Hi, On Wed, Aug 08, 2018 at 07:58:45PM +0200, Pavel Machek wrote: > On Mon 2018-08-06 18:39:58, joeyli wrote: > > On Mon, Aug 06, 2018 at 04:45:34PM +0800, Yu Chen wrote: > > > Hi Pavel, > > > On Sun, Aug 05, 2018 at 12:02:00PM +0200, Pavel Machek wrote: > > > > Hi! > > > > > > > > > > User space doesn't need to involve. The EFI root key is generated by > > > > > > EFI boot stub and be transfer to kernel. It's stored in EFI boot service > > > > > > variable that it can only be accessed by trusted EFI binary when > > > > > > secure boot is enabled. > > > > > > > > > > > Okay, this apply to the 'suspend' phase, right? > > > > > I'm still a little confused about the 'resume' phase. > > > > > Taking encryption as example(not signature), > > > > > the purpose of doing hibernation encryption is to prevent other users > > > > > from stealing ram content. Say, user A uses a passphrase to generate the > > > > > > > > No, I don't think that's purpose here. > > > > > > > > Purpose here is to prevent user from reading/modifying kernel memory > > > > content on machine he owns. > > > > > > > Say, A puts his laptop into hibernation and walks away, > > > and B walks by, and opens A's laptop and wakes up the system and he > > > can do what he wants. Although EFI key/TPM trusted key is enabled, > > > currently there's no certification during resume, which sounds > > > unsafe to me. Afterall, the original requirement is to probe > > > user for password during resume, which sounds more natural. > > > > OK, I saw your case. This is a physical accessing. > > > > I have a question: The suspend to memory also has the same behavior > > and more people are using suspend. Should we think a common solution > > to cover S3 and S4? > > Well, we have similar problem during runtime, too ;-). > > Anyway, I don't think we should encrypt memory during S3 in kernel. > It seems that Joey was talking about certification(something like login) rather than encryption? Best, Yu > If you wanted to do that, you could use uswsusp to take snapshot, > store it in ram, encrypt, erase originals (new API might be > needed... hmm. does not exactly sound easy... kexec?), trigger S3, decrypt, > resume from snapshot... > > Sounds like a bit of work... > > Best regards, > > Pavel > -- > (english) http://www.livejournal.com/~pavelmachek > (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
