| Message ID | 20220126025834.255493-1-eric.snowberg@oracle.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Enroll kernel keys thru MOK | expand |
On Tue, Jan 25, 2022 at 09:58:26PM -0500, Eric Snowberg wrote: > Back in 2013 Linus requested a feature to allow end-users to have the > ability "to add their own keys and sign modules they trust". This was > his *second* order outlined here [1]. There have been many attempts > over the years to solve this problem, all have been rejected. Many > of the failed attempts loaded all preboot firmware keys into the kernel, > including the Secure Boot keys. Many distributions carry one of these > rejected attempts [2], [3], [4]. This series tries to solve this problem > with a solution that takes into account all the problems brought up in > the previous attempts. > > On UEFI based systems, this series introduces a new Linux kernel keyring > containing the Machine Owner Keys (MOK) called machine. It also defines > a new MOK variable in shim. This variable allows the end-user to decide > if they want to load MOK keys into the machine keyring. > > By default, nothing changes; MOK keys are not loaded into the machine > keyring. They are only loaded after the end-user makes the decision > themselves. The end-user would set this through mokutil using a new > --trust-mok option [5]. This would work similar to how the kernel uses > MOK variables to enable/disable signature validation as well as use/ignore > the db. Any kernel operation that uses either the builtin or secondary > trusted keys as a trust source shall also reference the new machine > keyring as a trust source. > > Secure Boot keys will never be loaded into the machine keyring. They > will always be loaded into the platform keyring. If an end-user wanted > to load one, they would need to enroll it into the MOK. > > Unlike previous versions of this patch set, IMA support has been removed > to simplify the series. After acceptance, a follow-on series will add IMA > support. > > Steps required by the end user: > > Sign kernel module with user created key: > $ /usr/src/kernels/$(uname -r)/scripts/sign-file sha512 \ > machine_signing_key.priv machine_signing_key.x509 my_module.ko > > Import the key into the MOK > $ mokutil --import machine_signing_key.x509 > > Setup the kernel to load MOK keys into the .machine keyring > $ mokutil --trust-mok > > Then reboot, the MokManager will load and ask if you want to trust the > MOK key and enroll the MOK into the MOKList. Afterwards the signed kernel > module will load. > > I have included a link to the mokutil [5] changes I have made to support > this new functionality. The shim changes have now been accepted > upstream [6]. > > Upstream shim is located here [7], the build instructions are here [8]. > TLDR: > > $ git clone --recurse-submodules https://github.com/rhboot/shim > $ cd shim > $ make > > After building shim, move shimx64.efi and mmx64.efi to the vendor or > distribution specific directory on your EFI System Partition (assuming > you are building on x86). The instructions above are the minimal > steps needed to build shim to test this feature. It is assumed > Secure Boot shall not be enabled for this testing. To do testing > with Secure Boot enabled, all steps in the build instructions [8] > must be followed. > > Instructions for building mokutil (including the new changes): > > $ git clone -b mokvars-v3 https://github.com/esnowberg/mokutil.git > $ cd mokutil/ > $ ./autogen.sh > $ make > > [1] https://marc.info/?l=linux-kernel&m=136185386310140&w=2 > [2] https://lore.kernel.org/lkml/1479737095.2487.34.camel@linux.vnet.ibm.com/ > [3] https://lore.kernel.org/lkml/1556221605.24945.3.camel@HansenPartnership.com/ > [4] https://lore.kernel.org/linux-integrity/1e41f22b1f11784f1e943f32bf62034d4e054cdb.camel@HansenPartnership.com/ > [5] https://github.com/esnowberg/mokutil/tree/mokvars-v3 > [6] https://github.com/rhboot/shim/commit/4e513405b4f1641710115780d19dcec130c5208f > [7] https://github.com/rhboot/shim > [8] https://github.com/rhboot/shim/blob/main/BUILDING > > Eric Snowberg (8): > integrity: Fix warning about missing prototypes > integrity: Introduce a Linux keyring called machine > integrity: add new keyring handler for mok keys > KEYS: store reference to machine keyring > KEYS: Introduce link restriction for machine keys > efi/mokvar: move up init order > integrity: Trust MOK keys if MokListTrustedRT found > integrity: Only use machine keyring when uefi_check_trust_mok_keys is > true > > certs/system_keyring.c | 44 ++++++++++- > drivers/firmware/efi/mokvar-table.c | 2 +- > include/keys/system_keyring.h | 14 ++++ > security/integrity/Kconfig | 13 ++++ > security/integrity/Makefile | 1 + > security/integrity/digsig.c | 15 +++- > security/integrity/integrity.h | 17 +++- > .../platform_certs/keyring_handler.c | 18 ++++- > .../platform_certs/keyring_handler.h | 5 ++ > security/integrity/platform_certs/load_uefi.c | 4 +- > .../platform_certs/machine_keyring.c | 77 +++++++++++++++++++ > 11 files changed, 202 insertions(+), 8 deletions(-) > create mode 100644 security/integrity/platform_certs/machine_keyring.c > > > base-commit: e783362eb54cd99b2cac8b3a9aeac942e6f6ac07 > -- > 2.18.4 > Thank you. I'll pick these soon. Is there any objections? /Jarkko
On Wed, Jan 26, 2022 at 03:43:07PM +0200, Jarkko Sakkinen wrote: > On Tue, Jan 25, 2022 at 09:58:26PM -0500, Eric Snowberg wrote: > > Back in 2013 Linus requested a feature to allow end-users to have the > > ability "to add their own keys and sign modules they trust". This was > > his *second* order outlined here [1]. There have been many attempts > > over the years to solve this problem, all have been rejected. Many > > of the failed attempts loaded all preboot firmware keys into the kernel, > > including the Secure Boot keys. Many distributions carry one of these > > rejected attempts [2], [3], [4]. This series tries to solve this problem > > with a solution that takes into account all the problems brought up in > > the previous attempts. > > > > On UEFI based systems, this series introduces a new Linux kernel keyring > > containing the Machine Owner Keys (MOK) called machine. It also defines > > a new MOK variable in shim. This variable allows the end-user to decide > > if they want to load MOK keys into the machine keyring. > > > > By default, nothing changes; MOK keys are not loaded into the machine > > keyring. They are only loaded after the end-user makes the decision > > themselves. The end-user would set this through mokutil using a new > > --trust-mok option [5]. This would work similar to how the kernel uses > > MOK variables to enable/disable signature validation as well as use/ignore > > the db. Any kernel operation that uses either the builtin or secondary > > trusted keys as a trust source shall also reference the new machine > > keyring as a trust source. > > > > Secure Boot keys will never be loaded into the machine keyring. They > > will always be loaded into the platform keyring. If an end-user wanted > > to load one, they would need to enroll it into the MOK. > > > > Unlike previous versions of this patch set, IMA support has been removed > > to simplify the series. After acceptance, a follow-on series will add IMA > > support. > > > > Steps required by the end user: > > > > Sign kernel module with user created key: > > $ /usr/src/kernels/$(uname -r)/scripts/sign-file sha512 \ > > machine_signing_key.priv machine_signing_key.x509 my_module.ko > > > > Import the key into the MOK > > $ mokutil --import machine_signing_key.x509 > > > > Setup the kernel to load MOK keys into the .machine keyring > > $ mokutil --trust-mok > > > > Then reboot, the MokManager will load and ask if you want to trust the > > MOK key and enroll the MOK into the MOKList. Afterwards the signed kernel > > module will load. > > > > I have included a link to the mokutil [5] changes I have made to support > > this new functionality. The shim changes have now been accepted > > upstream [6]. > > > > Upstream shim is located here [7], the build instructions are here [8]. > > TLDR: > > > > $ git clone --recurse-submodules https://github.com/rhboot/shim > > $ cd shim > > $ make > > > > After building shim, move shimx64.efi and mmx64.efi to the vendor or > > distribution specific directory on your EFI System Partition (assuming > > you are building on x86). The instructions above are the minimal > > steps needed to build shim to test this feature. It is assumed > > Secure Boot shall not be enabled for this testing. To do testing > > with Secure Boot enabled, all steps in the build instructions [8] > > must be followed. > > > > Instructions for building mokutil (including the new changes): > > > > $ git clone -b mokvars-v3 https://github.com/esnowberg/mokutil.git > > $ cd mokutil/ > > $ ./autogen.sh > > $ make > > > > [1] https://marc.info/?l=linux-kernel&m=136185386310140&w=2 > > [2] https://lore.kernel.org/lkml/1479737095.2487.34.camel@linux.vnet.ibm.com/ > > [3] https://lore.kernel.org/lkml/1556221605.24945.3.camel@HansenPartnership.com/ > > [4] https://lore.kernel.org/linux-integrity/1e41f22b1f11784f1e943f32bf62034d4e054cdb.camel@HansenPartnership.com/ > > [5] https://github.com/esnowberg/mokutil/tree/mokvars-v3 > > [6] https://github.com/rhboot/shim/commit/4e513405b4f1641710115780d19dcec130c5208f > > [7] https://github.com/rhboot/shim > > [8] https://github.com/rhboot/shim/blob/main/BUILDING > > > > Eric Snowberg (8): > > integrity: Fix warning about missing prototypes > > integrity: Introduce a Linux keyring called machine > > integrity: add new keyring handler for mok keys > > KEYS: store reference to machine keyring > > KEYS: Introduce link restriction for machine keys > > efi/mokvar: move up init order > > integrity: Trust MOK keys if MokListTrustedRT found > > integrity: Only use machine keyring when uefi_check_trust_mok_keys is > > true > > > > certs/system_keyring.c | 44 ++++++++++- > > drivers/firmware/efi/mokvar-table.c | 2 +- > > include/keys/system_keyring.h | 14 ++++ > > security/integrity/Kconfig | 13 ++++ > > security/integrity/Makefile | 1 + > > security/integrity/digsig.c | 15 +++- > > security/integrity/integrity.h | 17 +++- > > .../platform_certs/keyring_handler.c | 18 ++++- > > .../platform_certs/keyring_handler.h | 5 ++ > > security/integrity/platform_certs/load_uefi.c | 4 +- > > .../platform_certs/machine_keyring.c | 77 +++++++++++++++++++ > > 11 files changed, 202 insertions(+), 8 deletions(-) > > create mode 100644 security/integrity/platform_certs/machine_keyring.c > > > > > > base-commit: e783362eb54cd99b2cac8b3a9aeac942e6f6ac07 > > -- > > 2.18.4 > > > > Thank you. I'll pick these soon. Is there any objections? Mimi brought up that we need a MAINTAINERS update for this and also .platform. We have these: - KEYS/KEYRINGS - CERTIFICATE HANDLING I would put them under KEYRINGS for now and would not consider further subdivision for the moment. /Jarkko
Hi Jarkko, > > Thank you. I'll pick these soon. Is there any objections? No objections. > > Mimi brought up that we need a MAINTAINERS update for this and also > .platform. > > We have these: > > - KEYS/KEYRINGS > - CERTIFICATE HANDLING > > I would put them under KEYRINGS for now and would not consider further > subdivision for the moment. IMA has dependencies on the platform_certs/ and now on the new .machine keyring. Just adding "F: security/integrity/platform_certs/" to the KEYS/KEYRINGS record, ignores that dependency. The discussion wouldn't even be on the linux-integrity mailing list. Existing requirement: - The keys on the .platform keyring are limited to verifying the kexec image. New requirements based on Eric Snowbergs' patch set: - When IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY is enabled, the MOK keys will not be loaded directly onto the .machine keyring or indirectly onto the .secondary_trusted_keys keyring. - Only when a new IMA Kconfig explicitly allows the keys on the .machine keyrings, will the CA keys stored in MOK be loaded onto the .machine keyring. Unfortunately I don't think there is any choice, but to define a new MAINTAINERS entry. Perhaps something along the lines of: KEYS/KEYRINGS_INTEGRITY M: Jarkko Sakkinen <jarkko@kernel.org> M: Mimi Zohar <zohar@linux.ibm.com> L: keyrings@vger.kernel.org L: linux-integrity@vger.kernel.org F: security/integrity/platform_certs thanks, Mimi
