Messages in this thread | | | Date | Fri, 07 Jan 2005 19:16:30 +0000 | From | Paulo Marques <> | Subject | Re: /dev/random vs. /dev/urandom |
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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
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