Re: [PATCH] efi: select CRYPTO for EFI_EMBEDDED_FIRMWARE

Re: [PATCH] efi: select CRYPTO for EFI_EMBEDDED_FIRMWARE

[Ard Biesheuvel]

(+ crypto folks)

On Fri, 15 Oct 2021 at 15:24, Vegard Nossum <vegard.nossum@oracle.com> wrote:
>
> Fix the following build warning:
>
>   WARNING: unmet direct dependencies detected for CRYPTO_LIB_SHA256
>     Depends on [n]: CRYPTO [=n]
>     Selected by [y]:
>     - EFI_EMBEDDED_FIRMWARE [=y] && EFI [=y]
>
> Fixes: f0df68d5bae88 ("efi: Add embedded peripheral firmware support")
> Cc: Hans de Goede <hdegoede@redhat.com>
> Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>

Hello Vegard,

I don't think this is the right fix, to be honest. The crypto library
functions have no dependencies at all on the crypto API, so I think it
would be better to do something like the below:

diff --git a/crypto/Kconfig b/crypto/Kconfig
index 536df4b6b825..b79de4820ce9 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -1919,9 +1919,10 @@ config CRYPTO_STATS
 config CRYPTO_HASH_INFO
        bool

-source "lib/crypto/Kconfig"
 source "drivers/crypto/Kconfig"
 source "crypto/asymmetric_keys/Kconfig"
 source "certs/Kconfig"

 endif  # if CRYPTO
+
+source "lib/crypto/Kconfig"


> ---
>  drivers/firmware/efi/Kconfig | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig
> index 2c3dac5ecb36d..f914da9845acc 100644
> --- a/drivers/firmware/efi/Kconfig
> +++ b/drivers/firmware/efi/Kconfig
> @@ -248,6 +248,7 @@ endmenu
>  config EFI_EMBEDDED_FIRMWARE
>         bool
>         depends on EFI
> +       select CRYPTO
>         select CRYPTO_LIB_SHA256
>
>  config UEFI_CPER
> --
> 2.23.0.718.g5ad94255a8
>

Re: [PATCH] efi: select CRYPTO for EFI_EMBEDDED_FIRMWARE

[Eric Biggers]

On Fri, Oct 15, 2021 at 03:55:01PM +0200, Ard Biesheuvel wrote:
> (+ crypto folks)
> 
> On Fri, 15 Oct 2021 at 15:24, Vegard Nossum <vegard.nossum@oracle.com> wrote:
> >
> > Fix the following build warning:
> >
> >   WARNING: unmet direct dependencies detected for CRYPTO_LIB_SHA256
> >     Depends on [n]: CRYPTO [=n]
> >     Selected by [y]:
> >     - EFI_EMBEDDED_FIRMWARE [=y] && EFI [=y]
> >
> > Fixes: f0df68d5bae88 ("efi: Add embedded peripheral firmware support")
> > Cc: Hans de Goede <hdegoede@redhat.com>
> > Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
> 
> Hello Vegard,
> 
> I don't think this is the right fix, to be honest. The crypto library
> functions have no dependencies at all on the crypto API, so I think it
> would be better to do something like the below:

Actually some of the crypto library functions need __crypto_xor() and
__crypto_memneq() which are only compiled when CRYPTO.  So that will need to be
fixed by moving those functions to an appropriate place first.

- Eric