OpenSSH performance with VIA padlock

Darren Tucker dtucker at
Wed Nov 19 23:20:42 EST 2008

Jan Klod wrote:
> Hello list,
> please spend a minute considering these facts and maybe there is something to 
> improve:
> 1) VIA Eden based board can write AES256 encrypted information on HDD at > 
> 60MB/s
> 2) iperf shows NIC speed 69MB/s
> 3) openssl tests have even better results
> 4) openssh can transfer AES256 encrypted information at < 27MB/s (and worse 
> with HDD encryption)
> It is better with openssh 5.x, than 4.6, but still I see no reason why results 
> are so bad... Please, could someone explain? I don't believe, padlock is used 
> properly...

Did you enable OpenSSL engine support when you built OpenSSH? 
(./configure  --with-ssl-engine).

Try this with 5.1p1, apparently some earlier versions didn't work 
properly (I have no such hardware to test).

Also as someone else mentioned, try a faster MAC such as umac64.

Darren Tucker (dtucker at
GPG key 8FF4FA69 / D9A3 86E9 7EEE AF4B B2D4  37C9 C982 80C7 8FF4 FA69
     Good judgement comes with experience. Unfortunately, the experience
usually comes from bad judgement.

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