Re: [dpdk-dev] [PATCH v2 1/3] cryptodev: rework api of rsa algorithm

["Kusztal, ArkadiuszX" <arkadiuszx.kusztal@intel.com>]

To clarify bit more
With [AK2]

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Kusztal, ArkadiuszX
> Sent: Monday, July 8, 2019 7:44 PM
> To: Shally Verma <shallyv@marvell.com>; dev@dpdk.org
> Cc: akhil.goyal@nxp.com; Trahe, Fiona <fiona.trahe@intel.com>;
> shally.verma@caviumnetworks.com
> Subject: Re: [dpdk-dev] [PATCH v2 1/3] cryptodev: rework api of rsa
> algorithm
> 
> Hi Shally,
> 
> With [AK]
> 
> > -----Original Message-----
> > From: Shally Verma [mailto:shallyv@marvell.com]
> > Sent: Saturday, July 6, 2019 3:14 PM
> > To: Kusztal, ArkadiuszX <arkadiuszx.kusztal@intel.com>; dev@dpdk.org
> > Cc: akhil.goyal@nxp.com; Trahe, Fiona <fiona.trahe@intel.com>;
> > shally.verma@caviumnetworks.com
> > Subject: RE: [PATCH v2 1/3] cryptodev: rework api of rsa algorithm
> >
> >
> >
> > > -----Original Message-----
> > > From: Kusztal, ArkadiuszX <arkadiuszx.kusztal@intel.com>
> > > Sent: Thursday, July 4, 2019 6:10 PM
> > > To: dev@dpdk.org
> > > Cc: akhil.goyal@nxp.com; Trahe, Fiona <fiona.trahe@intel.com>;
> > > shally.verma@caviumnetworks.com; Shally Verma
> <shallyv@marvell.com>
> > > Subject: [EXT] RE: [PATCH v2 1/3] cryptodev: rework api of rsa
> > > algorithm
> > >
> > > External Email
> > >
> > ..
> >
> > > > diff --git a/lib/librte_cryptodev/rte_crypto_asym.h
> > > > b/lib/librte_cryptodev/rte_crypto_asym.h
> > > > index 8672f21..486399c 100644
> > > > --- a/lib/librte_cryptodev/rte_crypto_asym.h
> > > > +++ b/lib/librte_cryptodev/rte_crypto_asym.h
> > > > @@ -111,23 +111,21 @@ enum rte_crypto_asym_op_type {
> > > >   */
> > > >  enum rte_crypto_rsa_padding_type {
> > > >  	RTE_CRYPTO_RSA_PADDING_NONE = 0,
> > > > -	/**< RSA no padding scheme */
> > > > -	RTE_CRYPTO_RSA_PKCS1_V1_5_BT0,
> > > > -	/**< RSA PKCS#1 V1.5 Block Type 0 padding scheme
> > > > -	 * as described in rfc2313
> > > > +	/**< RSA no padding scheme.
> > > > +	 * In this case user is responsible for provision and verification
> > > > +	 * of padding.
> > > >  	 */
> > > > -	RTE_CRYPTO_RSA_PKCS1_V1_5_BT1,
> > > > -	/**< RSA PKCS#1 V1.5 Block Type 01 padding scheme
> > > > -	 * as described in rfc2313
> > > > -	 */
> > > > -	RTE_CRYPTO_RSA_PKCS1_V1_5_BT2,
> > > > -	/**< RSA PKCS#1 V1.5 Block Type 02 padding scheme
> > > > -	 * as described in rfc2313
> > > > +	RTE_CRYPTO_RSA_PADDING_PKCS1,
> > [Shally] My preference would still be to rename as PKCS1_V1.5 to align
> > more to standard
> [AK] - Agree.
> 
> >
> > > > +	/**< RSA PKCS#1 PKCS1-v1_5 padding scheme. For signatures block
> > > > type 01,
> > > > +	 * for encryption block type 02 are used.
> > > >  	 */
> > > >  	RTE_CRYPTO_RSA_PADDING_OAEP,
> > > > -	/**< RSA PKCS#1 OAEP padding scheme */
> > > > +	/**< RSA PKCS#1 OAEP padding scheme, can be used only for
> > > > encryption/
> > > > +	 * decryption.
