On Mon, 24 Feb 2020 at 15:47, Corentin Labbe <clabbe@xxxxxxxxxxxx> wrote:
>
> When an ahash algorithm fallback to another ahash and that fallback is
> shaXXX-CE, doing export/import lead to error like this:
> alg: ahash: sha1-sun8i-ce export() overran state buffer on test vector 0, cfg=\"import/export\"
>
> This is due to the descsize of shaxxx-ce being larger than struct shaxxx_state
> off by an u32.
> For fixing this, let's implement export/import which rip the finalize
> variant instead of using generic export/import.
>
> Fixes: 6ba6c74dfc6b ("arm64/crypto: SHA-224/SHA-256 using ARMv8 Crypto Extensions")
> Fixes: 2c98833a42cd ("arm64/crypto: SHA-1 using ARMv8 Crypto Extensions")
>
> Signed-off-by: Corentin Labbe <clabbe@xxxxxxxxxxxx>
Reviewed-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
> ---
> Changes since v1:
> - memcpy directly &sctx->sst instead of sctx. As suggested by Eric Biggers
>
> arch/arm64/crypto/sha1-ce-glue.c | 20 ++++++++++++++++++++
> arch/arm64/crypto/sha2-ce-glue.c | 23 +++++++++++++++++++++++
> 2 files changed, 43 insertions(+)
>
> diff --git a/arch/arm64/crypto/sha1-ce-glue.c b/arch/arm64/crypto/sha1-ce-glue.c
> index 63c875d3314b..565ef604ca04 100644
> --- a/arch/arm64/crypto/sha1-ce-glue.c
> +++ b/arch/arm64/crypto/sha1-ce-glue.c
> @@ -91,12 +91,32 @@ static int sha1_ce_final(struct shash_desc *desc, u8 *out)
> return sha1_base_finish(desc, out);
> }
>
> +static int sha1_ce_export(struct shash_desc *desc, void *out)
> +{
> + struct sha1_ce_state *sctx = shash_desc_ctx(desc);
> +
> + memcpy(out, &sctx->sst, sizeof(struct sha1_state));
> + return 0;
> +}
> +
> +static int sha1_ce_import(struct shash_desc *desc, const void *in)
> +{
> + struct sha1_ce_state *sctx = shash_desc_ctx(desc);
> +
> + memcpy(&sctx->sst, in, sizeof(struct sha1_state));
> + sctx->finalize = 0;
> + return 0;
> +}
> +
> static struct shash_alg alg = {
> .init = sha1_base_init,
> .update = sha1_ce_update,
> .final = sha1_ce_final,
> .finup = sha1_ce_finup,
> + .import = sha1_ce_import,
> + .export = sha1_ce_export,
> .descsize = sizeof(struct sha1_ce_state),
> + .statesize = sizeof(struct sha1_state),
> .digestsize = SHA1_DIGEST_SIZE,
> .base = {
> .cra_name = "sha1",
> diff --git a/arch/arm64/crypto/sha2-ce-glue.c b/arch/arm64/crypto/sha2-ce-glue.c
> index a8e67bafba3d..9450d19b9e6e 100644
> --- a/arch/arm64/crypto/sha2-ce-glue.c
> +++ b/arch/arm64/crypto/sha2-ce-glue.c
> @@ -109,12 +109,32 @@ static int sha256_ce_final(struct shash_desc *desc, u8 *out)
> return sha256_base_finish(desc, out);
> }
>
> +static int sha256_ce_export(struct shash_desc *desc, void *out)
> +{
> + struct sha256_ce_state *sctx = shash_desc_ctx(desc);
> +
> + memcpy(out, &sctx->sst, sizeof(struct sha256_state));
> + return 0;
> +}
> +
> +static int sha256_ce_import(struct shash_desc *desc, const void *in)
> +{
> + struct sha256_ce_state *sctx = shash_desc_ctx(desc);
> +
> + memcpy(&sctx->sst, in, sizeof(struct sha256_state));
> + sctx->finalize = 0;
> + return 0;
> +}
> +
> static struct shash_alg algs[] = { {
> .init = sha224_base_init,
> .update = sha256_ce_update,
> .final = sha256_ce_final,
> .finup = sha256_ce_finup,
> + .export = sha256_ce_export,
> + .import = sha256_ce_import,
> .descsize = sizeof(struct sha256_ce_state),
> + .statesize = sizeof(struct sha256_state),
> .digestsize = SHA224_DIGEST_SIZE,
> .base = {
> .cra_name = "sha224",
> @@ -128,7 +148,10 @@ static struct shash_alg algs[] = { {
> .update = sha256_ce_update,
> .final = sha256_ce_final,
> .finup = sha256_ce_finup,
> + .export = sha256_ce_export,
> + .import = sha256_ce_import,
> .descsize = sizeof(struct sha256_ce_state),
> + .statesize = sizeof(struct sha256_state),
> .digestsize = SHA256_DIGEST_SIZE,
> .base = {
> .cra_name = "sha256",
> --
> 2.24.1
>
