linux-kernel - Re: [CRYPTO] is it really optimized ?

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 17 Apr 2007 09:33:21 -0700
From:	Roland Dreier <rdreier@...co.com>
To:	"Francis Moreau" <francis.moro@...il.com>
Cc:	"Herbert Xu" <herbert@...dor.apana.org.au>,
	helge.hafting@...el.hist.no, linux-kernel@...r.kernel.org,
	linux-crypto@...r.kernel.org
Subject: Re: [CRYPTO] is it really optimized ?

 > > I wonder if there's some way you can cache the last caller and reload
 > > the key lazily (only when it changes).
 > 
 > yes something that allows crypto drivers to detect if the key has
 > changed would be good.

It seems trivial to keep the last key you were given and do a quick
memcmp in your setkey method to see if it's different from the last
key you pushed to hardware, and set a flag if it is.  Then only do
your set_key() if you have a new key to pass to hardware.

I'm assuming the expense is in the aes_write() calls, and you could
avoid them if you know you're not writing something new.

 - R.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/