#include "lib.h"
#include "randgen.h"
#include <stdlib.h>
#ifdef DEV_URANDOM_PATH
#include "fd-close-on-exec.h"
#include <unistd.h>
#include <fcntl.h>
static int init_refcount = 0;
static int urandom_fd;
void random_fill(void *buf, size_t size)
{
size_t pos;
ssize_t ret;
i_assert(init_refcount > 0);
i_assert(size < SSIZE_T_MAX);
for (pos = 0; pos < size; ) {
ret = read(urandom_fd, (char *) buf + pos, size - pos);
if (unlikely(ret <= 0)) {
if (ret == 0)
i_fatal("EOF when reading from "DEV_URANDOM_PATH);
else if (errno != EINTR)
i_fatal("read("DEV_URANDOM_PATH") failed: %m");
} else {
pos += ret;
}
}
}
void random_init(void)
{
unsigned int seed;
if (init_refcount++ > 0)
return;
urandom_fd = open(DEV_URANDOM_PATH, O_RDONLY);
if (urandom_fd == -1) {
if (errno == ENOENT) {
i_fatal(DEV_URANDOM_PATH" doesn't exist, "
"currently we require it");
} else {
i_fatal("Can't open "DEV_URANDOM_PATH": %m");
}
}
random_fill(&seed, sizeof(seed));
srandom(seed);
fd_close_on_exec(urandom_fd, TRUE);
}
void random_deinit(void)
{
if (--init_refcount > 0)
return;
(void)close(urandom_fd);
urandom_fd = -1;
}
#elif defined(HAVE_OPENSSL_RAND_H)
#include <openssl/rand.h>
#include <openssl/err.h>
static const char *ssl_last_error(void)
{
unsigned long err;
char *buf;
size_t err_size = 256;
err = ERR_get_error();
if (err == 0)
return strerror(errno);
buf = t_malloc(err_size);
buf[err_size-1] = '\0';
ERR_error_string_n(err, buf, err_size-1);
return buf;
}
void random_fill(void *buf, size_t size)
{
if (RAND_bytes(buf, size) != 1)
i_fatal("RAND_pseudo_bytes() failed: %s", ssl_last_error());
}
void random_init(void)
{
unsigned int seed;
if (RAND_status() == 0) {
i_fatal("Random generator not initialized: "
"Install egd on /var/run/egd-pool");
}
random_fill(&seed, sizeof(seed));
srandom(seed);
}
void random_deinit(void) {}
#else
# error No random number generator, use eg. OpenSSL.
#endif
void random_fill_weak(void *buf, size_t size)
{
unsigned char *cbuf = buf;
for (; size > 0; size--)
*cbuf++ = (unsigned char)random();
}