Re: Plan of action for Secure Boot support

2014-08-20 Thread Paul R. Tagliamonte
Perhaps we should find time to hack at DebConf

 -T

On Tue, Aug 19, 2014 at 5:16 PM, Steve McIntyre  wrote:
> On Tue, Aug 19, 2014 at 01:38:44PM -0700, Ben Hutchings wrote:
>>
>>So far as I know, no progress has been made on the above steps or any
>>alternate approach.
>
> Ditto, I've not seen (or done) anything about this.
>
> --
> Steve McIntyre, Cambridge, UK.st...@einval.com
>   Mature Sporty Personal
>   More Innovation More Adult
>   A Man in Dandism
>   Powered Midship Specialty
>



-- 
:wq


-- 
To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
Archive: 
https://lists.debian.org/CAO6P2QQQaRyyJ=35Vm=Ux+xst=ln56t5uv0kx8oj3dkwyr6...@mail.gmail.com



Re: Plan of action for Secure Boot support

2014-08-19 Thread Steve McIntyre
On Tue, Aug 19, 2014 at 01:38:44PM -0700, Ben Hutchings wrote:
>
>So far as I know, no progress has been made on the above steps or any
>alternate approach.

Ditto, I've not seen (or done) anything about this.

-- 
Steve McIntyre, Cambridge, UK.st...@einval.com
  Mature Sporty Personal
  More Innovation More Adult
  A Man in Dandism
  Powered Midship Specialty


-- 
To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
Archive: https://lists.debian.org/20140819211641.gi7...@einval.com



Re: Plan of action for Secure Boot support

2014-08-19 Thread Ben Hutchings
On Thu, 2014-08-14 at 23:38 +0200, Cyril Brulebois wrote:
[...]
> > 1. Colin Watson will prepare dak changes to support upload and
> > subsequent signing of EFI executables.  (This is an embedded, not
> > detached, signature.)
> > 
> > 2. Steve Langasek will prepare and upload a package of the 'shim' EFI
> > boot loader.  This will embed our own set of public keys
> > (corresponding to those used by dak) and can load any other EFI
> > executable signed by one of them.  Later, there will be a shim-signed
> > package containing the same executable with a Microsoft signature.
> > (This costs money and takes several days, but shim should require only
> > very infrequent changes.)
> > 
> > 3. Colin Watson will update the GRUB package to build a to-be-signed
> > monolithic EFI executable separate from the package.  Then he will add
> > a grub-signed package that includes the Debian-signed executable from
> > the archive.  This executable would be suitable for use on both
> > removable media and the installed system.
> > 
> > 4. The kernel team may also need to upload kernel images for signing
> > and add linux-image-signed packages with the Debian-signed kernel
> > images.  This is because some quirks in the kernel should be run
> > before calling ExitBootServices().
> 
> could you please tell us whether anything changed during the past year?
> Is there any chance we could think of having SB in jessie, or should we
> consider it an unreasonable goal for this release and concentrate on
> other things?

So far as I know, no progress has been made on the above steps or any
alternate approach.

Ben.

-- 
Ben Hutchings
Anthony's Law of Force: Don't force it, get a larger hammer.