> > > > +	 */
> > > >  	RTE_CRYPTO_RSA_PADDING_PSS,
> > > > -	/**< RSA PKCS#1 PSS padding scheme */
> > > > +	/**< RSA PKCS#1 PSS padding scheme, can be used only for
> > > > signatures.
> > > > +	 */
> > > >  	RTE_CRYPTO_RSA_PADDING_TYPE_LIST_END
> > > >  };
> > > >
> > ...
> >
> > > >  struct rte_crypto_rsa_xform {
> > > >  	rte_crypto_param n;
> > > > -	/**< n - Prime modulus
> > > > -	 * Prime modulus data of RSA operation in Octet-string network
> > > > +	/**< n - Modulus
> > > > +	 * Modulus data of RSA operation in Octet-string network
> > > >  	 * byte order format.
> > > >  	 */
> > > >
> > > > @@ -397,9 +395,36 @@ struct rte_crypto_rsa_op_param {
> > > >  	/**<
> > > >  	 * Pointer to data
> > > >  	 * - to be encrypted for RSA public encrypt.
> > > > -	 * - to be decrypted for RSA private decrypt.
> > > >  	 * - to be signed for RSA sign generation.
> > > >  	 * - to be authenticated for RSA sign verification.
> > > > +	 *
> > > > +	 * Octet-string network byte order format.
> > > > +	 *
> > > > +	 * This field is an input to RTE_CRYPTO_ASYM_OP_ENCRYPT
> > > > +	 * operation, and output to RTE_CRYPTO_ASYM_OP_DECRYPT
> > > > operation.
> > > > +	 *
> > > > +	 * When RTE_CRYPTO_ASYM_OP_DECRYPT op_type used length in
> > > > bytes
> > > > +	 * of this field needs to be greater or equal to the length of
> > > > +	 * corresponding RSA key in bytes.
> > [Shally] better rephrased " When an op_type ASYM_OP_DECRYPT used,
> > length of output buffer should be greater than  or equal to RSA key
> > modulus length
> [AK] - RSA key size is a RSA modulus size, but can be changed.
> >
> > > > +	 *
> > > > +	 * When padding field is set to RTE_CRYPTO_RSA_PADDING_NONE
> > > > +	 * returned data size will be equal to the size of RSA key
> > > > +	 * in bytes. All leading zeroes will be preserved.
> > > > +	 */
> > [Shally] Is it in context of OP_TYPE_DECRYPT? Even if it is
> > PADDING_NONE, whether it is encrypted/decrypted, o/p length can vary
> > between 0 .. RSA modulus length - 1 as perf rfc8017
> [AK]
> example. 20 bytes was encrypted with 2048bit key PKCS_1.5 1. Padding
> PKCS_1.5 set - Upon decryption we return 20 bytes of recovered message.
> 2. Padding NONE set (padding done by user) - we return 236 bytes of padding
> (one leading zero) | 20 bytes of message = 256 bytes.
> (like in example test case I have added) 3. Padding NONE set (textbook rsa) -
> we return 236 bytes of zeroes | 20 bytes of message = 256 bytes.
> >
> > > > +
> > > > +	rte_crypto_param cipher;
> > > > +	/**<
> > > > +	 * Pointer to data
> > > > +	 * - to be decrypted for RSA private decrypt.
> > > > +	 *
> > > > +	 * Octet-string network byte order format.
> > > > +	 *
> > > > +	 * This field is an input to RTE_CRYPTO_ASYM_OP_DECRYPT
> > > > +	 * operation, and output to RTE_CRYPTO_ASYM_OP_ENCRYPT
> > > > operation.
> > > > +	 *
> > > > +	 * When RTE_CRYPTO_ASYM_OP_ENCRYPT op_type used length in
> > > > bytes
> > > > +	 * of this field needs to be greater or equal to the length of
> > > > +	 * corresponding RSA key in bytes.
