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From: "Jason A. Donenfeld" <Jason@zx2c4.com>
To: Ard Biesheuvel <ardb@kernel.org>
Cc: linux-efi@vger.kernel.org,
	Ilias Apalodimas <ilias.apalodimas@linaro.org>,
	Lennart Poettering <lennart@poettering.net>
Subject: Re: [PATCH v3 0/3] efi: consume random seed provided by loader
Date: Thu, 20 Oct 2022 11:16:54 -0600	[thread overview]
Message-ID: <Y1GChlADTKNw94pX@zx2c4.com> (raw)
In-Reply-To: <CAMj1kXGomAd153exTz_m=UANmybqait2eQeqy3n5UAUpU=xCFw@mail.gmail.com>

On Thu, Oct 20, 2022 at 07:06:33PM +0200, Ard Biesheuvel wrote:
> On Thu, 20 Oct 2022 at 18:37, Jason A. Donenfeld <Jason@zx2c4.com> wrote:
> >
> > On Thu, Oct 20, 2022 at 2:40 AM Ard Biesheuvel <ardb@kernel.org> wrote:
> > > For maximum simplicity, just concatenate the existing seed with the one
> > > obtained from EFI_RNG_PROTOCOL if both are available, and leave it to
> > > the core kernel code to mix it in and credit it appropriately. This way,
> > > we have no need for copies of the Blake2s library in the EFI stub and in
> > > the zboot decompressor.
> >
> > FTR, while I think this is okay for the final stage that the kernel's
> > EFI loader does, it's less good for earlier stages. So, for example,
> > systemd-boot should still use the hashing scheme we discussed.
> 
> Not sure I follow. systemd-boot will put a seed in memory and publish
> it via the the table. How does hashing come into play here?

If systemd-boot is executed by another bootloader.

  reply	other threads:[~2022-10-20 17:17 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-20  8:39 [PATCH v3 0/3] efi: consume random seed provided by loader Ard Biesheuvel
2022-10-20  8:39 ` [PATCH v3 1/3] efi: random: reduce seed size to 32 bytes Ard Biesheuvel
2022-10-21  8:38   ` Ilias Apalodimas
2022-10-20  8:39 ` [PATCH v3 2/3] efi: random: Use 'ACPI reclaim' memory for random seed Ard Biesheuvel
2022-10-21  8:37   ` Ilias Apalodimas
2022-10-20  8:39 ` [PATCH v3 3/3] efi: random: combine bootloader provided RNG seed with RNG protocol output Ard Biesheuvel
2022-10-20 16:56   ` Jason A. Donenfeld
2022-10-20 17:11     ` Ard Biesheuvel
2022-10-20 17:22       ` Jason A. Donenfeld
2022-10-20 16:37 ` [PATCH v3 0/3] efi: consume random seed provided by loader Jason A. Donenfeld
2022-10-20 17:06   ` Ard Biesheuvel
2022-10-20 17:16     ` Jason A. Donenfeld [this message]
2022-10-20 17:27       ` Ard Biesheuvel
2022-10-20 17:35         ` Jason A. Donenfeld

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