Hi François, On Tue, 9 Nov 2021 at 05:43, François Ozog <francois.o...@linaro.org> wrote: > > Hi > > as we are in design discussions, I would promote the idea of not pushing > non hardware related things in the DTB that is passed to the kernel. > Is your use case to allow U-Boot to verify the kernel's signature ? > Why not putting it into an environment variable?
We have been through this many times but I'll state it again. U-Boot makes use of the devicetree for configuration information, including public keys, etc. It does not belong anywhere else. http://patchwork.ozlabs.org/project/uboot/patch/20211026002344.405160-3-...@chromium.org/ > > If your use case is on Arm or RISC-V, both environments are working heavily > to make https://arm-software.github.io/ebbr/ standard available on a large > number of boards. > This offers UEFI interface and SecureBoot (and later MeasuredBoot) > services. For Arm boards just check for SystemReady compliance. > In this context, traditional UEFI secure variables are used to deal with > certificates and hashes: PK, KEK, db... > You can obviously do differently but you will be on your own to extend the > chain of trust to IMA, secure containers (rooted down to hRoT) and other > security facilities in the Linux side. > Could you describe your use case in more details? > That feature does not use FIT images, nor U-Boot's verified boot. Regards, Simon > On Tue, 9 Nov 2021 at 11:07, Jan Kiszka <jan.kis...@siemens.com> wrote: > > > On 09.11.21 10:37, Roman Kopytin wrote: > > > Can we have discussion with code lines? For me it is not very clear, > > because it isn't my code. > > > > > > > Please do not top-post. > > > > > -----Original Message----- > > > From: Jan Kiszka <jan.kis...@siemens.com> > > > Sent: Tuesday, November 9, 2021 12:17 PM > > > To: Roman Kopytin <roman.kopy...@kaspersky.com>; u-boot@lists.denx.de; > > Rasmus Villemoes <rasmus.villem...@prevas.dk> > > > Subject: Re: [PATCH 0/2] RFC: add fdt_add_pubkey tool > > > > > > On 08.11.21 16:28, Roman Kopytin wrote: > > >> In order to reduce the coupling between building the kernel and > > >> U-Boot, I'd like a tool that can add a public key to U-Boot's dtb > > >> without simultaneously signing a FIT image. That tool doesn't seem to > > >> exist, so I stole the necessary pieces from mkimage et al and put it > > >> in a single .c file. > > >> > > >> I'm still working on the details of my proposed "require just k out > > >> these n required keys" and how it should be implemented, but it will > > >> probably involve teaching this tool a bunch of new options. These > > >> patches are not necessarily ready for inclusion (unless someone else > > >> finds fdt_add_pubkey useful as is), but I thought I might as well send > > >> it out for early comments. > > > > > > I'd also like to see the usage of this hooked into the build process. > > > > > > And to my understanding of [1], that approach will provide a feature > > that permits hooking with the build but would expect the key as dtsi > > fragment. Can we consolidate the approaches? > > > > > > My current vision of a user interface would be a Kconfig option that > > takes a list of key files to be injected. Maybe make that three lists, one > > for "required=image", one for "required=conf", and one for optional keys > > (if that has a use case in practice, no idea). > > > > > > Jan > > > > > > [1] > > > > > https://lore.kernel.org/u-boot/20210928085651.619892-1-rasmus.villem...@prevas.dk/ > > > > > > -- > > > Siemens AG, T RDA IOT > > > Corporate Competence Center Embedded Linux > > > > > > > For what would you like to have code? The kconfig addition? > > > > diff --git a/common/Kconfig.boot b/common/Kconfig.boot > > index d3a12be228..a9ed4d4ec4 100644 > > --- a/common/Kconfig.boot > > +++ b/common/Kconfig.boot > > @@ -279,6 +279,14 @@ config SPL_FIT_GENERATOR > > > > endif # SPL > > > > +config FIT_SIGNATURE_PUB_KEYS > > + string "Public keys to use for FIT image verification" > > + depends on FIT_SIGNATURE || SPL_FIT_SIGNATURE > > + help > > + Public keys, or certificate files to extract them from, that > > shall > > + be used to verify signed FIT images. The keys will be embedded > > into > > + the control device tree of U-Boot. > > + > > endif # FIT > > > > config LEGACY_IMAGE_FORMAT > > > > > > But note that we are in a design discussion here, and I'm at least > > reluctant to code up n-versions without having some common idea where > > things should move. > > > > Jan > > > > -- > > Siemens AG, T RDA IOT > > Corporate Competence Center Embedded Linux > > > > > -- > François-Frédéric Ozog | *Director Business Development* > T: +33.67221.6485 > francois.o...@linaro.org | Skype: ffozog