Re: [dpdk-dev] [PATCH] cryptodev: add an option to support both iv and J0 for GCM

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

Hi Fiona,

> [Fiona] IVs greater than 16 bytes can be used, right? If so change to "a minimum of 16 bytes must be >allocated". Same below.

[AK] - yes, this comment may be misleading, of course it means 16 bytes minimum. This is because of legacy reasons, i.e. aesni-gcm once had formation of pre-counter block inside the PMD using the existing buffer (when len(iv)==12), hence need for 16 bytes allocation. Some other drivers still can behave in similar fashion so it probably has to stay for a while.
I will send v2.

> -----Original Message-----
> From: Trahe, Fiona
> Sent: Wednesday, April 17, 2019 1:38 PM
> To: Kusztal, ArkadiuszX <arkadiuszx.kusztal@intel.com>; dev@dpdk.org
> Cc: akhil.goyal@nxp.com; De Lara Guarch, Pablo
> <pablo.de.lara.guarch@intel.com>; Trahe, Fiona <fiona.trahe@intel.com>
> Subject: RE: [PATCH] cryptodev: add an option to support both iv and J0 for
> GCM
> 
> Hi Arek,
> 
> > -----Original Message-----
> > From: Kusztal, ArkadiuszX
> > Sent: Wednesday, April 17, 2019 8:37 AM
> > To: dev@dpdk.org
> > Cc: akhil.goyal@nxp.com; Trahe, Fiona <fiona.trahe@intel.com>; De Lara
> > Guarch, Pablo <pablo.de.lara.guarch@intel.com>; Kusztal, ArkadiuszX
> > <arkadiuszx.kusztal@intel.com>
> > Subject: [PATCH] cryptodev: add an option to support both iv and J0
> > for GCM
> >
> > This patch adds an option to support both IV (of all supported sizes)
> > and J0 when using Galois Counter Mode of crypto operation.
> >
> > Signed-off-by: Arek Kusztal <arkadiuszx.kusztal@intel.com>
> > ---
> >  lib/librte_cryptodev/rte_crypto_sym.h | 37
> > ++++++++++++++++++-----------------
> >  1 file changed, 19 insertions(+), 18 deletions(-)
> >
> > diff --git a/lib/librte_cryptodev/rte_crypto_sym.h
> > b/lib/librte_cryptodev/rte_crypto_sym.h
> > index c80e90e..126d9f3 100644
> > --- a/lib/librte_cryptodev/rte_crypto_sym.h
> > +++ b/lib/librte_cryptodev/rte_crypto_sym.h
> > @@ -152,11 +152,6 @@ struct rte_crypto_cipher_xform {
> >  		 *
> >  		 * - For block ciphers in CTR mode, this is the counter.
> >  		 *
> > -		 * - For GCM mode, this is either the IV (if the length
> > -		 * is 96 bits) or J0 (for other sizes), where J0 is as
> > -		 * defined by NIST SP800-38D. Regardless of the IV
> > -		 * length, a full 16 bytes needs to be allocated.
> > -		 *
> >  		 * - For CCM mode, the first byte is reserved, and the
> >  		 * nonce should be written starting at &iv[1] (to allow
> >  		 * space for the implementation to write in the flags @@ -
> 184,9
> > +179,6 @@ struct rte_crypto_cipher_xform {
> >  		 * of the counter (which must be the same as the block
> >  		 * length of the cipher).
> >  		 *
> > -		 * - For GCM mode, this is either 12 (for 96-bit IVs)
> > -		 * or 16, in which case data points to J0.
> > -		 *
> >  		 * - For CCM mode, this is the length of the nonce,
> >  		 * which can be in the range 7 to 13 inclusive.
> >  		 */
> > @@ -306,9 +298,10 @@ struct rte_crypto_auth_xform {
> >  		 * specified as number of bytes from start of crypto
> >  		 * operation (rte_crypto_op).
> >  		 *
> > -		 * - For SNOW 3G in UIA2 mode, for ZUC in EIA3 mode and
> > -		 *   for AES-GMAC, this is the authentication
> > -		 *   Initialisation Vector (IV) value.
> > +		 * - For SNOW 3G in UIA2 mode, for ZUC in EIA3 mode
> > +		 *   this is the authentication Initialisation Vector
> > +		 *   (IV) value. For AES-GMAC IV description please refer
> > +		 *   to the field `length` in iv struct.
> >  		 *
> >  		 * - For KASUMI in F9 mode and other authentication
> >  		 *   algorithms, this field is not used.
> > @@ -325,6 +318,14 @@ struct rte_crypto_auth_xform {
> >  		 * - For KASUMI in F9 mode and other authentication
> >  		 *   algorithms, this field is not used.
> >  		 *
> > +		 * - For GMAC mode, this is either:
> > +		 * 1) Number greater or equal to one, which means that IV
> > +		 *    is used and J0 will be computed internally, 16 bytes
> > +		 *    needs to be allocated.
> [Fiona] IVs greater than 16 bytes can be used, right? If so change to "a
> minimum of 16 bytes must be allocated". Same below.
> 
> > +		 * 2) Zero, in which case data points to J0. In this case
> > +		 *    16 bytes of J0 should be passed where J0 is defined
> > +		 *    by NIST SP800-38D.
> > +		 *
> >  		 */
> >  	} iv;	/**< Initialisation vector parameters */
> >
> > @@ -383,11 +384,6 @@ struct rte_crypto_aead_xform {
> >  		 * specified as number of bytes from start of crypto
> >  		 * operation (rte_crypto_op).
> >  		 *
> > -		 * - For GCM mode, this is either the IV (if the length
> > -		 * is 96 bits) or J0 (for other sizes), where J0 is as
> > -		 * defined by NIST SP800-38D. Regardless of the IV
> > -		 * length, a full 16 bytes needs to be allocated.
> > -		 *
> >  		 * - For CCM mode, the first byte is reserved, and the
> >  		 * nonce should be written starting at &iv[1] (to allow
> >  		 * space for the implementation to write in the flags @@ -
> 401,8
> > +397,13 @@ struct rte_crypto_aead_xform {
> >  		uint16_t length;
> >  		/**< Length of valid IV data.
> >  		 *
> > -		 * - For GCM mode, this is either 12 (for 96-bit IVs)
> > -		 * or 16, in which case data points to J0.
> > +		 * - For GCM mode, this is either:
> > +		 * 1) Number greater or equal to one, which means that IV
> > +		 *    is used and J0 will be computed internally, 16 bytes
> > +		 *    needs to be allocated.
> > +		 * 2) Zero, in which case data points to J0. In this case
> > +		 *    16 bytes of J0 should be passed where J0 is defined
> > +		 *    by NIST SP800-38D.
> >  		 *
> >  		 * - For CCM mode, this is the length of the nonce,
> >  		 * which can be in the range 7 to 13 inclusive.
> > --
> > 2.1.0