signature.asc
Description: This is a digitally signed message part


Re: Plan of action for Secure Boot support

2014-08-14 Thread Cyril Brulebois
Hi Ben,

Ben Hutchings  (2013-08-13):
> Colin Watson and Stefano Rivera talked about how Ubuntu had implemented
> Secure Boot and what they believed were the requirements.
> 
> Apparently, the Secure Boot spec requires each stage of the boot code
> to validate signatures only until ExitBootServices() is called.  (At
> this point the firmware makes some parts of its non-volatile
> configuration inaccessible.)
> 
> While some users would probably like to be able to 'lock down' the
> kernel, requiring signed modules and disabling other kernel features
> that allow code injection, this does not seem to be a requirement for
> booting on systems that implement Windows 8 logo requirements in the
> usual way, i.e. that require a Microsoft-signed first stage boot
> loader.
> 
> There seemed to be a consensus that we could use an implementation
> quite similar to Ubuntu's.  Some may be concerned that use of a
> Microsoft signing key results in a non-free binary, but so long as the
> target machines (amd64 architecture) generally allow installation of
> alternate public keys this is not so different from the way that APT
> on a Debian system requires Debian-signed Release files by default.
> 
> So the plan seems to be:
> 
> 1. Colin Watson will prepare dak changes to support upload and
> subsequent signing of EFI executables.  (This is an embedded, not
> detached, signature.)
> 
> 2. Steve Langasek will prepare and upload a package of the 'shim' EFI
> boot loader.  This will embed our own set of public keys
> (corresponding to those used by dak) and can load any other EFI
> executable signed by one of them.  Later, there will be a shim-signed
> package containing the same executable with a Microsoft signature.
> (This costs money and takes several days, but shim should require only
> very infrequent changes.)
> 
> 3. Colin Watson will update the GRUB package to build a to-be-signed
> monolithic EFI executable separate from the package.  Then he will add
> a grub-signed package that includes the Debian-signed executable from
> the archive.  This executable would be suitable for use on both
> removable media and the installed system.
> 
> 4. The kernel team may also need to upload kernel images for signing
> and add linux-image-signed packages with the Debian-signed kernel
> images.  This is because some quirks in the kernel should be run
> before calling ExitBootServices().

could you please tell us whether anything changed during the past year?
Is there any chance we could think of having SB in jessie, or should we
consider it an unreasonable goal for this release and concentrate on
other things?

Mraw,
KiBi.


signature.asc
Description: Digital signature


Re: Plan of action for Secure Boot support

2014-05-25 Thread Florian Weimer
* Colin Watson:

> On Wed, Jan 08, 2014 at 08:31:11AM +0100, Florian Weimer wrote:
>> Furthermore, we need to store the keys for all EV certificates (both
>> the certificate used for submission, and the certificate embedded in
>> the shim) in devices that meet at least FIPS 140 Level 2.  Such
>> devices that are affordable, support secure, remote operation, and are
>> compatible with free software environments are difficult to find.
>> (But perhaps we can find a DD who agrees to keep the keys in his or
>> her home and manually signs our kernels, using Windows if necessary.)
>
> We (Canonical) have been trying to get this requirement made a bit more
> sane; we keep our SB root certificate split up among a number of
> shareholders using gfshare, which we believe should be functionally
> adequate for this.  Steve Langasek may know where this sits.

Have you had any success in this endeavor?


-- 
To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
Archive: https://lists.debian.org/87siny87ss@mid.deneb.enyo.de



Re: Plan of action for Secure Boot support

2014-01-08 Thread Florian Weimer
* Ben Hutchings:

>> The Terms & Conditions of existing EV code-signing CAs do not permit a
>> code-signing end-entity certificate to be used for signing another
>> certificate, so we'd directly have to embed the end-entity certificate
>> used to sign GRUB and the kernel into the shim—or we'd have to ship
>> the EV root CA, but that would extend complete trust to that CA.  If
>> we embed the end-entity certificate, we need to submit a new shim to
>> Microsoft for signing each time the certificate changes (say, because
>> the previous certificate expired after a year).
>
> Presumably actual code signatures never expire (or rather, expiry should
> not be checked) - as that would mean mandatory upgrades just to keep a
> machine bootable.

It's not a technical issue.  The CA/subscriber agreement doesn't
permit making new signatures after the certificate has expired.

>> With KVM, we can boot another operating system after executing
>> unauthenticated (userspace) code, so the new policy seems to force us
>> to disable KVM per item 5 (b) (or extended Secure Boot to qemu-kvm,
>> which is practically impossible at present because we do not have a
>> signed userspace).
>
> MS can go and stick their collective head in a blender if they expect us
> to do that.

The usualy argument against disabling KVM is that in order to get KVM
support, you need to activate it in the BIOS.  I haven't seen enough
machines to tell if this is actually true.

