[svlug] Sheevaplug ?

Don Marti dmarti at zgp.org
Wed Oct 21 20:00:21 PDT 2009


begin Will Ashford quotation of Wed, Oct 21, 2009 at 03:58:06PM -0700:
> On Wed, Oct 21, 2009 at 3:40 PM, Rick Moen <rick at linuxmafia.com> wrote:
> > Quoting Greg Lindahl (lindahl at pbm.com):
> >
> >> I believe that the Sheevaplug does lack FP, but most (all?) crypto
> >> algorithms don't use FP.
> >
> > I'd be somewhat gobsmacked, if that latter were the case.  I've just
> > done some Web-searching on "openssl fpu" and "gnutls fpu" and it sure
> > looks to me like they use common FPUs.  (This is not an area where I
> > have any particular expertise, so my surmise based on a couple of
> > minutes of searching might be mistaken.)
> 
> Symmetric ciphers in general (AES, Blowfish, etc), do not use float
> point arithmetic. Asymmetric ciphers (like our friends RSA and DSA)
> are almost entirely floating point computations. The majority of
> asymmetric crypto is used at SSL (or SSH) session initiation, after
> that symmetric is used. I would be interesting in knowing how long it
> takes a sheevaplug to do openvpn (or other SSL type connection) setup.

This is one reason why SSH multiplexing is your
friend.  In ~/.ssh/config, put something like:

Host slow.example.org
    ControlMaster auto 
    ControlPath /tmp/%r@%h:%p

Then do something like:

ssh -o ControlMaster=yes slow.example.org

in your _first_ ssh connection to the ARM box.
On a slow ARM, without multiplexing:

    $ time ssh $HOST true
    real    0m1.660s

With multiplexing, master up:

    $ time ssh $HOST true
    real    0m0.214s

-- 
Don Marti                                 +1 510-332-1587 mobile
http://zgp.org/~dmarti/
dmarti at zgp.org




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