Re: no data from /dev/random on udb alpha

Sean Hunter (sean@uncarved.co.uk)
Fri, 17 Sep 1999 11:46:56 +0100


/dev/random is a blocking device that won't write anything until it
has enough entropy is in the pool to give you a strong random number.
Try /dev/urandom for an immediate answer.

A fun way to test (that I just did on my alpha) is to do...

dd if=/dev/random count=2048 bs=1 | uuencode /dev/stdout

...and then wiggle your mouse around (feeding entropy into the random
pool). At first I get nothing, but after a while of continuous
wiggling I get one "chunk" of random stuff at a time. If I do the
above with urandom I get a big splurge at a time.

It seems that on intel I get random numbers a bit easier, but as I
only use xterms on the alpha, I suppose I'm not feeding enough
keyboard and mouse input into the console to generate entropy. Could
this be your problem?

Sean

On Fri, Sep 17, 1999 at 10:39:27AM +0200, Robin Elfrink wrote:
>
> Hi,
>
>
> Can anyone tell me why there's no data from /dev/random on linux-alpha?
>
>
> The system is an UDB Multia, running stock redhat-6.0 (kernel 2.2.5). Also
> tried 2.2.11, that doesn't give anything either.
>
> I couldn't find anything alpha architecture specific in
> drivers/char/random.c...
>
>
> ---------- Have a nice day! ----------
> I'd explain it to you, but your brain would explode.
> Robin Elfrink <r.elfrink@autosound.nl>
> ASN AutoSound Nederland B.V.
> IT Department
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.rutgers.edu
> Please read the FAQ at http://www.tux.org/lkml/
>

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/