Hey everyone, here’s an idea, what do you think? (Please stop me…)
I have a few remote servers where disk encryption is only a moderately important measure; I definitely want to keep it but I’m also annoyed by having to ssh into it during the initrd-phase to provide a passkey on every reboot. What I would like is to get a notification with a link to my idp for some device flow, allowing me to authorize the server to obtain the secrets necessary for decryption.
As far as I can tell, this hasn’t been done before, or have I missed something? A naive idea would be to have custom oidc-claims for the different servers where the value is the luks-passphrase. Feels like a bad idea, though. Any ideas on the details as to how? I obviously don’t want to bloat my initrd-image, so a bash script using curl would be ideal.
It wasn’t clear to me at first glance how the mandos server gets the approval to supply the client with its desired key, but I figured it out in the meantime: that’s done through the mandos-monitor tui. However, that doesn’t quite fit my ux-expectations. Thanks for mentioning it, though. It’s an interesting project I will keep in mind.
Ehmmmm I still don’t grasp what you mean.
In any case, mandos has a possibility to do it automatically via rsa encryption, so you have the possibility of totally unattended restart.
Because the server is (ideally) in a different location, if one of yiur systems is stolen / compromised then you only delete / revoked the certificates ID and then that machine would not be able to decrypt its own luks system.
I never deployed this system on my own, but I know a few guys who did it
Regards