libzmq/tweetnacl/contrib/randombytes/devurandom.c
Jonathan Reams d1881acbdc Clean up after using randombytes from libsodium
When Curve authentication is used, libsodium opens a file
descriptor to /dev/urandom to generate random bytes. When
the ZMQ context terminates, it should ensure that file gets
closed.
2014-08-31 13:30:44 -04:00

45 lines
678 B
C

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
/* it's really stupid that there isn't a syscall for this */
static int fd = -1;
void randombytes(unsigned char *x,unsigned long long xlen)
{
int i;
if (fd == -1) {
for (;;) {
fd = open("/dev/urandom",O_RDONLY);
if (fd != -1) break;
sleep(1);
}
}
while (xlen > 0) {
if (xlen < 1048576) i = xlen; else i = 1048576;
i = read(fd,x,i);
if (i < 1) {
sleep(1);
continue;
}
x += i;
xlen -= i;
}
}
int randombytes_close(void)
{
int rc = -1;
if(fd != -1 && close(fd) == 0) {
fd = -1;
rc = 0;
}
return rc;
}