linux-kernel - Re: Linux DRTM on UEFI platforms

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 7 Jul 2022 05:46:40 -0400
From:   "Daniel P. Smith" <dpsmith@...rtussolutions.com>
To:     The development of GNU GRUB <grub-devel@....org>,
        Brendan Trotter <btrotter@...il.com>
Cc:     Ard Biesheuvel <ardb@...nel.org>,
        Matthew Garrett <mjg59@...f.ucam.org>,
        Daniel Kiper <daniel.kiper@...cle.com>,
        Alec Brown <alec.r.brown@...cle.com>,
        Kanth Ghatraju <kanth.ghatraju@...cle.com>,
        Ross Philipson <ross.philipson@...cle.com>,
        "piotr.krol@...eb.com" <piotr.krol@...eb.com>,
        "krystian.hebel@...eb.com" <krystian.hebel@...eb.com>,
        "persaur@...il.com" <persaur@...il.com>,
        "Yoder, Stuart" <stuart.yoder@....com>,
        Andrew Cooper <andrew.cooper3@...rix.com>,
        "michal.zygowski@...eb.com" <michal.zygowski@...eb.com>,
        James Bottomley <James.Bottomley@...senpartnership.com>,
        "lukasz@...rylko.pl" <lukasz@...rylko.pl>,
        linux-efi@...r.kernel.org, linux-kernel@...r.kernel.org,
        James Morris <jmorris@...ei.org>
Subject: Re: Linux DRTM on UEFI platforms

On 7/5/22 20:03, Brendan Trotter wrote:
> Hi,

Greetings!

Not sure why I got dropped from distro, but no worries.

> On Wed, Jul 6, 2022 at 4:52 AM Daniel P. Smith
> <dpsmith@...rtussolutions.com> wrote:
>> On 6/10/22 12:40, Ard Biesheuvel wrote:> On Thu, 19 May 2022 at 22:59,
>> To help provide clarity, consider the following flows for comparison,
>>
>> Normal/existing efi-stub:
>>    EFI -> efi-stub -> head_64.S
>>
>> Proposed secure launch:
>>    EFI -> efi-stub -> dl-handler -> [cpu] -> sl_stub ->head_64.S
> 
> For more clarity; the entire point is to ensure that the kernel only
> has to trust itself and the CPU/TPM hardware (and does not have to
> trust a potentially malicious boot loader)..Any attempt to avoid a
> one-off solution for Linux is an attempt to weaken security.

Please elaborate so I might understand how this entrypoint allows for 
the kernel to only trust itself and the CPU/TPM.

> The only correct approach is "efi-stub -> head_64.S -> kernel's own
> secure init"; where (on UEFI systems) neither GRUB nor Trenchboot has
> a valid reason to exist and should never be installed.
> 
> 
> Cheers,
> 
> Brendan

v/r,
dps