RE: [EXT] [PATCH v2] cryptodev: add elliptic curve diffie hellman

[Akhil Goyal <gakhil@marvell.com>]

> This commit adds Elliptic Curve Diffie-Hellman option to Cryptodev.
> This could be achieved with EC point multiplication but:
> 1) Phase 1 of DH is used with EC generator, multiplication expect
> setting generator manually.
> 2) It will unify usage of DH.
> 3) Can be extended easily to support X25519 and X448.

It is not clear how adding ECDH option will achieve above three statements.

> 
> Signed-off-by: Arek Kusztal <arkadiuszx.kusztal@intel.com>
> ---
> v2:
> - added ecdh comments to operation types
> 
> Depends-on: series-22684 ("cryptodev: move dh type from xform to dh op")
> 
>  lib/cryptodev/rte_crypto_asym.h | 46 +++++++++++++++++++++++----------------
> --
>  1 file changed, 26 insertions(+), 20 deletions(-)
> 
> diff --git a/lib/cryptodev/rte_crypto_asym.h b/lib/cryptodev/rte_crypto_asym.h
> index 4697a7bc59..64d97ae054 100644
> --- a/lib/cryptodev/rte_crypto_asym.h
> +++ b/lib/cryptodev/rte_crypto_asym.h
> @@ -91,6 +91,8 @@ enum rte_crypto_asym_xform_type {
>  	/**< Elliptic Curve Digital Signature Algorithm
>  	 * Perform Signature Generation and Verification.
>  	 */
> +	RTE_CRYPTO_ASYM_XFORM_ECDH,
> +	/**< Elliptic Curve Diffie Hellman */

Can we add this after ECPM?

And we also need to remove the LIST_ENDs from Asym.

>  	RTE_CRYPTO_ASYM_XFORM_ECPM,
>  	/**< Elliptic Curve Point Multiplication */
>  	RTE_CRYPTO_ASYM_XFORM_TYPE_LIST_END
> @@ -112,9 +114,9 @@ enum rte_crypto_asym_op_type {
>  	RTE_CRYPTO_ASYM_OP_PRIVATE_KEY_GENERATE,
>  	/**< DH Private Key generation operation */
>  	RTE_CRYPTO_ASYM_OP_PUBLIC_KEY_GENERATE,
> -	/**< DH Public Key generation operation */
> +	/**< DH/ECDH Public Key generation operation */
>  	RTE_CRYPTO_ASYM_OP_SHARED_SECRET_COMPUTE,
> -	/**< DH Shared Secret compute operation */
> +	/**< DH/ECDH Shared Secret compute operation */
>  	RTE_CRYPTO_ASYM_OP_LIST_END
>  };
> 
> @@ -385,34 +387,38 @@ struct rte_crypto_rsa_op_param {
>  };
> 
>  /**
> - * Diffie-Hellman Operations params.
> + * Diffie-Hellman/Elliptic Curve Diffie-Hellman operation.
>   * @note:
>   */
>  struct rte_crypto_dh_op_param {
>  	enum rte_crypto_asym_op_type op_type;
>  	/**< Diffie-Hellman operation type */
> -	rte_crypto_uint pub_key;
> +	rte_crypto_param priv_key;
>  	/**<
> -	 * Output generated public key when op_type is
> -	 * DH PUB_KEY_GENERATION.
> -	 * Input peer public key when op_type is DH
> -	 * SHARED_SECRET_COMPUTATION
> -	 *
> +	 * Diffie-Hellman private part
> +	 * For DH and ECDH it is big-endian integer.
> +	 * Input for both phases of Diffie-Hellman
>  	 */
> -
> -	rte_crypto_uint priv_key;
> +	union {
> +		rte_crypto_uint pub_key;
> +		struct rte_crypto_ec_point pub_point;
> +	};
>  	/**<
> -	 * Output generated private key if op_type is
> -	 * DH PRIVATE_KEY_GENERATION
> -	 * Input when op_type is DH SHARED_SECRET_COMPUTATION.
> -	 *
> +	 * Diffie-Hellman public part
> +	 * For DH it is big-endian unsigned integer.
> +	 * For ECDH it is a point on the curve.
> +	 * Output for RTE_CRYPTO_ASYM_OP_PUBLIC_KEY_GENERATE
> +	 * Input for RTE_CRYPTO_ASYM_OP_SHARED_SECRET_COMPUTE
>  	 */
> -
> -	rte_crypto_uint shared_secret;
> +	union {
> +		rte_crypto_uint shared_secret;
> +		struct rte_crypto_ec_point shared_point;
> +	};
>  	/**<
> -	 * Output with calculated shared secret
> -	 * when dh op_type = SHARED_SECRET_COMPUTATION.
> -	 *
> +	 * Diffie-Hellman shared secret
> +	 * For DH it is big-endian unsigned integer.
> +	 * For ECDH it is a point on the curve.
> +	 * Output for RTE_CRYPTO_ASYM_OP_SHARED_SECRET_COMPUTE
>  	 */
>  };

There are 2 questions for this above change.
- why is the order of parameters change?
- The patch description does not describe this change. Could you separate out this change
And provide proper explanation to this change?