AW: Dropbear Server cpu load

[Togg]

Hi Matt,

It doesnt matters if I take blowfish-cbc or aes128. I max get 200kbyte/s.
A timing output in debugging/verbose output would be nice :)

Regards,
Togg

-----Ursprüngliche Nachricht-----
Von: Matt Johnston [mailto:matt at ucc.asn.au] 
Gesendet: Donnerstag, 26. August 2004 05:58
An: Togg
Betreff: Re: Dropbear Server cpu load

On Wed, Aug 25, 2004 at 10:15:06PM +0200, Togg wrote:
> Hi all,
> 
> I am running dropbear daemon on a xscale ixp425 platform (~500 BogoMips)
and
> I have the problem that I only get 200kbyte/s speed during scp to the
> dropbear machine. While transfer dropbear uses 100% cpu.
> 
> In options.h i've optimized for size, but not too aggressively. 
> I undefined dropbear_small_code, no_fast_exptmod, dropbear_blowfish_cbs,
> twofish_cbc and only let aes128 and 3des defined. Dropbear_md5_hmac is
also
> undefined, the rest is default. 
> 
> Any hints? How can I improve speed for filetransfer?

Could you take a look at the output of "ssh -v" (assuming you're using the
OpenSSH client?), it should say which ciphers are actually being used for
the session.  It might be that the LibTomCrypt ciphers are hitting their
speed limits.  I'll take a look at hacking up some raw-cipher/hash timing
code, which might give an indication of where the CPU is used. It might be
worth trying blowfish/twofish, as they _should_ be faster than AES. 3DES
is almost certainly slowest.

Cheers,
Matt