On Wed, Jan 26, 2022 at 05:06:09PM -0500, Mimi Zohar wrote: > Hi Jarkko, > > > > Thank you. I'll pick these soon. Is there any objections? > > No objections. > > > > Mimi brought up that we need a MAINTAINERS update for this and also > > .platform. > > > > We have these: > > > > - KEYS/KEYRINGS > > - CERTIFICATE HANDLING > > > > I would put them under KEYRINGS for now and would not consider further > > subdivision for the moment. > > IMA has dependencies on the platform_certs/ and now on the new .machine > keyring. Just adding "F: security/integrity/platform_certs/" to the > KEYS/KEYRINGS record, ignores that dependency. The discussion wouldn't > even be on the linux-integrity mailing list. > > Existing requirement: > - The keys on the .platform keyring are limited to verifying the kexec > image. > > New requirements based on Eric Snowbergs' patch set: > - When IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY is enabled, > the MOK keys will not be loaded directly onto the .machine keyring or > indirectly onto the .secondary_trusted_keys keyring. > > - Only when a new IMA Kconfig explicitly allows the keys on the > .machine keyrings, will the CA keys stored in MOK be loaded onto the > .machine keyring. > > Unfortunately I don't think there is any choice, but to define a new > MAINTAINERS entry. Perhaps something along the lines of: > > KEYS/KEYRINGS_INTEGRITY > M: Jarkko Sakkinen <jarkko@kernel.org> > M: Mimi Zohar <zohar@linux.ibm.com> > L: keyrings@vger.kernel.org > L: linux-integrity@vger.kernel.org > F: security/integrity/platform_certs WFM. BTW, the patches are now in my tree: git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd.git I can add any tags requested. I'll mirror this at some point to linux-next. /Jarkko
(Updated subject line) On Tue, 2022-02-08 at 10:28 +0100, Jarkko Sakkinen wrote: > On Wed, Jan 26, 2022 at 05:06:09PM -0500, Mimi Zohar wrote: > > > Mimi brought up that we need a MAINTAINERS update for this and also > > > .platform. > > > > > > We have these: > > > > > > - KEYS/KEYRINGS > > > - CERTIFICATE HANDLING > > > > > > I would put them under KEYRINGS for now and would not consider further > > > subdivision for the moment. > > > > IMA has dependencies on the platform_certs/ and now on the new .machine > > keyring. Just adding "F: security/integrity/platform_certs/" to the > > KEYS/KEYRINGS record, ignores that dependency. The discussion wouldn't > > even be on the linux-integrity mailing list. > > > > Existing requirement: > > - The keys on the .platform keyring are limited to verifying the kexec > > image. > > > > New requirements based on Eric Snowbergs' patch set: > > - When IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY is enabled, > > the MOK keys will not be loaded directly onto the .machine keyring or > > indirectly onto the .secondary_trusted_keys keyring. > > > > - Only when a new IMA Kconfig explicitly allows the keys on the > > .machine keyrings, will the CA keys stored in MOK be loaded onto the > > .machine keyring. > > > > Unfortunately I don't think there is any choice, but to define a new > > MAINTAINERS entry. Perhaps something along the lines of: > > > > KEYS/KEYRINGS_INTEGRITY > > M: Jarkko Sakkinen <jarkko@kernel.org> > > M: Mimi Zohar <zohar@linux.ibm.com> > > L: keyrings@vger.kernel.org > > L: linux-integrity@vger.kernel.org > > F: security/integrity/platform_certs > > WFM. BTW, the patches are now in my tree: > > git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd.git > > I can add any tags requested. I'll mirror this at some point to linux-next. Thanks, Jarkko.
