Re: [PATCH v2 0/7] crypto: sha256 - Merge 2 separate C implementations into 1, put into separate library

[Ard Biesheuvel]

On Sat, 17 Aug 2019 at 17:24, Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
>
> Hi All,
>
> Here is v2 of my patch series refactoring the current 2 separate SHA256
> C implementations into 1 and put it into a separate library.
>
> There are 3 reasons for this:
>
> 1) Remove the code duplication of having 2 separate implementations
>
> 2) Offer a separate library SHA256 implementation which can be used
> without having to call crypto_alloc_shash first. This is especially
> useful for use during early boot when crypto_alloc_shash does not
> work yet.
>
> 3) Having the purgatory code using the same code as the crypto subsys means
> that the purgratory code will be tested by the crypto subsys selftests.
>
> This has been tested on x86, including checking that kecec still works.
>
> This has NOT been tested on s390, if someone with access to s390 can
> test that things still build with this series applied and that
> kexec still works, that would be great.
>
> Changes in v2:
> - Use put_unaligned_be32 to store the hash to allow callers to use an
>   unaligned buffer for storing the hash
> - Add a comment to include/crypto/sha256.h explaining that these functions
>   now may be used outside of the purgatory too (and that using the crypto
>   API instead is preferred)
> - Add sha224 support to the lib/crypto/sha256 library code
> - Make crypto/sha256_generic.c not only use sha256_transform from
>   lib/crypto/sha256.c but also switch it to using sha256_init, sha256_update
>   and sha256_final from there so that the crypto subsys selftests fully test
>   the lib/crypto/sha256.c implementation
>

This looks fine to me, although I agree with Eric's feedback regarding
further cleanups. Also, now that we have a C library, I'd like to drop
the dependency of the mips and x86 sha256 algo implementations up
sha256_generic.c, and use the library directly instead (so that
sha256-generic is no longer needed on x86 or mips)