>> There is also a significant technical limitation: The current
>> shim/grub/kernel combination is totally untested as far as revocation
>> is concerned.  Fedora does not blacklist kernels with known
>> root-to-ring-0 escalation vulnerabilities.
>
> Well, that would be almost all of them, right?

Yes, it would apply to all but the latest kernel.

>> This means that you can
>> just downgrade the kernel to a known-vulnerable version and lose all
>> protections allegedly provided by Secure Boot (as far as the Linux
>> side is concerned).  On the other hand, no one really wants to fix
>> this because it would mean that users cannot downgrade kernels anymore
>> to deal with regressions.
>
> I expect MS doesn't blacklist their old kernel versions, for exactly the
> same reason.  Or do they?

It's not clear to me what Microsoft's objectives are.  Kernel signing
might not be required if they only want to save the cost of read-only
recovery media.  Their installation/recovery kernel does not appear to
be equivalent to the real thing, and vulnerabilities in it would not
matter as long as the signature checking works (for both kernel and
userspace code) and no code with useful vulnerabilities runs before
user interaction.

There's an expectation nowadays that Secure Boot can protect against
careful implants, which is clearly not true on Linux because you could
just target the initrd or any of the early boot scripts, without the
need for any exploits.  Even on Windows, Secure Boot is unlikely to be
able to help against unknown implants (or malware injected into the
boot process), but it's likely that it enables a reliable recovery
path once malware is detectable (and before the malware can, in turn,
detect the detection—it's just like Core War).

Part of the problem is that Microsoft is extremely tight-lipped about
their objectives and policies.  As a result, we pick up isolated
aspects and assume they reflect an overarching grand plan.  But so
far, things we once took for granted (like the $99 fee to get started)
turned out to be just temporary.

>> In short, I think it is very hard for us to comply with the new
>> Microsoft guidelines.  It is also politically problematic because once
>> we comply, Microsoft could try to claim that mandatory Secure Boot is
>> not locking out anyone (because it's not just Fedora anymore).
>
> Because there are no Linux distributions made by anyone but RH, SUSE,
> Canonical and Debian?

I might not be up to date on this, but I think only Fedora promoted
Secure Boot, and likely did more for the broad acceptance of the
concept as such than Microsoft.  It's also pretty clear that
Microsoft's recent policy changes are partly influenced by Fedora's
Secure Boot capabilities.

Other distributions either didn't try very hard (no signature checking
after ExitBootServices, which is a valid interpretation of the UEFI
Secure Boot specification, but not compatible with Microsoft Secure
Boot) or explicitly decided against joining the Microsoft Secure Boot
ecosystem.


--
To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
Archive: http://lists.debian.org/87bnzm440t@mid.deneb.enyo.de



Re: Plan of action for Secure Boot support

2014-01-08 Thread Ben Hutchings
On Wed, 2014-01-08 at 08:31 +0100, Florian Weimer wrote:
> * Ben Hutchings:
> 
> > However, there is now a blog post from Microsoft that supports what
> > Matthew Garrett has been saying for a while - they may revoke the
> > signature on a boot loader if signature verification is not extended to
> > the kernel, including any mechanism to chain-load another kernel:
> >
> > http://blogs.msdn.com/b/windows_hardware_certification/archive/2013/12/03/microsoft-uefi-ca-signing-policy-updates.aspx
> > (specifically point 5(b))
> >
> > This implies that when Secure Boot is enabled, only signed kernels and
> > modules can be loaded and other features that allow code injection such
> > as kexec, hibernation and /dev/mem must be disabled.
> 
> We also need to use an EV certificate in the shim—not just for
> submission to Microsoft, but also for the certificate that signs GRUB
> and the kernel (item 6 (a)).
> 
> The Terms & Conditions of existing EV code-signing CAs do not permit a
> code-signing end-entity certificate to be used for signing another
> certificate, so we'd directly have to embed the end-entity certificate
> used to sign GRUB and the kernel into the shim—or we'd have to ship
> the EV root CA, but that would extend complete trust to that CA.  If
> we embed the end-entity certificate, we need to submit a new shim to
> Microsoft for signing each time the certificate changes (say, because
> the previous certificate expired after a year).

