diff options
Diffstat (limited to 'rnd.c')
-rw-r--r-- | rnd.c | 49 |
1 files changed, 49 insertions, 0 deletions
@@ -0,0 +1,49 @@ +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <unistd.h> + +#include "rnd.h" + +static int fd_rnd = -1; + +static void randombytes(unsigned char *x, unsigned long long xlen) +{ + int ret; + + if (fd_rnd == -1) { + for (;;) { + fd_rnd = open("/dev/urandom", O_RDONLY); + if (fd_rnd != -1) + break; + sleep(1); + } + } + + while (xlen > 0) { + if (xlen < 1048576) + ret = xlen; + else + ret = 1048576; + + ret = read(fd_rnd, x, ret); + if (ret < 1) { + sleep(1); + continue; + } + + x += ret; + xlen -= ret; + } +} + +/* Note: it's not really secure, but the name only suggests it's better to use + * than rand(3) when transferring bytes over the network in non-security + * critical structure members. secrand() is only used to fill up salts actually. + */ +int secrand(void) +{ + int ret; + randombytes((void *) &ret, sizeof(ret)); + return ret; +} |