on to your old machine for a few weeks to ensure everything works properly on the new one. Apple makes that much easier to forget.
And yet if you click export it will gladly print out a plaintext csv with your whole life in passwords. Doesn't even attempt to zip it with password or something.
that seems reasonable, as it is the lowest common denominator for interoperability
what would be unfortunate is if it was in some format that couldn't be used by most other systems without extra work, and if the user wasn't able to use their own property to export their own passwords in a different format.
As a general rule, I expect a file on an encrypted disk to be unreadable for anyone who lacks the encryption key(s).
> if I need to obtain some other thing from the original computer to "unlock" that file, I should be able to do it.
You can export your passwords to a plain text CSV from the original computer.
There's not really a plausible answer to that question, because the login keychain data is almost entirely specific to that host.
To iron-man your argument: Apps that store account credentials to third party services will need to be signed in again.
If you were using http basic auth for a website and saving that, then it was probably in there.
Private keys and certificates you manually imported, or that were created by an application for your host. This is the closest to a plausible answer, imo.
Hardware keys are the way:
- Less likely to fail in the first place
- Cheap enough to have several of so you can use one to log in and manage the others in the event of loss
- Easy to move between devices
- Less likely to use the auth handshake as a side channel for things you didn't consent to
My non hardware key is a keypass file that I update only on my laptop and I sync to my other devices. I have plenty of backups. It does also the TOTP required to login into some customers servers.
What happen though is the ability to encrypt the data with secure enclave, store it on our own. When migrating, we decrypt with secure enclave, get back original data and re-encryp on the new device.
No, it's not, and that's not how it ever worked in macOS 26.3 and earlier.
This change was introduced in 26.4 for some reason.
I wonder, if you have enabled iCloud keychain, does that provide another way to get your passwords back?
Suppose my MacBook is stolen, but I still have my iPhone. Could I use the passwords app on the iPhone to retrieve my passwords. Would that include all of them or only a subset?
If it's your personal stuff, skip it at your own peril. If it's a paid responsibility, that's what hourly billing is for (this incentive was much stronger when I learned netadmin, back before nvmes)
Yes
> in a way that could restore the keychain if the original machine's Secure Enclave is lost or destroyed?
Apparently not
what would be unfortunate is if it was in some format that couldn't be used by most other systems without extra work, and if the user wasn't able to use their own property to export their own passwords in a different format.