On 10/8/21 10:56 AM, Stefan Berger wrote:
On 10/8/21 10:52 AM, Daniel P. Berrangé wrote:
On Fri, Oct 08, 2021 at 09:56:35AM -0400, Stefan Berger wrote:
Using swtpm v0.7.0 we can run swtpm_setup to create default config
files
for swtpm_setup and swtpm-localca in session mode. Now a user can start
a VM with an attached TPM without having to run this program on the
command line before. This program needs to run once.
This patch addresses the issue raised in
https://bugzilla.redhat.com/show_bug.cgi?id=2010649
BTW, I notice the this tool creates certs under $HOME/.config/var
with an expiry date of +10 years.
Now that sounds like a long time, and indeed it is a long time,
but then I look at the support lifetime of RHEL... Hopefully
bare metal hardware won't last for the whole 10 years without
being replaced, but with nested virt the "hosts" could be VMs
that get moved to new hardware.
So what's the story if a host hits the 10 year mark for the
swtpm certs ? Presumably swtpm is validating these dates
and will refuse to launch the TPM for the VMs on the host ?
It doesn't.
I am switching to non-expiring certificates now which should help
address this issue for future CAs.
These CAs 'created on the fly' were thought of merely as a convenience
for the user and someone more serious about the TPM CAs would create
them on their own and use appropriate dates for the expiration and
manage these certificates before they expire. In a larger setting all
hosts should share a fairly well-known TPM CA so that all vTPMs'
certificates are signed with the same CA and certificate validators
don't need to have n hosts' certs but just '1'. However, that requires
setup by an admin rather than relying on CAs 'created on the fly'.
Thanks for the feedback
Stefan
Regards,
Daniel
