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Diffstat (limited to 'libs/libevent/src/evutil_rand.c')
| -rw-r--r-- | libs/libevent/src/evutil_rand.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/libs/libevent/src/evutil_rand.c b/libs/libevent/src/evutil_rand.c new file mode 100644 index 0000000000..046a14b07a --- /dev/null +++ b/libs/libevent/src/evutil_rand.c @@ -0,0 +1,206 @@ +/* + * Copyright (c) 2007-2012 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 "event2/event-config.h" +#include "evconfig-private.h" + +#include <limits.h> + +#include "util-internal.h" +#include "evthread-internal.h" + +#ifdef EVENT__HAVE_ARC4RANDOM +#include <stdlib.h> +#include <string.h> +int +evutil_secure_rng_set_urandom_device_file(char *fname) +{ + (void) fname; + return -1; +} +int +evutil_secure_rng_init(void) +{ + /* call arc4random() now to force it to self-initialize */ + (void) arc4random(); + return 0; +} +#ifndef EVENT__DISABLE_THREAD_SUPPORT +int +evutil_secure_rng_global_setup_locks_(const int enable_locks) +{ + return 0; +} +#endif +static void +evutil_free_secure_rng_globals_locks(void) +{ +} + +static void +ev_arc4random_buf(void *buf, size_t n) +{ +#if defined(EVENT__HAVE_ARC4RANDOM_BUF) && !defined(__APPLE__) + arc4random_buf(buf, n); + return; +#else + unsigned char *b = buf; + +#if defined(EVENT__HAVE_ARC4RANDOM_BUF) + /* OSX 10.7 introducd arc4random_buf, so if you build your program + * there, you'll get surprised when older versions of OSX fail to run. + * To solve this, we can check whether the function pointer is set, + * and fall back otherwise. (OSX does this using some linker + * trickery.) + */ + { + void (*tptr)(void *,size_t) = + (void (*)(void*,size_t))arc4random_buf; + if (tptr != NULL) { + arc4random_buf(buf, n); + return; + } + } +#endif + /* Make sure that we start out with b at a 4-byte alignment; plenty + * of CPUs care about this for 32-bit access. */ + if (n >= 4 && ((ev_uintptr_t)b) & 3) { + ev_uint32_t u = arc4random(); + int n_bytes = 4 - (((ev_uintptr_t)b) & 3); + memcpy(b, &u, n_bytes); + b += n_bytes; + n -= n_bytes; + } + while (n >= 4) { + *(ev_uint32_t*)b = arc4random(); + b += 4; + n -= 4; + } + if (n) { + ev_uint32_t u = arc4random(); + memcpy(b, &u, n); + } +#endif +} + +#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) +#ifndef EVENT__DISABLE_THREAD_SUPPORT +static void *arc4rand_lock; +#endif + +#define ARC4RANDOM_UINT32 ev_uint32_t +#define ARC4RANDOM_NOSTIR +#define ARC4RANDOM_NORANDOM +#define ARC4RANDOM_NOUNIFORM + +#include "./arc4random.c" + +#ifndef EVENT__DISABLE_THREAD_SUPPORT +int +evutil_secure_rng_global_setup_locks_(const int enable_locks) +{ + EVTHREAD_SETUP_GLOBAL_LOCK(arc4rand_lock, 0); + return 0; +} +#endif + +static void +evutil_free_secure_rng_globals_locks(void) +{ +#ifndef EVENT__DISABLE_THREAD_SUPPORT + if (arc4rand_lock != NULL) { + EVTHREAD_FREE_LOCK(arc4rand_lock, 0); + arc4rand_lock = NULL; + } +#endif + return; +} + +int +evutil_secure_rng_set_urandom_device_file(char *fname) +{ +#ifdef TRY_SEED_URANDOM + ARC4_LOCK_(); + arc4random_urandom_filename = fname; + ARC4_UNLOCK_(); +#endif + return 0; +} + +int +evutil_secure_rng_init(void) +{ + int val; + + ARC4_LOCK_(); + if (!arc4_seeded_ok) + arc4_stir(); + val = arc4_seeded_ok ? 0 : -1; + ARC4_UNLOCK_(); + return val; +} + +static void +ev_arc4random_buf(void *buf, size_t n) +{ + arc4random_buf(buf, n); +} + +#endif /* } !EVENT__HAVE_ARC4RANDOM */ + +void +evutil_secure_rng_get_bytes(void *buf, size_t n) +{ + ev_arc4random_buf(buf, n); +} + +void +evutil_secure_rng_add_bytes(const char *buf, size_t n) +{ + arc4random_addrandom((unsigned char*)buf, + n>(size_t)INT_MAX ? INT_MAX : (int)n); +} + +void +evutil_free_secure_rng_globals_(void) +{ + evutil_free_secure_rng_globals_locks(); +} |