[PATCH v5 03/12] capsule: authenticate: Add capsule public key in platform's dtb

[Sughosh Ganu]

hi Simon,

On Wed, 26 Jul 2023 at 04:22, Simon Glass <sjg at chromium.org> wrote:
>
> Hi Sughosh,
>
> On Tue, 25 Jul 2023 at 02:58, Sughosh Ganu <sughosh.ganu at linaro.org> wrote:
> >
> > The EFI capsule authentication logic in u-boot expects the public key
> > in the form of an EFI Signature List(ESL) to be provided as part of
> > the platform's dtb. Currently, the embedding of the ESL file into the
> > dtb needs to be done manually.
> >
> > Add a signature node in the u-boot dtsi file and include the public
> > key through the capsule-key property. This file is per architecture,
> > and is currently being added for sandbox and arm architectures. It
> > will have to be added for other architectures which need to enable
> > capsule authentication support.
> >
> > The path to the ESL file is specified through the
> > CONFIG_EFI_CAPSULE_ESL_FILE symbol.
> >
> > Signed-off-by: Sughosh Ganu <sughosh.ganu at linaro.org>
> > ---
> > Changes since V4:
> > * Fix multi line comment format.
> > * Drop additional blank line.
> > * Remove the check for CONFIG_EFI_HAVE_CAPSULE_SUPPORT from arm's
> >   u-boot.dtsi.
> > * Wrap the help text in the EFI_CAPSULE_ESL_FILE config at 72 chars.
> >

<snip>

> > diff --git a/arch/sandbox/dts/u-boot.dtsi b/arch/sandbox/dts/u-boot.dtsi
> > new file mode 100644
> > index 0000000000..60bd004937
> > --- /dev/null
> > +++ b/arch/sandbox/dts/u-boot.dtsi
> > @@ -0,0 +1,17 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/*
> > + * Devicetree file with miscellaneous nodes that will be included
> > + * at build time into the DTB. Currently being used for including
> > + * capsule related information.
> > + *
> > + */
> > +
> > +#ifdef CONFIG_EFI_HAVE_CAPSULE_SUPPORT
> > +/ {
> > +#ifdef CONFIG_EFI_CAPSULE_AUTHENTICATE
> > +       signature {
> > +               capsule-key = /incbin/(CONFIG_EFI_CAPSULE_ESL_FILE);
> > +       };
> > +#endif
> > +};
> > +#endif /* CONFIG_EFI_HAVE_CAPSULE_SUPPORT */
>
> You missed my comment there. You should not need the outer #ifdef, but
> if you do, please combine them into one #if

I did not miss your comment. The reason I have kept both the ifdefs is
that we need to include stuff which is needed only when
CONFIG_EFI_CAPSULE_AUTHENTICATE is enabled, and then the rest of the
stuff is needed only when CONFIG_EFI_HAVE_CAPSULE_SUPPORT is enabled.
Not having both the ifdefs would result in build failures. In the
u-boot.dtsi included for the arm arch, I am using a single ifdef,
since we are including only the signature node in that file.

-sughosh

>
> > diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
> > index a22e47616f..0d559ff3a1 100644
> > --- a/lib/efi_loader/Kconfig
> > +++ b/lib/efi_loader/Kconfig
> > @@ -235,6 +235,15 @@ config EFI_CAPSULE_MAX
> >           Select the max capsule index value used for capsule report
> >           variables. This value is used to create CapsuleMax variable.
> >
> > +config EFI_CAPSULE_ESL_FILE
> > +       string "Path to the EFI Signature List File"
> > +       default ""
> > +       depends on EFI_CAPSULE_AUTHENTICATE
> > +       help
> > +         Provides the absolute path to the EFI Signature List file which
> > +         will be embedded in the platform's device tree and used for
> > +         capsule authentication at the time of capsule update.
> > +
> >  config EFI_DEVICE_PATH_TO_TEXT
> >         bool "Device path to text protocol"
> >         default y
> > diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile
> > index 1a8c8d7cab..c52c9d27bd 100644
> > --- a/lib/efi_loader/Makefile
> > +++ b/lib/efi_loader/Makefile
> > @@ -89,3 +89,10 @@ obj-$(CONFIG_EFI_ECPT) += efi_conformance.o
> >
> >  EFI_VAR_SEED_FILE := $(subst $\",,$(CONFIG_EFI_VAR_SEED_FILE))
> >  $(obj)/efi_var_seed.o: $(srctree)/$(EFI_VAR_SEED_FILE)
> > +
> > +ifeq ($(CONFIG_EFI_CAPSULE_AUTHENTICATE),y)
> > +EFI_CAPSULE_KEY_PATH := $(subst $\",,$(CONFIG_EFI_CAPSULE_ESL_FILE))
> > +ifeq ("$(wildcard $(EFI_CAPSULE_KEY_PATH))","")
> > +$(error .esl cerificate not found. Configure your CONFIG_EFI_CAPSULE_ESL_FILE)
> > +endif
> > +endif
> > --
> > 2.34.1
> >
>
> Regards,
> Simon