On Wed, Jan 26, 2022 at 05:06:09PM -0500, Mimi Zohar wrote: > Hi Jarkko, > > > > Thank you. I'll pick these soon. Is there any objections? > > No objections. > > > > Mimi brought up that we need a MAINTAINERS update for this and also > > .platform. > > > > We have these: > > > > - KEYS/KEYRINGS > > - CERTIFICATE HANDLING > > > > I would put them under KEYRINGS for now and would not consider further > > subdivision for the moment. > > IMA has dependencies on the platform_certs/ and now on the new .machine > keyring. Just adding "F: security/integrity/platform_certs/" to the > KEYS/KEYRINGS record, ignores that dependency. The discussion wouldn't > even be on the linux-integrity mailing list. > > Existing requirement: > - The keys on the .platform keyring are limited to verifying the kexec > image. > > New requirements based on Eric Snowbergs' patch set: > - When IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY is enabled, > the MOK keys will not be loaded directly onto the .machine keyring or > indirectly onto the .secondary_trusted_keys keyring. > > - Only when a new IMA Kconfig explicitly allows the keys on the > .machine keyrings, will the CA keys stored in MOK be loaded onto the > .machine keyring. > > Unfortunately I don't think there is any choice, but to define a new > MAINTAINERS entry. Perhaps something along the lines of: > > KEYS/KEYRINGS_INTEGRITY > M: Jarkko Sakkinen <jarkko@kernel.org> > M: Mimi Zohar <zohar@linux.ibm.com> > L: keyrings@vger.kernel.org > L: linux-integrity@vger.kernel.org > F: security/integrity/platform_certs > > thanks, > > Mimi This would work for me. BR, Jarkko
On Sun, 2022-02-20 at 20:00 +0100, Jarkko Sakkinen wrote: > On Wed, Jan 26, 2022 at 05:06:09PM -0500, Mimi Zohar wrote: > > > > > > Mimi brought up that we need a MAINTAINERS update for this and also > > > .platform. > > > > > > We have these: > > > > > > - KEYS/KEYRINGS > > > - CERTIFICATE HANDLING > > > > > > I would put them under KEYRINGS for now and would not consider further > > > subdivision for the moment. > > > > IMA has dependencies on the platform_certs/ and now on the new .machine > > keyring. Just adding "F: security/integrity/platform_certs/" to the > > KEYS/KEYRINGS record, ignores that dependency. The discussion wouldn't > > even be on the linux-integrity mailing list. > > > > Existing requirement: > > - The keys on the .platform keyring are limited to verifying the kexec > > image. > > > > New requirements based on Eric Snowbergs' patch set: > > - When IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY is enabled, > > the MOK keys will not be loaded directly onto the .machine keyring or > > indirectly onto the .secondary_trusted_keys keyring. > > > > - Only when a new IMA Kconfig explicitly allows the keys on the > > .machine keyrings, will the CA keys stored in MOK be loaded onto the > > .machine keyring. > > > > Unfortunately I don't think there is any choice, but to define a new > > MAINTAINERS entry. Perhaps something along the lines of: > > > > KEYS/KEYRINGS_INTEGRITY > > M: Jarkko Sakkinen <jarkko@kernel.org> > > M: Mimi Zohar <zohar@linux.ibm.com> > > L: keyrings@vger.kernel.org > > L: linux-integrity@vger.kernel.org > > F: security/integrity/platform_certs > > > > This would work for me. Thanks, Jarkko. Are you planning on upstreaming this change, as you previously said, or would you prefer I do it? thanks, Mimi
