mirror of
https://github.com/cuberite/libevent.git
synced 2025-09-08 11:53:00 -04:00
d4de062efc
Previously, evdns was at the mercy of the user for providing a good entropy source; without one, it would be vulnerable to various active attacks. This patch adds a port of OpenBSD's arc4random() calls to Libevent [port by Chris Davis], and wraps it up a little bit so we can use it more safely.
93 lines
2.9 KiB
C
93 lines
2.9 KiB
C
/*
|
|
* Copyright (c) 2007-2010 Niels Provos and Nick Mathewson
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. The name of the author may not be used to endorse or promote products
|
|
* derived from this software without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
|
|
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
|
|
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
|
|
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
|
|
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
|
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
/* This file has our secure PRNG code. On platforms that have arc4random(),
|
|
* we just use that. Otherwise, we include arc4random.c as a bunch of static
|
|
* functions, and wrap it lightly. We don't expose the arc4random*() APIs
|
|
* because A) they aren't in our namespace, and B) it's not nice to name your
|
|
* APIs after their implementations. We keep them in a separate file
|
|
* so that other people can rip it out and use it for whatever.
|
|
*/
|
|
|
|
#include "event-config.h"
|
|
|
|
#include "util-internal.h"
|
|
#include "evthread-internal.h"
|
|
|
|
#ifdef _EVENT_HAVE_ARC4RANDOM
|
|
#include <stdlib.h>
|
|
int
|
|
evutil_secure_rng_init(void)
|
|
{
|
|
return 0;
|
|
}
|
|
#else /* !_EVENT_HAVE_ARC4RANDOM { */
|
|
|
|
#ifdef _EVENT_ssize_t
|
|
#define ssize_t _EVENT_SSIZE_t
|
|
#endif
|
|
#define ARC4RANDOM_EXPORT static
|
|
#define _ARC4_LOCK() EVLOCK_LOCK(arc4rand_lock, 0)
|
|
#define _ARC4_UNLOCK() EVLOCK_UNLOCK(arc4rand_lock, 0)
|
|
static void *arc4rand_lock;
|
|
|
|
#define ARC4RANDOM_NOSTIR
|
|
#define ARC4RANDOM_NORANDOM
|
|
#define ARC4RANDOM_NOUNIFORM
|
|
|
|
#include "./arc4random.c"
|
|
|
|
int
|
|
evutil_secure_rng_init(void)
|
|
{
|
|
int val;
|
|
if (!arc4rand_lock) {
|
|
EVTHREAD_ALLOC_LOCK(arc4rand_lock, 0);
|
|
}
|
|
|
|
_ARC4_LOCK();
|
|
if (!arc4_seeded_ok)
|
|
arc4_stir();
|
|
val = arc4_seeded_ok ? 0 : -1;
|
|
_ARC4_UNLOCK();
|
|
return val;
|
|
}
|
|
|
|
#endif /* } !_EVENT_HAVE_ARC4RANDOM */
|
|
|
|
void
|
|
evutil_secure_rng_get_bytes(void *buf, size_t n)
|
|
{
|
|
arc4random_buf(buf, n);
|
|
}
|
|
|
|
void
|
|
evutil_secure_rng_add_bytes(const char *buf, size_t n)
|
|
{
|
|
arc4random_addrandom((const unsigned char*)buf, n);
|
|
}
|
|
|