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Try to gather entropy from /dev/random.

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wkj 2004-04-21 03:06:03 +00:00
parent 551445b92c
commit 60d3db8e6b
1 changed files with 21 additions and 0 deletions
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src/lib9/truerand.c Normal file
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#include <u.h>
#include <libc.h>
ulong
truerand(void)
{
int i, n;
uchar buf[sizeof(ulong)];
static int randfd = -1;
if(randfd < 0){
randfd = open("/dev/random", OREAD);
fcntl(randfd, F_SETFD, FD_CLOEXEC);
}
if(randfd < 0)
sysfatal("can't open /dev/random: %r");
for(i=0; i<sizeof(buf); i += n)
if((n = readn(randfd, buf+i, sizeof(buf)-i)) < 0)
sysfatal("can't read /dev/random: %r");
return *((ulong*)buf);
}