On Tue, Feb 22, 2022 at 06:59:25AM -0500, Mimi Zohar wrote: > On Sun, 2022-02-20 at 20:00 +0100, Jarkko Sakkinen wrote: > > On Wed, Jan 26, 2022 at 05:06:09PM -0500, Mimi Zohar wrote: > > > > > > > > > Mimi brought up that we need a MAINTAINERS update for this and also > > > > .platform. > > > > > > > > We have these: > > > > > > > > - KEYS/KEYRINGS > > > > - CERTIFICATE HANDLING > > > > > > > > I would put them under KEYRINGS for now and would not consider further > > > > subdivision for the moment. > > > > > > IMA has dependencies on the platform_certs/ and now on the new .machine > > > keyring. Just adding "F: security/integrity/platform_certs/" to the > > > KEYS/KEYRINGS record, ignores that dependency. The discussion wouldn't > > > even be on the linux-integrity mailing list. > > > > > > Existing requirement: > > > - The keys on the .platform keyring are limited to verifying the kexec > > > image. > > > > > > New requirements based on Eric Snowbergs' patch set: > > > - When IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY is enabled, > > > the MOK keys will not be loaded directly onto the .machine keyring or > > > indirectly onto the .secondary_trusted_keys keyring. > > > > > > - Only when a new IMA Kconfig explicitly allows the keys on the > > > .machine keyrings, will the CA keys stored in MOK be loaded onto the > > > .machine keyring. > > > > > > Unfortunately I don't think there is any choice, but to define a new > > > MAINTAINERS entry. Perhaps something along the lines of: > > > > > > KEYS/KEYRINGS_INTEGRITY > > > M: Jarkko Sakkinen <jarkko@kernel.org> > > > M: Mimi Zohar <zohar@linux.ibm.com> > > > L: keyrings@vger.kernel.org > > > L: linux-integrity@vger.kernel.org > > > F: security/integrity/platform_certs > > > > > > > This would work for me. > > Thanks, Jarkko. Are you planning on upstreaming this change, as you > previously said, or would you prefer I do it? > > thanks, > > Mimi This is the problem I'm encountering: https://lore.kernel.org/keyrings/YhLNYxBTbKW62vtC@iki.fi/ BR, Jarkko
On Tue, 2022-02-22 at 13:26 +0100, Jarkko Sakkinen wrote: > On Tue, Feb 22, 2022 at 06:59:25AM -0500, Mimi Zohar wrote: > > On Sun, 2022-02-20 at 20:00 +0100, Jarkko Sakkinen wrote: > > > On Wed, Jan 26, 2022 at 05:06:09PM -0500, Mimi Zohar wrote: > > > > > > > > > > > > Mimi brought up that we need a MAINTAINERS update for this and also > > > > > .platform. > > > > > > > > > > We have these: > > > > > > > > > > - KEYS/KEYRINGS > > > > > - CERTIFICATE HANDLING > > > > > > > > > > I would put them under KEYRINGS for now and would not consider further > > > > > subdivision for the moment. > > > > > > > > IMA has dependencies on the platform_certs/ and now on the new .machine > > > > keyring. Just adding "F: security/integrity/platform_certs/" to the > > > > KEYS/KEYRINGS record, ignores that dependency. The discussion wouldn't > > > > even be on the linux-integrity mailing list. > > > > > > > > Existing requirement: > > > > - The keys on the .platform keyring are limited to verifying the kexec > > > > image. > > > > > > > > New requirements based on Eric Snowbergs' patch set: > > > > - When IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY is enabled, > > > > the MOK keys will not be loaded directly onto the .machine keyring or > > > > indirectly onto the .secondary_trusted_keys keyring. > > > > > > > > - Only when a new IMA Kconfig explicitly allows the keys on the > > > > .machine keyrings, will the CA keys stored in MOK be loaded onto the > > > > .machine keyring. > > > > > > > > Unfortunately I don't think there is any choice, but to define a new > > > > MAINTAINERS entry. Perhaps something along the lines of: > > > > > > > > KEYS/KEYRINGS_INTEGRITY > > > > M: Jarkko Sakkinen <jarkko@kernel.org> > > > > M: Mimi Zohar <zohar@linux.ibm.com> > > > > L: keyrings@vger.kernel.org > > > > L: linux-integrity@vger.kernel.org > > > > F: security/integrity/platform_certs > > > > > > > > > > This would work for me. > > > > Thanks, Jarkko. Are you planning on upstreaming this change, as you > > previously said, or would you prefer I do it? > > > This is the problem I'm encountering: > > https://lore.kernel.org/keyrings/YhLNYxBTbKW62vtC@iki.fi/ That's the answer to a different question. :) I was asking about the MAINTAINERS record.