Presumably actual code signatures never expire (or rather, expiry should
not be checked) - as that would mean mandatory upgrades just to keep a
machine bootable.  CA certificates just need to be updated so they are
valid at the point in time they make a signature, right?

> Furthermore, we need to store the keys for all EV certificates (both
> the certificate used for submission, and the certificate embedded in
> the shim) in devices that meet at least FIPS 140 Level 2.  Such
> devices that are affordable, support secure, remote operation, and are
> compatible with free software environments are difficult to find.
> (But perhaps we can find a DD who agrees to keep the keys in his or
> her home and manually signs our kernels, using Windows if necessary.)
> 
> I'm not sure if we can sign sid kernels because of the requirement to
> sign production quality code only.

testing/unstable is a rolling beta test for the next stable release; I
would have thought that was still 'production' in MS's terms.

experimental maybe shouldn't be signed.

> With KVM, we can boot another operating system after executing
> unauthenticated (userspace) code, so the new policy seems to force us
> to disable KVM per item 5 (b) (or extended Secure Boot to qemu-kvm,
> which is practically impossible at present because we do not have a
> signed userspace).

MS can go and stick their collective head in a blender if they expect us
to do that.

[...]
> There is also a significant technical limitation: The current
> shim/grub/kernel combination is totally untested as far as revocation
> is concerned.  Fedora does not blacklist kernels with known
> root-to-ring-0 escalation vulnerabilities.

Well, that would be almost all of them, right?

> This means that you can
> just downgrade the kernel to a known-vulnerable version and lose all
> protections allegedly provided by Secure Boot (as far as the Linux
> side is concerned).  On the other hand, no one really wants to fix
> this because it would mean that users cannot downgrade kernels anymore
> to deal with regressions.

I expect MS doesn't blacklist their old kernel versions, for exactly the
same reason.  Or do they?

> In short, I think it is very hard for us to comply with the new
> Microsoft guidelines.  It is also politically problematic because once
> we comply, Microsoft could try to claim that mandatory Secure Boot is
> not locking out anyone (because it's not just Fedora anymore).

Because there are no Linux distributions made by anyone but RH, SUSE,
Canonical and Debian?

> We could still do our own thing under a root we control, but then we
> have to decide if we want to cross-certify everyone else.
> 
> We should probably continue the discussion on debian-project because
> it's not just about the kernel or technical issues.

Right.

Ben.

-- 
Ben Hutchings
Any smoothly functioning technology is indistinguishable from a rigged demo.


signature.asc
Description: This is a digitally signed message part


Re: Plan of action for Secure Boot support

2014-01-08 Thread Colin Watson
On Wed, Jan 08, 2014 at 08:31:11AM +0100, Florian Weimer wrote:
> Furthermore, we need to store the keys for all EV certificates (both
> the certificate used for submission, and the certificate embedded in
> the shim) in devices that meet at least FIPS 140 Level 2.  Such
> devices that are affordable, support secure, remote operation, and are
> compatible with free software environments are difficult to find.
> (But perhaps we can find a DD who agrees to keep the keys in his or
> her home and manually signs our kernels, using Windows if necessary.)

We (Canonical) have been trying to get this requirement made a bit more
sane; we keep our SB root certificate split up among a number of
shareholders using gfshare, which we believe should be functionally
adequate for this.  Steve Langasek may know where this sits.

> I wonder why Microsoft no longer wants to sign GPLv3 code (such as
> GRUB 2).  It could be due to plans to make Secure Boot mandatory
> eventually.  Right now, it is possible to comply with the GPLv3
> license requirements because users can switch off Secure Boot, either
> at the BIOS level or through the MokManager loophole.  This does not
> affect us because we rarely ship hardware with Debian pre-installed,
> and if we do, we can make use of the general GPLv3 opt-out clause.
> But it would affect some of our users.

