mirror of
https://github.com/qemu/qemu.git
synced 2024-11-26 12:23:36 +08:00
11259e9adc
Explicitly ignore the return value of qemu_guest_getrandom. Because we use error_fatal, all errors are already caught. Fixes: CID 1401701 Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-Id: <20190530173824.30699-1-richard.henderson@linaro.org> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
94 lines
2.3 KiB
C
94 lines
2.3 KiB
C
/*
|
|
* QEMU guest-visible random functions
|
|
*
|
|
* Copyright 2019 Linaro, Ltd.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License as published by the Free
|
|
* Software Foundation; either version 2 of the License, or (at your option)
|
|
* any later version.
|
|
*/
|
|
|
|
#include "qemu/osdep.h"
|
|
#include "qemu-common.h"
|
|
#include "qemu/cutils.h"
|
|
#include "qapi/error.h"
|
|
#include "qemu/guest-random.h"
|
|
#include "crypto/random.h"
|
|
|
|
|
|
static __thread GRand *thread_rand;
|
|
static bool deterministic;
|
|
|
|
|
|
static int glib_random_bytes(void *buf, size_t len)
|
|
{
|
|
GRand *rand = thread_rand;
|
|
size_t i;
|
|
uint32_t x;
|
|
|
|
if (unlikely(rand == NULL)) {
|
|
/* Thread not initialized for a cpu, or main w/o -seed. */
|
|
thread_rand = rand = g_rand_new();
|
|
}
|
|
|
|
for (i = 0; i + 4 <= len; i += 4) {
|
|
x = g_rand_int(rand);
|
|
__builtin_memcpy(buf + i, &x, 4);
|
|
}
|
|
if (i < len) {
|
|
x = g_rand_int(rand);
|
|
__builtin_memcpy(buf + i, &x, i - len);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int qemu_guest_getrandom(void *buf, size_t len, Error **errp)
|
|
{
|
|
if (unlikely(deterministic)) {
|
|
/* Deterministic implementation using Glib's Mersenne Twister. */
|
|
return glib_random_bytes(buf, len);
|
|
} else {
|
|
/* Non-deterministic implementation using crypto routines. */
|
|
return qcrypto_random_bytes(buf, len, errp);
|
|
}
|
|
}
|
|
|
|
void qemu_guest_getrandom_nofail(void *buf, size_t len)
|
|
{
|
|
(void)qemu_guest_getrandom(buf, len, &error_fatal);
|
|
}
|
|
|
|
uint64_t qemu_guest_random_seed_thread_part1(void)
|
|
{
|
|
if (deterministic) {
|
|
uint64_t ret;
|
|
glib_random_bytes(&ret, sizeof(ret));
|
|
return ret;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
void qemu_guest_random_seed_thread_part2(uint64_t seed)
|
|
{
|
|
g_assert(thread_rand == NULL);
|
|
if (deterministic) {
|
|
thread_rand =
|
|
g_rand_new_with_seed_array((const guint32 *)&seed,
|
|
sizeof(seed) / sizeof(guint32));
|
|
}
|
|
}
|
|
|
|
int qemu_guest_random_seed_main(const char *optarg, Error **errp)
|
|
{
|
|
unsigned long long seed;
|
|
if (parse_uint_full(optarg, &seed, 0)) {
|
|
error_setg(errp, "Invalid seed number: %s", optarg);
|
|
return -1;
|
|
} else {
|
|
deterministic = true;
|
|
qemu_guest_random_seed_thread_part2(seed);
|
|
return 0;
|
|
}
|
|
}
|