Re: [Ocf-linux-users] A quick question about cryptodev openssl engine.

[Liu H. <onl...@gm...>]

Hi David,

Got it, thanks for your opinion.

Much appreciated!
Hui

2011/7/30 David McCullough <dav...@mc...>

>
> Jivin Liu Hui lays it down ...
> > Hi David and all.
> >
> > I take a loot at the source code of cryptodev openssl engine and have one
> question.
> >
> > OCF-Linux has a good framework for IPSEC combination request,
> > for example, if 3des+sha1 comes, ocf-driver can handle them in one
> operation.
> > So some hardware which support combination request, this is very
> convenient because they don't have to do the request for two times. And it
> also save a lot time for memory copy.
> >
> > But openssl engine mechanism seems to can't handle combination request,
> they only can pass
> > crypt and hash request separately to the cryptodev.  So,  driver and
> hardware have to operate twice instead of one.
> >
> > Is this a restrict of OPENSSL engine mechanism? If so, the cryptodev
> engine have to follow this restrict. Am I right?
>
> This is a restiction of how the openssl engine is implemented.
> I believe cryptodev will allow conbinations just like the kernel, you can
> try it by modifying cryptotest and see.
>
> > And I don't understand, why the famous OPENSSL doesn't consider the
> combination request in its engine mechanism? This is very important for
> performance.
>
> You will notice that by default openssl doesn't even do hashes,  you need
> to
> enable it specifically with a config option.
>
> You are right though,  if you wanted to do both cipher and hash,  then
> having cryptodev do both at the same time would be great.  I am not sure
> the
> openssl internals are geared up for that though.
>
> If you can figure it out then I am sure the openssl devs would be happy to
> take a patch.
>
> If, however,  you just want to do cipher+hash in another program,  then
> just
> go ahead and do it using cryptodev directly.  if you hit any issues I'll be
> glad to fix them or sort it out.
>
> Cheers,
> Davidm
>
> --
> David McCullough,      dav...@mc...,  Ph:+61 734352815
> McAfee - SnapGear      http://www.mcafee.com         http://www.uCdot.org
>



-- 
Thanks & Best Regards
Liu Hui
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