Not that I'm very impressed with Microsoft's reasoning here, but in
practice we wouldn't want to get GRUB signed by Microsoft anyway; their
signing process is far too cumbersome for anything but a loader that we
try not to change very often.  Their guidelines permit chaining to GPLv3
code via shim, so this part of it should not be a problem.

-- 
Colin Watson   [cjwat...@debian.org]


-- 
To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
Archive: http://lists.debian.org/2014010830.ga20...@riva.ucam.org



Re: Plan of action for Secure Boot support

2014-01-07 Thread Florian Weimer
* Ben Hutchings:

> However, there is now a blog post from Microsoft that supports what
> Matthew Garrett has been saying for a while - they may revoke the
> signature on a boot loader if signature verification is not extended to
> the kernel, including any mechanism to chain-load another kernel:
>
> http://blogs.msdn.com/b/windows_hardware_certification/archive/2013/12/03/microsoft-uefi-ca-signing-policy-updates.aspx
> (specifically point 5(b))
>
> This implies that when Secure Boot is enabled, only signed kernels and
> modules can be loaded and other features that allow code injection such
> as kexec, hibernation and /dev/mem must be disabled.

We also need to use an EV certificate in the shim—not just for
submission to Microsoft, but also for the certificate that signs GRUB
and the kernel (item 6 (a)).

The Terms & Conditions of existing EV code-signing CAs do not permit a
code-signing end-entity certificate to be used for signing another
certificate, so we'd directly have to embed the end-entity certificate
used to sign GRUB and the kernel into the shim—or we'd have to ship
the EV root CA, but that would extend complete trust to that CA.  If
we embed the end-entity certificate, we need to submit a new shim to
Microsoft for signing each time the certificate changes (say, because
the previous certificate expired after a year).

Furthermore, we need to store the keys for all EV certificates (both
the certificate used for submission, and the certificate embedded in
the shim) in devices that meet at least FIPS 140 Level 2.  Such
devices that are affordable, support secure, remote operation, and are
compatible with free software environments are difficult to find.
(But perhaps we can find a DD who agrees to keep the keys in his or
her home and manually signs our kernels, using Windows if necessary.)

I'm not sure if we can sign sid kernels because of the requirement to
sign production quality code only.

With KVM, we can boot another operating system after executing
unauthenticated (userspace) code, so the new policy seems to force us
to disable KVM per item 5 (b) (or extended Secure Boot to qemu-kvm,
which is practically impossible at present because we do not have a
signed userspace).  Obviously, one can still start a virtualized
environment without hardware support, and I don't know what this means
for compliance.

I wonder why Microsoft no longer wants to sign GPLv3 code (such as
GRUB 2).  It could be due to plans to make Secure Boot mandatory
eventually.  Right now, it is possible to comply with the GPLv3
license requirements because users can switch off Secure Boot, either
at the BIOS level or through the MokManager loophole.  This does not
affect us because we rarely ship hardware with Debian pre-installed,
and if we do, we can make use of the general GPLv3 opt-out clause.
But it would affect some of our users.

There is also a significant technical limitation: The current
shim/grub/kernel combination is totally untested as far as revocation
is concerned.  Fedora does not blacklist kernels with known
root-to-ring-0 escalation vulnerabilities.  This means that you can
just downgrade the kernel to a known-vulnerable version and lose all
protections allegedly provided by Secure Boot (as far as the Linux
side is concerned).  On the other hand, no one really wants to fix
this because it would mean that users cannot downgrade kernels anymore
to deal with regressions.

In short, I think it is very hard for us to comply with the new
Microsoft guidelines.  It is also politically problematic because once
we comply, Microsoft could try to claim that mandatory Secure Boot is
not locking out anyone (because it's not just Fedora anymore).

We could still do our own thing under a root we control, but then we
have to decide if we want to cross-certify everyone else.

We should probably continue the discussion on debian-project because
it's not just about the kernel or technical issues.


