Mailinglist Archive: opensuse-factory (355 mails)

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Re: [opensuse-factory] Will openSUSE adopt systemd-homed?
  • From: Chris Murphy <lists@xxxxxxxxxxxxxxxxx>
  • Date: Wed, 18 Mar 2020 16:26:51 -0600
  • Message-id: <>
On Wed, Mar 18, 2020 at 6:52 AM Christian Dywan <cdywan@xxxxxxx> wrote:

I have a surprisingly simple use case:

The data I care about lives in my ~, e.g. /home/rumo, which includes
podman containers, FlatPak apps and network settings and things like
that. And I even have other users on that same machine. I prefer not to
share any passwords if I can help it.

Note that I'm referring to the actual home. There is little point in
encrypting the entirety of /home in this context from my perspective.

It's important to locate user data leaking outside of ~/ and ask they
be relocated appropriately. This could be ~/.var instead of /var for
data that needs to be persistent. And /run/user/* for transient data.
User data shouldn't be leaking to /tmp for the same reason it
shouldn't leak into /var/tmp, but at least /tmp could be (or even
should be) on tmpfs so that at least the leakage is transient and less
of a problem.

I wonder if the systemd-journald user- logs should instead go into
~/.var or /run, at least I'd like to hear a security expert's risk
assessment. As all these things are degrees of risk.

For swap, it's a bit more tricky but until there's a Secure Boot
compatible signed+encrypted swap implementation: a) swap-on-ZRAM, at
least it's transient b) /dev/urandom generated key at each boot for
use with a conventional swapfile c) (approximately) full disk

These days I'm fond of swap-on-ZRAM using upstream zram-generator; but
if your use case has substantial swap need, use a conventional swap
combined with zswap, which helps moderate the performance hit of the
transition to swap usage.

Also, systemd-homed does support Btrfs subvolumes for user homes. If
full disk encryption is chosen, this is what would be used. If full
disk encryption isn't chosen, then encrypt user homes using LUKS
encrypted loop mounted files. Due to complicated a11y and i18n issues
in the pre-boot (GRUB) and early boot (plymouth/initramfs)
environments, I'm more in favor of ~/ encryption by default.

Chris Murphy
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