On Tue, 2022-02-22 at 13:26 +0100, Jarkko Sakkinen wrote: > This is the problem I'm encountering: > > https://lore.kernel.org/keyrings/YhLNYxBTbKW62vtC@iki.fi/ Try using the Message-Id: < 20220126025834.255493-1-eric.snowberg@oracle.com>
On Tue, Feb 22, 2022 at 07:32:20AM -0500, Mimi Zohar wrote: > On Tue, 2022-02-22 at 13:26 +0100, Jarkko Sakkinen wrote: > > On Tue, Feb 22, 2022 at 06:59:25AM -0500, Mimi Zohar wrote: > > > On Sun, 2022-02-20 at 20:00 +0100, Jarkko Sakkinen wrote: > > > > On Wed, Jan 26, 2022 at 05:06:09PM -0500, Mimi Zohar wrote: > > > > > > > > > > > > > > > Mimi brought up that we need a MAINTAINERS update for this and also > > > > > > .platform. > > > > > > > > > > > > We have these: > > > > > > > > > > > > - KEYS/KEYRINGS > > > > > > - CERTIFICATE HANDLING > > > > > > > > > > > > I would put them under KEYRINGS for now and would not consider further > > > > > > subdivision for the moment. > > > > > > > > > > IMA has dependencies on the platform_certs/ and now on the new .machine > > > > > keyring. Just adding "F: security/integrity/platform_certs/" to the > > > > > KEYS/KEYRINGS record, ignores that dependency. The discussion wouldn't > > > > > even be on the linux-integrity mailing list. > > > > > > > > > > Existing requirement: > > > > > - The keys on the .platform keyring are limited to verifying the kexec > > > > > image. > > > > > > > > > > New requirements based on Eric Snowbergs' patch set: > > > > > - When IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY is enabled, > > > > > the MOK keys will not be loaded directly onto the .machine keyring or > > > > > indirectly onto the .secondary_trusted_keys keyring. > > > > > > > > > > - Only when a new IMA Kconfig explicitly allows the keys on the > > > > > .machine keyrings, will the CA keys stored in MOK be loaded onto the > > > > > .machine keyring. > > > > > > > > > > Unfortunately I don't think there is any choice, but to define a new > > > > > MAINTAINERS entry. Perhaps something along the lines of: > > > > > > > > > > KEYS/KEYRINGS_INTEGRITY > > > > > M: Jarkko Sakkinen <jarkko@kernel.org> > > > > > M: Mimi Zohar <zohar@linux.ibm.com> > > > > > L: keyrings@vger.kernel.org > > > > > L: linux-integrity@vger.kernel.org > > > > > F: security/integrity/platform_certs > > > > > > > > > > > > > This would work for me. > > > > > > Thanks, Jarkko. Are you planning on upstreaming this change, as you > > > previously said, or would you prefer I do it? > > > > > This is the problem I'm encountering: > > > > https://lore.kernel.org/keyrings/YhLNYxBTbKW62vtC@iki.fi/ > > That's the answer to a different question. :) I was asking about the > MAINTAINERS record. Aaaaa... sorry! Yeah, please do it :-) BR, Jarkko
On Tue, Feb 22, 2022 at 08:43:18AM -0500, Mimi Zohar wrote: > On Tue, 2022-02-22 at 13:26 +0100, Jarkko Sakkinen wrote: > > This is the problem I'm encountering: > > > > https://lore.kernel.org/keyrings/YhLNYxBTbKW62vtC@iki.fi/ > > Try using the Message-Id: < > 20220126025834.255493-1-eric.snowberg@oracle.com> > > -- > thanks, > > Mimi OK, now the patch set is fully applied. Thank you Mimi, and Eric, apologies for the confusion. BR, Jarkko
Back in 2013 Linus requested a feature to allow end-users to have the ability "to add their own keys and sign modules they trust". This was his *second* order outlined here [1]. There have been many attempts over the years to solve this problem, all have been rejected. Many of the failed attempts loaded all preboot firmware keys into the kernel, including the Secure Boot keys. Many distributions carry one of these rejected attempts [2], [3], [4]. This series tries to solve this problem with a solution that takes into account all the problems brought up in the previous attempts. On UEFI based systems, this series introduces a new Linux kernel keyring containing the Machine Owner Keys (MOK) called machine. It also defines a new MOK variable in shim. This variable allows the end-user to