--
To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
Archive: http://lists.debian.org/878uurexq8@mid.deneb.enyo.de



Re: Plan of action for Secure Boot support

2013-12-09 Thread Ben Hutchings
On Tue, 2013-08-13 at 22:54 +0200, Ben Hutchings wrote:
[...]
> Apparently, the Secure Boot spec requires each stage of the boot code to
> validate signatures only until ExitBootServices() is called.  (At this
> point the firmware makes some parts of its non-volatile configuration
> inaccessible.)
[...]

However, there is now a blog post from Microsoft that supports what
Matthew Garrett has been saying for a while - they may revoke the
signature on a boot loader if signature verification is not extended to
the kernel, including any mechanism to chain-load another kernel:

http://blogs.msdn.com/b/windows_hardware_certification/archive/2013/12/03/microsoft-uefi-ca-signing-policy-updates.aspx
(specifically point 5(b))

This implies that when Secure Boot is enabled, only signed kernels and
modules can be loaded and other features that allow code injection such
as kexec, hibernation and /dev/mem must be disabled.

Or we cross our fingers and hope no-one uses Debian's shim in a Windows
boot kit.

(There is work on a new kexec interface which could include signature
verification.  I think there is a theoretical solution for hibernation
but I don't think it has been implemented.)

Ben.

-- 
Ben Hutchings
One of the nice things about standards is that there are so many of them.


signature.asc
Description: This is a digitally signed message part


Re: Plan of action for Secure Boot support

2013-08-14 Thread Bastian Blank
On Wed, Aug 14, 2013 at 12:30:55AM +0200, Ben Hutchings wrote:
> Editing of binary packages is icky, so that's not part of the plan.
> Instead, after dak signs an executable, the package maintainer downloads
> and copies those into a separate 'source' package, which has a trivial
> debian/rules.  (And of course will generate an appropriate 'Built-Using'
> header.)

This will most likely go via by-hand. So a script on the dak side is
needed anyway.

Why not do the dummy source package stuff in this script and let dak do
all the work semi-automatically? It needs a prepared binary tree in a
tar, a list of files to be signed and a DEBIAN dir.

Bastian

-- 
Landru! Guide us!
-- A Beta 3-oid, "The Return of the Archons", stardate 3157.4


-- 
To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
Archive: http://lists.debian.org/20130814094925.ga16...@mail.waldi.eu.org



Re: Plan of action for Secure Boot support

2013-08-13 Thread Ben Hutchings
On Tue, 2013-08-13 at 23:38 +0200, Cyril Brulebois wrote:
[...] 
> > 4. The kernel team may also need to upload kernel images for signing and
> > add linux-image-signed packages with the Debian-signed kernel images.
> > This is because some quirks in the kernel should be run before calling
> > ExitBootServices().
> 
> (Sorry, I'm new to all this) do you mean (1) the regular linux image
> packages are getting a signature added, and we're using those like we do
> today, or (2) that we'll have additional linux image packages with the
> signatures to be used instead of the usual linux image packages when a
> Secure Boot environment is detected? (or (3) something else…)
[...]

Signing of EFI executables (aside from MS signature on shim) would be
done by dak and would require manual intervention from the FTP team.

Editing of binary packages is icky, so that's not part of the plan.
Instead, after dak signs an executable, the package maintainer downloads
and copies those into a separate 'source' package, which has a trivial
debian/rules.  (And of course will generate an appropriate 'Built-Using'
header.)

I suppose GRUB's Linux configuration generator will also need to prefer
a signed vmlinuz (whatever name it gets) to the unsigned version.

Ben.

-- 
Ben Hutchings
Any smoothly functioning technology is indistinguishable from a rigged demo.


signature.asc
Description: This is a digitally signed message part


Re: Plan of action for Secure Boot support

2013-08-13 Thread Joey Hess
Cyril Brulebois wrote:
> (Sorry, I'm new to all this) do you mean (1) the regular linux image
> packages are getting a signature added, and we're using those like we do
> today, or (2) that we'll have additional linux image packages with the
> signatures to be used instead of the usual linux image packages when a
> Secure Boot environment is detected? (or (3) something else…)

The secure boot shim is a small bootloader. It's the only part that
absolutely needs to be signed by MS, AIUI. It was designed to facilitate
distributions in our position. Signed versions are also already
available, produced by DD Matthew Garret, though not as Debian packages
(perhaps he could be convinced to maintain it?)

http://mjg59.dreamwidth.org/20303.html
http://www.codon.org.uk/~mjg59/shim-signed/

(Assuming the plan is to use Matthew's shim and not the other one
created by IIRC, the Linux Foundation.)

-- 
see shy jo


signature.asc
Description: Digital signature


Re: Plan of action for Secure Boot support

2013-08-13 Thread Cyril Brulebois
Hi,

many thanks for the summary.

Ben Hutchings  (2013-08-13):
> Colin Watson and Stefano Rivera talked about how Ubuntu had implemented
> Secure Boot and what they believed were the requirements.
> 
> Apparently, the Secure Boot spec requires each stage of the boot code to
> validate signatures only until ExitBootServices() is called.  (At this
> point the firmware makes some parts of its non-volatile configuration
> inaccessible.)
> 
> While some users would probably like to be able to 'lock down' the
> kernel, requiring signed modules and disabling other kernel features
> that allow code injection, this does not seem to be a requirement for
> booting on systems that implement Windows 8 logo requirements in the
> usual way, i.e. that require a Microsoft-signed first stage boot loader.
> 
> There seemed to be a consensus that we could use an implementation quite
> similar to Ubuntu's.  Some may be concerned that use of a Microsoft
> signing key results in a non-free binary, but so long as the target
> machines (amd64 architecture) generally allow installation of alternate
> public keys this is not so different from the way that APT on a Debian
> system requires Debian-signed Release files by default.
> 
> So the plan seems to be:
> 
> 1. Colin Watson will prepare dak changes to support upload and subsequent
> signing of EFI executables.  (This is an embedded, not detached, signature.)
> 
> 2. Steve Langasek will prepare and upload a package of the 'shim' EFI
> boot loader.  This will embed our own set of public keys (corresponding
> to those used by dak) and can load any other EFI executable signed by
> one of them.  Later, there will be a shim-signed package containing the
> same executable with a Microsoft signature.  (This costs money and takes
> several days, but shim should require only very infrequent changes.)
> 
> 3. Colin Watson will update the GRUB package to build a to-be-signed
> monolithic EFI executable separate from the package.  Then he will add a
> grub-signed package that includes the Debian-signed executable from the
> archive.  This executable would be suitable for use on both removable
> media and the installed system.
> 
> 4. The kernel team may also need to upload kernel images for signing and
> add linux-image-signed packages with the Debian-signed kernel images.
> This is because some quirks in the kernel should be run before calling
> ExitBootServices().

(Sorry, I'm new to all this) do you mean (1) the regular linux image
packages are getting a signature added, and we're using those like we do
today, or (2) that we'll have additional linux image packages with the
signatures to be used instead of the usual linux image packages when a
Secure Boot environment is detected? (or (3) something else…)

[As a side yet relevant note: I think there's a general agreement that
we aren't going to target putting as many things as possible on a
regular CD like we used to do, so a few grub/bootloader things are
probably OK; having duplicate linux image packages wouldn't look too
nice though.]

Mraw,
KiBi.


-- 
To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
Archive: http://lists.debian.org/20130813213857.ga25...@mraw.org



Re: Plan of action for Secure Boot support

2013-08-13 Thread Ben Hutchings
On Tue, 2013-08-13 at 22:54 +0200, Ben Hutchings wrote:
> Colin Watson and Stefano Rivera talked about how Ubuntu had implemented
> Secure Boot and what they believed were the requirements.
[...]

Sorry, I'm having name confusion here.  Who do I really mean?

Ben.

-- 
Ben Hutchings
Experience is what causes a person to make new mistakes instead of old ones.


signature.asc
Description: This is a digitally signed message part