Re: [dpdk-dev] [PATCH v2 1/3] crypto/aesni_gcm: fix J0 padding bytes for GCM

["Azarewicz, PiotrX T" <piotrx.t.azarewicz@intel.com>]

Hi Arek,

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Arek Kusztal
> Sent: Friday, December 23, 2016 9:25 AM
> To: dev@dpdk.org
> Cc: Trahe, Fiona <fiona.trahe@intel.com>; De Lara Guarch, Pablo
> <pablo.de.lara.guarch@intel.com>; Griffin, John <john.griffin@intel.com>;
> Jain, Deepak K <deepak.k.jain@intel.com>; Doherty, Declan
> <declan.doherty@intel.com>; Kusztal, ArkadiuszX
> <arkadiuszx.kusztal@intel.com>
> Subject: [dpdk-dev] [PATCH v2 1/3] crypto/aesni_gcm: fix J0 padding bytes
> for GCM
> 
> This commit fixes pre-counter block (J0) padding by clearing four most
> significant bytes before setting initial counter value.
> 
> Fixes: b2bb3597470c ("crypto/aesni_gcm: move pre-counter block to driver")
> 
> Signed-off-by: Arek Kusztal <arkadiuszx.kusztal@intel.com>
> ---
>  drivers/crypto/aesni_gcm/aesni_gcm_pmd.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/crypto/aesni_gcm/aesni_gcm_pmd.c
> b/drivers/crypto/aesni_gcm/aesni_gcm_pmd.c
> index dba5e15..af3d60f 100644
> --- a/drivers/crypto/aesni_gcm/aesni_gcm_pmd.c
> +++ b/drivers/crypto/aesni_gcm/aesni_gcm_pmd.c
> @@ -40,6 +40,7 @@
>  #include <rte_vdev.h>
>  #include <rte_malloc.h>
>  #include <rte_cpuflags.h>
> +#include <rte_byteorder.h>
> 
>  #include "aesni_gcm_pmd_private.h"
> 
> @@ -241,7 +242,8 @@ process_gcm_crypto_op(struct aesni_gcm_qp *qp,
> struct rte_crypto_sym_op *op,
>  	 * to set BE LSB to 1, driver expects that 16B is allocated

I think that 16B expected by driver while only 12B IV is supported is not clear from user perspective.
I think that we should expect 12B only and allocate 16B locally.

>  	 */
>  	if (op->cipher.iv.length == 12) {
> -		op->cipher.iv.data[15] = 1;
> +		uint32_t *iv_padd = (uint32_t *)&op->cipher.iv.data[12];
> +		*iv_padd = rte_bswap32(1);

Should not be that the last byte (number 15) always be set to 1?

>  	}
> 
>  	if (op->auth.aad.length != 12 && op->auth.aad.length != 8 &&
> --
> 2.1.0