From: Petko Manolov <firstname.lastname@example.org>
To: David Howells <email@example.com>
Cc: firstname.lastname@example.org, email@example.com,
Mimi Zohar <firstname.lastname@example.org>
Subject: Re: [PATCH 4/9] KEYS: Allow unrestricted boot-time addition of keys to secondary keyring
Date: Thu, 17 Nov 2016 12:22:05 +0200 [thread overview]
Message-ID: <20161117102205.hoypgpq5hfw6z2w7@p310> (raw)
On 16-11-17 09:56:00, David Howells wrote:
> Petko Manolov <email@example.com> wrote:
> > On 16-11-16 18:11:13, David Howells wrote:
> > > Allow keys to be added to the system secondary certificates keyring during
> > > kernel initialisation in an unrestricted fashion. Such keys are
> > > implicitly trusted and don't have their trust chains checked on link.
> > Well, I for one do not explicitly trust these keys. I may even want to
> > completely remove or replace them.
> Fine be me. However, if you remove them all I would guess that you cannot
> perform a secure boot.
Maybe not on PC, but there's plenty of other architectures out there. What if i
replace all UEFI keys with my own?
> Note that it's to be expected that the keys being loaded from the UEFI
> database cannot have their signatures checked - which is why they would have
> to be implicitly trusted. For the same reason, the kernel does not check the
> signatures on the keys compiled into the kernel image.
I build all kernels that matter to me and i _do_ trust myself. Unfortunately i
can't say the same for any corporation out there.
Trusting a key because your vendor shipped the HW with it so that you have no
way to verify the signature is pretty weak argument IMHO.
However, I am also well aware that most people just don't care. :)
> > > This allows keys in the UEFI database to be added in secure boot mode for
> > > the purposes of module signing.
> > The key import should not be automatic, it should be optional.
> You can argue this either way. There's a config option to allow you to turn
> this on or off. Arguably, this should be split in two: one for the whitelist
> (db, MokListRT) and one for the blacklist (dbx).
I did not see the config option. There is one?
Right now i can't decide whether whitelist should go along with blacklist or
there should be separate options. I guess for whoever goes down this path it
would make sense to use either both or none of them.
> Further, possibly I should add an option that allows this to be restricted to
> secure boot mode only.
Please do. It doesn't make much sense otherwise.
> > Same applies to the validation process.
> Depends what you mean by "the validation process"? The use of secure boot at
> all? The checking of signatures on keys? Module signing?
Nevermind. The keys signature can't be verified in the classic UEFI case.
next prev parent reply other threads:[~2016-11-17 10:22 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-16 18:10 [PATCH 0/9] KEYS: Blacklisting & UEFI database load David Howells
2016-11-16 18:10 ` [PATCH 1/9] KEYS: Add a system blacklist keyring David Howells
2016-11-16 18:10 ` [PATCH 2/9] X.509: Allow X.509 certs to be blacklisted David Howells
2016-11-16 18:11 ` [PATCH 3/9] PKCS#7: Handle blacklisted certificates David Howells
2016-11-16 18:11 ` [PATCH 4/9] KEYS: Allow unrestricted boot-time addition of keys to secondary keyring David Howells
2016-11-17 6:41 ` Petko Manolov
2016-11-17 9:56 ` David Howells
2016-11-17 10:22 ` Petko Manolov [this message]
2016-11-17 11:18 ` David Howells
2016-11-21 14:04 ` Mimi Zohar
2016-11-21 15:17 ` David Howells
2016-11-21 16:24 ` Mimi Zohar
2016-11-16 18:11 ` [PATCH 5/9] efi: Add SHIM and image security database GUID definitions David Howells
2016-11-21 16:07 ` Ard Biesheuvel
2016-11-16 18:11 ` [PATCH 6/9] efi: Add EFI signature data types David Howells
2016-11-16 23:43 ` Mat Martineau
2016-11-17 9:44 ` David Howells
2016-11-21 16:08 ` Ard Biesheuvel
2016-11-16 18:11 ` [PATCH 7/9] efi: Add an EFI signature blob parser David Howells
2016-11-16 18:11 ` [PATCH 8/9] MODSIGN: Import certificates from UEFI Secure Boot David Howells
2016-11-21 16:16 ` Ard Biesheuvel
2016-11-21 16:25 ` Josh Boyer
2016-11-24 19:22 ` James Bottomley
2016-11-24 19:17 ` James Bottomley
2016-12-02 18:57 ` James Bottomley
2016-12-02 20:18 ` Mimi Zohar
2016-11-16 18:11 ` [PATCH 9/9] MODSIGN: Allow the "db" UEFI variable to be suppressed David Howells
2016-11-21 16:18 ` Ard Biesheuvel
2016-11-21 16:26 ` Josh Boyer
2016-11-21 16:42 ` Ard Biesheuvel
2016-11-21 19:05 ` Peter Jones
2016-11-21 19:06 ` Ard Biesheuvel
2016-11-21 19:18 ` Peter Jones
2016-11-21 19:33 ` Ard Biesheuvel
2018-03-06 14:05 ` [PATCH 0/9] KEYS: Blacklisting & UEFI database load Jiri Slaby
2018-03-07 13:18 ` Mimi Zohar
2018-03-07 15:28 ` James Bottomley
2018-03-11 3:20 ` joeyli
2018-03-19 14:12 ` Mimi Zohar
2018-03-27 11:08 ` joeyli
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