> > > >  	 */
> > [Shally] recommend rephrasing as above
> >
> > > >
> > > >  	rte_crypto_param sign;
> > > > @@ -408,27 +433,88 @@ struct rte_crypto_rsa_op_param {
> > > >  	 * sign @ref RTE_CRYPTO_ASYM_OP_SIGN, buffer will be
> > > >  	 * over-written with generated signature.
> > > >  	 *
> > > > -	 * Length of the signature data will be equal to the
> > > > -	 * RSA prime modulus length.
> > > > +	 * Octet-string network byte order format.
> > > > +	 *
> > > > +	 * When RTE_CRYPTO_ASYM_OP_SIGN op_type used length in bytes
> > > > +	 * of this field needs to be greater or equal to the length of
> > > > +	 * corresponding RSA key in bytes.
> > [Shally] field ---> buffer
> [AK] - Agreed
> >
> > > >  	 */
> > > >
> > > > -	enum rte_crypto_rsa_padding_type pad;
> > > > -	/**< RSA padding scheme to be used for transform */
> > > > -
> > > > -	enum rte_crypto_auth_algorithm md;
> > > > -	/**< Hash algorithm to be used for data hash if padding
> > > > -	 * scheme is either OAEP or PSS. Valid hash algorithms
> > > > -	 * are:
> > > > -	 * MD5, SHA1, SHA224, SHA256, SHA384, SHA512
> > > > +	rte_crypto_param message_to_verify;
> > > > +	/**<
> > > > +	 * Pointer to the message 'm' that was signed with
> > > > +	 * RSASP1 in RFC8017.
> > >> It is the result of operation RSAVP1
> > > > +	 * defined in RFC8017, where field `sign` is the input
> > > > +	 * parameter `s`.
> > > > +	 *
> > [Shally] This is confusing. Are you trying to say "this is output to VERIFY_OP
> ?
> > where output should be same as message buffer provided above?
> > If yes, then why not just use that message buffer as an output of
> > VERIFY_OP than adding a new one?
> [AK] - it is output of signature verify (in openssl Public_Decrypt) for
> PADDING_NONE case. It will be used to check if signature is correct.
> In `message` then there could be original message.
> But yes, we can use message as an output buffer, I just though it would be
> more transparent.
> Since user need to verify it by himself it is not that important to keep original
> message in `message` field, both ways will do.
> Waiting for opinions.
> >
> > > > +	 * Used only when padding type is set to
> > > > RTE_CRYPTO_RSA_PADDING_NONE
> > [Shally] I think regardless of padding, we can provide it as output to
> > sign operation
> [AK] - `Sign` is the place to put signature into.
> >
> > > > +	 * and `op_type` is set to RTE_CRYPTO_ASYM_OP_VERIFY.
> > > > +	 *
> > > > +	 * Returned data size will be equal to the size of RSA key
> > > > +	 * in bytes. All leading zeroes will be preserved.
> > > > +	 *
> > [Shally] Again, I think it should instead be mentioned as return size
> > can be 0 ... modulus_len - 1
> >
> > > > +	 * When RTE_CRYPTO_ASYM_OP_VERIFY op_type used length in
> > > > bytes
> > > > +	 * of this field needs to be greater or equal to the length of
> > > > +	 * corresponding RSA key in bytes.
> > > >  	 */
> > [Shally] There're multiple statements starting with when op_type =
> > VERIFY, can we club them and make description shorter?
> >
> > > >
> > > > -	enum rte_crypto_auth_algorithm mgf1md;
> > > > +	enum rte_crypto_rsa_padding_type padding;
> > > > +	/**<
> > > > +	 * In case RTE_CRYPTO_RSA_PADDING_PKCS1 is selected,
> > > > +	 * driver will distinguish between block type basing
> > > > +	 * on rte_crypto_asym_op_type of the operation.
> > > > +	 *
> > > > +	 * Which padding type is supported by the driver can be
> > > > +	 * found in in specific driver guide.
> > [Shally] better rephrase " PMD expose padding type support in its
> capability.
> > Refer to <struct / API definition>
> >
> > > > +	 */
> > > > +	enum rte_crypto_auth_algorithm padding_hash;
> > > > +	/**<
> > > > +	 * -	For PKCS1-v1_5 signature (Block type 01) this field
> > > > +	 * represents hash function that will be used to create
> > > > +	 * message hash.
