From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
To: "Lee, Chun-Yi" <joeyli.kernel@gmail.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-efi <linux-efi@vger.kernel.org>,
"the arch/x86 maintainers" <x86@kernel.org>,
keyrings@vger.kernel.org,
linux-integrity <linux-integrity@vger.kernel.org>,
"Lee, Chun-Yi" <jlee@suse.com>, Kees Cook <keescook@chromium.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
Pavel Machek <pavel@ucw.cz>, Chen Yu <yu.c.chen@intel.com>,
Oliver Neukum <oneukum@suse.com>,
Ryan Chen <yu.chen.surf@gmail.com>,
David Howells <dhowells@redhat.com>,
Mimi Zohar <zohar@linux.vnet.ibm.com>
Subject: Re: [PATCH 0/6][RFC] Add EFI secure key to key retention service
Date: Sun, 5 Aug 2018 09:25:56 +0200 [thread overview]
Message-ID: <CAKv+Gu81vEGNggcWv1NyPJsMeK0HRi_DanH2+Z_4metoNG=txA@mail.gmail.com> (raw)
In-Reply-To: <20180805032119.20485-1-jlee@suse.com>
Hello Chun,yi,
On 5 August 2018 at 05:21, Lee, Chun-Yi <joeyli.kernel@gmail.com> wrote:
> When secure boot is enabled, only signed EFI binary can access
> EFI boot service variable before ExitBootService. Which means that
> the EFI boot service variable is secure.
>
No it, isn't, and this is a very dangerous assumption to make.
'Secure' means different things to different people. 'Secure boot' is
a misnomer, since it is too vague: it should be called 'authenticated
boot', and the catch is that authentication using public-key crypto
does not involve secrets at all. The UEFI variable store was not
designed with confidentiality in mind, and assuming [given the
reputation of EFI on the implementation side] that you can use it to
keep secrets is rather unwise imho.
> This patch set add functions to EFI boot stub to generate a 512-bit
> random number that it can be used as a root key for encryption and
> authentication. This root key will be kept in EFI boot service variable.
> EFI boot stub will read and transfer ERK (efi root key) to kernel.
>
> At runtime, the ERK can be used to encrypted/authentication other
> random number to generate EFI secure key. The EFI secure key can be
> a new master key type for encrypted key. It's useful for hibernation
> or evm.
>
> Here is the proof of concept for using EFI secure key in hibernation:
> https://github.com/joeyli/linux-s4sign/commit/6311e97038974bc5de8121769fb4d34470009566
>
> Cc: Kees Cook <keescook@chromium.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: "H. Peter Anvin" <hpa@zytor.com>
> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
> Cc: Pavel Machek <pavel@ucw.cz>
> Cc: Chen Yu <yu.c.chen@intel.com>
> Cc: Oliver Neukum <oneukum@suse.com>
> Cc: Ryan Chen <yu.chen.surf@gmail.com>
> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> Cc: David Howells <dhowells@redhat.com>
> Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
> Signed-off-by: "Lee, Chun-Yi" <jlee@suse.com>
>
> Lee, Chun-Yi (6):
> x86/KASLR: make getting random long number function public
> efi: the function transfers status to string
> efi: generate efi root key in EFI boot stub
> key: add EFI secure key type
> key: add EFI secure key as a master key type
> key: enforce the secure boot checking when loading efi root key
>
> Documentation/admin-guide/kernel-parameters.txt | 6 +
> arch/x86/boot/compressed/Makefile | 1 +
> arch/x86/boot/compressed/cpuflags.c | 2 +-
> arch/x86/boot/compressed/eboot.c | 2 +
> arch/x86/boot/compressed/efi_root_key.c | 212 +++++++
> arch/x86/boot/compressed/kaslr.c | 21 -
> arch/x86/boot/compressed/misc.c | 17 +
> arch/x86/boot/compressed/misc.h | 12 +-
> arch/x86/include/asm/efi.h | 13 +
> arch/x86/include/uapi/asm/bootparam.h | 1 +
> arch/x86/kernel/setup.c | 3 +
> arch/x86/lib/kaslr.c | 61 +-
> arch/x86/lib/random.c | 68 +++
> drivers/firmware/efi/Kconfig | 31 +
> drivers/firmware/efi/Makefile | 1 +
> drivers/firmware/efi/efi-secure-key.c | 748 ++++++++++++++++++++++++
> include/keys/efi-type.h | 57 ++
> include/linux/efi.h | 40 ++
> include/linux/kernel.h | 3 +-
> kernel/panic.c | 1 +
> security/keys/encrypted-keys/encrypted.c | 10 +
> 21 files changed, 1226 insertions(+), 84 deletions(-)
> create mode 100644 arch/x86/boot/compressed/efi_root_key.c
> create mode 100644 arch/x86/lib/random.c
> create mode 100644 drivers/firmware/efi/efi-secure-key.c
> create mode 100644 include/keys/efi-type.h
>
> --
> 2.13.6
>
next prev parent reply other threads:[~2018-08-05 7:26 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-05 3:21 [PATCH 0/6][RFC] Add EFI secure key to key retention service Lee, Chun-Yi
2018-08-05 3:21 ` [PATCH 1/6] x86/KASLR: make getting random long number function public Lee, Chun-Yi
2018-08-05 8:16 ` Ard Biesheuvel
2018-08-05 14:40 ` joeyli
2018-08-05 3:21 ` [PATCH 2/6] efi: the function transfers status to string Lee, Chun-Yi
2018-08-05 8:17 ` Ard Biesheuvel
2018-08-05 3:21 ` [PATCH 3/6] efi: generate efi root key in EFI boot stub Lee, Chun-Yi
2018-08-05 3:21 ` [PATCH 4/6] key: add EFI secure key type Lee, Chun-Yi
2018-08-05 3:21 ` [PATCH 5/6] key: add EFI secure key as a master " Lee, Chun-Yi
2018-08-05 3:21 ` [PATCH 6/6] key: enforce the secure boot checking when loading efi root key Lee, Chun-Yi
2018-08-05 7:25 ` Ard Biesheuvel [this message]
2018-08-05 16:31 ` [PATCH 0/6][RFC] Add EFI secure key to key retention service joeyli
2018-08-05 19:00 ` Ard Biesheuvel
2018-08-05 17:47 ` James Bottomley
2018-08-06 6:00 ` joeyli
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAKv+Gu81vEGNggcWv1NyPJsMeK0HRi_DanH2+Z_4metoNG=txA@mail.gmail.com' \
--to=ard.biesheuvel@linaro.org \
--cc=dhowells@redhat.com \
--cc=hpa@zytor.com \
--cc=jlee@suse.com \
--cc=joeyli.kernel@gmail.com \
--cc=keescook@chromium.org \
--cc=keyrings@vger.kernel.org \
--cc=linux-efi@vger.kernel.org \
--cc=linux-integrity@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=oneukum@suse.com \
--cc=pavel@ucw.cz \
--cc=rafael.j.wysocki@intel.com \
--cc=tglx@linutronix.de \
--cc=x86@kernel.org \
--cc=yu.c.chen@intel.com \
--cc=yu.chen.surf@gmail.com \
--cc=zohar@linux.vnet.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).