> -----Original Message-----
> From: Kusztal, ArkadiuszX
> Sent: Friday, May 27, 2022 8:31 AM
> To: Anoob Joseph <ano...@marvell.com>; Akhil Goyal <gak...@marvell.com>;
> dev@dpdk.org; Kiran Kumar Kokkilagadda <kirankum...@marvell.com>
> Cc: Zhang, Roy Fan <roy.fan.zh...@intel.com>; Umesh Kartha
> <ukar...@marvell.com>; Ramkumar Balu <rb...@marvell.com>
> Subject: RE: [EXT] [PATCH 11/40] cryptodev: remove asym crypto next xform
>
> Hi Anoob,
>
> Sorry, I don't know how I have missed this email!
>
> > -----Original Message-----
> > From: Anoob Joseph <ano...@marvell.com>
> > Sent: Wednesday, May 25, 2022 9:06 AM
> > To: Kusztal, ArkadiuszX <arkadiuszx.kusz...@intel.com>; Akhil Goyal
> > <gak...@marvell.com>; dev@dpdk.org; Kiran Kumar Kokkilagadda
> > <kirankum...@marvell.com>
> > Cc: Zhang, Roy Fan <roy.fan.zh...@intel.com>; Umesh Kartha
> > <ukar...@marvell.com>; Ramkumar Balu <rb...@marvell.com>
> > Subject: RE: [EXT] [PATCH 11/40] cryptodev: remove asym crypto next
> > xform
> >
> > Hi Arek, Akhil,
> >
> > Please see inline.
> >
> > Thanks,
> > Anoob
> >
> > > -----Original Message-----
> > > From: Kusztal, ArkadiuszX <arkadiuszx.kusz...@intel.com>
> > > Sent: Wednesday, May 25, 2022 12:06 PM
> > > To: Akhil Goyal <gak...@marvell.com>; dev@dpdk.org; Kiran Kumar
> > > Kokkilagadda <kirankum...@marvell.com>; Anoob Joseph
> > > <ano...@marvell.com>
> > > Cc: Zhang, Roy Fan <roy.fan.zh...@intel.com>
> > > Subject: RE: [EXT] [PATCH 11/40] cryptodev: remove asym crypto next
> > > xform
> > >
> > >
> > >
> > > > -----Original Message-----
> > > > From: Akhil Goyal <gak...@marvell.com>
> > > > Sent: Wednesday, May 25, 2022 8:06 AM
> > > > To: Kusztal, ArkadiuszX <arkadiuszx.kusz...@intel.com>;
> > > > dev@dpdk.org; Kiran Kumar Kokkilagadda <kirankum...@marvell.com>;
> > > > Anoob Joseph <ano...@marvell.com>
> > > > Cc: Zhang, Roy Fan <roy.fan.zh...@intel.com>
> > > > Subject: RE: [EXT] [PATCH 11/40] cryptodev: remove asym crypto
> > > > next xform
> > > >
> > > > > > > - removed asymnetric crypto xform next field.
> > > > > > > Rationale behind having chaining in symmetric crypto was a
> > > > > > > fact that encryption and authentication are usually done on
> > > > > > > the same set of data independent of algorithm.
> > > > > > > HW usually will be able to handle it in one PCI call.
> > > > > > > In asymmetric there is no such relation between algorithms,
> > > > > > > therefore next field would be useless.
> > > > > > >
> > > > > > > Signed-off-by: Arek Kusztal <arkadiuszx.kusz...@intel.com>
> > > > > >
> > > > > > Please check documentation
> "doc/guides/prog_guide/cryptodev_lib.rst"
> > > > > > Not all asymmetric crypto xforms are supported for chaining.
> > > > > > Currently supported asymmetric crypto chaining is
> > > > > > Diffie-Hellman private key generation followed by public generation.
> > > > > [Arek] And why do chaining when this can be done even with one bit
> > > > > flag.
> > > > >
> > > > I believe it is OK to remove next. @Kiran Kumar Kokkilagadda/Anoob
> > > > please confirm.
> > > >
> > > > If we are removing it, then documentation should be in sync.
> > > [Arek] - although, we may keep it for now, I am not dropping it in v2.
> > > DH priv + pub can be done with priv_key.len = 0 -> similar as 'k' in
> > > ecdsa when k.data = NULL.
> > > But I do not see any situation for now it will be useful, it may be
> > > dropped later if not application found.
> > > >
> > > > > Also, currently API does not support chaining of
> > > > > > symmetric and asymmetric crypto xforms.
> > > > > [Arek] - This is one unlikely scenario to combine symmetric and
> > > > > asymmetric. One I can think of was once proposed DH + DSA
> > > > > integration for random number. But not much else, although we
> > > > > can keep it around for a
> > > > while.
> > > >
> > > > Yes it is highly unlikely to use this combination.
> >
> > [Anoob] We may need this support when we add EdDSA support. That would
> > involve a asymmetric operation after hash is generated (symmetric).
> > https://en.wikipedia.org/wiki/EdDSA#Ed25519
> >
> > And, asymmetric chaining may become useful when we have PMDs capable
> > of doing more operations together (like the case with EdDSA). So my
> > preference would be to retain the 'next' field in asym crypto xform.
> [Arek] - that is very good point, however to implement EdDSA as chaining would
> mean that:
> - we need to implement EdDSA internals in DPDK
> - and EdDSA (in hash option, where actually picking hash would have sense) is
> not one hash but multiple hash operation, so we would have to had multiple
> chaining with operations in between
> - and we would have to compute R and S separately.
> - If PMD does not support one-pass EdDSA - well this is something that should
> definitely discuss, but having any crypto internals in DPDK is not probably an
> option?
[Arek] - but, I have kept 'next' in later changes.
>
> >
> > > >
> > > > > >
> > > > > > > ---
> > > > > > > lib/cryptodev/rte_crypto_asym.h | 2 --
> > > > > > > 1 file changed, 2 deletions(-)
> > > > > > >
> > > > > > > diff --git a/lib/cryptodev/rte_crypto_asym.h
> > > > > > > b/lib/cryptodev/rte_crypto_asym.h index
> > > > > > > 1652a434a5..b355cbe5fa
> > > > > > > 100644
> > > > > > > --- a/lib/cryptodev/rte_crypto_asym.h
> > > > > > > +++ b/lib/cryptodev/rte_crypto_asym.h
> > > > > > > @@ -492,8 +492,6 @@ struct rte_crypto_ecpm_op_param {
> > > > > > > * Structure describing asym xforms.
> > > > > > > */
> > > > > > > struct rte_crypto_asym_xform {
> > > > > > > - struct rte_crypto_asym_xform *next;
> > > > > > > - /**< Pointer to next xform to set up xform chain.*/
> > > > > > > enum rte_crypto_asym_xform_type xform_type;
> > > > > > > /**< Asymmetric crypto transform */
> > > > > > >
> > > > > > > --
> > > > > > > 2.13.6
