Openwall GNU/*/Linux - a small security-enhanced Linux distro for servers
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Fri, 16 Mar 2012 09:32:21 +0100
From: magnum <john.magnum@...hmail.com>
To: john-dev@...ts.openwall.com
Subject: Re: OpenSSL and AES-NI (was: RAR format finally proper)

On 03/13/2012 02:13 AM, magnum wrote:
> On 03/07/2012 11:37 PM, magnum wrote:
>> On 03/06/2012 08:11 AM, Milen Rangelov wrote:
>>> As per AES/OpenSSL, I read somewhere they implemented runtime AES-NI
>>> detection/use. Though I don't think this have made it into the debian
>>> packages I use yet. It might improve things a lot.
>>
>> Yeah interesting, it can decrypt a byte in 2 cycles instead of 15... I
>> suppose you could try using the code supplied by Intel at the end of
>> this PDF: http://software.intel.com/file/24917 - it even mimics the
>> OpenSSL interfaces.
> 
> It seems my standard Ubuntu OpenSSL 1.0.0e has AES-NI configured and
> enabled out of the box so maybe this is nothing to worry about? I'll
> benchmark it later on a CPU that actually supports it.
> 
> Anyway here's a better "version" (the one above is source code in PDF
> form) of that Intel library, if we ever need one:
> http://software.intel.com/en-us/articles/download-the-intel-aesni-sample-library/

I did some experiments. Linking the Intel lib (referenced above) to the
RAR format, I get a significant speedup compared to OpenSSL (despite
I'm still running the key/iv generation in CPU - using OpenCL the boost
will be even better). But when I run this:

$ openssl speed -engine aesni -decrypt -evp aes-128-cbc

On an Intel(R) Core(TM)2 Duo CPU     P8600  @ 2.40GHz (lacking aesni):

type             16 bytes     64 bytes    256 bytes   1024 bytes   8192
bytes
aes-128-cbc      50781.48k    56127.74k    57736.73k   167606.27k
170622.98k


On an Intel(R) Core(TM) i7-2640M CPU @ 2.80GHz (with aesni):

type             16 bytes     64 bytes    256 bytes   1024 bytes   8192
bytes
aes-128-cbc     633410.88k  2060109.74k  2740870.85k  2959463.09k
3014486.13k


...this is 17x faster (both machines using exact same versions of
everything) so it clearly shows that OpenSSL *can* use AES-NI.

So I suspect the current OpenSSL use in RAR format just fails to
"enable" AES-NI until we modify it a little. Some googling indicates we
might have to use the EVP interface in order to get AES-NI from OpenSSL.
I have still to get that working (I find it backwards that the high
level interface is much more complicated to use than the low level ones)
and I suspect this will be slower than the Intel lib anyway because of
much more overhead.

magnum

Powered by blists - more mailing lists

Your e-mail address:

Powered by Openwall GNU/*/Linux - Powered by OpenVZ