Re: sha1/botan stuff (was Re: [Monotone-devel] updates to net.venge.monotone.experiment.performance)

[Nathaniel Smith]

On Thu, Aug 10, 2006 at 02:03:13AM -0700, Eric Anderson wrote:
>  > I'm nervous about landing it on mainline, even as optional, because of
>  > the potential legal issues -- e.g., possibly debian would have to rip
>  > it out again before distributing our standard packages, etc. etc.
> 
> I don't believe there is any legal issue because the legal issues only
> kick in if debian (or other vendor) explicitly configures with
> --with-crypto; by default it won't configure with crypto, so it won't
> use any of that code; I couldn't imagine that a configured-out call to
> SHA1() would cause a legal problem.  

Ah, but they distribute source code as well... I dunno, maybe I could
be convinced eventually, it's just one of those things I'd rather
steer well clear of.

>  > [ x86 SHA1 is license encumbered ]
> 
> Bummer.  http://sourceforge.net/projects/beecrypt/ and
> http://www.lysator.liu.se/~nisse/lsh/ both seem to have some sort of
> assembler optimized x86 implementations and they are both LGPL.

I bow to your google skills!  I totally failed to find these.

But I'm... unconvinced.  On my box (a 3GHz P4, in case anyone cares),
with a tiny test program, g++ 4.0.4 -O2 on my code + whatever their
build systems wanted on other code, I get:

  mozilla                                  :  36.9 MiB/s
  openssl ("no-asm debian-i386")           :  56.5 MiB/s
  openssl ("no-asm debian-i386-i686/cmov") :  56.5 MiB/s
  botan                                    :  64.1 MiB/s
  beecrypt (from debian)                   :  87.0 MiB/s
  nettle (lsh's library, from debian)      : 147.1 MiB/s
  openssl (with asm)                       : 263.2 MiB/s

Nettle was actually the last of these that I got into a test harness,
so I was _really_ feeling depressed until then, but, uh... yeah.  That
openssl line isn't a typo.

-- Nathaniel

-- 
"On arrival in my ward I was immediately served with lunch. `This is
what you ordered yesterday.' I pointed out that I had just arrived,
only to be told: `This is what your bed ordered.'"
  -- Letter to the Editor, The Times, September 2000

This email may be read aloud.