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#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <stdio.h>
#include <stdlib.h>
#include <asm/types.h>
#include <linux/random.h>
#include <errno.h>
#include <error.h>
#include <string.h>
char *program_name;
void usage()
{
error(1, 0, "usage: %s [--bytes] <bits>", program_name);
}
int main(int argc, char **argv)
{
argc--, program_name = *argv++;
int multiplier = 1;
int bits;
while (argc > 1) {
if (!strcmp(*argv, "--bytes")) {
multiplier = 8;
} else {
usage();
}
argc--, argv++;
}
if ((argc != 1) || (bits = multiplier * atoi(*argv)) <= 0)
usage();
struct rand_pool_info *output;
int fd = open("/dev/random", O_WRONLY);
if (fd < 0)
error(1, errno, "opening /dev/random");
output = (struct rand_pool_info *) malloc(sizeof(struct rand_pool_info));
output -> entropy_count = bits;
output -> buf_size = 0;
int r = ioctl(fd, RNDADDENTROPY, output);
if (r < 0)
error(1, errno, "ioctl(RNDADDENTROPY)");
return 0;
}
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