passwdgen

Jacek Konieczny jajcus at bnet.pl
Sun Aug 7 10:56:19 CEST 2005


On Sat, Aug 06, 2005 at 09:21:07PM +0200, Jakub Piotr Cłapa wrote:
> > Another question is: does /dev/random have to be so slow? Are any patches 
> > applied to it's code in PLD kernel that could slow it down? It's just I don't 
> > believe that author of passwdgen wrote a program that needs hours to produce 
> > a 10 character password on average system...
> 
> You can feed it and it will produce much more. Generating entropy based 
> only on normal computer usage is not so easy.
> 
> There were two programs which could feed the kernel with entropy from a 
> v4l source or from a soundcard maybe try these?...

Some of modern computer systems (including modern PC machines) have
integrated hardware entropy sources. Unfortunately those drivers don't
add the entropy to /dev/random, but provide other device. When I tried
/dev/amd768_rng on my server, lacking entropy and running 2.4.x kernel,
I found out, that its interface is slightly incompatible with
/dev/random, so some applications worked with that and some did not. And
the kernel internals (like "random" match of netfilter) did not get the
entropy either.

In 2.6 kernel there is a generic /dev/hwrandom device for all of the
drivers, but it doesn't seem to be connected with /dev/random either.

Greets,
        Jacek



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