[PATCH v4 04/29] lib: Adapt digest header files to MbedTLS

[Raymond Mao]

Hi Tom,

On Tue, 2 Jul 2024 at 18:48, Tom Rini <trini at konsulko.com> wrote:

> On Tue, Jul 02, 2024 at 11:22:40AM -0700, Raymond Mao wrote:
>
> > Adapt digest header files to support both original libs and MbedTLS
> > by switching on/off MBEDTLS_LIB_CRYPTO.
> > Introduce <alg>_LEGACY kconfig for legacy hash implementations.
> [snip]
> > diff --git a/lib/mbedtls/Kconfig b/lib/mbedtls/Kconfig
> > index 3e9057f1acf..6662a9d20f1 100644
> > --- a/lib/mbedtls/Kconfig
> > +++ b/lib/mbedtls/Kconfig
> > @@ -21,9 +21,105 @@ if LEGACY_CRYPTO
> >
> >  config LEGACY_CRYPTO_BASIC
> >       bool "legacy basic crypto libraries"
> > +     select MD5_LEGACY if MD5
> > +     select SHA1_LEGACY if SHA1
> > +     select SHA256_LEGACY if SHA256
> > +     select SHA512_LEGACY if SHA512
> > +     select SHA384_LEGACY if SHA384
> > +     select SPL_MD5_LEGACY if MD5 && SPL
> > +     select SPL_SHA1_LEGACY if SHA1 && SPL
> > +     select SPL_SHA256_LEGACY if SHA256 && SPL
> > +     select SPL_SHA512_LEGACY if SHA512 && SPL
> > +     select SPL_SHA384_LEGACY if SHA384 && SPL
> >       help
> >         Enable legacy basic crypto libraries.
> >
> > +if LEGACY_CRYPTO_BASIC
> > +
> > +config SHA1_LEGACY
> > +     bool "Enable SHA1 support with legacy crypto library"
> > +     depends on LEGACY_CRYPTO_BASIC && SHA1
> > +     help
> > +       This option enables support of hashing using SHA1 algorithm
> > +       with legacy crypto library.
> > +
> > +config SHA256_LEGACY
> > +     bool "Enable SHA256 support with legacy crypto library"
> > +     depends on LEGACY_CRYPTO_BASIC && SHA256
> > +     help
> > +       This option enables support of hashing using SHA256 algorithm
> > +       with legacy crypto library.
> > +
> > +config SHA512_LEGACY
> > +     bool "Enable SHA512 support with legacy crypto library"
> > +     depends on LEGACY_CRYPTO_BASIC && SHA512
> > +     default y if TI_SECURE_DEVICE && FIT_SIGNATURE
> > +     help
> > +       This option enables support of hashing using SHA512 algorithm
> > +       with legacy crypto library.
> > +
> > +config SHA384_LEGACY
> > +     bool "Enable SHA384 support with legacy crypto library"
> > +     depends on LEGACY_CRYPTO_BASIC && SHA384
> > +     select SHA512_LEGACY
> > +     help
> > +       This option enables support of hashing using SHA384 algorithm
> > +       with legacy crypto library.
> > +
> > +config MD5_LEGACY
> > +     bool "Enable MD5 support with legacy crypto library"
> > +     depends on LEGACY_CRYPTO_BASIC && MD5
> > +     help
> > +       This option enables support of hashing using MD5 algorithm
> > +       with legacy crypto library.
> > +
> > +if SPL
> > +
> > +config SPL_SHA1_LEGACY
> > +     bool "Enable SHA1 support in SPL with legacy crypto library"
> > +     depends on LEGACY_CRYPTO_BASIC && SPL_SHA1
> > +     default y if SHA1 && LEGACY_CRYPTO_BASIC
> > +     help
> > +       This option enables support of hashing using SHA1 algorithm
> > +       with legacy crypto library.
> > +
> > +config SPL_SHA256_LEGACY
> > +     bool "Enable SHA256 support in SPL with legacy crypto library"
> > +     depends on LEGACY_CRYPTO_BASIC && SPL_SHA256
> > +     default y if SHA256 && LEGACY_CRYPTO_BASIC
> > +     help
> > +       This option enables support of hashing using SHA256 algorithm
> > +       with legacy crypto library.
> > +
> > +config SPL_SHA512_LEGACY
> > +     bool "Enable SHA512 support in SPL with legacy crypto library"
> > +     depends on LEGACY_CRYPTO_BASIC && SPL_SHA512
> > +     default y if SHA512 && LEGACY_CRYPTO_BASIC
> > +     help
> > +       This option enables support of hashing using SHA512 algorithm
> > +       with legacy crypto library.
> > +
> > +config SPL_SHA384_LEGACY
> > +     bool "Enable SHA384 support in SPL with legacy crypto library"
> > +     depends on LEGACY_CRYPTO_BASIC && SPL_SHA384
> > +     default y if SHA384 && LEGACY_CRYPTO_BASIC
> > +     select SPL_SHA512
> > +     help
> > +       This option enables support of hashing using SHA384 algorithm
> > +       with legacy crypto library.
> > +
> > +config SPL_MD5_LEGACY
> > +     bool "Enable MD5 support in SPL with legacy crypto library"
> > +     depends on LEGACY_CRYPTO_BASIC && SPL_MD5
> > +     default y if MD5 && LEGACY_CRYPTO_BASIC
> > +     help
> > +       This option enables support of hashing using MD5 algorithm
> > +       with legacy crypto library.
> > +
> > +endif # SPL
> > +
> > +endif # LEGACY_CRYPTO_BASIC
> > +
> >  config LEGACY_CRYPTO_CERT
> >       bool "legacy certificate libraries"
> >       help
>
> This is all certainly moving in the right direction, but there's
> dependency issues:
>    aarch64:  w+   xilinx_zynqmp_kria
> +(xilinx_zynqmp_kria)
> +(xilinx_zynqmp_kria) WARNING: unmet direct dependencies detected for
> SPL_MD5_LEGACY
> +(xilinx_zynqmp_kria)   Depends on [n]: LEGACY_CRYPTO [=y] && SPL [=y] &&
> LEGACY_CRYPTO_BASIC [=y] && SPL_MD5 [=n]
> +(xilinx_zynqmp_kria)   Selected by [y]:
> +(xilinx_zynqmp_kria)   - LEGACY_CRYPTO_BASIC [=y] && LEGACY_CRYPTO [=y]
> && MD5 [=y] && SPL [=y]
>

I am a bit confused by SPL_MD5, why it is [n] when both MD5 and SPL are [y].
Of course we can replace 'SPL_MD5' with 'MD5 && SPL' to solve the warning,
but I guess the wrong dependence is on SPL_MD5 but not the new added ones.
```
config SPL_MD5
bool "Support MD5 algorithm in SPL"
depends on SPL
```
I think it should be 'default y if SPL && MD5' instead of 'depends on SPL'.

Similarly SPL_ASYMMETRIC_PUBLIC_KEY_SUBTYPE is not selected when both
ASYMMETRIC_PUBLIC_KEY_SUBTYPE
and SPL are selected;
SPL_ASN1_DECODER is not selected when both ASN1_DECODER and SPL are
selected.

I think generally for each algorithm, 'SPL_<ALG>' config should be selected
when both 'SPL' and '<ALG>' are selected.

If you agree I can fix this in the next patch set.

Regards,
Raymond