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/*
* Random supply helper
* Copyright 2004, Clemens Fruhwirth <clemens@endorphin.org>
*
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
static int randomfd = -1;
int openRandom() {
if(randomfd == -1)
randomfd = open("/dev/urandom", O_RDONLY);
return randomfd;
}
/* This method leaks a file descriptor that can be obtained by calling
closeRandom */
int getRandom(char *buf, size_t len)
{
int r = 0;
if(openRandom() == -1) {
perror("getRandom:");
return -EINVAL;
}
while(len) {
int r;
r = read(randomfd,buf,len);
if (-1 == r && errno != -EINTR) {
perror("read: "); return -EINVAL;
}
len-= r; buf += r;
}
return r;
}
void closeRandom() {
if(randomfd != -1) {
close(randomfd);
randomfd = -1;
}
}
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