The Tor Browser: ipc/chromium/src/third_party/libevent/evutil

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

     1 /*

     2  * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson

     3  *

     4  * Redistribution and use in source and binary forms, with or without

     5  * modification, are permitted provided that the following conditions

     6  * are met:

     7  * 1. Redistributions of source code must retain the above copyright

     8  *    notice, this list of conditions and the following disclaimer.

     9  * 2. Redistributions in binary form must reproduce the above copyright

    10  *    notice, this list of conditions and the following disclaimer in the

    11  *    documentation and/or other materials provided with the distribution.

    12  * 3. The name of the author may not be used to endorse or promote products

    13  *    derived from this software without specific prior written permission.

    14  *

    15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

    16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

    17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

    18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,

    19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

    20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

    21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

    22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

    23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

    24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

    25  */

    27 /* This file has our secure PRNG code.  On platforms that have arc4random(),

    28  * we just use that.  Otherwise, we include arc4random.c as a bunch of static

    29  * functions, and wrap it lightly.  We don't expose the arc4random*() APIs

    30  * because A) they aren't in our namespace, and B) it's not nice to name your

    31  * APIs after their implementations.  We keep them in a separate file

    32  * so that other people can rip it out and use it for whatever.

    33  */

    35 #include "event2/event-config.h"

    37 #include <limits.h>

    39 #include "util-internal.h"

    40 #include "evthread-internal.h"

    42 #ifdef _EVENT_HAVE_ARC4RANDOM

    43 #include <stdlib.h>

    44 #include <string.h>

    45 int

    46 evutil_secure_rng_init(void)

    47 {

    48 	/* call arc4random() now to force it to self-initialize */

    49 	(void) arc4random();

    50 	return 0;

    51 }

    52 int

    53 evutil_secure_rng_global_setup_locks_(const int enable_locks)

    54 {

    55 	return 0;

    56 }

    58 static void

    59 ev_arc4random_buf(void *buf, size_t n)

    60 {

    61 #if defined(_EVENT_HAVE_ARC4RANDOM_BUF) && !defined(__APPLE__)

    62 	return arc4random_buf(buf, n);

    63 #else

    64 	unsigned char *b = buf;

    66 	/* Make sure that we start out with b at a 4-byte alignment; plenty

    67 	 * of CPUs care about this for 32-bit access. */

    68 	if (n >= 4 && ((ev_uintptr_t)b) & 3) {

    69 		ev_uint32_t u = arc4random();

    70 		int n_bytes = 4 - (((ev_uintptr_t)b) & 3);

    71 		memcpy(b, &u, n_bytes);

    72 		b += n_bytes;

    73 		n -= n_bytes;

    74 	}

    75 	while (n >= 4) {

    76 		*(ev_uint32_t*)b = arc4random();

    77 		b += 4;

    78 		n -= 4;

    79 	}

    80 	if (n) {

    81 		ev_uint32_t u = arc4random();

    82 		memcpy(b, &u, n);

    83 	}

    84 #endif

    85 }

    87 #else /* !_EVENT_HAVE_ARC4RANDOM { */

    89 #ifdef _EVENT_ssize_t

    90 #define ssize_t _EVENT_SSIZE_t

    91 #endif

    92 #define ARC4RANDOM_EXPORT static

    93 #define _ARC4_LOCK() EVLOCK_LOCK(arc4rand_lock, 0)

    94 #define _ARC4_UNLOCK() EVLOCK_UNLOCK(arc4rand_lock, 0)

    95 #ifndef _EVENT_DISABLE_THREAD_SUPPORT

    96 static void *arc4rand_lock;

    97 #endif

    99 #define ARC4RANDOM_UINT32 ev_uint32_t

   100 #define ARC4RANDOM_NOSTIR

   101 #define ARC4RANDOM_NORANDOM

   102 #define ARC4RANDOM_NOUNIFORM

   104 #include "./arc4random.c"

   106 #ifndef _EVENT_DISABLE_THREAD_SUPPORT

   107 int

   108 evutil_secure_rng_global_setup_locks_(const int enable_locks)

   109 {

   110 	EVTHREAD_SETUP_GLOBAL_LOCK(arc4rand_lock, 0);

   111 	return 0;

   112 }

   113 #endif

   115 int

   116 evutil_secure_rng_init(void)

   117 {

   118 	int val;

   120 	_ARC4_LOCK();

   121 	if (!arc4_seeded_ok)

   122 		arc4_stir();

   123 	val = arc4_seeded_ok ? 0 : -1;

   124 	_ARC4_UNLOCK();

   125 	return val;

   126 }

   128 static void

   129 ev_arc4random_buf(void *buf, size_t n)

   130 {

   131 	arc4random_buf(buf, n);

   132 }

   134 #endif /* } !_EVENT_HAVE_ARC4RANDOM */

   136 void

   137 evutil_secure_rng_get_bytes(void *buf, size_t n)

   138 {

   139 	ev_arc4random_buf(buf, n);

   140 }

   142 #ifndef __OpenBSD__

   143 void

   144 evutil_secure_rng_add_bytes(const char *buf, size_t n)

   145 {

   146 	arc4random_addrandom((unsigned char*)buf,

   147 	    n>(size_t)INT_MAX ? INT_MAX : (int)n);

   148 }

   149 #endif

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