> > [Shally] Currently PMD input pre-computed hash atleast for PKCSV_1.5 ..
> > does your hw support this offload for RSA?
> > So far , in our testing we observe openssl does it already before
> > calling private/public_key_enc so we should not be mentioning it in
> > spec unless any hw provide that combined offload hash + rsa
> 
> [AK] - Openssl for PKCS1_5 signature use RSA_private_encrypt which does
> not handle algorithmIdentifier.
> https://www.openssl.org/docs/man1.0.2/man3/RSA_private_encrypt.html
> And it is not said what data should be provided for signing. To be properly
> signed input buffer should be DER encoded concatenation of
> algorithmIdentifier and message digest.
> There would be much work to be done by user then: adding OID, computing
> Hash of message, ASN.1 call. Waiting for comments on that.

[AK2] - we do not specify what data should user provide to be signed.

> 
> >
> > > > +	 *
> > > > +	 * -	For OAEP this field represents hash function that will
> > > > +	 * be used to produce hash of the optional label.
> > > > +	 *
> > > > +	 * -	For PSS this field represents hash function that will be used
> > > > +	 * to produce hash (mHash) of message M and of M' (padding1 |
> > > > mHash | salt)
> > > > +	 *
> > > > +	 * If not set driver will use default value.
> > > > +	 */
> > > > +	union {
> > > > +		struct {
> > > > +			enum rte_crypto_auth_algorithm mgf;
> > > > +			/**<
> > > > +			 * Mask genereation function hash algorithm.
> > > > +			 *
> > > > +			 * If not set driver will use default value.
> > > > +			 */
> > > > +			rte_crypto_param label;
> > > > +			/**<
> > > > +			 * Optional label, if driver does not support
> > > > +			 * this option, optional label is just an empty string.
> > > > +			 */
> > > > +		} OAEP;
> > > > +		struct {
> > > > +			enum rte_crypto_auth_algorithm mgf;
> > [Shally] Though  it is mentioned in current spec, but I have similar
> > doubt here do we need to provide this offload in spec? I will use
> > terms from rfc8017 for further discussion.
> >   if we have any PMD whose HW provide full RSAES-OAEP offload i.e.
> > doing EME-OAEP followed by RSAEP, then it make sense to have it in
> > spec. But if we don't have any PMD example which support that full
> > offload, then we can redefine spec only to support RSAEP and omit md and
> mgf from spec.
> >
> [AK] - I thought to add PSS/OAEP to Openssl. Though OAEP and PSS for sure
> will be implemented having custom MGF is not that necessary. Waiting for
> opinions.

> 
> >
> >
> > > > +			/**<
> > > > +			 * Mask genereation function hash algorithm.
> > > > +			 *
> > > > +			 * If not set driver will use default value.
> > > > +			 */
> > > > +			int seed_len;
> > > > +			/**<
> > > > +			 * Intended seed length. Nagative number has
> > > special
> > > > +			 * value as follows:
> > > > +			 * -1 : seed len = length of output ot used hash
> > > > function
> > > > +			 * -2 : seed len is maximized
> > > > +			 */
> > > > +		} PSS;
> > > > +	};
> > > >  	/**<
> > > > -	 * Hash algorithm to be used for mask generation if
> > > > -	 * padding scheme is either OAEP or PSS. If padding
> > > > -	 * scheme is unspecified data hash algorithm is used
> > > > -	 * for mask generation. Valid hash algorithms are:
> > > > -	 * MD5, SHA1, SHA224, SHA256, SHA384, SHA512
> > > > +	 * Padding type of RSA crypto operation.
> > > > +	 * What are random number generator requirements and prequisites
> > > > +	 * can be found specific driver guide.
> > [Shally] I would suggest it to rephrase again " app should refer to
> > PMD guide to check for RNG requirement and other pre-requisites used
> > in hash generation.
> > However , this feedback is relevant if we are retaining full OAEP offload.
> >
> > > >  	 */
> > > >  };
> > > >
> > > > --
> > > > 2.1.0