Re: [RFT PATCH] crypto: ahash.c: Require export/import in ahash

From: Bartlomiej Zolnierkiewicz
Date: Tue Jan 16 2018 - 07:20:21 EST


On Tuesday, January 16, 2018 11:35:44 AM Kamil Konieczny wrote:
> Export and import were optional in async hash. As drivers were rewritten,
> they become mandatory now, so correct init of ahash transformation.
>
> Signed-off-by: Kamil Konieczny <k.konieczny@xxxxxxxxxxxxxxxxxxx>
> ---
> Tested with crypto run-time self test on Odroid-U3 with Exynos 4412 CPU,
> with insmod s5p-sss.ko
> Please test with other crypto hash drivers.

Testing all existing ahash drivers is impossible so the code audit
should be done instead. From the quick look there are 3 hash drivers
left that still don't implement ->import/->export methods:

drivers/crypto/mxs-dcp.c
drivers/crypto/n2_core.c
drivers/crypto/ux500/hash/hash_core.c

It seems that after this patch they will OOPS, currently they now
return errors on ->import/->export attempts.

Please verify this and if necessary add dummy ->import/->export
implementations to affected drivers + contact their maintainers
(or authors if there is no maintainer assigned) to make them
aware of the problem (maybe some drivers should be removed now?).

> crypto/ahash.c | 18 ++----------------
> 1 file changed, 2 insertions(+), 16 deletions(-)
>
> diff --git a/crypto/ahash.c b/crypto/ahash.c
> index 3a35d67de7d9..7a8906d5af53 100644
> --- a/crypto/ahash.c
> +++ b/crypto/ahash.c
> @@ -434,16 +434,6 @@ static int ahash_def_finup(struct ahash_request *req)
> return ahash_def_finup_finish1(req, err);
> }
>
> -static int ahash_no_export(struct ahash_request *req, void *out)
> -{
> - return -ENOSYS;
> -}
> -
> -static int ahash_no_import(struct ahash_request *req, const void *in)
> -{
> - return -ENOSYS;
> -}
> -
> static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
> {
> struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
> @@ -451,8 +441,8 @@ static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
>
> hash->setkey = ahash_nosetkey;
> hash->has_setkey = false;
> - hash->export = ahash_no_export;
> - hash->import = ahash_no_import;
> + hash->export = alg->export;
> + hash->import = alg->import;
>
> if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
> return crypto_init_shash_ops_async(tfm);
> @@ -467,10 +457,6 @@ static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
> hash->setkey = alg->setkey;
> hash->has_setkey = true;
> }
> - if (alg->export)
> - hash->export = alg->export;
> - if (alg->import)
> - hash->import = alg->import;
>
> return 0;
> }

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics