Re: [dpdk-dev] [PATCH] cryptodev: fix SHA-1 digest enum comment

["Dybkowski, AdamX" <adamx.dybkowski@intel.com>]

Hi.
My answer below.

Adam

> -----Original Message-----
> From: Anoob Joseph <anoobj@marvell.com>
> Sent: Tuesday, 19 May, 2020 07:54
> To: Dybkowski, AdamX <adamx.dybkowski@intel.com>; dev@dpdk.org;
> Trahe, Fiona <fiona.trahe@intel.com>; akhil.goyal@nxp.com
> Cc: stable@dpdk.org
> Subject: RE: [dpdk-dev] [PATCH] cryptodev: fix SHA-1 digest enum comment
> 
> Hi Adam, Akhil,
> 
> Please see inline.
> 
> Thanks,
> Anoob
> 
> > -----Original Message-----
> > From: dev <dev-bounces@dpdk.org> On Behalf Of Adam Dybkowski
> > Sent: Monday, May 18, 2020 7:54 PM
> > To: dev@dpdk.org; fiona.trahe@intel.com; akhil.goyal@nxp.com
> > Cc: Adam Dybkowski <adamx.dybkowski@intel.com>; stable@dpdk.org
> > Subject: [dpdk-dev] [PATCH] cryptodev: fix SHA-1 digest enum comment
> >
> > This patch fixes improper SHA-1 digest size in the enum comment.
> >
> > Fixes: 1bd407fac80b ("cryptodev: extract symmetric operations")
> > Cc: stable@dpdk.org
> >
> > Signed-off-by: Adam Dybkowski <adamx.dybkowski@intel.com>
> > ---
> >  lib/librte_cryptodev/rte_crypto_sym.h | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/lib/librte_cryptodev/rte_crypto_sym.h
> > b/lib/librte_cryptodev/rte_crypto_sym.h
> > index d9585ecd6..9cea4e5f0 100644
> > --- a/lib/librte_cryptodev/rte_crypto_sym.h
> > +++ b/lib/librte_cryptodev/rte_crypto_sym.h
> > @@ -269,9 +269,9 @@ enum rte_crypto_auth_algorithm {
> >  	/**< HMAC using MD5 algorithm */
> >
> >  	RTE_CRYPTO_AUTH_SHA1,
> > -	/**< 128 bit SHA algorithm. */
> > +	/**< 160 bit SHA algorithm. */
> >  	RTE_CRYPTO_AUTH_SHA1_HMAC,
> > -	/**< HMAC using 128 bit SHA algorithm. */
> > +	/**< HMAC using 160 bit SHA algorithm. */
> 
> [Anoob] This raises one interesting question. Is HMAC-SHA-1-96
> (https://tools.ietf.org/html/rfc2404) treated as a separate algorithm or is it a
> digest size variant of RTE_CRYPTO_AUTH_SHA1_HMAC? I assume the later.

[Adam] DPDK doesn't have separate enums for such variations. According to RFC 2104, chapter "5. Truncated output", the calculation of HMAC-SHA-1-96 is done using ordinary HMAC-SHA-1, but the calculation result is then truncated to 96 bits, or any other digest size provided in auth xform.

> 
> >  	RTE_CRYPTO_AUTH_SHA224,
> >  	/**< 224 bit SHA algorithm. */
> >  	RTE_CRYPTO_AUTH_SHA224_HMAC,
> > --
> > 2.17.1