Thanks for the clarification.  I guess I need to go back and figure out how ZFS 
crypto keying is performed.  I guess most likely the key is generated from some 
sort of one-way hash from a passphrase?

  - Garrett

-----Original Message-----
From: Darren J Moffat [mailto:darren.mof...@oracle.com]
Sent: Thu 12/23/2010 1:32 AM
To: Garrett D'Amore
Cc: Erik Trimble; Jerry Kemp; zfs-discuss@opensolaris.org
Subject: Re: [zfs-discuss] stupid ZFS question - floating point operations
 
On 22/12/2010 20:27, Garrett D'Amore wrote:
> That said, some operations -- and cryptographic ones in particular --
> may use floating point registers and operations because for some
> architectures (sun4u rings a bell) this can make certain expensive

Well remembered!  There are sun4u optimisations that use the floating 
point unit but those only apply to the bignum code which in kernel is 
only used by RSA.

> operations go faster. I don't think this is the case for secure
> hash/message digest algorithms, but if you use ZFS encryption as found
> in Solaris 11 Express you might find that on certain systems these
> registers are used for performance reasons, either on the bulk crypto or
> on the keying operations. (More likely the latter, but my memory of
> these optimizations is still hazy.)

RSA isn't used at all by ZFS encryption, everything is AES (including 
key wrapping) and SHA256.

So those optimistations for floating point don't come into play for ZFS 
encryption.

-- 
Darren J Moffat

_______________________________________________
zfs-discuss mailing list
zfs-discuss@opensolaris.org
http://mail.opensolaris.org/mailman/listinfo/zfs-discuss

Reply via email to