[U-Boot] [RFC 1/3] lib: rsa: decouple rsa from FIT image verification

[Heinrich Schuchardt]

On 9/6/19 9:08 AM, AKASHI Takahiro wrote:
> Introduce new configuration, CONFIG_RSA_VERIFY which will decouple building
> RSA functions from FIT verification and allow for adding a RSA-based
> signature verification for other file formats, in particular PE file
> for UEFI secure boot.
>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
> ---
>   lib/rsa/Kconfig  | 7 +++++++
>   lib/rsa/Makefile | 2 +-
>   2 files changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/lib/rsa/Kconfig b/lib/rsa/Kconfig
> index 2b33f323bccc..338c8124da59 100644
> --- a/lib/rsa/Kconfig
> +++ b/lib/rsa/Kconfig
> @@ -1,5 +1,6 @@
>   config RSA
>   	bool "Use RSA Library"
> +	select RSA_VERIFY
>   	select RSA_FREESCALE_EXP if FSL_CAAM && !ARCH_MX7 && !ARCH_MX6 && !ARCH_MX5
>   	select RSA_SOFTWARE_EXP if !RSA_FREESCALE_EXP
>   	help
> @@ -17,6 +18,12 @@ if RSA
>
>   config SPL_RSA
>   	bool "Use RSA Library within SPL"
> +	select RSA_VERIFY
> +
> +config RSA_VERIFY
> +	bool
> +	help
> +	  Add RSA signature verification support.
>
>   config RSA_SOFTWARE_EXP
>   	bool "Enable driver for RSA Modular Exponentiation in software"
> diff --git a/lib/rsa/Makefile b/lib/rsa/Makefile
> index a51c6e1685fb..226d8f3514a9 100644
> --- a/lib/rsa/Makefile
> +++ b/lib/rsa/Makefile
> @@ -5,5 +5,5 @@
>   # (C) Copyright 2000-2007
>   # Wolfgang Denk, DENX Software Engineering, wd at denx.de.
>
> -obj-$(CONFIG_$(SPL_)FIT_SIGNATURE) += rsa-verify.o rsa-checksum.o
> +obj-$(CONFIG_RSA_VERIFY) += rsa-verify.o rsa-checksum.o
>   obj-$(CONFIG_RSA_SOFTWARE_EXP) += rsa-mod-exp.o
>

pine64-lts_defconfig with CONFIG_RSA=y
compiles fine without this patch. But with this patch:

lib/rsa/rsa-verify.c:60:5: error: redefinition of ‘padding_pkcs_15_verify’
    60 | int padding_pkcs_15_verify(struct image_sign_info *info,
       |     ^~~~~~~~~~~~~~~~~~~~~~
In file included from lib/rsa/rsa-verify.c:21:
include/u-boot/rsa.h:118:19: note: previous definition of
‘padding_pkcs_15_verify’ was here
   118 | static inline int padding_pkcs_15_verify(struct image_sign_info
*info,
       |                   ^~~~~~~~~~~~~~~~~~~~~~
lib/rsa/rsa-verify.c:399:5: error: redefinition of ‘rsa_verify’
   399 | int rsa_verify(struct image_sign_info *info,
       |     ^~~~~~~~~~
   CC      lib/efi_loader/efi_hii.o
In file included from lib/rsa/rsa-verify.c:21:
include/u-boot/rsa.h:111:19: note: previous definition of ‘rsa_verify’
was here
   111 | static inline int rsa_verify(struct image_sign_info *info,
       |                   ^~~~~~~~~~

Best regards

Heinrich