Re: [dpdk-dev] [EXT] [PATCH v3 09/11] cryptodev: add RSA padding none description

[Shally Verma <shallyv@marvell.com>]

> -----Original Message-----
> From: Arek Kusztal <arkadiuszx.kusztal@intel.com>
> Sent: Wednesday, July 17, 2019 12:23 AM
> To: dev@dpdk.org
> Cc: akhil.goyal@nxp.com; fiona.trahe@intel.com; Shally Verma
> <shallyv@marvell.com>; Arek Kusztal <arkadiuszx.kusztal@intel.com>
> Subject: [EXT] [PATCH v3 09/11] cryptodev: add RSA padding none
> description
> 
> External Email
> 
> ----------------------------------------------------------------------
> This patch adds RSA padding none description.
> 
> Signed-off-by: Arek Kusztal <arkadiuszx.kusztal@intel.com>
> ---
>  lib/librte_cryptodev/rte_crypto_asym.h | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/librte_cryptodev/rte_crypto_asym.h
> b/lib/librte_cryptodev/rte_crypto_asym.h
> index 5026042..7f630f0 100644
> --- a/lib/librte_cryptodev/rte_crypto_asym.h
> +++ b/lib/librte_cryptodev/rte_crypto_asym.h
> @@ -90,7 +90,10 @@ enum rte_crypto_asym_xform_type {
>   */
>  enum rte_crypto_asym_op_type {
>  	RTE_CRYPTO_ASYM_OP_ENCRYPT,
> -	/**< Asymmetric Encrypt operation */
> +	/**< RSA no padding scheme.
> +	 * In this case user is responsible for provision and verification
> +	 * of padding.
> +	 */
>  	RTE_CRYPTO_ASYM_OP_DECRYPT,
>  	/**< Asymmetric Decrypt operation */
>  	RTE_CRYPTO_ASYM_OP_SIGN,
> @@ -409,6 +412,11 @@ struct rte_crypto_rsa_op_param {
>  	 * - padding PSS
>  	 * data provided should contain message digest of the message
>  	 * to be signed
> +	 *
> +	 * When padding field is set to RTE_CRYPTO_RSA_PADDING_NONE
> +	 * and RTE_CRYPTO_ASYM_OP_DECRYPT op_type used returned
> data size
> +	 * will be equal to the size of RSA key in bytes. All leading
> +	 * zeroes will be preserved.
[Shally] its bit unclear here. So, app is supposed to pass buffer with padding removed or padding intact? Are leading 0's padding bytes?
If so, I believe app can use any kind of padding, BT2 or OAEP so it does not have to be necessarily 0. Or
May be I am missing some info here. Could you point me to source which says, for padding none, data will always be padded with leading 0s?

>  	 */
> 
> 
> --
> 2.1.0