Re: [RFC PATCH 00/18 v3] Signature verification of hibernatesnapshot

From: Pavel Machek
Date: Thu Aug 29 2013 - 17:33:01 EST


Hi!

> > > - Bootloader store the public key to EFI boottime variable by itself
> > > - Bootloader put The private key to S4SignKey EFI variable for forward to
> > > kernel.
> >
> > Is the UEFI NVRAM really suited for such regular updates?
> >
>
> Yes, Matthew raised this concern at before. I modified patch to load
> private key in efi stub kernel, before ExitBootServices(), that means we
> don't need generate key-pair at every system boot. So, the above
> procedure of efi bootloader will only run one time.
>
> User can enable SNAPSHOT_REGEN_KEYS kernel config to notify efi
> booloader regenerate key-pair for every S4 to improve security if he
> want. So, the key-pair re-generate procedure will only launched when S4
> resume, not every system boot.

How many writes can UEFI NVRAM survive? (Is it NOR?)

"every S4 resume" may be approximately "every boot" for some users...
Pavel
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