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Jhsto 8 minutes ago [-]
Switching from macOS to Linux was quite painful because the security was so seamless on Mac. But I also realized I had no idea how my passwords are stored and under what guarantees. Learning and getting the hardware tokens to do it properly on Linux was a PITA. But reading this post made me feel a pinch better.
xmddmx 3 hours ago [-]
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?
orbital-decay 2 hours ago [-]
You don't have any backups at all if you never tried restoring and testing them
monster_truck 1 hours ago [-]
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)
lapcat 2 hours ago [-]
The iCloud keychain is separate from the login keychain. The Passwords app doesn't use the login keychain.
amluto 22 minutes ago [-]
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.
xmddmx 55 minutes ago [-]
Even more confusing. Do we know which data is in which keychain?
lapcat 41 minutes ago [-]
Look in the Keychain Access app.
shenenee 4 hours ago [-]
This is pretty much how it's suppose to work...
winstonwinston 4 hours ago [-]
Maybe but this is unexpected if you need to restore from a backup..
wl 8 minutes ago [-]
It's also unexpected when you send your laptop in for a screen replacement, the tech does an unnecessary logic board swap while he's at it, and your local keychain doesn't work anymore. And then Apple Support will say, hey, we told you you needed to backup your data! Which you did, but that's not the issue.
Use iCloud Keychain or don't use Keychain at all.
ryandrake 3 hours ago [-]
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.
GeekyBear 3 hours ago [-]
> As a general principle, as a user, I expect a file on one computer to be usable on another computer.
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.
shaky-carrousel 3 hours ago [-]
As a general rule, I expect a file on an encrypted disk to be encrypted with a key derived from a password I provide.
wtallis 2 hours ago [-]
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.
shaky-carrousel 48 minutes ago [-]
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.
wtallis 37 minutes ago [-]
You're asking for the encryption key to be derivable by an unrelated system that only has the encrypted file and your password.
ftchd 3 hours ago [-]
As a general rule, if I'm the user of both disks I expect to have the encryption key(s).
josephcsible 2 hours ago [-]
The right way to do that is FDE, where you can't even mount the filesystem to see the files without having the decryption key.
petronic 4 hours ago [-]
I've done Tahoe-to-Tahoe migration assistant moves between machines in recent months. No issues with login keychain migration.
winstonwinston 4 hours ago [-]
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.
lapcat 3 hours ago [-]
Migration Assistant uses the old Mac, which can unlock its login keychain and allow the keychain items to be copied.
pmontra 2 hours ago [-]
What if the old Mac is dead, stolen, lost? Those are the scenarios in which one recovers on a new machine from a backup.
awakeasleep 2 hours ago [-]
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.
lapcat 2 hours ago [-]
Then you're in trouble.
Angostura 1 hours ago [-]
Migration assistant can also use a TM backup, I’m pretty sure
__MatrixMan__ 4 hours ago [-]
Don't backup keys, rotate them.
gavinsyancey 3 hours ago [-]
I can't rotate my keys if I lose access to accounts because my computer died and my backup is useless.
__MatrixMan__ 3 hours ago [-]
Yeah, that's why secure enclaves embedded in complex devices are a bad idea.
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
pmontra 2 hours ago [-]
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.
Retr0id 4 hours ago [-]
I'm more interested by the fact that it apparently didn't work this way before Tahoe.
pram 4 hours ago [-]
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.
kureikain 16 minutes ago [-]
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.
what 3 hours ago [-]
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.
pram 2 hours ago [-]
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
4 hours ago [-]
lapcat 1 hours ago [-]
> This is pretty much how it's suppose to work...
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.
3 hours ago [-]
dfabulich 4 hours ago [-]
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?
3 hours ago [-]
lapcat 3 hours ago [-]
Does the macoOS login keychain get backed up by Time Machine backups
Yes
> in a way that could restore the keychain if the original machine's Secure Enclave is lost or destroyed?
Apparently not
dfabulich 2 hours ago [-]
"Apparently"? Is this something that can be tested with VMs?
lapcat 2 hours ago [-]
I've tested with VMs. However, I'm unclear about the relationship if any between VMs and the secure enclave.
ok_dad 2 hours ago [-]
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.
tencentshill 2 hours ago [-]
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.
ImPostingOnHN 3 hours ago [-]
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.
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)
Use iCloud Keychain or don't use Keychain at all.
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.
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.