lkml.org 
[lkml]   [2005]   [Jan]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: /dev/random vs. /dev/urandom
Ron Peterson wrote:
> When I compile and run the code below, the string of octal characters
> generated by reading /dev/random contains long strings of zeroes. I was
> under the impression that /dev/random is "more random" than
> /dev/urandom, and will block when it runs out of entropy until it
> gathers more. It's only when RAND_LEN is on the largish side that these
> strings of zeroes appear.
>
>[...]
> read( fd, dat, RAND_LEN );
> for( i = 0; i < RAND_LEN; i++ ) {
> dat[i] = (dat[i] & 0x07) + '0';

This is wrong. You must check the return value of read to know how many
bytes have you actually gathered, instead of assuming RAND_LEN...

--
Paulo Marques - www.grupopie.com

"A journey of a thousand miles begins with a single step."
Lao-tzu, The Way of Lao-tzu

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

\
 
 \ /
  Last update: 2005-03-22 14:09    [W:0.089 / U:0.284 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site