decide if they want to load MOK keys into the machine keyring. By default, nothing changes; MOK keys are not loaded into the machine keyring. They are only loaded after the end-user makes the decision themselves. The end-user would set this through mokutil using a new --trust-mok option [5]. This would work similar to how the kernel uses MOK variables to enable/disable signature validation as well as use/ignore the db. Any kernel operation that uses either the builtin or secondary trusted keys as a trust source shall also reference the new machine keyring as a trust source. Secure Boot keys will never be loaded into the machine keyring. They will always be loaded into the platform keyring. If an end-user wanted to load one, they would need to enroll it into the MOK. Unlike previous versions of this patch set, IMA support has been removed to simplify the series. After acceptance, a follow-on series will add IMA support. Steps required by the end user: Sign kernel module with user created key: $ /usr/src/kernels/$(uname -r)/scripts/sign-file sha512 \ machine_signing_key.priv machine_signing_key.x509 my_module.ko Import the key into the MOK $ mokutil --import machine_signing_key.x509 Setup the kernel to load MOK keys into the .machine keyring $ mokutil --trust-mok Then reboot, the MokManager will load and ask if you want to trust the MOK key and enroll the MOK into the MOKList. Afterwards the signed kernel module will load. I have included a link to the mokutil [5] changes I have made to support this new functionality. The shim changes have now been accepted upstream [6]. Upstream shim is located here [7], the build instructions are here [8]. TLDR: $ git clone --recurse-submodules https://github.com/rhboot/shim $ cd shim $ make After building shim, move shimx64.efi and mmx64.efi to the vendor or distribution specific directory on your EFI System Partition (assuming you are building on x86). The instructions above are the minimal steps needed to build shim to test this feature. It is assumed Secure Boot shall not be enabled for this testing. To do testing with Secure Boot enabled, all steps in the build instructions [8] must be followed. Instructions for building mokutil (including the new changes): $ git clone -b mokvars-v3 https://github.com/esnowberg/mokutil.git $ cd mokutil/ $ ./autogen.sh $ make [1] https://marc.info/?l=linux-kernel&m=136185386310140&w=2 [2] https://lore.kernel.org/lkml/1479737095.2487.34.camel@linux.vnet.ibm.com/ [3] https://lore.kernel.org/lkml/1556221605.24945.3.camel@HansenPartnership.com/ [4] https://lore.kernel.org/linux-integrity/1e41f22b1f11784f1e943f32bf62034d4e054cdb.camel@HansenPartnership.com/ [5] https://github.com/esnowberg/mokutil/tree/mokvars-v3 [6] https://github.com/rhboot/shim/commit/4e513405b4f1641710115780d19dcec130c5208f [7] https://github.com/rhboot/shim [8] https://github.com/rhboot/shim/blob/main/BUILDING Eric Snowberg (8): integrity: Fix warning about missing prototypes integrity: Introduce a Linux keyring called machine integrity: add new keyring handler for mok keys KEYS: store reference to machine keyring KEYS: Introduce link restriction for machine keys efi/mokvar: move up init order integrity: Trust MOK keys if MokListTrustedRT found integrity: Only use machine keyring when uefi_check_trust_mok_keys is true certs/system_keyring.c | 44 ++++++++++- drivers/firmware/efi/mokvar-table.c | 2 +- include/keys/system_keyring.h | 14 ++++ security/integrity/Kconfig | 13 ++++ security/integrity/Makefile | 1 + security/integrity/digsig.c | 15 +++- security/integrity/integrity.h | 17 +++- .../platform_certs/keyring_handler.c | 18 ++++- .../platform_certs/keyring_handler.h | 5 ++ security/integrity/platform_certs/load_uefi.c | 4 +- .../platform_certs/machine_keyring.c | 77 +++++++++++++++++++ 11 files changed, 202 insertions(+), 8 deletions(-) create mode 100644 security/integrity/platform_certs/machine_keyring.c base-commit: e783362eb54cd99b2cac8b3a9aeac942e6f6ac07